Whole-Wheat Bread for Human Health [1st ed.] 9783030398224, 9783030398231

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Yosef Dror Ephraim Rimon Reuben Vaida

Whole-Wheat Bread for Human Health

Whole-Wheat Bread for Human Health

Yosef Dror • Ephraim Rimon • Reuben Vaida

Whole-Wheat Bread for Human Health

Yosef Dror The School of Nutritional Sciences The Faculty of Agriculture The Hebrew University of Jerusalem Jerusalem, Israel Reuben Vaida BSc Food Technologist Einat Food Industries Rehovot, Israel

Ephraim Rimon Head of the Gastro-Geriatric Unit Kaplan-Harzfeld Medical Center Gedera, Israel The Hebrew University of Jerusalem Jerusalem, Israel

ISBN 978-3-030-39822-4    ISBN 978-3-030-39823-1 (eBook) https://doi.org/10.1007/978-3-030-39823-1 © Springer Nature Switzerland AG 2020 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

v

His Staple Highness – The Intact Kernel

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Preface

Whole wheat with high kernel envelope content and with relatively small endosperm was the main staple food and the main pillar of the Western civilization during the millennia when the Western civilization evolved. The plethora of anti-oxidant components that are mostly bound to carbohydrates and the related ingredients have protected and enabled the survival of wheat kernel and supported its spreading over the globe. With wheat cultivation, these compounds have sustained the human population. However, during the long run of wheat breeding, wheat was selected for a higher kernel weight and a higher endosperm (starch) content, followed by an extreme decrease in the dietary fiber and a marked reduction in hundreds of compounds, maintaining the anti-oxidant capacity and other compounds with alleviative flour quality of health claim. Along with the history of wheat cultivation and harvesting, wheat flour is consumed unrefined. Since the ancient eras, tiny amounts of wheat flour were refined to produce white flour with a higher quality of dough but with a lower nutritious quality. People have used to believe that white bread is most nutritious than the black whole bread. Such a notion is still believed. The industrial revolution, at the second half of the nineteenth century, enabled mass refining of flour and drove more and more people to consume refined flour and throw away most of the nutritious ingredients embedded in the wheat bran for animal feeding. The main target of the present book is to restore the consumption of the whole-wheat bread for the well-being of the people. In the last two to three decades, the quality of dough and the baking quality of whole flour have tremendously improved by the introduction of a long list of baking improvers and baking technologies. Concomitantly, the nutritious predominance of the whole-wheat flour was gradually explored and published. Thus, the advantage of the whole bread has become a fundamental nutritional recommendation. Even so, whole bread consumption, in most of the countries, covers less than 20% of bread consumption. ix

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Preface

As we clearly show (Chap. 15), the consumption of the whole bread lowers the incidence of many NCD (noncommunicable disease) very significantly. This impact is evaluated by 20 categories of morbidity and cause of mortality, including various vascular disorders and malignancy incidence, based on studies including more than 37 million subjects, within hundreds of studies around the globe. Such an evidence-based effect, produced by consumption of one essential food has presumably never been previously shown. The facts presented here might help to convince health authorities to undertake active measures to recommend and enhance whole bread consumption. We presume that beyond the reduction in the relative risk of morbidity and mortality, by a routine whole bread, it would also reduce the disability years of aging. Such a burden embraces a major load on the individual, his family, and the society which is estimated to have an average of 3 hard life years for each individual. The explanation for such an effect is described in details in this book. The incidence for each of the 19 defined categories of morbidity and mortality has reduced by about 25% (relative risk of 0.75) in subjects consumed whole-wheat bread versus refined-flour bread. The dietary fiber is considered as the major or the sole element supporting the health benefit of the whole bread. Indeed, adequate consumption of the whole bread accomplishes the prevailed inadequate dietary fiber intake. However, the dietary fiber is only part of the whole bread story since it contains a wide plethora of other ingredients and particularly the bound phenolic compounds found in high concentration in the whole bread. The consumption of white bread has severely contradicted the food security fundamental issue that is accepted by all health authorities. This book presents data concerning the composition and the average concentrations of hundreds of the kernel compounds gathered from over 210 publications with further description of these ingredients. Except for the effect of the whole bread on the decrease in the incidence of the main morbidities, some other effects are described such as those of the yellow pigments on ophthalmologic burdens and various ingredients of the whole bread on the aging of cellular activities such as autophagy with its major role in the brain integrity. Adherence to the gluten-free diet (GFD) is an important practice to prevent damage for the celiac wheat-sensitive people that comprise a small population segment (3)-[glucosyl(1->6)]-glucosyl] ester. (d) Diferulic acids (also known as dehydrodiferulic acids) are formed by dimerization of the ferulic acid and found in the cell wall of the plant (Wikipedia)���������������������������������������������������������������������� 185 The sinaptic acid, 32 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. Synaptic acid is a common constituent of plants and fruits. Sinapic acid has shown to exhibit anti-inflammatory function. Sinapic acid belongs to the family of hydroxycinnamic acid derivatives where the benzene ring hydroxylated (HMDB)���������������������������������� 187 The coumaric acid, 19 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. cis-p-coumaric acid is found in coriander. Coumaric acid is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers namely o-coumaric acid, m-coumaric acid, and p-coumaric acid that differ by the position of the hydroxy substitution of the phenyl group. p-coumaric acid is the most abundant isomer of the 3 in nature. cis-p-coumaric acid belongs to the family of hydroxycinnamic acid derivatives. These are compounds containing a cinnamic acid derivative where the benzene ring is hydroxylated (HMDB)������������������������������������������������������������������������ 187 The vanillic acid (18 μg/g in wheat kernel (Table 8.2) shown in two graphical presentations. Vanillic acid is a phenolic acid found in some forms of vanilla and many other plant extracts. The vanillic acid is a flavoring compound and scent agent that produces a pleasant, creamy odor. It is the intermediate product in the two-step bioconversion of the ferulic acid to vanillin. The vanillic acid, which is chlorogenic acid, is an oxidized form of vanillin. It is also an intermediate in the production of the vanillin from the ferulic acid (HMDB)������������������������������������ 188 The syringic acid, 9–18 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. Syringic acid is a phenol present in some distilled alcoholic beverages. Syringic acid is a product of the gut metabolism of anthocyanins and other polyphenols that consumed fruits and alcoholic beverages. The syringic acid correlated with high anti-oxidant activity and inhibition of LDL oxidation (HMDB) ���������������������������������������� 188 The caffeic acid, 1.3 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. Caffeic acid is a polyphenol present in normal human urine positively correlated to coffee consumption and influenced by the dietary intake of diverse types of food������������������������������������������������ 189

List of Figures

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Fig. 9.13 The cinnamic acid, shown in two graphical resentations. Cinnamic acid It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in several plants. It exists as both a cis and a trans isomer, although the latter is more common (HMDB) ���������������������� 189 Fig. 9.14 Tannins, total tannins content of 450 μg/g in the wheat kernel (Table 8.2). Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. The term tannin refers to the source of tannins used in tanning animal hides into leather; however, the term is widely applied to any large polyphenolic compound containing sufficient hydroxyls and other groups (such as carboxyls) to form strong complexes with the proteins and the other macromolecules. The tannins have molecular weights in the range of 500 – >3000. Tannins usually divided into hydrolyzable tannins and condensed tannins (proanthocyanidins). At the center of a hydrolyzable tannin molecule, there is a polyol carbohydrate (usually D-glucose). The hydroxyl groups of the carbohydrate partially or esterified with the phenolic groups such as gallic acid (in gallo-tannins) or ellagic acid (in ellagi-tannins). Hydrolyzable tannins hydrolyzed by the weak acids or the weak bases to produce carbohydrate and phenolic acids. The condensed tannins, also known as pro-anthocyanidins, are polymers of 2–50 (or more) flavonoid units that joined by the carbon-carbon bonds, which are not susceptible to being cleaved by hydrolysis. While hydrolyzable tannins and most condensed tannins are water-soluble, some very large condensed tannins are insoluble (HMDB) �������������������������������� 190 Fig. 9.15 Flavonoids, total flavonoids content is 470 μg/g in the wheat kernel (Table 8.2). Flavonoids are a group of plant metabolites thought to provide health benefits through cell signaling pathways and anti-oxidant effects. These molecules found in a variety of fruits and vegetables. Flavonoids are polyphenolic molecules containing 15 carbon atoms and are soluble in water (Wikipedia)���������������������� 192 Fig. 9.16 Pelargonidin is a type of anthoxyans, The total anthocyanins content is 150 μg/g in the wheat kernel (Table 8.2). Pelargonidin is an anthocyanin (one of six), with an anti-oxidant and produces a characteristic orange color �������������������������������������������������������������� 192 Fig. 9.17 Chalcone, shown in two graphical presentations. Chalcone as is the flavone fraction of the dietary items. Chalcone is an aromatic ketone and an enone that forms the central core for a variety of important biological compounds, which known collectively as chalcones or chalconoids. Benzylideneacetophenone

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Fig. 9.18

Fig. 9.19

Fig. 9.20

Fig. 9.21

Fig. 9.22

Fig. 9.23

List of Figures

is the parent member of the chalcone series. Chalcones and their derivatives demonstrate wide range of the biological activities such as anti- oxidant, -diabetic, -neoplastic, -hypertensive, -retroviral, -inflammatory, -parasitic, -histaminic, -malarial, -fungal, -obesity, -platelet, -tubercular, immunosuppressant, -arrhythmic, -gout, anxiolytic, -spasmodic, -nociceptive, hypolipidemic, -filarial, -angiogenic, -protozoal, -bacterial, -steroidal, and cardioprotective���������������������������������������������������������� 193 The plant lignans (Adlercreutz 2007; Peterson et al. 2010), The matairesinol shown in two graphical presentations. (a) Actigenin. (b) Hydroxymatairesinol. (c) Secoisolariciresinol. (d) Syringaresinol. (e) Matairesinol���������������������������������������������������� 194 The mammalian lignans (Peterson et al. 2010), shown in two graphical presentations. (a) Enterodiol is one of the most important lignan-type phytoestrogens identified in the serum, urine, bile, and seminal fluids of humans and animals. Phytoestrogens are a diverse group of compounds found in many edible plants that have, as their common denominator, a phenolic group that they share with estrogenic steroids. This phenolic group appears to play an important role in determining the estrogenic agonist/antagonistic properties of these compounds. Phytoestrogens have categorized according to their chemical structures as isoflavones and lignans. The enterodiol formed by bacteria in the intestinal tract from the plant lignans matairesinol and secoisolariciresinol, which exist in various whole-­grain cereals. (b) Enterolactone���������������������� 196 Samples of derivatives of the benzoxazinoids present in the wheat kernel, 2 on the upper panel and 10 on the middle panel. On the lower panel a typical metabolite present in the human urine. Content on the wheat kernel is 5 μg/g (Table 9.2) (Tanwir et al. 2013)���������������������������������������������������������������������������� 199 α-resorcylic, a primary metabolite of the alkylresorcinols, shown in two graphical presentations. 3,5-dihydroxybenzoic acid, also known as α-resorcylic acid or α-resorcylate, belongs to the hydroxybenzoic acid derivatives class of compounds. Those are compounds ontaining a hydroxybenzoic acid (or a derivative), which is a benzene ring bearing a carboxyl and hydroxyl groups. 3,5-dihydroxybenzoic acid is soluble (in water) and a weakly acidic compound. It is a metabolite of alkylresorcinols������������������������������������������������������������������������������ 200 The alkylresorcinol with the side chain containing 17 (C:17), 19, 21, 23 and 25 carbon units; the content in the wheat kernel is 420 μg/g (Table 8.2). (Landberg et al. 2014). The alkylresorcinols are relatively rare in nature, with the main known sources being wheat, rye, barley, triticale (cereal grasses) (HMDB)������������������������ 201 DHPPA. C9H10O4�������������������������������������������������������������������������������� 202

List of Figures

xxxv

Fig. 11.1 The policosanol, shown in two graphical presentations. 1-octacosanol (also known as n-octacosanol; octacosyl alcohol; cluytyl alcohol; or montanyl alcohol) is a straight-chain aliphatic 28-C primary fatty alcohol. This compound is common in the epicuticular waxes of the plants, including the leaves of many species of Eucalyptus, of most of the forage and cereal grasses, of acacia, trifolium, pisum, and many other legume genera among many others, sometimes as the major wax constituent. The octacosanol also occurs in the wheat germ and it is insoluble in water but freely soluble in low-molecular-weight alkanes and chloroform. These are aliphatic alcohols consisting of a chain of 8 to 22 C atoms (HMDB)������������������������������������������������������ 229 Fig. 12.1 The phytic acid and the inositol. (a) Myo-inositol hexakisphosphate is an intermediate in the inositol phosphate metabolism. It can be generated from D-myo-inositol 1,3,4,5,6pentakisphosphate via the enzyme inositol-pentakisphosphate 2-kinase. The myo-­inositol hexakisphosphate known as phytic acid. It can use clinically as a complexing agent for removal of the traces of the heavy metal ions. It acts also as a hypocalcemic agent. The phytic acid is a strong chelator of important minerals such as calcium, magnesium, iron, and zinc and can contribute to the mineral deficiencies in the developing countries. For people with a particularly low intake of essential minerals, especially young children and those in developing countries, this effect can be undesirable. The dietary mineral chelators help prevent over-mineralization of the joints, the blood vessels, and other parts of the body, which is most common in the older persons. The phytic acid may consider a phytonutrient, providing an anti-oxidant effect (Wikipedia). (b) The inositol phosphate is an intermediate step in the metabolism of the glucose-6phosphate to myo-inositol. The myoinositol synthesized from the glucose-6-phosphate (G-6-P) in 2 steps. First, the G-6-P isomerized to myoinositol 1-phosphate, which then dephosphorylated to give myoinositol���������������������������������������� 233 Fig. 12.2 The oxalic acid is a dicarboxylic acid with the formula C2H2O4. It occurs naturally in many foods, but excessive ingestion of the oxalic acid or prolonged skin contact can be dangerous. Blood concentration is ~1.2 μg/mL���������������������������������������������������� 237 Fig. 14.1 Schematic representation of the gastrointestinal tract (GIT). The GIT segments: 1. oral cavity; 2. esophagus; stomach segments: (3. fundus; 4. stomach body; 5. pyloric part; and 6. pyloric sphincter); 7. duodenum; 8. jejunum; 9. ileum; 10. terminal ileum; 11. ileocecal sphincter; 12. cecum; 13. ascending colon; 14. right transverse colon; 15. left transverse

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Fig. 14.2 Fig. 14.3 Fig. 14.4

Fig. 14.5

List of Figures

colon; 16. descending colon; 17. sigmoid colon; 18. rectum; 19. anus; and 20. anal sphincter Located outside the gastrointestinal tract: liver, common bile duct, gall bladder, and pancreas (lays near the pyloric sphincter, not shown), cecal appendix, diverticula, and polyps (the last 2 projections located outside and inside the GIT, respectively), but mainly on the sigmoid colon�������������������������������������������������������������������������� 274 On the left - the black holes show the openings of the diverticula; on the right - a sigmoid polyp (from the surgery of ER)�������������������� 276 The prevalence of diverticulosis in a sample of Rome subjects (n = 1090), by age (Cecco et al. 2016)������������������������������������������������ 277 The 4 main forms of the bile acids (a) Cholic acid (cholate): Cholic acid is a major primary bile acid produced in the liver and is usually conjugated with glycine or taurine. It facilitates fat absorption and cholesterol excretion. Bile acids are steroid acids found predominantly in the bile of mammals. The distinction between different bile acids is a minute and depends only on the presence or absence of hydroxyl groups on positions 3, 7, and 12. Bile acids are physiological detergents that facilitate excretion, absorption, and transport of fats and sterols in the intestine and liver. Bile acids are also steroidal amphipathic molecules derived from the catabolism of cholesterol. They modulate bile flow and lipid secretion, are essential for the absorption of dietary fats and vitamins and have been implicated in the regulation of all the key enzymes involved in cholesterol homeostasis. Bile acids recirculate through the liver, bile ducts, small intestine, and portal vein to form an enterohepatic circuit. They exist as anions at physiological pH and consequently require a carrier for transport across the membranes of the enterohepatic tissues. The unique detergent properties of bile acids are essential for the digestion and intestinal absorption of hydrophobic nutrients. Bile acids have potent toxic properties and there are a plethora of mechanisms to limit their accumulation in blood and tissues. Among the primary bile acids, cholic acid is considered to be the least hepatotoxic while deoxycholic acid is the most hepatoxic (HMDB). (b) Deoxycholic acid: Deoxycholic acid is a secondary bile acid produced in the liver and is usually conjugated with glycine or taurine. (c) Chenodeoxycholic acid. (d) Lithocholic acid, also known as 3α-hydroxy-5β-cholan-24-oic acid or LCA, is a secondary bile acid. It is formed from chenodeoxycholate by bacterial action ������������������������������������������������������������������������������ 287 The main 2 amino acids with a high tendency to form bile salts: glycine and taurine�������������������������������������������������������������������� 289

List of Figures

xxxvii

Fig. 15.1 The incidence of colorectal cancer by age. Upper panel – the incidence of hospitalization because of colorectal cancer in the US (Sonnenberg and Byrd-Clark 2014). Lower panel – incidence in Israel (Barchana et al. 2004)������������������ 316 Fig. 17.1 Distribution of alkylresorcinol chain-length in cereal kernels (Landberg et al. 2009; Ross et al. 2003; Geerkens et al. 2015; Andersson et al. 2010a; Andersson et al. 2010b; Chen et al. 2004; Kulawinek et al. 2008; Landberg et al. 2006)�������������������������������������������������������������������������� 356 Fig. 22.1 Acrylamide, shown in two graphical presentations���������������������������� 399

List of Tables

Table 1.1 The main ingredients of the kernel organs (Hemery et al. 2009)����������������������������������������������������������������������    3 Table 1.2 The global grain production 2016 (FAOSTAT)������������������������������   14 Table 3.1 The global cereal production and other starchy foods, M ton/y (FAOSTAT)����������������������������������������������������������������������   28 Table 3.2 The global production of the main carbohydrate staple-foods 2012, adjusted for the energy equivalent of the wheat (FAOSTAT)����������������������������������������������������������������   32 Table 3.3 Relative prices received by the farmers in the US. 2016/7. (USDA, Wheat Outlook)����������������������������������������������������������������   38 Table 3.4 The cereal major ingredients�������������������������������������������������������������� 40 Table 4.1 The effect of the extraction rate (refining) on the flour composition (Slavin et al. 1999, 2001)���������������������������������������������� 51 Table 4.2 The milling yield (Gebruers et al. 2008)�������������������������������������������� 52 Table 4.3 The effect of the wheat-flour refining on the dough content of the phenolic acids, carotenoids, and the tocopherols (Lu et al. 2015)�������������������������������������������������� 55 Table 4.4 Bound ferulic acid content (ferulic acid content μg/g of dry sample) and total phenolic content (μg/g) in flour and bread products (average of 5 flour brands and bread products)���������������������������������������������������������������������������� 56 Table 4.5 The anti-oxidant capacity in flour and bread (average of 5 flour brands and bread products) by 3 measures������������������������ 57 Table 4.6 The destruction of the vulnerable ingredients by the milling and the increase in the starch damage������������������������ 60 Table 5.1 The main groups of the kernel micro-ingredients������������������������������ 73 Table 5.2 The wheat kernel volume characterizations, and the concentrations of protein, and amino acids �������������������������� 76

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List of Tables

Table 5.3 Animal protein intake and the ratio between plant protein and animal proteins by the world regions and the economic levels (Vliet et al. 2015)���������������������������������������� 83 Table 5.4 Wheat kernel lipids���������������������������������������������������������������������������� 84 Table 5.5 The wheat kernel minerals������������������������������������������������������������������ 87 Table 6.1 The wheat kernel carbohydrates�������������������������������������������������������� 92 Table 6.2 A comparison between the kernel composition of the carbohydrate and fiber fractions of the main cereals�������������������������� 93 Table 7.1 The fermentability rate of the dietary fiber ingredients in the human colon (Brownlee et al. 2006)�������������������������������������� 109 Table 8.1 The wheat kernel vitamins��������������������������������������������������������������� 140 Table 8.2 The wheat kernel lipophilic anti-oxidants and related ingredient ���������������������������������������������������������������������� 143 Table 8.3 The tocols in the wheat germ oil, μg/g, and percentage, (Malekbala et al. 2017)�������������������������������������������������������������������� 148 Table 8.4 The α- and the γ-tocopherol in edible oils, μg/g (Grilo et al. 2014) ���������������������������������������������������������������������������� 151 Table 8.5 The carotene concentrations in the plasma of the European populations (Eggersdorfer and Wyss 2018)�������������������������������������� 154 Table 8.6 The content of the methyl donors in the wheat kernel and some other cereals��������������������������������������������������������������������� 160 Table 9.1 Plasma alkyresorcinol values collected from the available data������������������������������������������������������������������������������ 203 Table 9.2 The phenolic compounds in the main cereals, μg/g ������������������������ 204 Table 9.3 Phenolic acid variations in the wheat kernel������������������������������������ 210 Table 10.1 The daily polyphenol intake in the Israeli menu (Statistical Abstract of Israel 2016)�������������������������������������������������� 219 Table 12.1 Phytic acid in food items, μg/g�������������������������������������������������������� 232 Table 13.1 The total wheat intake versus the whole-wheat intake in various countries (FAOSTAT: Food and agriculture data) ���������� 242 Table 14.1 The gut segments characterizations�������������������������������������������������� 269 Table 14.2 The dynamics of the GIT flows�������������������������������������������������������� 275 Table 15.1 The effect of the whole-wheat intake on the decrease in the relative risk (RR) of morbidity and mortality as evaluated in 20 categories������������������������������������������������������������ 303 Table 15.2 Summary of the 20 categories (presented in Table 15.1) ���������������� 313 Table 15.3 The incidence of the colorectal malignancy and the prevalence at the colorectal site (Europe, USA, Iceland, Poland, and Israel) ������������������������������������ 318

List of Tables

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Table 18.1 The effect of the yellow pigments on AMD: The decrease in the relative risk (RR) of the incidence of advanced AMD with the plasma concentration or the higher intake of dietary carotenoids in comparison to the lower level������������������ 367 Table 18.2 The decrease in the relative risk (RR) of the cataract incidence with the increase in the dietary intake or the blood concentration of lutein, zeaxanthin and vitamin E �������������������������� 369 Table 21.1 The effect of the high intake of the RTEC on the relative risk (RR) of the morbidity and the mortality, and the RR for overweight incidence ���������������������������������������������� 391 Table 24.1 The daily whole-grain intake in the 28 European countries with a decreasing order for each range�������������������������������������������� 410 Table 25.1 Mesh sieve conversion���������������������������������������������������������������������� 417 Table 25.2 Recipes for the whole-wheat bread�������������������������������������������������� 417

Chapter 1

The Whole-Wheat Bread

The accurate definitions of the whole-grain, the whole-wheat, the whole-wheat flour, or the whole-wheat bread have not reached a general consensus. Some of these definitions presented above. Except for the refined products consumed by the vast majority of the wheat consumers, large populations consume refined rice products. The dominance of the number of refined rice consumers produced by the higher number of rice consumers and because of the lower rate of whole-rice consumption. However, the nutritional epidemiological data for rice consumption are extremely scarce. Therefore, the health issues of rice consumption are only briefly discussed even the impact of the health global effect might be most remarkable than that of wheat consumption. Except for wheat and rice, other whole-grains of the Poaceae species are routinely consumed. The basic composition of the wheat kernel presented in Table 1.1 and further details for the wheat kernel presented in Tables 3.4, 5.1, 5.2, 6.1, 8.1, and 8.2.

1. The motivation to consume the whitest bread that widely enabled by the refining machines and the roller milling followed the industrial revolution have withdrawn the most precious ingredients from our menu and decreased by a half or more the content of the antioxidants and the dietary fiber of our dietary intake. These ingredients embedded in the flour bran are most crucial for our lowest morbidity and highest longevity. 2. Even the knowledge about the health quality of whole-­wheat bread has widely published in last decades, an only a small segment of the populations consume the whole-wheat bread (presumably 2 decades of such of the most extravagant commitment, it will be certainly safe to say that the considerable part of the human deprived of the most sufficient ingredients. People who consume staple food after processing by the wheat refining machines or by the rice polishing machines and refining machines ­continuously deprived of the most nutritious parts of the wheat or the rice kernel and thus become food and nutritional insecure with an elevated relative risk for most of the NCD (non-communicable diseases) and presumably for many other burdens. The refining machines, invented following the industrial revolution, have routinely withdrawn most of the nutritious part of the cereal kernel that contains the majority of the dietary fiber and the crucial micronutrients, outside the human gut and the metabolic pathways. The only limited number of people living in the countries where wheat and rice consumed as staple foods, have routinely fed with the whole-grain products to ensure their food and nutrition security. Within the wheat consumer 25% of the total

Presently, because of the diversion of the wheat and the rice bran from the human menu, for the majority of the wheat and rice consumers, their food and nutrition status has become insecure.

The Foremost Misinterpretation in Human Nutrition

23

wheat production as bran which is mainly wasted for human nutrition and some >10% for rice waste which is no longer used directly for human nutrition. Thus, the total annual waste of these 2 kinds of cereals is some >190 M ton for wheat and >70 M ton for rice. But the catastrophe of the refining practice is much worst, this gigantic nutritious wastage contains ~50% of the total available consumption of the dietary fiber and ~50% of the available consumption of the anti-­ oxidant capacity (Gould 2017). Even the dietary fiber and the cereal anti-oxidants are crucial ingredients to ensure longevity and the low relative risk values for morbidity incidence, the American DRI, and all other dietary recommendations institutions have not defined the total anti-oxidant capacity as an integral part of the recommendations. The dietary guides for the Americans and those published in other countries recommend an intake of at least half of the cereals consumed as whole-grain. Such an amount (of 50%) does not cover the 25 g/d of dietary fiber while to cover such a quota all cereal should derived from the whole-grain. Probably, to ensure the highest effect of the whole-wheat on the population welfare, the energy derived from the whole-grain products should exceed 30% of the total energy intake while currently in some countries, the total energy derived from the grain intake is 90% of the total production, undergoes a polishing process that resulted in the withdrawal of the most nutritious ingredients of the rice grain and with a largescale reduction of the rice yield for human nutrition. Within the last decades, hundreds of scientific articles about the marked nutritional advantage of the whole-wheat have published and continuously warned the nutritionists for the insecurity produced by flour refining. Additionally hundreds of reputed reviews have also intensified the issue with some examples cited here (Angelino et al. 2017; Okarter and Liu 2010; Calinoiu and Vodnar 2018). A search of the terms: “antioxidants and wheat and (grain or kernel)” shows a 6 times linear increase of 20–120 scientific publications between the year 2005–2018 (WOS). The marked disregarding of the food insecurity that generated by the cereal refining sounds from this prestigious report (FAO et al. 2019), delivers a wrong nutritional message to the public.

References Angelino D, Cossu M, Marti A, Zanoletti M, Chiavaroli L, Brighenti F, Rio DD, Martini D (2017) Bioaccessibility and bioavailability of phenolic compounds in bread: a review. Food Funct 8:2368. https://doi.org/10.1039/c7fo00574a Bukkitt D (1971) Epidemiology of cancer of the colon and rectum. Cancer 28:3–13 Calinoiu LF, Vodnar DC (2018) Whole grains and phenolic acids: a review on bioactivity, functionality, health benefits and bioavailability. Nutrients 10:1615. https://doi.org/10.3390/ nu10111615 FAO, IFAD, UNICEF, WEP, WHO (2019) The state of food security and nutrition in the world 2019 Safeguarding against economic slowdowns and downturns. FAO, Rome Frith E, Loprinzi PD (2018) Food insecurity and cognitive function in older adults: brief report. Clin Nutr 37:1765–1768. https://doi.org/10.1016/j.clnu.2017.07.001 Gould J (2017) A world of insecurity. Nature 544:S6–S7 Lin BH, Dong D, Carlson A, Rahkovsky I (2017) Potential dietary outcomes of changing relative prices of healthy and less healthy foods: the case of ready-to-eat breakfast cereals. Food Policy 68:77–88. https://doi.org/10.1016/j.foodpol.2017.01.004 Luan Y, Fischer G, Wada Y, Sun L, Shi P (2018) Quantifying the impact of diet quality on hunger and undernutrition. J Clean Prod 205:432–446. https://doi.org/10.1016/j.jclepro.2018.09.064. Okarter N, Liu RH (2010) Health benefits of whole grain phytochemicals. Crit Rev Food Sci Nutr 50:193–208. https://doi.org/10.1080/10408390802248734 World Food Summit Rome (1996) Rome declaration on world food security. http://www.fao.org/3/ w3613e/w3613e00.htm

Chapter 3

The Wheat in the View of Our Whole-Menu

We showed some examples of how the public overviewed the nutritious quality of the white bread coined as a superior bread. The focal theme of the present book to convert the white bread believers towards whole-wheat consumers.

The Exceptional Effect of the Whole-Wheat on Our Health The cardiovascular, cancer, and diabetes mellitus diseases known as the non-­ communicable diseases with the leading causes of the mortality, morbidity and the number of disability years on aging. These burdens expected to a further increase worldwide with the global aging of the population. The deteriorating of sensible nutrition in the distinct segments of our societies, with the increase in the obesity rate and the other diet-related risk factors, strongly enhance such a trend. The suboptimal diet is now the leading risk factor for the occurrence and the prevalence of the NCD. Even modest dietary changes are associated with meaningful reductions in the cardiovascular diseases morbidity and mortality, diabetes type 2, specific cancer sites and the decrease in some of the biomarkers of the major risk factors for cardiovascular diseases including hypercholesterolemia, hypertension, and obesity (Micha et al. 2015). Such a notion repeats again and again in some reviews that published by the most reputed medical and nutritional journals (Ezzati and Riboli 2013; Kontis et  al. 2014, 2015; Fardet and Boirie 2014). Among all the food items analyzed in hundreds and thousands of studies, the wheat bread is the most predominant one in the weighted consumption and it has the lowest price per energy among other food items.

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_3

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The evident effects of the whole-wheat products shown precisely on the main non-communicable diseases such as colorectal malignancy, upper gut malignancy, all-cause of malignancy, cardiovascular diseases, stroke, hypertension, adiposity, diabetes type 2, hip fracture, and inflammation. Some more data have gathered for the whole-wheat effect on the cognition and immune response, intima-media thickness, appetite, serum LDL, the diversity of the microbiota population, the colon integrity and the production scale of the short-­ chain fatty acids. Some other nutritional factors are accounted as influential effects on human health such as the low intake of fruits, vegetable, nuts, seeds, and some seafood or high intake of salt. However, the effect of the whole-wheat intakes presumably overweighs all other effects (Micha et al. 2015; Ezzati and Riboli 2013). Wheat is a unique food item in the Westernized Societies and comprises 25–40% of all energy intake with the lowest price. The 8 cereal grains namely: wheat, corn, rice, barley, sorghum, oats, rye, and millet provide 56% of the food energy and 50% of the protein consumed by the human on earth. In the US the energy cost of grains is about 75% of that of pulses, sugar, milk, eggs and fat, 34% of that of meat and 23% of that of fruits and vegetables (Drewnowski 2004; Hung 2016). The advantage of the whole-wheat intake for the refined products have noticed a long time ago but some commercial interests tried and succeeded to keep on-going production of the refined wheat as the main staple food rather than whole-grain consumption. An interesting discussion arose within the period of WWI while the shortage of wheat due to the excessive demands of the allied armies has forced the Federal Food Administration in the US to adopt certain policies with a regard to the consumption of the wheat with a campaign to encourage the consumption of the whole-wheat flour. The advocates of this idea argued that by milling a larger portion of the wheat kernel into the flour there would be less bran, shorts and the middlings for use as for stock feed. The wheat would go further as human food, and the amount saved would available to assist in meeting the increased demand for the wheat. The scientists and administrators supporting this view also contended that whole-wheat flour contained certain nutrients that standard flour did not contain and therefore was better food. A counter-campaign was immediately launched by certain bodies of the milling interests represented by the scientist claiming that white bread is the best war bread on account that it is more nutritious than the bread made from 82% extraction flour or flour milled from the entire grain (Graham flour or unrefined flour). They claimed that the whole-wheat flour has the same nutritious quality but it actually harmful, causing diarrhea and digestive disturbances. It expected that the milling interests would take the stand described above, for the people have been educated to believe that light, fluffy, white bread was the best bread for the human consumption, and the milling interests have become organized both in personnel and machinery to give the people what they want, regardless of its advisability (Dutcher 1917). Another example of how the idea of the “most nutritious” quality of the refined bread preserved by the policy-makers and regulator of bread pricing exists in Israel. During October and November, 1942 with the Nazis and the Italian siege on the

The Share of the Wheat in Our Menu

27

Mediterranean, a shortage of wheat supply enforced on Mandatory Palestine. With the increase of bread price, the British Mandatory Government began subsidizing wheat price and imposed price control for the bread baked from the flour with the mild refining rate. Since then within the last 76 y, the price control for the whitebread continually imposed.

The practice of the refining of the wheat flour, highly embedded in Westernized societies. After hundreds of scientific articled have shown the marked advantage of the whole-wheat intake still >80% of the wheat flour routinely refined.

Presently, the bread with high and median refining rate (10,000 species, comprises the vast majority of all cereal in human nutrition. There are some crops of other botanical families such as buckwheat, flaxseed, and quinoa (termed pseudo-cereals) but with minor importance for the world population. In many countries, outside of Western Societies, wheat does not dominate the main energy source while rice, tubers, and corn are the main staple foods (Table 3.1). However, in this book the main talk relates to the effect of the whole-wheat on the health status. The wheat issue has accumulated a considerable volume of documentation that may support our discussion and claims for the advantage of the whole-­ kernel. Because the global rice consumed at some higher quantity than the wheat in human nutrition, evaluation of the effect of the white rice versus the brown rice should contribute an interesting viewpoint and presumably suggests remarkable recommendations for the countries with the rice consumers.

 he Global Production of the Main Carbohydrate T Staple-Foods The whole-cereal grains not confined only for wheat but also for the other cereal grains. Poaceae (cereals) family (>10,000 species) comprises the vast majority of cereal in human nutrition (Table 3.1). Some crops of other botanical families used for human nutrition consumed at considerable amounts. Such crops are buckwheat, flaxseed, and quinoa. Crude calculation shows that cereals supply ~1 kg/d grains for every human being on our planet. This amount supplies about 3400 kcal/d without taking into account all the other food products such as legumes, cassava, potato, bananas, sweet potato, yam, sugar, fruits and vegetables, oil and animal products.

Presently, the wheat comprises 25% of global cereal of human consumption without considering other starchy foods such as legumes, tubers, and banana that with their contribution the wheat share reduced to some 20% of the starchy staple foods of the human menu (Tables 3.1 and 3.2). In many countries in Asia, Africa, and South America, rice, tubers, banana, and corn (maize) might be the predominant staple food. In North America, wheat products comprise some 18% of the total energy intake, in Western Europe 41% and in Israel 30%. The wheat is not the sole cereal in our diet and other whole-flour cereals might contain a preferential composition of the dietary fiber and the escorted compounds. However, only for the wheat, the advantage of whole-­flour cereal upon refinedflour cereal has intensively investigated with tens of millions of observations.

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Table 3.2  The global production of the main carbohydrate staple-foods 2012, adjusted for the energy equivalent of the wheat (FAOSTAT)

Adjusteda Grain M ton/y Rice 760 Wheatb 715 Barley 144 Sorghum 60 Millet 30 Oats 24 Rye 17 Triticalec 15 Sugar 186 Cassava 123 Potato 88 Bananas 35 Sweet potato 37 Yam 21 Wheat bran 90d Corn (maize) 1018

Unadjusted raw values

269 365 144 108 70

Adjusted for the wheat dry matter Wheat comprises 31% of the total grain production c A hybrid of wheat and rye d Onipe et al. (2015) a

b

Such energy quantity overweighs considerably the common human consumption. Corn (maize) comprises the main cereal product worldwide but it consumed at a limited scale in the Western Societies while the major quantity used for animal feed and also for ethanol production. The amount of wheat eaten overweighs all other grain crops consumed by humans in the countries where the large-scaled epidemiological studies have conducted (Table 3.1). Roughly, 95% of the wheat crop is common wheat, used for making bread, cookies, and pastries. The remaining 5% is durum wheat that mainly used for making pasta and other semolina products. The durum and the common wheat are ­polyploidy species that originated by interspecific hybridization of two and three different diploid species, respectively. Today, the hexaploid Triticum aestivum accounts for about 95% of the global wheat crop with most of the remaining 5% being tetraploid durum wheat. The wheat is grown from Norway and Russia at 65°N to Argentina at 50°S and from the areas around the Lake of Galilee at −212 altitude (the earliest known) up to 4500 m. However, in the tropical and the subtropical regions wheat is restricted to the higher elevations areas (Shewry 2009). Some 20% of the world production grown irrigated, 20% with annual rainfall 650 mm/y (Curtis 2002). Within the last 20 y, an average of 3.5% of the annual increase of global wheat production observed with almost no change in the global area harvested. The global production for 2015 is 735 M tons, the harvested area

The Global Production of the Main Carbohydrate Staple-Foods

33

225 M ha with an average yield of 3.27 ton/ha (Wheat Data USDA). The global trade (2015) is 116 M tons and the 10 main importing countries share 40% of the globally imported wheat (Index Mundi). The wheat bread genome contains a very high size of the genetic material. To put the huge size of the bread wheat genome into context, its constituent number of paired DNA bases, or nucleotides, totals of 17,000,000,000 base pairs (17 Gb). This genome contains ~5 times the amount of DNA in the human and ~8 times the amount in corn. However, as much as 80% of the bread wheat genome consists of repetitive sequences. The bread wheat genome is a hexaploidy genome. This means that it has six copies of each of its 7 chromosomes; the complete set numbering 42 chromosomes. In contrast, the human genome is diploid, with 23 pairs of chromosomes. While wheat has fewer pairs of chromosomes than humans, it has a greater number of genes, with an estimated 164–334 k genes, compared to 20–25 k genes in human. With such huge gene library of the common wheat, kernel wheat contains a long list of anti-oxidants and specific anti-malignant compounds that some of them are almost unique for the wheat and most of them are present in the bran at a much higher concentration than in the starchy endosperm (refined flour). The common wheat (T. aestivum), known as the hard- or the soft-wheat, depending on the grain hardness. The grain hardness determined by the way the components packed in the endosperm cells and refers to the resistance that the grain opposes to grain fractured and reduced to fine whole-meal flour or to the fine endosperm particles (semolina or refined flour). Grain hardness is the quality trait associated with the milling properties of the wheat and with the baking quality of the resulting milling products. Native starch, which is the main component of the wheat grain (70–75%), shows little influence on the functional properties of the wheat flours used in bread, cookies, and cake making. The gluten comprises roughly 78–85% of the total protein of the wheat endosperm and responsible for most of the viscoelastic properties of the wheat flour dough. The gluten is the main factor dictating the use of a wheat variety in the bread and the pasta making. The wheat utilized mainly as flour (whole-or refined grain) for the production of a large variety of the leavened and the flatbreads, and for the manufacture of a wide variety of other baking products. The rest is mostly the durum wheat (T. durum), which is used to produce semolina (coarse flour), and the main raw material of pasta making. Some durum wheat milled into flour to manufacture medium-dense bread in the Mediterranean and the Middle Eastern countries and some of the coarse durum grain grits used to produce couscous (cooked grits) in the Arab countries. Wheat, in the form of bread, provides more nutrients to the world population than any other single food source (Peña 2002). Kernel weight of the main crops of the wheat, oat, and rye are in the range of 32–37 g per 1000 grains. Rice weight is lower and stays in the range of 24 g.

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The Staple Foods In Western Societies, rice, wheat, corn (maize), barley, oats, rye, and triticale comprise the vast majority of the starchy cereal of human menu. In China, wheat comprises ~39% (2014) of the total amount of rice and wheat (Table 3.1). A considerable amount of cereal crops (mainly corn, barley, sorghum, and millet) used for animal feed, beer, whiskey, and other industrial products. Potato and bananas are also starchy food but they not used for baked products. In many countries, fresh and dried cassava and some other tuberous crops, consumed as starchy products. We also included soybean (Table 3.1) which comprises a considerable component of the energy source. The international price ratios between cereals (Table 3.1) characterize some preferences of the population for cereal consumption. Barley, oats, rye and triticale kernels widely used for bread baking with claims for higher concentrations of anti-oxidants and other phytochemicals with superior nutritional quality. Incorporation of such flours in bread imposes two opposite effects on the bread pricing. On one side, the whole-grain flour presumably has a lower price than the refined flour. For the wheat flour, the bran has a price of only 40% of that of the price of the refined flour thus the price of the whole-flour that is main bread component is much lower than the refined flour. On the second hand, the decrease in the dough raising quality imposes some expenses on the bread making such as an addition of baking improver such as vital gluten, increase in the proofing time and increase in the marketing expenses because of the lower-scaled bread marketing. More importantly, the superiority of these cereals in human health upon wheat products has not yet shown properly. Bread wheat shows sufficient genetic diversity to allow the development of >25,000 cultivars (Feldman et al. 1995). Such a capability to synthesize such a plethora of the biochemical compounds is presumably foundemental superiority virtue of the wheat cultivar. Such a capability enables the wheat being adapted to a wide range of environmental temperatures, humidity, soils, and all the cultivation conditions. This capability supports on the huge wheat genome, also enables the wheat to produce the plethora of the biochemical compounds, the wide range of polyphenols and other micro-ingredients, that protect the plant from pests and consists the main clue for successful breeding of the wheat. The span in the production yield (kg/ha) of the wheat is quite high even for the average yield of the world countries (1995) with the highest yield of Netherlands 8600; UK 7500; and France, Germany, Belgium 6000–7000; and the other main producers: United States 2500; Italy 3400; China 3500; Ukraine 3300; India 2400; Canda 2200; Argentina 2100; Pakistan 2000; Turkey 1900; Australia 1600; Russia 1500; and Iran 1500. In some countries such as Ecuador, Venezuela, Kazakhstan, Iraq, Algeria, and Mongolia the average yield is lower than 1000  kg/ha (Curtis 2002; Carver 2009).

The Soft and the Hard Wheat

35

The Starchy Foods Cereal list  species and sub-species, and the kernel weight (mg) (Fig. 3.2) Wheat --- spelt, emmer, farro, einkorn, Kamut, durums --- Triticum spp. (47) Rice, African rice --- Oryza spp. (20) Barley --- Hordeum spp. (45) Corn (maize) --- Zea mays (234) Rye --- Secale cereale spp. (42) Oats --- Avena spp. (34) Millets --- Brachiaria spp. (2.7) Echinochloa spp. (2.6) Sorghum --- Sorghum spp. (15) Triticale --- (30) Wild rice --- (53) Pseudocereals Amaranth --- Amaranthus caudatus (0.75) Buckwheat, Tartar Buckwheat --- (30) Quinoa --- Chenopodium quinoa Willd (2.5) Teff (tef) --- Eragrostis spp. (0.35)

The Soft and the Hard Wheat The wheat cultivars categorized as soft or hard based on their kernel texture. The main discrimination of this trait is between tetraploid species with the A and the B genomes and hexaploid species with the A, B, and D genomes. Cultivars of the tetraploid species are very hard, while those of the hexaploid species are soft. Another discrimination of the grain hardness found in different cultivars of the hexaploid T. aestivum, albeit not so distinctly as with the tetraploid/hexaploid difference. Grain hardness is an attractive breeding trait associated with different end-product properties. It has a strong effect on the milling properties, the baking quality, the flour granularity, and the starch granule integrity (the softer the grain, the less starch damage occurs). Soft wheat requires less energy to the mill, yields smaller flour particles with less starch damage and absorbs less water than the hard wheat. The hard durum wheat T. turgidum var. is mainly used for the preparation of the Italian style pasta such as macaroni, and noodles. The kernels of the various T. aestivum cultivars that have harder grains are best suited for bread, and those that are soft are best for cookies cakes and pastries. The first biochemical marker of grain softness is the friabilin, a 15-kDa marker protein. It found in high amounts on the surface of water-washed starch from soft wheat. Small amounts of the protein detected in the hard hexaploid wheat starch but were absent in the tetraploid durum wheat starch. The friabilin is a mixture of two proteins, the puroindoline A and the puroindoline

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3  The Wheat in the View of Our Whole-Menu

Fig. 3.2  The main cereal grains with the indication of the grain weight (mg)

B. These proteins are unique, among the plant proteins, as they having a cysteine-­ rich backbone and tryptophan-rich domain. The friabilin located in the starchy endosperm cells in the aleurone of the mature kernel (Nadolska-Orczyk et al. 2009). The red wheat has the most amount of gluten and used for making bread, rolls, and all-purpose flour. The soft wheat used for making flatbread, cakes, pastries, crackers, muffins, and biscuits (US Wheat Associates). Roughly 90–95% of the wheat produced in the world is the common wheat (T. aestivum), which is better known as hard wheat or soft wheat, depending on grain hardness.

The Main Wheat Classes in the US

37

The Main Wheat Classes in the US (a) Hard Red Winter – The hard red winter wheat is an ear of important, versatile bread wheat with excellent milling and baking characteristics. It has medium to high protein content (10–14%), hard endosperm, red bran, and strong and mellow gluten content. It used in artisan and pan bread, Asian noodles, hard rolls, flatbreads, and flour for general purpose. The hard red winter comprises ~40% of the wheat production in the US. (b) Hard Red Spring – The spring wheat is an ear of important bread wheat with excellent milling and baking characteristics. It has high protein content (12– 15%), hard endosperm, red bran, strong gluten, and high water absorption. It used in pan bread, hearth bread, rolls, croissants, bagels, hamburger buns, pizza crust, and for blending. The hard red spring comprises ~27% of the US production. (c) Soft Red Winter – Soft red winter wheat is an ear of high-yielding wheat with low protein content (8.5–10.5%), soft endosperm, red bran, and weak gluten. It used in pastries, cakes, cookies, crackers, pretzels, flatbread, and blending flours. This class of wheat grown primarily in the eastern third of the US and comprises ~18% of the US production. (d) Durum – Durum wheat is the hardest of all wheat classes with a high protein content (12–15%), yellow endosperm, and white bran. It used in pasta, couscous, and some Mediterranean bread. The Durum wheat comprises 4% of the US production. (e) Hard White  – Hard white wheat has a hard endosperm, white bran, and a medium to high protein content (10–14%). It used in instant/ramen noodles, whole-wheat or high extraction flour applications, Artisan and pan bread, and flatbread. The hard white wheat comprises 1% of the US production. (f) Soft White – Soft white wheat has low-protein (8.5–10.5%) and low moisture and provides excellent milling results. It used in flatbread, cakes, biscuits, pastries, crackers, udon-style noodles, and snack foods. The last two items comprise 10% of US production. Various wheat classes have not the same commercial values and differ remarkably in their commercial values. The relative prices received by the American farmers and the relative production have a wide range of relative price of 0.86–1.16 shown excluding the durum with a ratio of 1.52 (Table 3.3). Thus, the American consumer is willing to pay for durum cereal a price higher by 76% than for the hard red winter wheat presumably with no advantage in health quality. The grain hardness is determined by the way the components packed in the endosperm and measured by the resistance to fracture. The grain hardness is a grain quality trait associated with the milling properties of wheat and with the baking quality of the resulting milling products. Native starch, which is the main component of the wheat grain (70–75%), shows comparatively low influence on the functional properties of the wheat flours used in bread, cookie, and cake making. The gluten, comprising roughly 78–85% of the total protein of the wheat endosperm, is

38 Table 3.3  Relative prices received by the farmers in the US. 2016/7. (USDA, Wheat Outlook)

3  The Wheat in the View of Our Whole-Menu Relative price All wheat 1  Hard red winter 0.86  Soft red winter 1.03  Durum 1.52  White 1.05  Winter 0.91  Other spring 1.16

Relative production quantity 1 0.35 0.05 0.31 0.49

responsible for most of the viscoelastic properties of wheat flour dough. The gluten is the main factor dictating the use of a wheat variety in the bread and the pasta making. Roughly, 95% of the wheat utilized mainly as flour (whole-or refined grain) for the production of a large variety of the leavened and the flatbreads, and for the manufacture of a wide variety of other baking products. The remaining 5% is durum wheat, used for making pasta and other semolina (coarse flour) products (FAOSTAT).

The Common Wheat Products Many different food products made from the wheat flour, the particulate material obtained by the milling wheat kernels. Differences in the endosperm texture affect the properties and the quality of the flour and the preferential use. The flour characteristics such as the particle size and the damaged starch level determine its suitability for the specific end-product. Another major difference between cultivars indirectly related to the hardness is the protein quantity and quality. Generally, soft wheat cultivars bred to contain less protein than hard wheat, ~8–11% versus 10–14% protein, respectively. The hard wheat cultivars selected for high water absorption and thicker endosperm cell walls. In general, the wheat flour classified for various products according to the protein content, (%): cakes and pastries (6–8.5), cookies and some noodles (8–10), crackers and noodles (9.5–12), French-bred and flatbread (10.5–14), tin bread, some health bread and some noodles (12.5–15). Generally, the higher the protein content the higher the loaf volume with an increase of 61% in loaf volume with an increase of 5% protein content of the flour from 9% to 14%. In the noodle production, there are no strict requirements concerning the hardness of the used cultivars (Bushuk 1988). The bread-making starts with mixing flour, water, yeast (Saccharomyces cerevisiae), salt, and sometimes other minor ingredients into the dough, which then undergoes fermentation, proofing, and baking. The quality of flour, the main ingredient in the bread recipe, largely affects the bread quality. Next, to a large loaf volume, consumers appreciate a fine and homogeneous crumb structure and a pleasant mouthfeel (namely “soft”) (Pauly et al. 2013).

The Anatomy and the Ingredients of the Wheat Kernel

39

The Anatomy and the Ingredients of the Wheat Kernel Grasses produce single-seeded fruits, each formed from a single carpel with no special method of opening to liberate the seed. Botanically this fruit type is known as a caryopsis. The embryo and the endosperm both are the products of fertilization, surrounded by adherent seed coats and the pericarp tissues that formerly made up the carpel wall. The caryopses of the cereals may unambiguously call grains but the terms berry and kernel, which are often applied, specifically describe other types of the fruit. They can thus cause confusion and best avoided. Although the components of cereal grains are adapted differently among the cereal species, a generalized structure can describe for all cereals. Shape, size, and mass are the most readily identifiable characteristics of the fruits of the individual grains. Thousand-grain weight ranges between 0.14 g for teff, to 600 g for corn. In rice, the ratio of length to breadth is a useful guide to the nature of the endosperm, and more significantly the starch type present in the kernel. Shorter grains tend to be associated with stickier cooking quality. The corn grains vary from the near-spherical popcorn to flattened and angular flint corn. A depression on the distal preface arising through contraction of the endosperm is characteristic of dent corn and reflects the presence of a region of soft endosperm within a harder textured cup. The caryopses of the members of the tribes Triticeae (wheat, rye, barley, and triticale) and Avenue (oats) can be distinguished by the presence of a crease, a re-entrant region on the ventral side, that extends along the entire length of the grain, and deepest in the middle. It is most marked in the wheat (e.g. Triticum aestivum L. and other species e.g. T. durum, T. compactum), followed by triticale (Triticosecale ssp Wittmack), rye (Secale cereale L.), barley (Hordeum vulgare L.) and oats (Avena sativa L.). In milling to produce white flour, the crease presents the greatest difficulty for separation of starchy endosperm from other tissues. The main ingredients in various cereals are similar in their composition with a higher dietary fiber in barley, rye and triticale and lower content of dietary fiber in rice and corn. The differences in the composition of the major constituents between cereals (Table 3.4) have only a minor effect on the cereal quality while the main differences embedded in the minor compounds, which are responsible for the baking qualities for the bread production, the bread taste and for the nutritious qualities of the bread consumption. The first remarkable wheat bran characteristic is its ability to absorb considerable amounts of water. Water-binding mechanisms on macro-, micro-, and nanoscale, and on a molecular level allow the bran to retain water either weakly or strongly (Hemdane et al. 2016). The water retention by the bran on a macroscale ascribed to the filling of void spaces in between the bran particles, which arise from the random stacking of the bran particles. On a microscale, the pericarp which contains empty cells is spacing in between the tissue layers provides sites for the water retention. Concerning the water-binding on a nanoscale, the capillary mechanisms are involved. Nanopores in the bran can found, for instance, in the cell wall matrix as they are known to consist

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3  The Wheat in the View of Our Whole-Menu

Table 3.4  The cereal major ingredients

Wheat Triticale Barley Rye Rice, brown Corn Millet Oats Sorghum Teff

Dietary fiber % of dry matter 12.2 14.6 17.3 15.1 3.5 7.3 8.5 10.6 6.3 4.5

Protein

Fat

Ash

10.6 13.2 11.0 8.7 7.3 9.8 11.5 9.3 8.3 11

1.9 1.7 3.4 1.5 2.2 4.9 4.7 5.9 3.9 2.5

1.4 2.1 1.9 1.8 1.4 1.4 1.5 2.3 2.6 2.8

FAO et al. (1999)

of nanoporous structures. Besides, the cellulose present within this matrix also contains nanopores because of its specific structure. The bran is rich in polysaccharides that can bind water on a molecular level through the formation of hydrogen bridges. These mechanisms contribute to the water uptake by the bran in the case of unconstrained hydration. With regard to the bread making, however, hydration of the bran occurs during mixing where bran exposed to the kneading forces and hygroscopic-­ like forces exerted by the various flour constituents. Therefore, stacking phenomena and micropores do not contribute to hydration since water-bound through these mechanisms relatively weakly bound and released in the presence of these external forces. No changes in the farinograph absorption observed as a function of the average particle size. The farinograph is a device used by the baker to measure: water absorption; dough viscosity; the tolerance of the gluten flour, including peak water to gluten ratio prior to the gluten breakdown; peak mixing time to arrive at the desired water/gluten ratio; and the stability of the flour under mixing. The detrimental effects of the bran on the bread-making to bran-water interactions based on the observation that the bread loaf volumes increased when adding 2% extra water compared to the level of the water indicated by the mixograph absorption. It should note that the different aspects of the hydration behavior of the bran may relevance throughout bread-making given the dynamic conditions of the process. For instance, during the kneading, the bran can envisage absorbing only strongly bound water due to the presence of external stress. When this external stress disappears at the end of the mixing, the bran might tend to bind water, which could not bound during the mixing (Hemdane et al. 2016). The fibers typically bind water, depending on their size. The water either absorbed directly or adsorbs via the capillary forces. No effects found related to the composition of the fiber fractions. The water absorption increased in all cases when part of the flour replaced by the fiber fractions. This expected since fibers typically bind more water compared to the other main components of the flour (Noort et al. 2010).

References

41

The bran altered product water status at all structural levels (from the molecular to the macroscopic), reduced loaf volume and increased crumb hardness. During storage, the crust moisture content increased and the crumb moisture content decreased in all samples because of the macroscopic migration of the water from the water crumb to the drier crust. However, a smaller moisture content change observed in the crumb than in the crust, probably because only the water molecules from the closed portion of the crumb could migrate in the considered storage period (Curti et al. 2015). The coarse bran (720 μm, ~23 mesh) produced a higher fecal bulking and a shorter mean transit time than did the fine (180 μm, 80 mesh) bran, probably due to the higher water holding capacity of the coarse wheat bran but no differences observed in the fecal bulking (Rosa-Sibakov et al. 2015).

References Bushuk W (1988) Wheat breeding for end-product use. Euphytica 100(137–145):203–211. https:// doi.org/10.1007/978-94-011-4896-2_27 Carver BF (ed) (2009) Wheat science and trade. Wiley-Blackwell, Ames, Iowa. https://onlinelibrary.wiley.com/doi/book/10.1002/9780813818832. Curti E, Carini E, Tribuzio G, Vittadini E (2015) Effect of bran on bread staling: physico-­chemical characterization and molecular mobility. J Cereal Sci 65:25–30. https://doi.org/10.1016/j. jcs.2015.06.002 Curtis BC (2002) Wheat in the world. In: Curtis BC, Rajaram S, Macpherson HG (eds) Bread wheat: FAO plant production and protection Series. FAO, Rome. http://www.fao.org/3/y4011e/ y4011e00.htm Drewnowski A (2004) The cost of US foods as related to their nutritive value. Am J Clin Nutr 92:1181–1188. https://doi.org/10.3945/ajcn.2010.29300.1 Dutcher RA (1917) Shall we eat whole-wheat bread? Science 47:228–232 Ezzati M, Riboli E (2013) Behavioral and dietary risk factors for noncommunicable diseases. NEJM 369:954–964. https://doi.org/10.1056/NEJMra1203528 FAO, Haard NF, Odunfa SA, Lee CH, Quintero-Ramírez R, Lorence-Quiñones A, Wacher-Radarte C (eds.) (1999) Agricultural services bulletin no 138. http://www.fao.org/docrep/x2184e/ x2184e04.htm FAOSTAT. http://www.fao.org/faostat/en/#home Fardet A, Boirie Y (2014) Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews. Nutr Rev 72:741–762. https://doi.org/10.1111/nure.12153 Feldman M, Lupton FGH, Miller TE (1995) Chap 39: Wheats. In: Group (pp. 184–195). London. Goren-Inbar N, Alperson N, Kislev ME, Simchoni O, Melamed Y, Ben-Nun A, Werker E (2004) Evidence of Hominin control of fire at Gesher Benot Ya’aqov. Israel Sci 304:725–727. https:// doi.org/10.1126/science.1095443 Hardy K, Brand-Miller J, Brown KD, Thomas MG, Copeland L (2015) The importance of dietary carbohydrate in human evolution. Q Rev Biol 90:251–268 Hemdane S, Jacobs PJ, Dornez E, Verspreet J, Delcour JA, Courtin CM (2016) Wheat (Triticum aestivum L.) bran in bread making: a critical review. Compr Rev Food Sci Food Saf 15:28–42. https://doi.org/10.1111/1541-4337.12176 Hung PV (2016) Phenolic compounds of cereals and their antioxidant capacity. Crit Rev Food Sci Nutr 56:25–35. https://doi.org/10.1080/10408398.2012.708909

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Imamura F, Micha R, Khatibzadeh S, Fahimi S, Shi P, Powles J, Mozaffarian D (2015) Burden of diseases nutrition and chronic diseases expert group (NutriCoDE). Dietary quality among men and women in 187 countries in 1990 and 2010: a systematic assessment. Lancet Glob Health 3:e132–142 Supp. www.thelancet.com/lancetgh Index Mundi. http://www.indexmundi.com/agriculture/?commodity=wheat&graph=imphorts Kaur KD, Jha A, Sabikhi L, Singh AK (2014) Significance of coarse cereals in health and nutrition: a review. J Food Sci Technol 51:1429–1441. https://doi.org/10.1007/s13197-011-0612-9 Kislev ME, Weiss E, Hartmann A (2004) Impetus for sowing and the beginning of agriculture: ground collecting of wild cereals. Proc Natl Acad Sci 101:2692–2695. https://doi.org/10.1073/ pnas.0308739101 Kontis V, Mathers CD, Rehm J, Stevens GA, Shield KD, Bonita R, Riley LM, Poznyak V, Beaglehole R, Ezzati M (2014) Contribution of six risk factors to achieving the 25X25 non-­ communicable disease mortality reduction target: a modelling study. Lancet 384:427–437. https://doi.org/10.1016/S0140-6736(14)60616-4 Kontis V, Mathers CD, Bonita R, Stevens GA, Rehm J, Shield KD, Riley LM, Poznyak V, Jabbour S, Garg RM, Hennis A, Fouad HM, Beaglehole R, Ezzati M (2015) Regional contributions of six preventable risk factors to achieving the 25 × 25 non-communicable disease mortality reduction target: a modelling study. Lancet Glob Health 3:e746–e757. https://doi.org/10.1016/ S2214-109X(15)00179-5 Micha R, Khatibzadeh S, Shi P, Andrews KG, Engell RE, Mozaffarian D (2015) Global, regional and national consumption of major food groups in 1990 and 2010: a systematic analysis including 266 country-specific nutrition surveys worldwide. BMJ Open 5:e008705. https://doi. org/10.1136/bmjopen-2015-008705 Nadolska-Orczyk A, Gasparis S, Orczyk W (2009) The determinants of grain texture in cereals. J Appl Genet 50:185–197. https://doi.org/10.1007/BF03195672 Noort MWJ, Haaster DV, Hemery Y, Schols HA, Hamer RJ (2010) The effect of particle size of wheat bran fractions on bread quality  – evidence for fibre-protein interactions. J Cereal Sci 52:59–64. https://doi.org/10.1016/j.jcs.2010.03.003 Onipe OO, Jideani AIO, Beswa D (2015) Composition and functionality of wheat bran and its application in some cereal food products. Int J Food Sci Technol 50:2509–2518. https://doi. org/10.1111/ijfs.12935 Pauly A, Pareyt B, Fierens E, Delcour JA (2013) Wheat (Triticum aestivum L. and T. turgidum L. ssp. durum) kernel hardness: II. Implications for end-product quality and role of puroindolines therein. Compr Rev Food Sci Food Saf 12:427–438. https://doi.org/10.1111/1541-4337.12018 Peña RJ (2002) Wheat for bread and other foods. In: Curtis BC, Rajaram S, Gómez Macpherson H (eds) Bread wheat, improvement and production. FAO, Rome. http://www.fao.org/3/Y4011E/ y4011e00.htm#Contents Rosa-Sibakov N, Poutanen K, Micard V (2015) How does wheat grain, bran and aleurone structure impact their nutritional and technological properties? Tr Food Sci Technol 41:118–134. https:// doi.org/10.1016/j.tifs.2014.10.003 Shewry PR (2009) Wheat. J Exp Botany 60:1537–1553. https://doi.org/10.1093/jxb/erp058 US Wheat Associates. https://www.uswheat.org/ USDA, Wheat Outlook. https://www.ers.usda.gov/webdocs/publications/85131/whs-17i. pdf?v=42992; http://www.agmrc.org/commodities-products/grains-oilseeds/wheat Weiss E, Wetterstrom W, Nadel D, Bar-Yosef O (2004) The broad spectrum revisited: evidence from plant remains. Proc Natl Acad Sci 101:9551–9555. https://doi.org/10.1073/pnas.0402362101 Wheat Data USDA, United States Department of Agriculture. Economic research service. http:// www.ers.usda.gov/data-products/wheat-data.aspx#25184 Wikipedia. https://www.wikipedia.org/

Chapter 4

The Milling and the Refining

The milling technique of the whole-wheat flour is one of the most sensitive procedures along the whole-line of the whole-wheat bread production for the preservation of the bread nutritious quality. Along all the stages of bread production of Ploughing, Sowing, Cultivating, Fertilizing, Harvesting, Transportation and Storage, Milling, Dough preparation, Baking, Bread Slicing, and Marketing, the aggressive milling might severely deteriorate the bread quality. The dietary fiber and a high concentration of the bioactive components with antioxidant properties are the main unique ingredients of the whole-bread. However, a substantial part of the bioactive components is tightly bound to the dietary fiber. The kernel milling increases the detected concentration of the total antioxidant capacity and other compounds. At some range, the higher the milling intensity the higher the detected compounds observed such as polyphenols, methyl donors, vitamins, tocols, and the yellow pigments. With the highest milling intensity, the instantaneous high temperature of the milling friction destructs some part of the kernel proteins, the unsaturated fatty acid, and the bioactive components. The higher milling intensity required to obtain small particles of the wheat flour for the higher dough rising and better baking quality.

The Milling The approximate cost-price breakdown of the flour production is as follows of the total cost: the grain ~81%, electricity 6.5%, labor 4%, and expendable materials and other costs 8.5%. Like the grain trade, the wheat milling is a thin margin business. On the one hand, wheat millers depend on the wheat markets that determine the raw material cost. On the other hand, they depend on the preferences and the willingness

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_4

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4  The Milling and the Refining

to pay off their consumers for the flour they produce. The ability of the wheat millers to hedge the price risks is often limited due to the lack of the grain futures markets or poor contract enforcement in the spot grain and the flour markets in the transition countries. The millers in the private sector in many countries may be subject to government regulation as flour and bread considered socially important food products. In this case, governments may regulate the wheat milling business through administrative price-fixing, an establishment of maximum margins or provision of input subsidies. Depending on the output ratios, the wheat flour may contribute 93% to the gross margin generated in the wheat milling, while the wheat bran may contribute 7%. These contribution ratios change depending on the flour and feed demand and prices (Agribusiness Handbook, FAO 2009). The whole-wheat flour produced by a variety of milling techniques. The result is flours with widely different particle size and functionalities. Perhaps the most important consideration in producing the whole-grain flour is selecting the milling process that will use. Indeed, the milling technique may have a greater impact on the quality of wheat used for the producing of the whole-wheat bread than the formulation of the bread itself. The 2 predominant techniques for the milling of the whole-­ grain flours are the roller mills and the plate mill. The whole-grain flours could also be produced with a hammer mill or a stone mill but these are rarely used. Right after the milling, the flour proteins contain a high proportion of sulfhydryl groups that exhibit poor quality for bread making. Short-term (months) aging or the chemical bleaching improves flour functionality through sulfhydryl/disulfide interchange among the gluten proteins (Doblado-Maldonado et al. 2012). Querns and other milling devices are the main pillars of the agricultural culture found in the ancient civilizations all over the world. Sifting and separate millstream is modern phenomena. In stone milling, kernel crushed between the stationary stone and the stone that rolls and presses the kernel. During the Roman era, the bread baked from unrefined flour thought to suitable only for the lower classes, slaves, and gladiators. During the first century, the bread made from sifted flour produced on a large commercial scale throughout much of the Roman world. Until the Industrial Revolution, the wheat-flour refined at a limited scale. With power availability, the refined-flour was highly widespread (Jones et al. 2015). The late 19th and early 20th centuries in the West saw great changes in the milling processes, from stone milling using water or wind power, to increasingly sophisticated roller milling, with an increasing loss of fiber and the accompanying ingredients in the process. In the 1970s and onwards there was an enhanced interest in possible diseases which could be related to the loss of the fiber in the diet. The milling has different effects on the bran and the germ. In the case of the wheat, the two come apart separately. They can separate by sieving and be stable for some period without further treatment. In the case of the corn and rice, the bran and the germ come away together and the resultant bruising releases the lipases that interact with the oil content leading, if left untreated, to the early rancidity of the combined germ and bran. Thus, whole-meal wheat flour has a stable shelf life for a variable period time, but the only satisfactory way to eat whole-maize is either on the cob or home-pounded and cooked on the same day. The rice can only be eaten in the unrefined state as brown or the un-milled

The Milling

45

rice. The milled rice undergoes changes during storage. During the rice milling, some of the lipase present in the bran enters the endosperm and as the rice stored it reacts with a small amount of the oil present in the rice grain (Tovey 2015). The inner and the outer pericarps contain empty cells, with cell walls mostly made of ~46% arabinoxylan with a high degree of branching, with about 25% cellulose and lignin. The cell wall contains also dimers of ferulic acid (2.5 mg/g) with cross-linking polysaccharides. The seed coat (or testa) is very rich in alkylresorcinols. The hyaline layer (outside the aleurone layer) is mainly composed of arabinoxylan and very rich in monomeric ferulic acids. The intracellular aleurone space, characterized by the high content of the small vacuoles, and proteins, minerals, phytates, lipids, vitamins, and anti-oxidants. The aleurone cell wall is mainly composed of arabinoxylan, β-glucans, and proteins. The aleurone phenolic compounds are highly esterified with arabinoxylan. The most common milling technology involves the dry process, which can efficiently reduce the median particle size of the wheat bran from 1000 μm (18 mesh) down to 30–35 μm (456 mesh). The anti-oxidant capacity is an important feature in defining the nutritional and the technical quality of the wheat fractions and is affected by the particle size. The anti-oxidant capacity of the whole-wheat grain, bran and aleurone fractions could increase up to 2-fold through intensive milling. The greater the anti-oxidant capacity of the ultra-fine ground bran and aleurone fractions found positively correlate with their specific surface, which allowed a greater exposure of the anti-oxidant phenolic moieties without the release of the phenolic moieties (Rosa-Sibakov et al. 2015). The heat generated during the milling process due to friction within the equipment and to the deformation of the material in the elastic range. The temperature increase is particularly important when high operation speeds are applied. This temperature increase may affect the quality of the product being processed (Beirão and Alves 2014). Because of these 2 opposite trends of the increase and the decrease in the anti-oxidant capacity, the collected data for the effect of milling on the antioxidant is not conclusive and most limited. Wheat grain processed by roller milling that produces millstreams with distinct functional characteristics. These functional characteristics are dependent on several factors including but not limited to the wheat cultivar, the kernel hardness, tempering conditions, and the mill settings. The break and the early reduction of the millstreams primarily composed of pure and starchy endosperm. Later reduction streams tend to have higher ash content due to the bran presence. The concentration of the protein and ash increases as the extraction rate increases. To produce a commercial flour, selected millstreams with similar functional characteristics combined to produce flour blends destined for a particular end-user; blends can produce a wide range of flour grades. The flour grades include high purity blends (low ash) such as fancy patent, first patent, and short patent as well as lower purity (high ash) blends like fancy clear and first clear. The flour stream blending based on the desired characteristics needed to produce a certain product. The blending process can benefit from a greater understanding of the functional characteristics of each flour stream. Further, a more optimal blending

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of functional flour fractions may eliminate or reduce the need for further treatments and hence decrease the labeling requirements. One minor constituent that significantly affects the functional characteristics of the flours is the arabinoxylans. The arabinoxylans are non-starch polysaccharides that comprise ~2–6% of the wheat kernel. These polymers are structural components of the cell walls; they form a matrix with the protein to entrap cellulosic material as well as glucomannans. Similar to the protein and the ash the arabinoxylans not uniformly distributed in the wheat kernel. Arabinoxylans are more highly concentrated in the bran, pericarp, seed coat, and the aleurone layers. The concentration of the arabinoxylans in the central endosperm significantly less compared to the outer layers of the wheat kernel. Furthermore, the arabinoxylans are also not homogeneous in the physical conformation (Ramseyer et al. 2011). Enzymes, such as peroxidases, polyphenol oxidases, and amylases of the aleurone layer liberated from the tissues during the milling, leading to off-flavor development, pigment darkening, and starch breakdown. The type of milling technique has shown to have a greater impact on the sensory quality of whole-grain wheat bread than the baking technique. The bread baked with roller-milled wheat described as being sweet, juicy, and compact, with a small slice area, whereas bread baked with stone-milled wheat was salty, deformed, and roasted. Efficient separation of the pericarp from the starchy endosperm depends on the structural integrity of the pericarp and the milling process used. The flavor components unevenly distributed in the kernel, and thus the choice of suitable milling fractions is one option for the production of flours rich in dietary fiber but mild in taste (Heiniö et al. 2016).

The Kernel Hardness Wheat typically divided into hard and soft classes. The grain hardness in the wheat is also the main determinant of the end-product quality. The soft wheat requires less energy. The mill yields smaller flour particles with less starch damage and absorbs less water compared to the hard wheat. The soft wheat has softer endosperm texture that mills easily, so needs less energy to mill, produces smaller particles, and a small amount of starch damaged after milling as compared to hard wheat. Soft texture results from the higher level of friabilin whereas hard texture results from the low level of friabilin on starch granule surface. Soft wheat generally used to make cookies and pastries while hard wheat typically used to make bread. Friabilin could use as a marker protein for the grain hardness. The friabilin is an abundant 15 kDa protein on water-washed starch granules from soft wheat, and that little to no friabilin is found on water-washed starch granules from the hard wheat. The friabilin composed mainly of 2 proteins, puroindoline A and puroindoline B. These proteins contain a unique tryptophan-rich domain that involved in the binding of the phospholipids on the surface of the starch granules. The ‘soft type’ lines have increased levels of friabilin, decreased grain hardness, and starch granules that resembled those indicative of the soft wheat. The baked products in their several forms are the result of its

The Milling

47

unique seed storage proteins that produce the gluten upon hydration and mixing. The variation in the grain hardness determines its applications. Wheat grain quality determines the market value based on the features of the kernel texture. End-use baking products and the quality influenced by the protein content in specific products, such as biscuits, pan bread, noodles, and chapattis. The quality characters include the dough extensibility and its development time, the extreme dough resistance, the water absorption and the most important milling yield (Hogg et al. 2004; Iftikhar and Ali 2017). The cakes and the cookies production need flour of the softer kernel and with an increasing order: crackers, noodles, bread, and pasta with a need for the harder kernels (Pauly et al. 2013).

The Jet Milling The jet milling does not use uniform and standardized devices. The common features of all the devices for the jet milling that they revolve at a high velocity and emit very high and instantaneous temperatures that affect the delicate compounds of the wheat kernel. Unfortunately, no standard methodology has accepted, and either has not suggested for the comparative definition of the nutritional qualities of the milled products. Everyone, of the devices used for the jet milling, has its own specific effects, and with different effects while changing velocities. The jet milling is an alternative process for the common rolling device to reduce the whole-wheat flour particle size. It is a fluid energy impact milling technique commonly used to produce particle sizes of 85 °C are regularly measured. However,

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such a temperature does not measure at the touching edge of the kernel and the metal thus some instantaneous temperatures may rise tremendously to >600 °C. The observed temperature of the flour stream does not mirror the instantaneous high temperature.

 he Destruction of the Precious Nutritional T and the Vulnerable Ingredients of the Whole-Wheat An only small part of the kernel starch undergoes deformation during the milling procedure for the production of the refined flour. Concomitantly, small amounts of the vulnerable and micro compounds destroyed because of the efficient milling with the low energy and the low content of the micro compounds. However, with the milling step for the whole-wheat bread, a major pitfall is foreseen. Because of the requirement for the high mesh flour, the bran part of the kernel must undergo an extensive crushing. The high mesh flour with the fine particles required to maintain the delicate bread structure and to reduce the destructing of the carbon dioxide bubbles in the dough produced by the fermentation. The intensive milling destroys some minor ingredients and more importantly some micronutrients in the whole-­ wheat flour. By using the roller-mill, the crushed kernels passing through many stages of crushing and refining. To get the whole-meal by the rolling mill technique, all the flour streams are mixed together into one stream to produce the whole-wheat flour that contains the original kernel composition. By using the high-velocity machinery (plate, disk, or jet mills) the whole-wheat flour produced by a one-step operation. With the stone mill, a similar kernel crushing occurred. Table 4.6  The destruction of the vulnerable ingredients by the milling and the increase in the starch damage

Lysine Histidine Valine Linolenic acid Starch damage Flour stream temperature, Ca

Milling machinery Roller Plate/disc Hammer Relative damage and decrease, % 100 71 58 100 51 58 100 54 54 100 57 74 100 213 137 32° 78° 50°

Stone 48 48 51 33 235 85°

Prabhasankar and Rao (2001) a On the vigorous milling operation, the instantaneous temperature on the contact between the grain and the blade or the stone, might escalate to hundreds of degrees and more. The temperature of the flour streams does not mirror the instantaneous temperature (Malkin and Guo 2007; Hou and Komanduri 2004)

References

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Such an operation distracts some of the minor flour ingredients such as: (a) Some amino acids in the wheat proteins as lysine, histidine, and valine. (b) Unsaturated lipids and in particular the linolenic acid. (c) Vitamins. (d) A long list of polyphenols and other delicate ingredients. Whenever such destruction measured, robust information collected but the number of the studies is most limited. Some of the information gathered from aggressive milling of other grains. The deformation and the destruction produced by milling operation were shown in 4 milling devices (Table 4.6): (a) Roller mill that is the most widespread device that operates with the lowest energy consumption and at the highest efficiency; (b) Plate- or the disc- mill that operates with high-energy consumption and with the lowest energy efficiency; (c) Hammer-mill; (d) Stone-mill. (Prabhasankar and Rao 2001) Presently, the last two devices are less used commercially. The instantaneous high temperature occurred on the aggressive milling destroys some of the vulnerable ingredients of the wheat kernel. Such destruction mirrors the destruction of many other nutritional precious ingredients such as polyphenols, vitamins, other tocopherols and carotenoids, methyl donors, sterols, and stanols, flavonoids, lignans, and other anti-oxidant ingredients. The extent of the starch deformation that occasionally measured might represents the scale of the destruction of the other ingredients. Because of the concentrations of all of these micro-ingredients are lower by 3–50 fold than their content in the whole-flour, the destruction effect in the refined flour has a lower impact (Adom et al. 2005).

References Adom KK, Sorrells ME, Rui HL (2005) Phytochemicals and antioxidant activity of milled fractions of different wheat varieties. J Agric Food Chem 53:2297–2306. https://doi.org/10.1021/ jf048456d Agribusiness Handbook, FAO (2009). http://www.fao.org/3/i1002e/i1002e00.htm Aprodu I, Banu I (2012) Antioxidant properties of wheat mill streams. J Cereal Sci 56:189–195. https://doi.org/10.1016/j.jcs.2012.05.005 Beirão S, Alves VD (2014) Dry milling. In: Guine RDPF, Correia PMDR (eds) Engineering aspects of cereal and cereal-based products. CRC, Boca Raton, pp 97–116 Delcour JA, Bruneel C, Derde LJ, Gomand SV, Pareyt B, Putseys JA, Wilderjans E, Lamberts L (2010) Fate of starch in food processing: from raw materials to final food products. Annu Rev Food Sci Technol 1:87–111. https://doi.org/10.1146/annurev.food.102308.124211

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Dewettinck K, Bockstaele FV, Kühne B, Walle DVD, Courtens TM, Gellynck X (2008) Nutritional value of bread: influence of processing, food interaction and consumer perception. J Cereal Sci 48:243–257. https://doi.org/10.1016/j.jcs.2008.01.003 Doblado-Maldonado AF, Pike OA, Sweley JC, Rose DJ (2012) Key issues and challenges in whole-wheat flour milling and storage. J Cereal Sci 56:119–126. https://doi.org/10.1016/j. jcs.2012.02.015 Frølich W, Åman P, Tetens I (2013) Whole-grain foods and health - a Scandinavian perspective. Food Nutr Res 57:18503. https://doi.org/10.3402/fnr.v57i0.18503 Gebruers K, Dornez E, Boros D, Fraś A, Dynkowska W, Bedo Z, Rakszegi M, Delcour JA, Courtin CM (2008) Variation in the content of dietary fiber and components there of in wheats in the healthgrain diversity screen. J Agric Food Chem 56:9740–9749. https://doi.org/10.1021/ jf800975w Heiniö RL, Noort MWJ, Katina K, Alam SA, Sozer N, Kock HLD, Hersleth M, Poutanen K (2016) Sensory characteristics of wholegrain and bran-rich cereal foods - a review. Trends Food Sci Technol 47:25–38. https://doi.org/10.1016/j.tifs.2015.11.002 HMDB. http://www.hmdb.ca/hml Hogg AC, Sripo T, Beecher B, Martin JM, Giroux MJ (2004) Wheat puroindolines interact to form friabilin and control wheat grain hardness. Theor Appl Genet 108:1089–1097. https://doi. org/10.1007/s00122-003-1518-3 Hou ZB, Komanduri R (2004) On the mechanics of the grinding process, part III  - thermal analysis of the abrasive cut-off operation. Int J Mach Tools Manuf 44:271–289. https://doi. org/10.1016/j.ijmachtools.2003.09.009 Iftikhar A, Ali I (2017) Kernel softness in wheat is determined by starch granule bound puroindoline proteins. J Plant Biochem Biotechnol 26:247–262. https://doi.org/10.1007/s13562-016-0387-1 Jakobi S, Jekle M, Becker T (2018) Direct link between specific structural levels of starch and hydration properties. Carbohydr Polym 181:159–166. https://doi.org/10.1016/j.carbpol.2017.10.062 Jones JM, Adams J, Harriman C, Miller C, Kamp JWVD (2015) Nutritional impacts of different whole-grain milling techniques: a review of milling practices and existing data. Cereal Foods World 60:130–139. https://doi.org/10.1094/CFW-60-3-0130 Lazaridou A, Vouris DG, Zoumpoulakis P, Biliaderis CG (2018) Physicochemical properties of jet milled wheat flours and doughs. Food Hydrocoll 80:111–121. https://doi.org/10.1016/j. foodhyd.2018.01.044 Liu F, He C, Wang L, Wang M (2018) Effect of milling method on the chemical composition and antioxidant capacity of Tartary buckwheat flour. Int J Food Sci Technol 53:2457–2464. https:// doi.org/10.1111/ijfs.13837 Lu Y, Luthria D, Fuerst EP, Kiszonas AM, Yu L, Morris CF (2014) Effect of processing on phenolic composition of dough and bread fractions made from refined and whole-wheat flour of three wheat varieties. J Agric Food Chem 62:10431–10436. https://doi.org/10.1021/ jf501941r Lu Y, Fuerst EP, Lv J, Morris CF, Yu L, Fletcher A, Kiszonas AM, Yu L, Luthria D (2015) Phytochemical profile and antiproliferative activity of dough and bread fractions made from refined and whole-wheat flours. Cereal Chem 92:271–277. https://doi.org/10.1094/ CCHEM-10-14-0214-R Malkin S, Guo C (2007) Thermal analysis of grinding. Ann CIRP 56:760–782. https://doi. org/10.1016/j.cirp.2007.10.005 Moore J, Luther M, Cheng Z, Yu L (2009) Effects of baking conditions, dough fermentation, and bran particle size on antioxidant properties of whole-wheat pizza crusts. J Agric Food Chem 57:832–839. https://doi.org/10.1021/jf802083x Pauly A, Pareyt B, Fierens E, Delcour JA (2013) Wheat (Triticum aestivum L. and T. turgidum L. ssp. durum) kernel hardness: II. Implications for end-product quality and role of puroindolines therein. Compr Rev Food Sci Food Saf 12:427–438. https://doi.org/10.1111/1541-4337.12018 Prabhasankar P, Rao PH (2001) Effect of different milling methods on chemical composition of whole-wheat flour. Eur Food Res Technol 213:465–469. https://doi.org/10.1007/ s002170100407

References

63

Protonotariou S, Drakos A, Evageliou V, Ritzoulis C, Mandala I (2014) Sieving fractionation and jet mill micronization affect the functional properties of wheat flour. J Food Eng 134:24–29. https://doi.org/10.1016/j.jfoodeng.2014.02.008 Protonotariou S, Mandala I, Rosell CM (2015) Jet milling effect on functionality, quality and in vitro digestibility of whole wheat flour and bread. Food Bioprocess Technol 8:1319–1329. doi: 10.1007/s11947-015-1494-z Ragaee S, Seetharaman K, Abdel-Aal ESM (2014) The impact of milling and thermal processing on phenolic compounds in cereal grains. Crit Rev Food Sci Nutr 54:837–849. https://doi.org/1 0.1080/10408398.2011.610906 Ramseyer DD, Bettge AD, Morris CF (2011) Endogenous and enhanced oxidative cross-­ linking in wheat flour mill streams. Cereal Chem 88:217–222. https://doi.org/10.1094/ CCHEM-11-10-0158 Rosa-Sibakov N, Poutanen K, Micard V (2015) How does wheat grain, bran and aleurone structure impact their nutritional and technological properties? Trends Food Sci Technol 41:118–134. https://doi.org/10.1016/j.tifs.2014.10.003 Slavin J (2004) Whole-grains and human health. Nutr Res Rev 17:99. https://doi.org/10.1079/ NRR200374 Slavin JL, Martini MC, Jacobs DR, Marquart L (1999) Plausible mechanisms for the protectiveness of whole-grains. Am J Clin Nutr 70:459S–463S Slavin JL, Jacobs D, Marquart L (2001) Grain processing and nutrition. Crit Rev Biotechnol 21:49–66. https://doi.org/10.1080/20013891081683 Steffen LM, DRJr J, Stevens J, Shahar E, Carithers T, Folsom AR (2003) Associations of whole-­ grain, refined-grain, and fruit and vegetable consumption with risks of all-cause mortality and incident coronary artery disease and ischemic stroke: the atherosclerosis risk in communities (ARIC) study. Am J Clin Nutr 78:383–390 Tovey F (2015) Milling of wheat, maize and rice: effects on fibre and lipid content and health. World J Gastroenterol 10:1695–1696. https://doi.org/10.3748/wjg.v10.i12.1695 Wang L, Yao Y, He Z, Wang D, Liu A, Zhang Y (2013) Determination of phenolic acid concentrations in wheat flours produced at different extraction rates. J Cereal Sci 57:67–72. https://doi. org/10.1016/j.jcs.2012.09.013 Wang S, Yu J, Xin Q, Wang S, Copeland L (2017) Effects of starch damage and yeast fermentation on acrylamide formation in bread. Food Control 73:230–236. https://doi.org/10.1016/j. foodcont.2016.08.002 Yilmaz ÖM, Bakkalbaşı E, Ercan R (2018) Phenolic acid contents and antioxidant activities of wheat milling fractions and the effect of flour extraction rate on antioxidant activity of bread. J Food Biochem 42:e12637. https://doi.org/10.1111/jfbc.12637 Yu L, Nanguet AL, Beta T (2013) Comparison of antioxidant properties of refined and whole-­ wheat flour and bread. Antioxidants 2:370–383. https://doi.org/10.3390/antiox2040370

Chapter 5

The Kernel Organs and Composition

Plant cell walls composites of polysaccharides, with cellulose as a fibrous ­component and the sets of matrix polysaccharides. These matrix polysaccharides include glucans, hetero-xylans, hetero-mannans (often referred to as hemicelluloses), and pectic polysaccharides that often present in supramolecules containing a range of pectic domain. The arabinoxylan comprises 70% of total cell wall polysaccharides of the starchy endosperm in wheat. The endosperm cell walls of the grasses typically have low levels of cellulose, xyloglucan, and pectins and high contents of arabinoxylan and mixed-linkage glucan relative to the cell walls of non-Poaceae plants, although the relative amounts of the arabinoxylan and mixed-linkage glucan vary substantially between the cereal species and the different grain tissues. The arabinoxylan comprises 70% of the total cell wall polysaccharides of the starchy endosperm in the wheat and 20% of the mixed-linkage glucan. The cereal arabinoxylan has a backbone of the xylose residues that can be mono-substituted with the arabinose residues at the O-3 or di-substituted at the O-2 and O-3 positions. The degree of substitution differs between the developmental stages and between the cells at different positions within the endosperm. The variation in substitution level between mono- and di-substituted arabinoxylan thought to regulate the hydration status of the cell wall, affecting its flexibility and potential of the nutrient transfer rate. The arabinoxylan of the grasses typically esterified with ferulic acid at the 5 positions of the arabinose residues and thought to provide extra structural strength in the cell wall matrix through the ability to form ether linkages between the ferulic residues present on adjacent arabinoxylan chains. In general, the grass mixed-­ linkage glucan contains single 1,3-β-glucan linkages interspersed by 3 or 4, 1,4-β glucan linkages with the continuous stretches of up to 14 1,4 linkages being reported in the wheat bran although these are a minor component. The ratio and distribution of these 2 types of the linkage may have profound effects on the structural characteristics including the ability to form inter-chain interactions. The callose (1,3-β-glucan) has also been demonstrated as an essential component of the first anticlinal cell wall extensions during cellularization and early cell wall development © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_5

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(the cell plate deposition) where it appears as a transient component during cellularization. As already mentioned, the pectin is a minor component of the endosperm cell wall of the wheat (Palmer et al. 2014). The seed coat of the wheat kernel provides a protective layer for the developing zygote. The evolution of the sexual reproduction and the seed underlies much of the evolutionary success of the flowering plants. The most distinctive characteristic of the angiosperms is the double fertilization event, followed by the development of a seed encased in the maternal tissue, referred to as the test or the seed coat. The enclosure of the developing embryo affords it protection and thereby enhances its chances of reaching maturity and establishing the subsequent generation. The progenitor structure of the angiosperm seed on the female side is the ovary, and its final form comprises an embryo, an endosperm, and the seed coat. The embryo results from the fusion between an egg cell and a sperm nucleus, while the endosperm develops from the fusion between the 2 central cell nuclei and a 2nd sperm nucleus to produce (in diploid species) a triploid structure. The seed coat is entirely maternal in origin (Radchuk and Borisjuk 2014).

The Bran The bran is the hard outer layers of the cereal grain. It consists of the combined aleurone and the pericarp. Along with the germ, it is an integral part of the whole-­ grains, and often produced as a byproduct of the milling in the production of the refined grains. The bran consist of 4 separate layers: pericarp; testa; nucellar layers and aleurone cells. The regular wheat bran comprised of 6–23% pericarp (epidermis, hypodermis, cross, and tube cells), 6–30% seed coat and nucellar epidermis, 33–52% aleurone layer, and 9–35% starchy endosperm. When the bran removed from the grain, the grain loses a portion of its nutritional value. The bran is present in the grain and may milled from any cereal grain, including wheat, rice, corn, oats, barley, rye, and millet. The bran is not the same as chaff, which is the coarser scale material surrounding the grain but not forming part of the grain itself. The flour extraction rate ranges from 73–77%, depending on the milling process, the variety of wheat and the cultivation conditions. With the bran, the price is about 43% of that of the refined flour than the price for the whole-wheat flour is ~86% of that of the refined flour without considering some expenses for the bran milling and the market dimension that has a considerable effect on the pricing system. The total market of bran account for about 12% of the total wheat production (Onipe et al. 2015; Laddomada et al. 2015). The bran accounts for about 25% of the milling output. In contrast to refined flour, these bran-rich products are typically used for animal feed (about 90%) while only 10% used to feed humans. With such a high difference between the white flour and the bran priced the milling and the bakery industry trying to divert more bran for human food. Wheat kernel or caryopsis has 3 parts: the endosperm, the germ, the multiple histological outer layers: the outer pericarp (15–30 μm), the inner pericarp (5–10 μm), the seed coat (5–8 μm), the nucellar layer (2–3 μm) and the aleurone layer (30–60 μm),

The Bran

67

commonly denominated as the botanical bran. Different layers distinctively differ in their types of the carbohydrates and the types of the polyphenols (with the main types: ferulic acid, dehydro-dimers of ferulic acid, dehydro-­trimers of ferulic acid, p-coumaric acid, and sinapic acid). During the conventional wheat roller milling, a large part of the endosperm separated from the germ and the bran through consecutive milling, the sieving, and the purifying steps. The endosperm is further ground to the wheat flour following different degrees of refinement and traditionally used for bread making. The bran, together with the aleurone layer and the remnants of the starchy endosperm and germ, end-up in a range of milling by-products, which are recovered at different stages in the mill. The bran-rich streams distinguishable based on 2 features: the particle size and the endosperm content. The coarse bran has a low endosperm content due to the efficient removal of the endosperm from the outer kernel layers early in the milling process. The bran-­ containing side streams recovered further down the milling process typically consists of the fine bran particles and contain relatively more endosperm. Low-grade flour typically consists of the finest bran particles with dimensions that are close to the flour particles. Dependent on the mill, these side streams may offer separately or as specific mixtures. The bran itself is a complex biological material characterized by a specific histological structure and a diverse chemical composition, as well as physical properties. Regular wheat bran mainly consists of nonstarch carbohydrates with 17–33% arabinoxylan, 9–14% cellulose, 3–4% fructan and 1–3% mixed-­ linkage β-D-glucan as the major components. Besides nonstarch carbohydrates, commercial wheat bran also contains high levels of starch (6–30%), due to attachment of residual endosperm to the bran, protein (14–26%), lipids (3–4%), lignin (3–10%), minerals (5–7%), phytic acid (4.5–5.5%), phenolic acids (0.4–0.8%). These constituents distributed over the bran structure but not homogeneously. The bran price is lower by ~40% of the refined flour, thus the mixing of the bran and the refined flour produces the whole-flour with a lower price than the refined flour. Apparently, with a lower price of the main ingredient of the whole-wheat bread, such a product might have a lower price than that the refined flour bread. Actually, in many countries and presumably in all of the countries, the retail price of the whole-wheat bread is much higher than the refined flour bread. The baking of the whole-wheat bread requires some higher content of baking additives and a longer procedure of the dough rising. The extent of the bread production might have the dominant effect on the bread pricing as the whole-wheat bread distributed at much a lower scale than that of the refined wheat bread. Without the intervention of the authorities, the pricing system and the scale of the whole-wheat consumption would not change. Such an intervention opposes the liberal opinions about the price control policy imposed by the authorities but the bread issue has a unique status because of the potential remarkable effect on the national public health that justifies administrative intervention.

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On the macroscale, the water retention by the bran ascribed to the filling of void spaces in between the bran particles, which arise from the random stacking of the bran particles. On the microscale, the pericarp cells layers provide sites for water retention. With regard to the water-binding on the nanoscale, the capillary mechanisms involved. The bran is rich in the polysaccharides which can bind water on a molecular level through the formation of the hydrogen bridges. The strong tendency of the bran to absorb water resulted in the competition for water between the bran and the other key flour components like the starch and the gluten with the typical longer dough development time in the bran-rich dough and slower water uptake kinetics of the bran compared to the flour constituents (Hemdane et  al. 2016; Wikipedia).

The Germ (the Kernel Embryo) Most of the germ wheat fractionation worldwide, produced during the wheat milling is used for animal feed. With the grain maturity, it comprises substances from the developing embryo, embryonic axis (shoot, mesocotyl, and radicle) and scutellum, which considered homologous with the cotyledon. The name scutellum derives from its shield-like shape and it lies between the embryonic axis and the endosperm. The embryo contains the highest concentration of lipid and lipid-soluble vitamins in the cereal grains. It also has the highest moisture content in the mature grain. Usually, the embryo not identified as a nutritional target for the grain improvement by the breeders. The germ contains (%), lipids ~10–15, sugars ~17, fiber ~1.5–4.5, minerals ~4; and mg/kg, tocopherols 300–740, phytosterols 24–50, policosanols 10, carotenoids 4–38, thiamin 15–23, and riboflavin 6–10 per dry matter and high concentration of the polyphenols (Ndolo and Beta 2009). As such, the wheat germ is potentially a nutritious food supplement, as well as an excellent raw source for food preparation. Two approaches are paramount in the commercial mills. In the most widespread method, the middlings containing the germ particles are passed through a pair of smooth rolls where the germ flattened (its high lipid content allows flaking under compression) and separated by sifting. During the compression, some oil transferred to the flour, causing a loss of oil as well as the contamination of the flour. The second method separates the germ in a broken system by a specially designed germ separator; this system requires a large investment in sophisticated equipment and high operational costs (Brandolini and Hidalgo 2012). On the practice of the flour refining, all the precocious nutrients excluded from the bread and, as mentioned above, routinely delivered to the livestock feeding. Thereafter, people trying methods on how to use the wheat germ ingredients in human foods while the simple solution of baking whole-bread is mostly ignored.

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The Nucellus The maternal tissue immediately surrounding the endosperm and the embryo is the nucellar epidermis. The compressed epidermis with its thin outer cuticle is all that remains of the nucellus, the mass of tissue in which the endosperm and embryo developed. The nucellar epidermis also called the hyaline layer or perisperm and regarded as a seed coat. Between the nucellar layer and aleurone, there is an amorphous layer.

The Testa Has to split open by the radicle before the germination can proceed. The true seed coat is the testa or the spermoderm. Its inner face lies adjacent to the cuticle of the nucellar epidermis where present. The cuticle of the testa is thicker than that of the nucellar where it attaches to the pigment strand while the epidermis and it comprises two layers. The cuticle of the testa thought to be responsible for the relative impermeability of the grain to water over most of its surface.

The Pericarp The pericarp is thus parts of the fruit but not of the seed. They are dry empty cells, some maintaining their shape and the integrity of the layers. Other cells shrank and distorted leaving large frequent intercellular spaces. The innermost fruit coat is the inner epidermis of the pericarp. It is an incomplete layer comprising isolated groups of wormlike cells, the shape of which inspires the description tube cells, by which they usually knew. The long axes of tube cells lie parallel to the long axis of the embryo.

The Endosperm The endosperm is a short-lived tissue adapted for the nutrient storage. In the cereals, the endosperm occupies the major part of the seed and consists of the starchy inner endosperm cells, which are dead at the time of the full maturation, and one or several outer layers of the living aleurone cells, which secrete the enzymes needed to break down the reserves following the germination. The endomembrane system of the developing cereal endosperm is influenced by its functional specialization. The storage protein synthesis requires a highly active and well-developed endoplasmic reticulum and different types of storage organelles rapidly formed during the endosperm development to accommodate various types of storage proteins.

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At the peak of the storage protein production, the programmed cell death occurs in the inner endosperm to generate the starchy endosperm core. To accommodate the sequence of the intracellular changes in the developing and the germinating seeds, the endomembrane system must be extremely flexible and capable of rapid morphological and functional adaptation (Arcalis et al. 2014).

The Aleurone The aleurone is a single cell layer at the inner side of the bran and the outer endosperm side. It contains most of the minerals, vitamins, phenolic anti-oxidants, and lignans of the wheat grain. The epidermal-like aleurone layer forms on the surface of the endosperm and is important for the digesting of the endosperm storage products during the germination. In the cleaved kernels, the cells appear as a square shape or rectangular shape. The kernels characterized by their thick cell walls and the rigid intracellular matrix. Ontologically, the aleurone layer is the outermost cell layer of the endosperm tissue. The sub-aleurone cells also referred to as the peripheral endosperm cells, constitute one row but could be composed of 2 or 3 cell layers. These cells are smaller than the subsequent inner endosperm cells. The starch granules of the peripheral cells are smaller than the cells of the following cell layers. Some fracture profiles reveal that there is more matrix material (mainly proteins and residual cytoplasmic constituents) between the starch granules in these cells compared to inner endosperm cells. The majority of aleurone cells of each species are uniform in size and shape. Most of the aleurone layer removed as part of the bran during roller milling. The removal of the aleurone layer may partially complete when decortication rather than roller milling employed. Aleurone cells are block-­ like, with thick walls and prominent large nuclei, and they occur in continuous layers surrounding the starchy endosperm. In wheat, the aleurone layer is ~50  μm cuboids.

The Sub-Aleurone Cells A layer of 2–3 cells between the starchy endosperm and the aleurone layer that derive from the re-differentiation of aleurone cells with a low starch and high protein, up to 45%, concentrations (Tosi et al. 2011; Shewry 2019).

The Major Ingredients

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The Starchy Endosperm The endosperm cells following the sub-aleurone cells are ‘prismatic’ while the ‘central’ is more variable in shape. The protein matrix usually less pronounced in the central cells compared with the outer prismatic and peripheral cells. There are 2 main size categories. The large granules are generally lenticular whereas the small ones are more spherical or angular. Cleavage of the endosperm cells often occurred along the cell wall. Thus, it was common to see, on a cleavage surface, peripheral components of the individual cells. This could be mainly surfaces of starch granules, alternatively, matrix material lining a cell wall and exhibiting grooves of detached starch granules. The starchy endosperm occurs as a solid mass occupying the center of the grain. The starch granules in the prismatic and the central kernel have the diameters of small spherical granules were up to 10 μm. The larger lenticular granules ranged at 37–40 μm (Evers and Millar 2002; Heneen and Brismar 1987; Becraft and Yi 2011).

The Major Ingredients As the kernel of the main staple food with uncounted varieties and growing conditions, the wheat kernel has very high variability in its content. Therefore, real representative values of the wheat composition are unavailable. However, the data published in many articles through the peered reviewed articles may be used as the best available information for a fair representation of the wheat kernel composition. We have collected data for the wheat kernel composition from >210 sources that published mainly in the ordinary scientific journals. These data do not pretend to represent the global average kernel composition but contains essential information for some of the micronutrients that have not presented yet in this way. We also present the available values of the USDA tables. A value of the USDA table generally averaged from a high number of determinations that considerably higher in their number than for any other source. However, the USDA data mainly or only confined to the US wheat samples. The composition lists (Tables 5.2, 5.4, 5.5, 6.1, 6.2, 8.1, and 8.2) show a partial record of the ingredients found in the wheat kernels and the variability between the data sources. Except for the average, minimal and maximal values we present also the median value. The lower the gap between the average and the median, the higher the reliability of the average value. The energy content not shown because of the high fluctuations between samples mainly attributed to the water content. According to the presented data, consumption of 100  g/d of the whole-wheat may supply some 16% of the total energy intake. The value for the kernel weight/1000 kernels, highly affects the bran yield, the dietary fiber content, and the accompanying ingredients.

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 utrients in the Wheat-Kernel Not Considered by the RDA N as Essential Ingredients Traditionally, sensible nutrition should encompass adequate quantities of the main nutrients (essential amino acids and other protein material, essential fatty acids and other lipids, carbohydrates, dietary fiber, and the major elements), and the specified RDA contents for vitamins and microelements and also adequate amounts of fruits and vegetables. The last decades, incredible information has gathered for the micronutrients present in the foods with the alleviative activity on human health. Even so, no RDA has specified for hundreds of the anti-oxidant compounds embedded in the foods. The intact wheat kernel contains many ingredients that promote remarkably our optimal health with their consumption but these ingredients not referred to the RDA. Choline (vitamin B4) is an excellent example to demonstrate the ingredient that formerly has not counted as an essential one, but effluent intake might improve, remarkably, the health status of the population. Choline, and other methyl donors, present at a quantity of ~2000 μg/g in the whole-wheat kernel (Table 8.6) with a minor amount of the refined wheat flour and a minor amount in all other vegan food items. At a moderate intake of whole-wheat bread, choline may supply a considerable amount or all the amount of the RDA allotment (Yates et al. 1998). However, the common ‘multivitamin’ commercial preparations deprived of the methyl donors probably because of the high quantity needed, because of the comparatively high price of the ingredient, and because of the market of the ‘multivitamins’ has not gained for any authoritative control. The conditional vitamin choline (designated also as vitamin B4) has not included formerly in the RDA list for the vitamins because the human body synthesizes the choline and therefore, overt deficiency symptoms are mostly rare. Only in 1998, the choline classified as an essential nutrient by the Food and Nutrition Board of the Institute of Medicine (USA). Presumably, for a young and healthy person with mild energy expenditure, there is no need to supply choline as a supplement. However, for an old and frail person, choline supplementation may remarkably improve his health status because in his physiological state the endogenic choline synthesis does not meet the optimal requirement. Optimal human health with the lowest relative risks for the non-communicable-­ diseases (NCD) and hence all the other diseases and with the lowest age advancing effects need a stable supply of all of the micro-ingredients. The wheat kernel contains many micro-ingredients with specific qualities and biological activity for each of them. For a comprehensive evaluation of the nutritional quality of the wheat kernel, detailed information is required for every ingredient composes of the wheat kernrel with some sorted main groups (Table 5.1). The total amount of all these ingredients comprise 210 peers reviewed publications (the references for the kernel composition listed in Appendix 1) a,b Minimum or maximum averaged value for the various sources screened. The variation within each source is much higher c USDA Food Tables d Number of resources located at the collected data e The amino acid supply for a 70 kg subject by 100 g wheat, g/d f DRI- Values for adults (g/70 kg/d) (The National Academy Sciences) g Supply of the DRI by 100 g wheat grains, % h Cys + Met i Phe + Tyr

The Wheat Gluten A natural protein found in wheat and many other edible Poaceae species namely rice, corn, barley, sorghum, millet, and oats. Some oat varieties have found as gluten-­free products. Gluten proteins presumably supply the highest protein mass of protein for human nutrition mainly in wheat, rice, and corn than in any other single protein in human nutrition. Gluten comprises a complex of prolamins and glutelins proteins. Gluten has a particular role in the construction of the wheat kernel with an extremely high protein concentration (45%) in the sub-aleurone cells of the starchy endosperm (Shewry 2019). Because of the deleterious activity of the induction of celiac disease in less than 1% of the population, the vast majority of the scientific literature flooded with celiac information and gluten-free products. However, gluten has some other roles in maintaining the basic nutritional needs of humanity. Wheat gluten has an immense impact on human nutrition as it largely determines the processing properties of wheat flour, and in particular the ability to make leavened bread. However, gluten triggers celiac disease and therefore drawn intensive scientific attention for such sensitivity even the celiac disease and the other gluten sensitivities are related to a very small segment of the population. Within the same kernel, a large number of individual gluten proteins are present the presence of multigene families and a high number of post-translational modifications (Shewry 2019). Gluten makes up 80–85% of the total wheat kernel protein which consists the monomeric gliadins (30–60  kDa) and the polymeric glutenin (80  kDa to several million). The gliadins consist of α-, γ- gliadins with 3 or 4 disulfide bonds (S-S), and besides, ω-gliadin that does not consists S-S bond. The glutenin consists of 2 types of low and high polymers linked with S-S bonds. The S-S bonds are the main role in the three-dimensional network of the dough (Ooms et al. 2018). The hydrated gluten has a unique viscoelastic property that enables the production of the modern loaf bread quality. Such a property has gained after the Milena years of the wheat breeding.

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The gluten is a complex structure of prolamins and glutelins proteins and stored with starch in the endosperm of wheat, barley, rye, and oat. Glutens produces the dough viscoelastic properties. The following concentrations in wheat kernel reported in one study (%): water 13.2, protein 11.3, gluten 8.9, prolamins 5.9, and glutenins 3.0 (Schalk et al. 2017). The gluten acts as a membrane-toxin, probably through its antibacterial and antifungal activities, contributing to the defense mechanisms of the plant against predators. The gluten has antibacterial activity against the Gram-­ positive bacteria and Gram-negative bacteria. Contributes to the grain texture and hardness (UNIPROT). The ability of the wheat flour to being process into numerous baked products such as bread, cookies, pasta, tortilla, chapatti or pitta primarily depends on the quality and the quantity of the gluten proteins. Because of the relatively the higher content of the proline and the glutamine amino acids in the gluten structure, gluten also known as prolamine (Barak et al. 2015). The rheological and the functional properties of the wheat gluten depend upon the gliadins/glutenins ratio, molecular size distribution, and the structure of the glutenin polypeptides. The gliadin is one of the major gluten storage proteins of wheat, accounting for 40–50% of the total storage proteins. Significant effects of gliadins on the gluten strength reported. Many researchers have observed a positive relationship between bread loaf volume and gliadins content (Barak et al. 2015). The gluten strength is the most important market quality of the wheat. The gluten composed of two proteins. The glutenin polymerizes forming an elastic nexus, while the gliadin incorporated into a sticky extensible mass entering into the gluten nexus, and induces the dough to become more extensible and flexible. The strong dough, absorb the carbon dioxide produced by the yeast, resulting in even more inflated bread. The gluten has a role in determining the crumb appearance of the cereal product. The flour quality depends on the balance between the gliadin and the glutenin and the appropriate balance between dough viscosity and elasticity and the dough strength. The low gluten elasticity results in a low loaf volume and the high elasticity with a high volume. The glutenin content correlates with the dough strength. The gliadin promotes elongational resistance and dough extensibility. The dough properties are largely dependent on the hydrated gluten protein. The strength and the elastic properties are mainly imparted by the glutenin fraction, whilst gliadin fractions determine the dough extensibility (Varzakas 2016). The non-gluten proteins comprise 15–20% of the total protein of the wheat grain. They are composed of physiologically active or structural monomeric proteins, mainly represented by metabolic, regulatory, and protective enzymes (Victorio et al. 2018). The rheological properties of the dough depending on the balance between the gliadin and the glutenin polymers and especially on the molecular weight distribution of these polymers. The insoluble fractions positively affect gluten viscoelasticity and bread-making quality, being the main contributors to the technological potential of wheat (Victorio et al. 2018). The protein content in the wheat kernel varied with a high range but most of the world production confined to a low range in the protein content.

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79

The glutenin protein thought to responsible for the visco-elastic property of wheat dough. Glutenins coded by several genes on each of the group 1 chromosome of the wheat. Glutenin polymers consist of high molecular weight and low molecular weight glutenin subunits that linked together by S–S bonds and are set free under reducing conditions. Glutenin also contains intramolecular S–S bonds. The intermolecular S–S bonds are of utmost importance in the development of a three-­ dimensional network (Ooms et  al. 2018). Glutenins comprised of aggregated proteins in which individual subunits cross-linked via interchain S–S bonds to give a wide MW of 105  kDa to several million and impart strength and elasticity of the dough.

 luten Has a Biologic Functioning in Plant Biology Rather G Than Coined As a Storage Protein The main kernel protein gluten defined occasionally as a storage protein with presumably functioning as a biological reserve to supply amino acids for the growing seedling. Gluten with its unique structure has some major biological roles in the preservation and widespread of the Poaceae species and in particular the wheat. Gluten comprises several related families of proteins encoded by multigene families with hundreds and more individual proteins in the various wheat species and varieties suggesting a high capacity for the adaptation of the wheat in various environmental conditions. Wheat varieties are known to vary in their resistance to environmental and biological stresses, probably due to individual differences in defense protein levels. The functional properties of the wheat grain are determined mainly by the gluten protein fraction, in terms of both protein content and protein quality, and wheat flours from different millstreams, which derive from different regions of the endosperm, have different breadmaking properties, due to the presence of compositional gradients. Gluten is restricted in distribution to the starchy endosperm cells of the grain, and have not been detected in any other tissues of the grain or plant. Outside the endosperm, the wheat bran proteome is predominantly a sophisticated defense structure that has evolved to fortify the bran layers and to protect the embryo and nutrient-rich endosperm. Clear gradients exist in protein concentration across the starchy endosperm, being high in the sub-aleurone cells and lower in the central starchy endosperm cells. Consequently, the sub-aleurone cells in the dorsal region of the grain contain nearly twice the amount of protein compared with the cells adjacent to the endosperm cavity. The protein gradient is not only quantitative but also qualitative, in that different sub-classes of gluten proteins are differentially expressed in different regions of the endosperm. The qualitative and quantitative protein gradients shown by microscopy were also consistent with analyses of flour fractions obtained by pearling of mature wheat grains. The total protein content increased between the outermost fraction and the second fraction and then steadily

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decreased in the fractions corresponding to inner parts of the endosperm. The protein content of the cells of the starchy endosperm varies by over 4-fold, from 45% in the sub-aleurone cells to 8% in the central region. Furthermore, the gluten protein composition also varies, with the percentage of high molecular weight glutenin subunits increasing and the proportion of low molecular weight subunits and gliadins (Jerkovic et al. 2010; Shewry 2019; Tosi et al. 2011).

The Gliadins Gliadin is one main component of the gluten (Iftikhar and Ali 2017). A ratio of 0.57 (gliadin/glutenin) was reported in one study (Plessis et al. 2013). Gliadins subdivided into α-, γ- and ω-gliadin with 6–8 cysteines (CSH) residues of α- and γ-gliadin are involved in 3 and 4 intramolecular disulfides (SS) bonds (Ooms et al. 2018). The rheological and the functional properties of the wheat gluten depend upon the gliadins/glutenins ratio, molecular size distribution, and the structure of the glutenin polypeptides. The gliadin is one of the major gluten storage proteins of wheat, accounting for 40–50% of the total storage proteins. Significant effects of gliadins on the gluten strength reported. Many researchers have observed a positive relationship between bread loaf volume and gliadins content (Barak et al. 2015).

The Glutenin The protein thought to responsible for the visco-elastic property of wheat dough. Glutenins coded by several genes on each of the group 1 chromosome of the wheat. Glutenin polymers consist of high molecular weight and low molecular weight glutenin subunits that linked together by S–S bonds and are set free under reducing conditions. Glutenin also contains intramolecular S–S bonds. The intermolecular S–S bonds are of utmost importance in the development of a three-dimensional network (Ooms et al. 2018). Glutenins comprised of aggregated proteins in which individual subunits cross-linked via interchain S–S bonds to give a wide MW of 105 kDa to several million and impart strength and elasticity of the dough.

The Friabilin Grain hardness physically hard or soft. Nearly all of the world trade identified as being either soft or hard wheat. The difference in the texture results from the expression of one major gene. A 15-kDa marker protein for the grain softness termed “friabilin,” is present on the surface of the water-washed starch from the soft wheat in high amounts and on the hard wheat starch in small amounts and is absent on the durum wheat

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81

starch. The N-terminal sequence analysis of friabilin indicated a mixture of 2 discrete polypeptides termed “puroindolines”. The association between the friabilin and the surface of the starch-granule mediated apparently by the polar lipids. High amounts are present in soft wheat starch, low amounts are present on hard wheat starch, and there is none on durum (Giroux and Morris 2002).

The Wheat Globulin Since globulins are typically not the major storage protein found in monocotyledonous plant seeds, it would be reasonable to suggest that they would not serve as the major carbon and nitrogen reserve for the seed germination. For this particular task, it is logical that dissociation and disulfide bonds not observed in monocots since their regulatory role in the protein hydrolysis during germination would not be as important as compared to those of dicotyledonous plant seeds (Marcone 1999).

The Vital Gluten The vital gluten is an industrial product that marketed as an ingredient for the bakery industry and usually added to the weak wheat flour of poor bread-making quality to improve its viscoelastic properties, or it incorporated in bread formulations where the gluten from wheat flour diluted (Ooms and Delcour 2019), as flour including the bran (Ortolan and Steel 2017). The vital gluten defined as the ‘cohesive, visco-elastic proteinaceous material prepared as a by-product of the isolation of starch from wheat flour’. The most significant aspect of the gluten story for the food industry is the importance (and the potential) of gluten as a commodity, sold for a wide range of uses around the world. In its most familiar form, gluten traded in the dried state as ‘Vital Wheat Gluten’. Some processes have developed for the production of dried gluten. The vital gluten refers to the product that easily dehydrated and may use as a dough rising additive. In this form, the functional properties of wheat gluten may regenerate by rehydration. Besides, many products derived from gluten by various forms of modification, thereby suiting them to a wide range of value-added uses. The proteins that form gluten are storage proteins, according to their function for the wheat grain. The major global vital gluten production (~63%) directed for the baking industry (Day et al. 2006). An increase in the global vital wheat gluten market in 2018 observed that driven by the change in eating habits of the consumers along with inclination of consumers towards healthy foods and arising awareness of health for an active lifestyle. The non-vital wheat gluten is gluten that has subjected to irreversible denaturation and, therefore, cannot “revived”. The non-vital usually used for protein enrichment, but not for its viscoelastic properties. On the other hand, vital wheat gluten, when in contact with water, can rapidly hydrated and recover its viscoelas-

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tic properties (elasticity and extensibility), due to gliadins and glutenins, which form the gluten network (Ortolan and Steel 2017).

The Amino Acids The wheat is the most widely grown crop in the world used for the human food in the temperate countries and provides ~20% of all of the food energy to the population of the world and a similar proportion of protein for ~2.5 billion people in the less-developed countries. Within the wheat breeder, noteworthy attention was paid to the enhancing of the protein quality, especially the balance between the amino acids in the wheat grains. Thus, amino acid composition became the main issue in wheat production. An efficient approach such as breeding of high-lysine wheat cultivars or determining optimal cultivation management needed to improve the lysine content and the other essential (indispensable) (Zhang et al. 2017). The indispensable amino acid (National Academy Sciences, Engineering Medicine US 2006) does not supply evenly by the wheat kernel (Table 5.2). While tryptophan supplied a rate of 57% of the DRI (by 100 g/d wheat for a 70 kg body weight), lysin supplied only at the rate of 13%. Because the wheat comprises a considerable part of the protein supply in some of the undeveloped countries a high pressure imposed on the wheat breeders to increase the protein quality and in particular the lysine content of the wheat kernel. However, a high gape observed for the lysine and the sulfuric amino acids. In some of the less developed countries in which a single cereal may account for a major part of the total protein intake, the nutritional quality (the content of the indispensable amino acids) of the protein might be critical to cover the amino acids requirements (Shewry 2007). When solely consumed, wheat protein cannot support normal protein accumulation, growth, and optimal physiological condition. Even within the cereals, the wheat protein score for protein accumulation lower than that of the rice, oat, barley, corn, and rye while all cereals scores are much lower than those of the legumes. The amino acid scores of the animal proteins exceed those of all plant proteins (Wolfe et al. 2016; Cervantes-Pahm et al. 2014). Thus, wheat protein remarkably affects the total amino acid balance and the score of the whole-menu if no supplementation of complementary protein available. To tackle the lower amino acids score of the wheat, cereal, the wheat breeders have tried to increase the lysine content of the cereal kernel and the other indispensable amino acids of the cereal proteins. While some advantage has gained in the rice, limited success has achieved in the wheat. Large-scale screening of the USDA World Wheat Collection found only a limited variability (0.37–0.6% of the whole-­ grains) for the lysine content. Lysine in the whole-grain does not always correlate with its content in the grain endosperm. Since lysine is a structural component of proteins, the storage and the processing conditions that affect protein stability will inevitably affect lysine stability. Increase in the lysine content might affect many

The Wheat Kernel Lipids (Table 5.4)

83

Table 5.3  Animal protein intake and the ratio between plant protein and animal proteins by the world regions and the economic levels (Vliet et al. 2015) Region and class Worldwide Region  Africa  Asia  Americas  Europe  Oceania Economic class  1  2  3  4 (highest)

Intake of the animal protein g/capita/d 33

Protein intake ratio Plant/Animal 1.38

15 26 52 58 62

3.35 1.94 0.79 0.75 0.59

13 23 38 59

3.76 1.94 1.17 0.72

processing and cooking conditions and may influence the lysine stability (Yu and Tian 2018). In the countries where affluent animal protein supplemented, the low nutritional score of the wheat does not consider. The consumption of the animal protein and the ratio of plant protein to animal protein consumption are highly varied between the world regions and the economic classes (Table 5.3). In the regions with the high wheat consumption and with a low animal protein intake, the possible increase in the wheat indispensable amino acids and particular lysine and methionine may considerably improve the nutritional status.

The Wheat Kernel Lipids (Table 5.4) The kernel lipids have the lowest content within the main organic nutrients of the wheat kernel. However, wheat lipids in the whole-wheat may supply a considerable part of the essential fatty acids (Ghafoor et al. 2017) but the essential fatty acids with the other unsaturated fatty acids are most vulnerable to oxidation causing a decrease in the shelf-­life. Wheat kernels typically contain 2.5–3.3% lipids, of which 30–36% found in the germ, 25–29% in the aleurone, and 35–45% in the endosperm. Wheat contains the same typical plant lipid classes that other cereals also do. The nonpolar lipids are primarily present in the germ and aleurone, while almost all the polar lipids occur in the endosperm as remnants of amyloplast and other membranes. The lysopolar lipids and lysophosphatidylethanolamine are predominantly present as starch internal lipids. As a result of the milling, the polar lipids in the endosperm end up in the flour, together with a portion of the germ and aleurone nonpolar lipids. The research area of plant lipid genetics and biosynthesis is very complex. The kernel hardness mainly depends on the kernel proteins but also on the

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Table 5.4  Wheat kernel lipids Total lipids, % of WK  Total lipids in refined flour, % Fatty acids distribution, % of total lipids  16:0  18:0  18:1  18:2  18:3  20:0  20:1 Total saturated, % of total lipids Total monounsaturated, % of lipids Total polyunsaturated, % of lipids

Average Median Mina Maxb SD 2.23 2.24 1.1 3.2 0.5 1.12 20.2 1.73 18.2 52 4.2 0.24 0.69 22 18.9 56

18.9 1.12 17.0 56 4.0 0.23 1.38 20 18.4 60

16.0 0.13 15 35 2.7 0.07 0.69 16 15.7 37

29.3 4.8 22 58 6.5 0.41 0.69 35 22.7 6.5

5.3 1.8 3.1 9.8 1.4 0.14 0.58

USDAc nd 2.2 26 2 5 5 5 5 5 4 3

Data collected from >210 peers reviewed publications (the references for the kernel composition listed in Appendix 1) a,b Minimum or maximum averaged value for the various sources. The variation within each source is much higher c USDA Food Tables d Number of resources from the data collected

interaction between the kernel lipids and the proteins (Pauly et al. 2013). The polar lipids in the flour improve baking quality and reduce crumb firming, whereas neutral lipids negatively affect loaf volume and produce a hard crumb (Mense and Faubion 2017). The essential fatty acid, linoleic acid (C 18:2), (Fig. 5.1), and linolenic (C 18:3), (Fig. 5.2) comprises the main lipid fraction in the wheat kernel with an average content and (range of the total lipids) of 2.8 (4–10) 44 and (49–60) mg/g wheat respectively. Both fatty acids comprise of 18 carbon chain (as for the oleic (C 18:1) which is not essential fatty acid). The total amount of these 2 essential fatty acids in the whole-wheat cover the considerable amount of the requirement for these essential fatty acids while the content of the refined flour is much lower. In the US diet, the total linoleic acid content is ~14 g/d (Choque et al. 2014). While the flour lipids constitute a minor component of the flour content and 210 peers-reviewed publications (the references for the kernel composition listed in the Appendix 1) a,b Minimum or maximum averaged value for the various sources. The variation within each source is much higher c The RDA for adult males d As % of RDA supplied by 100 g whole-wheat by the average value for an adult male

(Na) content in the wheat kernel on the daily intake. The vast majority of sodium intake by wheat products derived from the sodium added on the baking procedures. The range in mineral content of the flour produced partially by the differences in varieties but the main effect of the variation produced by the differences in the soil concentration and the growing conditions. While 100 g wheat supply about 15 to 30% of the total energy requirements, some microelements such as molybdenum (Mo) and chromium (Cr) supplied at the levels of some 200–400% of the RDA. The wheat products supply substantial coverage of the microelements (Kamal-Eldin 2007), but with very high variation between various deliveries. With the increase in the world wheat trade, such a variation of the staple food might affect significantly the daily intake. In the country with a high rate of imported wheat, a massive shift of the supply source may change drastically the

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balance of a specific microelement. The whole-wheat flour contains 1400 μg/g magnesium (Mg) while only 160 for the refined flour (Table 4.1). Presumably, the magnesium content in the wheat kernels has a particular high fluctuation. The magnesium content in seeds declined markedly after 1968 in parallel to the Green Revolution and the history of heavy chemical fertilization in agriculture. Consequently, most people absorblower Mg from cereals than the estimated indexes (Guo et al. 2016). The 4 listed toxic elements (Pb, Hg, As, Cd) have a generally negative effect. Because in some areas of wheat cultivation an elevated concentration might despoil the wheat quality, with the advancing of the laboratory equipment monitoring of the toxic elements is required.

References Arcalis E, Ibl V, Peters J, Melnik S, Stoger E (2014) The dynamic behavior of storage organelles in developing cereal seeds and its impact on the production of recombinant proteins. Front Plant Sci 5:439. https://doi.org/10.3389/fpls.2014.00439 Arena S, D’Ambrosioa C, Vitale M, Mazzeo F, Mamone G, Stasio LD, Maccaferri M, Curci PL, Sonnante G, Zambrano N, Scaloni A (2017) Differential representation of albumins and globulins during grain development in durum wheat and its possible functional consequences. J Proteome 162:86–98. https://doi.org/10.1016/j.jprot.2017.05.004 Barak S, Mudgil D, Khatkar BS (2015) Biochemical and functional properties of wheat gliadins: a review. Crit Rev Food Sci Nutr 55:357–368. https://doi.org/10.1080/10408398.2012.654863 Becraft PW, Yi G (2011) Regulation of aleurone development in cereal grains. J Exp Bot 62:1669– 1675. https://doi.org/10.1093/jxb/erq372 Brandolini A, Hidalgo A (2012) Wheat germ: not only a by-product. Int J Food Sci Nutr 63:71–74. https://doi.org/10.3109/09637486.2011.633898 Cervantes-Pahm SK, Liu Y, Stein HH (2014) Digestible indispensable amino acid score and digestible amino acids in eight cereal grains. Br J Nutr 111:1663–1672. https://doi.org/10.1017/ S0007114513004273 Choque B, Catheline D, Rioux V, Legrand P (2014) Linoleic acid: between doubts and certainties. Biochimie 96:14–21. https://doi.org/10.1016/j.biochi.2013.07.012 Day L, Augustin MA, Batey IL, Wrigley CW (2006) Wheat-gluten uses and industry needs. Trends Food Sci Technol 17:82–90. https://doi.org/10.1016/j.tifs.2005.10.003 Evers T, Millar S (2002) Cereal grain structure and development: some implications for quality. J Cereal Sci 36:261–284. https://doi.org/10.1006/jcrs.2002.0435 Finnie SM, Jeannotte R, Faubion JM (2009) Quantitative characterization of polar lipids from wheat whole-meal, flour, and starch. Cereal Chem 86:637–645. https://doi.org/10.1094/ CCHEM-86-6-0637 Ghafoor K, Özcan MM, AL-Juhaımı F, Babıker EE, Sarker ZI, Ahmed IAM, Ahmed MA (2017) Nutritional composition, extraction, and utilization of wheat germ oil: a review. Eur J Lipid Sci Technol 119:1600160. https://doi.org/10.1002/ejlt.201600160 Giroux MJ, Morris CF (2002) Wheat grain hardness results from highly conserved mutations in the friabilin components puroindoline a and b. Proc Natl Acad Sci 95:6262–6266. https://doi. org/10.1073/pnas.95.11.6262 Guo W, Nazim H, Liang Z, Yang D (2016) Magnesium deficiency in plants: an urgent problem. Crop J 4:83–91

References

89

Hemdane S, Jacobs PJ, Dornez E, Verspreet J, Delcour JA, Courtin CM (2016) Wheat (Triticum aestivum L.) bran in bread making: a critical review. Compr Rev Food Sci Food Saf 15:28–42. https://doi.org/10.1111/1541-4337.12176 Heneen WK, Brismar K (1987) Scanning electron microscopy of mature grains of rye, wheat and triticale with emphasis on grain shrivelling. Hereditas 107:147–162. https://doi. org/10.1111/j.1601-5223.1987.tb00280.x HMDB. http://www.hmdb.ca/hml Iftikhar A, Ali I (2017) Kernel softness in wheat is determined by starch granule bound Puroindoline proteins. J Plant Biochem Biotechnol 26:247–262. https://doi.org/10.1007/ s13562-016-0387-1 Jerkovic A, Kriegel AM, Bradner JR, Atwell BJ, Roberts TH, Willows RD (2010) Strategic distribution of protective proteins within bran layers of wheat protects the nutrient-rich endosperm. Plant Physiol 152:1459–1470. www.plantphysiol.org/cgi/doi/10.1104/pp.109.149864 Kamal-Eldin A (2007) Chap 5: Micronutrients in cereal products: their bioactivities and effects on health. In: Hamaker BR (ed) Technology of functional cereal products. Woodhead Publishing Limited, Cambridge, pp 86–111. https://doi.org/10.1533/9781845693886.1.86 Laddomada B, Caretto S, Mita G (2015) Wheat bran phenolic acids: bioavailability and stability in whole-wheat-based foods. Molecules 20:15666–15685. https://doi.org/10.3390/ molecules200915666 Marcone MF (1999) Biochemical and biophysical properties of plant storage proteins: a current understanding with emphasis on 11S seed globulins. Food Res Int 32:79–92. https://doi. org/10.1016/S0963-9969(99)00061-7 Mense AL, Faubion JM (2017) Effects of aging new crop wheat and whole-wheat flour on breadmaking quality and glycolipid composition. Cereal Foods World 62:4–10. https://doi. org/10.1094/CFW-62-1-0004 National Academy Sciences, Engineering Medicine US (2006) Chapter: E DRI Values for indispensable amino acids by life stage and gender group. https://www.nap.edu/read/11537/ chapter/53 Ndolo VU, Beta T (2009) Comparative studies on composition and distribution of phenolic acids in cereal grain botanical fractions. Cereal Chem 91:522–530 Oenel A, Fekete A, Krischke M, Faul SC, Gresser G, Havaux M, Mueller MJ, Berger S (2017) Enzymatic and non-enzymatic mechanisms contribute to lipid oxidation during seed aging. Plant Cell Physiol 58:925–933. https://doi.org/10.1093/pcp/pcx036 Onipe OO, Jideani AIO, Beswa D (2015) Composition and functionality of wheat bran and its application in some cereal food products. Int J Food Sci Technol 50:2509–2518. https://doi. org/10.1111/ijfs.12935 Ooms N, Delcour JA (2019) How to impact gluten protein network formation during wheat flour dough making. Curr Opin Food Sci 25:88–97. https://doi.org/10.1016/j. cofs.2019.04.0012214-7993 Ooms N, Jansens KJA, Pareyt B, Reyniers S, Brijs K, Delcour JA (2018) The impact of disulfide bond dynamics in wheat gluten protein on the development of fermented pastry crumb. Food Chem 242:68–74. https://doi.org/10.1016/j.foodchem.2017.09.007 Ortolan F, Steel CJ (2017) Protein characteristics that affect the quality of vital wheat gluten to be used in baking: a review. Compr Rev Food Sci Food Saf 16:369–381. https://doi. org/10.1111/1541-4337.12259 Palmer R, Cornuault V, Marcus SE, Knox JP, Shewry PR, Tosi P (2014) Comparative in situ analyses of cell wall matrix polysaccharide dynamics in developing rice and wheat grain. Planta 241:669–685. https://doi.org/10.1007/s00425-014-2201-4 Pareyt B, Finnie SM, Putseys JA, Delcour JA (2011) Lipids in bread making: sources, interactions, and impact on bread quality. J Cereal Sci 54:266–279. https://doi.org/10.1016/j.jcs.2011.08.011 Pauly A, Pareyt B, Fierens E, Delcour JA (2013) Wheat (Triticum aestivum L. and T. turgidum L. ssp. durum) kernel hardness: II. Implications for end-product quality and role of puroindolines therein. Compr Rev Food Sci Food Saf 12:427–438. https://doi.org/10.1111/1541-4337.12018

90

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Plessis A, Ravel C, Bordes J, Balfourier F, Mar P (2013) Association study of wheat grain protein composition reveals that gliadin and glutenin composition are trans-regulated by different chromosome regions. J Exp Bot 64:3627–3644. https://doi.org/10.1093/jxb/ert188 Radchuk V, Borisjuk L (2014) Physical, metabolic and developmental functions of the seed coat. Front Plant Sci 5:510. https://doi.org/10.3389/fpls.2014.00510 Rasheed A, Xia X, Yan Y, Appels R, Mahmood T, He Z (2014) Wheat seed storage proteins: advances in molecular genetics, diversity and breeding applications. J Cereal Sci 60:11–24. https://doi.org/10.1016/j.jcs.2014.01.020 Schalk K, Lexhaller B, Koehler P, Scherf KA (2017) Isolation and characterization of gluten protein types from wheat, rye, barley and oats for use as reference materials. PLoS One 12:0172819. https://doi.org/10.1371/journal.pone.0172819 Shewry PR (2007) Improving the protein content and composition of cereal grain. J Cereal Sci 46:239–250. https://doi.org/10.1016/j.jcs.2007.06.006 Shewry P (2019) What is gluten—why is it special? Front Nutr 6:101. https://doi.org/10.3389/ fnut.2019.00101 Tosi P, Gritsch CS, He J, Shewry PR (2011) Distribution of gluten proteins in bread wheat (Triticum aestivum) grain. Ann Bot 108:23–35. www.aob.oxfordjournals.org. https://doi.org/10.1093/ aob/mcr098 UNIPROT. https://www.uniprot.org/ USDA Food Tables (2019) FoodData Central USDA. http://www.ars.us da.gov/nutrientdata Varzakas T (2016) Quality and safety aspects of cereals (wheat) and their products. Crit Rev Food Sci Nutr 56:2495–2510. https://doi.org/10.1080/10408398.2013.866070 Victorio VCM, Souza GHMF, Santos MCB, Vega AR, Cameron LC, Ferreira MSL (2018) Differential expression of albumins and globulins of wheat flours of different technological qualities revealed by nanoUPLC-UDMSE.  Food Chem 239:1027–1036. https://doi. org/10.1016/j.foodchem.2017.07.049 Vliet SV, Burd NA, Loon LJCV (2015) The skeletal muscle anabolic response to plant- versus animal-­ based protein consumption. J Nutr 145:1981–1991. https://doi.org/10.3945/ jn.114.204305 Wikipedia. https://www.wikipedia.org/ Wolfe RR, Rutherfurd SM, Kim IY, Moughan PJ (2016) Protein quality as determined by the digestible indispensable amino acid score: evaluation of factors underlying the calculation. Nutr Rev 74:584–599. https://doi.org/10.1093/nutrit/nuw022 Yates AA, Schlicker SA, Suitor CW (1998) Dietary reference intakes: the new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 98:699–706 Yu S, Tian L (2018) Breeding major cereal grains through the lens of nutrition sensitivity. Mol Plant 11:23–30. https://doi.org/10.1016/j.molp Zhang P, Ma G, Wang C, Lu H, Li S, Xie Y, Ma D, Yunji Y, Guo T (2017) Effect of irrigation and nitrogen application on grain amino acid composition and protein quality in winter wheat. PLoS One 12:e0178494. https://doi.org/10.1371/journal.pone.0178494

Chapter 6

The Wheat Carbohydrates

The carbohydrates comprise the mass majority of the kernel substance with the high variability of the long list of the ingredients repertoire. Their characterization defined according to two main categories: 1 . The digestibility classification determined by the physiological methodologies. 2. The chemical classification determined by the chemical analyses. The digestibility classification shows three main fractions detected according to their degradability along the gut: 1.1 The mass majority of the carbohydrates digested in the upper gut by the enzymes secreted into the intestinal lumen. 1.2 Fermentable residues of the digesta (that was not digested in the small intestine) delivered from the ileum into the colon. In the colon, the enormous population of the microbiota ferments a considerable amount of the digesta by the microbiota enzyme produced mainly by the colonic prokaryotic cells. 1.3 Non-fermentable residues of the digesta finally excreted outside the gut. Each of these three fractions contains many sub-fractions that routinely characterized by the chemical methodology. The carbohydrates are the main constituent of the wheat kernel comprises of starch (the main carbohydrate), non-starch polysaccharides, and free sugars (Table 6.1). The main differences in the kernel composition of the main cereals namely barley, corn, oats, winter rye, winter triticale, and winter wheat are shown in the crude fiber with the highest content in the small grain, oats with 39 mg/kernel, and the lowest content in the largest kernel, corn with 288 mg/kernel (Table 6.2). The corn contains a lower protein content in comparison to the other cereals and a higher lipid content ~2,5 fold higher than that of the wheat. The starch comprises the vast majority of the kernel mass. However, some minor carbohydrates with very low content such as uronic acids, mannose, and other ingredients might have some particular qualities that will attract the wheat breeder to the newer areas. Each of the main fractions (such as starch, non-starch © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_6

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Table 6.1  The wheat kernel carbohydrates Carbohydrates, % of wheat kernel (WK)  Starch, % of WK  Glucose, % of WK  Galactose, % of WK  Arabinose, % of WK  Pentosans, % of WK  Xylose, % of WK  Mannose, % of WK  Fructans, % of WK   β-glucans, % of WK  Amylose, % of starch  Amylopectin, % of starch  Arabinoxylan, % of starch  Free sugars    Glucose, % of WK    Fructose, % of WK    Sucrose, % of WK    Raffinose, % of WK  Total free sugars, % of WK  Dietary fiber, % of WK  Hemicellulose, % of WK  Uronic acid, % of WK  Cellulose, % of WK  Lignin, % of WK  Cellulose, % of WK  Resistant starch, % of WK Soluble (fermentable), % dietary fibere Insoluble (non-fermentable), % dietary fibere

Average Median Mina Maxb SD 69.1 71.1 59.4 75.4 5.9 64.2 71.6 0.47 5.4 5.9 5.2 0.44 1.45 0.73 28.1 44 4.7 0.025 0.03 0.99 0.62 1.4 13.2 6.9 1.11 2.3 1.6 2.1 2.5 21

64.1

4.5 6.4 4.2 1.36 0.72 30.3 5.7

1.46 13.2 6.9 2.2 1.5 2.1 3.0

51.5 63.1 0.33 2.5 4.2 3.4

73.8 80.0 0.60 10.0 6.6 8.0

0.90 0.50 16.5 42 1.9

2.25 1.4 36.0 46 7.1

USDAc Sourcesd 71.5 8

5.3

3.6 1.1 2.5 0.45 0.19 6.6 2.3

0.68 1.3

0.44

0.09 9.4 6.3 0.52 1.4 0.7 1.3 1.2

0.86 2.5 1.5 11.9 0.5

2.5 15.5 7.4 1.7 3.3 2.6 2.6 3.2

0.8 0.6 0.4 1.1

19 2 2 4 4 3 1 6 18 7 2 10 1 1 2 1 5 34 3 2 4 15 9 3

79

Data collected from >210 peers reviewed publications (the references for the kernel composition listed in the Appendix 1) WK whole-kernel a,b Minimum or maximum averaged value for the various sources. The variation within each source is much higher c The USDA food tables d Number of resources collected from published articles e Average calculated from soft and hard Canadian varieties (Ragaee et al. 2012)

p­ olysaccharides, and fiber) classified into, soluble and insoluble fractions. The resistant starch fraction detected by the methodology of the in vitro digestion (not shown here). Each of these fractions is a polymer of simple sugars such as arabinose, xylose, mannose, galactose, and glucose (Figs. 6.1, 6.2, 6.3, 6.4, and 6.5).

6  The Wheat Carbohydrates

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Table 6.2  A comparison between the kernel composition of the carbohydrate and fiber fractions of the main cereals

1 2 3 4 5 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Tested varieties Dry matter Crude ash Crude protein Sum of amino acids Ether extract lipids Nitrogen-free extract Starch Gross energy, kcal/g 1000 seeds, g Test weight, kg/100 L Dietary fiber parameters Crude fiber Neutral detergent fiber Acid detergent fiber Acid detergent lignin Cellulose Klason lignin Free sugars Total sugars  Glucose  Fructose  Sucrose  Fructans Non-starch polysaccharides Total non-starch polysaccharides Non-soluble β-glucans Arabinoxylans Arabinose Xylose Mannose Galactose Glucose Uronic acid Soluble Nonstarch polysaccharides β-glucans Arabinoxylans Arabinose

% per dry matter, means Barley Corn Oats 21 27 14 88.2 90.3 89.3 2.5 1.3 2.8 12.3 9.4 12.7 11.8 9.4 12.2 2.9 5.7 5.2 78.7 81.8 68.9 61.6 74 49.5 4.47 4.59 4.64 59 288 39 71.7 75.4 54.7

Rye 22 88 1.7 11.7 11.1 1.9 82.9 64.3 4.40 42 76.5

Triticale 21 88 1.8 12.4 11.7 1.9 81.8 69.9 4.40 50 75.3

Wheat 29 87.7 1.6 13.7 13.2 2.2 80.4 71.3 4.45 52 81.1

4.22 18.7 5.55 0.77 2.75 2.21

1.79 14.6 2.96 0.86 1.19 1.82

2.1 13.4 2.89 0.75 1.93 1.7

2.13 12 3.14 0.78 1.44 1.08

1.75 0.18 0.11 1.47 0.6

3.36 0.61 0.18 2.58 2.91

3.01 0.56 0.14 2.32 0.57

1.71 0.19 0.09 1.43 0.98

17.2

13.9

10.3

9.82

4.67 7.74 2.83 4.91 0.37 0.42 5.54 0.35

2.01 8.54 3.49 5.05 0.54 0.45 2.85 0.26

0.66 5.53 2.23 3.29 0.43 0.42 1.72 0.28

0.61 6.37 2.48 3.9 0.24 0.36 1.07 0.29

5.06 2.41 0.97 0.54

4.12 0.66 3.09 1.26

2.06 0.09 1.26 0.52

1.91 0.2 1.39 0.55

1.87 8.89 2.74 0.45

10.4 28.9 12.9 2.05

(continued)

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6  The Wheat Carbohydrates

Table 6.2 (continued)

34 35 36 37 38

Xylose Mannose Galactose Glucose Uronic acid

% per dry matter, means Barley Corn Oats 0.43 0.11 0.19 3.73 0.06

Rye 1.84 0.23 0.15 0.58 0.07

Triticale 0.74 0.13 0.19 0.38 0.07

Wheat 0.85 0.06 0.2 0.19 0.06

The wheat data was collected from >210 peer-reviewed publications (the references for the kernel composition listed in the Appendix 1) (FAO; Haard et al. 1999)

Fig. 6.1  The glucose which composes the building block of the starch, glycogen, and the cellulose and other polymers, shown in two graphical presentations. D-Glucose is a monosaccharide containing six carbon atoms with an aldehyde group and therefore referred to as an aldohexose. The glucose molecule can exist in an open-chained (acyclic) and ring (cyclic) form, the latter being the result of an intramolecular reaction between the aldehyde C atom and the C-5 hydroxyl group to form an intramolecular hemiacetal. In water solution, both forms are in equilibrium and at pH 7 the cyclic one is predominant. The glucose is a primary source of energy for the living organisms. It is naturally occurring and found in fruits and other parts of the plants in its free state. In the animals, the glucose arises from the breakdown of glycogen. The glucose synthesized in the liver and the kidneys from non-carbohydrate intermediates, such as pyruvate and glycerol, by a process known as gluconeogenesis. The starch composes entirely from the glucose (Bertoft 2017). Water solubility 1.2 g/mL; density 1.54 g/mL

Each cultivar and genotype has a specific structure that composes the endosperm and exerts a specific activity on the digestion of the upper gut and the residual fraction in the lower gut. Besides the major role of the kernel protein on the baking quality, the carbohydrate composition has also a marked effect on the baking quality whereas some of the effects or probably a major part of the effect produced by the response of the yeast activity to the carbohydrate structure. Within the generations of wheat breeding, the wheat carbohydrates selected for the optimal baking quality while no methodology has employed for the optimization of the carbohydrate structure of the kernel for better physiological activities in the gut.

The Starch

95

Fig. 6.2 The amylose. The amylose defined as a linear molecule of (1→4) linked α-D-­ glucopyranosyl units but is well established that some molecules are slightly branched by the (1→6)-α-linkages. The oldest criteria for the linearity consisted of the susceptibility of the molecule to complete hydrolysis by the β-amylase. This enzyme splits the (1→4) bonds from the non-­ reducing end of a chain releasing the β-maltosyl units but cannot cleave the (1→6) bonds. When degraded by pure β-amylase, linear macromolecules completely converted into maltose, whereas branched chains give also one β-limit dextrin consisting of the remaining inner core polysaccharide structure with its outer chains recessed. The starches of the different botanical origins possess different granular sizes, morphology, polymorphism, and enzyme digestibility. These characteristics related to the chemical structures of the amylopectin and the amylose and their arrangement in the starch granule (HMDB)

While the coefficients of variations of the amino acids composition of the wheat protein stay at a low range of about 3% (not presented), the coefficients of variations for the carbohydrate fractions are much higher at the range of 8–28%. The highest coefficients of variations calculated for total non-starch polysaccharides with a range of 22–62% with an exception of low value for the nonstarch polysaccharides. For an optimal activity of the human gut, these variations in carbohydrate kernel composition should take into account for further breeding of wheat genotypes and a better gut activity.

The Starch The starch is an essential component of an equilibrated diet, is present in all cereals grains, in the roots and tubers such as potato and cassava, and the legumes such as peas. During food processing, the starch mainly undergoes non-chemical transformations (Delcour et al. 2010). The starch composes entirely from glucose (Bertoft 2017) (Fig. 6.1), but with two main structures. The starch is the main kernel ingredient and its composition and structure are very important because of the two main reasons:

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6  The Wheat Carbohydrates

Fig. 6.3  The amylopectin is a highly branched polymer of the glucose found in the plants. It is one of the two components of the starch, the other being amylose. It is insoluble in water. The glucose units linked linearly way with α-(1→4) bonds. The branching takes place with α-(1→6) bonds occurring every 24–30 glucose units. Its counterpart in the animals is glycogen that has the same general composition and structure, but with more extensive branching. The branching occurs every 8–12 glucose units. The starch is made of about 80% amylopectin. The amylopectin is highly branched, formed of 2,000–200,000 glucose units. Its inner chains formed of 20–24 glucose subunits. The glucose residues are linked through α-1,4 glycosidic linkages (HMDB)

(a) Nutritionally, starch does not function as a uniform ingredient because of the various compounds digested at different rates while some content (the resistant starch) fermented in the colon. In the colon, the resistant starch comprises the major source of the microbiota energy needs. (b) Part of the starch granules of the wheat kernel undergoes deformations by the milling procedure. The magnitude of this deformation affects the baking procedure and other most important effects on the ingredients in the wheat kernel. The starch is the primary carbon reserve of the plant. It is insoluble, particulate, and chemically inert, making it ideal for long-term storage. The cereals have adopted for the hyperaccumulation of the grain starch under optimal conditions. The starch in the cereal endosperm synthesized to enhance the plant survival in the next generation, while humans are dependent on this storage starch for food. The starch abundance as a naturally occurring compound of the living terrestrial biomass surpassed only by the cellulose and the lignin masses. Because the starch

The Starch

97

Fig. 6.4  Maltose and maltotriose. (a) D-Maltose or malt sugar, is a primary disaccharide in the human diet formed from two units of glucose joined with an α (1→4) linkage. It is the second member of an important biochemical series of glucose chains. The addition of another glucose unit yields maltotriose, further additions will produce dextrins, also called maltodextrins, and eventually starch. Maltose can be broken down into two glucose molecules by hydrolysis in living organisms. At the surface of the small intestine, the brush border enzymes maltase breaks down maltose (HMDB). (b) Maltotriose: A common oligosaccharide metabolite found in human urine after maltose ingestion or infusion (HMDB)

is the principal constituent of the harvestable organ of many agronomic plants, its synthesis, and accumulation also influence the crop yields. The starch synthesized in the plastids of both the photosynthetic and the non-photosynthetic cells. The starch is an insoluble poly-glucan produced by starch synthase using ADP-glucose as the sugar donor molecule. The mature chloroplasts occurring in the photosynthetically active cells possess the capacity of providing the energy and fixed carbon for the synthesis of the starch during the illumination. By contrast, the production of the long-term storage of the starch, taking place in the amyloplasts of the reserve organs such as tubers, roots, and seed endosperms depend upon the incoming s­ upply of the carbon precursors and the energy from the cytosol. This difference between

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6  The Wheat Carbohydrates

Fig. 6.5  Galactose, mannose, and fructose (gray, red and white balls are carbon, oxygen, and hydrogen, respectively) (Wikipedia), shown in two graphical presentations. (a) β-D-galactose is an aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. The D-galactose is an energy-providing nutrient and a necessary basic substrate for the biosynthesis of many macromolecules in the body. The metabolic pathways for the D-galactose are important not only for the provision of these pathways but also for the prevention of the D-galactose and the D-galactose metabolite accumulation. (b) D-Mannose: A high-mannose-type oligosaccharides have shown to play important roles in the protein quality control. (c) D-fructose, or levulose, is an isomer of glucose. Fructose is the sweetest naturally occurring sugar, estimated to be twice as sweet as sucrose with a “fruity” aroma. Although the fructose is a hexose, it generally exists as a 5-member hemiketal ring (a furanose that is responsible for the long metabolic pathway and high reactivity) compared to glucose. It used as a preservative and an intravenous infusion in parenteral feeding

The Starch

99

the metabolic capacities of the chloroplasts and the amyloplasts has led to the generally accepted view that the pathways involved in the starch production are different in the photosynthetic and the non-photosynthetic cells. In the leaves, a portion of the photosynthetically fixed carbon retained within the chloroplasts during the day to synthesize starch, which then remobilized during the subsequent night to support non-photosynthetic metabolism and growth by the continued export of the carbon to the rest of the plant. Due to the diurnal rise and fall cycle of its levels, the foliar starch is termed “transitory starch”. The starch granules consist of tightly packed glucan chains resulting in a semi-crystalline, water-insoluble structure, which is ideally suited for the long-term storage. The various starch-branching enzymes isoforms in the plants shape the structural and functional properties of the starches. In the food industry, the starch-branching enzymes are widely used while they precisely controlled. Starch-branching enzymes that catalyze the trans-­glycosylation of an α-1,4-glucosidic linkage in the α-1,4-α-D-glucan to form a nonreducing-end malto-oligosaccharide chain that then transferred to a C-6 hydroxyl group in a nonreversible reaction resulting in the formation of the α-1,6-branch points within the α-1,4-poly-glucans. These chains organized into two polymers called the amylose (Fig. 6.2) and the amylopectin that occur in a 30:70 ratio in the normal cereal endosperm (Fig.  6.3). The amylopectin is larger than the amylose (molecular weight 106–108 vs. 105–106 g/mole respectively) and has a higher frequency of the branching (every 20 versus 100–10,000 residues respectively). The amylopectin chain is one of the highest known among the naturally occurring polymers. Amylopectin chains subdivided among A-, B-, and C-type chains. The A chains are outer and do not carry other chains. They linked with the inner B chains, which can subdivide into sub-types chains. The amylopectin contains a single C chain that carries the only reducing end. The regularity of the branching in the amylopectin creates glucan chains of the defined lengths that arrayed into the alternating crystalline and the amorphous regions. The size, the shape, and the number of starch granules vary among the different cereal endosperms. The wheat granules are smaller than 5 μm. The functional behavior of the starch intricately linked to its structure and morphology. Changes in the glucan chain length distribution or the degree of the crystallinity can alter the starch physicochemical characteristics. Small changes in the proportion of amylose/amylopectin, in particular, have extensively documented and altered the starch functionality. Such changes also have heavily influenced the nutritional characteristics of starchy foods. During food processing, the starch mainly undergoes non-chemical transformations. In nature, starch occurs as granules (Delcour et al. 2010; Bahaji et al. 2014; Tetlow and Emes 2014; Thitisaksakul et al. 2012). Nutritionally, starch contains two main fractions: (a) the main fraction of the starch that decomposed at the upper intestine. (b) the resistant starch that mostly decomposed in the colon and therefore this fraction is a component of the fermentable dietary fiber.

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6  The Wheat Carbohydrates

The Glycemic Index The appearance of the glucose in the bloodstream following eating depends on the rate of the glucose entry into the circulation, the amount of the glucose absorbed, the rate of disappearance from the circulation, and the hepatic regulation of the glucose release. The dietary carbohydrates have a wide range of effects on the blood glucose with some resulting in a rapid rise followed by rapid fall in blood glucose, while others show an extended rise and slow extended fall in blood glucose (Vega-­ López et al. 2018). Most of the wheat products are known to have a high glycemic index. With the increase in the prevalence of diabetes worldwide, the intentional breeding decrease of the glycemic index of the foods, and in particular an intentional decrease in the staple food can be benefitted for the population (Bharath and Prabhasankar 2014). The glycemic index of a food item equal to the serum glucose response 2 h after the intake of 50  g of the tested item divided by the serum glucose response 2 h after the intake of 50 g of a reference carbohydrates item. The ratio multiplied ×100. The glucose or the white bread used as references with two corresponding values. Each percent equated to a “unit” of the glycemic index. Each nutrient has its specific glycemic index. Whole-wheat products have a range of 56–69 of the glycemic index while white bread defined with a glycemic index of 100 (Mullie et al. 2016). Each food item attains one glycemic index value with glucose and a 2nd with the white bread reference. The white bread has a glycemic index of 70 for glucose as a reference. The wheat kernel starch might be an interesting breeding target for a marked decrease in the glycemic index. With the very high variability in the metabolic pathways of the starch synthesis as shown above, a wide room is opened for an intensive breeding activity to develop a wheat brand with a lower glycemic index. Presumably, different brands are needed for whole-wheat products or refined wheat products. The health benefits of the polysaccharides of the cereal grain contribute to the well-established health benefits associated with the regular consumption of whole-­ grain cereal foods. There is considerable interest in modifying the amounts and the compositions of the starch and the major non-starch polysaccharides (arabinoxylan and β-glucan) to develop new types of cereals with the improved health benefits, notably reduced the glycemic index in the small intestine and improved properties as dietary fiber in the colon. Low glycemic index and high fiber diets have shown to have beneficial effects, including lower post-prandial glucose and insulin responses, improved lipid control, and possibly improved the insulin sensitivity. Although it is not possible to define the precise values for the high or the low glycemic index diets, it is clear that the lower the glycemic index, the greater the metabolic effects. The digestibility of starch is of great importance to human health

The Glycemic Index

101

with a variable proportion remaining undigested in the small intestine and reaching the large intestine as part of the dietary fiber fraction where it fermented by the gut microflora (Lafiandra et al. 2014). Native starches generally contain 20–30% amylose and occur mostly in the form of semi-crystalline granules, which have a very complex hierarchical structure. Starch granules are generally composed of an amorphous bulk core area surrounded by concentric semi-crystalline growth rings alternating with amorphous growth rings. The amorphous core composed mainly of amylose and amylopectin chains disordered at the reducing end. The size of the amorphous core related to the amylose content of the starch. When starch granules hydrated in hot water, it swells and transformed into a paste. This irreversible change referred to as starch gelatinization (Wang et al. 2015). In a survey of >210 wheat lines, a range of 320–840 mg/g starch/dry matter observed (Pritchard et al. 2011). In a limited survey of four studies (Louie et al. 2012; Gellar and Nansel 2009; Nansel et al. 2008; Galgani et al. 2006), increase in 30 units in the dietary glycemic index, resulting in an increase of 20 mg/dL in the glucose peak. Presently, the glycemic index of the whole-wheat bread has ~38 units less than the white bread. With the 30% of the whole-energy intake of the wheat, the intake of the whole-wheat might substantially decrease the prevalence of the elevated blood glucose in the population >45 with a high prevalence of elevated blood glucose (>100) exist. The glycemic index is the main pillar component in the introduction of the whole-wheat bread for refined-wheat bread. As the bread and the other wheat products comprise the largest part of energetic items, they have a major effect on the cumulative effect of the glycemic index. The decrease in the wheat glycemic index is more effective than for any other food group in the menu. However, the intake of the whole-for refined wheat is only the tip of the iceberg of the wheat effect.

The Hexose Hexose is a monosaccharide with six carbon atoms, with the general formula C6H12O6. Hexoses are classified by functional group, with aldohexoses having an aldehyde at position 1 such as glucose. Galactose and manose, and ketohexoses having a ketone at position 2 such as fructose.

Glucose The glucose is a simple sugar with the molecular formula C6H12O6 and composes the starch as a sole component.

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6  The Wheat Carbohydrates

Some Other Hexoses that Found in the Wheat Kernel Hexoses are monosaccharides with six carbon atoms, such as glucose, galactose, mannose, rhamnose, and fructose.

The Nonstarch Polysaccharides Fructans These compounds do not comprise starch. Fructan is a polymer of fructose molecules. Fructo-oligosaccharide is a fructan with a short chain length. Fructans occur in, yacon, jicama, and wheat. Fructans also appear in grass, with dietary implications for horses and other grazing animals. Wheat kernels contain fructans, which is fructose-based oligosaccharide with prebiotic properties. The content is 1.3–35% of dry matter with a decreasing trend towards kernel maturity. Fructans might fulfill a significant role as localized scavengers ROS (reactive oxygen species), both in plants and in human health (Cimini et al. 2015; Shewry and Hey 2015). Mannose Mannose is important in human metabolism, especially in the glycosylation of certain proteins. The mannose comprises only a small fraction of the wheat kernel (Table 6.1). As a natural bioactive monosaccharide, D-mannose is a popular nutritional and health-beneficial food supplement, especially used as a dietary supplement influencing glycol-nutrient contribution to human health. Novel carbohydrates such as D-mannose used as a dietary supplement influencing glycol-nutrient contribution to human health (Hu et al. 2016).

References Bahaji A, Li J, Sánchez-López ÁM, Baroja-Fernández E, Muñoz FJ, Ovecka M, Almagro G, Montero M, Ezquer I, Etxeberria E, Pozueta-Romero J (2014) Starch biosynthesis, its regulation and biotechnological approaches to improve crop yields. Biotechnol Adv 32:87–106. https://doi.org/10.1016/j.biotechadv.2013.06.006 Bertoft E (2017) Understanding starch structure: recent progress. Agronomy 7:56. https://doi. org/10.3390/agronomy7030056 Bharath KS, Prabhasankar P (2014) Low glycemic index ingredients and modified starches in wheat based food processing: a review. Trends Food Sci Technol 35:32–41. https://doi. org/10.1016/j.tifs.2013.10.007 Cimini S, Locato V, Vergauwen R, Paradiso A, Cecchini C, Vandenpoel L, Verspreet J, Courtin CM, D’Egidio MG, Ende WVD, Gara LD (2015) Fructan biosynthesis and degradation as

References

103

part of plant metabolism controlling sugar fluxes during durum wheat kernel maturation. Front Plant Sci 6:89. https://doi.org/10.3389/fpls.2015.00089 Delcour JA, Bruneel C, Derde LJ, Gomand SV, Pareyt B, Putseys JA, Wilderjans E, Lamberts L (2010) Fate of starch in food processing: from raw materials to final food products. Annu Rev Food Sci Technol 1:87–111. https://doi.org/10.1146/annurev.food.102308.124211 FAO, Haard NF, Odunfa SA, Lee CH, Quintero-Ramírez R, Lorence-Quiñones A, Wacher-Radarte C (Eds) (1999) Agricultural services bulletin no 138. http://www.fao.org/docrep/x2184e/ x2184e04.htm Galgani J, Aguirre C, Díaz E (2006) Acute effect of meal glycemic index and glycemic load on blood glucose and insulin responses in humans. Nutr J 5:22. https://doi.org/10.1186/1475-2891-5-22 Gellar L, Nansel TR (2009) High and low glycemic index mixed meals and blood glucose in youth with type 2 diabetes or impaired glucose tolerance. J Pediatr 154:455–458. https://doi. org/10.1016/j.jpeds.2008.09.040 HMDB. http://www.hmdb.ca/hml Hu X, Shi Y, Zhang P, Miao M, Zhang T, Jiang B (2016) d-Mannose: properties, production, and applications: an overview. Compr Rev Food Sci Food Saf 15:773–785. https://doi. org/10.1111/1541-4337.12211 Lafiandra D, Riccardi G, Shewry PR (2014) Improving cereal grain carbohydrates for diet and health. J Cereal Sci 59:312–326. https://doi.org/10.1016/j.jcs.2014.01.001 Louie JCY, Markovic TP, Ross GP, Foote D, Brand-Miller JC (2012) Timing of peak blood glucose after breakfast meals of different glycemic index in women with gestational diabetes. Nutrients 5:22. https://doi.org/10.3390/nu5010001 Mullie P, Koechlin A, Boniol M, Autier P, Boyle P (2016) Relation between breast cancer and high glycemic index or glycemic load: a meta-analysis of prospective cohort studies. Crit Rev Food Sci Nutr 56:152–159. https://doi.org/10.1080/10408398.2012.718723 Nansel TR, Gellar L, McGill A (2008) Effect of varying glycemic index meals on blood glucose control assessed with continuous glucose monitoring in youth with type I diabetes on basal-­ bolus insulin regimens. Diabetes Care 31:695–697. https://doi.org/10.2337/dc07-1879 Pritchard JR, Lawrence GJ, Larroque O, Li Z, Laidlaw HKC, Morell MK, Rahman S (2011) A survey of β-glucan and arabinoxylan content in wheat. J Sci Food Agric 91:1298–1303. https:// doi.org/10.1002/jsfa.4316 Ragaee S, Guzar I, Abdel-Aal E-SM, Seetharaman K (2012) Bioactive components and antioxidant capacity of Ontario hard and soft wheat varieties. Can J Plant Sci 92:19–30. https://doi. org/10.4141/CJPS2011-100 Shewry PR, Hey SJ (2015) The contribution of wheat to human diet and health. Food Energy Secur 4:178–202. https://doi.org/10.1002/FES3.64 Tetlow IJ, Emes MJ (2014) A review of starch-branching enzymes and their role in amylopectin biosynthesis. IUBMB Life 66:546–558. https://doi.org/10.1002/iub.1297 Thitisaksakul M, Jiménez RC, Arias MC, Beckles DM (2012) Effects of environmental factors on cereal starch biosynthesis and composition. J Cereal Sci 56:67–80. https://doi.org/10.1016/j. jcs.2012.04.002 Vega-López S, Venn BJ, Slavin JL (2018) Relevance of the glycemic index and glycemic load for bodyweight, diabetes, and cardiovascular disease. Nutrients 10:1361. https://doi.org/10.3390/ nu10101361 Wang S, Li C, Copeland L, Niu Q, Wang S (2015) Starch retrogradation: a comprehensive review. Compr Rev Food Sci Food Saf 14:568–585. https://doi.org/10.1111/1541-4337.12143 Wikipedia. https://www.wikipedia.org/

Chapter 7

The Dietary Fiber

The Dietary Fiber Definition The vast majority of the polyphenols of the wheat kernel bound or conjugated to the dietary fiber (Table 8.2) (the bounding or the conjugating terms defined by the chemical intensity used in the laboratory to release the polyphenol). Thus, when the whole-wheat consumed, most of its polyphenols released in the colon and together with the dietary fiber exerts particular alleviative effects in the human colon. These effects contribute to the alleviative phenomenon of the whole-wheat intake. While most of the wheat consumed as the refined products, as presently practiced, the physiological effect of the residual dietary fiber is marginal. However, when the wheat products consumed as the whole-wheat for the refined products, such an intake doubles the total amount of the dietary fiber as well as the polyphenols in our menu (Table 10.1). We have no idea which one of these two components, the dietary fiber or the anti-oxidants, has the major role in the healing effects of the whole-wheat. These healing effects, that precisely presented in Table 15.1 produced by all of the ingredients of the whole-wheat kernel with no evidence to distinguish between the activity of the dietary fiber and the activity of the anti-oxidants. Presently, no methodology is available to find out the peculiarity of each ingredient. With the present practice of consumption, by the majority of the subjects of the refined wheat products, there is the inadequate intake of the dietary fiber and insufficient intake of the anti-oxidant compounds. Hence, the definition of the dietary fiber must tightly be interconnected with wheat kernel dietary fiber and the wheat kernel polyphenols because, with a sensible nutrition pattern, the consumption of the whole-wheat consists the major share of the dietary fiber. Such an approach has not adopted by the consensual and the international definition for the dietary fiber that approved by the Codex (Lupton et al. 2009). The particular role of the polyphenols that bound to the wheat dietary fiber has presumably thoroughly ignored by most of the studies and reviews discussing the © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_7

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dietary fiber definition as shown in these two publications (Lupton et  al. 2009; Poutanen et al. 2018). Even the binding of the polyphenols to dietary fiber has discussed but not the major role of the mass release of the polyphenols in the colon (Lupton 2012). The following Codex definitions show that the main attention was paid for the chemical pattern of the dietary fiber as follows (Lupton et al. 2002): Dietary fiber means carbohydrate polymers1 with ≥10 monomeric units, which not hydrolyzed by the endogenous enzymes in the small intestine of humans and belong to the following categories: (a) Edible carbohydrate polymers naturally occurring in the food as consumed. (b) Carbohydrate polymers which have obtained from food raw material by physical, enzymatic or by chemical means and which have shown to have a physiological effect of benefit to health as demonstrated by generally accepted scientific evidence to competent authorities. (c) Synthetic carbohydrate polymers that have shown to have a physiological effect of benefit to health as demonstrated by generally accepted scientific evidence to competent authorities. (d) These substances are included in the definition of fiber insofar as they are associated with the poly- or oligosaccharides fraction of fiber. However, when extracted or even reintroduced into a food containing non-digestible polysaccharides, they cannot define as dietary fiber. When combined with polysaccharides, these associated substances may provide additional beneficial effects (Lupton et al. 2009). The mix-up of the native dietary-fiber, the isolated, and the synthetic in the same Codex definition does not allow the using of the above definition for the sensible practical approach. The isolated dietary fiber widely used in the baking industry to produce light bread with unsupported of reliable nutritional claims. The failure to reach a reliable definition for the dietary fiber has created after a consensual definition for almost each one of the dietary ingredients has well established within the nutrition scientists but not such a consensus has reached for the dietary fiber (American Association of Cereal Chemists - AACC 2001; Richie and Muscat 2015; Johnson 2012; Redgwell and Fischer 2005; Lupton 2012). The experimental studies of the dietary effects of the isolated dietary fiber are questionable because the isolated dietary fiber cannot imitate native dietary fiber (Poutanen et  al. 2017, 2018). While the protein, fat, and carbohydrates defined chemically and assessed by the chemical methodologies that have well established the dietary fiber distinct from all other food ingredients because the main 1  When derived from a plant origin, the dietary fiber may include fractions of lignin and/or other compounds when associated with polysaccharides in the plant cell walls and if these compounds are quantified by the AOAC gravimetric analytical method for dietary fiber analysis: fractions of lignin and the other compounds (protein fractions, phenolic compounds, waxes, saponins, phytates, cutin, phytosterols, etc.) intimately ‘associated’ with plant polysaccharides are often extracted with the polysaccharides in the AOAC method.

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feature of the digestibility or the fermentability cannot define by the chemical analysis and in particular, not with the combined effects with the polyphenols. Because of the peculiar nature of the human colon, the data obtained by animal experimentation scarcely fitted for the human physiology. Presently, the dietary fiber assessment performed by the approximation and the evaluation of some approaches. The chemical analysis supplies only a crude approximation for the definition of dietary fiber. The absence of a comprehensive composition table for all types of dietary fiber for most of the edible foods shows us that no consensus has established for the evaluation of the dietary fiber. The dietary fiber has some further disadvantages for the nutritious assessment because of it’s chemical composition being rapidly changing on the ripening stages. The definition of the dietary fiber should tightly be interconnected with wheat kernel dietary fiber and wheat kernel polyphenols because the consumption of the whole-wheat for the refined products doubles the intake of the dietary fiber and the polyphenols.

The Fermentability On the early days of the enzymology, the catalytic proteins termed “ferments”. The term enzyme coined by the physiologist Wilhelm Kühne in 1878. Today fermentation confined to the microbial activity and no longer used for other enzymatic activities while this distinction has excepted by all of the reputable journals. After the undigested digesta transmitted into the colon, they attacked by trillions of the microbiota cells. Because all the digestible ingredients absorbed by the jejuna and the ilea papilla, the nutrients decomposed in the upper intestine not delivered into the colon. For their survival, the microbiota must attack the glycoside bonds of the undigested residues transferred into the colon. The microbiota populated in our colon have adapted metabolically to the colon environment of the Modern Homo sapiens and many of them may survive efficiently only in the colon environment. In addition to the dietary fiber, the microbiota cells utilize the endogenous residues transferred into the colon from the upper intestine but these residues contain low energy content. The microbiota cells excrete enzymes with a capability to disintegrate the chemical bonds composing the dietary fiber. The unique nature of the wheat polyphenols is a key landmark in the exclusive advantage of the whole-wheat quality in human nutrition. Most of the wheat phytochemicals, including the polyphenols, distinct remarkably from those of (continued)

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(continued) the other edible plants by their chemical affinity. Most of the wheat kernel polyphenols are attached to the kernel ingredients with the bound bonds (mostly to the polysaccharides), those of fruits and vegetables stay free and unbound in the cellular content (Sun et al. 2002). While the phytochemicals of the fruits and vegetables attract the major attention as antioxidants with their ability to decrease the incidence of non-communicable diseases, the wheat polyphenols are not regularly included in the same category (Liu and Adom 2007). The fruits and the vegetables are often cited as an excellent source of antioxidants while the grain phytochemicals are ignored. Two main reasons counted for such a major discrepancy: (a) For generations, the vast majority of the wheat and the other Poaceae intake has undergone routine refining that has systematically withdrawn the vast majority of the phytochemicals outside the consumer range. (b) The methodology required to detect the bound phytochemicals should be more sophisticated than that for the free forms. Part of the ingredients ingested by the microbiota cells and digested inside the microbes. Other digestion activity, occurred outside the microbiota bodies by the enzyme exerted by the microbiota. The fermentation activity operated by the microbiota and processed by the enzymes which all of them are proteins and synthesized by the microbiota. Part of these enzymes operates inside the microbe and the other part in the lumen media of the colon. For an efficient activity of the exerted enzyme to gain an adequate concentration, the microbe should be fixed to a “large” solid residue such as unfermentable dietary fiber. Along with their evolution trait, the mammals and the other higher animals had lost the capacity to produce and excrete the enzymes that break down the polymer bonds of the dietary fiber ingredients. Even in the herbivorous, such as the ruminants or the Equidae (such as horse, and donkey), all the digestion of the dietary fiber performed by the microbiota and not by the enzymes excreted by their eukaryotic cells. Not all the digesta in our colon decomposed by the microbiota and thus two main types of the dietary fiber classified: A. Fermentable dietary fiber is an ingredient that passes almost untouched through the small intestine, reaches the colon, and decomposed by the microbiota. The common term, soluble fiber, refers to a food ingredient that is determined analytically and used as an analytical approximation for the fermentable fiber. B. Non-fermentable dietary fiber is the dietary fiber that excreted in the feces. The term insoluble dietary fiber is an approximation for the chemical analysis of this term.

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Table 7.1  The fermentability rate of the dietary fiber ingredients in the human colon (Brownlee et al. 2006)

Ingredient Lignin Cellulose Hemicellulose Resistant starch Pectin, gum, and mucilage Algae gums Corn bran Wheat bran Oat bran Isolated cellulose

Fermentability, % ~0 10–50 50–80 20–100 50–100 40–60 11 42a 57 0

Asp et al. (1993)

a

This classification of fermentable and non-fermentable is valid for all sources of dietary fiber in our diet such as: (a) whole-wheat products; (b) other cereal products; (c) fruits; (d) vegetables; (e) potato. Potato listed separately because of the nutritional effect of the potato distinct from that of the vegetable. Along with the upper gut, the coefficient of digestibility of the food macronutrients, except that of the dietary fiber, exceeds 90%. The rate of the fermentability (in the colon) of the dietary fiber fluctuates from zero to a full fermentability (Table 7.1). The wide range of fermentability rates produced by the high variability between plant types, maturity and ripening stage, varieties, cultivation conditions, daily menu content, chemical composition, and the individual colon conditions (Davies et al. 2005; Aust et al. 2001; Spiller 2001).

The Dietary Fiber in Human Nutrition In human nutrition, the definition of the macro-nutrients characterized by the daily consumption at a range from a couple of grams to some hundreds g/d. The micronutrients defined as ingredients with the consumption of 100 mg/d fall also into the class of the macronutrients (such as calcium, phosphorus, potassium, or sodium). The daily recommendation for the dietary fiber is 14 g/Mcal with a total consumption for an adult of 25–36 g/d (Johnson 2012; Lupton 2012). The WHO recommendation specifies >25 g/d for an adult (World Health Organization 2003). Within the Western societies, probably no other dietary ingredient regularly consumed at the lower level of the recommendation for the adequate intake as for the

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dietary fiber. In comparison to the recommendation of the >25 g/d published by the WHO, in no country of the Westernized societies the quota of the 25 g has achieved. In most of the countries, a very wide gap continuously kept. The following values for most of the countries have presented, g/d: UK 14; Japan, Canada 15; US, Spain, Belgium, 18; Italy 19; Sweden, Netherlands 20; France, Denmark 21; Poland, Hungary 23; Germany, and Norway 24. The consumption status in adult people and children as in the adult population (Stephen et al. 2017). The relative high consumption in some of the European countries presumably produced by the rye consumption that commonly consumed as the whole-grain. The dietary fiber has hardly reckoned as a macronutrient and thus a major gap still exists in its evaluation of sensible nutrition. Even so, in recent years, dietary fiber has become one of the main targets in sensible nutrition. A human may survive with very low dietary fiber intake or even nourished on a free-fiber diet, but for the best performance, extended longevity encouraged immune system and the highest competence capability his diet must contain adequate and high-quality dietary fiber. Adequate intake of fruits and vegetable are critical for sensible nutrition but a major source of the dietary fiber derived from the whole-grain cereals. The wheat dietary fiber is a unique item in our menu because it might easily accomplish our requirement for the dietary fiber and increase substantially the antioxidant flux. The wheat dietary fiber bound to >half of the antioxidants of the menu and when it properly consumed the vast part of the antioxidants released in the colon. The dietary fiber does not decompose in the upper gut (the stomach, duodenum, jejunum, and the ileum) and mainly delivered untouched into the colon. The dietary fiber comprises two main fractions: ( a) the fermentable fraction that decomposed in the colon. (b) the non-fermentable fraction that delivered into the colon and excreted in feces. Each main fraction composed of all the building blocks of the dietary fiber. The fermentable dietary fiber supports the main energy needs of the colon microbiota while the non-fermentable supports the physical substance for the microbiota activity. The microbiota fermentable activities must be supported by a rigid substance to attain nearby enzyme concentration in a liquid environment that enables the enzyme activity. The dietary fiber has a major drawback in the research preferences because unlike medications, the collected evidence in the research studies is not patented. Such a drawback prevents a massive advantage in the investigation of the effect of the dietary fiber on the human physiology. Many nutritionists consider that no fiber deficiency disorder shown for the low dietary fiber intake (Champ et al. 2003). The consumption of the whole-wheat bread for bread baked from the refined flour increase the dietary intake by two-fold thus enhances considerably the micro-

The Types of Dietary Fiber

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biota activity. While in human colon microbiota is probably the main inducer for the large immune system attached to the gut, enhancement by a mass supply of the dietary fiber might be a key factor in the decrease of the morbidity incidences.

The Types of Dietary Fiber The dietary fiber classified by some different criteria as follows: . the type of plant material such as wheat or rye; A B. solubility: soluble (fermentable) and insoluble (unfermentable); C. the extent of the binding to the other compounds such as polyphenols. D. the main structure of the polymeric construction such as: (a) lignin (Fig. 7.1) (b) cellulose (Fig. 7.2). (c) lignocellulose (d) resistant starch. (e) hemicellulose (Fig. 7.3). (f) pectin (not present in the wheat kernel). (g) gum (not present in the wheat kernel). (h) inulin (not present in the wheat kernel). E. the basic building blocks of each polymeric construction listed above (lignin, cellulose, etc.). The building blocks such as glucose, fructose, xylose, arabinose, galactose, mannose, rhamnose, fucose, glucuronic acid, galacturonic acid, coniferyl alcohol, coumaryl alcohol, and sinaptyl alcohol (Fig. 7.1). The solubility classification is the most important item and the most practical one. However, no one characterization could evaluate the physiological effect of the dietary fiber on the colon fermentation. Each type of fermentable or soluble and non-fermentable or insoluble fractions may further classify according to the main structure (item D, above) and according to the basic building blocks (item E, above). The dietary fiber is mainly concentrated at the outer kernel layers and each main fraction composed of one or more building blocks which most of them have a carbohydrate structure but some composed of lignin structure that does not define as carbohydrate. Wheat dietary fiber varies at a range of 8–15% as collected for the average values of 33 publications (Table 6.1). The lower the specific gravity (kg/hectoliter or pounds/bushel), the lower the 1000 kernel weight, then the higher the bran yield and the dietary fiber content. The data gathered in for the dietary fiber content (Table 6.1) collected from analyses conducted by various methods of analysis. Even so, there is no high variability between the various sources. The consumption of 100 g whole-wheat a day supplies about 16% of the whole-energy intake and supplies ~40% of the suggested daily intake of the fiber. Such an amount is most significant for covering the nutritional needs of the fiber intake. With the consumption of the refined wheat, such benefit disappears.

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a

b

c

d

Fig. 7.1  The lignin precursors, the lignin building blocks (shikimic acid, coniferyl alcohol, 4-­coumaryl alcohol, sinapyl alcohol) (gray, red and white balls are carbon, oxygen, and hydrogen, respectively), shown for the schikemic acid in two graphical presentations. (a) Shikimic acid is a precursor for the lignin biosynthesis. Shikimic acid, (the anionic form shikimate), is a biochemical intermediate in the plants and the microorganisms. It is a precursor for phenylalanine, tyrosine, tryptophan, indole derivatives, alkaloids, and other aromatic metabolites. The shikimic acid used commercially as a base material for the production of the Tamiflu drug. (b) Coniferyl alcohol is a precursor for the lignin biosynthesis. (c) 4-Coumaryl alcohol is a precursor for the lignin biosynthesis. (d) Sinapyl alcohol is a precursor for the lignin biosynthesis

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Fig. 7.2  The cellulose structure. The cellulose is a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units with the formula (C6H10O5) n. The cellulose is an important structural component of the primary cell wall of green plants, many forms of the algae and the oomycetes. Some species of bacteria secrete it to form biofilms. The cellulose content of the cotton fiber is 90%, and that of the wood is 40–50% (Wikipedia)

Presently, the wheat producers and the wheat breeders do not consider breeding wheat with the higher nutritional quality in respect to dietary fiber, anti-oxidants, or methyl donors because no demand has established by the nutritionists, the health authorities and the consumers for these qualities. The wheat growers are mainly interested in the agronomical and the technological properties of the baking while the nutritional functionality of the wheat is rarely considered. The following are the dominant properties make up the so-called technological quality of the wheat, agronomical parameters for maximal yield and profits and 1000-kernel weight, falling number, protein and gluten contents, gluten index (wet gluten), Zeleny sedimentation (a measure for baking quality) or flour extraction rate (Banu and Aprodu 2015). When most of the wheat undergoes refining procedure, the high extraction rate is a major factor in the selection and breeding. This quality increases with 1000 kernel weight but with a decrease in the fiber content and all the essential compounds embedded in the bran.

Fig. 7.3  Metabolites of the hemicelullose (HMDB). (a) 4-O-Methyl-a-D-glucosyl-(1→2)b-D-­xylosyl-(1→4)-D-xylose. (b) 2-O-b-D-Xylopyranosyl-Larabinose is found in cereals and cereal products. (c) 4-O-Methyl-aD-glucosyl-(1→2)-b-D-xylosyl(1→4)-D-xylose is found in cereals and cereal products. 4-O-Methyl-a-D-glucosyl-(1→2)b-D-xylosyl-(1→4)-D-xylose is from oat hull hemicelluloses. (d) Aldobiouronic acid D3 is found in cereals and cereal products. Aldobiouronic acid D3 is isolated from partial acid hydrolysates of gum chagual (Puya species) and the hemicelluloses from corn hulls and wheat bran

The Dietary Fiber Precursors (Building Blocks)

a

CH2OR H

CH2OR

O H OH

H

H

OH

H

H

b

O

O H OH

H

H

OH

OR

CH2OR H

H O

OR O CH2OR

O H OH

H

H

OH

CH2OR H

H

O

OR

O H

O

OH

H

H

OH

O

H

H O

O H OH

H

H

OH

H O

CH2OR O

OR O

OR

CH2OR

OR

CH2OR O

HO

115

O

CH2OR

OH

OR

OR n

Fig. 7.4 The α- and β-glycoside bonds of the glucose polymers. The difference between the two bond-types encircled in red. (a) β-glycoside bonds, cellulose made up of β-glucose bonds. (b) α-glycoside bonds, the starch made up of α-glucose bonds

The Dietary Fiber Precursors (Building Blocks) The dietary fiber made up of several building blocks of the monosaccharides synthesized into long polymers, the connections between the monomers constructed of the two main types of the glycoside bonds namely the α- and the β-configurations (Fig. 7.4). The starch and the disaccharides, like sucrose, constructed of the α-bonds while cell wall ingredients like the cellulose constructed of β-bonds. Since animals and most of the other Eukarya had lost the ability to synthesize enzymes that cleave the β glycoside bond, only α glycoside bonds hydrolyzed in the upper gut of the monogastric animals (Fig. 7.4).

Pentose Pentoses are a monosaccharide with five carbons. Pentoses are organized into two groups: Aldopentoses have an aldehyde functional group at position 1. Ketopentoses have a ketone functional group at position 2 or 3. In the cell, pentoses have higher metabolic stability than hexoses.

Fig. 7.5  Rhamnose, xylose, and arabinose (gray, red and white balls are carbon, oxygen, and hydrogen, respectively) (Wikipedia), shown in two graphical presentations. (a) L-Rhamnose: A methyl-pentose where the L-isomer found naturally in many plant glycosides. (b) Xylose or the wood sugar is an aldopentose - a monosaccharide containing five carbon atoms and an aldehyde functional group. It is 40% as sweet as the sucrose. The xyloses found in the embryos of most edible plants. The polysaccharide xylan closely associated with the cellulose consists practically entirely of the D-xylose. The corncobs, cottonseed hulls, pecan shells, and the straw contain considerable amounts of this sugar. The xylose also found in the mucopolysaccharides of the connective tissues and sometimes in the urine. The xylose is the first sugar added to the serine or the threonine residues during the proteoglycan type O-glycosylation. (c) D-Arabinose found in sweet basil. The arabinose is an aldopentose a monosaccharide containing five carbon atoms, and including an aldehyde (CHO) functional group. The arabinose belongs to the family of the pentoses. (d) L-Arabinose is a pentose with a sweet taste and one of the most abundant components of non-starch polysaccharides of the vegetable origin. A portion of the ingested L-arabinose excreted in the urine. L-arabinose is rarely used, and its physiological effects in vivo have received little attention

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Xylose Xylose is a monosaccharide containing five carbons and an aldehyde functional group. The polysaccharide xylan, which is closely associated with cellulose, consists practically entirely of D-xylose. Xylose found in mucopolysaccharides of the connective tissues and sometimes detected in the urine. Xylose is said to be one of eight essential sugars (must derive from food) for human nutrition, the others being galactose, glucose, mannose, N-acetylglucosamine, N-acetylgalactosamine, fucose, and sialic acid (HMDB). Unlike the cellulose, which made up solely of glucose, the hemicellulose is chemically heterogeneous. Hardwood hemicellulose contains mostly xylans, whereas softwood hemicellulose contains mostly glucomannans. The xylans of many plant materials are heteropolysaccharides with homopolymeric backbone chains of 1,4-linked β-D-xylopyranose units. Besides xylose and xylan, hemicellulose may contain arabinose, glucuronic acid or its 4-O-methyl ether, and acetic, ferulic, and p-coumaric acids (Saha 2003). The extent of the hemicellulose digestion is generally decreasing with the plant maturity and the digestibility varied according to the plant species and varieties.

The Dietary Fiber Polymers Except for the carbohydrates polymers that composing the dietary fiber in the cell wall, the cell wall contains a high content of phenolic acids. The phenolic acids present in the cell wall thought to play an important part in the cross-linking of polysaccharides with other cell-wall components, including lignin through ester and ether bonds, and in the cross-linking of the polysaccharide chains. Ferulic acid was found as the most aboundment polyphenol in the wheat kernel, (Fig. 9.7, Table 8.2), esterified to arabinose units of the cell-wall arabinoxylans (Fig. 7.6). Ferulic acid is prominent in the aleurone, pericarp, and embryo cell walls (Fig. 7.7). The dehydrodiferulic acid moieties have also found in the wheat tissues, as in many other members of the Poaceae. The phenolic-polymer cross-linking may also influence the rate of the degradation of the fiber from the wheat bran by the colonic bacteria, and thus have potentially important consequences concerning the physiological effects of the bran-based dietary fiber content (Parker et  al. 2005; Redgwell and Fischer 2005). The basic chemical structure of the dietary fiber is very important in the sense of nutritional quality. While the α-glycoside bonds cleaved by the small intestine enzymes the β-glycoside bonds might cleaved only by the macrobiotic enzymes existing only in the colon.

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HOH2C OH

H

arabinoxylan

O H 4

α1

H H

O HO

H O H

H

2

HO

β1 O

HO

3

O O 4

H

H

H

H

H O H

H

O H

HO

α1

HO O

2

H

4

β1

H OH

O H H

OH β1

H

O H O

H

α1

H OH

H

HO

H O H

O

HOH2C

OH

H 3

HO

H

4 O

H

H

H

H

OH β1

H

α1

H

HOH2C H

(Standard)

H

HO

H

O

HO

O

CH2OH

O

HO HO

OH

H

OH OH

HO

xylose

arabinose Fig. 7.6 Arabinoxylan

4

5

2

O

1

3

O O

2

1 O

O 5

4

O O

OH OH

OH 3

H3CO OH

Fig. 7.7  The ferulic acid linked to D-xylopyranosyl (Courtin and Delcour 2002). http://www. ethanolproducer.com/article.jsp?article_id=4160

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The Arabinoxylan The arabinoxylan is one of the two pentosans group that divided into arabinogalactan and arabinoxylan. Arabinoxylans and β-glucans are the major components of wheat endosperm cell walls (Philippe et al. 2006). The arabinoxylan has high variability in the content between the wheat lines. In a survey of 210 wheat lines, a range of 24–108  mg arabinoxylan/g dry matter observed (Pritchard et  al. 2011). Arabinoxylan consists of a backbone of β-1,4-D-xylopyranosyl residues with ­randomly linked L-arabinofuranosyl units. The arabinoxylan affects foodstuff attributes and has positive effects on human health. The highest deposits of the arabinoxylan in the grain placed in the outer layer. The arabinoxylan units bound by the covalent and the non-covalent cross-links to the other plant tissue polymers such as lignin, proteins, and cellulose. The arabinoxylans found in all major cereal grains, including rye, wheat, barley, oats, rice, sorghum, maize, millet, as well as in other plants, such as psyllium. Among the common cereal grains, the highest content of arabinoxylans found in rye followed by wheat, barley, oats, rice, and sorghum. The arabinoxylan classified into the water-extractable and the water-unextractable. For human diet, arabinoxylan described as a helpful ingredient to prevent a lot of diseases like diabetes type 2, intestine cancer, and cardiovascular disease. In the colon, arabinoxylan stimulates the growth of probiotic bacteria (Döring et al. 2016). The amount of the attached ferulic acid to the arabinoxylan is small, ranging 0.2–0.4% in case of water-soluble arabinoxylans and 0.6–0.9% for the insoluble ones. This indicates that for every 1000 water-soluble xylose residues, there are 2–4 ferulic units and for 1000 insoluble residues, there are 6–10 units of the ferulic acid (Rosicka-Kaczmarek et al. 2016a). There is considerable interest in modifying the amounts and the compositions of the starch and the major non-starch polysaccharides (arabinoxylan and β-glucan) to develop new types of the cereals with improved health benefits, notably reduced the glycemic index in the small intestine and improved properties of the dietary fiber in the colon. This is achieved by the exploiting genetic variation in the composition with the ability to generate additional variation using mutagenesis and transgenesis. The development and the adoption of such varieties will allow health benefits delivered to large populations in low-cost staple foods such as the bread, noodles, and pasta (Rosicka-Kaczmarek et al. 2016b). The arabinoxylan comprises 6.4% of the kernel of the whole-wheat (8.5% of the rye) Table 6.1. Arabinoxylan comprises a fraction of the dietary fiber as it delivered untouched through the upper gut and fermented in the colon thus used as a major prebiotic source. The arabinoxylan with its flour content, the specific composition with arabinose/xylose ratio, the degree of polymerization and substitution along the backbone has the variable quality of water absorption and a major effect on the baking process and the bread quality.

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The Effect of the Arabinoxylan on the Dough Rising Because of the arabinoxylan properties, such as the high capacity to absorb water, they show a tendency to form high viscosity solutions. This determines their directions of use. The physicochemical properties of the arabinoxylan depend primarily on their molecular structure of the degree and the profile of substitution, as well as the xylose to the arabinose ratio. The arabinoxylans have a major impact on the process of the bread baking and shaping its quality parameters such as the texture or the volume. The addition of the water-soluble arabinoxylans to the wheat dough increases its viscosity and the water absorption as well as extends the time of the development and the kneading the dough. The dose of the pentosan preparation is important, so is the molecular weight of the arabinoxylan contained therein. The addition of the water-extractable arabinoxylan has a significantly positive effect on the bread volume (Rosicka-Kaczmarek et al. 2016a). The ratio of arabinose/xylose is of critical importance to the confirmation and the functionality of the arabinoxylan molecules in the wheat flour. The distribution of the arabinose is nonrandom along the xylose backbone. The structural models indicate that the highly substituted regions contain high proportions of the di-substituted xylose residues along with segments of the contiguously mono-substituted xylose residues, which separated by the segments that are less highly substituted, containing blocks of the unsubstituted xylose molecules. These highly substituted regions hypothesized to be 20–25 residues in length, interrupted by the segments of the ≥5 unsubstituted xylose residues. On the average, the mono-substituted xylose makes up ~21% of all xylose residues, di-substituted xylose residues 13%, and the unsubstituted xylose residues 66%. The majority of the mono-substituted xylose residues contain the arabinose substituted on the 3rd carbon, with only a small percentage of substitution occurring on the 2nd carbon (Kiszonas et al. 2013). Several factors determine the three-dimensional structure of the arabinoxylan: the length of the xylan backbone, the arabinose/xylose ratio, the arabinose substitution pattern, and the ferulic acid coupling to the other arabinoxylan molecules, proteins or to the other cell wall constituents. The 3-dimensional structure influenced by the somewhat flexible nature of the arabinoxylan and their large molecular weight (typically ranging from 30–150 kDa). Despite a generally negative influence of the arabinoxylan on the soft wheat product quality, the water un-extractable arabinoxylan, in particular, considered highly beneficial for bread quality. While the total arabinoxylan (primarily water-unextractable arabinoxylan) has observed to affect adversely the overall bread dough characteristics, a higher proportion of water-unextractable arabinoxylan in total arabinoxylan positively influences the dough characteristics. It was surmised that the negative influence of the total arabinoxylan in the bread can attribute to the water-unextractable arabinoxylan fraction, which tends to decrease bread quality. The arabinoxylan structural characteristics also varied among different bread fractions. The crumb and inner crust contained higher levels of di-substituted arabinoxylan as compared to the flour and the dough (Kiszonas et al. 2015; Garcia et al. 2007).

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Glucomannan A water-soluble polysaccharide that considered as a dietary fiber. It is a hemicellulose component in the cell walls of some plants. Glucomannan is a food additive used as an emulsifier and thickener. Products containing glucomannan, with a variety of brand names marketed as dietary supplements with dietary claims with low evidence support and reported adverse effects (Wikipedia). The content in the wheat flour is quite low but with a significant effect on the dough structure.

The Resistant Starch Resistant starch appears to confer considerable health benefits. Processing conditions and ingredients may influence the formation of the resistant starch in foodstuffs. An extended baking process, storing the bread, modifying the ingredients ratio and the processing conditions may increase the resistant starch content (Amaral et al. 2016). The resistant starch does not comprise the cell wall but come from the endosperm and attached to the digestible starch. The digestibility of resistant starch is more similar to the non-starch polysaccharides than to the digestible starch (Fuentes-Zaragoza et al. 2010). The resistant starch comprises ~13% of the wheat dietary fiber (Table 6.2) and includes the starch portion that resists digestion by the human pancreatic amylase in the small intestine. The resistant starch reaches the colon untouched. The resistant starch is chemically similar to the digestible starch (which is the main kernel fraction) but it fermented only at the lower gut (colon) and has a distinct physiological activity from that of the main starch fraction. With the physiological aspect, resistant starch is a fraction of the dietary fiber. The metabolism of the resistant starch in the colon induces the production of butyrate. The resistant starch helps to control body weight since it prolongs satiety, due to its low energy density, and its ability to undergo fermentation by the colonic bacteria. These bacteria produce short-chain fatty acids that can reduce energy intake (Waterschoot et al. 2015). The food products made from flours with higher amylose content contain a higher content of resistant starch. As with fiber, the increased consumption of resistant starch has associated with reduced risk of diseases. Reduced starch digestion in the small intestine decreases the rate of the glucose entering the bloodstream, which in turn reduces the demand for insulin and lowers the glycemic index of the consumed food. Although the normal amylose content in the wheat grain is relatively low (20–30%), it can increase by downregulating the transcript levels of genes involved in the synthesis of amylopectin since both pathways use adenosine diphosphoglucose as substrate (Hazard et al. 2012). During the food processing, the dietary starch partially undergoes physical modification leading to the formation of the resistant starch that escapes digestion and absorption in the intestine but later ­fermented by the gut microflora. The latter phenomenon is nutritionally beneficial and implied in preventive mechanisms against many intestinal disorders and disease.

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Chemically, the resistant starch derived from the highly retrograded amylose fraction (linear) of starch, and it is that the amount of resistant starch generated is likely proportional to the linear α-glucan content of the starch. The digestibility characteristics of the starch as based foods generally depend on the processing conditions to which they subjected to and the subsequent retro-gradation steps. The latter leads to the rapid development of a network via amylose chain entanglement followed by a slow re-crystallization of the amylopectin chains. Retro-gradation is of primary importance in determining the resistant-starch content of starch (Tharanathan and Tharanathan 2001). While the starch is the main component of the kernel carbohydrates, the resistant starch is a component of the dietary fiber even these two components are very similar in their chemical construction (Sajilata et al. 2006). The amylopectin molecule has a larger proportion of long-chained branches, resulting in a more rigid structure, which is devoid of weak points, thus making the granules of the native starch highly resistant to enzymatic attack (Dupuis et  al. 2014). The starch may become resistant to the digestion due to several reasons, as it may be physically inaccessible, compact granular structure, retrograded or crystalline non-granular, chemically modified or re-polymerized or amylose-lipid complex starches (Almeida et al. 2013).

The Cellulose The cellulose made up of the insoluble microfibrils that have cable-like structures. These structures typically composed of approximately 36 hydrogen-bonded chains containing 500 to 14,000 β-1,4-linked glucose molecules (Fig. 7.2). The cellulose microfibrils comprise the core component of the cell walls that surround each plant cell. Roughly, one-third of the total mass of many plants is cellulose (Somerville 2006). The cellulose is comparatively homogeneous ingredient while its basic building block is the glucose. In human, the colon microbiota degrading and utilizing some amount of the cellulose into short-chain fatty acids (SCFA, up to six carbons long) and other compounds. The ruminants, Equidae, and other herbivores are hosting microbiota with a higher capability to degrade the cellulose.

The Hemicellulose The hemicellulose is a cell component in the plant which becomes soluble dilute alkali or in hot dilute mineral acids with the formation of simple sugars. The hemicelluloses constitute about one-fourth of perennial plants and about one-third of annual plants. Hemicellulose is a group of complex carbohydrates that, with other carbohydrates (such as pectin), surround the cellulose fibers of the plant cell. The most common hemicelluloses contain the polymers of the pentoses xylans (a polymer of the 5-carbon sugar xylose that linked together) and the arabinose polymers,

The Dietary Fiber Polymers

MW 194.1

123

C6H10O7

Fig. 7.8  Glucuronic acid is a typical building block of the hemicellulose precursor (gray, red and white balls are carbon, oxygen, and hydrogen, respectively) (Wikipedia), shown in two graphical presentations. The glucuronic acid is a carboxylic acid that has the structure of a glucose molecule that has had its 6th carbon atom oxidized. The glucuronic salts termed glucuronates. In the animal body, the glucuronic acid often linked to poisonous substances to allow for subsequent elimination, and to hormones to allow for easier transport.

uronic acids (such as glucuronic acid, Fig. 7.8) and hexoses (such as mannose, glucose, and galactose). Beside the hemicellulose is the second most abundant polysaccharide in the terrestrial compounds it has no chemical relationship to cellulose (Saha 2003). In the wheat, the pentosans are the major components of hemicellulosic polysaccharides and are associated with the cell wall fragments with other components, including cellulose, β-glucan, glycoproteins, and the polyphenols. The pentosans play an important role in the dough rheology and the bread quality because of their remarkable functional properties. They exhibit a high affinity for the water and are partly responsible for the high water absorption and the dough viscosity. They also used adhesives, thickeners, stabilizers, and emulsifiers. Depending on the sequence of extraction, the hemicelluloses categorized as hemicelluloses A, B and C, which vary in their sugar composition, physical and functional properties. Structural features of the pentosans, also known as arabinoxylans, vary significantly in different cereals. They consist of a backbone of the 1-4-linked β-D-xylopyranosyl residues to which α-L-arabinofuranose units linked as side branches. Although arabinoxylans from various cereals share the same basic chemical structure, they differ in the way of substitution of the arabinose residues to the xylose backbone. The main differences found in the ratio of arabinose to xylose, in the relative proportions and sequence of various linkages between these two sugars and in the presence of other substituents, such as glucuronic acid and ferulic acid (Revanappa et al. 2010). Some non-cellulosic polysaccharides have historically grouped into the class of hemicelluloses. The hemicellulose does not refer to specific structures in the wall but often synonymous with polysaccharides that can only extract from walls by strong agents such as alkali. Most hemicelluloses are easily extractable with water when they occur outside of a cell wall. The hemicelluloses constitute roughly one-­

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third of the wall biomass and encompass the hetero-mannans, xyloglucan, hetero-­ xylans, and mixed-linkage glucan. The fine structure of these polysaccharides, particularly their substitution, varies depending on the plant species and tissue type (Pauly et al. 2013). The major hemicellulose polymers in cereals are heteroxylans (Hromádková et al. 2008).

The Unique Building Blocks of the Lignin The lignin is one of the three major constituents of the vascular plants, the other two being the cellulose and the hemicelluloses. The lignin term derived from the Latin word lignum that meaning wood. After the cellulose, the lignin is the most abundant natural and surface terrestrial organic polymer. The lignin is phenolic polymeric stuff in the woody cell walls of the plant and produced by a metabolic pathway that exists only in the land plants. As plants evolved into the tall upright form, hundreds of millions years ago, this pathway evolved to produce lignin that reinforces the cell walls of the plant to provide the means to conduct water from the roots to the leaves. After cell growth has ceased, the lignin is formed by a dehydrogenative polymerization of the 3 p-hydroxycinnamyl alcohols (monolignols, coumaryl, coniferyl, and sinapyl alcohol), which are formed from D-glucose via the shikimic acid pathway (Saake and Lehnen 2007). Lignins are complex phenolic polymers that generated through radical polymerization of phenolic compounds, especially the monolignols p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol (Fig. 7.4). Other compounds such as phenolic acids partially incorporated into the lignin polymer. The most important reactions are coupling reactions between the lignin monomers and the growing polymer, predominantly resulting in two types of linkages, β-O-4-linkages, and to a lesser degree, β-5-linkages. The β-O-4-ether linkage, which usually represents >50% and often >80% of the linkages, and other common linkage types in natural the lignins are stable against most chemical treatments, explaining the high resistance of the lignin against chemical degradation. Lignin can reduce the fermentability of the cell wall polysaccharides by human gut bacteria and prolong fermentation (Bunzel et  al. 2011). Some of the typical precursors of the lignin building blocks shown in Fig. 7.1. The lignin (Fig.  7.9) almost not decomposed by the microbiota of the human colon. However, it has the most important role in colon fermentation. Efficient fermentation of the fermentable dietary fiber must be supported by the non-­fermentable dietary fiber that mainly contains lignin. The lignin supports the colon microbiota and thus enables the microorganisms to digest the fermentable fraction. The attack of the cellulose by the bacteria and by other microorganisms undergoes mainly by the extracellular fermentation and not by the ingestion of the food particles by the microbiota. An example of a possible lignin structure. The portion shown here has 28 monomers (mostly coniferyl alcohol), 278 carbon atoms, 407 hydrogen atoms, and 94

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125

Fig. 7.9  Scheme of the lignin structure (Wikipedia).

oxygen atoms (64% carbon, 8% hydrogen, and 29% oxygen by weight) which seems to be too high in hydrogen. Without the physical support of the rigid unfermented dietary fiber, the microbiota sailing freely unbounded in the digesta-fluid and any cellulolytic enzyme excreted outside the bacterium cell diluted immediately which resulted in a very low enzymatic activity. However, when the bacterium bounds to a rigid support (the non-fermentable dietary fiber) the enzymes excreted outside the bacterium and stay at the vicinity of the bacterium enable the decomposition of the cellulose nearby the bacterium cell. The lignin is the most resistant vegetal fraction to the attack of the microbiota enzymes. Most of all of the lignin molecules fall into the definition of non-­ fermentable dietary fiber. Some of the lignin phenolic compounds exert vital anti-­ oxidant activity.

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The Uronic Acids The uronic acids defined as aldoses of which the primary alcohol oxidized to a carboxylic acid function. They are widespread in nature, where they constitute key components of the oligo- and the polysaccharides and the glycoconjugates found in all life forms. As such, they play a role in numerous biological processes and therefore the synthesis of the uronic acid-containing oligosaccharides and glycoconjugates has received considerable attention from the synthetic organic chemistry community (Codee et al. 2011). The names of uronic acids are generally based on their parent sugars, for example, the uronic acid analog of glucose is glucuronic acid. Uronic acids derived from hexoses are known as hexuronic acids and uronic acids derived from pentoses are known as penturonic acids. Some of these compounds have important biochemical functions; for example, many wastes in the human body are excreted in the urine as their glucuronate salts, and iduronic acid is a component of some structural complexes such as proteoglycans.

Iduronic Acid Iduronic acid is a constituent of glycosaminoglycans heparin and heparan sulfate in varying proportions providing considerable diversity in sequence and biological function (Fig. 7.10). The glycosaminoglycans are linear polysaccharides with alternating uronic acids (iduronic acid and glucuronic acid) and hexosamine residues, in which a limited set of monosaccharide units gives rise to many complex sequences by variable substitution with O-sulfate, N-sulfate, and N-acetyl groups (HMDB).

The Lignocellulose The lignocellulose substances constituting the essential part of the cell wall of the plants with the three main components: (a) The cellulose with the β-(1–4)-linked chain of the glucose molecules and with the hydrogen bonds between the different layers of the polysaccharides that contribute to the resistance of the crystalline cellulose against degradation. (b) The hemicellulose, the second most abundant component of the lignocellulose, composed of various 5- and 6-carbon sugars such as arabinose, galactose, glucose, mannose, and xylose. (c) The lignin that mainly composed of the three major phenolic components, namely p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol; the lignin synthesized by the polymerization of these components. Their ratio within the polymer varies between different plants, wood tissues, and cell wall layers. The

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The Inulin

MW 194 C6H10O7 Fig. 7.10  Iduronic acid

cellulose, the hemicellulose, and the lignin form the structures called the ­microfibrils, which organized into the macrofibrils that mediate the structural stability in the plant cell wall (Rubin 2008; Shirkavand et al. 2016). The lignocellulose is a part of the lignin component of the food materials. Commonly, no quantitative definition of the lignocellulose fraction specified and has a small kernel content but with the higher straw content. The two polymers, the cellulose, and the hemicellulose are physically encrusted with the lignin, to which they covalently linked through the lignin-saccharide bonds that provide mechanical strength and rigidity to the plant tissues. In-plant cell walls, monophenolic compounds such as p-coumaric and ferulic acids are known to link arabinoxylans to lignin via ester bonds (Trigo and Ball 1994).

The Inulin The inulin is a mixture of fructose chains (2–60 units) that vary in length and typically have a terminal glucose molecule (Fig. 7.11). The inulin is a natural storage carbohydrate in several edible plants including chicory, artichoke, leek, onion, asparagus, wheat, barley, rye, garlic, and bananas. The bond between the fructose units in inulin is a β-(2–1) glycosidic linkage. The inulin sometimes added to the food products because of its sweet taste and texture. The American diets typically provide about 2.6  g/d of inulin, with wheat (69%) and onions (23%) being the ­primary sources. The inulin is a preferred food for probiotics. When subjects were given 15 g/d of inulin, the colon population of the bifidobacteria increased by about 10% and the populations of the pathogenic bacteria decreased. The bifidobacteria digest inulin to produce the short-chain fatty acids, such as acetic, propionic, and butyric acids. Acetic and propionic acids serve as the energy sources for the liver, while butyric acid has cancer-preventing properties in the colon. The inulin facilitates the absorption of the calcium, magnesium, and iron in the colon due to the formation of the short-chain fatty acids, acetic, propionic, and butyric acids. High concentrations of calcium may aid the formation of insoluble bile or salts of the fatty acids and therefore may reduce the damaging effects of the bile or the fatty acids on colonocytes.

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Fig. 7.11  The inulin is a soluble dietary fiber. It is a naturally occurring oligosaccharide composed mainly of the fructans. The non-digestible inulin passes through the small intestine and fermented in the colon. The plant inulins contain between 20 to several thousand fructose units. Inulin is naturally present in many foods. Chicory root is the most common source of the inulin due to its extremely high concentration as well as its similarities to the sugar beet. Inulin has several health benefits. This dietary fiber used as a prebiotic agent in functional foods to stimulate the growth of beneficial intestinal bacteria (HMDB)

The Energy Extraction from the Dietary Fiber by the Colon The energy yield for human metabolism extracted from the dietary fiber is quite low because of the high content of the non-fermentable fraction presented in the digesta and because of a considerable portion of the energy released on fermentation diverted to sustain the metabolism of the microbiota. The energy consumed by the microbial metabolism increases body temperature but without contributing to the

The dietary fiber is only one of the wheat kernel components and comprises 12% of the total content (Table 6.1) with only some 8% of the total energy extracted from the whole-wheat flour. Most of the energy extracted in the colon from the dietary fiber wasted as heat and does not transform through human physiologic cycles. Even so, we detailed precisely all the dietary fiber qualities and tried to collect any available classification. The dietary fiber of the whole-wheat (comprises about half of the total intake of the dietary fiber) is the main pillar of the uncounted colon activities which acquires the whole-­wheat its particular effect on the human health. The bottom line of such a­ ctivities is the summary of Table 15.1 that describes the decrease in the relative risk for morbidity and mortality emitted by the whole-flour. Even after we will consider in detail all the ingredients, we still

The Energy Extraction from the Dietary Fiber by the Colon

129

not know how each ingredient shares his activity in the reduction of the relative risks of the health burdens. The human mind requires a strict definition of the food ingredients to organize properly his opinion, knowledge, and attitude about the hundreds of dietary items. The vitamin is the finest example to show the severe difficulty in the strict definition of the term vitamin and in particular, the vitamins present in the whole-­bread. The whole-wheat bread contains presumably hundreds of compounds related to the vitamin term (including all the polyphenols derivatives) that according to the classical definition are not defined vitamin but they are crucial for human longevity and to the shorter years of disability on aging.

chemical and the physiological activity of the cellular host. In a cold environment, the microbial energy contributes to preserving the body temperature but in the hot or even temperate temperature, it has only a negative outcome for human physiology. Besides, some of the energy of the dietary fiber emitted into the atmosphere by the microbiota activity as molecular hydrogen and methane. Archaea, comprising part of our colon microbiota, are the only microbiota known to produce methane. In the ruminants, they may account for 3% of all microbiota genome and in human, probably a lower number is present (Lange et al. 2005). The hydrogen and the methane contain concentrated energy but without any contribution to the microbiota metabolism and no contribution to human physiology. Human individuals differ in their tendency to produce high or low methane volume (Robert and Bernalier-­ Donadille 2003). The differences between the individuals may produce by the variable microbiota population that is highly affected by the bile concentration in the colon and the hydroxylation reaction they undergo (Singh et al. 2019). Thus, the energy released in the colon from the inulin products or FOS (fructose oligosaccharide) (Fig. 7.12) contains 2 kcal/g, which is about half of that released from digestible carbohydrates absorbed from the upper gut (Cherbut 2006). Energetically as an organ, the colon efficiency is very low, while the colon accounts for 17% of the total gut volume it supplies less than 10% of the energy available for cellular activities of the host (Flint 2004). Energetically, the maintenance of the large colon with its devastating energy utilization is a major burden in the human physiology. Such an energy dispersion organ has a particular burden in the human that must maintain a large brain that disperses ~25% of the whole-energy production at rest. To preserve the ability of the microbiota to populate human colon and to interact efficiently with the immune system, the human needs a sufficient amount of the fermentable dietary fiber to support the microbiota metabolism. Besides the energy supplied by the fermentable dietary fiber, human also needs non-fermentable dietary fiber to support the microbiota cells activity. Even the Inuit (Eskimo) people contained a considerable amount of dietary fiber of ~18  g/d for adults (Nobmann et al. 2005). Misconception widely prevails for the effect of the whole-wheat intake on the human physiology.

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HOCH2

O

H O

H HO

CH2

O

H O CH2OH H H HO

O

OH

H

H

OH

H O

H HO

O

H OH

CH2OH

H

OH

CH2

CH2OH

H

OH

n H

HO

CH2OH

H

Fig. 7.12  The fructooligosaccharides (FOS) considered as one of the main group of the prebiotics that has recognized as bifidogenic properties. The FOSs are obtained either by the extraction from various plant materials or by the enzymatic synthesis from different substrates. Enzymatically, these can obtain either from the sucrose using fructosyltransferase or from inulin by the endoinulinase. The inulin is a potent substrate for the enzymatic production of the FOSs (Singh et al. 2016)

The Evaluation of the Nutritive Quality of the Dietary Fiber The effect of the whole-wheat intake on the human physiology has severely misconception because of the dietary fiber claimed as the sole or the major ingredient responsible for the nutritional advantage of the whole-wheat. Even the dietary fiber of the wheat kernel has an important role in the health alleviative effects of the whole-wheat intake, some other ingredients have also a marked contribution that occasionally ignored. The vast majority of the kernel dietary fiber located at the outer kernel layers. But, except for the dietary fiber, these kernel tissues contain most of the kernel anti-oxidant compounds and many other micro-ingredients. Because that no distinction can show the discrete activity of every ingredient, nobody knows the specific activity of the dietary fiber on the colon microbiota or any other physiological phenomenon. With the advance of the understanding of the crucial role of the whole-wheat intake in the sensible nutrition, the dietary fiber considered as the major or the sole ingredient that responsible for the nutritional advantage of the whole-wheat, presumably because of its total mass weighs many folds the total mass of all the other ingredients. Such an approach has exemplified in the publication list cited directly and indirectly in (Table 15.1). While in many of the articles the effect of the whole-grain intake has fairly presented as the physiological reason in moderating the relative risk of mortality or morbidity, in many other studies the dietary fiber considered as almost the sole ingredient responsible for the alleviative outcome without mention the role of the other ingredients. Such a misconception ignores almost thoroughly

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131

the role of the micronutrients and in particular the role of the polyphenols and other micronutrients that encourage the alleviation in the physiological activities. Such an approach has a seriously deleterious effect because it led commercial enterprises to supply isolated dietary fiber for the bread doughs and other food ­products pretending to exert beneficiary activity as for the effect of the wholewheat. Because no distinction can be made between the dietary fiber and all of the minor- and micro- nutrients present in the wheat kernel the evaluation of wholewheat quality should perform only by the physiological criteria and not according to the chemical analyses. Digestion experimentation (conducted mostly in rats or mice), well reflect the biochemical activities of the upper gut in the human. However, in the colon, the activity is quite different between human and the experimental animals because of the colon structure and because of the marked differences in the transition time of the digesta, because of the colon relative capacity, and because of the difference in microbiota population. Because of the digesta decomposition in the colon almost undergoes by the microbiota such activity defined as fermentation rather than digestion. The fermentability studies for the evaluation of the isolated ingredients of the dietary fiber in human or even in animal models are difficult to perform. The hydrogen excretion methodology is commonly used for the evaluation of the fermentability scale because the excreted hydrogen produced only by the colon microbiota and not in the upper gut. However, although the hydrogen measurement is quantitative for the oligosaccharides, it is only qualitative for insoluble or slowly fermented substrates (Champ et al. 2004). While the energy yield of the dietary fiber has a minor impact on the total balance of the energy production, the effect of the dietary fiber on the microbiota activity and the microbiota population has a major role in the human wellbeing. The maintenance of the microbial population in the colon (1014 to 1015 total cell number and also 10 phages in a microbe), enables the dietary fiber to induce the interaction between the gut structure with the immune system. In Western Societies, most people consume protein at a reasonable quality and quantity or presumably above the required amount. The carbohydrates and fat generally consumed excessively. However, dietary fiber mostly consumed insufficiently. The dietary fiber is the most heterogeneous nutrient and its specific composition has a major role in its activity. Because only small part of the polyphenol mass in the wheat kernel present as free compounds, while the main polyphenols of the wheat kernel bounded to the dietary fiber, most of the polyphenols released in the colon, and thus the dietary fiber cannot be evaluated separately as an isolated ingredient. Animal experimentation is the most common methodology for the investigation of the majority of the nutritional effects and ingredients. Such a methodology is most tempting to be used for the dietary fiber and many studies have published by such a methodology. Because of the severe limitations discussed here, we wonder how relevant are the conclusions of these animal studies for human nutrition. The common wheat (Triticum aestivum was also known as the winter and the spring wheat) is the most important cereal crop worldwide. It contains dietary fiber

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at a normal range of 11–18%, whereas other wheat grains contain a wider range of 7–22% (Gebruers et al. 2008). The possibility of replacing the whole-wheat products for other/s cereal is often sounded by many people and in particular by those with celiac disease or other wheat intolerances. The main substitutes for the whole-wheat might be rye, oat, and corn. The comparison of the total phenol for wheat, rye, oat, and corn shows average content, μg/g (with the number of the varieties detected) of wheat 660 (150), rye 460 (10), oats 320 (5), and corn 2600 (Table 9.2). Rye consumed as a staple food in many areas. Since it generally consumed as a whole-grain product it might be a good substitution for the wheat. However, as for wheat barley and rye are also have permanent intolerance to the gliadin (a part of the gluten). Some individuals with celiac disease also sensitive to oats but there are claims for the oat varieties free of such inducer of the sensitivity (McGough and Cummings 2005). Still, a question sound by many people, can the whole-bread rye might have the same health alleviative outcome as for the whole-wheat. Unfortunately, no clear-cut is available for such a simple question. Currently, the present global rye production is only ~1.5% of that of the wheat (Table 1.2). The dietary fiber content of the rye kernel is some higher than that of the wheat, 15 vs 12% (Table 3.4). The polyphenol content of the rye is somewhat lower 460 vs 660 μg/g. However, the information for the alleviative effect based on human extensive epidemiological studies has widely shown for the wheat (Table 15.1) but not for the rye.

The Dietary Fiber Digestion in the Herbivores Human ferments only a minor portion of all cellulose digestion. Within the mammals, ruminants are the well-known animals as cellulose digesters that also combust and utilize acetate and the other short-chain fatty acids derived from the fermentation of the cellulose and the other dietary fiber ingredients. With their high rumen and intestinal capacities, ruminants and some other genera may utilize plant cell-­wall constituents employing their gut microbiota symbionts. Such a strategy of energy accomplishment enables herbivores (including many wild animals, termites, and other insects) to utilize a very wide span of energy resources (and nitrogen and vitamins) but with lower energy efficiency than the energy extracted from food by monogastric animals. Human has also gut symbionts but with a lower fermentation efficiency than that of the ruminants. The fermentation compartment of the ruminants and the other herbivorous animals contains a broad range of microorganisms phyla namely bacteria, archaea, protozoa, fungi and yeast (Miron et al. 2010). The multi-hundreds microorganism species present in the rumen contain more than 1000 degrading enzymes of glycoside bonds that split the polysaccharide polymers (Flint 2004). The maintenance and the survival of herbivorous are thoroughly dependent on the fermentative activity of their inner symbionts. Evolutionary, the human could not survive and compete against other

References

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species without acquiring some of his diets by animal products because he must maintain his large brain the peculiar organ, with huge energy consumption with the extraction efficiency.

References Almeida EL, Chang YK, Steel CJ (2013) Dietary fibre sources in bread: influence on technological quality. LWT-Food Sci Technol 50:545–553. https://doi.org/10.1016/j.lwt.2012.08.012 Amaral O, Guerreiro CS, Gomes A, Cravo M (2016) Resistant starch production in wheat bread: effect of ingredients, baking conditions and storage. Eur Food Res Technol 242:1747–1753. https://doi.org/10.1007/s00217-016-2674-4 American Association of Cereal Chemists - AACC (2001) Report of the Dietary Fiber Definition Committee to the Board of Directors of the AACC. Publication no. W-2001-0222-01O. http:// www.aaccnet.org/initiatives/definitions/Documents/DietaryFiber/DFDef.pdf Asp NG, Björck I, Nyman M (1993) Physiological effects of cereal dietary fibre. Carbohydr Polym 21:183–187. https://doi.org/10.1016/0144-8617(93)90016-W Aust L, Dongowski G, Frenz U, Täufel A, Noack R (2001) Estimation of available energy of dietary fibres by indirect calorimetry in rats. Eur J Nutr 40:23–29. https://doi.org/10.1007/ PL00007382 Banu I, Aprodu I (2015) Association of physicochemical with technological properties of wheat. Int J Food Sci Technol 50:1644–1650. https://doi.org/10.1111/ijfs.12816 Brownlee I, Dettmar P, Strugala V, Pearson J (2006) The interaction of dietary fibres with the colon. Curr Nutr Food Sci 2:243–264. https://doi.org/10.2174/157340106778017896 Bunzel M, Schüsler A, Tchetseubu SG (2011) Chemical characterization of Klason lignin preparations from plant-based foods. J Agric Food Chem 59:12506–12513. https://doi.org/10.1021/ jf2031378 Champ M, Langkilde A-M, Brouns F, Kettlitz B, Collet YLB (2003) Advances in dietary fibre characterisation. 1. Definition of dietary fibre, physiological relevance, health benefits and analytical aspects. Nutr Res Rev 16:71–82. https://doi.org/10.1079/NRR200254 Champ M, Langkilde A-M, Brouns F, Kettlitz B, Bail-Collet YL (2004) Advances in dietary fibre characterisation. 2. Consumption, chemistry, physiology and measurement of resistant starch; implications for health and food labelling. Nutr Res Rev 16:143. https://doi.org/10.1079/ nrr200364 Cherbut C (2006) Inulin and oligofructose in the dietary fibre concept. Br J Nutr 87:S159–S162. https://doi.org/10.1079/bjn2002532 Codee JDC, Christina AE, Walvoort MTC, Overkleeft HS, Marel GAVD (2011) Uronic acids in oligosaccharide and glycoconjugate synthesis. In: Fraser RB, Lopez JC (eds) Reactivity tuning in oligosaccharide assembly. Top Curr Chem 301: 253–289. Springer, Berlin, Heidelberg. https://doi.org/10.1007/128_2010_111 Courtin CM, Delcour JA (2002) Arabinoxylans and endoxylanases in wheat flour bread-making. J Cereal Sci 35:225–243. https://doi.org/10.1006/jcrs.2001.0433 Davies IR, Brown JC, Livesey G (2005) Energy values and energy balance in rats fed on supplements of guar gum or cellulose. Br J Nutr 65:415. https://doi.org/10.1079/bjn19910101 Döring C, Jekle M, Becker T (2016) Technological and analytical methods for arabinoxylan quantification from cereals. Crit Rev Food Sci Nutr 56:999–1011. https://doi.org/10.1080/104083 98.2012.749207 Dupuis JH, Liu Q, Yada RY (2014) Methodologies for increasing the resistant starch content of food starches: a review. Compr Rev Food Sci Food Saf 13:1219–1234. https://doi. org/10.1111/1541-4337.12104 Flint HJ (2004) Polysaccharide breakdown by anaerobic microorganisms inhabiting the mammalian gut. Adv Appl Microbiol 56:89–120. https://doi.org/10.1016/S0065-2164(04)56003-3

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7  The Dietary Fiber

Fuentes-Zaragoza E, Riquelme-Navarrete MJ, Sánchez-Zapata E, Pérez-Álvarez JA (2010) Resistant starch as functional ingredient: a review. Food Res Int 43:931–942. https://doi. org/10.1016/j.foodres.2010.02.004 Garcia AL, Otto B, Reich SC, Weickert MO, Steiniger J, Machowetz A, Rudovich NN, Möhlig M, Katz N, Speth M, Meuser F, Doerfer J, Zunft HJF, Pfeiffer AHF, Koebnick C (2007) Arabinoxylan consumption decreases postprandial serum glucose, serum insulin and plasma total ghrelin response in subjects with impaired glucose tolerance. Eur J Clin Nutr 61:334–341. https://doi.org/10.1038/sj.ejcn.1602525 Gebruers K, Dornez E, Boros D, Fraś A, Dynkowska W, Bedo Z, Rakszegi M, Delcour JA, Courtin CM (2008) Variation in the content of dietary fiber and components thereof in wheats in the healthgrain diversity screen. J Agric Food Chem 56:9740–9749. https://doi.org/10.1021/ jf800975w Hazard B, Zhang X, Colasuonno P, Uauy C, Beckles DM, Dubcovsky J (2012) Induced mutations in the starch branching enzyme II (SBEII) genes increase amylose and resistant starch content in durum wheat. Crop Sci 52:1754–1766. https://doi.org/10.2135/cropsci2012.02.0126 HMDB. http://www.hmdb.ca/hml Hromádková Z, Košt’álová Z, Ebringerová A (2008) Comparison of conventional and ultrasound-­ assisted extraction of phenolics-rich heteroxylans from wheat bran. Ultrason Sonochem 15:1062–1068. https://doi.org/10.1016/j.ultsonch.2008.04.008 Johnson IT (2012) Chap 8: Dietary fiber. In: Erdman JW Jr, Macdonald IA, Zeisel SH (eds) Present knowledge in nutrition, 10th edn. ILSI/Wiley-Blackwell, Washington, DC, pp 97–117 Kiszonas AM, Fuerst EP, Morris CF (2013) Wheat arabinoxylan structure provides insight into function. Cereal Chem 90:387–395. https://doi.org/10.1094/CCHEM-02-13-0025-FI Kiszonas AM, Fuerst EP, Luthria D, Morris CF (2015) Arabinoxylan content and characterisation throughout the bread-baking process. Int J Food Sci Technol 50:1911–1921. https://doi. org/10.1111/ijfs.12829 Lange M, Westermann P, Ahring BK (2005) Archaea in protozoa and metazoa. Appl Microbiol Biotechnol 66:465–474. https://doi.org/10.1007/s00253-004-1790-4 Liu RH, Adom KK (2007) Whole-grain phytochemicals and antioxidant activity. In: Marquart L, Jacobs DR, GH MI, Poutanen K, Reicks M (eds) Whole-grains and health. Blackwell, Ames, pp 185–208 Lupton JR (2012) From basic science to dietary guidance: dietary fiber as an example. J Food Drug Anal 20:346–349 Lupton JR, Brooks GA, Butte NF, Caballero B, Flatt JP, Fried SK, Garlick PJ, Grundy SM, Innis SM, Jenkins DJA, Krauss RM, Kris-Etherton P, Lichtenstein AH, Nuttall FQ, Pencharz PB, Pi-Sunyer FX, Rand WM, Reeds PJ, Rimm EB, Roberts SB (2002) Chap 7: Dietary, functional and total fiber. In: Dietary reference intake for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. Institute of Medicine, National Academies, Washington, DC, pp 339–421 Lupton JR, Betteridge VA, Pijls LTJ (2009) Codex final definition of dietary fibre: issues of implementation. Qual Assur Saf Crop Foods 1:206–212. https://doi.org/10.1111/ j.1757-37X.2009.00043.x McGough N, Cummings JH (2005) Coeliac disease: a diverse clinical syndrome caused by intolerance of wheat, barley and rye. Proc Nutr Soc 64:434–450. https://doi.org/10.1079/pns2005461 Miron J, Ben-Ghedalia D, Morrison M (2010) Invited review: adhesion mechanisms of rumen cellulolytic bacteria. J Dairy Sci 84:1294–1309. https://doi.org/10.3168/jds.s0022-0302(01)70159-2 Nobmann ED, Ponce R, Mattil C, Devereux R, Dyke B, Ebbesson SOE, Laston S, Maccluer J, Robbins D, Romenesko T, Ruotolo G, Wenger CR, Howard BV (2005) Dietary intakes vary with age among Eskimo adults of Northwest Alaska in the GOCADAN study, 2000–2003. J Nutr 135:856–862 Parker ML, Ng A, Waldron KW (2005) The phenolic acid and polysaccharide composition of cell walls of bran layers of mature wheat (Triticum aestivum L. cv. Avalon) grains. J Sci Food Agric 85:2539–2547. https://doi.org/10.1002/jsfa.2304

References

135

Pauly M, Gille S, Liu L, Mansoori N, de Souza A, Schultink A, Xiong G (2013) Hemicellulose biosynthesis. Planta 238:627–642. https://doi.org/10.1007/s00425-013-1921-1 Philippe S, Saulnier L, Guillon F (2006) Arabinoxylan and (1 → 3),(1 → 4)-β-glucan deposition in cell walls during wheat endosperm development. Planta 224:449–461. https://doi.org/10.1007/ s00425-005-0209-5 Poutanen KS, Dussort P, Erkner A, Fiszman S, Karnik K, Kristensen M, Marsaux CFM, Miquel-­ Kergoat S, Pentikäinen SP, Putz P, Slavin JL, Steinert RE, Mela DJ (2017) A review of the characteristics of dietary fibers relevant to appetite and energy intake outcomes in human intervention trials. Am J Clin Nutr 106:747–754. https://doi.org/10.3945/ajcn.117.157172 Poutanen KS, Fiszman S, Marsaux CFM, Pentikäinen SP, Steinert RE, Mela DJ (2018) Recommendations for characterization and reporting of dietary fibers in nutrition research. Am J Clin Nutr 108:437–444. https://doi.org/10.1093/ajcn/nqy095 Pritchard JR, Lawrence GJ, Larroque O, Li Z, Laidlaw HKC, Morell MK, Rahman S (2011) A survey of β-glucan and arabinoxylan content in wheat. J Sci Food Agric 91:1298–1303. https:// doi.org/10.1002/jsfa.4316 Redgwell RJ, Fischer M (2005) Dietary fiber as a versatile food component: an industrial perspective. Mol Nutr Food Res 49:521–535. https://doi.org/10.1002/mnfr.200500028 Revanappa SB, Nandini CD, Salimath PV (2010) Structural characterisation of pentosans from hemicellulose B of wheat varieties with varying chapati-making quality. Food Chem 119:27– 33. https://doi.org/10.1016/j.foodchem.2009.04.064 Richie JP, Muscat J (2015) Response to letter to the editor from Dr. Guilford. Eur J Nutr 54:861– 861. https://doi.org/10.1007/s00394-015-0873-6 Robert C, Bernalier-Donadille A (2003) The cellulolytic microflora of the human colon: evidence of microcrystalline cellulose-degrading bacteria in methane-excreting subjects. FEMS Microbiol Ecol 46:81–89. https://doi.org/10.1016/S0168-6496(03)00207-1 Rosicka-Kaczmarek J, Komisarczyk A, Nebesny E, Makowski B (2016a) The influence of arabinoxylans on the quality of grain industry products. Eur Food Res Technol 242:295–303. https:// doi.org/10.1007/s00217-015-2549-0 Rosicka-Kaczmarek J, Makowski B, Nebesny E, Tkaczyk M, Komisarczyk A, Nita Z (2016b) Composition and thermodynamic properties of starches from facultative wheat varieties. Food Hydrocoll 54:66–76. https://doi.org/10.1016/j.foodhyd.2015.09.014 Rubin EM (2008) Genomics of cellulosic biofuels. Nature 454:841–845. https://doi.org/10.1038/ nature07190 Saake B, Lehnen R (2007) Lignin. In: Elvers (ed) Ullmann’s Encyclopedia of industrial chemistry. Wiley-VCH, Weinheim. https://doi.org/10.1002/14356007.a15_305.pub3 Saha BC (2003) Hemicellulose bioconversion. J Ind Microbiol Biotechnol 30:279–291. https:// doi.org/10.1007/s10295-003-0049-x Sajilata MG, Singhal RS, Kulkarni PR (2006) Starch - a review. Compr Rev Food Sci Food Saf 5:1–17 Shirkavand E, Baroutian S, Gapes DJ, Young BR (2016) Combination of fungal and physicochemical processes for lignocellulosic biomass pretreatment - a review. Renew Sust Energ Rev 54:217–234. https://doi.org/10.1016/j.rser.2015.10.003 Singh RS, Singh RP, Kennedy JF (2016) Recent insights in enzymatic synthesis of fructooligosaccharides from inulin. Int J Biol Macromol 85:565–572. https://doi.org/10.1016/j. ijbiomac.2016.01.026 Singh J, Metrani R, Shivanagoudra SR, Jayaprakasha GK, Patil BS (2019) Review on bile acids: effects of the gut microbiome, interactions with dietary fiber, and alterations in the bioaccessibility of bioactive compounds. J Agric Food Chem 67:9124–9138. https://doi.org/10.1021/ acs.jafc.8b07306 Somerville C (2006) Cellulose synthesis in higher plants. Annu Rev Cell Dev Biol 22:53–78. https://doi.org/10.1146/annurev.cellbio.22.022206.160206 Spiller GA (2001) Dietary fiber in human nutrition dietary fiber in human nutrition. CRC handbook of dietary fiber in human nutrition, 3rd edn. CRC Press, Boca Raton

136

7  The Dietary Fiber

Stephen AM, Champ MMJ, Cloran SJ, Fleith M, Van Lieshout L, Mejborn H, Burley VJ (2017) Dietary fibre in Europe: current state of knowledge on definitions, sources, recommendations, intakes and relationships to health. Nutr Res Rev 30:149–190. https://doi.org/10.1017/ S095442241700004X Sun J, Chu YF, Wu X, Liu RH (2002) Antioxidant and antiproliferative activities of common fruits. J Agric Food Chem 50:7449–7454. https://doi.org/10.1021/jf0207530 Tharanathan M, Tharanathan RN (2001) Resistant starch in wheat-based products: isolation and characterisation. J Cereal Sci 34:73–84. https://doi.org/10.1006/jcrs.2000.0383 Trigo C, Ball AS (1994) Is the solubilized product from the degradation of lignocellulose by actinomycetes a precursor of humic substances? Microbiology 140:3145–3152. https://doi. org/10.1099/13500872-140-11-3145 Waterschoot J, Gomand SV, Fierens E, Delcour JA (2015) Production, structure, physicochemical and functional properties of maize, cassava, wheat, potato and rice starches. Starch 67:14–29. https://doi.org/10.1002/star.201300238 Wikipedia. https://www.wikipedia.org/ World Health Organization (2003) Diet, nutrition and the prevention of chronic diseases: report of a joint WHO/FAO expert consultation, Geneva, 2002. WHO Technical Report Series 149

Chapter 8

The Vitamins and the Organic Micronutrients in the Wheat Kernel

The human mind requires a strict definition for the food ingredients to organize properly his opinion, knowledge, and attitude about hundreds of dietary items. The vitamin is the finest example to show the severe difficulty in the strict definition of the term vitamin and in particular, the vitamins that present in the whole-bread. The whole-wheat bread contains presumably, hundreds of compounds related to the vitamin term (including all the polyphenols derivatives) that according to the classical definition are not defined vitamin but they are crucial to reducing morbidity, for high human longevity and even for a shorter period of disability on aging. The classical vitamin term advanced the nutrition theory and practice since the end of the nineteenth century but currently, the forward-thinking approach should be adapted (Challem 1999). At least in some established and defined vitamins, many related compound acting as the termed vitamin, like in the case of vitamin E (Shrader et al. 2012). The classical definition of the vitamins that presumably have not revised >50 y has a major impact on the RDA allotments that also have not revised and even not tested. Thus most of the upper safe limits have no real physiological basis. As a result, some or many of the vitamins deteriorate remarkably the public health status by uncontrolled consumption (Dror et al. 2018). But more importantly, many ingredients like the plethora of anti-oxidants compounds are not regarded as critical and essential nutrients. Such definitions highly impact the whole-bread because the whole bread supplies the foremost content of many critical and essential ingredients for human well-being. Most of the micronutrient ingredient of the wheat, concentrated in the bran fraction. Thus, with the intake of the refined flour, the supply of the micronutrients remarkably decreases while with a moderate intake of the whole-wheat some of the micronutrients supplied affluently. The older individuals with an inadequate intake © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_8

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

of the micronutrients are the population group that most vulnerable to the inadequate intake of particular dietary ingredients. With the inadequate supply of the micronutrients and the anti-oxidants, these people may be at a higher risk for the changes in the brain functioning and the loss of mental and emotional abilities (Dror et al. 2015). Some of the neuropathologic changes associated with the Alzheimers Disease (elevated amyloid burden) and cerebrovascular disease (white matter hyperintensities) observed in clinically normal older adults. Prospective longitudinal studies in cognitively normal older adults revealed that up to 45% of nondemented individuals would histopathologically meet the criteria for Alzheimers Disease. A large portion of the population inadequately supplied with various vitamins, even in the industrialized countries. Notably, aged populations, especially those living in institutionalized settings, are at higher risk for receiving insufficient levels of essential micronutrients. Moreover, several vitamins are necessary for proper brain functioning, and their deficiencies negatively influence cognitive performance. The average intake for the most of the elderly people (>70) adequately supplied (Mohajeri et  al. 2015), but this supply does not cover the lowest percentage for every micronutrient, including elements, with no adequate supply (Kirkpatrick and Tarasuk 2008). With the observations and the opinion that multivitamin supplementation may capable of improving episodic memory performance in older men who are at risk of cognitive impairment, micronutrient supplementation might be crucial (Dror et al. 2002). Taken together with the findings from other studies that have identified cognitive benefits of multivitamins in middle-aged to elderly adults there is growing evidence that daily multivitamin supplementation may useful for the amelioration of cognitive decline (Harris et al. 2012). The classical notion of the vitamin term defines it as an organic ingredient that the organism must acquire from food because his metabolic system cannot synthesize. Later on, a conditional vitamin has defined as an ingredient that the organism cannot synthesize adequately and must acquire an additional amount from food for optimal growth, wellbeing, or longevity. Choline (and other methyl donors), present at high concentrations in the wheat kernel. This ingredient is a typical conditional vitamin because the human body synthesizes choline at a limited scale and presumably in many life styles no additional choline is required. The definitions of the micronutrients have become vague because many of the micronutrients must acquire by our organism adequately but in a narrow window of supplementation (Dror et al. 2018) and because many additional organic micro-ingredients in our diet supporting our wellbeing. The whole-wheat contains many such ingredients. Most of these ingredients have anti-oxidant activities. These ingredients generally disregarded while describing the wheat qualities. However, for the whole-wheat flour, these precious ingredients are very important. The wheat micronutrients comprise some groups: 1 . vitamins, that some of them possess anti-oxidant activity; 2. anti-oxidants such as phenols, polyphenols, tocols, and carotenoids; 3. methyl donors;

8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

139

4. glutathione; 5. policosanols; 6. wheat allergens such as wheat germ agglutinin (WGA). 7. lignans; 8. phytic acid. One of the historical definitions of a vitamin claims that with the vitamin overt signs of deficiency, vitamin supplementation might cure the burden. This classical definition relates to the 13 vitamins for human (Table  8.1). However, could ­temporary inadequate supplementation can ever overcome cell damage that had occurred on insufficient supplementation. Some of the vitamin deficiencies produced easily in animal experimentation but not all of them. No procedure has developed to show overt deficiency symptoms for other micronutrients such as the long list of the polyphenols that poses positive biological activity. Moreover, prevention of the overt symptoms of the deficiency does not assure optimal health status because we have no idea what optimal supply is. The wheat kernel contains many of the vitamins and the other ingredients with alleviative effects. Polyphenols have anti-oxidant properties, and they minimize the negative consequences of oxidative stress. They have anti-inflammatory, anti-allergic, immunomodulatory and anti-mutagenic activities. The polyphenols are powerful anti-oxidants that prevent oxidative stress and reduce the risk of cancer, neurodegenerative and cardiovascular diseases. Their anti-oxidant capacity is comparable to that of the major biological anti-oxidants such as vitamins E and C. In the different plant species, ~8000 polyphenolic compounds with varied and complex chemical structure have identified. They divided into 2 main groups, flavonoids, and non-­ flavonoids, based on the number of the aromatic rings and their binding affinity for different compounds. The flavonoids are the largest group of the polyphenols that further divided into 6 subclasses: anthocyanins, isoflavones, flavanones, flavonols, flavones, and flavanols. 1.1 Flavonoids are composed of 2 benzene rings connected by a 3-carbon bridge. In plants, flavonoids occur together with sugar residues as glycosides or in free form as aglycones. Individual compounds classified according to the different ring substituents created during hydroxylation, methylation, glycosidation, and acylation. 1.2 Non-flavonoids contain at least 1 aromatic ring that linked to 1 or more hydroxyl groups. Non-flavonoids include phenolic acids, lignans, and stilbenes. Phenolic acids further subdivided into 2 groups of cinnamic acid derivatives and benzoic acid derivatives (Lipiński et al. 2017).

1.9 0.32 0.48 0.49 0.42 0.35 0.62 0.59 0.62

CVa

Sourcesb USDAc μg/g 4 0.019 16 3.9 12 43.8 5 0.03 8 9.5 18 0.38 13 3.7 16 1.1 16 7.1 1 0.0027

34

Content Maxd in 170 ge mg 0.019 19 0.81 1.4 7.5 0.78 7.2 86 7.3 0.03 0.12 0.014 3.2 12.2 1.4 0.088 0.9 0.87 0.38 7.5 0.6 0.39 3 0.17 2.4 31 1.04 0.05

Mind

RDAf % of the RDA in 170 g mg/d 0.12 700 1.2 65 16 46 0.030 47 5 35 0.4 22 1.7 20 1.3 13 15 7 90 0.06 0.9 0.015 0.0024 540 6

Human serum ng/ml 0.52 25 5400 0.87 310 7 11 24 11,000 8000 570 28 0.5 0.002 0.1 21. 0.003 1.2 0.03 0.04 0.09 43 32 2.2 0.1 0.002 –

% of total vitamins

Data collected from >210 peers reviewed publications (the references for the kernel composition listed in Appendix 1) a Coefficient of variation for the averages of various sources b Number of sources collected from the published articles (see appendix 1 for the reference list of the sources) c USDA food tables d Minimum or maximum average value for the various sources e Assumming 170 g of the daily intake of the whole-wheat for an adult male f For an adult male g In many nutritional tables the choline does not define as a vitamin. However, choline does not used as a sole methyl donor. In addition to the choline, the wheat kernel contains 2000 μg/g of betaine, trigonelline, and dimethylglycine that metabolized with the choline, make the total contribution of the wheat >60% of the RDA

Average μg/g Menadion (K) 4.8 Thiamin (B1) 4.6 Niacin (B3) 43 Biotin (B7) 0.082 Pantothenic acid (B5) 8.1 Folate (B9) 0.51 Pyridoxine (B6) 3.5 Riboflavin (B2) 1.02 α-tocopherol (E) 10.7 Ascorbic acid (C) 0.27 Retinol (A) 0 Vitamin D 0 Vitamin B12 0 Cholin(B4)g 200

Table 8.1  The wheat kernel vitamins

140 8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

The Vitamins

141

The Vitamins In the developed countries, the populations with a risk for inadequate intakes of vitamins are the elderly, the poor, the homeless, chronic misuse of alcohol, vegetarian/vegan, a patient with multiple gastrointestinal burdens, cardiac, and neuropsychiatric disturbances, and a patient with gastrointestinal surgery (Sechi et al. 2016). Except for the well-known 13 compounds of vitamins with consensual RDAs, choline has declared as a conditional vitamin that sensible nutrition should supply it adequately even no overt symptoms of deficiency have produced in the experimental animals. After choline has quoted with the RDA (550 and 425 mg/d for males and females respectively) in 1998, no additional ingredient has declared as an ­additional vitamin. While choline commonly does not include in almost all commercial preparatory of the ‘multivitamin’, the whole-wheat supplies a considerable amount of choline and other methyl donors (Table 8.6). For optimal health status, other ingredients at adequate supply needed. The wheat kernel contains tens of such compounds that sustain human health. Such ingredients might be defined as conditional vitamins, but so far no precise study with adequate data can support such a definition. Because the wheat products consumed at a considerable part of the total energy intake they supply also a considerable part of all micronutrients requirements for those micronutrients present in the whole-wheat. The vitamin content in the wheat kernels as their part in the RDA sorted in decreasing order with the consumption of 170 g/d of the whole-wheat (Table 10.1). Such an amount provides the consumption of ~30% of the total energy intake while the intake of the specified ingredients supplies some 65 to 20% of the RDA for thiamin, niacin, biotin, pantothenic acid, folic acid, and pyridoxine. The content of the riboflavin and the vitamin E in the wheat kernel has only of the minor effect on the daily intake as it supplied only ~10% of the RDA. The whole-bread contains a long list of micronutrients that do not count in the vitamin list but while consumed at appropriate amounts, improve the proper functioning of the consumer. Wikipedia defines vitamin as an organic molecule which is an essential micronutrient, that is, a substance which an organism needs in small quantities for the proper functioning of its metabolism but cannot synthesize by the host organism, either at all or at sufficient quantities. Therefore, the vitamin must be derived from the diet. Essential minerals resemble the vitamins but they are inorganic compounds while all the vitamins have a carbon skeleton. The term vitamin does not include the 2 other related nutrients namely: essential fatty acids, and essential amino acids. For the human, 14 vitamins have defined (listed with the increasing order of requirement): vitamin B12, vitamin D, vitamin K, biotin, folic acid, vitamin A, thiamin, riboflavin, vitamin B6, vitamin E, pantothenic acid, niacin, vitamin C, and choline. Another animal might have a different vitamin list. Thus, (continued)

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

the putative definition of the vitamin as presented here should revise to include the definition of the supplemented minute of alleviative ingredients consumed with a regular diet. Such a revision is most important for the optimal intake of the whole-bread because it has a remarkable effect as it should be consumed at comparatively high content of the whole-diet energy.

Supplementation of the vitamin C by the wheat is negligible while no vitamins A, D, and B12 present in the wheat. The vitamin K (menadione) in the whole-wheat attracts particular attention. According to the average value (Table 8.1), the vitamin K supplied at a very high level of some 7 times of the RDA but with a very high coefficient of variation. Except for its activity in the cascade of the blood clotting, vitamin K has a major role in bone metabolism and the regulation of the c­ alcification, energy metabolism, and inflammation (Booth 2009). Unstable vitamin K concentration might disturb the mechanism of the blood clotting. Unstable vitamin K concentration and intake might impair the surveillance of the blood clotting. Therefore, continuous monitoring of the bread vitamin K content is required to overcome the fluctuations. The increase of the world wheat marketing and transporting might lead to a higher rate of fluctuation in the vitamin K content that might deteriorate the surveillance of the blood clotting (Dagres et al. 2007).

Other Organic Micro-ingredients The ample supplementation of the whole-list of choline and betaine, tocopherols and other tocotrienols, carotenoids and other yellow pigments, sterols, phenols and polyphenols, resorcinols, flavonoids, lignans, policosanols, glutathione, phytic acid, and protein inhibitors of the wheat, all of them or part of them has presumably a major role in combining the quality of the whole-wheat but still, the avaiable information is limited (Tables 5.2, 5.4, 5.5, 6.1, 6.2, 8.1, 8.2, and 9.3). For many of the items, only 1–7 sources of the concentration determinations have counted. For such a staple food item with the breadth of total energy intake up to 40% of the dietary intake, and probably more, we might expect hundreds of sources for the kernel composition. Such information is most critical for better management of the consumption of the whole-wheat product. The reason for the limited information concern the whole-­wheat kernel presumably occurs because people do not evaluate the vast importance of all of these ingredients and because of the practice of delivering all of these ingredients to feed the animal husbandry. For example, the high ratio of the bound/free compounds of the polyphenols shows the advantage of the wholewheat phenols in comparison to those of fruits and vegetables.

Other Organic Micro-ingredients

143

Table 8.2  The wheat kernel lipophilic anti-oxidants and related ingredient Lipophilic anti-oxidants Tocopherols  Tocopherol, total  Tocols   β-Tocopherol  Tocotrienols   α-Tocotrienol   β-Tocotrienol Carotenoids  Lutein   Not defined   Bread wheat   Durum   Einkorn  Zeaxanthin   α-Carotene   β-Carotene   β-Cryptoxanthin Sterols  Sterols, total  Sterylferulate, total  Campesterylferulate  Sitostanylferulate  Phytosterols, Total  Sitosterol  Sitostanol   δ-7-sitosterol  Campesterol   δ-7-Campesterol  Campestanol  Stigmasterol  Clerosterol  delta7-avenosterol  Stanols  Campestanyl ferulate Phenols  Polyphenols, total  Polyphenols, bound  Polyphenols, free  Phenolic acid, total  Phenolics, free  Phenolics, conjugated

Average

CV

Min1 μg/g

Max1

SD

Sources2

30.5 46.1 5.5 22.1 5.6 22.6 3.7

0.75 0.11 0.67 0.77 0.54 0.44 0.68

2.7 35 1.6 7.7 0.8 3.4 0.26

63 54 15 44.6 11.9 33 10.0

23 5 3.7 17 3 10 2.5

12 10 10 4 12 13 15

3.5 1.5 3.0 6.9 0.63 0.11 0.13 0.11

1.29 0.27 0.04 0.15 1.4 2.5 0.61 1.5

0.34 1.1 2.8 5.7 0.09 0.01 0.005 0.005

18.6 1.9 2.3 7.7 3.33 0.67 0.27 0.3

4.5 0.41 0.12 1.06 0.9 0.28 0.08 0.16

15 3 3 3 12 6 12 3

638 53 7.6 16.9 815 356 84 2.7 112 1.77 52.7 37.1 1.95 27 190 59

745

62 6.3 1.2 1.8 800 180 58

800 100 14 32 860 440 110

260

61

130

36

27.5 13

78 61.2

200

164

204

7 2 2 2 5 5 2 1 5 1 2 2 1 1 3 1

2320 2810 180 880 110 150

1200

400 825

7500 4790

2900 2800

700 13.3 150

440 8.9 115

2300 520 177

450 190 22

800 380

123

26 102

5 2 1 18 11 6 (continued)

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

Table 8.2 (continued)  Phenolics, bound  Ferulic acid total  Ferulic acid bound  Ferulic acid, free  Syringic, bound  Syringic, free  Syringic, conjugated  Sinaptic, total  Sinaptic, bound  Sinaptic, conjugated  Sinaptic, free  Dihydroxybenzoic acid, bound  Dihydroxybenzoic acid, conjugated  Dihydroxybenzoic acid, free  Iso-ferulic acid, bound  Cinnamic acid  p-Cumaric acid, total  p-Cumaric acid, bound  p-Cumaric acid, conjugated  p-Cumaric acid, free  Vanilic, Total  Vanilic, bound  Vanilic, conjugated  Vanilic, free  Diferulic acid  Caffeic, bound  Caffeic, free  4-Hydroxy benzoic,  4-Hydroxy benzoic, bound  4-Hydroxy benzoic, conjugated  4-Hydroxy benzoic, free  Syringaldehyde, free  Chlorogenic acid Genistic acid, bound Protocatechuic acid  Cinnamic acid Tannins Resorcinols  Alkylresorcinols  Heneicosylresorcinol  Alkylresorcinols (c17:0/C21:0) - ratio Flavonoids, total

Average 660 450 385 33 5.4 4.3 8.20 58 13.3 77 2.75 49.7 60.3 0.62 29 27 19.7 15.5 5.8 6.7 19.3 4.3 10.6 3.92 18.6 16.4 0.89 6.7 2.5 4.7 0.25 0.089 4.2 1.7 7.9 27 450

CV 490 490 345 29 4.8 4.1 8.83 60

Min1 390 4.23 120 1.28 2.04 0.005 1.86 31 0.005 69 0.005

Max1 1800 1000 640 140 8.87 8.5 13.3 81 26.6 85 5.50

18.8 14 6.1 1.25 12.4 4.6 11.3 1.71

0.24 2.3 0.71 0.53 0.58 2.8 5 0.31

54 42 10.2 22 94 5 14.8 12

11 5.9 2.8 5.9 0.10

1.27 0.35 4.5 0.69 1.96 0.005

57 1.42 9.7 3.81 6.2 0.80

520 230 0.077 472

490

330

850

0.074 370

0.056 250

0.1 840

SD 450 290 160 38

Sources2 9 18 12 11 6 6 4 6 2 2 2 1 1 1 1 1 11 11 4 7 11 4 4 6 1 5 2 3 4 3 4 1 1 1 1 1 1

140

19 1 6 5 (continued)

The Glutathione

145

Table 8.2 (continued)  Anthocyanins Lignans  Lignan, total  Lignan, matairesinol  Lignan, secoisolariciresinol Policosanol Glutathione Phytic acid Wheat germ agglutinin (lectin) Amylase trypsin Inhibitors3

Average 150

CV 50

Min1 11.3

Max1 490

SD

Sources2 4

5.9 0.063 0.22 10.6 66 10,400 230 4

5 0.063

3.58

11.5

2.8

0.03 0.17 58 2900 19

0.4 21 70 22,000 630

8 1 2 2 3 9 3

70 9000 30

Data collected from >210 peers reviewed publications (the references for the kernel composition listed in Appendix 1). Because the presented data collected from different sources, no adjustment has performed between values. Thus, the value of the total bound polyphenols is greater than the total polyphenols a Minimum and the maximum average value of the various sources. The variation for each source is much higher b Number of resources collected from the collected articles c Schuppan and Zevallos (2015)

The available information for many of the antioxidant compounds present in the wheat kernel is most limited (Table 8.2) as well as for the total antioxidant capacity of most of the food items (Fardet et al. 2008). Wheat is not only a combination of starch, protein, and total dietary fiber but contains also a long list of bioactive compounds that their composition as the crucial components of the typical staple food is most important.

The Glutathione Glutathione (GSH) is the major non-protein thiol in humans and other mammals which is present in millimolar concentrations within cells, but at much lower concentrations in the blood plasma (Giustarini et  al. 2017). The glutathione has not counted as vitamin and presently has even not suggested as a conditional vitamin (Fig. 8.1). Even so, in many physiological conditions, glutathione supplementation probably might improve the physiological status. Because of the limited data available, glutathione cannot count as an essential ingredient and even not as suggested supplemented additive. However, in some studies, the glutathione reckoned as a positive supplemented additive in some physiological conditions (Campolo et  al. 2017; Ly et al. 2015; Richie et al. 2015; Aoi et al. 2015) thus, many distributors are most happy to sell this product (Fig. 8.1).

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

MW 307.3

C10H17N3O6S

Fig. 8.1  The glutathione, shown in two graphical presentations. Glutathione is an iso-tripeptide (GSH, γ-L-glutamyl-L-cysteinyl-L-glycine), a low molecular weight, and a water-soluble thiol compound that is distributed widely in nature. The sulfhydryl group (SH) of the reduced glutathione (GSH) can easily oxidize to the disulfide bond (SS), forming the oxidized glutathione (GSSG) and the protein-bound glutathione under the anaerobic condition or catalyzed by glutathione dehydrogenase. Thus, glutathione exists naturally in GSH, GSSG, and protein-S-SG (PSSG) forms. Furthermore, there are three thiol compounds, i.e. L-cysteine (Cys), L-glutamyl-L-cysteine (Glu-­ Cys) and L-cysteinyl-L-glycine (Cys-Gly), occurring as intermediates in the glutathione synthesis pathway, all of which possess an SH group. Glutathione synthesized from cysteine, perhaps the most important member of the body’s toxic waste disposal team. Like the cysteine, the glutathione contains the crucial thiol (-SH) group that makes it an effective anti-oxidant. The most important of these are the redox reactions, in which the thiol grouping on the cysteine portion of cell membranes protects against peroxidation; and conjugation reactions, in which GSH binds with toxic chemicals to detoxify them. Apart from the role in storage and transport of reduced sulfur glutathione takes part in the detoxification of reactive oxygen species, directly or indirectly acting in the reactive oxygen species detoxification, glutathione participates in methylglyoxal detoxification. It acts as a cofactor in different biochemical reactions, it interacts with hormones, signaling molecules, and its redox state triggers signal transduction. Glutathione modulates cell proliferation, apoptosis, fibrogenesis, growth, development, the cell cycle, gene expression, protein activity, and immune function (Hasanuzzaman et al. 2017). It is a coenzyme in various enzymatic reactions. The GSH is a cofactor for the enzyme GSH peroxidase (HMDB)

The data for the glutathione content in food items is quite limited. Vegetable and fruits contain ~3–15, meat ~5–20 and whole-bread 7  mg/100  g fresh items. The content of refined wheat flour is low. Thus, the steady consumption of whole-wheat has a remarkable contribution to the total glutathione intake.

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147

Glutathione is the most important hydrophilic anti-oxidant that protects cells against the exogenous and the endogenous toxins, including the reactive oxygen and the reactive nitrogen species. Glutathione displays remarkable metabolic and regulatory versatility, which poses the tripeptide at the center stage of a multitude of cellular processes. Glutathione deficiency contributes to oxidative/nitrosative stress, a condition connected with the pathogenesis of many diseases, including cancer, diseases of aging, cystic fibrosis, infection, and neurodegeneration (Aquilano et al. 2014). Glutathione required for many critical cell processes but plays, a particularly important role in the maintenance and regulation of the thiol-redox cell status. The redox state of the GSH/glutathione disulfide couple (GSH/GSSG) can serve as an important indicator of redox environment and changes in this couple appear to correlate with cell proliferation, differentiation, or apoptosis. Maintaining proper glutathione levels, turnover rates and oxidation state are important for some critical cell functions, and disruptions in these processes observed in many human pathologies (Ballatori et al. 2009). Nearly, all the tissues in the body synthesize glutathione. The maintenance of the tissue levels is critical for maintaining health preventing diseases and age-related biological insults. Even partial depletion impairs the immune function and increases the susceptibility to a wide range of xenobiotics and oxidative damage. Low level associated with increased risks of cancer, cardiovascular diseases, arthritis, and diabetes. Oral glutathione increases the plasma and tissue levels and protects against aging-related impairments in the immune function, influenza infections, and cancer. Long-term glutathione supplementation increased body stores (Richie et al. 2015). Numerous glutathione transporters have identified in mammalian cells. GSH, GSSG, and PSSG have recognized as occurring naturally in the wheat flour. Even though the level of the free glutathione in the flour is comparatively lower (66 μg/g) than in the living cells, GSH has considered playing an important role in the redox reactions in the flour and the baking technology, as glutathione content of the flour was found to relate to the rheological properties of the dough (Tea et al. 2005). The glutathione effluxes out of the cell into the extracellular medium, serving as the anti-­ oxidant pool in the immediate environment of the cell, and for the inter-organ transport of the glutathione (and the cysteine). The cells display the capability to import glutathione to replenish the intracellular pools depending on the cellular redox or the nutritional status (Bachhawat et al. 2013). The term “oxidative stress” refers to the imbalance in the production of the reactive oxygen species (ROS) and their neutralization by the anti-oxidant defenses. The brain is particularly vulnerable to oxidative stress. The glutathione is a powerful anti-oxidant that plays a key role in the brain’s capacity for the scavenging ROS and the free radicals. A higher intake of the dietary glutathione positively correlated with higher brain glutathione as assessed by the brain MRI in elderly subjects (Choi et  al. 2015). As glutathione (GSH), the most abundant endogenous anti-oxidant, is a critical regulator of oxidative stress and immune function. Higher body stores assure such critical regulation. A continuous oral supplementation essential to preserve the body stores (Richie et  al. 2015). Human blood concentration of GSH is 1.2  mM and GSSH 1.6  μM (Giustarini et al. 2017).

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

The Tocols In the wheat kernel germ, the α-tocopherol comprises 49% of all tocols (Table 8.3) while 2 forms of tocotrienols comprise 8% of the total tocol content, and no γ and δ forms found (Fig. 8.2). Tocols comprise a chromanol ring with a C16 phytol side chain. Tocols consists of 8 lipid-soluble compounds: α-, β-, γ-, δ-tocopherol, and α-, β-, γ-, δ-tocotrienol. No tocols form synthesize by human. In cereals, the major lipophilic secondary metabolites with anti-oxidant properties include tocols and carotenoids while the α-forms are predominant. Tocopherols are widely distributed in the higher plants whereas tocotrienols occur mainly in some non-photosynthetic tissues such as seeds and endosperm of the monocot grains. The α- and β-tocopherols mainly found in the wheat germ, while tocotrienols are concentrated in the pericarp, testa, aleurone, and the endosperm. Tocotrienols are possibly even more important than vitamin E in their contribution from wheat towards a healthy diet (Labuschagne et  al. 2017; Lachman et al. 2018). The anti-oxidant activity of the wheat results from different groups of hydrophilic and lipophilic anti-oxidant compounds including phenolics, carotenoids, steryl ferulates, and the microelement selenium which is present in dehydrogenases, reductases, glutathione peroxidase, xanthine dehydrogenase, and other selenoenzyme. The tocopherols and the tocotrienols, which grouped as the tocols, are a class of the lipid-soluble anti-oxidants synthesized only by the photosynthetic plants. The tocotrienols are stronger free radical scavengers than the tocopherols activity. In addition to their anti-oxidant properties, the tocol content of the cereals may confer health benefits such as reducing the risks of cancer and the cardiovascular diseases and lowering the LDL cholesterol by inhibiting the cholesterol biosynthesis. The tocotrienols have the potential as the neuroprotective dietary factors. The α-tocopherol possesses the vitamin E activity while the other tocopherols and the tocotrienols do not; however, they all possess anti-oxidant activity and have other health effects. Low concentrations of the tocopherols reported in the wheat bran while the wheat germ contained around 100 μg vitamin E/100 g kernel (Lachman et al. 2013). Table 8.3  The tocols in the wheat germ oil, μg/g, and percentage, (Malekbala et al. 2017) α Tocopherols Tocotrienols

β 1179 (49) 24 (1)

γ 398 (17) 165(7)

δ 493 (21)

118(5)

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149

R2

α-tocopherol MW 430.7

R1 α-tocopherol

α β γ δ

R1

R2

CH3 CH3 H H

CH3 H CH3 H

α-tocotrienol

Fig. 8.2  The tocols that comprise: α-tocopherol has a saturated side chain while α-tocotrienol has a side chain with 3 unsaturated bonds. Each group contains 4 isomers. The scheme depicts the differences between the α-tocopherol (without 3 double bonds in the side chain), on the left, and the α-tocotrienol (that contains 3 double bonds in the side chain), on the right side of the scheme. Each of these 2 molecules might have 4 substitutions on position R1 or position R2. Each of these 8 forms might pose a slightly different activity and role in the total anti-oxidant capacity, The α-tocotrienol found in the blood plasma and all lipoprotein subfractions and traditionally recognized as the most active form of vitamin E in humans and is a powerful biological anti-oxidant. Compared to the tocopherols, the α-tocotrienols are poorly studied. Its presence in the blood plasma at nM (nanomolar) concentrations thought to help to prevent stroke-related neurodegeneration. The α-tocotrienol has found to have vitamin E activity (HMBD). The total tocopherols and the total tocotrienols in the wheat kernel are 30 and 22 μg/g respectively (Table 8.3)

The Tocotrienols Micromolar amounts of the tocotrienol suppress the activity of HMG-CoA reductase, the hepatic enzyme responsible for the synthesis of cholesterol. The unsaturated side chain of the tocotrienol allows for more efficient penetration into the tissues that have saturated fatty layers such as the brain and the liver. Experimental

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

research examining the anti-oxidant, free radical scavenging, effects of the tocopherol and the tocotrienols have found that the tocotrienols appear superior due to their better distribution in the lipid layers of the cell membrane. The basic research on vitamin E has expanded from focusing on α-tocopherol to the investigation of different tocopherols and tocotrienols including anti-inflammatory properties (Ahsan et al. 2014).

The Tocopherols Tocopherols are among the most important lipid-soluble anti-oxidants in food as well as in human and animal tissues (Traber 2004). Tocopherols found in lipid-rich regions of the cell (such as mitochondrial membranes), fat depots, and lipoproteins such as low-density lipoprotein cholesterol (Shahidi and Camargo 2016). The well-­ known function of vitamin E is the chain-breaking anti-oxidant that prevents the cyclic propagation of the lipid peroxidation. Despite its anti-oxidant function, dietary vitamin E requirements in humans are limited only to α-tocopherol because the other forms of the vitamin E poorly recognized by the hepatic α-tocopherol transfer protein, and they are not converted to the α-tocopherol by humans. In attempts to gain a better understanding of the vitamin E health benefits, the molecular regulatory mechanisms of vitamin E have received increased attention. The 4 vitamin forms have different rates of binding affinities to the tocopherol transfer protein, different rates of disappearance and different t1/2 values. The t1/2 of α-tocopherol is ~4 h (Mustacich et al. 2007). The American FDA considers synthetic vitamin E as a half potent of the native α-tocopherol. In the US, an inadequacy of 88% of the American has reported (Ranard and Erdman 2017). The extreme hydrophobicity of the tocopherol poses a major thermodynamic barrier to its distribution and transport through the aqueous milieu of the cytosol and the circulation. As in the case of other small lipids, this barrier appears to have overcome by the evolution of the soluble-binding proteins that mediate the transport of the hydrophobic compounds and regulate their availability (Manor and Morley 2007). Wheat germ oil has important health benefits, such as the lowering blood cholesterol levels, improving physical strength, and possibly reducing the effects of aging, due to its high concentration of nutrients. It is rich in tocopherols, phytosterols, policosanols, thiamine, riboflavin, and niacin. The degradation of lipid quality due to oxidation is of great economic and nutritional importance for the food industry due to the loss of essential fatty acids and fat-soluble vitamins. The lipid peroxidation also produces free radicals, which are associated with health issues (Magariño et al. 2015). As for the other micronutrients, the majority of the tocopherol content concentrated in the bran with a much higher concentration of the tocopherol in the whole-­ wheat flour versus the refined flour (Table 4.3). The average tocopherol content of 0.5  μg/g of refined flour supplies the only small amount of the human needs. However, with the screening of various varieties, a content of 61 μg/g kernel (Whent et  al. 2012), may contribute some basic amount for the daily requirement of the

The Tocols

151

natural vitamin E. Such an amount is important for a considerable part of the population in which many subjects lay at the lower range of the vitamin E intake. The tocol forms and in particular tocopherol form have a different distribution in the edible foods (Table 8.4). Accordingly, the high variation observed between these plasma concentrations. The concentration of the α- form is some fold higher than that of the γ- and the γ- some fold higher than the δ- form (Marchese et al. 2014; Cooney et al. 2008). In the American population the average serum concentration of α-, and γ- are 11,800, and 1800 μg/ml respectively. In the studied population, 51% have routinely supplemented vitamin E with an average serum increase (in comparison to the control) of ~50% of α- tocopherol but with a concomitant decrease of ~30% in the serum γ-tocopherol. At the lower γ-tocopherol concentration the decrease was much higher with a scale of >3 fold (Ford et al. 2006). Because of the high intake of soybean and other vegetable oils rich in γ-tocopherol in the American diet, ~70% of the vitamin E intake from food s in form of γ-tocopherol (Dietrich et al. 2006). The differences in the tocol concentrations in various food items and subjects enabled distinct evaluation of the various tocol concentrations on the decrease in the morbidity. Such differences have evaluated in glioblastoma (Björkblom et al. 2016), in MRI neurology of the deterioration in the brain integrity (Mangialasche et  al. 2013), and possibly prostate cancer (Dietrich et al. 2006). Increasing evidence has accumulated that γ-tocopherol might have an important role in cancer prevention, although particularly human and animal intervention trials are still lacking. In one study, no significant protection for α-tocopherol and selenium but a strong protective association with γ-tocopherol has found. A five-fold reduction in prostate cancer risk as found comparing the highest with the lowest quintile of plasma γ-tocopherol concentration (Wagner et al. 2004). The α-tocopherol is the main anti-oxidant compound in our serum. Besides, the serum contains some other tocol isomers with a lower vitamin E activity (according to the accepted definition) but with special palliative effects on some morbidities. Presently the whole-wheat cover ~7% of the whole-RDA but also, it contains other most important tocols. A steady bread intake of the whole-wheat assures a steady supply of some of the essential tocols including α-tocopherol. The variability in the tocol content (including the α-tocopherol) between various cultivars is quite high. In a small sample of 10 cultivars, the range of 2.0 to 3.4 fold observed for each of the 4 tocol concentrations and in the total tocol concentration (Labuschagne et al. 2014) that are much higher than the ranges of each amino acid at the same cultivar number (Zhang et al. 2016). The high range of the tocol content in various cultivars leaves a wide room for breeding a wheat variety that will cover a remarkable tocol content that normally consumed inadequately or supplied by industrial mixture with a reduced quality. Table 8.4 The α- and the γ-tocopherol in edible oils, μg/g (Grilo et al. 2014) tocopherol α γ α/γ

canola 120 122 0.98

sunflower 431 92 4.7

Corn 173 260 0.67

soybean 71 273 0.26

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

Refined wheat products have only negligible vitamin E and other tocol content, Whole-wheat bread can cover ~7% of the requirement of the vitamin E.  Wheat varieties might breed for a considerable elevated for the tocol content.

The Carotenoids Carotenoids are yellow, orange, and red pigments responsible for the color of most fruits and vegetables. They are C40 isoprenoids with a long conjugated polyene chain that is responsible for their color and biological activities. In cereals, carotenoids occur naturally either in free or esterified forms, mostly with palmitic and linoleic acid (Rodriguez-Amaya 2016). The conventional bread wheat flour contains low levels of total carotenoids (1.9), in comparison to higher values in spelt (4.0), emmer (5.8), durum (6.3), and einkorn wheat (9.6 μg/g), and with some lines >10  μg/g (Paznocht et  al. 2018). The lower concentrations of the carotenoids in conventional bread wheat flour have presumably produced by the continuous struggle to produce the whitest flour for bread baking. Carotenoids are a class of 2 main compounds: (a) Hydrocarbons (carotenes). (b) Oxygenated derivatives of the carotenes (xanthophylls). They consist of 8 isoprenoid units. All carotenoids have formally derived from the acyclic C40H56 structure and having a long central chain of conjugated double bonds. They found throughout the whole-plant kingdom, but their presence often masked by the chlorophyll. They are responsible for the beautiful colors of fruits (pineapple, citrus fruits, tomatoes, paprika, rose hips) and flowers, as well as the colors of many birds, insects, and marine animals (Pfande 1992). Some of the carotenoids, ~50 compounds, decomposed in the intestinal mucosa to produce compounds with retinol activity with the highest efficiency of the β-carotene (Mayne 1996). No retinol for human-derived from plant foods except those decomposed from carotenes. The efficiency of the conversion of the β-carotenes into retinol for the mixed Western diet estimated at the range of 1:16 to 1:9. The conversion ratios have a very high range as found in many studies with the ratios of 1:2–1:77, with notable ratios of, mixed vegetable with a high β-carotene content 1:16, carrot 1:13, orange 1:12, corn 1:6.5, and rice 1:2.3 (Loo-Bouwman et  al. 2014) (Figs.  8.3 and 8.4). Plasma levels of the carotenoids are determined by their intakes from the diet, but about 95% of the plasma carotenoids represented by only 6 carotenoids (Table 8.5). The last 3 carotenoids termed “the yellow pigments” with a particular role in the ocular functions (see latter on the yellow pigments). Nutritional and health effects of carotenoids are due to their multidirectional biological effects in humans, includ-

The Carotenoids

MW 537

153

C40H56

Fig. 8.3 The β-carotene (content in wheat kernel 0.1 μg/g), shown in two graphical presentations. The β-carotene is a carotenoid that is a precursor of retinol. Carotene is an orange photosynthetic pigment. It is responsible for the orange color of the carrot and many other fruits and vegetables. It contributes to photosynthesis by transmitting the light energy it absorbs to chlorophyll. Chemically, carotene is a terpene. It is the dimer of retinol and comes in 2 main primary forms: α- and β-carotene, and also γ-, δ- and ε-carotenes. Carotene can be stored in the liver and converted into retinol as needed. The β-carotene is an anti-oxidant and such can be useful for curbing the excess of damaging free radicals in the body. However, the usefulness of β-carotene as a dietary supplement (taken as a pill) is still subject to debate. The β-carotene is fat-soluble, so a small amount of fat needed to absorb it into the body

Fig. 8.4 The α-carotene (in wheat kernel 0.3 μg/g). The α-carotene is one of the primary isomers of the carotene. This compound belongs to the class of the organic compounds known as carotenes. These are a type of the unsaturated hydrocarbons containing 8 consecutive isoprene units. They are characterized by the presence of the 2 end-groups (mostly cyclohexene rings, but also cyclopentene rings or acyclic groups) linked by a long branched alkyl chain. The carotenes belonging form a subgroup of the carotenoids family (HMBD)

ing anti-oxidant, anti-inflammatory, and immunomodulatory properties (Zielińska et al. 2017; Eggersdorfer and Wyss 2018) During the development of modern bread-­ wheat cultivars, selection has been towards a white creamy our and relatively low levels of lutein (Carver 2009). The carotenoids have a particular role in the issue of the whole-wheat bread. Unlike other anti-oxidants, a major part of the carotenoids and related compounds existed in the endosperm. The endosperm carotenoids that termed the “yellow ­compounds” had “spoiled” by their “unpleasant color” the purity of the white flour.

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

Table 8.5  The carotene concentrations in the plasma of the European populations (Eggersdorfer and Wyss 2018) β-Carotene α-Carotene Lycopene β-Cryptoxanthin Lutein Zeaxanthin Meso-zeaxanthine

Range, μM 0.21–0.68 0.06–0.32 0.43–1.32 0.11–0.52 0.26–0.70 0.05–0.13

Median, ng/ml 242 102 467 177 273 54

MW 537 537 537 553 569 596 569

When more and more bread baked from the “pure” white flour, the market demanded the whiter flour. Within a comparatively short period, the wheat breeders have responded to the challenge and bread wheat varieties with a “clean and white” flour. Later on, they restored the durum wheat that used for the pasta market, some of the yellow pigments. Eventually the wheat breeder “cleaned out” the yellow pigments with a considerable decrease in the carotenoids content. Since the genes of the carotenoids synthesis preserved in the ancient varieties, restoration of the ­carotenoids might easily restore. The cereals, although having a low carotenoid content when compared with the majority of the fruits and the vegetables, may have an important impact on the nutritional status of the consumers. The daily consumption of the cereals, and the products derived from them, by a large part of the population, makes cereals an attractable contributor of the carotenoids supply that should take into consideration in the biofortification strategies (Mellado-Ortega and Hornero-­ Méndez 2015). While in the bread wheat, the “yellow-pigments” have “successfully” cleaned-up they have preserved in the durum wheat produced for the pasta products. The so-­ called “yellow pigment” content of the durum wheat has used for a long time as an indicator of the color quality of the durum wheat and the pasta products. For decades, the chemical nature of these pigments has assigned to the carotenoids, mainly to the xanthophyll lutein and their fatty acid esters. Unlike the dietary fiber, the polyphenols, and other micronutrients, the concentrations of the yellow pigment quite similar on the various streams of the flour refining (Hentschel et al. 2002). The wheat total carotenoids content is 3.7  μg/g whole-wheat; the lutein comprises the main content with 3.5 μg/g but with a wide range observed between the bread wheat with 1.5 μg/g and the einkorn varieties with 6.9 μg/g (Table 8.2). After the bakery market has constructed the major “nutritional crime” of the refined flour bread, the bakery market has constructed a minor “nutritional crime” by excluding the yellow pigments from our bread. For the elderly population with a high rate of age-related macular degeneration (AMD), other retinal disturbances, and cataract episodes, such a “clean and white” bread has a major disadvantage. While the carotenoids are yellow, orange, or red plant pigments, in the green leaves, the carotenoids are usually invisible because of the masking by the presence of the chlorophylls.

The Carotenoids

155

The carotenoids are located in oil droplets, crystalloids and membrane structures within specialized vegetable organelles, the so-called plastids, being the most common the chloroplasts (in green tissues) and the chromoplasts (yellow, orange and red tissues), and found in all parts of the plant. The anti-oxidant function of the carotenoids is that they are capable of preventing the damage caused by the formation of chlorophyll triplets and singlet oxygen. When the carotenoids ingested, they exert important biological activities; anti-oxidant, inhibition of carcinogenesis, enhancement of the immune response and cell defense against the reactive oxygen species (ROS) and the free radicals, and the reduction in the risk of the developing the cardiovascular and other degenerative diseases (Mellado-Ortega and Hornero-­ Méndez 2015). The protective mechanism of the carotenoids based on their ability to scavenge the excitation energy of the chlorophyll triplets, thus dissipating it as heat, or to quench singlet oxygen molecules. Besides, the carotenoids perform the function of the photo protectors. The carotenoids can locate in various parts of the chloroplasts and, accordingly, perform different functions. The carotenoids also found in seeds of all plants. The hydrocarbons carotenes (α-, β-, and γ-carotenes) and the xanthophylls, the oxygen-containing pigments (the xanthophylls) classified into the hydroxylated derivatives, C40H54(OH)2, such as lutein and zeaxanthin, and the epoxy derivatives such as the violaxanthin and the neoxanthin (C40H56O4) that contain hydroxyl and epoxy groups. The most common plant carotenoids are the β-carotene and the xanthophylls lutein, the violaxanthin, and the neoxanthin. Under the high-intensity light, the chloroplasts accumulate antheraxanthin and zeaxanthin. The majority of carotenoids comprise a C40-hydrocarbon skeleton having the conjugated double bonds (Smolikova and Medvedev 2015; Julkunen-Tiitto et al. 2015). The capacity of the plant cellular anti-oxidative and the photo-protective defense toward the harmful reactive oxygen species, produced by the natural and the man-­ made stress situations, determined by the pool size of the anti-oxidants and the protective pigments (Fratianni et al. 2013). After consumption, zeaxanthin released from the food matrix by the digestive enzymes and then solubilized into the lipid emulsions and transported from the stomach to the duodenum. In the duodenum, the carotenoids solubilized into mixed micelles along with the dietary triacylglycerols, phospholipids, cholesterol esters, and the bile acids. The fats and the oils have known to enhance not the bio-­ accessibility as well as the bioavailability of the carotenoids by the dispersing them through the digestive tract. The dietary fibers, which bind the bile acids, considered to decrease the bio-accessibility (Manikandan et al. 2016). The yellow pigment concentration of the durum wheat complexly inherited, and the genetic control is complex. The heritab.ility is quite high (a range of 3.5–8.7, average 6 μg/g kernel) (Clarke et al. 2011). The following ranges (and averages) for the specific compounds have observed, lutein 0.2–1.5 (1), zeaxanthin 0.1–0.28 (0.17) and β-cryptoxanthin 0.01–0.14 (0.06) μg/g, respectively (Zhang et al. 2005; Schulthess and Schwember 2014; Graham and Rosser 2000; Clarke et al. 2011; Olmedilla et  al. 2001; Julkunen-Tiitto et  al. 2015; Manikandan et  al. 2016; Bernstein et al. 2016).

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

The Xanthophylls These carotenoids include lutein, its structural isomer zeaxanthin (Fig.  8.7) and meso-zeaxanthin (Fig.  8.8). Animals do not synthesize carotenoids. In primates, dietary lutein and its isomers are selectively concentrated in the eye and brain over other carotenoids in the blood, comprising 80% to 90% of carotenoids in human eyes and the majority of carotenoids in the brain. They are the exclusive carotenoids in the neural retina and the lens. The highest concentration of the lutein and the zeaxanthin in the eye is in the macula of the retina (Mares 2016). The lutein and the zeaxanthin that accumulate in the lens and the retina protect the ocular tissues against the singlet oxygen and the lipid peroxide damage. Beginning with the middle age, the anti-oxidant protection depleted and this leads to the formation of age-­ related cataracts and macular degeneration. Increasing the intake of the fruits and the vegetables, high in lutein and zeaxanthin, has found to retard age-related cataracts and the macular degeneration. Supplementation with lutein and zeaxanthin is very effective at restoring these important ocular anti-oxidants. The lutein and the zeaxanthin have a 40-carbon basal structure, absorb light in the visible range; the lutein and the zeaxanthin absorb blue visible light (400–500  nm) (Roberts and Dennison 2015) (Fig. 8.5).

The Lutein In plants, carotenoids contribute to the photosynthetic process by acting as light collectors and photo-protectors. The wheat as the most important crops contains low carotenoid contents compared to most of the vegetables and fruits. The lutein is an endogenous plant pigment that is located in the plastid membranes of the plants

Fig. 8.5 The β-cryptoxanthin (content in wheat kernel 0.3 μg/g). The β-cryptoxanthin is a natural carotenoid pigment. In a pure form, the cryptoxanthin is a red crystalline solid with a metallic luster. In the human body, the cryptoxanthin converted to retinol and therefore considered a provitamin A. As with the other carotenoids, the cryptoxanthin is an anti-oxidant and may help prevent the free radical damage to the cells. Structurally, the cryptoxanthin closely related to β-carotene, with only the addition of a hydroxyl group. It is a member of the xanthophylls. The β-cryptoxanthin is a major source of the retinol, often second only to β–carotene (HMBD).

The Lutein

157

and is an important micronutrient for humans. The widespread and daily-based ­consumption of the cereals and the derived products makes these staple foods an important source of these anti-oxidants in the diet. The major carotenoid present in wheat is lutein. Durum wheat characterized for presenting a yellowish color due to the carotenoids. The lutein represents 80–90% of the total carotenoid content and contributes to the pale creamy to the yellow color of the wheat-based end products. In the harvest-ripe wheat grain, the lutein is present primarily as free lutein. It is prone to oxidative degradation during storage and oxidation involving lipoxygenase during processing. During post-harvest storage, the lutein converted to fatty acid esters, which appear to be more stable than the free lutein by substitution of the fatty acids at one or both hydroxyl groups at the ends of the lutein molecule (MelladoOrtega and Hornero-Méndez 2017; Ahmad et al. 2015). The lutein and the zeaxanthin have a protective role in the prevention of chronic diseases. Although to date, a wide range of the carotenoids has identified in human ocular tissues, the major carotenoids in the human macula are the lutein and the zeaxanthin. The concentration of the macular carotenoids can manipulate by the dietary intake of the lutein and the zeaxanthin and that have an important role in the prevention of the AMD (age-related macular degeneration). The concentration of the lutein in the green vegetables is much higher than that of the zeaxanthin (Fig. 8.6).

MW 569

C40H56O2

Fig. 8.6  The lutein (in wheat kernel 4  μg/g. Lutein is a common carotenoid xanthophyll. Carotenoids are among the most common pigments and are natural lipid-soluble anti-oxidants. Lutein is one of the 2 carotenoids (the other is zeaxanthin) that accumulate in the eye lens and the macular region of the retina with concentrations in the macula greater than those in plasma and other tissues. Lutein and zeaxanthin have identical chemical formulas and are isomers, but not stereoisomers. The main difference between them is in the location of a double bond in one of the end rings. This difference gives lutein 3 chiral centers whereas zeaxanthin has 2. A relationship between macular pigment optical density, a marker of lutein and zeaxanthin concentration in the macula, and lens optical density, an antecedent of cataractous changes, has suggested. The xanthophylls protecting the eye from ultraviolet phototoxicity via quenching reactive oxygen species. Generous intakes of lutein and zeaxanthin, have reduced the risk for cataract and age-related macular degeneration (HMDB)

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

The abundance of the lutein over the zeaxanthin in nature has attributed to the dominant role of the lutein in the photosynthesis (Humphries and Khachik 2003). The lutein has reported protecting against the detrimental effects of the long-term computer display light exposure also in the healthy, young adult subjects (Johnson 2014). The zeaxanthin is structurally closely similar to lutein. The intake of both carotenoids in the human diet regarded as healthy, with these components reflecting an adequate intake of fruit and vegetables. The zeaxanthin has an important role in the xanthophyll cycle (Edwards 2016) (Fig. 8.7). The wheat varieties with the diploid genome, in particular, the einkorn (Triticum monococcum) wheat, contain these carotenoids with the highest levels, in the order of ~2–4 times higher than the other wheat varieties. However, an inverse situation occurred with the bread wheat destined to the flour production, which presents lower levels of the carotenoids due to the pressure exerted by the industries motivated by the consumer preference for a whiter flour for the further preparation of flour-containing products according to the market demand (Mellado-Ortega and Hornero-Méndez 2015). The meso-zeaxanthin does not generally present in the diet. Its presence in the macula is due to conversion from lutein. In the macula, the lutein, the zeaxanthin,

MW 569

Fig. 8.7  The zeaxanthin (in wheat kernel 0.6) μg/g. The zeaxanthin is a carotenoid xanthophyll and is one of the most common carotenoids found in nature. The zeaxanthin pigment gives the corn, saffron, and many other plants their characteristic color. The zeaxanthin breaks down to form the picrocrocin and the safranal, which are responsible for the taste and aroma of the saffron. The zeaxanthin is one of the 2 carotenoids (the other is lutein) that accumulate in the eye lens and the macular region of the retina with the higher concentrations in the macula than those found in plasma and other tissues of the body (HMBD).

Fig. 8.8  The meso-zeaxanthin (present only in animals)

The Methyl Donors

159

and the meso-zeaxanthin referred to as macular pigment and believed to prevent damage that leads to age-related macular degeneration, Lutein may also play a role in the early visual development (Johnson (2014) (Fig. 8.8).

The Methyl Donors The whole-flour contains a much higher concentration of the methyl donors than the refined flour wheat. Within the limited sample number that we gathered, we noticed a six-fold higher choline concentration for the upper level leaving a wide room to increase the choline content under the market demand. Choline dietary intake varies such that many people do not achieve adequate intakes. Diet intake of choline can modulate methylation because, via betaine homocysteine methyltransferase, this nutrient (and its metabolite, betaine) regulate the concentrations of S-adenosylhomocysteine (Zeisel 2017). The choline is the main methyl donor synthesized by the human tissues but in many cases not at an adequate amount. Therefore, a substantial choline supply or a supply of another methyl donor must be derived from food. Whole-wheat has a high content of choline and other methyl donors such as betaine, trigonelline, and trimethylglycine. The total methyl donors in the whole-wheat may cover >60% of the choline requirement as specified by the DRI (Table 8.6). Choline is an essential nutrient with functional relevance in a wide array of biological pathways including epigenetic modulation of gene expression. The US FDA set the RDI for choline in 2016 as 550 mg/d for an adult man. The choline is active in many reactions that required methyl donation which one known is the epigenetic activity. Our genetic code is the same in almost every cell, yet not all tissues express every gene to the same extent (Zeisel 2017). Choline is a precursor of membrane phospholipids, the neurotransmitter acetylcholine, and via betaine, the methyl group donor of S-adenosylmethionine. High choline intake, in an animal model, during gestation and early postnatal development improves the cognitive function in adulthood, prevents age-related memory decline, and protects the brain from the neuropathological changes associated with Alzheimer’s disease, and neurological damage associated with epilepsy, fetal alcohol syndrome, and inherited conditions such as Down and Rett syndromes. Dietary choline intake in the adult may also influence cognitive function (Blusztajn et al. 2017). Betaine, choline, dimethylglycine, and trigonelline are compound with the availability to donor methyl group to another compound. The methyl-donors compound present in the wheat kernel generally considered as an interchangeable compound. Choline and betaine are methyl donors, present at high concentrations in the whole-wheat products. The normal intake of the methyl donors in Western societies does not meet the optimal requirement (Blusztajn and Mellott 2013) while the intake of the methyl donors has a considerable impact on human health. For a long time, methyl-donors have disregarded in human nutrition as noteworthy ingredients because no overt clinical symptoms have observed when methyl donors consumed

Wheat Whole grain mg/100 g 130 48

240 20 0.36 50

Whole flour 1, 2 72 24

Refined flour, 1 1293 88

Bran, 1 1163 168

Germ, 1 1550 209

Aleurone, 2

18

4

8

46

Rye Rice Oat Buckwheat

Whole-kernel

1 Likes et al. (2007); 2 Corol et al. (2012); 3 not a methyl donor but, its metabolism related to choline metabolism

Betaine Choline (B4) Trigonelline Dimethylglycine3

Methyl donors

Table 8.6  The content of the methyl donors in the wheat kernel and some other cereals

2

μg/mL 3.6 1

Human serum

425/550

RDA Female/ Male mg/d

160 8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

The Methyl Donors

161

at a low or a high intake. Methyl donors are compounds that their adequacy might prove only on a delicate scale. Even so, these minor effects might change considerably the trends of morbidity and mortality. Betaine and choline are present in the whole-wheat at high amounts (Table 8.6) and thus, they are weighty methyl donors in our menu. The high content of choline and particularly the betaine in the whole-­ wheat bread might be one of the main factors contributing to the advantage of the whole–wheat upon refined flour. Some other ingredients such as dietary fiber, total anti-oxidant capacity, and other micronutrients comprising also the advantage of the whole-bread but no methodology are available to define the partial contribution of each one of this component.

The Choline Choline, designated as vitamin B4, is a ubiquitous water-soluble nutrient. Practically choline is an essential nutrient and a substantial amount should derive from food. The remethylating of homocysteine into methionine and providing methyl groups for DNA and other methylation reactions are dependent on ample availability of the methyl donors (Ross et al. 2014). The mammals synthesize choline to some extent and mammals fed a choline-­ deficient diet develop liver dysfunction; Humans ingesting a choline-deficient diet for 3 wks had diminished plasma choline and phosphatidylcholine concentrations as

MW 104.2

C5H14NO

Fig. 8.9  The choline. The choline is a basic constituent of lecithin that found in many plants and animal organs. It is a precursor of acetylcholine, a methyl donor in various metabolic processes, and lipid metabolism. The choline considered an essential vitamin. While humans can synthesize small amounts (by converting phosphatidylethanolamine to phosphatidylcholine), it must consume in the diet to maintain health. The required levels are between 425 mg/d (female) and 550 mg/d (male). Milk, eggs, liver, and peanuts are especially rich in choline. Most choline found in phospholipids, namely phosphatidylcholine or lecithin. Choline can be oxidized to form betaine, which is a methyl source for many reactions (such as the conversion of homocysteine to methionine). Lack of sufficient amounts of choline in the diet can lead to a fatty liver condition and general liver damage. This arises from the lack of VLDL, which is necessary to transport fats away from the liver. Choline deficiency also leads to elevated serum levels of alanine aminotransferase and is associated with an increased incidence of liver cancer (HMBD)

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8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

well as diminished phosphatidylcholine concentrations in the erythrocyte membrane. The demand for choline as a methyl donor is probably the major factor that determines how rapidly a diet deficient in choline will induce pathology. In many mammals, chronic ingestion of a diet deficient in choline has the major consequence that includes hepatic, renal, pancreatic, memory, and growth disorders. Observational studies suggest that choline may be beneficial for neurological health, particularly cognition and insulin sensitivity. Supplementation during pregnancy may have a beneficial effect on the neurological health of the child, particularly cognition (Leermakers et al. 2015). Dietary intake of betaine and choline has recently been inversely associated with inflammatory markers related to atherosclerosis. While adequate choline has profound effects on health status, it has a much critical role in human fetus. Maternal nutrition, and in specifically the availability of methyl donors such as choline, may determine the number of stem cells available postnatal neurogenesis as well as the structure of the hippocampus. Choline and its related compounds have several biologic functions by serving as components of the structural lipoproteins, blood, and tissue lipids and as a precursor available for the neurotransmitter acetylcholine (Zeisel et al. 1991; Konstanti-nova et al. 2008; Cheatham 2014; Gao et al. 2016; Yonemori et al. 2013). Choline dietary intake highly varied between societies and individuals and many people do not acquire adequate intakes. The US National Health and Nutrition Examination Survey (NHANES 2009–2012) reports that only 11% of adult Americans achieve the Adequate Intake level of choline, with the mean intake being 300 mg/d (Yonemori et al. 2013) (Fig. 8.9). Thus, according to the consensual approach, choline defined as a vitamin even typical dietary intake contains a considerable amount of choline and therefore choline deficiency in healthy subjects rarely reported. In many conditions, adequate supplementation of choline improves health status. There is significant variation in the dietary requirements of choline that can explain by common genetic polymorphisms. The adequate supply of choline and the other methyl donors by the whole-­ wheat might have overt effects on the population health indicators (Zeisel 2000; Wallace and Fulgoni 2016). Almost all of the ‘multivitamins’ formulations do not contain choline because of the high quantity needed, a comparatively high price of synthetic choline, because no regulations have imposed in the ‘multivitamins’ market and because the industry and the advertising system for the ‘multivitamin’ purchasing, presumably consider that choline is not an attractive item for the increase in the marketing. The withdrawal of the choline and the betaine from the majority of the baked bread and the wheat products (by refining) has aggravated the choline status in Western populations. Choline and betaine, both present at a considerable concentration in the whole-wheat, are quaternary amines with a close metabolic link. Based on estimates of the dietary intake data, cereal foods provide ~60–67% of betaine in Western diets, and 20–40% of betaine in South-East Asian diets. In Western ­societies, ~73% of the total betaine intake derived from cereals (Ross et al. 2014). Choline and betaine do not present evenly in the refined flour and bran while choline concentration in bran is about three-fold and the betaine concentration in bran is ~40 fold higher than that of refined flour (Graham et al. 2009).

The Methyl Donors

163

The Betaine The betaine and the choline content of whole-wheat flour are higher by four fold than that of white flour (Likes et al. 2007). Apparently, as their main function of the methyl donors, both compounds might be interchangeable. While choline defined as an essential ingredient, betaine does not. Betaine has a particular role in human metabolism even betaine might derive metabolic from choline. Serum betaine was inversely associated with breast cancer risk while serum choline has not shown such an effect (Du et al. 2017). Betaine content of the whole-wheat higher by some fold than that of choline (Table 8.6) and might exert the major alleviative effect of the whole-wheat as the methyl donor. Betaine has critical functions as an osmolyte and methyl donor in the human body but does not consider as an essential nutrient because it can irreversibly synthesize from free choline by the choline dehydrogenase activity. In the whole-bread, betaine appears to comprise a remarkable ingredient. Even only 8% of the RDA (with the consumption of 100 g flour) of choline derived from the wheat products (Table 8.6), such a supply cover a higher portion of the daily intake because in many subjects the total choline intake is much lower than the RDA. The betaine content in the whole-wheat is much higher by more than ten fold but no estimation for its requirement has published. Choline might convert to betaine but not vice versa. The quantitative effect of betaine might overweigh choline activity. Much more information has published on the nutritional effect of choline than the effect of choline but some specific effects of betaine are noteworthy. The betaine intake and serum concentration promotes adiposity reductions, has positive effects of betaine on sports performance and reduces the relative risk for breast cancer (Du et al. 2017; Ying et al. 2013). The betaine content of the whole-­ wheat is >4 times higher than the choline content (Table 8.6) and because of its high content might be the most significant ingredient. Betaine is essential as a tissue osmolyte and as a source of methyl groups, and the supply of the betaine affects lipid metabolism. This supply may be inadequate in some patients with diabetes mellitus or with metabolic syndrome, and these patients typically have elevated plasma homocysteine and dyslipidemia. Therefore, a low intake of betaine may contribute to the health problems of this increasing section of the population. This subgroup could benefit from a modest level of betaine supplementation, and long-term prospective studies needed to evaluate the probable benefits. Pregnancy increases the demand for betaine, in the period immediately before and after conception, later in pregnancy and in infancy. (Lever and Slow 2010). The whole-grain contain high betaine concentration that may explain some the whole-grain advantage. In an animal experimental study, in rats fed whole-grain flour, the livers had more GSH and betaine than those fed refined wheat flour. The relatively high concentration of the betaine in the liver produced by the high betaine content of the whole-grain flour. The wheat bran is a major dietary source of betaine and the concentration in the white flour is, in comparison, very low. As the bran accounts for 15–17% of the whole-grain wheat, there would be ~140 times more

164

8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

betaine in the whole-grain flour than in the refined wheat flour. A higher betaine concentration in the plasma and the urine previously observed in pigs fed a wholegrain rye diet. The betaine participates in the conversion of the homocysteine to the methionine. The methionine added to the freshly isolated hepatocytes increases the intracellular GSH (Fardet et al. 2018) (Fig. 8.10).

The Dimethylglycine N,N-dimethylglycine (DMG), is a methylated derivative of the amino acid glycine with the chemical formula of (CH3)2NCH2COOH, has used for various human and animal applications. The dimethylglycine first reported in 1943, occurring naturally as an intermediate metabolite in the plant and the animal cells. The choline-to-­

MW

143

C7H13NO2

Fig. 8.10  The betaine (Filipcev et al. 2018). The betaine, (N, N, N-trimethylglycine) was named after its discovery in sugar beet (Beta vulgaris) in the 19th century. It is a small N-tri-methylated amino acid, existing in zwitterionic form at neutral pH. It often called glycine betaine to distinguish it from other betaines that are widely distributed in the microorganisms, plants, and animals. Many naturally occurring betaines serve as organic osmolytes. These substances synthesized protect against osmotic stress, drought, high salinity, and high temperature. Intracellular accumulation of betaines permits water retention in cells, thus protecting from the effects of dehydration. Betaine functions as a methyl donor in that it carries and donates methyl functional groups to facilitate necessary chemical processes. In particular, it methylates homocysteine to methionine, also producing N, N-dimethylglycine. The donation of the methyl groups is important for proper liver function, cellular replication, and detoxification reactions. Betaine also plays a role in the manufacture of carnitine and serves to protect the kidneys from damage. Betaine derived from the diet or by the oxidation of choline. Betaine insufficiency is associated with metabolic syndrome, lipid disorders, and diabetes, and may have a role in vascular and other diseases. Betaine is important in development, from the pre-implantation embryo to infancy. Betaine is also widely regarded as an anti-oxidant. Betaine has shown to have an inhibitory effect on NO release in the activated microglial cells and may be an effective therapeutic component to control neurological disorders. As a drug, betaine hydrochloride was used as a source of hydrochloric acid in the treatment of hypochlorhydria. Betaine has also used in the treatment of liver disorders, for hyperkalemia, for homocystinuria, and gastrointestinal disturbances (HMBD). In the USA, the average dietary betaine intake is about 100–300 mg/day and rarely exceeds 400–500 mg. Human blood plasma typically contains 25–66 μM (Hefni et al. 2018; Bjørndal et al. 2018)

The Methyl Donors

165

MW 103 C4H9NO2 Fig. 8.11  The dimethylglycine, shown in two graphical presentations. Dimethylglycine is an amino acid derivative found in the cells of all plants and animals. The human body produces dimethylglycine when metabolizing choline into glycine. The dimethylglycine that does not metabolize in the liver, transported by the circulatory system to other tissues. Dimethylglycine is also a byproduct of homocysteine metabolism. Homocysteine and betaine converted to methionine and N, N-dimethylglycine by betaine-homocysteine methyltransferase. Dimethylglycine in the urine is a biomarker for the consumption of legumes (HMBD)

glycine pathway starts with choline oxidized into betaine. Dimethylglycine formed within the mitochondria from betaine (Fig. 8.11). Dimethylglycine claimed to enhance oxygen utilization and diminish muscle acidification, and for this reason, dimethylglycine currently used as an enhancer of athletic performance in athletes as well as in animal racing (Kalmar et al. 2012). Many amino acids are important not only for protein synthesis but also as metabolites for critical metabolic reactions. Some of these ‘non-protein’ roles of amino acids can utilize a significant proportion of the total amino acid pool. For indispensable amino acids, these alternative metabolic pathways must carefully consider when establishing the dietary requirement of that amino acid. The upregulation of the downregulation of these pathways can tax or spare the amino acid requirement, respectively, depending on the pathway in question and the availability of alternate metabolites. For example, methionine is an essential amino acid that is necessary for the synthesis of cysteine and taurine as well as for the methyl-groups supply. These methyl groups needed, inter alia, for the synthesis of creatine, phosphatidylcholine, and carnitine and for regulating gene expression via cytosine and histone methylation. Methyl groups for the remethylation to methionine can provide by methyl donors such as choline and betaine and by methyl-neogenesis. In adults, the major dietary sources of labile methyl groups are methionine (~10 mmol methyl/d), choline (~30 mmol methyl/d), betaine (26–75 mmol/d), and the methylneogenesis (5–10  mmol/d). Because of folate, choline and methionine are all essential nutrients, the dietary availability of folate, choline, and betaine can influence the amount of methionine needed. Moreover, the dietary supply of methylated products such as creatine, carnitine, and phosphatidylcholine could reduce the need for methyl groups and further spare methionine requirement (Bertolo and McBreairty 2013).

166

8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

The Trigonelline Whole-wheat contains 3.6 μg/g trigonelline (Table 8.6), with some potential as a methyl donor. Some evidence has shown trigonelline possess hypoglycemic, neuroprotective, anti-invasive, estrogenic, anticancer, and antibacterial activities and it has anti-carcinogenic effects (Ashihara et  al. 2015). In coffee beans, trigonelline content is much higher than in wheat at a concentration similar to that of caffeine (Fig. 8.12).

MW 137

C7H7NO2

Fig. 8.12  Trigonelline. Trigonelline, an alkaloid, is a product of the metabolism of niacin that excreted in the urine. It found in coffee, where it may help to prevent dental caries by preventing the bacteria Streptococcus mutants from adhering to teeth. Trigonelline occurs in many other plants, including fenugreek seeds, garden peas, hemp seed, oats, and potatoes (HMBD)

The choline has recognized by the American IOM (Institute of Health) as a compound with Recommended Dietary Allowance (RDA) and thus choline became the 14th vitamin compound for humans. Because overt signed of inadequate intake for choline have not observed, and because that some inadequate amount of choline is synthesized in our tissues, the public and the health authorities ignore the necessity to preserve adequate intake of this compound as well as other methyl donors. The choline supplementation for the majority of the individuals is far below the RDA. The intake of whole-wheat for the refined flour wheat with its higher content of methyl donor compounds opens an opportunity to close the gap of choline inadequacy in the majority of the population. Presently, when the majority of the wheat consumed as refined products, the breeding of a cultivar with a higher content of such compounds is almost useless because that most of the choline diverted outside the human menu for animal feeding with the bran. Only marginal amounts are left in the kernel endosperm and used for human needs. Most of the variation in the composition of wheat samples could ascribe to the genotype rather than the environment, allowing a comparison of genotype quality. The concentrations of betaine, choline, and trigonelline in the bread wheat typically followed a

References

167

normal distribution with significant variation in concentrations leave a reasonable margin to breed varieties with the high content of the methyl donors (Corol et al. 2012). The choline DRI for infants and toddlers is higher by more than two fold (as calculated per kg body weight) than that of adult DRI (up to 18.1 versus 7.7 mg/kg per d, respectively). Therefore, the intake of whole-­ wheat products is much more important in these age groups.

References Ahmad FT, Mather DE, Law HY, Li M, Yousif SAJ, Chalmers KJ, Asenstorfer RE, Mares DJ (2015) Genetic control of lutein esterification in wheat (Triticum aestivum L.) grain. J Cereal Sci 64:109–115. https://doi.org/10.1016/j.jcs.2015.05.007 Ahsan H, Ahad A, Iqbal J, Siddiqui WA (2014) Pharmacological potential of tocotrienols: a review. Nutr Metab 11:52. https://doi.org/10.1186/1743-7075-11-52 Aoi W, Ogaya Y, Takami M, Konishi T, Sauchi Y, Park YY, Wada S, Sato K, Higashi A (2015) Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism. J Int Soc Sports Nutr 12:7. https://doi.org/10.1186/ s12970-015-0067-x Aquilano K, Baldelli S, Ciriolo MR (2014) Glutathione: new roles in redox signaling for an old antioxidant. Front Pharmacol 5:196. https://doi.org/10.3389/fphar.2014.00196 Ashihara H, Ludwig IA, Katahira R, Yokota T, Fujimura T, Crozier A (2015) Trigonelline and related nicotinic acid metabolites: occurrence, biosynthesis, taxonomic considerations, and their roles in planta and in human health. Phytochem Rev 14:765–798. https://doi.org/10.1007/ s11101-014-9375-z Bachhawat AK, Thakur A, Kaur J, Zulkifli M (2013) Glutathione transporters. Biochim Biophys Acta – Gen Subj 1830:3154–3164. https://doi.org/10.1016/j.bbagen.2012.11.018 Ballatori N, Krance SM, Notenboom S, Shi S, Tieu K, Hammond CL (2009) Glutathione dysregulation and the etiology and progression of human diseases. Biol Chem 390:191–214. https:// doi.org/10.1515/BC.2009.033 Bernstein PS, Li B, Vachali PP, Gorusupudi A, Shyam R, Henriksen BS, Nolan JM (2016) Lutein, zeaxanthin, and meso-zeaxanthin: the basic and clinical science underlying carotenoid-based nutritional interventions against ocular disease. Prog Retin Eye Res 50:34–66. https://doi. org/10.1016/j.preteyeres.2015.10.003 Bertolo RF, McBreairty LE (2013) The nutritional burden of methylation reactions. Curr Opin Clin Nutr Metab Care 16:102–108. https://doi.org/10.1097/MCO.0b013e32835ad2ee Björkblom B, Wibom C, Jonsson P, Mörén L, Andersson U, Johannesen TB, Langseth H, Antti H, Melin B (2016) Metabolomic screening of pre-diagnostic serum samples identifies association between α- and γ-tocopherols and glioblastoma risk. Oncotarget 7:37043–37053. https://doi. org/10.18632/oncotarget.9242 Bjørndal B, Bruheim B, Lysne V, Ramsvik MS, Ueland PM, Nordrehaug JE, Nygård OK, Berge RK (2018) Plasma choline, homocysteine and vitamin status in healthy adults supplemented with krill oil: a pilot study. Scan J Clin Lab Invest 78:527–532. https://doi.org/10.1080/00365 513.2018.1512716 Blusztajn JK, Mellott TJ (2013) Neuroprotective actions of perinatal choline nutrition. Clin Chem Lab Med 51:591–599. https://doi.org/10.1515/cclm-2012-0635 Blusztajn JK, Slack BE, Mellott TJ (2017) Neuroprotective actions of dietary choline. Nutrients 9:815. https://doi.org/10.3390/nu9080815 Booth SL (2009) Roles for vitamin K beyond coagulation. Annu Rev Nutr 29:89–110

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Campolo J, Bernardi S, Cozzi L, Rocchiccioli S, Dellanoce C, Cecchettini A, Tonini A, Parolini M, De Chiara B, Micheloni G, Pelosi G, Passino C, Giannattasio C, Parodi O (2017) Medium-­ term effect of sublingual L-glutathione supplementation on flow-mediated dilation in subjects with cardiovascular risk factors. Nutrition 38:41–47. https://doi.org/10.1016/j.nut.2016.12.018 Carver BF (ed) (2009) Wheat science and trade, Wiley-Blackwell. Ames, Iowa. https://onlinelibrary.wiley.com/doi/book/10.1002/9780813818832 Challem JJ (1999) Toward a new definition of essential nutrients: is it now time for a third ‘vitamin’ paradigm? Med Hypoth 52:417–422. https://doi.org/10.1016/j.bmcl.2011.10.117 Cheatham CL (2014) Mechanisms and correlates of a healthy brain: a commentary. Monog Society Res Child Develop 79:153–165. https://doi.org/10.1111/mono.12135 Choi IY, Lee P, Denney DR, Spaeth K, Nast O, Ptomey L, Roth AK, Lierman JA, Sullivan DK (2015) Dairy intake is associated with brain glutathione concentration in older adults. Am J Clin Nutr 101:287–293. https://doi.org/10.3945/ajcn.114.096701 Clarke FR, Clarke JM, McCaig TN, Knox RE, DePauw RM (2011) Inheritance of yellow pigment concentration in seven durum wheat crosses. Can J Plant Sci 86:133–141. https://doi. org/10.4141/p05-083 Cooney RV, Franke AA, Wilkens LR, Gill J, Kolonel LN (2008) Elevated plasma γ-tocopherol and decreased α-tocopherol in men are associated with inflammatory markers and decreased plasma 25-OH vitamin D. Nutr Cancer 60:21–29. https://doi.org/10.1080/01635580802404162 Corol DI, Ravel C, Raksegi M, Bedo Z, Charmet G, Beale MH, Shewry PR, Ward JL (2012) Effects of genotype and environment on the contents of betaine, choline, and trigonelline in cereal grains. J Agric Food Chem 60:5471–5481. https://doi.org/10.1021/jf3008794 Dagres N, Nieuwlaat R, Vardas PE, Andresen D, Lévy S, Cobbe S, Kremastinos DT, Breithardt G, Cokkinos DV, Crijns HJGM (2007) Gender-related differences in presentation, treatment, and outcome of patients with atrial fibrillation in Europe. J Am Coll Cardiol 49:572–577. https:// doi.org/10.1016/j.jacc.2006.10.047 Dietrich M, Jacques PF, Traber MG, Cross CE, Hu Y, Block G (2006) Does γ-tocopherol play a role in the primary prevention of heart disease and cancer? A review. J Am Coll Nutr 25:292– 299. https://doi.org/10.1080/07315724.2006.10719538 Dror Y, Stern F, Berner YN, Kaufmann NA, Berry E, Maaravi Y, Altman H, Cohen A, Leventhal A, Kaluski DN (2002) Recommended micronutrient supplementation for institutionalized elderly. J Nutr Health Aging 6:295–300 Dror Y, Stern F, Gomori MJ (2015) Vitamins in the prevention or delay of cognitive disability of aging. Curr Aging Sci 7:187–213. https://doi.org/10.2174/1874609808666150201214955 Dror Y, Giveon SM, Stern F (2018) The nadir range of the U-shaped curve chap 11. In: Malavolta M, Mocchegiani E (eds) Trace elements and minerals in health and longevity, Series Rattan SIS (Ed) healthy ageing and longevity, vol 8. Springer, Cham, pp  303–325. https://doi. org/10.1007/978-3-030-03742-0/ Du YF, Lin FY, Long WQ, Luo WP, Yan B, Xu M, Mo XF, Zhang CX (2017) Serum betaine but not choline is inversely associated with breast cancer risk: a case–control study in China. Eur J Nutr 56:1329–1337. https://doi.org/10.1007/s00394-016-1183-3 Edwards JA (2016) Zeaxanthin: review of toxicological data and acceptable daily intake. J Ophthalmol 2016:3690140, 1–15. https://doi.org/10.1155/2016/3690140 Eggersdorfer M, Wyss A (2018) Carotenoids in human nutrition and health. Arch Biochem Biophys 652:18–26. https://doi.org/10.1016/j.abb.2018.06.001 Fardet A, Rock E, Remesy C (2008) Is the in vitro antioxidant potential of whole-grain cereals and cereal products well reflected in vivo? J Cereal Sci 48:258–276. https://doi.org/10.1016/j. jcs.2008.01.002 Fardet A, Canlet C, Gottardi G, Lyan B, Llorach R, Rémésy C, Mazur A, Paris A, Scalbert A (2018) Whole-grain and refined wheat flours show distinct metabolic profiles in rats as assessed by a 1H NMR-based metabonomic approach. J Nutr 137:923–929. https://doi.org/10.1093/ jn/137.4.923 Filipcev B, Kojic J, Krulj J, Bodroža-Solarov M, Ilic N (2018) Betaine in cereal grains and grain-­ based products. Foods 7:49. https://doi.org/10.3390/foods7040049

References

169

Ford ES, Schleicher RL, Mokdad AH, Ajani UA, Liu S (2006) Distribution of serum concentrations of α-tocopherol and γ-tocopherol in the US population. Am J Clin Nutr 84:375–383. https://academic.oup.com/ajcn/article-abstract/84/2/375/4649602 Fratianni A, Giuzio L, Di Criscio T, Flagella Z, Panfili G (2013) Response of carotenoids and tocols of durum wheat in relation to water stress and sulfur fertilization. J Agric Food Chem 61:2583–2590. https://doi.org/10.1021/jf304168r Gao X, Wang Y, Randell E, Pedram P, Yi Y, Gulliver W, Sun G (2016) Higher dietary choline and betaine intakes are associated with better body composition in the adult p­opulation of Newfoundland, Canada. PLoS One 11:e0155403. https://doi.org/10.1371/journal. pone.0155403 Giustarini D, Colombo G, Garavaglia ML, Astori E, Portinaro NM, Reggiani F, Badalamenti S, Aloisi AM, Santucci A, Rossi R, Milzani A, Dalle-Donne I (2017) Assessment of glutathione/glutathione disulphide ratio and S-glutathionylated proteins in human blood, solid tissues, and cultured cells. Free Radic Biol Med 112:360–375. https://doi.org/10.1016/j. freeradbiomed.2017.08.008 Graham RD, Rosser JM (2000) Carotenoids in staple foods: their potential to improve human nutrition. Food Nutr Bull 21:404–409 Graham SF, Hollis JH, Migaud M, Browne RA (2009) Analysis of betaine and choline contents of aleurone, bran, and flour fractions of wheat (Triticum aestivum L.) using 1H nuclear magnetic resonance (NMR) spectroscopy. J Agric Food Chem 57:1948–1951. https://doi.org/10.1021/ jf802885m Grilo EC, Costa PN, Santos C, Gurgel CSS, Beserra AFDL, Almeida FNDS, Dimenstein R (2014) Alpha-tocopherol and gamma-tocopherol concentration in vegetable oils. Food Sci Technol 34:379–385. https://doi.org/10.1590/S0101-20612014005000031 Harris E, Macpherson H, Vitetta L, Kirk J, Sali A, Pipingas A (2012) Effects of a multivitamin, mineral and herbal supplement on cognition and blood biomarkers in older men: a randomised, placebo-controlled trial. Hum Psychopharmacol Clin Exp 27:370–377. https://doi.org/10.1002/ hup.2236 Hasanuzzaman M, Nahar K, Anee TI, Fujita M (2017) Glutathione in plants: biosynthesis and physiological role in environmental stress tolerance. Physiol Mol Biol Plants 23:249–268. https://doi.org/10.1007/s12298-017-0422-2 Hefni ME, Witthöft CM, Moazzami AA (2018) Plasma metabolite profiles in healthy women differ after intervention with supplemental folic acid v. folate-rich foods. J Nutr Sci 7:e32. https://doi. org/10.1017/jns.2018.22 Hentschel V, Kranl K, Hollmann J, Lindhauer MG, Böhm V, Bitsch R (2002) Spectrophotometric determination of yellow pigment content and evaluation of carotenoids by high-performance liquid chromatography in durum wheat grain. J Agric Food Chem 50:6663–6668. https://doi. org/10.1021/jf025701p HMDB: http://www.hmdb.ca/hml Humphries JM, Khachik F (2003) Distribution of lutein, zeaxanthin, and related geometrical isomers in fruit, vegetables, wheat, and pasta products. J Agric Food Chem 51:1322–1327. https:// doi.org/10.1021/jf026073e.i Johnson EJ (2014) Role of lutein and zeaxanthin in visual and cognitive function throughout the lifespan. Nutr Rev 72:605–612. https://doi.org/10.1111/nure.12133 Julkunen-Tiitto R, Nenadis N, Neugart S, Robson M, Agati G, Vepsäläinen J, Zipoli G, Nybakken L, Winkler B, Jansen MAK (2015) Assessing the response of plant flavonoids to UV radiation: an overview of appropriate techniques. Phytochem Rev 14:273–297. https://doi.org/10.1007/ s11101-014-9362-4 Kalmar ID, Verstegen MWA, Maenner K, Zentek J, Meulemans G, Janssens GPJ (2012) Tolerance and safety evaluation of N,N-dimethylglycine, a naturally occurring organic compound, as a feed additive in broiler diets. Br J Nutr 107:1635–1644. https://doi.org/10.1017/ S0007114511004752 Kirkpatrick SI, Tarasuk V (2008) Food insecurity is associated with nutrient inadequacies among Canadian adults and adolescents. J Nutr 138:604–612. https://doi.org/10.1093/jn/138.3.604

170

8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

Konstanti-nova SV, Tell GS, Vollset SE, Arve Ulvik A, Drevon CA, Ueland PM (2008) Dietary patterns, food groups, and nutrients as predictors of plasma choline and betaine in middle-­ aged and elderly men and women. Am J Clin Nutr 88:1663–1669. https://doi.org/10.3945/ ajcn.2008.26531 Labuschagne MT, Mkhatywa N, Wentzel B, Johansson E, van Biljon A (2014) Tocochromanol concentration, protein composition and baking quality of white flour of South African wheat cultivars. J Food Compos Anal 33:127–131. https://doi.org/10.1016/j.jfca.2013.12.003 Labuschagne M, Mkhatywa N, Johansson E, Wentzel B, Biljon AV (2017) The content of tocols in South African wheat; impact on nutritional benefits. Foods 6:95. https://doi.org/10.3390/ foods6110095 Lachman J, Hejtmánková K, Kotíková Z (2013) Tocols and carotenoids of einkorn, emmer and spring wheat varieties: selection for breeding and production. J Cereal Sci 57:207–214. https:// doi.org/10.1016/j.jcs.2012.05.011 Lachman J, Hejtmánková A, Orsák M, Popov M, Martinek P (2018) Tocotrienols and tocopherols in colored-grain wheat, tritordeum and barley. Food Chem 240:725–735. https://doi. org/10.1016/j.foodchem.2017.07.123 Leermakers ETM, Moreira EM, Kiefte-de JJC, Darweesh SKL, Visser T, Voortman T, Bautista PK, Chowdhury R, Gorman D, Bramer WM, Felix JF, Franco OH (2015) Effects of choline on health across the life course: a systematic review. Nutr Rev 73:500–522. https://doi. org/10.1093/nutrit/nuv010 Lever M, Slow S (2010) The clinical significance of betaine, an osmolyte with a key role in methyl group metabolism. Clin Biochem 43:732–744. https://doi.org/10.1016/j. clinbiochem.2010.03.009 Likes R, Madl RL, Zeisel SH, Craig SAS (2007) The betaine and choline content of a whole-­ wheat flour compared to other mill streams. J Cereal Sci 46:93–95. https://doi.org/10.1016/j. jcs.2006.11.002 Lipiński K, Mazur M, Antoszkiewicz Z, Purwin C (2017) Polyphenols in monogastric nutrition - a review. Ann Anim Sci 17:41–58. https://doi.org/10.1515/aoas-2016-0042 Loo-Bouwman CAV, Naber THJ, Schaafsma G (2014) A review of vitamin a equivalency of β-carotene in various food matrices for human consumption. Br J Nutr 111:2153–2166. https:// doi.org/10.1017/S0007114514000166 Ly J, Lagman M, Saing T, Singh MK, Tudela EV, Morris D, Anderson J, Daliva J, Ochoa C, Patel N, Pearce D, Venketaraman V (2015) Liposomal glutathione supplementation restores TH1 cytokine response to mycobacterium tuberculosis infection in HIV-infected individuals. J Interf Cytokine Res 35:875–887. https://doi.org/10.1089/jir.2014.0210 Magariño M, Mateo CM, Nolasco SM (2015) Kinetics of tocopherol degradation during the storage of wheat germ oil. Can J Chem Eng 93:1999–2004. https://doi.org/10.1002/cjce.22316 Malekbala MR, Soltani SM, Hosseini S, Babadi FE, Malekbala R (2017) Current technologies in the extraction, enrichment and analytical detection of tocopherols and tocotrienols: a review. Crit Rev Food Sci Nutr 57:2935–2942. https://doi.org/10.1080/10408398.2015.1020532 Mangialasche F, Westman E, Kivipelto M, Muehlboeck J-S, Cecchetti R, Baglioni M, Tarducci R, Gobbi G, Floridi P, Soininen H, Kłoszewska I, Tsolaki M, Vellas B, Spenger C, Lovestone S, Wahlund L-O, Simmons A, Mecocci P (2013) Classification and prediction of clinical diagnosis of Alzheimer’s disease based on MRI and plasma measures of α-/γ-tocotrienols and γ-tocopherol. J Intern Med 273:602–621. https://doi.org/10.1111/joim.12037 Manikandan R, Thiagarajan R, Goutham G, Arumugam M, Beulaja M, Rastrelli L, Skalicka-­ Woźniak K, Habtemariam S, Orhan IE, Nabavi SF, Nabavi SM (2016) Zeaxanthin and ocular health, from bench to bedside. Fitoterapia 109:58–66. https://doi.org/10.1016/j. fitote.2015.12.009 Manor D, Morley S (2007) The α-tocopherol transfer protein. Vitam Horm 76:45–65. https://doi. org/10.1016/S0083-6729(07)76003-X Marchese ME, Kumar R, Colangelo LA, Avila PC, Jacobs DR, Gross M, Sood A, Liu K, Cook-­ Mills JM (2014) The vitamin E isoforms α-tocopherol and γ-tocopherol have opposite asso-

References

171

ciations with spirometric parameters: the CARDIA study. Respir Res 15:31. https://doi. org/10.1186/1465-9921-15-31 Mares J (2016) Lutein and zeaxanthin isomers in eye health and disease. Annu Rev Nutr 36:571– 602. https://doi.org/10.1146/annurev-nutr-071715-051110 Mayne ST (1996) Beta-carotene, carotenoids,and disease in humans. FASEB J 10:690–701 Mellado-Ortega E, Hornero-Méndez D (2015) Carotenoids in cereals: an ancient resource with present and future applications. Phytochem Rev 14:873–890. https://doi.org/10.1007/ s11101-015-9423-3 Mellado-Ortega E, Hornero-Méndez D (2017) Lutein esterification in wheat flour increases the carotenoid retention and is induced by storage temperatures. Foods 6:111. https://doi. org/10.3390/foods6120111 Mohajeri MH, Troesch B, Weber P (2015) Inadequate supply of vitamins and DHA in the elderly: implications for brain aging and Alzheimer-type dementia. Nutrition 31:261–275. https://doi. org/10.1016/j.nut.2014.06.016 Mustacich DJ, Bruno RS, Traber MG (2007) Vitamin E. Vit Horm 76:1–21. https://doi.org/10.1016/ S0083-6729(07)76001-6 Olmedilla B, Granado F, Blanco I, Vaquero M, Cajigal C (2001) Lutein in patients with cataracts and age-related macular degeneration: a long-term supplementation study. J Sci Food Agric 81:904–909. https://doi.org/10.1002/jsfa.905 Paznocht L, Kotíková Z, Šulc M, Lachman J, Orsák M, Eliášová M, Martinek P (2018) Free and esterified carotenoids in pigmented wheat, tritordeum and barley grains. Food Chem 240:670– 678. https://doi.org/10.1016/j.foodchem.2017.07.151 Pfande H (1992) Carotenoids: an overview. Meth Enzymol 213:3–13 Ranard RM, Erdman JW (2017) Effects of dietary RRR α-tocopherol vs all-racemic α-tocopherol on health outcomes. Nutr Rev 76:141–153. https://doi.org/10.1093/nutrit/nux067 Richie JP, Nichenametla S, Neidig W, Calcagnotto A, Haley JS, Schell TD, Muscat JE (2015) Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr 54:251–263. https://doi.org/10.1007/s00394-014-0706-z Roberts JE, Dennison J (2015) The photobiology of lutein and zeaxanthin in the eye. J Ophthalmol 2015:687173. https://doi.org/10.1155/2015/687173 Rodriguez-Amaya DB (2016) Food carotenoids: chemistry, biology, and technology, 1st edn. Wiley, Chichester, West Sussex, UK Ross AB, Zangger A, Guiraud SP (2014) Cereal foods are the major source of betaine in the Western diet - analysis of betaine and free choline in cereal foods and updated assessments of betaine intake. Food Chem 145:859–865. https://doi.org/10.1016/j.foodchem.2013.08.122 Schulthess A, Schwember AR (2014) Improving durum wheat (Triticum turgidum L. var durum) grain yellow pigment content through plant breeding. Cien Inv Agr 40:475–490. https://doi. org/10.4067/s0718-16202013000300002 Schuppan D, Zevallos V (2015) Wheat amylase trypsin inhibitors as nutritional activators of innate immunity. Dig Dis 33:260–263. https://doi.org/10.1159/000371476 Sechi GP, Sechi E, Fois C, Kumar N (2016) Advances in clinical determinants and neurological manifestations of B vitamin deficiency in adults. Nutr Rev 74:281–300. https://doi.org/10.1093/ nutrit/nuv107 Shahidi F, Camargo ACD (2016) Tocopherols and tocotrienols in common and emerging dietary sources: occurrence, applications, and health benefits. Int J Mol Sci 17:1745. https://doi. org/10.3390/ijms17101745 Shrader WD, Amagata A, Barnes A, Hinman A, Jankowski O, Lee E, Kheifets V, Komatsuzaki R, Mollard P, Murase K, Rioux P, Wesson K, Miller G (2012) Towards a modern definition of vitamin E–evidence for a quinone hypothesis. Bioorg Med Chem Lett 22:391–395. https://doi. org/10.1016/j.bmcl.2011.10.117 Smolikova GN, Medvedev SS (2015) Seed carotenoids: synthesis, diversity, and functions. Russ J Plant Physiol 62:1–13. https://doi.org/10.1134/s1021443715010136

172

8  The Vitamins and the Organic Micronutrients in the Wheat Kernel

Tea I, Genter T, Violleau F, Kleiber D (2005) Changes in the glutathione thiol-disulfide status in wheat grain by foliar sulphur fertilization: consequences for the rheological properties of dough. J Cereal Sci 41:305–315. https://doi.org/10.1016/j.jcs.2004.10.003 Traber MG (2004) Vitamin E.  Encycl Diet Suppl 76:757–769. https://doi. org/10.1081/E-EDS-120022054 Wagner KH, Kamal-Eldin A, Elmadfa I (2004) Gamma-tocopherol - an underestimated vitamin? Ann Nutr Metab 48:169–188. https://doi.org/10.1159/000079555 Wallace TC, Fulgoni VL (2016) Assessment of total choline intakes in the United States. J Am Coll Nutr 35:108–112. https://doi.org/10.1080/07315724.2015.1080127 Whent M, Huang H, Xie Z, Lutterodt H, Yue L, Fuerst EP, Morris CF, Yu L, Luthria D (2012) Phytochemical composition, anti-inflammatory, and antiproliferative activity of whole-wheat flour. J Agric Food Chem 60:2129–2135. https://doi.org/10.1021/jf203807w Ying J, Rahbar MH, Hallman DM, Hernandez LM, Spitz MR, Forman MR, Gorlova OY (2013) Associations between dietary intake of choline and betaine and lung cancer risk. PLoS One 8:8–e54561. https://doi.org/10.1371/journal.pone.0054561 Yonemori KM, Lim U, Koga KR, Wilkens LR, Au D, Boushey CJ, Le Marchand L, Kolonel LN, Murphy SP (2013) Dietary choline and betaine intakes vary in an adult multiethnic population. J Nutr 143:894–899. https://doi.org/10.3945/jn.112.171132 Zeisel SH (2000) Choline: an essential nutrient for humans. Nutrition 16:669–671. https://doi. org/10.1016/S0899Zeisel SH (2017) Choline, other methyl-donors and epigenetics. Nutrients 9:445. https://doi. org/10.3390/nu9050445 Zeisel SH, Costa KAD, Franklin PD, Alexander EA, Lamont JT, Sheard NF, Beiser R (1991) Choline, an essential nutrient for humans. FASEB 5:2093–2098 Zhang W, Lukaszewski AJ, Kolmer J, Soria MA, Goyal S, Dubcovsky J (2005) Molecular characterization of durum and common wheat recombinant lines carrying leaf rust resistance (Lr19) and yellow pigment (Y) genes from Lophopyrum ponticum. Theor Appl Genet 111:573–582. https://doi.org/10.1007/s00122-005-2048-y Zhang M, Ma D, Wang C, Zhao H, Zhu Y, Guo T (2016) Responses of amino acid composition to nitrogen application in high- and low-protein wheat cultivars at two pl-g environments. Crop Sci 56:1277–1287. https://doi.org/10.2135/cropsci2015.08.0504 Zielińska MA, Wesołowska A, Pawlus B, Hamułka J (2017) Health effects of carotenoids during pregnancy and lactation. Nutrients 9:838. https://doi.org/10.3390/nu9080838

Chapter 9

The Anti-oxidants

Within all the period of human existence, he consumed considerable amounts of anti-oxidants. The urbanization has reduced remarkably the availability of food items containing high levels of anti-oxidant compounds. Still human, in the within then societies, acquired considerable amounts of the precocious anti-oxidant compounds from the whole-wheat products not until the industrial revolution when more and more wheat flour was refined with a mark reduction in the anti-oxidant content. The natural anti-oxidants present in food and other biological material have received considerable interest because of their safety and potential nutritional and therapeutic effects. The anti-oxidants can scavenge the free radicals before they cause damage, or prevent the oxidative damage from spreading. Although bioactive compounds present in virtually all plant foods, their levels may vary considerably among diets depending on the type and the quantity of the plant constituents in the diet. The cereals are widely consumed and are a valuable means of delivering beneficial natural anti-oxidants to humans. The anti-oxidant capacity of the wheat kernel produced by different compounds of the hydrophilic and the lipophilic types (Hejtmánková et al. 2010). The bread wheat with the highest genome capacity has presumably a very high capacity to synthesize a wide repertoire of the anti-oxidants and the other minor ingredients that have enabled the wheat cultivar to spread over the global areas at the ranges and conditions, wider than for any other cultivar. The diet rich in natural anti-oxidants can have a significant impact upon the increases in the reactive anti-­ oxidant potential of an organism, and reduce the risk of the diseases of the free radical origin. The adequate dietary anti-oxidants such as bioactive phenols, ascorbate, tocopherols, and carotenoids induce the immune system, increase the defensive abilities of the cells, produces diverse beneficial bioactivities, including anti-­ allergic, antiviral, anti-inflammatory, and anti-mutagenic properties. The phenolic acids comprise the main anti-oxidant capacity in the cereal grains and exist in free, soluble conjugated and bound forms, where the bound form represents the major proportion of the phenolic acids (Dziki et al. 2014). To avoid the potential damage © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_9

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to the wheat cultivar caused by the reactive oxygen species (ROS) to the cellular components, as well as to maintain growth, metabolism, development, and overall productivity, the balance between production and elimination of the ROS at the intracellular level must be tightly regulated and/or efficiently metabolized. The equilibrium between the production and the detoxification of the ROS sustained by the enzymatic and the non-enzymatic anti-oxidants. The main types of stresses include salt, drought, water excess, UV-B radiation, cold, heat, pathogens, insects, chemicals, ozone, and nutrient deprivation. Under stress, plant development and reproduction may affect at different levels of severity. Furthermore, the stress maximized when it occurs in combination (Caverzan et al. 2016). The survival of the human clad has at least, partially supported in many global areas by the magnificent virtue of the wheat to accumulate tens and hundreds of the micronutrient ingredients that except protecting the wheat cultivar, transferred their valuable ingredients into the human gut. The ferulic acid comprises the main polyphenol quantity in the wheat kernel but many other ingredients are acting in all the human biochemical pathways after being absorbed into the bloodstream.

Reactive Oxygen Species (ROS) The reactive oxygen species present a paradox in their biological function. On one hand, they prevent disease by assisting the immune system, by the mediating of the cell signaling and playing an essential role in apoptosis. On the other hand, they can damage the important macromolecules in the cell and may have a role in the carcinogenesis and the coronary vascular diseases. The generation of the reactive oxygen species is a normal physiological process, particularly for proper immunocompetence and in coordination and activation of numerous signal transduction pathways. The formation of the reactive oxygen species is a natural consequence of aerobic metabolism and is integral for maintaining tissue oxygen homeostasis. When oxygen homeostasis not maintained, the cellular environment has become oxidatively stressed. Normally, ~1–3% of the oxygen consumed converted into the reactive oxygen species. Potentially, damaging oxidative stress can generate by the excess of the reactive oxygen species, which kept in check by the endogenous cellular anti-­ oxidant mechanisms. The reactive oxygen species are reactive chemical species containing oxygen. Examples include peroxides, superoxide, hydroxyl radical, and singlet oxygen. In a biological context, reactive oxygen species formed as a natural byproduct of the normal metabolism of the oxygen and have important roles in the cell signaling and the homeostasis. However, during the times of the environmental stress (such as UV or heat exposure), the reactive oxygen species levels can increase dramatically. This may result in significant damage to the cell structures (Seifried et al. 2007). The oxidative stress emerges from an enhanced ROS/RNS generation or from a decay of the anti-oxidant protective ability, characterized by the reduced capacity of the endogenous systems to fight against the oxidative attack directed

The Sterols

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towards target biomolecules. Its severity is associated with several pathologies like cardiovascular, cancer and aging. The oxidative stress correlated with >100 diseases, either as the source or as the outcome. An irreversible progression of the oxidative decay caused by the reactive oxygen species also exerts its negative influence on the status of the biology of aging, consisting in the impairment of the physiological functions, promoting disease incidence, and reducing the lifespan (Pisoschi and Pop 2015).

The Sterols The sterols, also known as steroid alcohols, are a subgroup of the steroids and a class of organic molecules. Cholesterol is the most familiar type of animal sterol. The cholesterol vital to the construction of the membrane of the animal cell, and function, and used as a precursor to the fat-soluble vitamins and the steroid hormones. This compound belongs to the class of the organic compounds known as 3-hydroxysteroids. These are steroids carrying a hydroxyl group at the 3-position of the steroid backbone. In the Western diets, cereals and vegetable oils are the two most important sources of the natural dietary plant sterols. The contents of the plant sterols, as well as the other bioactive components, are the highest in the germ and in bran. The cereals have a somewhat different composition of the sterols and the stearyl conjugates when compared to the oilseeds and vegetables. As in most plant materials, in the cereals, the sitosterol (Figs. 9.1 and 9.2) and the campesterol (Fig. 9.3) are the most common sterols. However, contents of their saturated counterparts, the sitostanol, and the campestanol are much higher in the cereals than in the other vegetables. The pheno-

MW 248 Fig. 9.1  The sterol, total sterols: 640 μg/g in the wheat kernel (Table 8.2). The sterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of the organic molecules. They occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol. The cholesterol is vital to animal cell membrane structure and function, and the precursor to fat-soluble vitamins and steroid hormones (HMDB)

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Fig. 9.2  β-sitosterol: 360 μg/g in the wheat kernel (Table 8.2), shown in two graphical presentations. β-sitosterol is a phytosteros (plant sterol) with similar to the cholesterol structure. Sitosterols are white, waxy powders with a characteristic odor. They are hydrophobic and soluble in alcohols

Fig. 9.3  The campestanol, 53 μg/g in the wheat kernel (Table 8.2), shown in two graphical presentations. The campestanol is the plant stanol. It can decrease the circulating LDL-cholesterol level by the reducing of the intestinal cholesterol absorption (HMDB)

lic acid esters of the sterols found in significant quantities mainly in the cereals. The cereals also contain substantial amounts of the glycosylated sterols that found in other types of plant materials (Nyström et al. 2007). The plant sterols are C28 and C29 carbon steroid alcohols that are integral components of the plant cell membranes, have shown to be the key components of the plant plasma membrane microdomains and may exert similar functions in the human cells. These compounds cannot synthesize by humans and introduced through the diet where they found concentrated in the plant foods, especially those that are rich lipids. While a variety of the plant sterols such as campesterol, stigmasterol, and β-sitosterol are the most abundant pla4nt sterols in the diet, the prevalence of β-sitosterol being particularly noteworthy. Globally, dietary intake of these compounds has estimated at a range of 200–400 mg/d, making their intake similar in quantity to the cholesterol. The plant sterols exist in both the sterol and the stanol forms, with the bioavailability of sterols and their dietary prevalence exceeding that of the plant stanols. However, despite the

The Stanols

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relatively strong evidence for a beneficial effect of these c­ ompounds on the risk of cardiovascular disease. These compounds have received comparably little attention concerning their potential role in cancer etiology. The increasing evidence of the biochemical and molecular effects of plant sterols may make them strong candidates for cancer therapy (Grattan 2013). In humans consuming solid food diets, more than 90% of the sitosterol recovered in the stool. Plant sterol absorption is quite low, particularly for stanols, for which the absorption efficiency is over ten times lower than for the equivalent sterols. The plant sterols are very effective in lowering serum total and low-density lipoprotein cholesterol (Zawistowski and Jones 2015). The whole-wheat flour contains a higher content of the sterols and the stanols than the refined flour. The wheat germ concentrations of the phytosterols are (et  al. 201) (μg/g): α-sitosterol 2280, campesterol 790, stigmasterol 39, avenasterol 160, sitostanol 69, campestanol 127, and more than 8 unknown sterols (Phillips et al. 2005) (Fig. 9.4).

The Stanols The plant stanols are present in small amounts in the human diet. Their main sources are whole-grain foods, mostly wheat, and rye. The daily intake of stanols in the average Western diet is ~60 mg/d, whereas the intake of plant sterols is 150–300 mg/d and that of cholesterol is 500–800  mg/d. The relatively low natural levels of the stanols in the diet are too low to have a significant effect on the serum cholesterol levels. The plant sterols have traditionally considered non-absorbable. Hmdb.

Fig. 9.4  The stigmastanol, 37 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. The stigmastanol is a plant stanol. It can decrease the circulating LDL-­ cholesterol level (HMDB)

OH

MW 417

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9  The Anti-oxidants

The Role of the Phenolic Acids in the Plant Survival The accumulation of the phenolics in the plant tissues considered as an adaptive response to the adverse environmental conditions (Radchuk and Borisjuk 2014). The plant phenols constitute a standout among the most common and widespread group of the defensive compounds, which play an important role in host plant resistance against herbivores, including insects. The qualitative and the quantitative modifications in the phenols and the elevation in the activities of the oxidative enzyme in response to insect attack is a general phenomenon. Oxidation of the phenols catalyzed by the polyphenol oxidase and the peroxidase is a potential defense mechanism in plants against the herbivorous insects. The various biochemical changes caused by the infestation of the aphids in bread wheat varieties during the crop development are most important in the light of the pest effect on plant development. The phenolic acids are known to contribute significantly to the total anti-oxidant activity of the wheat. The increase in the phenol content after the infestation of the aphids in different wheat genotypes shows their effect. The elevation of the phenols could explain as a mechanism of the defense that acts as a barrier to insect feeding. The phenolic compounds are known to inhibit larval development and growth by acting as the feeding deterrents. The phenolic compounds induced in the plants are either directly toxic to insects or mediate the signaling of various transduction pathways, which in turn produce the toxic secondary metabolites and activate defensive enzymes. The quinones formed by the oxidation of the phenols bind covalently to the leaf proteins and inhibit protein digestion in the herbivores. An increase in the tannins after the aphid feeding indicated that the tannins might play a role in feeding deterrents. The can interact with the proteins suggesting that the tannins affected insect herbivores by the inactivating insect enzymes as well as the dietary proteins. The condensed tannins reduce the growth and the survival of many pests as they precipitate proteins nonspecifically by hydrogen bonding or covalent bonding with proteins, thereby reducing the nitrogen mineralization and/or digestion in the herbivore midgut (Kaur et al. 2017). The phenolic concentration of the wheat kernel has a pivotal role in the quality of the whole-wheat kernel. Particular attention should be paid for the factors affecting the phenolic concentrations. Phenolic concentration in the wheat kernel might highly be affected by the exposure to pest attack and the inoculation of effective microorganisms. The high variability in the phenolic compounds (as presented in Table 7.2) and the other antioxidants gallery present in the wheat kernel shows the high defense capability of the wheat. However, for such a wide range of the defense compounds the plant should maintain the burden of many enzymatic systems with the control elements embedded in any metabolic pathway. Through the evolutionary trait, the plethora of the defense compound has presumably a marked advantage on defense mechanisms containing only limited defensive compounds.

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The Phenolic Compounds Polyphenols are widespread metabolites found in various amounts of fruits, vegetables, cereals, and beverages. They all have in common one or several phenol groups in their structure capable of reducing the reactive oxygen species. This property is at the origin of their widely documented anti-oxidant properties and the considerable interest paid to their role in the prevention of chronic diseases. Commonly ~1  g/d of polyphenols ingested with foods and thus the polyphenols are the most abundant anti-oxidants in the diet. Several thousand polyphenols have characterized in plants, and several hundred polyphenols have found in foods. They vary widely in their hydroxylation pattern and can be glycosylated and/or acylated (Pérez-­Jiménez et al. 2010). The whole-wheat bread has a major role in the polyphenol supplementation because when it consumed properly with >30% of the total energy, it supplies >half of the dietary polyphenols. Unfortunately, the dietary polyphenols, as well as the total anti-oxidant capacity are not considered as an ingredient with a mandatory food-labeling item (FDA 2013), even the adequate polyphenol intake is a cornerstone of any system of sensible nutrition. Even voluntary foodlabeling, of such ingredients, has presumably nowhere practiced. Because the wheat products supply the main content of the dietary polyphenols, a reasonable presentation of the polyphenols content in the bakery products may provide us with the major information needed for the maintaining of the sensible nutrition (Fig. 9.5). The plant polyphenols synthesize via the shikimic acid pathway, the phenylpropanoid pathway, and the flavonoid pathway. The phenylalanine is the precursor of the phenolic acid. The phenylalanine is an aromatic amino acid that deaminated in the presence of phenylalanine ammonia-lyase that is a key enzyme of this pathway to produce the trans-cinnamic acid. The trans-cinnamic acid is further acted upon by the enzyme, cinnamate- 4-hydroxylase, to produce the p-coumaric acid. Thus, it gives rise to all of the other phenolic compounds and their derivatives such as phenolic acids, flavonoids, coumarins, and the lignans (Sharma et al. 2016).

MW 165 C9H11NO2 Fig. 9.5  The phenylalanine. The phenylalanine a is non-polar molecule because of the inert and hydrophobic nature of the benzyl side chain. Is an essential amino acid and the precursor of some compounds such as tyrosine, the monoamine neurotransmitters dopamine, norepinephrine, and epinephrine, and the skin pigment melanin. In plants, the phenylalanine is a precursor for the phenolic acid synthesis

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The phenolic acid present in high concentrations in the aleurone cell walls, in the seed coat, and in the embryo of the wheat, which removed during milling but is not present in significant quantities in the starchy endosperm. Thermal processing generally considered essentially destructive to nutrients, because most of the bioactive compounds become unstable when exposed to heat. Therefore, heat-processed foods considered having less health-promoting capacity than fresh foods. As phenolic acids are susceptible to oxidation and degradation, exposure to the light, oxygen, and heat, conditions normally present during food processing, may accelerate the destruction of the phenolic acids. Therefore, information on the stability of phenolic acids during food processing is important for the evaluating of the potential health benefits of the foods containing the phenolic acids. In some certain conditions like baking, the phenolic acids retain their anti-oxidant activity after the baking process, which has potential health benefits (Han and Koh 2011). The plants produce varying forms of polyphenols, a large, diverse class of compounds, many with anti-oxidant properties. Structurally, polyphenols all have one or more aromatic (phenolic) rings with different structural elements that allow classification into subgroups. The anti-oxidants defined as compounds that, at low concentration, can delay or prevent the oxidative damage of substrates as DNA, enzymes and cell wall molecules and neutralizing the free radicals. The polyphenols are one of the most complex and representative group of the phytochemicals in the wheat kernel (Dinelli et al. 2011). The polyphenols are abundant micronutrients in our diet, and evidence for their role in the prevention of the NCD (Non-Communicable Diseases) is emerging. The health effects of the polyphenols depend on the amount consumed and on their bioavailability. The anti-oxidant properties of the polyphenols, their great abundance, and their probable role in the prevention of the various diseases associated with the oxidative stress have led to the intensive interest of their role in our diet. Not all polyphenols absorbed with equal efficacy. They extensively metabolized by the intestinal and the hepatic enzymes and by the colon microbiota. The information about the bioavailability and the metabolism of the various polyphenols is necessary to evaluate their biological activity within the target tissues. Generally, the polyphenols molecules involved in the defense against the ultraviolet radiation or the pathogen aggressions. The phenolic compounds classified into different groups according to the function of the number of the phenol rings that they contain and the structural elements that bind these rings to one another. Distinctions thus made between the phenolic acids, flavonoids, stilbenes, and lignans. The polyphenols also associated with various carbohydrates and organic acids contain anti-oxidants such as phenolic present in free and the bound forms while the majority are insoluble, bound by ester and ether linkages with polysaccharide in the cell wall while a smaller portion is soluble, that is free phenolics (Manach et al. 2004). The bound phenolics considered to have a greater anti-oxidant capacity because they escape from the gastrointestinal digestion along with the cell wall materials and are absorbed into the blood plasma during the fermentation by the colon microflora. The phenolic acids represent the most common compounds of phenolics in wheat, with the ferulic acid as the most abundant (Nikolić et al. 2016). The phenolic acids play diverse roles, functioning as

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signaling molecules, the agents in the plant defense, and the regulators of the auxin transport. Most studies of the plant phenolics have focused on examining these compounds in vegetables and fruits. Many types of the phenolic compounds that found in fruits and vegetables also found in cereals. The total anti-oxidant activity of whole-grain products is similar to that of fruits or vegetables on a per-serving basis (Ma et al. 2016). Some main phenolic ingredients have presented in Table 8.2 but many minor such compounds are observed in the wheat kernels (Dinelli et al. 2011). With the huge genome embedded in the wheat kernel, hundreds of active biological compounds accumulated in the kernel. The majority of the phenolic acids bounded to carbohydrate moieties, some of the phenolic acids conjugated and some are free ingredients. The major phenolic acids in the wheat kernel (Table 8.2) with their relative concentrations are ferulic acid 1.0; syringic acid 0.37; dihydroxybenzoic acid 0.23; and synaptic acid 0.13. These ratios changed in other data and samples. The predominance of the phenolic acids differs between the grain species. The list of the phenolic anti-oxidants in the cereals, cannot tell us which cereal crop has the most powerful activity to protect us from the hazardous effects of the free radicals or other hazardous compounds. We cannot define which crop better scavenge free radicals or better enhances cellular autophagy. This process is most important in the preserving of brain integrity but also preserves the integrity of other human tissues. Such a description may explain that the diversity of the crops is very high and that there is a wide room to investigate their effects and to develop sophisticated cereal varieties for the promotion of human health. Presently the golden ruler for the evaluation of the protective effects of such compounds is the extensive epidemiological surveys but in such surveys, the effect of the specific variety or the specific crop cannot explore. The anti-oxidant capacity of the cereals has probably underestimated since the extraction procedures do not release all the anti-oxidant content (Fardet et al. 2008; Cohen-Zinder et al. 2017). The phenolic acids are the derivatives of benzoic and cinnamic acids and they present in all cereals with some specification for the wheat kernel concentrations, μg/g wheat kernel (Table 8.2) Total polyphenols content, 3000 The two classes of phenolic acids: (a) Hydroxybenzoic protocatechuic p-hydroxybenzoic, 110 salicylic vanillic, 18 syringic, 18 gallic genistic

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(b) Hydroxycinnamic Ferulic, 450 Caffeic, 17 Cinnamic, 27 p-coumaric, 28 synaptic, 93 o-coumaric m-coumaric The phenolic acids reported in cereals occur in free, conjugated and bound forms. The highest the intensity of the chemical reaction required to release the compound terms the phenolic as bound while moderate-intensity terms the phenolic conjugated. The free phenolic acids located in the outer layer of the pericarp and extracted using organic solvents. Bound phenolic acids esterified to the cell wall. Acid or base hydrolysis required to release them from the cell matrix. Ferulic compounds are the major phenolic acids in the wheat. The phenolic acids concentrations vary among the cereals and their brans that contained three fold of the kernel concentration (Dykes 2007). A phenolic compound contains, by definition, a benzene ring, with ≥1 hydroxyl group such as phenolic acids, flavonoids, tannins, coumarins, and alkylresorcinols. All plant-based foods contain phenols that affect their appearance, taste, odor, and stability (Dykes 2007). The non-covalent interactions between the starch and the phenolic compounds may have an impact on the physicochemical and nutritional properties of the food. The phenolic compound interacts to form either inclusion complex in the form of amylose single helices facilitated by the hydrophobic effect, or complex with much weaker binding most through hydrogen bonds (Zhu 2015). The total phytochemical content and the anti-oxidant activity of the whole-grains have commonly underestimated because of the bounding nature of these compounds in the cereal kernel. Most of the whole-grain phenolics are present in bound form, 85% in corn, 76% in wheat, and 75% in oats. The whole-grains contain unique phytochemicals that complete those in the fruits and the vegetables when consumed together (Liu 2007). The beneficial effects associated with the whole-grain consumption are in part due to the existence of the unique phytochemicals of the whole-grain. Thus, the anti-oxidant content of the whole-wheat bread might be one of the most interesting information in the nutritional labeling and nutritional evaluation. Even so, such information does not exist and thoroughly ignored. In most or all of the reviews describing the qualities of whole-wheat bread, the knowledge about the anti-oxidant content is absent. When the bread baked from the refined flour, the wheat processing through the long line of harvesting, storage, milling, and baking has a minor effect on the nutritional bread quality. The anti-oxidants are abundant in vegetables and fruits and found in grain cereals, peas, legumes, and nuts. At such a juncture, a systematic survey has identified >3100 anti-oxidants in foods, like beverages, spices, herbs and supplements which regularly consumed by different cultures. The decrease in the intake of anti-oxidants rich food may increase the chances of ­oxidative stress that may lead to the cell damage, therefore intake of such natural anti-­oxidants have considered giving a protective effect (Rajendran et al. 2014).

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183

The corn (maize) has the highest total phenolic content of gallic acid (15 μnole/g), followed by wheat (8), oats (6.5), and rice (5.6). The major portion of phenolics in grains existed in the bound form (62–85%). The bound phytochemicals have the major contributors to the total anti-oxidant activity in the range of 70–90%. Bound phytochemicals could survive the stomach and intestinal digestion to reach the colon (Adom and Liu 2002). The phenolic compounds have structures that vary from simple molecules to complex polymers. This relevant structural diversity influences their difference in bioavailability: simple phenolic acids (e.g. caffeic acid) more easily cross the intestinal barrier, while complex molecules (e.g. proanthocyanins) are scarcely absorbed (Brandolini et al. 2013).

Phenylpropiolic Acid The phenolics derived from the phenylpropanoids pathway. The significant differences observed between the cereal types, within varieties as well as within grain fractions (Fig. 9.6).

Specific Phenolic Acids The Ferulic Acid The ferulic acid (4-hydroxy-3-methoxycinnamic acid) is the most widespread hydroxycinnamic acid in the plant world, where it is a key molecule in the cell wall architecture. The ferulic acid cross-links with the polysaccharides and the

MW 146 Fig. 9.6  Phenylpropiolic acid, shown in two graphical esentations. Phenylpropiolic acid is one of several phenylpropanoid, natural products occurring in plants pathways involved in plant resistance providing building units of physical barriers against pathogen invasion, synthesizing an array of antibiotic compounds, and producing signals implicated in the mounting of plant resistance

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lignin (Fig. 7.8). The ferulic acid occurs etherified to lignin via its aromatic nucleus, coupling initially with both coniferyl and sinapyl alcohol monomers (Fig. 7.8) in ryegrass lignins. The ferulic acid also mediates polysaccharide-protein cross-links via the tyrosine and the cysteine residues. The polysaccharide– polysaccharide cross-­links are then mediated through the ferulic acid oligomers (Barberousse et al. 2008). The trans-ferulic acid is a phenolic acid that absorbed by the small intestine and excreted in the urine. The ferulic concentration varying from 5 mg/g in the wheat bran to 9 mg/g in the sugar-beet pulp and 50 mg/g in the corn kernel. It occurs primarily in the seeds and the leaves both, in the free form and covalently linked to lignin and other biopolymers. The ferulic acid usually found as ester cross-links with polysaccharides in the cell wall, such as arabinoxylans in grasses, pectin in spinach and sugar beet and xyloglucans in bamboo. It also can cross-link with proteins. Due to its phenolic nucleus and an extended side chain conjugation (carbohydrates and proteins), it readily forms a resonance stabilized phenoxy radical which accounts for its potent of the anti-oxidant potential (HMDB). The ferulic acid exists as the trans- and the cis- isomers, which interconverted by isomerization and are deprotonated to their anionic and the dianionic forms in aqueous solution, depending on the pH and the environment. Although the t-isomer predominates, both found in plants. The cis-trans isomer ratio in the cell walls of the corn, a rich source is 0.16. The ferulic acid features strong absorptions of UV-A (315–400 nm) and UV-B (280–315 nm). This feature enables ferulic acid to act as a natural sun-protectant (Wang et al. 2017). The levels of the ferulic acid dehydrodimers in the cereals range at 250–475 μg/g (Fig. 9.7). The ferulic acid widely found in fruits, vegetables, coffee, and beer. The ferulic acid protects against reactive nitrogen species and inhibits the toxicity of the secondary free radicals. While reacting against a free radical, the hydrogen atom of ferulic acid easily transferred to the radical, forming a phenoxy radical that is highly stabilized. Due to the generation of this phenoxy radical, the ferulic acid can scavenge and stop free radical chain reactions. The ferulic acid acts with a vital role as an anti-inflammatory agent in various pathophysiological conditions either by decreasing the pro-inflammatory cytokines (Ghosh et  al. 2017). The ferulic acid exerts some additional effect on autophagy that contributes to the cellular quality control by removing unfolded and denatured proteins. In addition to the known effects of ferulic acid against oxidative stress, the stimulatory effect on autophagy by ferulic acid may have additional functional implications in the cell-protective roles (Bian et al. 2012) (Fig. 9.8). Synaptic acid  is one of the important bioactive compounds in cereals and shows anti-oxidant, antimicrobial, anti-inflammatory, and anticancer activity. Mainly due to sinapic acid and its derivatives anti-oxidative activity, these compounds have suggested for potential use in food processing, cosmetics, and in the pharmaceutical industry (Boz 2014) (Figs. 9.9, 9.10, and 9.11).

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185

a

b

MW 651 Fig. 9.7  The ferulic acids, 100–1000 μg/g in the wheat kernel (Table 8.2). (a) trans-ferulic acid is a highly abundant phenolic phytochemical which presents in the plant cell walls. It absorbed by the small intestine and excreted in the urine. It is one of the most abundant phenolic acids in plants. It found as ester cross-links with the polysaccharides in the cell wall. Due to its phenolic nucleus and an extended side chain conjugation (carbohydrates and proteins), it readily forms a resonance stabilized phenoxy radical which accounts for its potent anti-oxidant potential (HMDB). (b) cis-­ ferulic acid consisting of cis-cinnamic acid bearing methoxy and hydroxy substituents at positions 3 and 4 respectively on the phenyl ring (HMDB). (c) cis-Ferulic acid [arabinosyl-(1->3)-[glucosyl(1->6)]-glucosyl] ester. (d) Diferulic acids (also known as dehydrodiferulic acids) are formed by dimerization of the ferulic acid and found in the cell wall of the plant (Wikipedia)

Syringic acid  It is a potent anti-oxidant used in traditional Chinese medicine. Hepatoprotective effects reported in animal models. Reported with anti-­ hyperglycaemic effects in rats at a high dose, reduction in pancreatic damage and enhanced β-cell regeneration. Some other health alleviative effects have counted such as anti-obesity, anti-inflammatory, and anti-steatotic, protective effects on the kidney in renal ischemia, anticancer effects of lung carcinoma. Syringic acid has also reported activity against various pathogens (Thipparaboina et  al. 2016) (Figs. 9.12 and 9.13).

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c

MW 651

b

MW 386

C20H18O8

Fig. 9.7 (continued)

The Tannins The cereals contain condensed tannins, whose primary function to protect the grains from molds and deterioration, though they are also responsible for the astringency of the grain. The tannins decrease the digestibility of the proteins, the carbohydrates,

The Tannins

187

MW 180 Fig. 9.8  The sinaptic acid, 32 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. Synaptic acid is a common constituent of plants and fruits. Sinapic acid has shown to exhibit anti-inflammatory function. Sinapic acid belongs to the family of hydroxycinnamic acid derivatives where the benzene ring hydroxylated (HMDB)

MW 164

Fig. 9.9  The coumaric acid, 19 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. cis-p-coumaric acid is found in coriander. Coumaric acid is a hydroxycinnamic acid, an organic compound that is a hydroxy derivative of cinnamic acid. There are three isomers namely o-coumaric acid, m-coumaric acid, and p-coumaric acid that differ by the position of the hydroxy substitution of the phenyl group. p-coumaric acid is the most abundant isomer of the 3 in nature. cis-p-coumaric acid belongs to the family of hydroxycinnamic acid derivatives. These are compounds containing a cinnamic acid derivative where the benzene ring is hydroxylated (HMDB)

and the minerals and also possess anti-carcinogenic, gastroprotective, anti-­ ulcerogenic and cholesterol-lowering properties (Kaur et al. 2014). The term ‘tannin’ has employed classically to designate the substances of vegetable origin capable of transforming the fresh hide into leather. The tannins are widespread in the plants and the food of plant origin, in particular in fruits, legume seeds, cereal grains and different beverages (wine, tea, cocoa, cider). They defined as water-­soluble phenolic compounds having molecular weights of 500–3000 Da and, besides giving the usual phenolic reactions, have special properties such as the ability to precipitate alkaloids, gelatin, and other proteins. These polyphenols contain a large number of

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MW 168

Fig. 9.10  The vanillic acid (18 μg/g in wheat kernel (Table 8.2) shown in two graphical presentations. Vanillic acid is a phenolic acid found in some forms of vanilla and many other plant extracts. The vanillic acid is a flavoring compound and scent agent that produces a pleasant, creamy odor. It is the intermediate product in the two-step bioconversion of the ferulic acid to vanillin. The vanillic acid, which is chlorogenic acid, is an oxidized form of vanillin. It is also an intermediate in the production of the vanillin from the ferulic acid (HMDB)

MW 198

Fig. 9.11  The syringic acid, 9–18 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. Syringic acid is a phenol present in some distilled alcoholic beverages. Syringic acid is a product of the gut metabolism of anthocyanins and other polyphenols that consumed fruits and alcoholic beverages. The syringic acid correlated with high anti-oxidant activity and inhibition of LDL oxidation (HMDB)

hydroxyl or other functional groups (1–2 per 100 Da), and therefore are capable of forming cross-linkages with the proteins and other the macromolecules (Fig. 9.14). This property is essential to explain their role in plant protection against the pathogens or to deter the herbivores from feeding on the tannin-rich plants (Santos-­Buelga and Scalbert 2000; Chung et al. 1998). There are two main groups of tannins (condensed tannins and hydrolyzable tannins), which are categorized on their fundamental

The Tannins

189

MW 180

Fig. 9.12  The caffeic acid, 1.3 μg/g in wheat kernel (Table 8.2), shown in two graphical presentations. Caffeic acid is a polyphenol present in normal human urine positively correlated to coffee consumption and influenced by the dietary intake of diverse types of food

MW148

Fig. 9.13  The cinnamic acid, shown in two graphical resentations. Cinnamic acid It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in several plants. It exists as both a cis and a trans isomer, although the latter is more common (HMDB)

subunits. Most of the dietary tannins are water-hydrolyzable. The tannins have drawn increased attention because of their health-promoting properties such as their antioxidant anti-arteriosclerotic, anti-carcinogenic, and anti-microbial properties. Incorporating dietary tannins into popular flour-based foods, such as bread, would improve the functional food market (Wang et al. 2015). Unlike the fruit and the vegetable where the polyphenol compounds have detected as a free fraction, the majority of the whole-wheat polyphenols compounds have detected as bounded compounds. The wheat polyphenols are mainly to sugar residues and most of them released in the colon and exerting there their antioxidant activity.

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Fig. 9.14  Tannins, total tannins content of 450 μg/g in the wheat kernel (Table 8.2). Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. The term tannin refers to the source of tannins used in tanning animal hides into leather; however, the term is widely applied to any large polyphenolic compound containing sufficient hydroxyls and other groups (such as carboxyls) to form strong complexes with the proteins and the other macromolecules. The tannins have molecular weights in the range of 500 – >3000. Tannins usually divided into hydrolyzable tannins and condensed tannins (proanthocyanidins). At the center of a hydrolyzable tannin molecule, there is a polyol carbohydrate (usually D-glucose). The hydroxyl groups of the carbohydrate partially or esterified with the phenolic groups such as gallic acid (in gallo-tannins) or ellagic acid (in ellagi-tannins). Hydrolyzable tannins hydrolyzed by the weak acids or the weak bases to produce carbohydrate and phenolic acids. The condensed tannins, also known as pro-anthocyanidins, are polymers of 2–50 (or more) flavonoid units that joined by the carboncarbon bonds, which are not susceptible to being cleaved by hydrolysis. While hydrolyzable tannins and most condensed tannins are water-soluble, some very large condensed tannins are insoluble (HMDB)

The Flavonoids The flavonoids are a type of polyphenol with the general structure of a 15-carbon skeleton, which consists of two phenyl rings and a heterocyclic ring. Some flavonoids have inhibitory activity against the organisms that cause the plant diseases. They contain a unique C6-C3-C6 (diphenyl propane structure) structure and found ubiquitously in foods of plant origin while >4000 have described so far, and categorized into flavanols, flavones, catechins, flavanones, anthocyanidins and isoflavonoids (Hu et  al. 2000). They are mostly present as glycosides in which phenolic hydrogen or hydrogens substituted for the sugar moiety.

The Interactions of the Wheat Anti-oxidants in the Gut

191

The intake by humans estimated at 25 mg/d. This value only covers five aglycones including quercetin and the total intake of flavonoids from the plant food may reach several hundred mg/d. This level is not low as compared with that of vitamin E or vitamin C. They recognized as having a potentially beneficial effect on disease prevention with an inverse relationship between the intake of the flavonoids and coronary heart disease. The anti-oxidant activity of the flavonoids has frequently mentioned in connection with their physiological function in  vivo because of the oxidative stress is known to participate in the initial process of atherosclerosis leading to the coronary heart disease. The flavonoids act as anti-oxidants by the scavenging reactive oxygen species (ROS) and/or chelating metal ion responsible for the generation of ROS. A kinetic study of the inhibitory effect of several flavonoids on lipid peroxidation in solution and liposomal membranes showed that the flavonoids act as interfacial anti-oxidants in the lipid/water biphasic system. The hydrophilic property of the flavonoids facilitates their localization at the interface of the lipid bilayers resulting in effective inhibition of the initial attack by the aqueous radicals. The in vivo function of the dietary flavonoids cannot estimate without the knowledge of their absorption and metabolic fate. Thus, much study has done on the absorption and metabolism of the flavonoids. The flavonoids normally accumulate in plants as O-glycosylated derivatives, but several species, including major cereal crops, predominantly synthesize flavone-C-glycosides, which are stable to hydrolysis and are biologically active both in plants and as the dietary components (Brazier-Hicks et al. 2009). The refined flour contains less than 30% of flavonoid content as that of the whole-kernel (Li et al. 2015) (Figs. 9.15, 9.16, and 9.17).

The Interactions of the Wheat Anti-oxidants in the Gut The phenolic compounds interact with several macro- and micro- nutrients and host proteins within the gastrointestinal tract. These interactions result in the delayed or the decreased in the nutrient digestion and absorption. The absorption and the pharmacokinetic depend on their size, molecular complexity, charge, the food matrix, and the presence of other phenolic compounds. Polyphenols–cholesterol interactions may decrease cholesterol absorption. The interactions can occur within the micelles where the cholesterol molecules direct the polyphenols toward the micelle membrane and the polyphenols decrease the cholesterol accumulation inside the micelles and its further enteric uptake. In addition to the diminishing cholesterol incorporation into the micelles, the polyphenols hinder the cholesterol absorption by decreasing its solubility. The polyphenols can also hinder the enterohepatic circulation of the steroids and thus, the polyphenols have compared to the hypocholesterolemic drugs. The proteins can form hydrogen bonds and the hydrophobic interactions with the polyphenols and can reach colloidal-­size aggregates. The anti-oxidant capacity is one of the most recognized characteristics of the polyphenols, but it also seems to be necessary to prevent the

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Fig. 9.15  Flavonoids, total flavonoids content is 470  μg/g in the wheat kernel (Table 8.2). Flavonoids are a group of plant metabolites thought to provide health benefits through cell signaling pathways and anti-oxidant effects. These molecules found in a variety of fruits and vegetables. Flavonoids are polyphenolic molecules containing 15 carbon atoms and are soluble in water (Wikipedia)

MW 306 Fig. 9.16  Pelargonidin is a type of anthoxyans, The total anthocyanins content is 150 μg/g in the wheat kernel (Table 8.2). Pelargonidin is an anthocyanin (one of six), with an anti-oxidant and produces a characteristic orange color

oxidation of the essential nutrients before their uptake in the upper gut. Not all the polyphenols–enzyme interactions will result in a marked inhibition of the enzyme activities because they may not bind to the active site. The polyphenols can inhibit the α-amylase, and this inhibition can delay the digestion of the carbohydrates and decrease the absorption. Because of the α-amylase-inhibiting properties of the polyphenols, their antidiabetic potential compared to the acarbose a commercially available medication that acts through the α-amylase inhibition. The flavonoids considered a glucose-lowering effect and without the negative side effects. The health benefits of the polyphenols that inhibit the α-amylase in the gastrointestinal tract related to a decrease in glucose absorption that in turn impact insulin secretion, potentially improving the glucose/insulin metabolism at the whole-organism level. The orally ingested polyphenols subjected to absorption, distribution, metabolism, and excretion, with the typical pharmacokinetic profiles such as the maximum concentration, time to reach maximum concentration, area under the plasma concentration curve, and the mean residence time. In cereals such as

The Lignans

193

MW 208 C15H12O

Fig. 9.17  Chalcone, shown in two graphical presentations. Chalcone as is the flavone fraction of the dietary items. Chalcone is an aromatic ketone and an enone that forms the central core for a variety of important biological compounds, which known collectively as chalcones or chalconoids. Benzylideneacetophenone is the parent member of the chalcone series. Chalcones and their derivatives demonstrate wide range of the biological activities such as anti- oxidant, -diabetic, -neoplastic, -hypertensive, -retroviral, -inflammatory, -parasitic, -histaminic, -malarial, -fungal, -obesity, -platelet, -tubercular, immunosuppressant, -arrhythmic, -gout, anxiolytic, -spasmodic, -nociceptive, hypolipidemic, -filarial, -angiogenic, -protozoal, -bacterial, -steroidal, and cardioprotective

corn, sorghum, and wheat, the majority of the polyphenols, >75%, are bound to the indigestible cell wall polysaccharides. The linkage of the ferulic acid to the xylans from the wheat results in the low bio-accessibility of this compound in the small intestine (Domínguez-Avila et al. 2017).

The Lignans The wheat phenolic compound was a matter of major importance when human has adopted wheat as the main staple food. Two main groups of such metabolites are accumulating in the cereal kernels: . The phenolic acids that comprise the ferulic acid as the main fraction. A B. Lignans with the dietary phenolics include phenolic acids, phenolic polymers (commonly known as tannins), and flavonoids. Lignin and lignans share monolignols as common precursors and both potentially involved in the plant defense against pathogens with the anti -oxidant, −feedant, −bacterial, and -fungal activities. The phenolic acids including ferulic, vanillic, and p-coumaric acids are the major anti-oxidants in wheat and significantly contribute to the overall anti-oxidant properties of wheat grain. The genotype, growing conditions and the interaction between the growing condition and the genotype altered the anti-oxidant properties of the wheat samples and their levels of beneficial components, including total phenolics, phenolic acids, carotenoids and tocopherols (Okarter et  al. 2010; Gogoi et  al. 2001; Moraes et  al. 2008; Hano et  al. 2006); Gasztonyi et al. 2011). The lignans related chemically to lignin that is the major aerial organic compound on our planet. While the lignin is a long polymer, the lignans are mainly

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a O

O

O

O O

HO

b

O H

H

O

O

O

H

O O O

c

H

O

H3C

OH

HO OH

CH3 O OH

Fig. 9.18  The plant lignans (Adlercreutz 2007; Peterson et al. 2010), The matairesinol shown in two graphical presentations. (a) Actigenin. (b) Hydroxymatairesinol. (c) Secoisolariciresinol. (d) Syringaresinol. (e) Matairesinol

dimmers. Besides the anti-oxidant compounds, mentioned above, plants contain a long list of phytoestrogen compounds with two main groups of isoflavonoids and lignans (Fig.  9.18). Except for the isoflavonoids, some of the flavonoids also defined as estrogens and classified as phytoestrogens. The phytoestrogen lignans have a humeral or anti-humeral activity and they act as anti-oxidants. The plant lignans are phenolic substances derived from the phenylalanine synthesize via dimerization of the substituted cinnamic alcohols. The lignans generally play a defensive role in the plant with anti -microbial, −fungal, −viral and -oxidant properties. They found in seed coats, stems, leaves, flowers, and other various plant parts with high variability between crop varieties and samples (Dinelli et al. 2007).

The Lignans

195

d

e

Fig. 9.18 (continued)

The lignans metabolized in the colon by the microbiota activity to form enterolactone and enterodiol (Fig. 9.19). These compounds called mammalian lignans or enterolignans and absorbed into the bloodstream with anti-carcinogenic activity. After released from the precursors, mammalian lignans undergo the enterohepatic circulation. They are absorbed from the colon, transported to the liver by the portal venous blood, and secreted in the bile similarly to other enterohepatic cycles such as the bile acids cycle. Each type of compounds has own constituents and its cycling rate in the enterohepatic cycle. Such compounds are abundant in the plasma and the urine of the subjects living in areas with low cancer incidence. Whole-wheat lignan content ranges

196 Fig. 9.19  The mammalian lignans (Peterson et al. 2010), shown in two graphical presentations. (a) Enterodiol is one of the most important lignan-type phytoestrogens identified in the serum, urine, bile, and seminal fluids of humans and animals. Phytoestrogens are a diverse group of compounds found in many edible plants that have, as their common denominator, a phenolic group that they share with estrogenic steroids. This phenolic group appears to play an important role in determining the estrogenic agonist/antagonistic properties of these compounds. Phytoestrogens have categorized according to their chemical structures as isoflavones and lignans. The enterodiol formed by bacteria in the intestinal tract from the plant lignans matairesinol and secoisolariciresinol, which exist in various whole-­ grain cereals. (b) Enterolactone

9  The Anti-oxidants

a

b

The Benzoxazinoids

197

at 6–37 μg/g (Tables 8.2). Some other foods contain much higher concentrations such as Chianti wine 20, rye 19, flaxseed 3400, sesame 1300, chickpeas 350 and peas 84 μg/g (Peterson et al. 2010; Liu et al. 2007). However, the wheat lignin has a much higher impact than other foods because in the Western Hemisphere, the majority of the human intake derived from whole-wheat cereals (Adlercreutz 2007) (Figs.  9.18 and 9.19). In the liver, the lignans conjugated to the glucuronic and sulfate by the activity of the hepatic UDP-glucuronosyl transferase or sulfotransferase enzymes. This facilitates their clearance into the urine and the bile. The presence of intestinal glucuronosyl transferase and sulfotransferase suggests that the conjugation may also take place in the intestinal wall during the lignan uptake. A part of the circulating lignans delivered into the kidney and excreted in the urine. Hence, urinary lignan level is an indicator of the lignan intake, metabolism, and availability in humans and animals. The lignan is not a uniform compound and limited information has collected for the lignan effect on the morbidity. As for the phenolic anti-oxidants in the wheat, the lignan analysis in foods is very difficult to perform because no single method gives optimal conditions for all main lignin forms, and several analytical methods needed. Each crop has a lignan distribution of some tens of different compounds but no information is available which lignan type has a higher anti-carcinogenic activity or which lignan type has a lower effect. The main information about the anti-­ carcinogenic effect is based on the epidemiological studies but some information acquired by animal experimentation (Smeds et  al. 2007; Adlercreutz 2007; Slavin 2000).

The Benzoxazinoids Benzoxazinoid is an organic compound containing benzene fused to an oxazine ring (a 6-membered aliphatic ring with 4 carbon atoms, 1 oxygen atom, and 1 nitrogen atom). The MW is 179–672 (HMDB). The benzoxazinoids are a group of potent natural compounds that have identified in the whole-grain wheat and the rye grains and the bakery products of these cereals. The first discovery of the benzoxazinoids in wheat is going back only to 2006. The content of the total benzoxazinoids (typically around 10–12 different compounds) is in the range of 5  mg/g dry matter but in the rye bread, the concentration is ~250 mg/g dry matter. The benzoxazinoids have mostly studied for their function as allelochemicals/bioherbicides in the cereal plants and found in corn, triticale, wheat, and rye, but not in sorghum or rice. The benzoxazinoids stored as glycosides, which enzymatically hydrolyzed in response to stress. The individual benzoxazinoids have ascribed a broad spectrum of pharmacological and health-promoting effects and some of them possess anti -microbial, −allergic, −inflammatory, −cancer and antidepressant properties, as well as the effects on the appetite and the body weight. The whole-grain wheat and the rye products are the main currently known sources of the

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benzoxazinoids in the diet, and due to their demonstrated bioactivities, they may contribute to the positive health effects associated with the whole-grain consumption. The food processing affects the content and the composition of the benzoxazinoids in the cereals, which makes it more difficult to elucidate the bioactivity of the individual compounds but on the other hand, makes it possible to optimize the content of the specific compounds in foods. The cereal benzoxazinoids divided into three classes based on their chemical structure: (a) Benzoxazolinones; (b) Lactams; (c) Hydroxamic acids. During food processing, the benzoxazinoids readily undergo structural changes. The benzoxazinoids occurred in the plasma 3 h after feeding but with a different composition than in the diet, indicating that they are absorbed and metabolized. The reduction of hydroxyamic acids and the metabolism of some of the benzoxazinoids and the direct absorption of some glucosides, such as lactams, are important processes in benzoxazinoid absorption and metabolism (Andersson et al. 2014). The benzoxazinoids known from the earlier findings in medicinal plants and the young cereal plants discovered to be present in the whole-grain products. Thus, the potential health-protecting effects of the benzoxazinoids as an ingredient in the bread and breakfast cereals have come into new focus (Adhikari et al. 2015). The benzoxazinoids are thought to exhibit a broad spectrum of pharmacological and health-­ protecting effects. Interestingly, the amounts of these compounds increase drastically upon the sprouting and hydrothermal processing of the grains before the bread making. Their fate and the biological effects determined by how and where they are absorbed, metabolized, transported, and excreted. The epidemiological studies have demonstrated broad pharmacological and health-protecting effects of benzoxazinoids, including anti- microbial,-allergic, −inflammatory, −cancer, and -depressant effects, along with the role in the improving the sexual functions, appetite suppression, and weight reduction. These bioactive dietary compounds are of significant interest in nutrition and pharmaceutics (Andersson et al. 2014) (Fig. 9.20).

The Alkylresorcinol Chemically, alkylresorcinols comprise 3,5-dihydroxy-5-n-alkylbenzenes homologs. Derivatives with the unsaturated and oxygenated side chains also exist. In the cereal kernel, they located exclusively in the outer layer (bran) of the grain. They are present in higher levels in the rye than in the wheat but with high variability between varieties and the growing conditions (Fig. 9.21). The higher levels also presented in the “primitive” wheat lines (Triticum monococcum, Triticum dicoccum, and spelt) than in the more advanced durum and lines of the bread wheat. Lower contents of alkylresorcinols were present in the barley varieties, and they were absent from the oats. In contrast, the oat contains a group of

The Alkylresorcinol

199

OH

N

O

O

OH

2,4-Dihydroxy-2H-1,4benzoxazine-3(4H)-one is a benzoxazinoid precursor of 2aminophenol sulfate. This metabolite found in the urine of individuals that have consumed whole grains. It is a particularly strong biomarker for the consumption of the whole-grain rye bread

Fig. 9.20  Samples of derivatives of the benzoxazinoids present in the wheat kernel, 2 on the upper panel and 10 on the middle panel. On the lower panel a typical metabolite present in the human urine. Content on the wheat kernel is 5 μg/g (Table 9.2) (Tanwir et al. 2013)

phenolic compounds that are not present in the other cereals, namely the avenanthramides. The unsaturated. alkylresorcinols homologs account for about 20% of the total alk(en)ylresorcinol content in the rye and  150 IU/d (Dolara et al. 2012). Some of the kernel types of the cereal crops might have a higher antioxidant capacity than that of the wheat kernel. However, the evidence base-data accumulated for the wheat is much more extensive and robust than that collected for any other crop. Even so, the available information for these compounds in the wheat kernel is still quite restricted. The regular intake of the whole-wheat bread that covers ~30% of the whole-daily energy intake might overweigh all the positive effects of anti-aging commercialized compounds.

 he Variability in the Phenolics Concentrations Between T the Wheat Cultivars The anti-oxidant potency of the wheat grain fractions is mainly associated with the aleurone layer that is the protein-rich outermost layer of the grain endosperm. The ferulic acid and the other phenolic compounds present in the grain, mostly bound to the indigestible cell wall material. The phenolic acids and the flavonoids concentrations highly varied between the wheat cultivars. Such high variation leaves a very wide opening for the further selection and the development of the wheat cultivars with the higher levels of the phenolic compounds. The climatic conditions have a small influence on the content of the analyzed phenolic compounds. Even the difference between the species Triticum aestivum or Triticum turgidum does not effect on the phenol content. With the evaluation of 19 cultivars, 2 species showed high variability with two to six fold gap between the minimal and the maximal level of all cultivars assayed (Table 9.3).

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Table 9.3  Phenolic acid variations in the wheat kernel

Feulic acida 8–5’di-ferulic acida 5–5’di-ferulic acida 8-O-4’di-ferulic acida 8–5’di-ferulic acid benzofuran forma Syringic acid p-coumaric acid p-hydroxybenzoic acid Vanillic acid Apigenin (flavonoid)a Total phenolicsb Free phenolicsb Conjugated phenolicsb Bound phenolicsb Resorcinolb Tocolsb

Av SD Min μg/g 924 237 439 8 3 3 14 6 5 21 7 9 15 6 6 26 11 11 19 5 10 13 3 8 5 2 2 264 56 190 μg/g DM winter varieties 170 5 30 140 200 26

Max

Max/Min

1450 17 26 34 27 52 29 20 10 365

3.3 5.2 4.9 3.7 4.3 4.8 2.9 2.6 5.9 1.9

900 35 290 900 750 82

5.3 7.0 9.7 6.4 3.8 3.2

Data that did not designate by references 1 and 2, collected from >210 peers reviewed publications (the references for the kernel composition listed in Appendix 1) a Hernández et al. (2011) b Ward et al. (2008)

References Adhikari KB, Tanwir F, Gregersen PL, Steffensen SK, Jensen BM, Poulsen LK, Nielsen CH, Høyer S, Borre M, Fomsgaard IS (2015) Benzoxazinoids: cereal phytochemicals with putative therapeutic and health-protecting properties. Mol Nutr Food Res 59:1324–1338. https://doi. org/10.1002/mnfr.201400717 Adlercreutz H (2007) Lignans and human health. Crit Rev Clin Lab Sci 44:483–525. https://doi. org/10.1080/10408360701612942 Adom KK, Liu RH (2002) Antioxidant activity of grains. J Agric Food Chem 50:6182–6187. https://doi.org/10.1021/jf0205099 Albini A, Tosetti F, Li VW, Noonan DM, Li WW (2012) Cancer prevention by targeting angiogenesis. Nat Rev Clin Oncol 9:498–509. https://doi.org/10.1038/nrclinonc.2012.120 Alisson-Silva F, Liu JZ, Diaz SL, Deng L, Gareau MG, Marchelletta R, Chen X, Nizet V, Varki N, Barrett KE, Varki A (2018) Human evolutionary loss of epithelial Neu5Gc expression and species-specific susceptibility to cholera. PLoS Pathog 14:e1007133. https://doi.org/10.1371/ journal.ppat.1007133 Andersson AAM, Dimberg L, Åman P, Landberg R (2014) Recent findings on certain bioactive components in whole-grain wheat and rye. J Cereal Sci 59:294–311. https://doi.org/10.1016/j. jcs.2014.01.003 Anson NM, Berg RVD, Havenaar R, Bast A, Haenen GRMM (2008) Ferulic acid from aleurone determines the antioxidant potency of wheat grain (Triticum aestivum L.). J Agric Food Chem 56:5589–5594. https://doi.org/10.1021/jf800445k

References

211

Atanasova-Penichon V, Barreau C, Richard-Forget F (2016) Antioxidant secondary metabolites in cereals: potential involvement in resistance to Fusarium and mycotoxin accumulation. Front Microbiol 7:566. https://doi.org/10.3389/fmicb.2016.00566 Azqueta A, Collins A (2016) Polyphenols and DNA damage: a mixed blessing. Nutrients 8:785. https://doi.org/10.3390/nu8120785 Barberousse H, Roiseux O, Robert C, Paquot M, Deroanne C, Blecker C (2008) Analytical methodologies for quantification of ferulic acid and its oligomers. J Sci Food Agric 88:1494–1511 Bian Z, Furuya N, Zheng D-M, Trejo JAO, Tada N, Ezaki J, Ueno T (2012) Ferulic acid induces mammalian target of rapamycin inactivation in cultured mammalian cells. Biol Pharm Bull 36:120–124. https://doi.org/10.1248/bpb.b12-00695 Biltoft-Jensen A, Damsgaard CT, Andersen EW, Ygil KH, Andersen R, Ege M, Christensen T, Thorsen A-V, Tetens I, Wu H, Landberg R (2016) Validation of reported whole-grain intake from a web-based dietary record against plasma alkylresorcinol concentrations in 8- to 11-year-olds participating in a randomized controlled trial. J Nutr 146:377–383. https://doi. org/10.3945/jn.115.222620 Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C (2007) Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. J Am Med Assoc 297:842–857. https://doi.org/10.1001/jama.297.8.842 Boz H (2014) Sinapic acid in cereals. GIDA 40:55–60. https://doi.org/10.15237/gida.GD14038 Brandolini A, Castoldi P, Plizzari L, Hidalgo A (2013) Phenolic acids composition, total polyphenols content and antioxidant activity of Triticum monococcum, Triticum turgidum and Triticum aestivum: a two-years evaluation. J Cereal Sci 58:123–131. https://doi.org/10.1016/j. jcs.2013.03.011 Brazier-Hicks M, Evans KM, Gershater MC, Puschmann H, Steel PG, Edwards R (2009) The C-glycosylation of flavonoids in cereals. J Biol Chem 284:17926–17934. https://doi. org/10.1074/jbc.M109.009258 Caverzan A, Casassola A, Brammer SP (2016) Antioxidant responses of wheat plants under stress. Genet Mol Biol 39:1–6. https://doi.org/10.1590/1678-4685-GMB-2015-0109 Chung KT, Wong TY, Wei CI, Huang YW, Lin Y (1998) Tannins and human health: a review. Crit Rev Food Sci Nutr 38:421–464. https://doi.org/10.1080/10408699891274273 Cohen-Zinder M, Weinberg Z, Leibovich H, Chen Y, Rosen M, Sagi G, Orlov A, Agmon R, Yishay M, Miron J, Shabtay A (2017) Ensiled moringa oleifera: an antioxidant-rich feed that improves dairy cattle performance. J Agric Sci 155:1174–1186. https://doi.org/10.1017/ S0021859617000387 Conti V, Izzo V, Corbi G, Russomanno G, Manzo V, De Lise F, Donato AD, Filippelli A (2016) Antioxidant supplementation in the treatment of aging-associated diseases. Front Pharmacol 7:24. https://doi.org/10.3389/fphar.2016.00024 Cooper-Driver GA, Bhattacharya M, Harborne JB (1998) Role of phenolics in plant evolution. Phytochemistry 49:1165–1174. https://doi.org/10.1016/S0031-9422(98)00054-5 Damsgaard CT, Biltoft-Jensen A, Tetens I, Michaelsen KF, Lind MV, Astrup A, Landberg R (2017) Whole-grain intake, reflected by dietary records and biomarkers, is inversely associated with circulating insulin and other cardiometabolic markers in 8- to 11-year-old children. J Nutr 147:816–824. https://doi.org/10.3945/jn.116.244624 Dinelli G, Marotti I, Bosi S, Benedettelli S, Ghiselli L, Cortacero-Ramírez S, Carrasco-Pancorbo A, Segura-Carretero A, Fernández-Gutiérrez A (2007) Lignan profile in seeds of modern and old Italian soft wheat (Triticum aestivum L.) cultivars as revealed by CE-MS analyses. Electrophoresis 28:4212–4219. https://doi.org/10.1002/elps.200700301 Dinelli G, Segura-Carretero A, Silvestro RD, Marotti I, Arráez-Román D, Benedettelli S, Ghiselli L, Fernadez-Gutierrez A (2011) Profiles of phenolic compounds in modern and old common wheat varieties determined by liquid chromatography coupled with time-of-flight mass spectrometry. J Chromat A 1218:7670–7681. https://doi.org/10.1016/j.chroma.2011.05.065 Dolara P, Bigagli E, Collins A (2012) Antioxidant vitamins and mineral supplementation, life span expansion and cancer incidence: a critical commentary. Eur J Nutr 51:769–781. https://doi. org/10.1007/s00394-012-0389-2

212

9  The Anti-oxidants

Domínguez-Avila JA, Wall-Medrano A, Velderrain-Rodríguez GR, Chen CYO, Salazar-López NJ, Robles-Sánchez M, González-Aguilar GA (2017) Gastrointestinal interactions, absorption, splanchnic metabolism and pharmacokinetics of orally ingested phenolic compounds. Food Funct 8:15–38. https://doi.org/10.1039/c6fo01475e Dror Y, Hopp M (2014) Hair for brain trade-off, a metabolic bypass for encephalization. Springerplus 3:562. http://www.springerplus.com/content/3/1/562 Dror Y, Giveon SM, Stern F (2018) The nadir range of the U-shaped curve chap 11. In: Malavolta M, Mocchegiani E (eds) Trace elements and minerals in health and longevity, Series Rattan SIS (Ed) healthy ageing and longevity, vol 8. Springer, Cham, pp 303–325. https://doi. org/10.1007/978-3-030-03742-0/ Dykes L (2007) Phenolic compounds in cereal grains and their health benefits. Cereal Foods World 52:105–111. https://doi.org/10.1094/cfw-52-3-0105 Dziki D, Rózyło R, Gawlik-Dziki U, Świeca M (2014) Current trends in the enhancement of antioxidant activity of wheat bread by the addition of plant materials rich in phenolic compounds. Tr Food Sci Technol 40:48–61. https://doi.org/10.1016/j.tifs.2014.07.010 Fardet A, Rock E, Rémésy C (2008) Is the in vitro antioxidant potential of whole-grain cereals and cereal products well reflected in vivo? J Cereal Sci 48:258–276. https://doi.org/10.1016/j. jcs.2008.01.002 FDA (2013) A food labeling guide: guidance for industry. www.fda.gov/FoodLabelingGuide Gasztonyi MN, Farkas RT, Berki M, Petróczi IM, Daood HG (2011) Content of phenols in wheat as affected by varietal and agricultural factors. J Food Compos Anal 24:785–789. https://doi. org/10.1016/j.jfca.2011.04.011 Gembeh SV, Brown RL, Grimm C, Cleveland TE (2001) Identification of chemical components of corn kernel pericarp wax associated with resistance to Aspergillus flavus infection and Aflatoxin production. J Agric Food Chem 49:4635–4641 Ghosh S, Basak P, Dutta S, Chowdhury S, Sil PC (2017) New insights into the ameliorative effects of ferulic acid in pathophysiological conditions. Food Chem Toxicol 103:41–55. https://doi. org/10.1016/j.fct.2017.02.028 Girard M, Bee G (2020) Invited review: tannins as a potential alternative to antibiotics to prevent coliform diarrhea in weaned pigs. Animal 14:95–107. https://doi.org/10.1017/ S1751731119002143 Gogoi R, Singh DV, Srivastava KD (2001) Phenols as a biochemical basis of resistance in wheat against karnal bunt. Plant Pathol 50:470–476. https://doi.org/10.1046/ j.1365-3059.2001.00583.x Grattan BJ (2013) Plant sterols as anticancer nutrients: evidence for their role in breast cancer. Nutrients 5:359–387. https://doi.org/10.3390/nu5020359 Han HM, Koh BK (2011) Antioxidant activity of hard wheat flour, dough and bread prepared using various processes with the addition of different phenolic acids. J Sci Food Agric 91:604–608. https://doi.org/10.1002/jsfa.4188 Hano C, Addi M, Bensaddek L, Crônier D, Baltora-Rosset S, Doussot J, Maury S, Mesnard F, Chabbert B, Hawkins S, Lainé E, Lamblin F (2006) Differential accumulation of monolignol-­ derived compounds in elicited flax (Linum usitatissimum) cell suspension cultures. Planta 223:975–989. https://doi.org/10.1007/s00425-005-0156-1 Heiniö RL, Liukkonen KH, Myllymäki O, Pihlava JM, Adlercreutz H, Heinonen SM, Poutanen K (2008) Quantities of phenolic compounds and their impacts on the perceived flavour attributes of rye grain. J Cereal Sci 47:566–575. https://doi.org/10.1016/j.jcs.2007.06.018 Hejtmánková K, Lachman J, Hejtmánková A, Pivec V, Janovská D (2010) Tocols of selected spring wheat (Triticum aestivum L.), einkorn wheat (Triticum monococcum L.) and wild emmer (Triticum dicoccum Schuebl [Schrank]) varieties. Food Chem 123:1267–1274. https://doi. org/10.1016/j.foodchem.2010.05.064 Hernández L, Afonso D, Rodríguez EM, Díaz C (2011) Phenolic compounds in wheat grain cultivars. Plant Foods Hum Nutr 66:408–415. https://doi.org/10.1007/s11130-011-0261-1 HMDB. : http://www.hmdb.ca/hml

References

213

Hu HL, Forsey RJ, Blades TJ, Barratt MEJ, Parmar P, Powell JR (2000) Antioxidants may contribute in the fight against ageing: an in vitro model. Mech Ageing Dev 121:217–230. https://doi. org/10.1016/S0047-6374(00)00212-8 Kaur KD, Jha A, Sabikhi L, Singh AK (2014) Significance of coarse cereals in health and nutrition: a review. J Food Sci Technol 51:1429–1441. https://doi.org/10.1007/s13197-011-0612-9 Kaur H, Salh PK, Singh B (2017) Role of defense enzymes and phenolics in resistance of wheat crop (Triticum aestivum L.) towards aphid complex. J Plant Interact 12:304–311. https://doi. org/10.1080/17429145.2017.1353653 Kyro C, Olsen A, Bueno-De-Mesquita HB, Skeie G, Loft S, Åman P, Leenders M, Dik VK, Siersema PD, Pischon T, Christensen J, Overvad K, Boutron-Ruault MC, Fagherazzi G, Cottet V, Kühn T, Chang-Claude J, Boeing H, Trichopoulou A, Naska A, Oikonomidou D, Masala G, Pala V, Tumino R, Vineis P, Mattiello A, Peeters PH, Bakken T, Weiderpass E, Åsli LA, Sánchez S, Jakszyn P, Sánchez MJ, Amiano P, Huerta JM, Barricarte A, Ljuslinder I, Palmqvist R, Khaw KT, Wareham N, Key TJ, Travis RC, Slimani N, Freisling H, Ferrari P, Gunter MJ, Murphy N, Riboli E, Tjonneland A, Landberg R (2014) Plasma alkylresorcinol concentrations, biomarkers of whole-grain wheat and rye intake, in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Br J Nutr 111:1881–1890. https://doi.org/10.1017/ S0007114513004388 Kyrø C, Olsen A, Landberg R, Skeie G, Loft S, Åman P, Leenders M, Dik VK, Siersema PD, Pischon T, Christensen J, Overvad K, Boutron-Ruault MC, Fagherazzi G, Cottet V, Kühn T, Chang-Claude J, Boeing H, Trichopoulou A, Bamia C, Trichopoulos D, Palli D, Krogh V, Tumino R, Vineis P, Panico S, Peeters PH, Weiderpass E, Bakken T, Åsli LA, Argüelles M, Jakszyn P, Sánchez MJ, Amiano P, Huerta JM, Barricarte A, Ljuslinder I, Palmqvist R, Khaw KT, Wareham N, Key TJ, Travis RC, Ferrari P, Freisling H, Jenab M, Gunter MJ, Murphy N, Riboli E, Tjønneland A, Bueno-De-Mesquita HB (2014) Plasma alkylresorcinols, biomarkers of whole-grain wheat and rye intake, and incidence of colorectal cancer. J Natl Cancer Inst 106:djt352. https://doi.org/10.1093/jnci/djt352 Landberg R, Kamal-Eldin A, Andersson A, Vessby B, Åman P (2008) Alkylresorcinols as biomarkers of whole-grain wheat and rye intake: plasma concentration and intake estimated from dietary records. Am J Clin Nutr 87:832–838 Landberg R, Andersson AAM, Åman P, Kamal-Eldin A (2009) Comparison of GC and colorimetry for the determination of alkylresorcinol homologues in cereal grains and products. Food Chem 113:1363–1369. https://doi.org/10.1016/j.foodchem.2008.08.072 Landberg R, Åman P, Hallmans G, Johansson I (2013) Long-term reproducibility of plasma alkylresorcinols as biomarkers of whole-grain wheat and rye intake within Northern Sweden Health and Disease Study Cohort. Eur J Clin Nutr 67:259–263. https://doi.org/10.1038/ejcn.2013.10 Landberg R, Marklund M, Kamal-Eldin A, Åman P (2014) An update on alkylresorcinols - occurrence, bioavailability, bioactivity and utility as biomarkers. J Funct Foods 7:77–89. https://doi. org/10.1016/j.jff.2013.09.004 Li L, Shewry PR, Ward JL (2008) Phenolic acids in wheat varieties in the HEALTH GRAIN Diversity Screen. J Agric Food Chem 56:9732–9739 Li Y, Ma D, Sun D, Wang C, Zhang J, Xie Y, Guo T (2015) Total phenolic, flavonoid content, and antioxidant activity of flour, noodles, and steamed bread made from different colored wheat grains by three milling methods. Crop J 3:328–334. https://doi.org/10.1016/j.cj.2015.04.004 Liu RH (2007) Whole-grain phytochemicals and health. J Cereal Sci 46:207–219. https://doi. org/10.1016/j.jcs.2007.06.010 Ma J, Ross AB, Shea MK, Bruce SJ, Jacques PF, Saltzman E, Lichtenstein AH, Booth SL, McKeown NM (2012) Plasma alkylresorcinols, biomarkers of whole-grain intake, are related to lower BMI in older adults. J Nutr 142:1859–1864. https://doi.org/10.3945/jn.112.163253 Ma D, Li Y, Zhang J, Wang C, Qin H, Ding H, Xie Y, Guo T (2016) Accumulation of phenolic compounds and expression profiles of phenolic acid biosynthesis-related genes in developing grains of white, purple, and red wheat. Front Plant Sci 7:528. https://doi.org/10.3389/fpls.2016.00528

214

9  The Anti-oxidants

Magnusdottir OK, Landberg R, Gunnarsdottir I, Cloetens L, Akesson B, Landin-Olsson M, Rosqvist F, Iggman D, Schwab U, Herzig KH, Savolainen MJ, Brader L, Hermansen K, Kolehmainen M, Poutanen K, Uusitupa M, Thorsdottir I, Risérus U (2014) Plasma alkylresorcinols C17:0/C21:0 ratio, a biomarker of relative whole-grain rye intake, is associated to insulin sensitivity: a randomized study. Eur J Clin Nutr 68:453–458. https://doi.org/10.1038/ ejcn.2014.12 Manach C, Scalbert A, Morand C, Rémésy C, Jiménez L (2004) Polyphenols: food sources and bioavailability. Am J Clin Nutr 79:727–747 Martínez-Tomé M, Murcia MA, Frega N, Ruggieri S, Jiménez AM, Roses F, Parras P (2004) Evaluation of antioxidant capacity of cereal brans. J Agric Food Chem 52:4690–4699. https:// doi.org/10.1021/jf049621s McKeown NM, Hruby A, Landberg R, Herrington DM, Lichtenstein AH (2016a) Plasma alkylresorcinols, biomarkers of whole-grain intake, are not associated with progression of coronary artery atherosclerosis in postmenopausal women with coronary artery disease. Public Health Nutr 19:326–331. https://doi.org/10.1017/S1368980015001123 McKeown NM, Marklund M, Ma J, Ross AB, Lichtenstein AH, Livingston KA, Jacques PF, Rasmussen HM, Blumberg JB, Chen CYO (2016b) Comparison of plasma alkylresorcinols (AR) and urinary AR metabolites as biomarkers of compliance in a short-term, whole-grain intervention study. Eur J Nutr 55:1235–1244. https://doi.org/10.1007/s00394-015-0936-8 Moraes MCB, Birkett MA, Gordon-Weeks R, Smart LE, Martin JL, Pye BJ, Bromilow R, Pickett JA (2008) cis-Jasmone induces accumulation of defence compounds in wheat, Triticum aestivum. Phytochemistry 69:9–17. https://doi.org/10.1016/j.phytochem.2007.06.020 Moura FFD, Lewis KD, Falk MC (2009) Applying the FDA definition of whole-grains to the evidence for cardiovascular disease health claims. J Nutr 139:2220S–2226S. https://doi. org/10.3945/jn.109.112383 Naito-Matsui Y, Davies LRL, Takematsu H, Chou HH, Tangvoranuntakul P, Carlin AF, Verhagen A, Heyser CJ, Yoo SW, Choudhury B, Paton JC, Paton AW, Varki NM, Schnaar RL, Varki A (2017) Physiological exploration of the long term evolutionary selection against expression of N-glycolylneuraminic acid in the brain. J Biol Chem 292:2557–2570. https://doi.org/10.1074/ jbc.M116.768531 Nikolić N, Stojanović J, Mitrović J, Lazić M, Karabegović I, Stojanović G (2016) The antioxidant activity and the composition of free and bound phenolic acids in dough of wheat flour enriched by boletus edulis after mixing and thermal processing. Int J Food Sci Technol 51:2019–2025. https://doi.org/10.1111/ijfs.13172 Nyström L, Lampi AM, Rita H, Aura AM, Oksman-Caldentey KM, Piironen V (2007) Effects of processing on availability of total plant sterols, steryl ferulates and steryl glycosides from wheat and rye bran. J Agric Food Chem 55:9059–9065. https://doi.org/10.1021/jf071579o Okarter N, Liu CS, Sorrells ME, Liu RH (2010) Phytochemical content and antioxidant activity of six diverse varieties of whole-wheat. Food Chem 119:249–257. https://doi.org/10.1016/j. foodchem.2009.06.021 Pasha I, Saqib I, Butt MS, Randhawa MA, Saeed F, Waqas K (2014) Distribution of phenolic acids in milling fractions of spring wheats. Int J Food Prop 17:2052–2062. https://doi.org/10.1080/ 10942912.2011.570470 Pérez-Jiménez J, Neveu V, Vos F, Scalbert A (2010) Systematic analysis of the content of 502 polyphenols in 452 foods and beverages: an application of the phenol-explorer database. J Agric Food Chem 58:4959–4969. https://doi.org/10.1021/jf100128b Peterson J, Dwyer J, Adlercreutz H, Scalbert A, Jacques P, McCullough ML (2010) dietary lignans: physiology and potential for cardiovascular disease risk reduction. Nutr Rev 68:571–603. https://doi.org/10.1111/j.1753-4887.2010.00319.x Phillips KM, Ruggio DM, Ashraf-Khorassani M (2005) Phytosterol composition of nuts and seeds commonly consumed in the United States. J Agric Food Chem 53:9436–9445. https://doi. org/10.1021/jf051505h Pisoschi AM, Pop A (2015) The role of antioxidants in the chemistry of oxidative stress: a review. Eur J Med Chem 97:55–74. https://doi.org/10.1016/j.ejmech.2015.04.040

References

215

Quideau S, Deffieux D, Douat-Casassus C, Pouységu L (2011) Plant polyphenols: chemical properties, biological activities, and synthesis. Angew Chemie Int Ed 50:586–621. https://doi. org/10.1002/anie.201000044 Radchuk V, Borisjuk L (2014) Physical, metabolic and developmental functions of the seed coat. Front Plant Sci 5:510. https://doi.org/10.3389/fpls.2014.00510 Rajendran P, Nandakumar N, Rengarajan T, Palaniswami R, Gnanadhas EN, Lakshminarasaiah U, Gopas J, Nishigaki I (2014) Antioxidants and human diseases. Clin Chim Acta 436:332–347. https://doi.org/10.1016/j.cca.2014.06.004 Rosa-Sibakov N, Poutanen K, Micard V (2015) How does wheat grain, bran and aleurone structure impact their nutritional and technological properties? Tr Food Sci Technol 41:118–134. https:// doi.org/10.1016/j.tifs.2014.10.003 Ross AB (2012) Present status and perspectives on the use of alkylresorcinols as biomarkers of wholegrain wheat and rye intake. J Nutr Metab 2012:462967. https://doi.org/ 10.1155/2012/462967 Ross AB, Shepherd MJ, Schüpphaus M, Sinclair V, Alfaro B, Kamal-Eldin A, Åman P (2003) Alkylresorcinols in cereals and cereal products. J Agric Food Chem 51:4111–4118. https://doi. org/10.1021/jf0340456 Ross AB, Kamal-Eldin A, Aman P (2004) dietary alkylresorcinols: absorption, bioactivities, and possible use as biomarkers of whole-grain wheat– and rye–rich foods. Nutr Rev 62:81–95. https://doi.org/10.1301/nr.2004.mar.81 Ross AB, Bourgeois A, Macharia HN, Kochhar S, Jebb SA, Brownlee IA, Seal CJ (2012) Plasma alkylresorcinols as a biomarker of whole-grain food consumption in a large population: results from the WHOL Eheart Intervention Study. Am J Clin Nutr 95:204–211. https://doi. org/10.3945/ajcn.110.008508.204 Ross AB, Kristensen M, Seal CJ, Jacques P, McKeown NM (2015a) Recommendations for reporting whole-grain intake in observational and intervention studies. Am J Clin Nutr 101:903–907. https://doi.org/10.3945/ajcn.114.098046 Ross AB, Colega MT, Lim AL, Silva-Zolezzi I, Macé K, Saw SM, Kwek K, Gluckman P, Godfrey KM, Chong YS, Chong MFF (2015b) Whole-grain intake, determined by dietary records and plasma alkylresorcinol concentrations, is low among pregnant women in Singapore. Asia Pac J Clin Nutr 24:674–682. https://doi.org/10.6133/apjcn.2015.24.4.19 Santos-Buelga C, Scalbert A (2000) Proanthocyanidins and tannin-like compounds  – nature, occurrence, dietary intake and effects on nutrition and health. J Sci Food Agric 80:1094–1117. https://doi.org/10.1002/(SICI)1097-0010(20000515)80:73.0.CO;2-1 Seifried HE, Anderson DE, Fisher EI, Milner JA (2007) A review of the interaction among dietary antioxidants and reactive oxygen species. J Nutr Biochem 18:567–579. https://doi. org/10.1016/j.jnutbio.2006.10.007 Sharma M, Sandhir R, Singh A, Kumar P, Mishra A, Jachak S, Singh SP, Singh J, Roy J (2016) Comparative analysis of phenolic compound characterization and their biosynthesis genes between two diverse bread wheat (Triticum aestivum) varieties differing for chapatti (unleavened flat bread) quality. Front Plant Sci 7:1870. https://doi.org/10.3389/fpls.2016.01870 Slavin JL (2000) Mechanisms for the impact of whole-grain foods on cancer risk. J Am Coll Nutr 19:300S–307S. https://doi.org/10.1080/07315724.2000.10718964 Smeds AI, Eklund PC, Sjöholm RE, Willför SM, Nishibe S, Deyama T, Holmbom BR (2007) Quantification of a broad spectrum of lignans in cereals, oilseeds, and nuts. J Agric Food Chem 55:1337–1346. https://doi.org/10.1021/jf0629134 Sun T, Rong Y, Hu X, Zhu Y, Huang H, Chen L, Li P, Li S, Yang W, Cheng J, Yang X, Yao P, Hu FB, Liu L (2018) Plasma alkylresorcinol metabolite, a biomarker of whole- grain wheat and rye intake, and risk of type 2 diabetes and impaired glucose regulation in a Chinese population. Diabetes Care 41:440–445. https://doi.org/10.2337/dc17-1570 Tanwir F, Fredholm M, Gregersen PL, Fomsgaard IS (2013) Comparison of the levels of bioactive benzoxazinoids in different wheat and rye fractions and the transformation of these compounds in homemade foods. Food Chem 141:444–450. https://doi.org/10.1016/j. foodchem.2013.02.109

216

9  The Anti-oxidants

Thipparaboina R, Mittapalli S, Thatikonda S, Nangia A, Naidu VGM, Shastri NR (2016) Syringica acid: structural elucidation and co-crystallization. Cryst Growth Des 16:4679–4687. https:// doi.org/10.1021/acs.cgd.6b00750 Varki A (2007) Glycan-based interactions involving vertebrate sialic-acid-recognizing proteins. Nature 446:1023–1029. https://doi.org/10.1038/nature05816 Vitaglione P, Napolitano A, Fogliano V (2008) Cereal dietary fibre: a natural functional ingredient to deliver phenolic compounds into the gut. Tr Food Sci Technol 19:451–463. https://doi. org/10.1016/j.tifs.2008.02.005 Wang Q, Li Y, Sun F, Li X, Wang P, Sun J, Zeng J, Wang C, Hu W, Chang J, Chen M, Wang Y, Li K, Yang G, He G (2015) Tannins improve dough mixing properties through affecting physicochemical and structural properties of wheat gluten proteins. Food Res Int 69:64–71. https://doi. org/10.1016/j.foodres.2014.12.012 Wang S, Schatz S, Stuhldreier MC, Böhnke H, Wiese J, Schröder C, Raeker T, Hartke B, Keppler JK, Schwarz K, Renth F, Temps F (2017) Ultrafast dynamics of UV-excited: trans  – and cis – ferulic acid in aqueous solutions. Phys Chem Chem Phys 19:30683–30694. https://doi. org/10.1039/c7cp05301k Ward JL, Poutanen K, Gebruers K, Piironen V, Lampi AM, Nyström L, Andersson AAM, Åman P, Boros D, Rakszegi M, Bedo Z, Shewry PR (2008) The HEALTHGRAIN cereal diversity screen: concept, results, and prospects. J Agric Food Chem 56:9699–9709. https://doi. org/10.1021/jf8009574 Wikipedia. : https://www.wikipedia.org/ Zawistowski J, Jones P (2015) Regulatory aspects related to plant sterol and stanol supplemented foods. J AOAC Int 98:750–756. https://doi.org/10.5740/jaoacint.SGEZawistowski Zhao Z, Moghadasian MH (2008) Chemistry, natural sources, dietary intake and pharmacokinetic properties of ferulic acid: a review. Food Chem 109:691–702. https://doi.org/10.1016/j. foodchem.2008.02.039 Zhu F (2015) Interactions between starch and phenolic compound. Tr Food Sci Technol 43:129– 143. https://doi.org/10.1016/j.tifs.2015.02.003

Chapter 10

The Anti-oxidant Capacity

Measuring of the Anti-oxidant Capacity The anti-oxidant capacity is widely used as a parameter to characterize different substances and food samples with the ability to scavenge or neutralize free radicals. This capacity related to the presence of compounds capable of protecting a biological system against harmful oxidation. There are several methods for the evaluation of anti-oxidant efficiency of pure compounds and plant extracts such as ORAC (oxygen radical absorbance capacity), FRAP (ferric reducing anti-oxidant power), CUPRAC (cupric reducing anti-oxidant capacity), the 2,2-azino bis(3-ethyl-­ benzothiazoline-­6-sulphonate) radical cation (ABTS) assay and the 2,2-diphenyl-­1picrylhydrazyl radical (DPPH) assay. Each of these assays has limitations, with difficulties to compare directly because they differ from each other in terms of substrates, probes, and quantitation methods. Even within the same assay, the lack of standard procedures makes it difficult to compare data from lab to lab. So far, no single assay accurately reflects them all. The complexity of chemistry of anti-oxidant assays and inconsistent procedures have created considerable disorder and controversy in anti-oxidant reporting. Without standardization of analytical methods, reliable measures of rates, extent, and conditions for radical quenching by natural compounds of different structures cannot be provided for the foods. The DPPH free radical scavenging method offers the first approach for evaluating the anti-oxidant potential of a compound, an extract or other biological sources. This is the simplest method, wherein the prospective compound or extract is mixed with DPPH solution and absorbance is recorded after a defined period. This reaction can be easily followed by common spectrophotometric detection. The DPPH (2,2-diphenylpicrylhydrazyl) assay is one of the most popular and frequently employed methods to test the ability of compounds to act as free radical scavengers or hydrogen donors the and to evaluate the anti-oxidant capacity of foods (Pyrzynska and Pȩkal 2013). © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_10

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The DPPH assay is considered as an easy and useful spectrophotometric the method with regards to screening or measuring the anti-oxidant activity of extracts of food samples. It can be used for solid and liquid samples. The DPPH radical is stable, commercially available, and does not have to be generated before assay. It is not specific to any particular anti-oxidant component but applies to the overall anti-­ oxidant capacity of the sample. The main problem is the compatibility of the obtained values between several laboratories due to different reaction times, solvents, pH and different anti-oxidant standard compounds, which are frequently applied. The DPPH assay should be validated and standardized with a large body of comparable data available in the literature. The trolox activity could be used as the baseline unit of measurement to allow comparison between different studies as well as between different methods used for evaluation of the anti-oxidant activity in food, beverages, food ingredients and dietary supplements (Pyrzynska and Pȩkal 2013; Kedare and Singh 2011; Tian and Schaich 2013). Because of the total antioxidant capacity comprises a pilar virtue of the whole-­ bread quality, the definition and the quantification of such a quality is crucial for the nutritional evaluation of the whole-bread. Presently, no standard and accepted method for the determination of the total antioxidant capacity in bread has notified. A major difficulty in establishing a consensual method for the total antioxidant capacity is the adjustment of the standard of the chemical methods for the wide variability of food items. For the dietary evaluation of the antioxidant content in our menu, a chemical method for the detection of the total antioxidant capacity in the wheat kernel and the whole-wheat bread should develop without considering the suitability of the chemical method for the other food items.

The Enzymatic Inhibition of the Yeast Activity The aggressive activities of the water decomposition by the light in the plant chloroplast require a robust defense system against the reactive oxygen species (ROS) to protect the delicate membranes and their embedded enzymes, the transporters and the other proteins with the biological activities. The plant produces tens and hundreds of the anti-oxidant molecules to protect its delicate system from the destructive activity of the reactive oxygen species. The plant also stores and uses these compounds to protect its most delicate organ of reproduction namely the embryos and the surrounding tissues of the grains and similar organs to ensure higher storability of the grain. The seed constitutes the main vector of the plant propagation and it is a critical development stage with many specificities. Seed longevity is a major challenge for the conservation of plant biodiversity and crop success. The seeds possess a wide range of systems (protection, detoxification, and repair)

The Enzymatic Inhibition of the Yeast Activity

219

a­ llowing them to survive in the dry state and to preserve a high germination ability (Rajjou and Debeaujon 2008). The wheat kernel contains many anti-oxidants (Tables 8.2, 8.6, 9.2, and 10.1) with various types of activities that enable the grain storability. Generally, the higher anti-oxidants content enables longer survival periods within years to ensure the successive germination. After digested by the gut, the anti-oxidant compounds protect the delicate membranes of the animal against the destructive activities of the oxygen reactive species that produced at higher amounts by the inner mitochondrial membrane. When human has bred the grains, he adjusted the concentrations of the specific anti-­ oxidant compounds, presumably unknowingly, for his needs. Since the beginning of the industrial revolution, when the majority of the wheat flour refined for a “pure” and “white” bread, a drastic reduction observed in the “dirty” yellow pigments for the production of whiter flour. The polyphenols of the various types of exert inhibitory activity on the kernel glycosidases and amylases (Kong et  al. 2016; Kandil et al. 2012; Hanhineva et al. 2010). Each compound has a distinct inhibitory activity against the yeast fermentation (Jeong et al. 2012). All of these polyphenols inhibiting the key enzymes that enable the baker’s yeasts to decompose the starch in the exerting dough rising. Since the whole-wheat contains much higher polyphenols content and other anti-­ oxidants than the kernel endosperm, the dough rising prepared from the whole-­ wheat flour inferior that of the dough produced from white refined flour. The breaking out of the gas bubbles by the bran delicate fibers occasionally counted as the main cause of the retardation in the dough rising that produced by the yeast activity. Because of both effects, the content of the fiber particles and the content of the polyphenols are highly correlated, no distinction can make between the effects of these 2 effects. However, the specific knowledge about the distinct inhibitory activity of the various phenols present in the wheat kernel and the various amylases and the glycosidases present in the yeast baker’s enables the isolation of the specific yeast strains for the efficient dough rising and develop an efficient methodology for the baking of the whole-wheat bread. The developing of specific yeast strains is Table 10.1  The daily polyphenol intake in the Israeli menu (Statistical Abstract of Israel 2016) Main food group/item mg/d Oats 70 Potato 36 Pulses 23 Oilseeds 90 Vegetables 230 Fruits 450 Wine 2 Total excludes wheat products 900 Whole-wheat products The total polyphenol content includes the whole-wheat ingredients

900 1800

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most important for the success of the production of the improved whole-wheat bread with the expected higher contents of anti-oxidants. When human has practiced the dough rising he presumably preferred lower concentrations of the polyphenols to ensure the effective dough rising. The wild wheat types needed higher polyphenols content of the wheat kernel to ensure longer storability period that enables germination of the seed after a long period of remaining in the soil. Thus, besides depletion of the yellow pigments, the wheat kernel has also depleted the polyphenols content. The alleviative effect of whole-wheat bread on diabetes type 2 might partially explain by the inhibition of glycosidases activity by the polyphenols.

The Anti-oxidants Destruction Food-processing procedures recognized as one of the major factors on the destruction or changes of the natural phytochemicals, which may affect the anti-oxidant capacity in foods. The destruction of the phenolic compounds primarily caused by the oxidation, the cleavage of the covalent bonds, or the enhanced oxidation reactions due to the thermal processing. The chemical or the enzymatic oxidations have widely proven to cause a progressive decrease in the polyphenol anti-oxidant properties. The processing or the prolonged storage time can promote or enhance the rate of the oxidation of the phenolic compounds depending on the intrinsic properties of the food matrix. During the thermal processing of the food, the phytochemicals such as phenolic acid and the flavonoids degrade/modify their structural form. The polyphenols present in the grains in the free and the bound states with different vulnerability to the destructive effects. As the treatment of the thermal processing progresses, the naturally occurring anti-oxidants degrade and the new compounds with the potential anti-oxidant activity released. The polyphenolic compounds include anthocyanins and pro-anthocyanidins are not completely stable during heat processing. The physical and the biological factors, such as the increase the enzymatic activity may destroy the phenolic anti-oxidants such as the phenolic acids and the anthocyanins and may reduce the related bioactivity. During baking, the outer layer of the food item usually heated to >120 °C while the inner temperature remains at 95% of the total feruloyl groups present in the released wheat fiber (Nayak et al. 2015). The total anti-oxidant capacity is presumably the most significant ingredient that affects the final nutritional quality of the bread (that affects the health status) while the variability of such ingredients between cultivars, growing conditions, the storage conditions, and storage duration is the highest. Hence, a consensual and ready-­ to-­use methodology for the evaluation and labeling of the total anti-oxidant capacity crucially required for all intermediate bread products such as: (a) (b) (c) (d)

Crude grain. Flour. Dough. Bread.

The wheat classification follows the market demands, classified as the spring or the winter wheat harvests, the soft or the hard kernel texture, and the red or the white grain color, the protein content, and the baking quality. The wheat does not classify according to its phenolic content or its anti-oxidant capacity. Presently, the cereal industry prefers the white wheat for the darker colored cultivars. The grain color used to segregate between the red and the white wheat. In terms of the consumption in the US, the hard red winter wheat dominates the market, followed by (in decreasing order of use) the soft red, the hard red spring, the white, and the durum while the dealers of the wheat marketing looking very carefully for the wheat qualities. Traditionally, the wheat cultivars have mainly bred for the quality of the agronomic characteristics such as the yield, the pathogen resistance, and the gluten quantity and quality. The bread wheat has not yet bred for the high phenolic content and the anti-oxidant capacity.

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The Human Blood Anti-oxidants To neutralize the reactive oxygen species the living organisms developed the anti-­oxidant systems. The 1st line of the defense is the enzymatic anti-oxidant system, which neutralizes the action of the O2-with the superoxide dismutase and of the H2O2 with the catalase and the glutathione peroxidase/glutathione reductase system. The 2nd line of the defense constituted mainly by the protein reduced thiols and the low-molecular-weight anti-oxidants. The low-molecular-weight anti-­ oxidants comprise a wide variety of molecules, including the dietary ingredients (tocopherols, ascorbate, retinol, polyphenols, and more) and the metabolic products (urate, ascorbate, and reduced glutathione). These compounds comprise a significant part of the anti-oxidant capacity of the tissues and the biological fluids. Some of these compounds can penetrate the cells and achieve specific locations where the oxidative attack may occur (Tessutti et al. 2013). Unfortunately, the direct relationship between the blood polyphenol derived from the wheat kernel concentrations and morbidity has not presented, but such a relationship between the lignan (polyphenols) compounds have presented. In a Finish study, the significant association was shown between the elevated serum enterolactone (a lignan compound) and the reduced risk of coronary vascular disease- and coronary vascular disease-related mortality (coronary hurt/vascular disease). The risk of coronary vascular disease- and coronary vascular disease-­ related death decreased linearly across the quartiles of the serum enterolactone. Additionally, significant differences observed in the blood pressure and hypertension prevalence with a decrease from the 1st quintile of serum enterolactone. In a multivariate model, the relative risk of all-cause mortality for the 2nd, 3rd, and the 4th quintiles (in comparison to the 1st) were 1.07, 0.85 and 0.76 respectively (p 0.5 of those who are diagnosed will have another within 5–10 y. The high prevalence and recurrent and u­ npredictable nature of stone disease contribute to the substantial impact on the individual, healthcare systems, and society (Morgan and Pearle 2016). The calcium oxalate constituents of ~75% of all urinary stones. The hyperoxaluria is a primary risk factor in the development of the calcium oxalate stone disease. Because the oxalate/calcium molar ratio in the urine is normally 1:10, even slight changes in the urinary oxalate concentration exert much larger effects on the crystallization and stone formation than the comparable changes in the calcium concentration. The urinary oxalate predominantly derived from the endogenous production of the oxalate from the ingested or the metabolically generated precursors and the diet. It has suggested that the dietary oxalate contributes up to 50% of the urinary oxalate excretion. The estimates of the normal dietary oxalate intake are in the range of 50–200 mg/d. The consumption of the foodstuffs rich in the oxalic acid can induce the hyperoxaluria already in healthy individuals without disturbances in oxalate metabolism. Most of the fruits and the vegetables in the typical Western diet contain a low or a moderate concentration of the oxalate. Cereals products play an important role in daily nutrition. The higher oxalate content in the whole-grain (76 mg/100 g) than in refined grain cereals

Fig. 12.2  The oxalic acid is a dicarboxylic acid with the formula C2H2O4. It occurs naturally in many foods, but excessive ingestion of the oxalic acid or prolonged skin contact can be dangerous. Blood concentration is ~1.2 μg/mL

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(17 mg/100 g) suggests that oxalic acid is primarily located in the outer layers of the cereal grains. Thus, the highest soluble and the total oxalate contents found in the wheat bran (Siener et al. 2018). The dietary oxalate reduction is a common practice in the management of the hyperoxaluric stone formers. Some foods such as spinach, rhubarb, and peanuts consistently identified as having high levels of the oxalate and easily identified by the users as the ones to be avoided (Attalla et al. 2014). Some other food items contain some higher oxalate concentrations (Judprasong et  al. 2006) but the whole-­ wheat intake has some different effects: (a) While all the other food items consumed irregularly or at low quantity, the intake of the whole-wheat for refined products might increase remarkably the oxalate intake. (b) The induction of the transformation of the food pattern should carefully be controlled. Subjects with the formation of the urinary stone should consider carefully the consumption of the whole-wheat bread. However, presently the information for this issue is most restricted. With the total oxalate content of ~400  μg/g of the intact kernel (Langenkämper et al. 2006) the contribution of the whole wheat intake in vulnerable subjects should considered.

References Attalla K, De S, Monga M (2014) Oxalate content of food: a tangled web. Urology 84:555–560. https://doi.org/10.1016/j.urology.2014.03.053 Graf E, Eaton JW (1985) Dietary suppression of colonic cancer: fiber or phytate? Cancer 56:717–718 Graf E, Empson K, Eaton JW (1987) Phytic Acid -A natural antioxidant. J Boil Chem 262:11647–11650 Grases F, Simonet BM, Vucenik I, Prieto RM, Costa-Bauzá A, March JG, Shamsuddin AM (2001) Absorption and excretion of orally administered inositol hexaphosphate (IP6 or phytate) in humans. Biofactors 15:53–61. https://doi.org/10.1002/biof.5520150105 Grases F, Isern B, Sanchis P, Perello J, Torres JJ, Costa-Bauza A (2007) Phytate acts as an inhibitor in formation of renal calculi. Front Biosci 12:2580–2587 Hemalatha S, Platel K, Srinivasan K (2007) Zinc and iron contents and their bioaccessibility in cereals and pulses consumed in India. Food Chem 102:1328–1336. https://doi.org/10.1016/j. foodchem.2006.07.015 Jenab M, Thompson LU (2000) Phytic acid in wheat bran affects colon morphology, cell differentiation and apoptosis. Carcinogenesis 21:1547–1552. https://doi.org/10.1093/carcin/21.5.547 Judprasong K, Charoenkiatkul S, Sungpuag P, Vasanachitt K, Nakjamanong Y (2006) Total and soluble oxalate contents in Thai vegetables, cereal grains and legume seeds and their changes after cooking. J Food Compos Anal 19:340–347. https://doi.org/10.1016/j.jfca.2005.04.002 Kumar V, Sinha AK, Makkar HPS, Becker K (2010) Dietary roles of phytate and phytase in human nutrition: a review. Food Chem 120:945–959. https://doi.org/10.1016/j.foodchem.2009.11.052 Langenkämper GL, Zörb C, Seifert M, Mäder P, Fretzdorff B, Betsche T (2006) Nutritional quality of organic and conventional wheat. J Appl Bot Food Qual 80:150–154

References

239

Lönnerdal B (2003) Trace element undernutrition: biology to interventions genetically modified plants for improved trace element nutrition. J Nutr 133:1490–1493 Lopez HW, Leenhardt F, Coudray C, Remesy C (2002) Minerals and phytic acid interactions: is it a real problem for human nutrition? Int J Food Sci Technol 37:727–739. https://doi. org/10.1046/j.1365-2621.2002.00618.x Midorikawa K, Murata M, Oikawa S, Hiraku Y, Kawanishi S (2001) Protective effect of phytic acid on oxidative DNA damage with reference to cancer chemoprevention. Biochem Biophys Res Commun 288:552–557. https://doi.org/10.1006/bbrc.2001.5808 Morgan MSC, Pearle MS (2016) Medical management of renal stones. BMJ 352:1–12. https://doi. org/10.1136/bmj.i52 Oatway L, Vasanthan T, Helm JH (2001) Phytic acid. Food Rev Int 17:419–431. https://doi. org/10.1081/FRI-100108531 Penella JMS, Collar C, Haros M (2008) Effect of wheat bran and enzyme addition on dough functional performance and phytic acid levels in bread. J Cereal Sci 48:715–721. https://doi. org/10.1016/j.jcs.2008.03.006 Plaami S (1997) Myoinositol phosphates: analysis, content in foods and effects in nutrition. LWT Food Sci Technol 30:633–647. https://doi.org/10.1006/fstl.1997.0246 Prynne CJ, McCarron A, Wadsworth MEJ, Stephen AM (2010) Dietary fibre and phytate-a balancing act: results from three time points in a British Birth Cohort. Br J Nutr 103:274–280. https:// doi.org/10.1017/S0007114509991644 Raheem OA, Khandwala YS, Sur RL, Ghani KR, Denstedt JD (2017) Burden of urolithiasis: trends in prevalence, treatments, and costs. Eur Urol Focus 3:18–26. https://doi.org/10.1016/j. euf.2017.04.001 Rosell CM, Santos E, Penella JMS, Haros M (2009) Wholemeal wheat bread: a comparison of different breadmaking processes and fungal phytase addition. J Cereal Sci 50:272–277. https:// doi.org/10.1016/j.jcs.2009.06.007 Schlemmer U, Frølich W, Prieto RM, Grases F (2009) Phytate in foods and significance for humans: food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food Res 53:330–375. https://doi.org/10.1002/mnfr.200900099 Shamsuddin AM (2002) Anti-cancer function of phytic acid. Int J Food Sci Technol 37:769–782. https://doi.org/10.1046/j.1365-2621.2002.00620.x Shamsuddin AKM, Vucenik I (2005) P6 and inositol in cancer prevention and therapy. Curr Cancer Therap Rev 1:259–269 Shamsuddin AM, Vucenik I, Cole KE (1997) Minireview Ip6: a novel anti-cancer. Life Sci 61:343–354 Shi Y, Azab AN, Thompson MN, Greenberg ML (2006) Inositol phosphates and phosphoinositides in health and disease. Subcell Biochem 39:265–292 Siener R, Seidler A, Voss S, Hesse A (2017) Oxalate content of beverages. J Food Compos Anal 63:184–188. https://doi.org/10.1016/j.jfca.2017.08.005 Siener R, Hoppe B, Löhr P, Müller SC, Latz S (2018) Metabolic profile and impact of diet in patients with primary hyperoxaluria. Int Urol Nephrol 50:1583–1589. https://doi.org/10.1007/ s11255-018-1939-1 Wikipedia: https://www.wikipedia.org/

Chapter 13

A Trend in the Decrease in the Wheat Consumption

Changes in the Wheat Intake in Selected Countries High variations have observed in the wheat intake per capita in the countries that consume wheat as the main staple food. The variation in the intake of the other main staple foods such as rice (mainly in Asia), corn (mainly in South America and Africa), and tubers (mainly in Africa, and in some European countries) is the foremost reason for a lower wheat intake in many countries. However, wheat contains a higher content of dietary fiber (except for rye) and differs remarkably from these foods concerning the alleviative nutritional effects supported by evidence-based data. While the nutritional advantage of the wheat products has proved by hundreds of studies and millions of the evaluated subjects in epidemiological studies (Table 15.1), the information for the corn, the rye, and the whole-rice have not accumulated adequate data for a nutritional claim to encourage the intake of the whole-­ grain product. Not so many epidemiological studies have conducted to show the decrease in the relative risks for NCD (non-communicable diseases) for corn, rye, and whole-rice. The high intake of the tubers and in particular the high potato intake might be with nutritional inferiority in comparison to the whole-wheat consumption. Except for the low wheat intake in some of the countries a trend of the decrease in the wheat intake has observed in many countries and presumably a sharp decrease in some of the specific population segments. The increase in the ethanol intake might also affect the balance of grain consumption but no information was gathered for the ethanol as a replacement. The change in the wheat intake between 2003 and 2013 shown for some selected countries (Table 13.1). The wheat consumption (Table 13.1) in the list of the selected countries sorted from the lower to the higher consumption. The consumption for 2004 presented according to the intercepts that calculated for the 10 y period (2004–2013) according to the FADSTAT data. In many countries (Table 13.1) the wheat comprises the main staple carbohydrate item but, China and India, which with the substantial part of humanity, kept on the list. The table presents also whole-grain consumption. © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_13

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Table 13.1  The total wheat intake versus the whole-wheat intake in various countries (FAOSTAT: Food and agriculture data)

Latvia Cyprus Australia Netherlands Belarus Finland Germany Sweden Slovenia Luxembourg Spain US Austria Estonia Canada Switzerland Portugal UK France Belgium Norway Ireland Denmark Czechia Poland Hungary Chile Israel Lithuania Ukraine Iraq Kazakhstan Greece Russia Egypt Romania Italy Iran

Wheat consumption Total wheat Intake intercept kg/capita/ya 60 60 65 67 70 80 80 82 82 82 84 85 87 87 89 92 94 98 98 101 102 104 105 108 108 110 112 121 123 124 124 128 128 132 139 142 148 159

Dietary fiberc Whole-grain Δ/decade, %b 16 39 14 9 −13 2 7 −5 25 36 13 −5 −8 8 −7 −1 −1 0 12 13 −4 8 −5 −13 1 −2 −7 −5 −5 −18 11 −29 −7 0 6 −8 −1 −5

g/d 24 32 71 90 24 74 135 83 20 71 10 48 69 25 57 75 73 76 13 13 75 69 76 13 17 1 33 48 23 76 71 22 47 24 12 12 10 13

g/d 17.2 22 21.2 19 17 20.4 22 16.8 25.5 15.4 19.2 15.8 18.5 19.7 17.1 19.4 20.5 13.3 16.9 18.5 20.4 15.1 18.4 23.2 20.5 20.7 14.5 20.1 17.9 19.3 18.8 15.5 21.6 16.9 22.2 21.4 18.6 13.1 (continued)

243

Changes in the Wheat Intake in Selected Countries Table 13.1 (continued)

Uzbekistan Turkey India China Japan Chad Indonesia Namibia Eritrea Ethiopia Mali Cameron Guinea Congo Myanmar

Wheat consumption Total wheat Intake intercept kg/capita/ya 168 206 61 64

Dietary fiberc Whole-grain Δ/decade, %b 1 −18 0 −8

g/d 27 5 25 13 75 250 248 234 231 200 199 198 185 149 104

g/d 18.5 23.4 23.4 10.3 15 32 16.4 24.9 28.3 27.5 25.2 28.5 20.4 23 15.6

The intercept of the consumption data calculated for the period of 2004–2013 Change of the consumption calculated according to the slope for the period of 2004–2013 c FAOSTAT: Food and agriculture data a

b

The decrease in the wheat intake in some of the countries might have a high concern issue for the general trend of the wheat intake. The consistent decrease in North America might have an influential effect on all of all the Western countries. In some of the countries with wheat intake with 200 g/d. With the general trend in many countries, to consume the wholewheat for the refined flour the dynamic information for the whole-wheat consumption become a remarkable pillar in the future planning of the nutritional policy. In a survey conducted in Sweden with a comparative high intake of 83 g/d of whole-grain, >33% of the respondents reported eating mainly white bread. The socio-demographic, geographic, and lifestyle-related factors are associated with what type of bread consumed. Development of more sensorily attractive rye or whole-grain-rich bread and eating-out types of bread is thus a challenge. Target groups for health c­ ommunication strategies and product development should be younger age groups (18–30 years), families with children, and groups with lower educational levels (Sandvik et al. 2014).

The Consumer Preference

247

Within recent years, the international and the national health authorities have tried unsuccessfully to encourage the consumption of whole-wheat bread for the refine-flour bread. Still, the vast majority of the wheat consumed after most of the nutritious ingredients have sieved followed milling and diverted for the animal husbandry feeding. The benefits of the whole-wheat have mainly presented as a food item with the higher dietary fiber content while almost ignoring the major role in the antioxidant intake and many other compounds that have listed formerly in this book.

The Consumer Preference Foods with health benefits need to have high sensory acceptance, and it is of great importance to identify the causes of the sensory concerns in wholegrain foods. In addition to the sensory product properties, extrinsic properties such as packaging, product information, and nutritional claims influence consumer preference. The preferences for the sensory attributes found in the refined bread often stated as the reason for the relatively low consumption of the whole-wheat bread and the other wholegrain cereal foods. The health information of the cereal products induces the sensory and the hedonic expectations, and these expectations must fulfilled during consumption. The motivational factors underpinning the consumer understanding of the health claims showed that the nutritional improvements of the staple foods perceived as more beneficial for health than the health claims of the fun foods. The consumers generally seem to regard cereal products as good for their health. However, the awareness of the whole-grain products being healthier for you than the refined grain products varied among the consumer groups (Heiniö et al. 2016). The consumer preference for the refined bread often cited as a reason for the relatively low consumption of the whole-wheat bread, but only a few studies have examined the consumer preferences between the refined and the whole-wheat bread. In an examination of the preferences in the US armed forces, refined bread was preferred to whole-wheat bread. In a study of the relatively older consumers with cancer patients, and age-matched controls the participants preferred the whole-­wheat bread to refined bread. Studies in children showed controversial outcomes. A segment of the consumer population liked refined bread better than the whole-wheat bread, indicating that sensory properties are a barrier to the consumption of the whole-wheat bread. A large proportion of the participants, however, liked the commercially available samples of the refined and the whole-wheat bread equally well, which may indicate that the taste is not as great a barrier as has previously assumed. The participants who stated a preference for and chose to eat the refined bread liked the refined bread better in all 4 comparisons between the comparable refined and the whole-wheat bread. The participants who stated a preference for the whole-wheat bread were less consistent, liking the refined bread better in some cases and the whole-wheat bread in others.

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Non-celiac Gluten Sensitivity Non-celiac gluten sensitivity (NCGS) consists of a spectrum of intestinal and extra-­ intestinal symptoms related to the ingestion of the gluten-containing food, in the absence of the celiac disease or wheat allergy. It has gained attention as an emerging clinical entity in the last decade, though there is still a diagnostic uncertainty surrounding the disorder. Interestingly, there was an impressive increase in the popularity of the gluten-free diet (GFD) in Western societies. According to some surveys, 21% of the Americans consume gluten-free-diet (Catassi and Fasano 2016) while the prevalence of the celiac disease is 200  μg/g and a considerable part of the naturally GFD had a gluten content of >200  μg/g. In a wide-scaled survey for Europe, the US and Canada 19% of the samples had the undetectable levels of the gluten, whereas 81% were contaminated with a mixture of wheat, barley, and rye, but the predominant contaminant was the barley. Therefore, the use of oats has not widely recommended (Poley 2017). The uncontaminated oats consumed by >70% of the patients with celiac disease in countries such as Sweden, Finland, and The Netherlands and at least 1 randomized trial found that the oats do not induce antibody responses in children with the celiac disease. The Canadian Celiac Association notes that it is possible to produce oats without contamination from other grains and that in the well-controlled individuals the incorporation of up to 50–70 g/d of pure oats may be possible (Williams 2014). The oat probably contains much higher total polyphenolic capacity than the whole-­ wheat with similar content of dietary fiber but without comprehensive studies comparing the nutritious quality to that of the whole-wheat (Vitaglione et  al. 2008; Soong et  al. 2014). In the patients with the celiac disease consuming oats for 12 months, no deterioration in the gastrointestinal symptoms observed. Current evidence suggests that uncontaminated oats can use in patients with the celiac disease but there is still a need for more rigorous data (Pinto-Sánchez et al. 2017). Most of the non-contaminated oat varieties contain avenin epitopes that are potentially harmful to a minority of the celiac disease patient population. Similarly, to the situation in the wheat, not all oat varieties display the same immunogenic profile, suggesting that the selection and breeding of oat varieties that have a

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lower risk profile or have no risk at all for celiac disease patients may be realistic. The T cell line will be useful to detect differences in the immunogenic potential of the oat material (such as flakes and flour) derived from selected varieties (Mujico et al. 2011). There is a significant difference among oat cultivars in eliciting the very precocious events occurring at the cell surface and triggering the downstream mucosa inflammation in the celiac disease. The inclusion of oats in a celiac disease diet might be valuable for the nutritional and health anti-gliadin polyclonal antibodies (Silano et al. 2014). The introduction of the oats is most crucial because the gluten-free diet cannot be regarded as a healthy diet. Gluten-free products are usually made with starches or refined flours characterized by low fiber content. It is known that the consumption of adequate amounts of dietary fiber is related to important health benefits such as prevention of colon cancer, diabetes type 2 and cardiovascular disease. Thus, the gluten-free diet may lead to possible nutrient deficiencies in fiber resulting in consequent diseases. The gluten-free diet also leads to deficiency in Vitamins C, B12, D, and folic acid, which is associated not only with malabsorption caused by villi atrophy but also with low quality of the gluten-free diet (Balakireva and Zamyatnin 2016).

The Low Carbohydrate Diet The US consumption of wheat products such as bread, pasta, and pizza dropped sharply beginning in 2000, reversing a three-decade trend of growth in per-capita consumption. Wheat consumption fell from ~ 66  kg/person in 2000 to a low of 60.5 kg/person in the mid-2000s, recovered slightly, then dropped back to 60.1 kg/ person for 2011. The drop from 2000 reflected the public interest in lowering carbohydrate consumption. Interestingly, the rise in wheat consumption that started some 30 y ago has triggered by health concerns. In the 1970s, American began shifting from animal products to grain-based foods, including wheat products, because of concerns about cholesterol and heart diseases (Bond and Liefert 2019). The trend to drop the wheat intake does not restrict to the US and presumably motivated by the same trend of the advertising industry to decrease the carbohydrate intake. From 1980 to 2015, a continuous decrease in the wheat consumption observed in the developed countries worldwide from 139 to 125 kg/capita (Awika et al. 2011). The decrease in wheat consumption has encouraged by aggressive advertising and a long list of clinical trials that showed the advantage of the low-carbohydrate diet to induce body weight reduction. The low carbohydrate diets that exchange carbohydrates for protein and fat have gained substantial popularity because of their ability to induce short-term weight loss (Seidelmann et al. 2018). A prospective cohort long-run study and meta-analysis conducted in 15 k and 432 k subjects respectively showed the nadir of the carbohydrate intake at the 50% of the total energy intake for the lowest relative risk of mortality. At the lower 30% and the higher 80% carbohydrate consumption, of the total energy intake, a relative

References

261

risk of ~1.3 shown and at 40% and 70% carbohydrate intake the relative risk for mortality was ~1.13 (Seidelmann et al. 2018). This finding based on very extensive studies strongly contradicts the prevailed opinion on the nutritional advantage of the low-carbohydrate diet. Apparently, in all of the studies that show the advantage of moderate carbohydrate consumption (50% of the total energy) the vast majority of the carbohydrate intake derived from the refined-wheat products which are the most common food items consumed for the reference of the lowest relative risk. With the intake of the whole-wheat products for the refined flour products, a further decrease in the relative risk foreseen and the advantage of the optimal carbohydrate diet will emphasis (Seidelmann et al. 2018). The conclusion that the 50% carbohydrate diet stands as the superior clue for the longer longevity and presumably for the lower relative risk of morbidity and disability on aging, might be the cornerstone of any nutritional recommendation. However, another most important conclusion has derived from the cited study that any practical nutritional recommendation must support on the long run of extensive epidemiologic nutritional studies.

References Arias-Gastelum M, Cabrera-Chávez F, Jesús MD, Vergara-Jiménez M, Ontiveros N (2018) The gluten-free diet: access and economic aspects and impact on lifestyle. Nutr Diet Suppl 10:27– 34. https://doi.org/10.2147/nds.s143404 Awika JM, Piironen V, Bean S (eds) (2011) advances in cereal science: implications to food processing and health promotion. ACS Division of Agricultural and Food Chemistry, Inc. https:// doi.org/10.1021/bk-2011-1089.fw001 Aziz I, Sanders DS (2012) The irritable bowel syndrome-celiac disease connection. Gastrointest Endosc Clin N Am 22:623–637. https://doi.org/10.1016/j.giec.2012.07.009 Aziz I, Sanders DS (2014) Patients who avoid wheat and gluten: is that health or lifestyle? Dig Dis Sci 59:1080–1082. https://doi.org/10.1007/s10620-014-3083-9 Aziz I, Lewis NR, Hadjivassiliou M, Winfield SN, Rugg N, Kelsall A, Newrick L, Sanders DS (2014) A UK study assessing the population prevalence of self-reported gluten sensitivity and referral characteristics to secondary care. Eur J Gastroenterol Hepatol 26:33–39. https://doi. org/10.1097/01.meg.0000435546.87251.f7 Balakireva AV, Zamyatnin AA (2016) Properties of gluten intolerance: gluten structure, evolution, pathogenicity and detoxification capabilities. Nutrients 8:644. https://doi.org/10.3390/ nu8100644 Biesiekierski JR, Peters SL, Newnham ED, Rosella O, Muir JG, Gibson PR (2013) No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology 145:320–328.e3. https://doi.org/10.1053/j.gastro.2013.04.051 Biesiekierski JR (2017) What is gluten? J Gastroenterol Hepatol 32:78–81. https://doi.org/10.1111/ jgh.13703 Böhn L, Störsrud S, Liljebo T, Collin L, Lindfors P, Törnblom H, Simrén M (2015) Diet low in FODMAPs reduces symptoms of irritable bowel syndrome as well as traditional dietary advice: a randomized controlled trial. Gastroenterology 149:1399–1407.e2. https://doi.org/10.1053/j. gastro.2015.07.054

262

13  A Trend in the Decrease in the Wheat Consumption

Bond JK, Liefert O (2019) Wheat outlook: 2019/20 wheat production, feed and residual lifted, exports continue to face headwinds. https://www.ers.usda.gov/webdocs/publications/93304/ whs-19f.pdf?v=5914.4 Bouziat R, Hinterleitner R, Brown JJ, Stencel-Baerenwald JE, Ikizler M, Mayassi T, Meisel M, Kim SM, Discepolo V, Pruijssers AJ, Ernest JD, Iskarpatyoti JA, Costes LMM, Lawrence I, Palanski BA, Varma M, Zurenski MA, Khomandiak S, McAllister N, Aravamudhan P, Boehme KW, Hu F, Samsom JN, Reinecker HC, Kupfer SS, Guandalini S, Semrad CE, Abadie V, Khosla C, Barreiro LB, Xavier RJ, Ng A, Dermody TS, Jabri B (2017) Reovirus infection triggers inflammatory responses to dietary antigens and development of celiac disease. Science 356:44–50. https://doi.org/10.1126/science.aah5298 Branchi F, Aziz I, Conte D, Sanders DS (2015) Noncoeliac gluten sensitivity: a diagnostic dilemma. Curr Opin Clin Nutr Metab Care 18:508–514. https://doi.org/10.1097/ MCO.0000000000000207 Brottveit M, Beitnes AC, Tollefsen S, Bratlie JE, Jahnsen FL, Johansen FE, Sollid LM, Lundin KE (2013) Mucosal cytokine response after short-term gluten challenge in celiac disease and non-­ celiac gluten sensitivity. Am J Gastroenterol 108:842–850. https://doi.org/10.1038/ajg.2013.91 Brouns FJPH, Buul VJV, Shewry PR (2013) Does wheat make us fat and sick? J Cereal Sci 58:209–215. https://doi.org/10.1016/j.jcs.2013.06.002 Buul VJV, Brouns FJPH (2014) Health effects of wheat lectins: a review. J Cereal Sci 59:112–117. https://doi.org/10.1016/j.jcs.2014.01.010 Caio G, Volta U, Tovoli F, Giorgio RD (2014) Effect of gluten free diet on immune response to gliadin in patients with non-celiac gluten sensitivity. BMC Gastroenterol 14:26. http://www. biomedcentral.com/1471-230X/14/ Carroccio A, Mansueto P, Iacono G, Soresi M, D’Alcamo A, Cavataio F, Brusca I, Florena AM, Ambrosiano G, Seidita A, Pirrone G, Rini GB (2012) Non-celiac wheat sensitivity diagnosed by double-blind placebo-controlled challenge: exploring a new clinical entity. Am J Gastroenterol 107:1898–1906. https://doi.org/10.1038/ajg.2012.236 Catassi C, Fasano A (2016) Tempters and gluten-free diet. Nutrients 8:786. https://doi.org/10.3390/ nu8120786 Cruchet S, Lucero Y, Cornejo V (2016) Truths, myths and needs of special diets: attention-­deficit/ hyperactivity disorder, autism, non-celiac gluten sensitivity, and vegetarianism. Ann Nutr Metab 68:43–50. https://doi.org/10.1159/000445393 Dickerson F, Stallings C, Origoni A, Vaughan C, Khushalani S, Leister F, Yang S, Krivogorsky B, Alaedini A, Yolken R (2010) Markers of gluten sensitivity and celiac disease in r­ ecent-­onset psychosis and multi-episode schizophrenia. Biol Psychiatry 68:100–104. https://doi. org/10.1016/j.biopsych.2010.03.021 Dietary Guidelines for Americans (2015) U.S.  Department of Health and Human Services and U.S.  Department of Agriculture. 2015–2020 Dietary guidelines for Americans, 8th edn. December 2015. http://health.gov/dietaryguidelines/2015/guidelines/. Accessed 24 Feb 2017. 1–46. https://doi.org/10.1097/NT.0b013e31826c50af Digiacomo DV, Tennyson CA, Green PH, Demmer RT (2013) Prevalence of gluten-free diet adherence among individuals without celiac disease in the USA: results from the continuous national health and nutrition examination survey 2009–2010. Scand J Gastroenterol 48:921–925. https:// doi.org/10.3109/00365521.2013.809598 Eswaran SL, Chey WD, Han-Markey T, Ball S, Jackson K (2016) A randomized controlled trial comparing the low FODMAP diet vs. modified NICE guidelines in US adults with IBS-D. Am J Gastroenterol 111:1824–1832. https://doi.org/10.1038/ajg.2016.434 FAOSTAT: http://www.fao.org/faostat/en/#home Fasano A, Catassi C (2012) Celiac disease. N Engl J Med 367:2419–2426. https://doi.org/10.1056/ NEJMcp1113994 Flasar M, Patil S (2014) Radiating disparity in IBD.  Dig Dis Sci 59:504–506. https://doi. org/10.1007/s10620-013-2922-4

References

263

Fritscher-Ravens A, Schuppan D, Ellrichmann M, Schoch S, Röcken C, Brasch J, Bethge J, Böttner M, Klose J, Milla PJ (2014) Confocal endomicroscopy shows food-associated changes in the intestinal mucosa of patients with irritable bowel syndrome. Gastroenterology 147:1012–1020. e4. https://doi.org/10.1053/j.gastro.2014.07.046 Gibson PR, Shepherd SJ (2012) Food choice as a key management strategy for functional gastrointestinal symptoms. Am J Gastroenterol 107:657–666. https://doi.org/10.1038/ajg.2012.49 Giorgio RD, Volta U, Gibson PR (2016) Sensitivity to wheat, gluten and FODMAPs in IBS: facts or fiction? Gut 65:169–178. https://doi.org/10.1136/gutjnl-2015-309757 Golley S, Corsini N, Topping D, Morell M, Mohr P (2015) Motivations for avoiding wheat consumption in Australia: results from a population survey. Public Health Nutr 18:490–499. https://doi.org/10.1017/S1368980014000652 Guandalini S, Assiri A (2014) Celiac disease: a review. JAMA Pediatr 168:272–278. https://doi. org/10.1001/jamapediatrics.2013.3858 Haas H, Falcone FH, Schramm G, Haisch K, Gibbs BF, Klaucke J, Pöppelmann M, Becker W-M, Gabius H-J, Schlaak M (1999) Dietary lectins can inducein vitro release of IL-4 and IL-13 from human basophils. Eur J Immunol 29:918–927. https://doi.org/10.1002/ (sici)1521-4141(199903)29:033.0.co;2-t Hadjivassiliou M, Sanders DS, Grünewald RA, Woodroofe N, Boscolo S, Aeschlimann D (2010) Gluten sensitivity: from gut to brain. Lancet Neurol 9:318–330. https://doi.org/10.1016/ S1474-4422(09)70290-X Hadjivassiliou M, Rao DG, Grìnewald RA, Aeschlimann DP, Sarrigiannis PG, Hoggard N, Aeschlimann P, Mooney PD, Sanders DS (2016) Neurological dysfunction in coeliac disease and non-coeliac gluten sensitivity. Am J Gastroenterol 111:561–567. https://doi.org/10.1038/ ajg.2015.434 Halmos EP, Power VA, Shepherd SJ, Gibson PR, Muir JG (2014) A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology 146:67–75.e5. https://doi. org/10.1053/j.gastro.2013.09.046 Heiniö RL, Noort MWJ, Katina K, Alam SA, Sozer N, de Kock HL, Hersleth M, Poutanen K (2016) Sensory characteristics of wholegrain and bran-rich cereal foods – a review. Tr Food Sci Technol 47:25–38. https://doi.org/10.1016/j.tifs.2015.11.002 Huebener S, Tanaka CK, Uhde M, Zone JJ, Vensel WH, Kasarda DD, Beams L, Briani C, Green PHR, Altenbach SB, Alaedini A (2015) Specific nongluten proteins of wheat are novel target antigens in celiac disease humoral response. J Proteome Res 14:503–511. https://doi. org/10.1021/pr500809b Infanti-no M, Manfredi M, Meacci F, Grossi V, Severino M, Benucci M, Bellio E, Bellio V, Nucci A, Zolfanelli F, Ugolini S, Catani S, Macchia D (2015) Diagnostic accuracy of anti-gliadin antibodies in non celiac gluten sensitivity (NCGS) patients: a dual statistical approach. Clin Chim Acta 451:135–141. https://doi.org/10.1016/j.cca.2015.09.017 Junker Y, Zeissig S, Kim S-J, Barisani D, Wieser H, Leffler DA, Zevallos V, Libermann TA, Dillon S, Freitag TL, Kelly CP, Schuppan D (2012) Wheat amylase trypsin inhibitors drive intestinal inflammation via activation of toll-like receptor 4. J Exp Med 209:2395–2408. https://doi. org/10.1084/jem.20102660 Kim HS, Demyen MF, Mathew J, Kothari N, Feurdean M, Ahlawat SK (2017) Obesity, metabolic syndrome, and cardiovascular risk in gluten-free followers without celiac disease in the United States: results from the National Health and Nutrition Examination Survey 2009–2014. Dig Dis Sci 62:2440–2448. https://doi.org/10.1007/s10620-017-4583-1 Lebwohl B, Cao Y, Zong G, Hu FB, Green PHR, Neugut AI, Rimm EB, Sampson L, Dougherty LW, Giovannucci E, Willett WC, Sun Q, Chan AT (2017) Long term gluten consumption in adults without celiac disease and risk of coronary heart disease: prospective cohort study. BMJ 357:j1892. https://doi.org/10.1136/bmj.j1892 Lee AR, Wolf RL, Lebwohl B, Ciaccio EJ, Green PHR (2019) Persistent economic burden of the gluten free diet. Nutrients 11:399. https://doi.org/10.3390/nu11020399

264

13  A Trend in the Decrease in the Wheat Consumption

Leonard MM, Sapone A, Catassi C, Fasano A (2017) Celiac disease and nonceliac gluten168 sensitivity: a review. JAMA J Am Med Assoc 318:647–656. https://doi.org/10.1001/jama.2017.9730 Lin BH, Yen ST (2007) The US grain consumption landscape: who eats grain, In: What form, where, and how much? ERR-50. USDA, Econ Res Serv. https://naldc.nal.usda.gov/download/19453/ PDF Lis DM, Stellingwerff T, Shing CM, Ahuja KDK, Fell JW (2013) Exploring the popularity, experiences, and beliefs surrounding gluten-free diets in nonceliac athletes. Inter J Sport Nutr Exercise Metabol 25:37–45. https://doi.org/10.1123/ijsnem.2013-024 Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC (2006) Functional bowel disorders. Gastroenterology 130:1480–1491. https://doi.org/10.1053/j. gastro.2005.11.061 Magalis RM, Giovanni M, Silliman K (2016) Whole-grain foods: is sensory liking related to knowledge, attitude, or intake? Nutr Food Sci 46:488–503. https://doi.org/10.1108/ NFS-09-2015-0101 Missbach B, Schwingshackl L, Billmann A, Mystek A, Hickelsberger M, Bauer G, König J (2015) Gluten-free food database: the nutritional quality and cost of packaged gluten-free foods. PeerJ 3:e1337. https://doi.org/10.7717/peerj.1337 Molina-Infante J, Carrocc A (2017) Suspected nonceliac gluten sensitivity confirmed in few patients after gluten challenge in double-blind, placebo-controlled trials. Clin Gastroenterol Hepatol 15:339–348. https://doi.org/10.1016/j.cgh.2016.08.007 Mujico JR, Mitea C, Gilissen LJWJ, Ru AD, Veelen PV, Smulders MJM, Koning F (2011) Natural variation in avenin epitopes among oat varieties: implications for celiac disease. J Cereal Sci 54:8–12. https://doi.org/10.1016/j.jcs.2010.09.007 Murray K, Wilkinson-Smith V, Hoad C, Costigan C, Cox E, Lam C, Marciani L, Gowland P, Spiller RC (2014) Differential effects of FODMAPs (Fermentable Oligo-, Di-, Mono-Saccharides and Polyols) on small and large intestinal contents in healthy subjects shown by MRI. Am J Gastroenterol 109:110–119. https://doi.org/10.1038/ajg.2013.386 Newberry C, McKnight L, Sarav M, Pickett-Blakely O (2017) Going gluten free: the history and nutritional implications of today’s most popular diet. Curr Gastroenterol Rep 19:54. https://doi. org/10.1007/s11894-017-0597-2 Panagiotou S, Kontogianni MD (2017) The economic burden of gluten-free products and gluten-­ free diet: a cost estimation analysis in Greece. J Hum Nutr Diet 30:746–752. https://doi. org/10.1111/jhn.12477 Pellegrina CD, Perbellini O, Scupoli MT, Tomelleri C, Zanetti C, Zoccatelli G, Fusi M, Peruffo A, Rizzi C, Chignola R (2009) Effects of wheat germ agglutinin on human gastrointestinal epithelium: insights from an experimental model of immune/epithelial cell interaction. Toxicol Appl Pharmacol 237:146–153. https://doi.org/10.1016/j.taap.2009.03.012 Pember SE, Rush SE (2016) Motivation for gluten-free diet adherence among adults with and without a clinically diagnosed gluten-related illness. Californian J Health Promotion 14:68–73 Pinto-Sánchez MI, Verdu EF, Liu E, Bercik P, Green PH, Murray JA, Guandalini S, Moayyedi P (2016) Gluten introduction to infant feeding and risk of celiac disease: systematic review and meta-analysis. J Pediatr 168:132–143. https://doi.org/10.1016/j.jpeds.2015.09.032 Pinto-Sánchez MI, Causada-Calo N, Bercik P, Ford AC, Murray JA, Armstrong D, Semrad C, Kupfer SS, Alaedini A, Moayyedi P, Leffler DA, Verdú EF, Green P (2017) Safety of adding oats to a gluten-free diet for patients with celiac disease: systematic review and meta-analysis of clinical and observational studies. Gastroenterology 153:395–409. https://doi.org/10.1053/j. gastro.2017.04.009 Poley JR (2017) The gluten-free diet: can oats and wheat starch be part of it? J Am Coll Nutr 36:1–8. https://doi.org/10.1080/07315724.2015.1085815 Raehsler SL, Choung RS, Marietta EV, Murray JA (2018) Accumulation of heavy metals in people on a gluten-free diet. Clin Gastroenterol Hepatol 16:244–251. https://doi.org/10.1016/j. cgh.2017.01.034

References

265

Reilly NR (2016) The gluten-free diet: recognizing fact, fiction, and fad. J Pediatr 175:206–210. https://doi.org/10.1016/j.jpeds.2016.04.014 Roman L, Belorio M, Gomez M (2019) Gluten-free breads: the gap between research and commercial reality. Compr Rev Food Sci Food Saf 18:690–702. https://doi.org/10.1111/1541-4337.12437 Rosenbaum JT (2017) Celiac disease and autoimmunity -the missing ingredient. N Engl J Med 377:1489–1490. https://doi.org/10.1056/nejmcibr1706917 Sandvik P, Kihlberg I, Lindroos AK, Marklinder I, Nydahl M (2014) Bread consumption patterns in a Swedish national dietary survey focusing particularly on whole-grain and rye bread. Food Nutr Res 58:24024. https://doi.org/10.3402/fnr.v58.24024 Seidelmann SB, Claggett B, Cheng S, Henglin M, Shah A, Steffen LM, Folsom AR, Rimm EB, Willett WC (2018) Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis. Lancet Public Health 3:e419–e428. https://doi.org/10.1016/ S2468-2667(18)30135-X Shewry P (2016) Editorial. J Cereal Sci 70:A1. https://doi.org/10.1016/j.jcs.2016.07.012 Shewry PR, Hey SJ (2016) Do we need to worry about eating wheat? Nutr Bull 41:6–13. https:// doi.org/10.1111/nbu.12186 Silano M, Penas Pozo E, Uberti F, Manferdelli S, Pinto TD, Felli C, Budelli A, Vincentini O, Restani P (2014) Diversity of oat varieties in eliciting the early inflammatory events in celiac disease. Eur J Nutr 53:1177–1186. https://doi.org/10.1007/s00394-013-0617-4 Soong YY, Tan SP, Leong LP, Henry JK (2014) Total antioxidant capacity and starch digestibility of muffins baked with rice, wheat, oat, corn and barley flour. Food Chem 164:462–469. https:// doi.org/10.1016/j.foodchem.2014.05.041 Tanpowpong P, Ingham T, Lampshire P, Kirchberg FF, Epton MJ, Crane J, Camargo CA, Dench C, Duignan M, Fishwick D, Fitzharris P, Irvine V, Kelly R, Lane J, Leadbitter P, MacDonald C, McCartin F, McLeod S, Nicholson A, Pattemore P, Roff K, Sawyer G, Siebers R, Town GI, Wickens K, Wilson H, Withell K (2012) Coeliac disease and gluten avoidance in New Zealand children. Arch Dis Child 97:12–16. https://doi.org/10.1136/archdischild-2011-300248 Usfar AA, Takano T, Zhang J (2011) Progress of dietary guidelines in Asia: an introduction. Asia Pac J Clin Nutr 20:438 Valerii MC, Ricci C, Spisni E, Silvestro RD, Fazio LD, Cavazza E, Lanzini A, Campieri M, Dalpiaz A, Pavan B, Volta U, Dinelli G (2015) Responses of peripheral blood mononucleated cells from non-celiac gluten sensitive patients to various cereal sources. Food Chem 176:167–174. http://creativecommons.org/licenses/by-nc-nd/4.0/ Vici G, Belli L, Biondi M, Polzonetti V (2016) Gluten free diet and nutrient deficiencies: a review. Clin Nutr 35:1236–1241. https://doi.org/10.1016/j.clnu.2016.05.002 Vitaglione P, Napolitano A, Fogliano V (2008) Cereal dietary fibre: a natural functional ingredient to deliver phenolic compounds into the gut. Tr Food Sci Technol 19:451–463. https://doi. org/10.1016/j.tifs.2008.02.005 Volta U, Bardella MT, Calabrò A, Troncone R, Corazza GR (2014) An Italian prospective multicenter survey on patients suspected of having non-celiac gluten sensitivity. BMC Med 12:4–11. https://doi.org/10.1186/1741-7015-12-85 Williams PG (2014) The benefits of breakfast cereal consumption: a systematic review of the evidence base. Adv Nutr 5:636S–673S. https://doi.org/10.3945/an.114.006247 Wu JHY, Neal B, Trevena H, Crino M, Stuart-Smith W, Faulkner-Hogg K, Louie JCY, Dunford E (2015) Are gluten-free foods healthier than non-gluten-free foods? An evaluation of supermarket products in Australia. Br J Nutr 114:448–454. https://doi.org/10.1017/s0007114515002056

Chapter 14

Digestion

The common nutritional terminology defines digestion as the total activity of the food decomposition in the gut and/or the distinct activities that undergo at the upper gut. The digesta decomposition at the lower gut (the colon) commonly defined as fermentation. At the upper gut, the decomposition enhances by the enzymes excreted by eukaryotic cells in the upper gut mucosal cells, in the stomach, the pancreas and the intestinal mucosa. The digesta decomposition in the colon enhances mainly by the enzymes released by the microbiota into the colon lumen or by the phagocytosis of the food particles and decomposition the fragment inside the microbiota organisms. The upper gut segments contain very high concentrations of the bile acids, flow into the duodenum, which disrupts the microbiota membranes. Thus, the activity of the commensal microbiota in the upper gut is negligible. At the terminal ileum segment, the bile transporters at the ileum mucosa absorb a considerable amount of the bile acids into the portal bloodstream and give rise to the most accelerated multiplication rate of the microbiota. With the increase in the microbiota population, the fermentation activity soars. Concomitantly, the marked reduction of the bile acids enables the ileal mucosa to absorb the major content of the gut water. The high fluctuation in the number of the microbiota species (Table 14.1, Shannon index) along the gut, suggests a continuous and vigorously microbiota multiplication along with all colon segments. The human has a high colon capacity (in comparison to the other primates, and the highest microbiota count, higher than for all the other primates. The reason for such a high capacity has not well explained. Presumably, because the colon has a particular role in the induction of the immune capacity, the human has developed a very high colon activity to encourage the immune capacity. (continued)

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_14

267

268

14 Digestion

(continued) With an adequate intake, the whole-wheat supplies the major mass of the insoluble dietary fiber in our menu and the major mass of the bound antioxidants and thus exerts a specific effect in the colon to increase remarkably the fecal excretion. The bound antioxidants (mainly polyphenols) of the wholewheat that reach the colon released by the microbiota activity from the digesta and mixed up with the colon digesta. The phenol mass released in the colon is much higher than that of all the phenol mass delivered into the colon that derived from fruits and vegetables. These released antioxidants increase remarkably the blood antioxidant capacity. Some other bound ingredients of the whole-wheat released also in the colon. When the whole-­wheat consumed at a high rate (>20% of the total energy intake) the whole-­wheat supplies the main energy needs of the colon microbiota by its high content of the dietary fiber. We still do not acquaint with all of the digestion and fermentation activities of the whole-wheat decomposition and their direct effects on the induction of the immune system. Therefore, a detailed description of the digestion system is required to understand how the whole-wheat is utilized in our body and the unique effects exerted by its activity. The whole-wheat its typically digested in the 2 main compartments namely, the upper and the lower gut. The major benefits of the whole-wheat ingredients presumably arise at the lower gut where the bound polyphenols released. The main food mass decomposed and absorbed in the small intestine and the residues with the low utilization rate, decomposed at the colon by the microbiota. The metabolic mechanism of the microbiota, like it, would “prefer” to utilize simple compounds such as mono carbohydrates rather than working hard to decompose the cellulose and the other poly carbohydrates and thus waste the simple compounds that targeted directly for the human metabolism. The 3 main gut segments, the stomach, the small intestine, and the colon (the lower gut), have a distinct mechanism for the control of the microbiota activity. While the esophagus with the high flow rate of the digesta contains ~104 counts/mL microbiota, in the stomach with the high acid secretion and the low pH, the count reduces to 103/mL, and in the jejunum, with the high bile concentration, the count preserves at 103/mL (Walker and Talley 2014). The colon count mainly refers to the bacteria identified for some phyla that comprise ~0.99 of the all microorganisms with the negligible count of fungi and yeast, and some small count of archaea. Also a huge amount of bacteriophages (viruses) habitats each bacterium with ~10 units. With the regular count of the colon flora the bacteriophages are not considered. In the stomach, a flux of 10–30 mEq H+/h keeps a low pH and prevents microbial activity. In the duodenum and downwards the bile flux preserves the low microbiota count. The gigantic number of the bacteria species and the high diversity in bacteria along the colon and between subjects are typical characteristics of the colon inhabitant.

Small intestine

Pancreas Liver synthesis Gall bladder

Oral cavity Dental plaque Saliva Esophagus Stomach

Segment

Duodenum Jejunum Ileum proximal terminal

fundus body Pyloric antrum

?

22 250 350

650

25 30

cm

2.5 2.4 2.0

2.6

cm

mL

cm2

2000

1000

1300

108

5 × 103 8 × 106 108

103

1011 109 104 1500 5 × 103

mL/d 1000

Count Surface Length Width Volume area H2Oa per mL

Table 14.1  The gut segments characterizations

7.5 8

6 8

3

5.5 2

10

300

pH SCFAb Bilec Pool mM mM g 7

20– 30

0.8

4.7 (4.33–5.10)

2.68 (2.48–3.10)

Flow g/d h 0.014

Transit Time

155

cm

From Anusd

(continued)

4.15

Shannon Indexe

14 Digestion 269

200 160

57 200 360 160 310 150

60 240 1011

108

7.4

6.3

5.4 15 6 40 7.8

0.4

0.03 0.005 0.005 10– 12

5 3.5 3.5 6.5

0.7 8 6

Feces 9 × 1010 Portal blood Peripheral blood Digesta flows at a rate of 9–18 cm/min and at a frequency of 2.6–3 waves/min Gastric acid secreted into the stomach at a flow of 10–30 mEq H+/h

9 7 fast 23 fed 58 33 49 20 4

pH SCFAb Bilec Pool

0.06

transverse descending sigmoid rectum anus

appendix cecum ascending

200f

Count Surface Length Width Volume area H2Oa per mL

Whole gut

Colon

Segment

Table 14.1 (continued)

3–5

0.8

Flow

28.9 F 30.5 M 27.2

21.1 23.9–30.8

Transit Time

109 64 20 10

150 142

From Anusd

3.52 3.6 3.73 3.78

3.73 3.45

Shannon Indexe

270 14 Digestion

Sadahiro et al. (1992), Cremer et al. (2017), Pritchard et al. (2014), Hofmann and Hagey (2014), Cronin et al. (2010), Sundin et al. (2017), Vertzoni et al. (2019), Nandhra et al. (2019) a Water secreted into the gut lumen at the total rate of ~10 L/d b Short chain fatty acids c Acids and salts d Average distance from the anus where mucosa samples were withdrawn e Shannon index designates the microbial diversity while high value shows high diversity f Flux along the colon, ml/d

14 Digestion 271

272

14 Digestion

More than 13,355 prokaryotic ribosomal RNA gene sequences from multiple colonic mucosal sites and feces of healthy subjects were identified. The majority of the bacterial sequences corresponded to uncultivated species and novel microorganisms. Significant intersubject variability and differences between stool and mucosa community composition were also discovered (Eckburg et al. 2005). The common consumption of whole-wheat bread supplies the highest content of the menu of the dietary fiber and the bound polyphenols. These 2 ingredients decompose in the colon and have a specific effect on colon activity. While most of the digestion activity of the wheat ingredients undergone in the upper gut, as for of most of the food ingredients, the dietary fiber decomposed at the lower gut. The mechanism that controls the microbiota concentration and their metabolic activity embedded in the bile secretion and the transporters absorption. The commensal metabolism of human and the microbiota has set up by the mechanism of the digestibility segregation. Although the gastrointestinal tract comprises a continuous space, the most sophisticated mechanism segregates the compartments. Whereas the passive bile absorption occurs along the jejunum and the upper ileum, the active absorption of bile acids restricted to the lower ileum and the colon. The ileum epithelium contains an efficient transport system for the active reclamation of the bile acids to enable the microbiota multiplication and reduce the water vicinity and to maintain the flux of 30 g/d of the enterohepatic cycle with a pool size of ~3 g and ~10 cycle/d (Dawson et al. 2009). Thus, a continuous decrease observed in the bile concentration of the gut with 10 mM at the distal jejunum and proximal ileum, 5.5 mM at the median ileum and 2 mM at the terminal ileum (Northfield and McColl 1973). With their high concentration in the small intestine, the bile acids enabled lipid absorption after emulsification (Sadeghpour et al. 2018). A lower concentration of 0.4 mM observed in the cecum (Hamilton et al. 2007) and a gradual decrease along the colon with the final fecal concentration of 0.06 mM. The gallbladder contains 300, the portal blood 0.03, and the peripheral plasma 0.005 mM with a considerable concentration ranges between individuals for each space. The dietary regime highly affects the individual concentration at the various segments (Bajor et al. 2010). The disappearance of the bile from the intestine lumen gives rise to the microbiota and enhances the water absorption where the main water and the electrolytes mass is absorbed. The small intestine must absorb massive quantities of water. A normal person size takes in roughly 1–2 liters of dietary fluid every day. On top of that, another 6–7 liters of fluid is received by the small intestine daily as secretions from salivary glands, stomach, pancreas, liver and the small intestine itself. By the time the ingesta enters the large intestine, approximately 80% of this fluid has been absorbed. The net movement of water across cell membranes always occurs by osmosis, and the fundamental concept needed to understand absorption in the small gut is that there is a tight coupling between water and solute absorption. Another way of saying this is that the absorption of water is dependent on the

14 Digestion

273

absorption of solutes. An increase of 105 fold in the microbiota count observed with at the distal jejunum to 108/mL at the terminal ileum. The metabolic activity of the microbiota in the proximal ileum is negligible because the digesta count is 106 fold lower than that of the colon. A second mechanism keeps a gradual proton concentration in the gut with the pH at the stomach 1.5–5, duodenum 5–7; jejunum 7–9, ileum 7–8, and the colon 5–7 (Walter and Ley 2010; Jandhyala et al. 2015). The high bile concentration in the jejunum and the proximal ileum inhibits the water transporters and preserves the fluidity along with these segments (Dawson and Oelkers 1995). For a simplification, the general averages collected from various sources (including the Wikipedia) presented without the statistical variability (Table 14.1). The gut segments have wide statistical ranges between individuals. The microbiota count refers to bacteria excluding the bacteriophages that habitat the bacteria at a rate of ~10 per bacterium. The gastrointestinal tract comprises >10 metabolic sites (Table 14.1) while the knowledge for the distinct metabolic activity of each site is limited. After the major bile acid content has pumped-up outside the distal ileum an accelerated multiplication initiated and enables the human organism to utilize efficiently the dietary fiber and the bound polyphenols that traveled intact along the upper gut. While detailed information has acquired for the microbiota variability of the upper gut segments with the high water content of the digesta. Inherent difficulties of the colon sampling supply us only limited information about the microbioa characterizations of the colon. The difficulty of the microbiota sampling has bypassed by the sampling of the microbiota population of the colon mucosa that might mirror the population of the colon lumen. The human gut microbiome is the subject of intense study due to its importance in health and disease prevention. The majority of these studies have based on the fecal analysis. However, little is known about how the microbial composition in fecal samples relates to the spatial distribution of microbial taxa along the gastrointestinal tract. The values presented in column 13 (Table  14.1) show the exact sites where the mucosa sampled for the microbiota characterization and the values in column 14 show the bacteria variability in the species population (Muinck et al. 2017). The decrease in the variability from the terminal ileum towards the ascending colon and then a marked increase towards the sigmoid colon suggests the continuous and the vigorous bacterial multiplication along with the colon segments. The bacteria population undergoes the most intensive transformations by eliminating and creating the new bacteria populations. Such revolutions suggesting a mechanism for efficient utilization of the ileum residues to extract the nutrients and probably in addition to induce the immune system (Fig. 14.1). GIT is controled mechanically along the tract by 3 sphincters (pyloric, ileocecal, and anal) and an additional one (Oddi sphincter) at the end of the common bilary duct that controls the flow of the bile and the pancreas outflow into the duodenum. The cecal appendix on the left and the lower cecum stays outside the GIT. Diverticuli are projects occur along the GIT but with the highest incidence in the sigmoid colon (Table 14.2).

274

14 Digestion

oral cavity

liver Pyloric sphincter

gall b.

right transverse Oddi (common duct) sphincter

Ileocecal sphincter

cecum Diverticuli

Anal sphincter Cecal appendix

Fig. 14.1  Schematic representation of the gastrointestinal tract (GIT). The GIT segments: 1. oral cavity; 2. esophagus; stomach segments: (3. fundus; 4. stomach body; 5. pyloric part; and 6. pyloric sphincter); 7. duodenum; 8. jejunum; 9. ileum; 10. terminal ileum; 11. ileocecal sphincter; 12. cecum; 13. ascending colon; 14. right transverse colon; 15. left transverse colon; 16. descending colon; 17. sigmoid colon; 18. rectum; 19. anus; and 20. anal sphincter. Located outside the gastrointestinal tract: liver, common bile duct, gall bladder, and pancreas (lays near the pyloric sphincter, not shown), cecal appendix, diverticula, and polyps (the last 2 projections located outside and inside the GIT, respectively), but mainly on the sigmoid colon

The Colon Deverticula and Polyps The incidence of diverticulosis and colorectal polyps increases as the population ages with the prevalence of >66% for subjects >70 y with the reported correlation between these 2 burdens and the lack of dietary fiber. With this respect, the colon diverticulosis and the polyp formation are tightly related to the intake of the whole wheat. Alterations involved in the development of the diverticular disease may also predispose the colonic mucosa for polyp formation. While there have been studies assessing the association between diverticulosis and colorectal polyps, the results have been conflicting. The relationship between the 2 burdens is difficult to study in view of the parallel increase in the frequency of both conditions. Despite sharing

The Colon Deverticula and Polyps

275

Table 14.2  The dynamics of the GIT flows

Oral cavity Esophagus Stomach

Pancreas Liver synthesis Gall bladder Small intestine

Colon

Dental plaque Saliva Fundus Body Pyloric antrum Pyloric sphincter

Count

cm

h 0.014

per mL

25 30

2.68

1011 109 104 5 ´ 103

H2 Oa

Bile flow b

mL/d

g/d

1000

1500

103

1000 Duodenum Jejunum Ileum Terminal ileum Cecoileal sphincter

650 22 250 350 ?

9 7

Ascending

23 58 33 49 20 4

Anus Anal sphincter

4.7 (4.33 ‒5.10 }

5 ´ 10 3 8 ´ 10 6 10 8 10 8

21.1 (23.9 ‒30.8 )

Appendix Cecum

Sigmoid Rectum

Feces

Transit time

1300

Transverse Descending

Whole gut

Length

2000

0.8 20‒30 c 20‒30

200 10 8

0.8 c

1011

28.9

F 30.5 M 27.2

9´ 1010

0.8 The human GIT equipped with 2 main vigorous enterohepatic cycles: 1. The bile cycle which influxes 20‒30 g of bile acids and bileacid salts into the duodenum. Along the jejunum and the ileum the bile absorbed and recycled through the portal vein into the liver. The liver synthesize only 0.8 g/d as the same outflux in the feces. 2. The water cycle which influxes orally 1‒2 L/d and excretes this volume in urine and feces, All the other influxes into the GIT are absorbed by the intestine and recycled into the portal vein.

Influx into the GIT Bile salts and bile acids c Flux along the colon The arrow on the right column designates a continuous decrease in the bile flux concentration a b

276

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common epidemiologic predisposing factors, the association between the burdens remains unclear and needs better clarification (Muhammad et al. 2014). The mechanism for how certain foods may reduce the risk of colon cancer or colon polyps is still unclear. Bioactive components in plant foods may induce antioxidative properties, thereby inhibiting carcinogenesis (Tantamango et al. 2011). Diverticulosis is a common digestive disease particularly found in the colon. It involves the formation of pouches (diverticula) on the outside of the colon. Diverticulitis results if one of these diverticula becomes inflamed.

The Diverticulosis Burden Terms Diverticulosis  A condition marked by small sacs or pouches in the walls of a hollow organ, such as the colon. These sacs can become inflamed and cause a condition called diverticulitis. Diverticulum(a)  A small pouch or sac that bulges out from the wall of a hollow organ, such as the colon. Diverticulitis  Inflammation of one or more pouches or sacs that bulge out from the wall of a hollow organ, such as the colon. Symptoms include muscle spasms and cramps in the abdomen (Fig. 14.2). Diverticulitis is out of the scope of the present discussion because this disturbance is not common and occurs rarely but with an increased risk. In the US from the year 1909 to 1975, fiber intake decreased by 28%, thereafter a dramatic increase in the prevalence of diverticular disease was observed. In a British study, a group of vegetarians on a high-fiber diet had a lower prevalence of diverticulosis than did nonvegetarians (12 vs. 33%). (Bhuket and Stollman 2016). In UK residents who consumed a refined, low-fiber Western diet, had stool transit time twice longer as

Fig. 14.2  On the left - the black holes show the openings of the diverticula; on the right - a sigmoid polyp (from the surgery of ER)

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well as stool weight significantly less than those of rural Ugandans eating a very high-fiber diet. In the European and US populations, diverticular disease arises mainly in the distal colon, with 90% of patients having sigmoid colon involvement and only approximately 15% having the right-sided disease. Colon diverticula mostly occur in the sigmoid segment at a prevalence of ~70% of all colon diverticula. Diverticula vary in diameter but typically are 3–10 mm in size. Giant diverticula, which are extremely rare, are defined as diverticula >4 cm in diameter; size up to 25  cm has reported. People who have colonic diverticulosis usually have several colonic diverticula (MSD manual). Colonic diverticula are the most common finding on colonoscopy. Almost all of these lesions result when colonic mucosa and submucosa herniate through the muscularis propria where the vasa recta penetrates. Colonic diverticula can be complicated by a spectrum of morbid and mortal diseases including diverticulitis, diverticular bleeding, and free rupture. Diverticular pathology is associated with a 5-fold increased risk of developing chronic gastrointestinal symptoms or a mood disorder and other morbidities. The diverticulosis prevalence lower in females vs males (incidence of 0.8 vs 1); increases with BMI (3 vs 1, for BMI of 23 vs BMI >30; and markedly increases with age (Peery et al. 2016). In a survey conducted in Rome subjects (n = 1090), a marked increase in the diverticulosis prevalence has observed with age (Fig. 14.3). At a higher age, >90, a lower incidence observed suggesting a negative relationship between diverticulosis incidence and survival (Fig. 14.3). A similar trend as that of the marked increase in the diverticula prevalence by age has also observed for the colon polyp occurrence by age. Such a trend has shown in the necropsy study conducted in Liverpool. A marked difference was observed in both burdens, while diverticula have the highest occurance in the sigmoid section, the polyp highest occurrence found in the colon (Williams et al. 1982). 70

Prevalence, %

60 50 40 30 20

30

40

50

60

70

80

90

Age Fig. 14.3  The prevalence of diverticulosis in a sample of Rome subjects (n = 1090), by age (Cecco et al. 2016)

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Because the intake of the dietary fiber has an alleviative effect on the occurrence of colon diverticula and polyps, the intake of the whole bread presumably decreases both burdens. In industrialized countries, diverticulosis is the most frequent disease affecting the colon that may lead to similar symptoms of colorectal cancer. It has been considered that diverticulosis and in particular, diverticulitis may have an association with subsequent development of colorectal cancer. Such possible associations have prompted guidelines to perform complete colonoscopy following the recovery from diverticulitis. In a study conducted in the Copenhagen area with 4500 subjects, diverticula were associated with a significant risk of having or subsequently developing a primary malignant disease (Hvolris et al. 2016). The whole-wheat bread presumably is also associated with the lower risk of diverticulosis and consequently, with the associated burdens. even no direct evidence is available. However, because a considerable intake of the whole-wheat supplies an adequate additive intake of the dietary fiber, the high intake of dietary fiber has shown to be associated with a lower relative risk of diverticulosis. In a study conducted with 48 k subjects of the general UK population, a lower incidence risk of diverticular disease of 0.59 observed in the higher quintile of fiber intake (>25g/d) vs the lower quentile (Crowe et al. 2011). The increase in the diverticula prevalence and the increase in the diverticula volume regularly raise the risk of diverticulitis. However, additional effects might be more imperative. The total surge of the digesta trapped in the diverticula markedly reduces the turnover rate of the digesta inside the diverticula lumen and increases the t1/2. Such an increase in the digesta t1/2 intensifies the microbiota activity on the bile acids that result in accelerated hydroxylation and other modifications of the bile acids and bile salts. The bile concentration and the derivatives types in the colon have a major role in the microbiota species, the microbiota count, water absorption with possible effects on constipation, other colon burdens, and the t1/2 of the whole colon digesta. The modified bile acids and the other bile acids are recycled from the colon into the liver and the gall bladder throughout the bile enterohepatic cycle. When the bile delivers into the duodenum through the common duct, the modified bile acids affect the entire gut digesta from the duodenum downside and the water absorption and concentration along the upper and the lower gut. The modified bile acids believed to acquire a higher cytotoxicity activity than the primary bile acids with a higher induction capacity on the colon diverticula and polyp prevalence and enlargement. Thus, at the end of the cascade the bile acids that had modified at the diverticula, affecting the marked changes in the microbiota population. Such an effect is particularly more intensified in the elderly acquired higher diverticula prevalence with a higher rate of constipation and possibly induction of other burdens. Because the modified bile acids are circulating in the peripheral blood, they might also induce malignancy in other organs. The intake of the whole-wheat bread might change all the cascade rates.

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With the very high prevalence of the colon diverticulosis in the Western population and in particular with the advanced age, the whole phenomenon seems to be most enigmatic with the most restricted information and in particular the biology of the development, expansion, and the interrationship between the diverticula content and the colon outflux (Cuomo et al. 2018). The diverticulum which extends outside the GIT and the small passage into the colon has presumably a long turnover time of its digesta with a very long-time activity of the microbiota on the bile acids. Marked changes have observed in most of the bile acids derivatives in constipated patients (Vijayvargiya et al. 2018; Wald 2019) with a particular increase in the hydroxylation of the bile acids, the polarity, and the cellular toxicity. Since the turnover time of the diverticular digesta content is much longer than that of the sigmoid feces flux, we may expect a higher rate of derivatization and the biliary types in the diverticula digesta with the higher possible effects. Marked changes have observed in most of the bile acids derivatives in constipated patients (Vijayvargiya et al. 2018; Wald 2019) with a particular increase in the hydroxylation of the bile acids, the polarity, and the cellular toxicity. Since the turnover time of the diverticular digesta content is much longer than that of the sigmoid feces flux, we may expect a higher rate of derivatization and the biliary types in the diverticula digesta with the higher possible effects.

The Digesta Flow Most of the edible food products in the gut are “complex fluids” with an internal microstructure, leading to rich and diverse flow behavior even for rather “simple” and well-controlled boundary conditions. Flows inside the gut introduce additional levels of complexity because of the strongly asymmetric, time-varying boundary conditions in these flows and the progressively changing structure and rheology of a food bolus exposed to the body temperature, the effect of the saliva and the “mechanical treatment” during its “journey” through the gut (Engmann and Burbidge 2013). The saliva is a critical part of bolus formation. Although it is 99% water, the remaining components are critical. The major soluble component is the mucins, which are mucopolysaccharides, and complex carbohydrates attached to a protein backbone. The mucins control the viscosity and the surface tension, making the bolus bind together, and act as a lubricant, assisting with swallowing and passage through the gut. The mucins have important viscosity and shear-thinning behaviors, conferred by their structure, which facilitates cohesion of the bolus but also assists in lubrication during the transport, and thought that getting the right bolus rheology is an important factor in enabling swallowing (Boland 2016). The gut begins at the mouth; continuous through the esophagus, stomach, and the small and large intestines; and ends at the anus with a total length of 8–9 m. The goal of oral digestion is to produce a mass of the chewed food known as a bolus. The bolus must have a sufficiently small particle size and adequately lubricated with the saliva. As the bolus passes through the lower esophageal sphincter into the stomach, the

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proximal stomach relaxes, allowing the ingested bolus to layer on top of the previously swallowed boluses. As the boluses enter the stomach, they will “stack up” in the curvature of the stomach according to the time they ingested. Layers will begin to form according to the density and the solids content. During the gastric digestion, the boluses reduced in size while being chemically broken down due to the acidic and the enzymatic conditions. The rate at which the food disintegrates will control the rate at which it emptied from the stomach and move to the intestines where nutrients absorbed. The stomach is primarily comprised of the cardia (the upper compartment), the fundus, and the antrum. The cardia filled with mucin-secreting cells. The fundus lined with the mucosa forming thick folds, known as rugae, where the parietal cells secrete HCl and the chief cells secrete the pepsinogen, an active precursor that converted into the proteolytic enzyme pepsin upon the contact with the acid. The parietal cell secretion provides a substantial volume flow against an enormous electrochemical gradient. The energy cost for secreting is ~10 kcal/mol, the highest for any biological ion transport process, requiring one ATP for the one-for-­ one H for K exchange (principally because of the large pH gradient) from the cell to the lumen, of >106). To secrete 300 ml of 150 mM HCl/h (the typical stimulated rate), ~108 pump cells are required. The unique parietal cells consist of the highest density of mitochondria with 40% of the total cell volume. The basal output of HCl is below 11 mmol/h increasing to 10–63 mmol/h with meals. The acid solution contains 160 mmol of HCl per liter resulting in a pH of 0.8. At this pH, the [H+] is about three million times that of the arterial blood and this high concentration of protons is responsible for the effects of gastric acid while ~8 I/d of fluid is secreted into the human intestinal tract. Since water cannot be actively secreted, the driving force for fluid flux is the osmotic gradient between the lumen of the intestine and the mucosa. Among other secretions, the parietal cells secret the intrinsic factor (Forte 2010; Kopic et al. 2009; Berend et al. 2012). The proximal stomach acts as the food reservoir while the distal stomach is the main location of the physical breakdown of the food. In the distal stomach antral contraction waves or the peristaltic contractions of the stomach wall, act to crush and grind food particles until they pass through the pyloric sphincter into the small intestine that extends from the pyloric sphincter to the ileocecal junction and is 6–7  m long. The jejunum, the second intestinal section after the duodenum, is ~2.5  m and extends from the duodenum to the ileum. The majority of nutrient absorption occurs in the jejunum. The ileum comprises the remaining ~3.5 m of the small intestine. The chyme transported through the intestines by segmentation and peristaltic muscle contractions. Segmentation contractions aid in the mixing of the chyme, allowing for a large amount of material to contact the intestinal walls, which helps with nutrient absorption. The peristaltic contractions result in a large forward movement, propelling the chyme at a rate of 2–25  cm/sec. The large intestine extends from the ileocecal junction to the anal canal and is ~1.5 m. The stomach secretes an average of 2–3  L/d of the gastric fluid comprised of mucus, acid, enzymes, and intrinsic factor. Foveolar cells located in the superficial mucosal compartment of the stomach secrete mucus and bicarbonate. The gastric acid secretion

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is 10–30 mEq H+/h. Parietal cells also secrete intrinsic factor, a protein that binds to vitamin B12 and allows for its absorption in the terminal ileum. Chief or zymogenic, cells secrete the inactive precursor peptide pepsinogen, which converted into the active proteolytic enzyme pepsin upon contact with acid by the removal of a peptide with 9 amino acids. Chief cells also secrete gastric lipase, which responsible for 10–30% of triglyceride hydrolysis. The digesta flows along the small intestine by the antral contraction waves, emitted by the stomach with a speed of 9–18 cm/ min and a frequency of 2.6–3 waves/min (Bornhorst and Singh 2014; Bornhorst and Singh 2012). Solid foods breakdown during the gastric digestion due to the mechanical forces and the enzymatic and acidic environment. Functionally, the stomach contains the proximal region that acts as a reservoir, containing particles until they can move into the distal region. In the distal stomach, the physical breakdown occurs by the peristaltic muscular contractions. The physical and chemical properties of gastric chyme are not homogeneous throughout the stomach (Shani-Levi et al. 2017). The main function of the small intestine is digestion and absorption of the nutrients, mostly occurring in the upper portion of the small intestine (duodenum and jejunum). To fulfill this role, intestinal enzymes, bile, and various electrolytes (particularly Na, Cl, Ca and K) required. The large absorptive area of the intestine enables the high intestinal absorption rate. Its inner wall, or mucosa, folded, with each fold covered with villi, which in turn lined with microvilli. The chyme that reaches the small intestine undergoes a process of longitudinal mixing and breaking down by peristalsis and segmentation. The extent of the chyme mixing and propelling along the intestinal tract determined by its rheological properties (e.g. viscosity). These properties, therefore, affect the nutrient release and absorption. The digesta is a suspension of particulates, the composition of which changes as they progressively transit along the gut. In the ileum, the presence of the nutrients, particularly the lipids, activates the ileum brake, a series of negative-feedback mechanisms that seem to link to reduced food intake by inhibiting the gastric emptying and the intestinal motility. This process results in ‘optimizing’ the digestion of the nutrients by slowing down the physiological activity of the gut motility in the upper parts of the gut, making the main site of the absorption more proximal. As the digestion of lipids is a highly efficient process, the majority of dietary lipids hydrolyzed and absorbed in the small intestine. The plant food macronutrients and micronutrients that not absorbed in the small intestine reach the colon, which is the main site of the water and the electrolyte uptake, and together with encapsulating fiber are potential substrates for the microbiota. Short-chain fatty acids, notably acetic, propionic, and butyric acids, produced in the colon by the microbiota fermentation of the dietary carbohydrates that have escaped the digestion in the upper part of the gut. The structure and the properties of the cell wall play an important role in regulating the release/ availability of the micronutrients and the macronutrients from plants foods during the mastication and the digestion. A significant proportion of the cell walls may remain intact even after the mastication and the other phases of the digestion process and, as a result, may decrease the rate and extent of the digestion and the

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postprandial metabolic response. The cell walls remain resistant to the digestion in the upper gut of because they are not attacked by the eukaryotic enzyme secretions (released by the human cells) that unable to hydrolyze polysaccharide components of the plant cell walls. The digestive enzymes acting on the available carbohydrates can only hydrolyze the α-1,4- and α-1,6-glucan linkages of the starch. The structure and the behavior of the individual cell wall polysaccharides and the macroproperties of the cell wall matrix have a significant bearing on how plant foods disassemble and release nutrients. The capacity of cell walls to limit digestibility is, therefore, dependent on the extent to which cellular integrity preserved during the processing, the mastication, and the transit, which, in turn, vary between the plant species. The nutrients released from plant tissues in the oral cavity and the subsequent sites of the gut may trigger neuronal and humoral signals that have an impact on the digestion such as gastric emptying, peristaltic contractions, and the ileum brake (Grundy et al. 2016).

The Colon Activity The colon microbiota sustained by the dietary-ingredients and by the endogenous components with dietary-fiber. For a typical adult person the following flows estimated, (g/d): non-fermentable dietary-fiber 10–25; fermentable dietary-fibers 5–35: resistant starch 5–35, oligosaccharides (fructo-, gluco-oligosaccharides and inulin) 2–8, and monosaccharides (sugars, sugar alcohols) 2–5; dietary-protein trapped by dietary-fiber 1–12; and the endogenous flows of, intestinal mucins 3–5; endogenous secretory proteins (pancreatic and intestinal enzymes) 4–8; non-protein nitrogen (such as urea) 0.5; and desquamated epithelial cells, 30–50. Approximately 1–5% of circulating bile salt reaches the colon, where it metabolized to secondary bile acids (Egert et al. 2006). Protein availability for colon fermentation lays in the range of 5–20 g/d (Guarner and Malagelada 2003). Monosaccharides decomposed from carbohydrate polymers are converted in microbiota cells to short-chain fatty acids (SCFA) with molar ratios of (%): acetate 70, pyruvate 20 and butyrate 10. In humans maintained on a European diet, 50–60 g/d of carbohydrate are typically fermented, yielding 0.5–0.6 mol of SCFA, with a total energy value of 140–180 kcal. The butyric acid production is most vital for the normal physiology of the colonic epithelium (colonocytes), derives 60–70% of its energy needs from butyrate. Butyric acid affects epithelial proliferation and differentiation and acts against colon cancer (Orchel et al. 2005). The production of butyric acid is one reason why the adequate intake of dietary fiber reduces the incidence of colorectal cancer (Hooper et al. 2002). The number of the immune cells in the epithelial layer of the colon greater in cecal crypts than in the crypts of the distal colon. In the rat, ingestion of dietary fiber significantly promoted the accumulation of the immune cells into the cecal epithelium. The immune cells in the epithelial layer are mainly concentrated at the lower

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quarter height of the cecal crypt as well as the distal colon crypt. The number of immune cells in the colon correlated with the concentrations of SCFA (2–5 carbons). The butyric and the acetic acid concentration in the colon have a high correlation with the increased number of the immune cell while the isovaleric and valeric acids have an opposite effect (Ishizuka et al. 2004). In a wide-range evaluation of the population groups, the incidence of colon cancer was steadily increased with the decrease in stool weight (Cummings et al. 2004). Dietary-fiber is well known by its effect on the colon flatulence while some food items, containing some types of the dietary-fiber, are causing considering inconvenience. The feeding of young male rates with the whole-wheat bread in a comparison to the bread baked from the refined flour showed a higher cecal concentration of the total SCFA and in particular butyric acid, a higher excretion of fecal bile acids, total steroids and cholesterol and lower plasma and liver concentrations of cholesterol, and triglycerides (Adam et al. 2003). The transportation of the phenolic compounds to the colon is a major physiological function of the dietary fiber. Some half of the dietary phenolic compounds transported to the colon by the dietary fiber. When bounded to the dietary fiber, the labile phenolic compounds protected against decomposition along the passage through the gut. The anthocyanins are unstable at the neutral pH of the small intestine, which contributes to their very low bioavailability in vivo.

Digestion of the Phenolic Compounds The dietary fiber and the phenolic compounds bounded by the hydrogen bonding, by the electrostatic interactions, and by the hydrophobic interactions. The amount of phenolic compounds that bounded to the dietary fiber depends on their types. Since the absorption is a surface phenomenon, the amount of the phenolic compounds bound would also depend on the total dietary-fiber surface and it would inversely proportional to the dietary fiber particle size. Since most of the dietary fiber ingested as cell walls, the interaction between the phenolic compounds and the plant cell walls is of particular importance. The physiological implications of the interaction between the dietary fiber and the phenol compounds modulate the bioavailability of the phenolic compounds. When absorbed to the dietary fiber, the polyphenols will escape absorption in the small intestine but can be released upon fermentation of the carrier dietary fiber in the colon and absorbed therein as a such or prior modification (Capuano 2017).

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The Bile Acids The classical role of the bile acids considered as the essential ingredient in the lipid decomposition and the absorption by the intestine. The less known activities are the organization of the movement of the fluids, the control of the microbiota activity along the intestine and as the chemical signaling compounds. At the proximal upper small intestine, the bile acids stimulate water secretion into the gut lumen at the total rate of ~12 L/d. The high concentration of the bile acids in the small intestine inhibits water absorption in the small intestine. At the upper gut, the bile acids prevent almost completely the decomposition of the sugars, fatty acids, and the amino acids by the microbiota activity (with ~109 fold lower microbiota count in the small intestine than in the colon) and thus enable the efficient digestion and absorption of the major mass of the nutrients by the eukaryotic enzyme. The bile acids act as signaling molecules to regulate glucose homeostasis, lipid metabolism, and energy expenditure. Also, the bile acids serve as signaling molecules with metabolic effects that extend beyond their control of the hepatobiliary and intestinal function. The bile acids synthesized in the liver, transported into the gallbladder to form the bile, and then downstream to the duodenum and the lower gut segments. Some of the bile acids, conjugated with the taurine or the glycine, and sodium and potassium, become the bile salts. In the colon, some part of the bile-acids and salts hydroxylated by the microbiota into the secondary bile compounds with much higher polarity. The bile acids have a major role in the gut with many control activities. Some of the control activities are: segregation of the water vicinity in the gut segments; segregation of the microbiota count and activity in the gut segments; enable lipid decomposition and absorption (including the fat-soluble vitamins); hormonal and signaling; and glucose metabolism. Understanding of the physiology and the metabolism of the bile acids and the control mechanisms are most important to study the specific effects of the whole-wheat on human physiology because of the major role of the wholewheat on the fermentation in the colon. At the terminal part of the small intestine, the main mass of the bile acids absorbed and recycles by the portal blood to the liver to maintain the enterohepatic circulation (at a rate of ~10  cycles/d). Such a circulation enables water absorption, and enhancing the microbiota multiplication (presumably at the highest known rate in nature) to promote the intensive activity of the colon microbiota metabolism. The rest of the bile acids either absorbed at the distal colon (and recycles by the portal blood into the liver) or excreted in the feces. Thus, the recycling machinery of the bile acids acts as the critical control engine. This control engine

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facilitates the normal food decomposition in the gut (Romański 2008; Dietschy 1968; Dawson et al. 2009; Kuipers et al. 2014; Molinaro et al. 2018). The bile acids pathways are the most important controls of the gut activities. While the bile recycling machinery highly affects the colon activity and the colon has the most important role in the whole-wheat decomposition of the dietary fiber and the bound phenols, particular attention is paid for the bile acid machinery even the direct relationships between the bile activity and the whole-wheat decomposition has not well documented. The bile acids exert a direct effect on the gut bacteria with a negative impact on membrane integrity and exert DNA damage. The extent of the cell damage related to the hydrophobicity and the structure of bile acids. Gram-negative more resistant to bile acids than Gram-positive bacteria. The resistance, tolerance, and susceptibility are strain-specific. Thus the bile acids have a marked effect not only on the bacteria count but have a major effect on the species composition and consequently on the metabolic pathways (Staley et al. 2017). The bile acids are steroid acids synthesized from the cholesterol in the liver. Following their synthesis, bile acids secreted along with other biliary constituents into the upper gut. After functioning in the proximal intestine to promote the nutrient digestion and absorption, the bile acids travel down to the terminal ileum for their main absorption. The bile acids then carried in the portal circulation back to the liver for uptake and re-secretion into the bile while ~95% of the bile acids secreted into the small intestine reclaimed. Those bile acids that escape the absorption pass into the colon and mainly eliminated in the feces. Part of the bile acid flux undergone hydroxylation, absorbed by the colonocyte and recycled into the portal bloodstream. The bile-acid transportation enabled by the specialized membrane transporters expressed on the apical and the basolateral membranes of the hepatocyte and the ileum enterocyte. The uptake of the bile by the ileum enterocytes are important for the gut-liver signaling and the regulation of the bile acid synthesis. The bile acid systemic circulation regulated in part by an efficient enterohepatic circulation that functions to conserve and channel the bile acids pool within the intestinal and the hepatobiliary compartments. The changes in the hepatobiliary and the intestinal bile acid transport can alter the composition, the size, and the distribution of the bile acid pool. These alterations, in turn, can have significant effects on the bile acid signaling and their downstream metabolic targets (Ferrebee and Dawson 2015). The bladder bile composed of 85% water. The remaining is a complex mixture of bile salts (67%), phospholipids (22%), and cholesterol (4%) together with electrolytes, minerals, and minor levels of proteins, plus bilirubin and the biliverdin pigments, which give it a yellow-green or even orange-blue color (Sipka and Bruckner 2014). The bile acids and the bile salts present in all gut segments from the duodenum down to the anus. Those that escape the absorption at the terminal ileum pass into the colon and considerably affect the gut metabolism. The bile acid uptake by the ileal enterocyte is important for the gut-liver signaling and the regulation of the bile acid synthesis. The bile acids viewed increasingly as metabolic regulators of the intestinal motility, the water content, the bacterial growth, the inflammation, the

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liver regeneration, the hepato-carcinogenesis, the absorption of the dietary lipids and the fat-soluble vitamins, the impairing cholesterol crystallization and the ­gallstone formation (Ferrebee and Dawson 2015; Vallim et al. 2013). In human, the bile acid pool contains ~2–4 g with a cycling of bile acids/salts for the liver/intestine 6–10 cycles/d and transports 20–40 g bile acids while 0.2–0.6 g/d excreted in the feces, an amount that must replenish by the de novo synthesis from the cholesterol. The hepatic recovery of the bile acids from the portal vein (with a concentration of 10–80 mM) is incomplete, thus accounting for the presence of the low levels of the bile acids (~2–10 mM) in the peripheral circulation. The concentrations of the individual bile acids in the systemic blood of the portal vein vary with the food consumption, as the resorption of the bile acids is greatest in the postprandial period. The relatively high concentrations of the bile acids in the tissues involved in the enterohepatic circulation (liver, bile ducts, gallbladder, and intestine), is sufficient to activate the receptors in these tissues (Vallim et al. 2013). The bacterial activity in the colon bio-transformed ∼5% of the bile. The enzymes involved in various transformations have characterized with greater diversity in the isoforms of these enzymes. Thus, the functional roles played by the bile acid transforming the gut microbiota and the distribution of the resulting secondary bile acids, in the bile acid pool, may be profoundly affected by the microbial community structure and function. The composition of the bile acid pool mediated by the bacterial metabolism in the intestinal tract and intrinsically linked to the host physiology. This occurs via a variety of regulatory processes, variation in toxicity among the bile acids, and the microbial ecology of the gut. The bile salts are formed in the main 4 different forms, namely, cholic, deoxycholic, chenodeoxycholic, and lithocholic (Fig. 14.4). These acids, in turn, can interact and combine with glycine or taurine forming complex acids and salts (Fig.  14.5) (Malik 2016). The hydrophilicity of the bile acid pool associated with the disease states. Reduced bile acid levels in the gut-associated with bacterial overgrowth and inflammation. The diet, antibiotic therapy, and the disease states affect the balance of the microbiome-bile acid pool. In the colon, the bile acids bio-transformed into secondary bile acids by the 7α-dehydroxylation activity and either reabsorbed via the portal circulation or a minor amount excreted in the stool. The 7α-dehydroxylation reaction has described as the most quantitatively important process performed by the colonic microflora, resulting in the formation of the secondary bile acids that predominantly found in the feces. However, only ~0.0001% of the colonic bacteria can perform this reaction. The bile acids can exert direct influences, both positive and negative, on the gut bacteria with an overall negative impact on the membrane integrity, likely due to an increase in membrane permeability leading to the cell death. The extent of the cell damage related to the hydrophobicity and the structure of the bile acids, where more hydrophobic bile acids and those with the 2 rather than the 3 hydroxy groups are more detrimental to the membrane integrity than other bile acids. The bile acids also damage DNA and promote the increases in the enzymes involved in the DNA repair. The bile acids may also cause oxidative and

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Fig. 14.4  The 4 main forms of the bile acids (a) Cholic acid (cholate): Cholic acid is a major primary bile acid produced in the liver and is usually conjugated with glycine or taurine. It facilitates fat absorption and cholesterol excretion. Bile acids are steroid acids found predominantly in the bile of mammals. The distinction between different bile acids is a minute and depends only on the presence or absence of hydroxyl groups on positions 3, 7, and 12. Bile acids are physiological detergents that facilitate excretion, absorption, and transport of fats and sterols in the intestine and liver. Bile acids are also steroidal amphipathic molecules derived from the catabolism of cholesterol. They modulate bile flow and lipid secretion, are essential for the absorption of dietary fats and vitamins and have been implicated in the regulation of all the key enzymes involved in cholesterol homeostasis. Bile acids recirculate through the liver, bile ducts, small intestine, and portal vein to form an enterohepatic circuit. They exist as anions at physiological pH and consequently require a carrier for transport across the membranes of the enterohepatic tissues. The unique detergent properties of bile acids are essential for the digestion and intestinal absorption of hydrophobic nutrients. Bile acids have potent toxic properties and there are a plethora of mechanisms to limit their accumulation in blood and tissues. Among the primary bile acids, cholic acid is considered to be the least hepatotoxic while deoxycholic acid is the most hepatoxic (HMDB). (b) Deoxycholic acid: Deoxycholic acid is a secondary bile acid produced in the liver and is usually conjugated with glycine or taurine. (c) Chenodeoxycholic acid. (d) Lithocholic acid, also known as 3α-hydroxy-5βcholan-24-oic acid or LCA, is a secondary bile acid. It is formed from chenodeoxycholate by bacterial action

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Fig. 14.4 (continued)

pH stress and may chelate important cellular ions, such as calcium. The bile resistance, tolerance, and susceptibility are strain-specific (Ridlon et al. 2014). The microbiota concentration of the upper small intestine is ~104/mL, while the human colon contains the highest known concentration in nature of 1011/mL. The bacteria that inhabiting our upper intestinal tract must have a peculiar mechanism of intrinsic resistance to cope with the high concentration of the bile acids. However, the terminal ileum segment contains 107–108/mL, much higher than the rest of the small intestine but still lower than the colon concentration. Thus, under normal physiological conditions, our gut holds a bile salt concentration gradient ranging from more than 40 mM to less than 1 mM – equivalent to a range between 2% and 0.05% – which responsible, among other factors, for shaping the microbial community profile found in our gut and the differences in water concentration. While ~12  L/d water enters the small intestine, in comparison to a very small amount excreted in the stool.

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Fig. 14.5  The main 2 amino acids with a high tendency to form bile salts: glycine and taurine

Thus, the general collected ranges the bile acid and salts (mM): liver 5; gallbladder 30 (10–50); jejunum 12 (4–20); cecum 1; colon 1; portal blood 0.1; and peripheral blood 0.012 (0.005–0.02). Apart from its normal physiological function, the bile is highly toxic for those microorganisms that un-adapted to the intestinal conditions. The enteric bacteria, including lactobacilli and bifidobacteria, must have evolved specific defense mechanisms to resist the deleterious action caused by these compounds. The strong lipophilic nature of the steroid ring makes the cell membrane the main target of these molecules, in which they disturb the lipid packaging and disrupt the proton motive force, causing cell death. Since the unconjugated forms are weak acids, they can passively diffuse into the cell and, once inside, they dissociated producing an acidification of the cytoplasm. Other side effects induced by the bile have, including the induction of the oxidative stress and DNA repair mechanisms, the alterations of the sugar metabolism, and the misfolded proteins (Boland 2016; Ruiz et al. 2013; Moghimipour et al. 2015; Bajor et al. 2010). The microbiota delivered into the colon with a transit time of ~50 h and a total capacity of ~1000 mL. With the 1011/mL cells, the total microbiota cell length in the colon is ~1014 μm or ~105 km (with a bacterium length of ~1 μm) produced within 30  h (transit time). Thus, total reproduction length is ~100,000  km/30  h or 3300 km/h, as for the high-speed jet fighter velocity. Such an assumed calculation of the microbiota production does not consider the microbiota that deceased along the colon and the production of other microbiota. The tremendous population of the microbiota that ferments the dietary fiber, extracts some energy capacity, and more importantly induce the immune system in the colon viscidity. The bile acids are the amphipathic products of cholesterol

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metabolism in the vertebrates. They play irreplaceable roles in solubilizing lipids, eliminating catabolites such as the bilirubin. The physiological role of the bile acids as important metabolic signaling molecules that modulate the lipid, glucose, and energy metabolism has also gained a lot of recognition. Because of the e­ nterohepatic circulation is driven by a series of membrane transporters, the composition of the human bile acids pool entangled with a complex host-gut microbial co-­metabolism. The human bile acids are C24 molecules comprised of a C19 cyclopentanophenanthrene (a steroid) nucleus and a carboxylate side chain (Lan et al. 2016). The bile acid pool size and composition inherently linked with the microbial community presence, and presumably, the composition. The bile acids reabsorbed in the terminal ileum, primarily through active transport by the apical sodium-dependent bile salt transporter or by the ileal bile acid transporter (Staley et al. 2017).

The Bile Acids and the Whole-Wheat Interaction With the ~half of the total dietary fiber intake supplied by the whole-wheat bread intake it presumably affects the colon activity more than any other food item. The understanding of the interaction between the bile acids and the bread is a most important issue because of the highest rate of the bread digesta influxes into the colon and the major control of the bile on the gut activities. However, the information for such an interaction is quite restricted. The extended effects of the bile acids and the alterations in the bile acids on the morbidities and the other disorders should pay our attention to the interaction with the wheat digesta. The alterations to the gut microbiota that influence the bile acid metabolism associated with the metabolic disease, obesity, diarrhea, inflammatory bowel disease (IBD), Clostridium difficile infection, colorectal cancer, and hepatocellular carcinoma. The bile acids are important in maintaining the physiological homeostasis through the host signaling events. Even only a minor part of the bile acid flux reaches the colon, the colon microbiota have a central role in bile acid metabolism. The bile acids have emerged as major effectors in the microbe-host signaling events that influence the host energy metabolism, weight gain, inflammation, and the circadian rhythm. During aging, both changes occur in the microbiota and the bile acid profiles. The bile acid profiles in aging, cholesterol accumulation and altered cholesterol metabolism are the biochemical features of the aging process (Joyce and Gahan 2016). The effects of whole-wheat intake in the decrease in the incidence of colon cancer are the most interesting issue. The butyrate and the production of the other short-­ chained fatty acids lower the colonic pH and the cellular proliferation and differentiation. This results in the inhibition of the bacterial transformation of the primary into the secondary bile acids and in a decreased solubility of these acids. The secondary bile acids are cytotoxic to the colonic cells, subsequently resulting in increased cell proliferation. The increased cell proliferation associated with a higher susceptibility to the development of colonic cancer.

The Bile Acids and the Whole-Wheat Interaction

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The gel-forming types of fiber could bind bile acids and increase the colonic bile acid load. Thus, the fiber derived from the vegetables, fruit, or cereals can have a different protective effect on colon cancer formation. It is still unclear to what extent the difference in the fermentability of the fiber types contributes to these differences. An unhealthy dietary pattern regarded to be a significant health risk factor, limiting the production of the short-chain fatty acids (SCFAs) and giving rise to the high luminal concentrations of putative risk factors (secondary bile acids, protein degradation products). The diets with a higher dietary fiber content stimulate the SCFA production and reduce the exposure of the colonic epithelium to potentially toxic compounds, which have shown to oppose the induction of DNA strand breaks due to the high protein concentrations (Erik and Knudsen 2018). The bile acids and their salts are the main control mechanism of our gut activity in addition to the traditional notion of their main role in lipid digestion. The sophisticated mechanisms of the bile acids absorption control the digestion by some mechanisms: (a) The water concentration along the gut varies remarkably with ~12  L/d water influx into the upper gut segments and the tinny amount excreted in the feces; a high water concentration in the upper gut and a low at the lower gut. (b) As well, the microbiota count varies tremendously with ~104 counts/mL along with the upper gut segments and a tremendous count of 1011/mL observed in the colon. (c) The most accelerated multiplication rate of the microbiota at the terminal ileum (presumably the highest known in nature). A continuously accelerated multiplication present along with the colon segments. The bile- acids/salts in the colon that escaped the absorption at the upper gut undergo intensive hydroxylation by the microbiota. Such a hydroxylation increases the bile acids polarity. The high polarity of the bile acids has a marked effect on the development of diverticula in the colon (and consequently colon malignancy). The adsorption capacity of a fiber relates to its potential to bind food substances such as water or minerals and the endogenic substrates such as bile acids in the colon. The interactions of a particular soluble dietary fiber, such as β-glucan, with the bile acids, contribute to their cholesterol-lowering effect. The dietary fiber interacts with water in some ways, including enclosure and hydrogen bonding. The water-holding capacity of the dietary fiber strongly depends not only on its chemical composition but also on the physical characteristics such as particle size. The colonic microbiota can produce many potential carcinogens, such as secondary bile acids, but also protective metabolites such as SCFAs possess anti-inflammatory effects, inhibit cancer cell proliferation, and selectively induce the apoptosis in the colorectal cells (Verspreet et al. 2016).

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The dietary fiber reduces the passage times using water binding and fecal bulking effects leading to a dilution of the harmful components. The SCFA butyrate utilized as an energy source in non-transformed cells, whereas in the tumor cells, the butyrate reduces the survival by inducing the apoptosis and inhibiting proliferation. The butyrate also plays a role in the induction of glutathione S-transferases, which involved in the detoxification of many carcinogens (Schlörmann et al. 2012). The factors that affect the concentration of the secondary bile acids in the aqueous phase of the stool may have a greater impact on the colon carcinogenesis than those that only modify the total fecal bile acid concentration (Colon et al. 2003). The total fecal bile acid concentrations were higher with the fiber-free diet than with the 30 g wheat bran, mixed vegetable fiber, and sugar-beet fiber (Lampe et al. 1991). The high amount of the fiber supplement of the wheat bran given for 9 months associated with reductions in both the total and the secondary fecal bile acid concentrations and excretion rates in patients with resected colon adenomas. The observational data from epidemiologic studies suggest a causal association between the high concentrations of the bile acids in the stool and colorectal cancer (Bianchi et al. 2010). The concentration of the total and the secondary bile acids in the serum of men with adenomas was significantly higher than that in the serum of the control subjects (Alberts et al. 1996). The binding of the bile acids to the dietary fiber would make the bile acids unavailable as surfactants in the small intestine thus disturbing lipid emulsification, the formation of the mixed micelles, and the complete digestion of the lipids and their absorption. This may result in lower levels of circulating triglycerides but also to a reduced the bioavailability of the lipophilic nutrients (Capuano 2017). One interesting activity of the whole-wheat is the decrease in the cholesterol pool. In addition to diminishing cholesterol incorporation into micelles, the phenols hinder cholesterol absorption by decreasing its solubility. For example, the phenols can form insoluble precipitates with the cholesterol oxidation products and consequently impede their uptake (Domínguez-Avila et al. 2017).

The Bread Digestion The starch is the most abundant nutrient in the global diet for the people majority, providing the main energy source to the rapidly growing population. Due to the hydro-thermal treatments commonly used, the starch granular structure disintegrates, leading to rapid digestion of the starch and thus a swift absorption of the glucose in the small intestine (Svihus and Hervik 2016). Of the convenience foods examined, the ileum starch digestibility was greatest for the cereal foods and chips and least for the beans. This difference accords with the view that the legume starch much less digestible than the cereal starch. The starch amylose content seems to play an important role in determining the resistant starch content of foods. Before digestion, the starch granules had an irregular appearance with cracked and rough surfaces. In contrast, starches recovered from the ileal effluent were smaller and smoother. There was a marked reduction in the granule size from 8 to 40 μm before

The Terminal Ileum Is the Main Site Control of the Gut Activity

293

digestion to ~7  μm at the proximal ileum. The largest of these was composed p­ rincipally of the amylopectin, the highly branched polymer. The medium fraction was mostly higher molecular weight amylose while the smallest fraction was the lower- molecular weight amylose. The amylose is a smaller polymer than the amylopectin with a less branched structure and the amylose molecules have a high tendency to aggregate and crystallize during the retrogradation compared with the other starch fractions (Zhou et al. 2010). The term digestion confined to the food disintegration at the upper gut that operated by the eukaryotic enzymes while the term fermentation confined to the lower gut that operated by prokaryotic enzymes. The bile enterohepatic cycle preserves the high bile concentration in the duodenum, jejunum, and ileum with a drastic reduction in the terminal ileum and a further continuous reduction in the colon. Concomitantly, because of the control of the bile on the water absorption, the water content of the digesta in the jejunum and the ileum is very high and reduces dramatically from the proximal ileum towards the proximal colon. The gut segments with the high bile concentration contain very low microbiota count and with the reduction of the bile concentration, the count increases immensely. The majority of the bread decomposition and absorption occur in the upper gut and only a minor part takes place in the colon. However, as a main supply of the dietary fiber, the whole-wheat bread has a major role in the immunologic activity of the colon but only with a piece of limited gathered information. As the main staple food, the kinetics of the glucose decomposition and the absorption observed in different glycemic indices has the main role in the wellbeing of the diabetic people. High differences in the sugar composition, the glucose accumulation and the glycemic curves have noticed between varieties and the wheat cultivars as shown in human and in animal experimentations (Alamo et  al. 2009; Rosicka-Kaczmarek et al. 2013; Zhou et al. 2014; Widodo et al. 2015; Štěrbová et al. 2016). With the accelerated proliferation of the diabetes disease and the elevated glucose concentrations in many people worldwide and with the consideration of the high variability in the wheat cultivars in a respect to their glycemic indexes, a wide room opened for the wheat breeders to introduce wheat varieties with moderate and low glycemic indexes. Such varieties might have brand names instead of the commodities.

 he Terminal Ileum Is the Main Site Control of the Gut T Activity The major role of the bile acids in the bread digestion requires a particular description of the bile control. The effect of the bile concentration on the digestion of the dietary fiber acts either by direct activity or by the bile absorption before the colon.

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Such an efficient absorption enabling the unique microbiota activity in the colon. The dietary fiber intake of the whole wheat bread that comprises ~ a half of the total dietary fiber intake, affects the bile absorptin, delivery, conjugation, and hydroxylation and thus has a remarkable effect on the bile enterohepatic cycle. The terminal ileum that also termed the distal ileum, starts somewhere at the lower part of the ileum and ends at the ileocecal valve (a sphincter muscle valve that separates the ileum and the colon). This terminal ileal segment has the most important role in the control of the gut activity as it absorbed most of the residual bile concentration and leaves only small bile concentration in the digesta flux that transferred into the colon. The bile acids are passively absorbed along the ileal tract with a consequent decrease in the water concentration. In the upper gut, the high bile concentrations inhibit the water transportes and thus keep the watery environment of the digesta and enabling the digestion and the absorption of the main dietary mass. Such an absorption happens by the efficient bile transporters. The epithelial cells of this segment widely express the apical sodium-dependent bile acid transporter (ASBT). In contrary to the other bile transporters, involved in the enterohepatic cycle, that can transport non-bile acid molecules, the ASBT transport only bile acids and has a greater affinity for those that are conjugated (to taurine or glycine) over those that are not. Since no data has acquired for the length of this terminal ileum that contains ASBT, a gradual increase in the ASBT concentration along the distal ileum might be suggested. The massive bile reabsorption changes thoroughly the whole gut activity by stopping the inhibitory effect of the bile on water transporters and markedly increase in the absorption of the gut water flux. Consequently, the reduction in the bile concentration promotes a vigorous rate of microbiota production (mostly bacteria). The residual low bile flux into the colon at a rate of 0.5 g/d, still enables the surviving of the gigantic microbiota population. However, the composition of this residual flux namely the bile acid type, the conjugation rate and type (with taurine or glycine), and the hydroxylation extent have the foremost effect on the microbiota population and hence on the entire physiology. All the bile flux absorbed from the gut flows by the portal vein into the liver. This provides an elegant system of negative-feedback regulation of the bile acid synthesis, where bile acid reabsorption in the ileum signals through the gut-liver axis to inhibit the de novo synthesis in the liver of cholic acid from cholesterol. When the bile enterohepatic cycle becomes dysregulated, this leads to significant alterations, not only in the size and the makeup of the bile acid pool but also in the range of tissues and organs exposed to bile molecules. During the inter-digestive phase, most bile acids are stored and concentrated in the gallbladder but ~10% of the bile coming from the liver can flow into the duodenum during this period. In the postprandial state, the entry of macronutrients (i.e., fats, proteins, and carbohydrates) in the duodenum triggers gallbladder contractions and opening of the Oddi sphincter, resulting in the flow of bile to the duodenum. About 30% of the bile acids (mostly unconjugated bile acids) are absorbed in the upper small intestine by passive diffusion (Hegyi et  al. 2018, Guiastrennec et al. 2018).

References

295

References Adam A, Lopez HW, Leuillet M, Demigné C, Rémésy C (2003) Whole-wheat flour exerts cholesterol-­lowering in rats in its native form and after use in bread-making. Food Chem 80:337–344. https://doi.org/10.1016/S0308-8146(02)00269-8 Alamo AGD, Verstegen MWA, Hartog LAD, Ayala PPD, Villamide MJ (2009) Wheat starch digestion rate affects broiler performance. Poult Sci 88:1666–1675. https://doi.org/10.3382/ ps.2008-00502 Alberts DS, Ritenbaugh C, Story JA, Aickin M, Rees-McGee S, Buller MK, Atwood J, Phelps J, Ramanujam PS, Bellapravalu S, Patel J, Bettinger L, Clark L (1996) Randomized, double-­ blinded, placebo-controlled study of effect of wheat bran fiber and calcium on fecal bile acids in patients with resected adenomatous colon polyps. J Natl Cancer Inst 88:81–92 Bajor A, Gillberg PG, Abrahamsson H (2010) Bile acids: short and long term effects in the intestine. Scand J Gastroenterol 45:645–664. https://doi.org/10.3109/00365521003702734 Berend K, Hulsteijn LHV, Gans ROB (2012) Chloride: the queen of electrolytes? Eur J Intern Med 23:203–211. https://doi.org/10.1016/j.ejim.2011.11.013 Bhuket TP, Stollman NH (2016) Diverticular disease of the colon. In: Feldman M, Friedman LS, Brandt LJ (eds) Chap 121, Sleisenger and Fordtran’s gastrointestinal and liver disease, 10th edn. Elsevier https://www.clinicalkey.com/#!/browse/book/3-s2.0-C20121000197 Bianchi MA, Scazzina F, Rio DD, Valtueña S, Pellegrini N, Franzini L, Luisa Callegari M, Pellacani C, Buschini A, Zavaroni I, Brighenti F (2010) Ability of a high-total anti-oxidant capacity diet to increase stool weight and bowel antioxidant status in human subjects. Br J Nutr 104:1500–1507. https://doi.org/10.1017/S0007114510002424 Boland M (2016) Human digestion - a processing perspective. J Sci Food Agric 96:2275–2283. https://doi.org/10.1002/jsfa.7601 Bornhorst GM, Singh RP (2012) Bolus formation and disintegration during digestion of food carbohydrates. Compr Rev Food Sci Food Saf 11:101–118. https://doi. org/10.1111/j.1541-4337.2011.00172.x Bornhorst GM, Singh RP (2014) Gastric digestion in vivo and in vitro: how the structural aspects of food influence the digestion process. Annu Rev Food Sci Technol 5:111–132. https://doi. org/10.1146/annurev-food-030713-092346 Capuano E (2017) The behavior of dietary fiber in the gastrointestinal tract determines its physiological effect. Crit Rev Food Sci Nutr 57:3543–3564. https://doi.org/10.1080/10408398.201 6.1180501 Cecco CND, Ciolina M, Annibale B, Rengo M, Bellini D, Muscogiuri G, Maruotti A, Saba L, Iafrat F, Laghi A (2016) Prevalence and distribution of colonic diverticula assessed with CT colonography. Eur Radiol 26:639–645. https://doi.org/10.1007/s00330-015-3866Colon F, Trial P, Alberts DS, Einspahr JG, Earnest DL, Krutzsch MF, Lin P, Hess LM, Heddens DK, Roe DJ, Martı ME (2003) Fecal bile acid concentrations in a subpopulation of the wheat bran. Prevention 12:197–200 Cremer J, Arnoldini M, Hwa T (2017) Effect of water flow and chemical environment on microbiota growth and composition in the human colon. Proc Natl Acad Sci 114:6438–6443. https:// doi.org/10.1073/pnas.1619598114 Cronin CG, Delappe E, Lohan DG, Roche C, Murphy JM (2010) Normal small bowel wall characteristics on MR enterography. Eur J Radiol 75:207–211. https://doi.org/10.1016/j. ejrad.2009.04.066 Crowe FL, Appleby PN, Allen NE, Key TJ (2011) Diet and risk of diverticular disease in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC): prospective study of British vegetarians and non-vegetarians. BMJ 343:d4131. https://doi.org/10.1136/bmj. d4131 Cummings JH, Antoine J-M, Azpiroz F, Bourdet-Sicard R, Brandtzaeg P, Calder PC, Gibson GR, Guarner F, Isolauri E, Pannemans D, Shortt C, Tuijtelaars S, Watzl B (2004) PASSCLAIM1? Gut health and immunity. Eur J Nutr 43:ii118–ii173. https://doi.org/10.1007/s00394-004-1205-4

296

14 Digestion

Cuomo R, Cargiolli M, Cassarano S, Carabotti M, Annibale B (2018) Treatment of diverticular disease, targeting symptoms or underlying mechanism. Curr Opin Pharmacol 43:124–131. www.sciencedirect.com Dawson PA, Oelkers P (1995) Bile acid transporters. Curr Opin Lipidol 6:109–114. https://doi. org/10.1097/00041433-199504000-00009 Dawson PA, Lan T, Rao A (2009) Bile acid transporters. J Lipid Res 50:2340–2357. https://doi. org/10.1194/jlr.R900012-JLR200 Dietschy JM (1968) Mechanisms for the intestinal absorption of bile acids. J Lipid Res 9:297–309 Domínguez-Avila JA, Wall-Medrano A, Velderrain-Rodríguez GR, Chen CYO, Salazar-López NJ, Robles-Sánchez M, González-Aguilar GA (2017) Gastrointestinal interactions, absorption, splanchnic metabolism and pharmacokinetics of orally ingested phenolic compounds. Food Funct 8:15–38. https://doi.org/10.1039/c6fo01475e Eckburg PB, Bik EM, Bernstein CN, Purdom E, Dethlefsen L, Sargent M, Gill SR, Nelson KE, Relman DA (2005) Diversity of the human intestinal microbial flora. Science 308:1635–1638. www.sciencemag.org Egert M, Graaf AAD, Smidt H, Vos WMD, Venema K (2006) Beyond diversity: functional microbiomics of the human colon. Trend Microbiol 14:86–91. https://doi.org/10.1016/j. tim.2005.12.007 Engmann J, Burbidge AS (2013) Fluid mechanics of eating, swallowing and digestion-overview and perspectives. Food Funct 4:443–447. https://doi.org/10.1039/c2fo30184a Erik K, Knudsen B (2018) Microbial degradation of whole-grain complex carbohydrates and impact on short-chain fatty acids and health. Adv Nutr 6:206–213. https://doi.org/10.3945/ an.114.007450.206 Ferrebee CB, Dawson PA (2015) Metabolic effects of intestinal absorption and enterohepatic cycling of bile acids. Acta Pharm Sin B 5:129–134. https://doi.org/10.1016/j.apsb.2015.01.001 Forte JG (2010) The gastric parietal cell: at home and abroad. Eur Surg  - Acta Chir Austriaca 42:134–148. https://doi.org/10.1007/s10353-010-0539-9 Grundy MML, Edwards CH, Mackie AR, Gidley MJ, Butterworth PJ, Ellis PR (2016) Re-evaluation of the mechanisms of dietary fibre and implications for macronutrient bioaccessibility, digestion and postprandial metabolism. Br J Nutr 116:816–833. https://doi. org/10.1017/s0007114516002610 Guarner F, Malagelada JR (2003) Gut flora in health and disease. Lancet 361:512–519 Guiastrennec B, Sonne DP, Bergstrand M, Vilsbøll T, Knop FK, Karlsson MO (2018) Model-based prediction of plasma concentration and enterohepatic circulation of total bile acids in humans. CPT Pharmacometrics Syst Pharmacol 7:603–612. https://doi.org/10.1002/psp4.12325 Hamilton JP, Xie G, Raufman JP, Hogan S, Griffin TL, Packard CA, Chatfield DA, Hagey LR, Steinbach JH, Hofmann AF (2007) Human cecal bile acids: concentration and spectrum. Am J Physiol Liver Physiol 293:G256–G263. https://doi.org/10.1152/ajpgi.00027.2007 Hegyi P, Maléth J, Walters JR, Hofmann AF, Keely SJ (2018) Guts and gall: bile acids in regulation of intestinal epithelial function in health and disease. Physiol Rev 98:1983–2023. https://doi. org/10.1152/physrev.00054.2017 HMDB: http://www.hmdb.ca/hml Hofmann AF, Hagey LR (2014) Key discoveries in bile acid chemistry and biology and their clinical applications: history of the last eight decades. J Lipid Res 55:1553–1595. http://www.jlr.org Hooper LV, Midtvedt T, Gordon JI (2002) How host-microbial interactions shape the nutrient environment of the mammalian intestine. Annu Rev Nutr 22:283–307. https://doi.org/10.1146/ annurev.nutr.22.011602.092259 Hvolris MH, Piper TB, Hammer A, Jorgensen LN, Olsen L, Rahr HB, Nielsen KT, Laurberg S, Christensen IJ, Brunner N, Johansen JS, Davis JD, Dowell DL, Nielsen HJ (2016) Increased serological cancer-associated biomarker levels at large bowel endoscopy and risk of subsequent primary cancer. Scand J Gastroenterol 51:860–865. https://doi.org/10.3109/00365521. 2016.1144783

References

297

Ishizuka S, Tanaka S, Xu H, Hara H (2004) Fermentable dietary fiber potentiates the localization of immune cells in the rat large intestinal crypts. Exp Biol Med 229:876–884. https://doi. org/10.1177/153537020422900903 Jandhyala SM, Talukdar R, Subramanyam C, Vuyyuru H, Sasikala M, Reddy DN (2015) Role of the normal gut microbiota. World J Gastroenterol 21:8836–8847. https://doi.org/10.3748/wjg. v21.i29.8787 Joyce SA, Gahan CGM (2016) Bile acid modifications at the microbe-host interface: potential for nutraceutical and pharmaceutical interventions in host health. Annu Rev Food Sci Technol 7:313–333. https://doi.org/10.1146/annurev-food-041715-033159 Kopic S, Murek M, Geibel JP (2009) Revisiting the parietal cell. Am J Physiol Cell Physiol 298:C1–C10. https://doi.org/10.1152/ajpcell.00478.2009 Kuipers F, Bloks VW, Groen AK (2014) Beyond intestinal soap - bile acids in metabolic control. Nat Rev Endocrinol 10:488–498. https://doi.org/10.1038/nrendo.2014.60 Lampe JW, Slavin JL, Baglien KS, Thompson WO, Duane WC, Zavoral JH (1991) Serum lipid and fecal bile acid changes with cereal, vegetable, and sugar-beet fiber feeding. Am J Clin Nutr 53:1235–1241. https://doi.org/10.1093/ajcn/53.5.1235 Lan K, Su M, Xie G, Ferslew BC, Brouwer KLR, Rajani C, Liu C, Jia W (2016) Key role for the 12-hydroxy group in the negative ion fragmentation of unconjugated C24 bile acids. Anal Chem 88:7041–7048. https://doi.org/10.1021/acs.analchem.6b00573 Malik NA (2016) Solubilization and interaction studies of bile salts with surfactants and drugs: a review. Appl Biochem Biotechnol 179:179–201. https://doi.org/10.1007/s12010-016-1987-x Moghimipour E, Ameri A, Handali S (2015) Absorption-enhancing effects of bile salts. Molecules 20:14451–14473. https://doi.org/10.3390/molecules200814451 Molinaro A, Wahlström A, Marschall HU (2018) Role of bile acids in metabolic control. Trends Endocrinol Metab 29:31–41. https://doi.org/10.1016/j.tem.2017.11.002 MSD manual. https://www.msdmanuals.com/professional Muhammad A, Lamendola O, Daas A, Kumar A, Vidyarthi G (2014) Association between colonic diverticulosis and prevalence of colorectal polyps. Int J Color Dis 29:947–951. https://doi. org/10.1007/s00384-014-1908-9 Muinck EJD, Lundin KEA, Trosvik P (2017) Linking spatial structure and community-level biotic interactions through cooccurrence and time series modeling of the human intestinal microbiota. mSystem 2:e00086–e00017. https://doi.org/10.1128/mSystems.00086-17 Nandhra GK, Mark EB, Tanna GLD, Haase AM, Poulsen J, Christodoulides S, Kung V, Klinge MW, Knudsen K, Borghammer P, Andersen KO, Fynne L, Sutter N, Schlageter V, Krogh K, Drewes AM, Birch M, Scott M (2019) Normative values for region-specific colonic and gastrointestinal transit times in 111 healthy volunteers using the 3D-transit electromagnet tracking system: influence of age, gender, and body mass index. Neurogastroenterol Motil 2019:e13734. https://doi.org/10.1111/nmo.13734 Northfield TC, McColl I (1973) Postprandial concentrations of free and conjugated bile acids down the length of the normal human small intestine. Gut 14:513–518. https://doi.org/10.1136/ gut.14.7.513 Orchel A, Dzierzewicz Z, Parfiniewicz B, Weģlarz L, Wilczok T (2005) Butyrate-induced differentiation of colon cancer cells is PKC and JNK dependent. Dig Dis Sci 50:490–498. https://doi. org/10.1007/s10620-005-2463-6 Peery AF, Keku TO, Martin CF, Eluri S, Runge T, Galanko JA, Sandler RS (2016) Distribution and characteristics of colonic diverticula in a United States screening population. Clin Gastroenterol Hepatol 14:980–985. https://doi.org/10.1016/j.cgh.2016.01.020 Pritchard SE, Marciani L, Garsed KC, Hoad CL, Thongborisute W, Roberts E, Gowland PA, Spiller RC (2014) Fasting and postprandial volumes of the undisturbed colon: normal ­values and changes in diarrhea-predominant irritable bowel syndrome measured using serial MRI. Neurogastroenterol Motil 26:124–130. https://doi.org/10.1111/nmo.12243 Ridlon JM, Kang DJ, Hylemon PB, Bajaj JS (2014) Bile acids and the gut microbiome. Curr Opin Gastroenterol 30:332–338. https://doi.org/10.1097/MOG.0000000000000057

298

14 Digestion

Romański K (2008) The role and mechanism of action of bile acidsin the digestive system – bile acids in the gut. Adv Clin Exp Med 17:83–89 Rosicka-Kaczmarek J, Kwaśniewska-Karolak I, Nebesny E, Miśkiewicz K (2013) Influence of variety and year of wheat cultivation on the chemical composition of starch and properties of glucose hydrolysates. J Cereal Sci 57:98–106. https://doi.org/10.1016/j.jcs.2012.10.003 Ruiz L, Margolles A, Sánchez B (2013) Bile resistance mechanisms in Lactobacillus and Bifidobacterium. Front Microbiol 4:396. https://doi.org/10.3389/fmicb.2013.00396 Sadahiro S, Ohmura T, Yamada Y, Saito T, Taki Y (1992) Analysis of length and surface area of each segment of the large intestine according to age, sex and physique. Surg Radiol Anat 14:251–257. https://doi.org/10.1007/BF01794949 Sadeghpour A, Rappolt M, Misra S, Kulkarni CV (2018) Bile salts caught in the act: from emulsification to nanostructural reorganization of lipid self-assemblies. Langmuir 34:13626–13637. https://doi.org/10.1021/acs.langmuir.8b02343 Schlörmann W, Hiller B, Jahns F, Zöger R, Hennemeier I, Wilhelm A, Lindhauer MG, Glei M (2012) Chemopreventive effects of in vitro digested and fermented bread in human colon cells. Eur J Nutr 51:827–839. https://doi.org/10.1007/s00394-011-0262-8 Shani-Levi C, Alvito P, Andrés A, Assunção R, Barberá R, Blanquet-Diot S, Bourlieu C, Brodkorb A, Cilla A, Deglaire A, Denis S, Dupont D, Heredia A, Karakaya S, Giosafatto CVL, Mariniello L, Martins C, Ménard O, El SN, Vegarud GE, Ulleberg E, Lesmes U (2017) Extending in vitro digestion models to specific human populations: perspectives, practical tools and bio-relevant information. Trends Food Sci Technol 60:52–63. https://doi.org/10.1016/j.tifs.2016.10.017 Sipka S, Bruckner G (2014) The immunomodulatory role of bile acids. Int Arch Allergy Immunol 165:1–8. https://doi.org/10.1159/000366100 Staley C, Weingarden AR, Khoruts A, Sadowsky MJ (2017) Interaction of gut microbiota with bile acid metabolism and its influence on disease states. Appl Microbiol Biotechnol 101:47–64. https://doi.org/10.1007/s00253-016-8006-6 Štěrbová L, Bradová J, Sedláček T, Holasová M, Fiedlerová V, Dvořáček V, Smrčková P (2016) Influence of technological processing of wheat grain on starch digestibility and resistant starch content. Starch 68:593–602. https://doi.org/10.1002/star.201500162 Sundin OH, Mendoza-Ladd A, Zeng M, Diaz-Arévalo D, Morales E, Fagan BM, Ordoñez J, Velez P, Antony N, McCallum RW (2017) The human jejunum has an endogenous microbiota that differs from those in the oral cavity and colon. BMC Microbiol 17:160. https://doi.org/10.1186/ s12866-017-1059-6 Svihus B, Hervik AK (2016) Digestion and metabolic fates of starch, and its relation to major nutrition-related health problems: a review. Starch 68:302–313. https://doi.org/10.1002/ star.201500295 Tantamango YM, Knutsen SF, Beeson WL, Fraser G (2011) Foods and food groups associated with the incidence of colorectal polyps: the adventist health study. Nutr Cancer 63:565–572. https://doi.org/10.1080/01635581.2011.551988 Vallim TQDA, Tarling EJ, Edwards PA (2013) Pleiotropic roles of bile acids in metabolism. Cell Metab 17:657–669. https://doi.org/10.1016/j.cmet.2013.03.013 Verspreet J, Damen B, Broekaert WF, Verbeke K, Delcour JA, Courtin CM (2016) A critical look at prebiotics within the dietary fiber concept. Annu Rev Food Sci Technol 7:167–190. https:// doi.org/10.1146/annurev-food-081315-032749 Vertzoni M, Augustijns P, Grimm M, Koziolek M, Lemmens G, Parrott N, Pentafragka C, Reppas C, Rubbens J, Αbeele JVD, Vanuytsel T, Weitschies W, Wilson CG (2019) Impact of regional differences along the gastrointestinal tract of healthy adults on oral drug absorption: an UNGAP review. Eur J Pharmaceutl Sci 134:153–175. https://doi.org/10.1016/j.ejps.2019.04.013 Vijayvargiya P, Busciglio I, Burton D, Donato L, Lueke A, Camilleri M (2018) Bile acid deficiency in a subgroup of patients with irritable bowel syndrome with constipation based on biomarkers in serum and fecal samples. Clin Gastroenterol Hepatol 16:522–527. https://doi.org/10.1016/j. cgh.2017.06.039

References

299

Wald A (2019) Bile acids and bowel function: do they play a role in constipation-associated irritable bowel syndrome? Clin Gastroenterol Hepatol 16:486–487. https://doi.org/10.1016/j. cgh.2017.11.021 Walker MM, Talley NJ (2014) Review article: Bacteria and pathogenesis of disease in the upper gastrointestinal tract - beyond the era of helicobacter pylori. Aliment Pharmacol Ther 39:767– 779. https://doi.org/10.1111/apt.12666 Walter J, Ley R (2010) The human gut microbiome: ecology and recent evolutionary changes. Annu Rev Microbiol 65:411–429. https://doi.org/10.1146/annurev-micro-090110-102830 Widodo AE, Nolan JV, Iji PA (2015) The nutritional value of new varieties of high-yielding triticale: nutrient composition and in vitro digestibility. South African J Anim Sci 45:60–73. https://doi.org/10.4314/sajas.v45i1.8 Williams AR, Balasooriya BAW, Day DW (1982) Polyps and cancer of the large bowel: a necropsy study in Liverpool. Gut 23:835–842 Zhou Z, Topping DL, Morell MK, Bird AR (2010) Changes in starch physical characteristics following digestion of foods in the human small intestine. Br J Nutr 104:573–581. https://doi. org/10.1017/S0007114510000875 Zhou ZK, Hua ZT, Yang Y, Zheng PY, Zhang Y, Chen XS (2014) Molecular characteristics of new wheat starch and its digestion behaviours. J Integr Agric 13:1146–1153. https://doi. org/10.1016/S2095-3119(13)60621-8

Chapter 15

The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled Epidemiological Studies

 he Decrease in the Non-communicable Diseases by T the Consumption of the Whole-Wheat Bread The whole-wheat consumption elicits many impacts on health and eventually on the disability on aging and mortality. We have collected the available published data for the effect of the intake of the whole-wheat bread on the incidence of most of the main NCD (non-communicable diseases). We presume that the intake of the whole-­ wheat has a similar remarkable impact on the infectious diseases as for those found for the NCD. However, we could not locate such data for infectious diseases such as influenza or tuberculosis. Even though the whole-wheat intake well established today by the nutritionists as a robust pillar of sensible nutrition, the market does not respond accordingly. The common consumer does not respond accordingly to this pillar notion. The vast majority of the public in Western societies consume wheat products baked from the refined flour. The typical consumer, consume the bread wheat after the flour had excluded most of the nutritious ingredients. Assuming we will take off from the fruits and the vegetable all the dietary fiber, the vitamins, and the anti-oxidants. Presently, such withdrawal of the most nutritious ingredients has not practiced for the fruits and the vegetable but it has well practices for wheat for a long period. Such disadvantage does not restrict to the Western societies because within the rice consumers such a practice is most prevails as the whole-rice consumed only on a limited scale. The long-run and the wide-scaled epidemiological studies with the reliable information of the morbidity/mortality is the golden ruler for the evaluation of the advantage of the whole-wheat intake on human health. Because of the data collection accumulated within a very long run, some additional methodologies for the evaluation of the outcomes of the whole-wheat intake are most helpful. While presently, the vast majority of the support for the superiority of the whole-wheat upon refined-­ ­ flour wheat accumulated from the wide-scaled epidemiological studies there is a crucial need for the introduction of additional methodologies. © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_15

301

302

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

The Critical Role of the Large Numbers Nutritional recommendations must support robust outcomes of nutritional experimentation. However, in the common practice, we often subjected to the advertisements suggesting the most promising healthy food that the recommendation based on nutritional experimentation conducted along with a limited number of weeks with some tens of subjects. Even such a study might be most reliable and published in a reputed journal it cannot comprise a base for any nutritional recommendation. Because of the high variability between the subjects physiology, the eating habits, and the variability in the composition of the same food item any recommendation or suggestion require a very wide scaled and a large number of participants and also the accumulation of a large number of studies that conducted by different research groups. To show the effect of the large number we exemplify a published study aimed to show the optimal range of serum calcidiol (vitamin D). The Non-Communicable Disease (NCD or non-communicable/non-­ infectious/non-transmissible) is a medical condition or disease that does not cause by the infectious agents. The NCDs can refer to the chronic diseases that last for long periods and progressed slowly. Sometimes, the NCDs result in rapid deaths such as seen in certain autoimmune diseases, heart diseases, stroke, cancer diseases, chronic kidney disease, osteoporosis, Alzheimer’s disease, cataracts, and others. NCDs are the leading global cause of death. In 2012, the NCD caused 68% of all deaths up from 60% in 2000 while about half the cases were under 70 y (Wikipedia). The outcomes of the effects of the whole-wheat have presented with the data availability that presumably well represents the majority of the NCD episodes within the investigated population. Except for the NCD critical effect on mortality, the NCD also markedly affects the aging phenomenon and in particular affects the disability on aging that becomes the main burden for the social health facilities in industrialized societies. The communicable/transmitted/or infectious diseases are most limited in their incidence or they are not well diagnosed and commonly do not report in the EHR (electronic health records). When we collected the data of 106  K subjects along 48  months (by EHR-­ electronic health records system), no significant effect shown between the upper limit of 36 ng/mL and the higher levels that evaluated according to the mortality/ morbidity data (unpublished results). Such a statistical significance is most crucial to establishing the main argument of the study. Only when we collected the data from 423  k subjects along 54  months the required statistical value gained (Dror et al. 2013). The advantage of the whole-wheat intake (Table  15.1) have collected from ~37 M subjects to assure reliable conclusions.

Publication Site Morbidity categories 1 Incidence of colorectal malignancy Willett et al. (1990) US Jacobs et al. (1998a) US, EU Negri et al. (2002) Italy Fuchs et al. (1999) US Terry et al. (2001) Sweden Larsson et al. (2005) Sweden Schatzkin et al. (2007) US Egeberg et al. (2010) Denmark Aune et al. (2011) 8 studies Murphy et al. (2012) Europe Hansen et al. (2012) Scandinavia Kyrø et al. (2013) Scandinavia Ben et al. (2014) 9 studies Knudsen et al. (2014) Scandinavia Zhong et al. (2014) Guangdong, China Kunzmann et al. (2015) US Vulcan et al. (2015) Malmo Gianfredia et al. (2018) 25 studies Ma et al. (2018) 12 studies Total subjects for colorectal malignancy, M 2 Incidence of upper gut malignancy Jacobs et al. (1998b) EU, US 5.5

122 11 8 89 61 61 490 56 954 521 108 108 132 120 1.2 58 28 2620

1975–1992 8

1976–1980 1970–1994 1983–1996 1976–1986 1987–2000 1987–2004 1995–2000 1993–1997 1980–2008 1992–2000 1997–2008 1991–2002 1993–2012 1992–1998 2010–2012 1996–2009 1991–2010 1990–2015 1994–2015

Period

Unit

29–85

WG

g

cere g/d WG g/d cere g/d cere g/d cere g/d WG Qu serv WG g/d WG per 50 g cere g/d cere g/d cere g/d WG g/d cere g/d 30–64 WGb Qu 30–75 CF Qu 67 CF g/d 60 serv Qu DF g/d 34–79 DF g/d Average for colorectal malignancy

30–55 F 35–75 40–75 34–59 F 53 40–76 50–71 50–64 34–75 >35 53 40–65

Subject K Age/gender Fiber type

0.74 0.90 0.60 0.92 0.91 0.76 0.79 0.94 0.87 0.83 0.71 0.86 0.76 0.69 0.48 0.78 0.72 0.74 0.83 0.78

(continued)

High 0.71

High 30 17 70 High High 3.75 5.4 High High High

Low 14 10 30 Low Low 1.8 2.4 Low Low Low

Low

7.3 High High 4.8 13.6 5 2.0

2.6 Low Low 1 5.7 1 0.4

Rangea Relative Low High risk

Table 15.1  The effect of the whole-wheat intake on the decrease in the relative risk (RR) of morbidity and mortality as evaluated in 20 categories

The Critical Role of the Large Numbers 303

Publication Site Chen et al. (2002) Nebraska Schatzkin et al. (2008) US Xu et al. (2019) 7 studies Total subjects for upper gut malignancy, M 3 Incidence of pancreatic malignancy Jacobs et al. (1998b) EU, US Chan et al. (2007) CA Lei et al. (2016) US, Europe Total subjects for pancreatic malignancy, M 4 Incidence of breast malignancy Farvid et al. (2016b) US Mourouti et al. (2016) Athens, Greece Farvid et al. (2016a) New England Chen et al. (2016a, b) 24 studies Xiao et al. (2018) 11 studies Total subjects for breast malignancy, M 5 Incidence of ovarian malignancy Zheng et al. (2018) 13 studies Total subjects for ovarian malignancy, M 6 Incidence of hepatocellular carcinoma Yang et al. (2019) US Total subjects for hepatocellular carcinoma, M 7 Incidence of all-cause malignancy Jacobs et al. (1998a) 40 studies Jacobs et al. (2001) Norway

Table 15.1 (continued)

25–42 CF 56 WG 27–44 WG 18–103 WG 26–75 WG Average for breast malignancy

1991–2011 2010–2012 1998–2013 1980–2011 1987–2016

46

WG WG

g/d Qu

63 WG Ter Average for hepatocellular carcinoma

1984–2010 125 0.13

1977–1994 66

2–87 DF Average for ovarian malignancy

1987–2016 142 0.14

g/d times/d serv

35–79 WG g 45–85 WG serv 21–85 WG Average for pancreatic malignancy

1976–1987 3 1995–1999 2.2 1983–2009 44 0.05 91 0.5 91 3600 131 3.9

Age/gender Fiber type 62 WG 50–71 cere WG Average for upper gut malignancy

0.1

8

Low

2.9 2.2 1 Low Low

Low Low Low

0.90 0.49 0.91 0.88 0.84

3.5

36

0.85 0.79

0.63

High 0.78

8.9 3.8 5 High High

0.63

0.78

0.80

0.70

Relative risk 0.50 0.49 0.61 0.58 High 0.74 High 0.60 High 0.76

Rangea Low High Unit Qu serv 1st 4th Qu 10 28 Low High

Subject K Period 1992–1994 1 1995–2003 492 1999–2009 40 0.5

304 15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

Publication Site Knudsen et al. (2014) Iowa Aune et al. (2013) 5 studies Total subjects for all-cause malignancy, M Cardiovascular categories 8 Incidence of cardiovascular morbidity Fraser (2011) Calif Liu et al. (1999) US Steffen et al. (2003) US Mozaffarian et al. (2014) US Jensen et al. (2004) US Flight and Clifton (2006) US 10 studies Mellen et al. (2008) US, Norway, 7 studies Ye et al. (2012) 10 studies Helnæs et al. (2016) Copenhagen/Aarhus Helnæs et al. (2016) Copenhagen/Aarhus Bechtholda et al. (2016) 7 studies AlEssa et al. (2018) US Total subjects for CVD, M 9 Incidence of stroke Liu et al. (2003) MS-US Steffen et al. (2003) US Larsson and Wolk (2014) Sweden Fang et al. (2015) US, Finland 6 studies Aune et al. (2016) 6 studies Zhang et al. (2015) 14 studies Bechtholda et al. (2016) 7 studies 1975–1984 1987–2000 1997–2008 1999–2009 1998–2010 1991–2014 1987–2016

1977–1982 1984–1990 1987–1989 1989–2000 1986–2000 1981–2003 1980–2005 1998–2008 1990–2009 1990–2009 1987–2016 1984–2012

76 12 70 247 247 161 7

50–64 M 58–64 F

28 30 7 1830 2.9 38–63 F 45–64 45–83 38–84

52

>25 38–63 45–64 >65 40–75 M Adults 40–98

59 75 12 3.6 43 546 285

WG cere CB WG WG WG WG

WG cere cere CF WG CF WG WG WG WG WG cereF Average for CVD 1st Low Low Low 30 2.8

0.1 0.1 1.2 3.5

2.7 3.0 High High High High 180

(continued)

0.69 0.75 0.94 0.86 0.86 0.77 0.91

0.78

Relative risk 0.82 0.89 0.84

0.56 0.79 0.72 0.79 0.82 0.90 5th 0.79 High 0.79 High 0.75 High 0.73 180 0.85 9.0 0.82 2.7 3.0 7.5 42

Rangea Low High 0.7 20 Low High

Qu serv 0.13 serv 0.1 Qu Low Low Low Low g/d 30

Qu g/d Qu g/d g/d g/d

Ser Ser g/d g/d 10 g/d Qu

Subject K Period Age/gender Fiber type Unit 1986–1999 33 55–69 CF Ter 674 WG 0.77 Average for all-cause malignancy The Critical Role of the Large Numbers 305

Publication Site Juan et al. (2017) US Sun et al. (2019) Shenzhenc Total subjects for stroke, M 10 Incidence of hypertension Esmaillzadeh et al. (2005) Tehran Wang et al. (2007) US Flint et al. (2009) US Total subjects for hypertension, M Metabolic categories 11 Incidence of diabetes type 2 Meyer et al. (2000) Iowa Liu et al. (2000) US Fung et al. (2002) US-MA Esmaillzadeh et al. (2005) Teheran Munter et al. (2007) 6 studies Ye et al. (2012) 6 studies Aune et al. (2013) 10 studies Parker et al. (2013) US Cho et al. (2013) 11 studies Yao et al. (2014) 12 studies Chanson-Rolle et al. (2015) 8 studies Kuijsten et al. (2015) 12 studies Kyrø et al. (2018) Denmark Total subjects for diabetes type 2, M

Table 15.1 (continued)

72 620 359 316 401 55 2.3

55–69 F 42 F 40–75 M 18–74 21–75

1986–1992 36 1984–1990 75 1986–1994 43 0.8 2000–2007 286 2000–2007 1994–1998 1997–2004 1974–2013 1991–2013 1997–2015 1993–2010

18–74 WG bread 53 F WG 53 WG Average for hypertension

0.8 1992–2005 29 1986–2004 32 0.06

CF WG WG WG bread WG WG WG 63 F WG 21–75 cere 45–70 CF 18–79 WG 20–79 CF 50–65 WG Average for diabetes type 2

Age/gender Fiber type 30–75 WG 62 DHPPAd Average for stroke

Subject K Period 1976–2016 173 2011–2016 1980 3.0

Qu 10 g/d 38 g/d

Qu serv

g/d Q serv Q serv Qu 32 g

Qu Ser g

Unit Qu g/d Quin

9.4 2.7 3.2 229 High High 2.5 High High 69 High High

Low Low 0 Low Low 11 Low Low

229 5 46

2.7 0.1 0.4 6

6 1 3

Rangea Low High 5 26 1 5

0.64 0.75 0.70 0.88 0.79 0.74 0.68 0.75 0.72 0.81 0.69 0.75 0.76

0.84 0.77 0.81

0.74

0.81

Relative risk 0.84 0.63 0.81

306 15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

Publication Site Period 12 Incidence of metabolic syndrome Sahyoun et al. (2006) US-MA 1981–1984 Total subjects for metabolic syndrome, M 13 Incidence of hip fracture Jacobs et al. (2010) Iowa 1986–2004 Total subjects for hip fracture, M Causes of mortality categories 14 Incidence of mortality attributed to all cause malignancy Jacobs et al. (1999) Minnesota 1995–1992 Jacobs et al. (2001) Norway 1977–1994 Huang et al. (2015) US 1995–2009 Zong et al. (2016) US, Scandinavia, 14 studies 1973–2013 Johnsen et al. (2015) Scandinavia 1992–2009 Benisi-Kohansal et al. (2016) 14 studies Chen et al. (2016a, b) 8 studies 1996–2015 Hajishafiee et al. (2016) 12 studies 1996–2015 Zhang et al. (2018) 14 studies 1999–2016 Total subjects for all cause malignancy, M 15 Incidence of mortality attributed to cardiovascular diseases Jacobs et al. (1998b) US-MN 1988–1995 Jacobs et al. (1999) US-MN 1995–1992 Jacobs et al. (2001) Norway 1977–1994 Sahyoun et al. (2006) US-MA 1981–1984 Flight and Clifton (2006) US 10 studies 1981–2003 Crowe et al. (2012) 10 EU countries 1992–2000 Rebello et al. (2014) Singapore 1993–2011 Li et al. (2014) US 1976–2006 40–83 45–74 30–75

55–69 F 62 F 46 >60

35 38 66 1 546 502 53 2.5

WG WG WG WG CF CF WG CF

WG g/d WG Q CF g/d WG serv WG Qu WG WG CF 30–84 WG Average for mortality of malignancy

765 835 3.7

62 F 46 50–71 16–98 30–64 16–79

38 66 367 786 120 715

Q serv g/d Qu Qu serv 10 g/d g/d Ter g/d

3 Low 15

0.3

0.89 0.79 0.75 0.88 0.78 0.94 0.89 0.85 0.94

0.81

0.46

0.86

0.81

0.46

(continued)

0.70 0.82 0.77 2.3 0.48 0.75 13 0.83 High 0.73 31 0.73

3.2 23

10.2 High 4 High High High High

2 Low 1 Low Low Low Low

0.2 1.5

23

3.7

2.3

1.5

0.26

F WG Average for hip fracture

15 0.015

serv

>60 WG Qu serv 0.3 Average for metabolic syndrome

Unit

Rangea Relative Low High risk

1 0.001

Subject K Age/gender Fiber type The Critical Role of the Large Numbers 307

Publication Site Period Wu et al. (2015) US 1984–2010 Huang et al. (2015) US 1995–2009 Johnsen et al. (2015) Scandinavia 1992–2009 Zong et al. (2016) US, Scandinavia, 14 studies 1973–2013 Benisi-Kohansal et al. (2016) 14 studies Chen et al. (2016a, b) 12 studies 1996–2015 Hajishafiee et al. (2016) 12 studies 1996–2015 Wei et al. (2016) 12 studies 2001–2015 Zhang et al. (2018) 8 studies 1999–2016 Total subjects for CDV, M 16 Incidence of mortality attributed to stroke Jacobs et al. (1999) US-MN 1995–1992 Johnsen et al. (2015) Scandinavia 1992–2009 Total subjects for stroke, M 17 Incidence of mortality attributed to diabetes type 2 Huang et al. (2015) US 1995–2009 Johnsen et al. (2015) Scandinavia 1992–2009 Aune et al. (2016) 5 studies 2007–2015 Total subjects for diabetes type 2, M 18 Incidence of mortality attributed to inflammatory diseases Jacobs et al. (1999) US-MN 1995–1992 Jacobs et al. (2001) Norway 1977–1994 Jacobs et al. (2007) Iowa 1986–2003 Huang et al. (2015) US 1995–2009 Hajishafiee et al. (2016) 3 studies 2010–2015

Table 15.1 (continued)

CF WG WG Average for diabetes type 2 62 F 46 61 F 50–71

38 66 27 367 562

WG WG WG CF CF

50–71 30–64

62 F WG 30–64 WG Average for mortality of stroke

Fiber type WG CF WG WG WG WG CF WG 30–84 WG Average for mortality of CDV

Age/gender 52 50–71 30–64 16–98 16–79

367 120 634 1.1

120 0.12

765 817 595 5.5

Subject K 70 367 120 786 715

g Qu serv g

g Qu

g Qu

Unit g/d g/d Qu serv

0.26 2 Low

1.5

2 1 Low

1.5 1

0.87 0.86

0.82 0.65 3.7 0.79 10.2 0.73 High 0.83

23

0.82

0.87

Relative risk 0.86 0.70 0.71 0.82 0.84 0.82 0.80 0.78 0.83 0.76

10.2 0.54 4 1.28 High 0.64

23 4

Rangea Low High 5 44 2 10.2 1 4 Low High Low High Low High Low High Low High Low High

308 15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

413 95 723 662 4.80 37 30–84

16–79

WG WG WG cer CF WG WG WG WG CF WG WG WG

30–64 62 F 46 45–64 50–71 16–98

120 38 66 12 367 786 806 715

Qu g Q serv g serv g

Qu

3.0 10.2 High High High High High High High High

0.1 2 Low Low Low Low Low Low Low Low

0.77

4 23

1 1.5

0.64 0.86 0.75 0.77 0.72 0.84 0.82 0.85 0.78 0.81 0.86 0.82 0.84

0.75

0.80

0.72

CF WG 30–64 WG Average for respiratory diseases

10.2 0.64 High 0.81 4 0.71

2 Low 1

50–71

367 639 120 1.1

g

Rangea Relative Low High risk 0.76

Subject K Age/gender Fiber type Unit 1.1 Average for inflammatory diseases

Cere cereal, WG whole-grain, Qu quartiles, serv servings, CF crude fiber, CereF Cereal fiber, RR relative risk, Ter tertile a The criterion for the evaluation was mostly the intake of the upper quartile/quintile range versus the lower one b The plasma concentrations of alkylresorcinol homologs measured for the evaluation of whole-wheat intake c Department of Neurology, People’s Hospital of Shenzhen, Guangdong, China d DHPPA – 3-(3,5-dihydroxyphenyl)-1-propanoic acid (DHPPA), a biomarker of whole-grain wheat and rye intake

Publication Site Period Total subjects for inflammatory diseases, M 19 Incidence of mortality attributed to respiratory diseases Huang et al. (2015) US 1995–2009 Aune et al. (2016) 4 studies 2007–2015 Hajishafiee et al. (2016) Scandinavia 1992–2009 Total subjects for respiratory diseases, M 20 Incidence of all-cause mortality Johnsen et al. (2015) Scandinavia 1992–2009 Jacobs et al. (1999) Minnesota 1995–1992 Jacobs et al. (2001) Norway 1977–1994 Steffen et al. (2003) US 1987–1989 Huang et al. (2015) US 1995–2009 Zong et al. (2016) US, Scandinavia 1973–2013 Aune et al. (2016) 9 studies 2003–2015 Benisi-Kohansal et al. (2016) 14 studies Chen et al. (2016a, b) 13 studies 2003–2015 Hajishafiee et al. (2016) 3 studies 2010–2015 Wei et al. (2016) 11 studies 2001–2015 Ma et al. (2016) 10 studies 2001–2015 Zhang et al. (2018) 9 studies 1999–2016 Total subjects for all-cause mortality, M Total subjects for all categories, M Average for 20 categories Average for all 128 main studies of the 20 categories

The Critical Role of the Large Numbers 309

310

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

We presume the data accuracy of the studies for the dietary effect on the morbidity/mortality is lower than that might collected from the EHR, but presently data for the whole-wheat bread intake and any biomarker that related to the whole-wheat are not available in accessible and wide-spread EHR.

 he Obstacles to the Investigation of the Effect T of the Whole-­Wheat Intake The methodology of animal experimentation is a well-known efficient tool to investigate and evaluate basic metabolic events and in particular the effect of the specific ingredients on the metabolic biomarkers. The issue of whole-wheat consumption has investigated only on a very limited scale by employing animal experimentation, because of the two main obstacles are: (a) Our colonic environment differs entirely from that of any laboratory animal. Our colon also differed from those of the other primates with the highest capacity of our colon and the unique highest concentration of the microbiota. The immune induction by the colon has a particular role in human with a different structure of the cellular envelope than all the other mammals. (b) The very long-run period needed for the evaluation of the beneficial effect of the whole-wheat on our physiology and in particular the effect of the whole-­ wheat intake on aging.

 he Effects of the Whole-Wheat Intake on the NCD T (Non-­communicable Diseases) in Wide Scaled Studies We have collected data that describe the decrease in the relative risk values for the NCD that generated by the whole-wheat intake and that has published in reputable journals. These relative risk values for the morbidity/mortality analyzed on more than 400 cited studies and 125 analyses that part of them are meta-analyses based on many other studies. These articles have published mainly in 15 journals generally defined as medical journals and 11 journals that generally defined as nutritional journals. Such a wide range of epidemiological studies published mostly in the reputed journals. The decrease in the relative risk produced by the intake of the whole-wheat collected from the majority of the available nutritional studies. The definitions of the morbidities and the causes of mortality copied from the data of the evaluated study. The categories for the calculation of the relative risks have copied from the published articles.

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We identified 20 categories with reputable and adequate data for the comparison of effects of the whole-wheat bread versus bread baked from refined flour as follows: 1. Colorectal malignancy; 2. Upper gut malignancy; 3. Pancreatic malignancy; 4. Breast malignancy; 5. Ovarian malignancy; 6. The incidence of hepatocellular carcinoma; 7. All-cause malignancy; 8. Cardiovascular morbidity; 9. Stroke; 10. Hypertension; 11. Diabetes type 2; 12. Metabolic syndrome; 13. Hip fracture; 14. Mortality attributed to malignancy; 15. Mortality attributed to cardiovascular diseases; 16. Mortality attributed to stroke; 17. Mortality attributed to diabetes type 2; 18. Mortality attributed to inflammatory diseases; 19. Mortality attributed to respiratory diseases; 20. All-cause mortality. This list includes 13 morbidity categories (7 malignancy, 3 cardiovascular, and 3 metabolic) and 7 mortality categories. Some of the collected studies are the results of the large meta-analyses and thus the total population that counted (Table 15.1) presumably exceeds the 37  M subjects. Because each of the meta-analyses (Table 15.1) contains several studies, some of the studied counted more than once but they evaluated separately by different surveyors and research groups. Because of the considerable heterogeneity of the studies, the combined effect of most of the studies into one group for performing a meta-analysis does not sound logical. The following terms of the heterogeneity factors have counted: (a) The prognostic parameters and the outcome consequences are different. (b) The prognostic parameters include whole-grain weight, cereal weight, cereal fiber weight, the weight of whole-wheat bread, quartiles or quintiles of any of the measures, high versus low intake of any measure and calculations made for 10 g/d for any of the measures. (c) The 20 outcome consequences are burdens without a uniform definition of the burden intensity (except for mortality). Infectious diseases, such as influenza, might also be evaluated for the effect of the whole-wheat intake. Unfortunately, we could not locate any large-scale study for the effect of infectious disease.

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We could not locate data for the effect of the whole-wheat intake in the two most important categories that normally developed in the long run: 1. The combined effect of any morbidity. Such an inquiry may show us the total effect of the whole-wheat on the general health status and might be most impressive. However, the collected data cannot support the calculation of the combined effect because additive manipulation of various relative-risk is not acceptable. 2. The effect of the intake of the whole-wheat bread on a typical biomarker of aging. Unfortunately, no accepted and consensual parameter attributed to the aging designation is presently available. Because whole-wheat has a marked effect on our health status, the impact of the whole-wheat believed to affect the aging progression. The total observation number describing the decrease in the relative risks for 20 categories of morbidity is around 37 M that published in hundreds of studies. Many of the publications presented here (Table 15.1) are meta-analyses containing up to tens of original studies thus, duplications in the counted observations were not identified and included. However, in some of the meta-analyses, the subject number was not specified and the subject number did not show. All these studies published in many reputable journals, by many hundreds of scholars, and accordingly the studies analyzed by many nutritional approached, presumably calculated by almost all the available statistical devices, and evaluated for publication by an uncounted number of referees. The total average relative risk for the morbidity incidence is 0.75. Even figure 0.75 for the average relative risk is most impressive, we presume that with the presently available data we cannot evaluate the differences in the magnitude of the relative risk between the 20 categories. Presumably, no other staple food has shown such an effect of 0.75 relative risks for the main NCD of Western society. With many other former recommendations to consume whole-wheat bread these data strongly support such a recommendation. Because the low intake of the whole wheat in other societies and in particular because the limited available data, we cannot generalize the strong recommendation for the whole bread intake for the other societies. As for the other whole-grain items, the available data is most restricted. Summary of all the relative risk data (Table  15.2) shows five main category groups namely malignancy, coronary vascular, and mortality attributed to seven categories of morbidity. The data for some of the 20 distinct categories colorectal malignancy, breast malignancy, cardiovascular morbidity, stroke, diabetes type 2, shows a very intensive research activity in the whole wheat intake and those diseases that counted altogether the major burden for the western societies. The subject number for the morbidity categories is the highest for the colorectal and breast malignancy followed by cardiovascular and stroke morbidities and diabetes type 2.

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Table 15.2  Summary of the 20 categories (presented in Table 15.1) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Colorectal malignancy Upper gut malignancy Pancreatic malignancy Breast malignancy Ovarian malignancy Hepatocellular carcinoma Malignancy, all-cause All malignancy categories Cardiovascular morbidity Stroke Hypertension All CVD categories (8–10) Diabetes type 2 Metabolic syndrome Hip fracture All metabolic categories (11–13) Mortality attributed to malignancy, all types Cardiovascular diseases Stroke Diabetes type 2 Inflammatory diseases Respiratory diseases All-cause mortality All mortality categories (14–20) Relative risk, the average of all main studies The total subject number, M

Relative risk 0.78 0.58 0.70 0.80 0.78 0.63 0.84 0.80 0.78 0.81 0.81 0.80 0.74 0.46 0.81 0.75 0.86 0.76 0.87 0.82 0.76 0.72 0.80 0.80 0.75

Subject number M 5.5 0.5 0.05 3.9 0.14 0.13 0.77 2.9 3 0.06 2.3 0.001 0.015 3.7 5.5 0.12 1.1 1.1 1.1 4.8

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According to the presented evidence, we forecast that the shift in the practice of the bread intake for a considerable part of the population should shortly affect the health statistics and the average age of the onset of disability on aging.

 etailed Description of the Effects of the Whole-Wheat Intake D on the Discrete Burdens  he Incidence of the Colorectal Malignancy (Table 15.1, T Category 1) In 19 epidemiological studies with 5.5 M subjects, an average relative risk of 0.78 (Table 15.1) with a range of 0.48–0.92 between studies is presented. Most of the studies, 15, comprise both genders while 2 large-scaled studies run only in females.

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The capacity of the whole-grain intake to scavenge the free radicals and the clear effect of such intake to reduce the incidence of colorectal cancer as it justifies the main approach presented in this book. With 19 large-scaled epidemiological studies with the average and the median (between the studies) of 0.75 for relative risk and many additional other studies the whole-grain effect is most persuading and justifies suggestion of whole-wheat intake for the general population. In the absence of contradicted evidence patients with high risk or diagnosed for the colorectal malignancy should indicate for the whole-­ wheat intake. An open question arises, whether these patients should remarkably increase the products of the whole-wheat intake for other food items. Presumably, no clinical trial has so far conducted to answer this issue.

The studies included a wide age range of 30–76. More than 5 studies conducted in the US, >7 in Scandinavia, >3 in the rest of Western Europe and only 1 in China. In the study conducted in China, the highest effect has shown with a relative risk of 0.48. According to wide epidemiological and observational studies, the risk of colorectal cancer strictly related to the lifestyle, especially to the diet and physical activity. For many years, the researchers have taken advantage of the fact that colorectal carcinogenesis is a stepwise process, lasting several years, since its beginning as a single mutational event in a cell, until the detectable malignancy observed. Colorectal cancer ranks in all other cancer cases with the second incidence in women and the third in men and. The death rate is ~75% in people >65 y, with mortality higher in males. There are high differences in the incidence of colorectal cancer across countries that mainly attributed to the diet. Most of the colorectal cancer cases, ~75%, are not hereditary and occur spontaneously, while the remaining 25% of the affected individuals have a family history, which shows the combined contribution of genetics and the environmental factors. There is a prediction that 90% of the gastrointestinal cancers are due to differences in the diet while a diet rich in fiber is associated with a lower risk of the developing colorectal cancer (Encarnação et al. 2015; Roncucci and Mariani 2015; Nistal et al. 2015). The colorectal cancer is a complex disease with a variable clinical course and with important divergences in the response to the treatment. The most plausible explanation for this erratic behavior may reside in the strong h­ eterogeneity. Each cancer cell shows important dissimilarities regarding the remaining cells due to the presence of the different genetic and biological alterations. The tumors considered as highly dynamic entities, subjected to the intense evolutionary pressure, in which the cell composition, the biological phenotype, and the clinical characteristics are continually evolving (Blanco-Calvo et  al. 2015). Despite the dietary recommendations to increase the whole-grain intake, little research was conducted on the physiological effects of the diets high in the whole-grains. There is substantial scientific evidence suggesting that the whole-grains as commonly consumed in the US and Europe reduce the risk

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of cancer (Slavin 2000). The association between the higher intake of the wholegrains and the reduced risk of the disease is one of the most consistent findings in the nutritional epidemiology. The consumption of the dietary fiber of the wholewheat alone does not fully explain the frequent association between the higher intake of the whole-grains and the reduced risk of the disease in observational studies. The second constituent is the phytochemicals of the wheat kernel with their capacity to induce many alleviative effects in our organism (Ross 2015). In the colon, two of the whole-wheat ingredients namely the dietary fiber and the bound or the conjugated polyphenols are presumably exerting the favorable outcomes. Some explanation for the encouraging effect of the whole-wheat in the human colon: (a) When we consume the whole-wheat bread as the main energy source we double (and might more than double) the total dietary fiber intake and thus the whole-­ wheat dietary fiber comprises ~0.5 of the total dietary fiber which is the highest one among all food items consumed (Slavin 2000; Reicks et al. 2014). (b) Among other effects, the dietary fiber increases colon microbiota that induces the immune system. We assume that such induction of the immune system has a marked effect on the colorectal incidence. (c) When we consume the whole-wheat bread, we increase by ~twofold the dietary anti-oxidant intake. However, while most of the polyphenols in the fruits and vegetable are free compounds, the vast majority of wheat polyphenols appear as bound forms. The free polyphenols absorbed at the upper intestine with a limited effect on the colonocyte. The bound polyphenol released inside the colon with immediate action on the colonocyte and probably their activity preserved in all other tissues. (d) The wheat polyphenol released in the colon bounded to the bile acids in the colon and neutralize their toxic effects towards the colonocyte. (e) Except for the main anti-oxidant fraction of many polyphenols present in the whole-wheat, the whole-wheat flour contains many others ingredients which moderating the malignancy appearance such as, lignans, phytoestrogens, flavonoids, methyl donor compounds, and vitamins including the tocols. (f) The decrease in bile acids activity increases the colon water content, decreases the effect of the bile toxicity and moderate constipation. (g) The dietary fiber of the whole-wheat consists of high content of the resistant starch with a favorable effect on the colon microbiota and with a higher butyric acid production that has a particularly favorable effect on the colonocyte. (h) The moderating of constipation decreases the diverticula appearance and thus decreases the bile acid hydroxylation. The hydroxylated bile acids are the more toxic compounds that enhance the malignancy incidence. (i) The decrease in the digesta transit time through the colon decreases the bile hydroxylation by the microbial activity while hydroxylated bile acids are more toxic with a higher rate of malignancy induction than the effect of the primary bile acids. The incidence of colorectal cancer is the highest in Western countries and presumably related to dietary habits. While the incidence of colorectal cancer related to

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the genetic determinants in many studies (Blanco-Calvo et  al. 2015), the dietary factors modulate the genetic susceptibility. With the most restricted capability to modulate the genetic determinants, the dietary ingredients should be the immediate target of the management of the colorectal malignancy. In the epidemiological observations, migrant studies revealed that the inhabitants moving from the low-­ incidence to the high-incidence areas acquired the colonic cancer risk of the region they have moved. Within a given high-risk population, the groups with different lifestyles have different colon cancer risks (Nagengast et al. 1995). Colorectal cancer has a typical age-related morbidity (Fig. 15.1). However, the burden developed within years and many cases observed at the advanced age after the disease has started decades ago. Whole-wheat intake has a remarkable effect on the decrease in colorectal incidence. The colorectal cancer is a major morbidity of the large intestine and a leading cause of the cancer deaths in the US (Nomura et al. 2007) and in many other countris (Jacobs et al. 2007b). Colorectal cancer hypothesis has long held an attraction for both the medical researchers and the public health authorities whether the intake of the dietary fiber can protect against colorectal cancer (Schatzkin et al. 2007). The 5-y survival of colorectal cancer in Europe is ~54% that is somewhat above the all site cancer survival of 52% (Berrino et al. 2007). In the US at the age of 50, the incidence is 1.66 M subjects, the alleviative effect of the fruit and vegetable on the decrease in the incidence of the colorectal cancer was not proved as well as in other studies (Michels et al. 2000; Otani et al. 2006; Hung et al. 2004; Fuchs et al. 1999). This issue has focused by some reviews and editorials in recent years (Ferguson and Harris 2003, 2005; Ferguson 2005; Boyle and Leon 2011; Nakaji et al. 2003; Tan 2015). The awareness of the caregivers in the health system towards the necessity to consume reasonable amounts of the dietary fiber is not self-­evident. One generation ago, the dietary fiber was termed roughage or straw (Ferguson 2005. Even today, many physicians and other caregivers do not recount the dietary fiber as a major macronutrient.

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According to one opinion, the doubling of the dietary fiber intake could reduce the risk of colorectal cancer by 40% (Bingham et al. 2003) in a population with low fiber intake. Disregarding of the well-known recommendation to consume about 400 g of vegetable and fruit or 5 servings a day may result in a major catastrophic decline in public health. Relative risk at a range of 0.7–0.8 for colorectal cancer estimated for proper intake of dietary fiber versus very low intake of dietary fiber. Intake of the whole-grain bread for refined-flour bread has a remarkable effect on the total diet content of the dietary fiber. With the knowledge acquired for the advantage of the whole-wheat intake and its specific ingredients in the lessening of many morbidities and other health burdens, a wide room has opened for the targeted wheat breeding that the intake of such a product might release the specific burden. The colorectal cancer might be one of the more attractive opportunity for such a notion of breeding brand name wheat for the lessening of the colorectal cancer because of the relative high prevalence of the colorectal cancer, because of the robust data accumulated for the whole-wheat effect, and because of the high conscious of the public to the occurrence of colorectal cancer. The extreme high consumption of the refined wheat in Europe and the US shows us that the notion of the preferred whole-wheat intake should get a major priority in the nutritional education and the activity of the nutritional regulators. While consumption of the whole-wheat bread is a general recommendation for the general population, colorectal patients distinctively lay at a different category. Physicians should indicate their patients who mutilated by the colon cancer to consume whole-wheat bread and other whole-wheat products. Increase in the whole-wheat consumption for other items with high energy content, and in particular, the high-fat content might be an additional measure to decrease the risk of colorectal cancer. While no restrictions or objection foresaw for strong recommendation to indicate the intake of the whole-wheat bread for the refined wheat products further measures should attain some additional support.

 he Incidence of the Upper Gut Malignancy (Table 15.1, T Category 2) In four epidemiological studies with 0.5 M subjects, an average impressive relative risk of 0.58 (Table 15.1) with a range of 0.49–0.71 between studies is presented. A rare incidence has reported for the cancer of the small intestine. In the US, the incidence of the small intestine cancer lower by ~30 fold than that of colorectal cancer even though the small intestine comprises 75% of the human alimentary tract. Studies for the effects of the whole-grain on the small intestinal cancer are sparse and many of them are case-control designed. The studies conducted in the

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US in both genders with a wide age range (29–85 y). However, in the US the upper gut malignancy is one of the burdens with a steep increase in the incidence at age >80. The same trends observed also in the Israeli population (Fig.  15.1). In the colon, the whole-grain intake increases the fecal bulk, improves the microbiota population, decreases the colon transit time, increases the butyrate production, and decrease the bile acid hydroxylation. Some direct effects, such as phytic acid and anti-oxidants, might prevent the development of the small intestine cancer, but such substances still trapped within the dietary fiber particles on their travel in the small intestine. The major alleviative activity of the whole-grain probably produced by another mechanism, not described yet, which might also be active in the colon and other organs. Because the polyphenols that released in the colon arrive at all tissues, the upper-gut malignancy might be affected by whole-wheat activity in the colon. However, no evidence has claimed for such an activity.

 he Incidence of the Pancreatic Malignancy (Table 15.1, T Category 3) In three epidemiological studies with 50 K subjects, an average relative risk of 0.7 (Table 15.1) with a range of 0.60–0.76 is presented. The studies conducted in the US and Western Europe in both genders with a wide age range of 21–85 y. The pancreatic carcinoma is the fourth leading cause of cancer-related death worldwide. This cancer has a poor prognosis and documented for the survival of 1 y. The poor survival for pancreatic cancer also related to the lack of the symptoms that result in the patients with the advanced disease presenting late, frequently with metastatic disease. Unlike many tumors where significant advances have made and new treatment modalities developed, conventional and targeted therapies for pancreatic cancer consistently fail to produce the anticipated progress and promising basic research does not translate into the clinical setting (Haqq et al. 2014). Several studies have suggested that diets high in fiber, low in glycemic load, or high in whole-grains may confer some protection against pancreatic cancer. Several plausible biologic mechanisms have hypothesized to underlie these associations, including the beneficial effects of the fiber, whole-grains, or low-glycemic-load diets on insulin resistance, triglyceride levels, and the high-density lipoprotein (HDL) levels.

In many studies that have cited in this book and many additional articles that have not cited here, the effect of dietary fiber intake on the morbidities and the mortality has presented almost like a major nutritional factor. In many studies, the dietary fiber stands as an independent factor for the evaluation of its effects on the relative risks for morbidities. However, the high intake of dietary fiber is highly correlated with the high intake of the antioxidants. Presently no technology and no methodology available for the distinction between these two

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groups of ingredients. The dietary fiber content is much higher than that of the antioxidants while dietary fiber content in the dry matter may reach ~10% the content of the antioxidant lower by 1000 fold. The absence of the antioxidant content from all known Food-Tables is probably a serious drawback in the evaluation of the antioxidants in their role for the decrease in the morbidities. The main reason for such a major drawback is presumably the absence of a consensual and accepted official method for the measurement of the total antioxidant capacity. Additional information to the data presented for the whole-wheat has published in a meta-analysis of 14 case-control studies for the effect of each of these effects may influence directly the pancreatic cancer risk or interact with other factors. Identifying modifiable risk factors to prevent pancreatic cancer could have a substantial public health impact, as pancreatic cancer is the highest fatal cancer in the US. The data for the pancreatic cancer (Table 15.1) support for the hypothesis that whole-grain foods and fiber may protect against pancreatic cancer (Chan et  al. 2007) with the high versus low fiber intake with the calculation of relative risk of 0.52 (Wang et al. 2015). Some of the studies conducted in China and Japan but most of them in North America and Europe. In subjects with high fiber intake, in the Westernized countries, the main mass of the dietary fiber derived from the wheat fiber. Therefore, we assume the main effect of the reduction in pancreatic cancer produced by the dietary fiber derived from the wheat fiber and the escorted compounds. However, no specific effect of the wheat fiber on pancreatic cancer has calculated. Therefore, these data could not incorporate into the general presentation of the effect of the whole-wheat intake on the various burdens (Table 15.1).

The Incidence of Breast Cancer (Table 15.1, Category 4) In four epidemiological studies with 3.9 M subjects, an average relative risk of 0.80 (Table 15.1) with a range of 0.49–0.91 between studies presented. The studies conducted in the US and Greece. Breast cancer is the most common cancer in women worldwide. The disease places a considerable burden on the patients and the healthcare systems. Nevertheless, progress has made in the treatment of the breast cancer in the Western world over the past three decades while 5-y relative survival rates in Europe increasing from 73% to 83% between 1992 and 2008 (Leo et al. 2015). In many studies, the high whole-wheat intake (versus the low intake) failed to show an advantage of a decrease in the incidence of breast cancer. With the menu contains high-intake of the whole-wheat this fraction comprises the main content of all dietary fiber in the daily menu. Researchers making the distinction for the wheat fiber consider such a distinction might explain the effects of

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the outcomes. Presumably, the distinction between the cereal dietary fiber versus other sources of the dietary fiber is the most important because of the long list of the anti-oxidants bound to the wheat dietary fiber. The total dietary fiber measure has a major disadvantage while it includes a considerable amount of the dietary fiber derived from potato. In most of the dietary questionnaires, the potato intake counted as the vegetable content while the alleviative effect of the potato intake is questionable. The findings in a large prospective study support the hypothesis that the consumption of foods high in fiber reduces breast cancer risk (Farvid et al. 2016b). The high fiber might affect the absorption of the steroids hormones. The sex steroid hormone levels, strongly related to the breast cancer expansion, and a diet high in fiber has hypothesized to reduce the breast cancer incidence by inhibiting the reabsorption of the estrogen, thus decreasing circulating levels (Rose et al. 1991). Major support for the ability of the whole-wheat intake to reduce the incidence of the breast cancer shown in comparatively small study comprised 16 breast-cancer patients and 20 controls conducted in Finland. Cereal dietary fiber intake was 8.1 versus 10.6 g/d, plasma alkylresorcinol concentrations were 142 versus 200 nM and the urinary alkylresorcinol excretion was 48 versus 68 μmol/d respectively with the highly significant differences. The plasma and the urinary alkylresorcinol are excellent biomarkers for the whole-grain intake, which mainly present in wheat, and rye. Such biomarkers are much more accurate than the data extracted by the dietary questionnaires. The women at risk for breast cancer consume significantly lower amounts of rye and whole-grain wheat cereal fiber. Even in this small-scale study, the researchers have succeeded to show a very high significant difference in the whole-grain intake between breast cancer patients and the controls (Aubertin-­ Leheudre et al. 2010). However, again and again, the scholars repeating the slogan of the dietary fiber as the only alleviative ingredient for the whole-grain effect without mentioning of the anti-oxidants and the other phytochemicals that present in the whole-grain. Unfortunately, such disregarding most common in many of the articles describing the alleviative effect of the whole-wheat.

 he Incidence of the Ovarian Malignancy (Table 15.1, T Category 5) Ovarian cancer is the second most common female reproductive malignant tumor and because the majority of new ovarian cancer cases are diagnosed at an advanced stage the disease is the leading cause of gynecological death in US women. Even the ovary cancer is a leadin burden in women, the studies that tried to show the dietar effect on the incidence of the disease are still limited and inconsistent (Crane et al. 2013; Zheng et al. 2018).

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 he Incidence of the Hepatocellular Carcinoma (Table 15.1, T Category 6) Primary liver cancer is the sixth most commonly occurring cancer and the second leading cause of death from cancer worldwide with an increasing incidence rate the last 40 y (Yang et al. 2019). The alleviative effect of the whole-wheat intake has primarily attributed to the dietary fiber embedded in the wheat kernel. Again and again, the polyphenol content and the other anti-oxidant ingredients of the whole-­ wheat kernel does not consider. Screening of the studies for the hepatocellular carcinoma and polyphenols shows preventive effects of the natural foods and a long list of polyphenol ingredients (Zhang et  al. 2017, 2019; Sun et  al. 2016; Liao et  al. 2015). Because the vast majority of the polyphenol content of the wheat kernel is present with the bound compounds, the current methodologies to show the anti-­ malignant capacity of the wheat kernel fails to show positive effects.

 he Incidence of the All-Cause of Malignancy (Table 15.1, T Category 7) In >5 of epidemiological studies with >770 K subjects, the average relative risk of 0.77 (Table 15.1) with a range of 0.79–0.89 between studies presented. The relative risk of all-cause malignancy is an attractive parameter with presumably more impressive value to describe the effect of the whole-wheat bread than many other parameters for the relative risk. The wide gap between the various countries in the prevalence of non-communicable diseases enables us some better evaluation to inquire about the causes of these morbidities. Within the top 50 screened countries (Denmark, France and Australia) the prevalence of all-cause of cancer is about 325 per 100,000 inhabitants while for the lowest 3 countries (Japan, Argentina, and Puerto Rica) the prevalence is 215 per 100,000 (World Cancer Research Fund). The relative risk for all-cause malignancy might be a more suitable parameter for the evaluation of the populations for their relative risks.

 he Incidence of Cardiovascular Morbidity (Table 15.1, T Category 8) In nine epidemiological studies with 2.9 M subjects, an average relative risk of 0.78 (Table 15.1) with a range of 0.56–0.90 between studies presented. The studies conducted in both genders with a wide age range of 25–98 y. The large-scale epidemiological outcomes are the most authoritative source for the evaluation of nutritional status and elicit optimal nutrition. Presumably, the suboptimal diet is the leading risk factor for death and disability worldwide. In comparison with the ­historical

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dietary recommendations that largely based on cross-national studies, short-­term experiments, and animal models, nutrition science has transformed in the past two decades by more rigorous evidence from well-designed metabolic studies, prospective cohorts, and randomized clinical trials. The atherosclerosis is the leading trigger of mortality in the high-income countries, causes at least 30% of mortality by ischemic heart disease, cerebrovascular disease and vascular dementia (Lopez et al. 2006). Within a long period, the effect of the dietary fiber on the morbidity and the mortality evaluated as a global effect. However, not all the dietary fiber sources have similar activity on health status and even the dietary fiber of vegetables and fruits is not a homogenous ingredient. Some fruits and vegetable items have shown to exert no positive effect on cardiovascular morbidity and mortality. The increase in the whole-grain intake showed a clear decrease in coronary heart disease with a significant relative risk of 0.78 while the effect of fruit fiber was smaller and not significant. The increase in the intima-media thickness of the carotid may relate to the low fiber intake. The analysis of the effect of dietary fiber derived from the whole-grain on morbidity and mortality may bias by the intake of other food items. The whole-grain fiber was positively associated with the intake of fruits and vegetables and associated with the intake of fish and other known factors of lifestyle (Mozaffarian et al. 2014). In two studies, the relative risk of atherosclerosis was below 0.7 in subjects consumed 5 vs 1 serving/d of whole-grain or fruit and vegetable. Probably much fewer data have published for the effect of dietary fiber on atherosclerosis than that published for the effect on colorectal cancer but for atherosclerosis, no extensive discrepancy presented.

The Incidence of Stroke (Table 15.1, Category 9) In nine epidemiological studies with 3.0 M subjects, an average relative risk of 0.81 (Table 15.1) with a range of 0.69–0.94 between studies presented. The studies conducted in the US and Western Europe in both genders with a wide range of ages, 30–84  y. Although stroke-related mortality has declined since the mid-twentieth century, incidence rates of stroke have been level since the mid-1980s, and stroke remains a leading cause of serious disability and death in women in the US with a higher rate in females than males. The rates of age-adjusted stroke mortality and disability-adjusted life years lost were higher in low-income countries than in the middle-income or high-income countries. Improving diet and lifestyle are critical for stroke risk reduction in the general population. The effect of higher consumption of whole-grain on the risk of ischemic stroke was independent of a variety of other coronary vascular diseases. The apparent inverse relationship between whole-grain intake and risk of ischemic stroke was remarkably consistent among subgroups of women who were never smokers, did not drink alcohol, did not report regular vigorous physical activity, or did not use postmenopausal hormones. The protective effect of whole-grains against ischemic stroke may involve multiple biological pathways. Whole-grains contain an

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abundance of anti-oxidants, minerals, phytochemicals, and fibers in both the outer (bran) and inner (germ) layers, both of which removed during processing of refined flour (Liu et al. 2003; Fang et al. 2015). The case-control study conducted in the Department of Neurology, People’s Hospital of Shenzhen, Guangdong, China in 990 stroke patients and similar control is a most interesting study (Sun et al. 2019). In all subjects, the plasma DHPPA was measured as a biomarker for the alkylresorcinols intake (because of a longer half-­ life than that of the alkylresorcinols. The alkylresorcinol is a known biomarker for the whole-grain intake either wheat and rice (Chap. 17). In this study, a low relative risk of 0.65 was calculated for the highest quintile of the plasma DHPPA in comparison to the lowest quintile. The association remained unchanged after adjustment for key risk factors for stroke and was generally consistent across different subgroups, suggesting a robust relation between plasma DHPPA and ischemic stroke. Significantly lower concentrations of plasmaDHPPA were also found in ischemic stroke cases compared with controls with a ratio of 1.3 between case and controls in the first quartile and a ratio of 0.8 in the fourth quartile of the plasma DHPPA.

The Incidence of Hypertension (Table 15.1, Category 10) In three epidemiological studies with 62 K subjects, an average relative risk of 0.81 (Table 15.1) with a range of 0.77–0.84 between studies presented. The studies conducted in the US and Iran in both genders with an age range of 18–74 y. High blood pressure is a major risk factor for cardiovascular disease and stroke. Untreated blood pressure of >120/>80 mm Hg (systolic and diastolic blood pressure SBP/DBP) for adults aged ≥20 y, defined as 1 of the 7 components of ideal cardiovascular health. In the US in 2012, 82% of children and 42% of adults met these criteria. For the surveillance purposes, the following definition of high blood pressure has proposed:  – SBP  ≥140  mm Hg or DBP  ≥90  mm Hg. With this definition, the prevalence of hypertension among US ≥20  y estimated to be 33% in the National Health and Examination Survey (NHANES) 2009–2012). Hypertension is the leading modifiable cause of mortality worldwide (Mozaffarian et al. 2015). Three studies (Table 15.1) show that the high intake of the whole-wheat caused a consistent reduced risk of hypertension. The association is a dose-related and independent of known risk factors for hypertension. The quantitative estimates of intake suggest that added bran is a relatively small component compared with the total whole-­wheat and cereal fiber intakes. These findings have implications for future dietary guidelines and the prevention of hypertension (Wang et al. 2007). In an evaluation of the two studies comprised of 60 k subjects, an increase of 30 g of whole-grain/day showed to reduces the hypertension incidence by 4.0 cases/1000 person/y and a 40 g increase in whole-grain intake drop the incidence by 5.4 cases/1000 person/y (Lillioja et al. 2013). In another study, an intake of 200 g/d of whole-wheat bread in normotensive subjects within 3 wks period resulted in a significant decrease in systolic blood pressure (Bodinham et al. 2011).

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The Incidence of Diabetes Type 2 (Table 15.1, Category 11) In >13 epidemiological studies with >2.3  M subjects, an average relative risk of 0.74 (Table 15.1) with a range of 0.64–0.88 between studies presented. The studies conducted in both genders with an age range of 18–79 y. The global prevalence of diabetes in 2014 estimated to be 9% among adults (>18 y) with considerably more young people now also developing diabetes. Diabetes generally refers to type 2 while the prevalence of Type 1 in the US is ~0.3% and defined if they started insulin within 1  y of diabetes diagnosis, and were diagnosed with diabetes at age 20 and low fiber diet 50 g/d) was found to reduces glycemia in subjects with diabetes type 1 and glycemia, hyperinsulinemia, and lipemia in subjects with diabetes type 2 (Bantle et al. 2006). Lower values of glycemic load were observed for bread intake (whole-bread) with 7.3% fiber for other four bread types with 3.3–4.3% fiber in a restricted study of 23 male and female, aged 32, conducted in Granada (Gonzalez-Anton et al. 2015). According to the meta-analysis of 14 studies, the consumption of whole-grain foods may improve acutely the postprandial glucose and insulin homeostasis compared to the similar refined foods in a healthy subject (Marventano et  al. 2017). Breeding of wheat-bread with a lower decomposition rate of the starch by the increase in all or specific content of the antioxidants may produce a superior bread with a lower glycemic index for diabetic patients or the people with a Pancreatic α-amylase and intestinal α-glucosidase are the two key enzymes involved in starch digestion. The starch hydrolyzed by amylases to α-dextrins or oligosaccharides (maltose, maltotriose, Fig. 6.4) that are further hydrolyzed to glucose by the intestinal α-glucosidase before being absorbed in the duodenum and the upper jejunum. Starch and starchy food products classified based on their digestibility. Post-meal glycemic control in type 2 diabetics due to ingestion of starchy food is of great interest in the context of the worldwide health concerns. An important therapeutic approach for treating type 2 diabetes is to decrease the postprandial hyperglycemia by retarding the absorption of glucose through the inhibition of the enzymes, α-amylase, and α-glucosidase, in the digestive tract. Enzyme inhibitors delay the rate of the glucose absorption by preventing the carbohydrate digestion and consequently dulling the postprandial plasma glucose rise. The inhibition of the starch digestive enzymes by the synthetic agents, such as acarbose, is an important clinical strategy for controlling postprandial glycemia. The phenolic compounds have received much attention for controlling the digestibility of starch and for having a high anti-oxidant activity. They are widely distributed in plant foods and in particular in the whole-wheat flour. Their biological activities depend on their chemical structures, doses, and time of consumption.

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In a cross-sectional survey with a nationally representative study of boys and girls, 12–19 y, in the US population (National Health and Examination Survey – NHANES study), n = 5000, high intake of whole-grain versus null was negatively associated with a significant decrease in fasting insulin level 12.1 vs 13.4 μIU/m (Hur and Reicks 2012).

The Incidence of Metabolic Syndrome (Table 15.1, Category 12) We locate one epidemiological study with 1 K subjects with relative risk of 0.46 (Table 15.1). The study conducted in Massachutches in both genders ages, >60 y. The metabolic syndrome is a complex disorder represented by a cluster of cardiovascular risk factors related to central fat distribution and insulin resistance. These risk factors include dyslipidemia, central obesity, changes in blood glucose homeostasis and hypertension. The prevalence of metabolic syndrome in the overall population is approximately 24%, reaching more than 80% among patients with type-2 diabetes mellitus. Metabolic syndrome is an important risk factor for early mortality in non-diabetic individuals and patients with type-2 diabetes mellitus. The World Health Organization set the following definition for the metabolic syndrome: (a) The presence of hypertension, mmHg: ≥140/90; (b) BMI: ≥30; and or waist/hip >0.90 M; >0.85 F; (c) The presence of micro- or macroalbuminuria, μg/min: ≥20; (d) Triglycerides, mg/dL: ≥150; (e) HDL cholesterol, mg/dl: 50 y and the incidence of hip fracture are escalating worldwide. Diet is one of the important modifiable risk factors that can influence bone mass, bone strength, and subsequent fracture risk. Various nutrients and dietary components have suggested as having favorable impacts on maintaining bone health and reducing the risk of osteoporotic fractures (Dai et al. 2014). The information for the effect of whole-­wheat consumption is limited presumably because whole-wheat intake correlated with the intake of vegetable and fruits. The remarkable content of the phytic acid in the whole-wheat products have attracted some researchers to inquire whether whole-wheat might have an aggregative effect on osteoporosis and hip fracture.

 he Incidence of the Mortality Attributed to Malignancy T (Table 15.1, Category 14) In >9 epidemiological studies with >3.7 M subjects, an average relative risk of 0.86 (Table 15.1) with a range of 0.75–0.94 between studies presented. The studies conducted in both genders with an age range of 16–98 y. The relationships between the whole-grain intake and the mortality incidences described in some studies. An association of the whole-grain intake with reduced risk for several chronic diseases is biologically reasonable because of the high nutritional quality of whole-grain; the great bulk of nutrients and the biologically active constituents in grain found in the bran and the germ (Jacobs et al. 2001). Reviews of case-control studies have shown a consistently reduced risk of cancer for high vs low intake of whole-grain foods and suggested a corresponding increased

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risk for high vs low intake of refined grains. Reviews of 40 case-control studies of whole-grain intake investigating 20 different cancers found consistently reduced risk in high vs low consumers of whole-grain foods. The earlier reviews suggested the opposite for refined grain foods, with consistently increased cancer risks in the published case-control studies of individuals with high vs low intakes of refined grain (Jacobs et  al. 1999). A significant inverse association found between total whole-grain intake and risk of mortality from total cancers. This finding is consistent with a meta-analysis of prospective cohort and nested case-control studies that documented that 10 g/d cereal fiber was associated with a 10% reduction in risk of developing colorectal cancer and an increase of 3 servings/d of whole-grains that was related to a 17% reduced risk of colorectal cancer (Benisi-Kohansal et al. 2016).

 he Incidence of Mortality Attributed to Cardiovascular T Diseases (Table 15.1, Category 15) In >17 epidemiological studies with 5.5 M subjects an average relative risk of 0.76 (Table 15.1) with a range of 0.48–0.84 between studies presented. The studies conducted in both genders with an age range of 16–98 y. The inverse association with coronary vascular diseases mortality did not vary by sex, study location, follow-up duration, and energy adjustment. The meta-analysis of the highest vs the lowest level of cereal fiber intake has used to demonstrate the potentially important biological effects. Besides the general effect of the whole-grain intake also a linear association found between cereal fiber intake and mortality (Hajishafiee et al. 2016). The results of the studies gathered here were in line with existing findings linking whole-grain intake with the risk of coronary vascular diseases, as well as other cardiometabolic conditions such as type 2 diabetes mellitus and with the general recommendation of whole-grain intake (Zong et al. 2016). In many of the studies, the examined population contained wide segments of subjects in the age range of 16–45 y. At this age range, in a normal population, the incidence of cardiovascular disease is very low as well as the mortality occurrence. Schematic incorporation of all population range decreases the effect of the examined nutritional effect and also decreases the statistical significance.

 he Incidence of the Mortality Attributed to Stroke (Table 15.1, T Category 16) In two epidemiological studies with >120 K subjects an average relative risk of 0.87 (Table 15.1) presented. The studies conducted in both genders with an age range of 30–64 y. The effect of the whole-grain intake on the decrease of mortality caused by stroke found quite consistently for different causes of death and across genders and

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types of products of whole-grain. The intake of the whole-grain is an important aspect of diet in preventing early death, and there were no indications that the associations between whole-grain and mortality were caused by one specific type of product of whole-grain (Johnsen et al. 2015).

 he Incidence of the Mortality Attributed to Diabetes Type 2 T (Table 15.1, Category 17) In three epidemiological studies with 1.1 M subjects an average relative risk of 0.82 (Table 15.1) with a range of 0.54–1.28 between studies presented. The studies conducted in both genders with an age range of 30–71 y. The incidence of mortality for coronary vascular disease is much higher in patients diagnosed with diabetes type 2 as reported in Sweden and Glasgow studies (Alabas et al. 2016; Kristensen et al. 2016) and many other studies. In a study with 57 k subjects, aged 50–65 y, conducted in Copenhagen and Aarhus area a consistent association found between the high whole-grain intake and the lower risk of type 2 diabetes (Kyrø et al. 2018).

 he Incidence of the Mortality Attributed to Inflammatory T Diseases (Table 15.1, Category 18) In >5 epidemiological studies with 1.06 M subjects an average relative risk of 0.76 (Table 15.1) with a range of 0.65–0.83 between studies presented. The studies conducted in both genders with an age range of 46–71 y. Prospective epidemiological data provide a reasonable body of evidence pointing towards a modest effect of whole-grains to reduce markers of subclinical inflammation, especially circulating CRP concentrations. However, results from the epidemiological studies should interpret with caution, given that definition used to define whole-grain foods that differ substantially across studies (Lefevre and Jonnalagadda 2012). Among 15 phenolic acids monitored in serum, urine, and feces, an 8-wk consumption of whole-­ grain resulted in a significant increase in urinary and fecal ferulic acid and serum dehydroferulic acid concentrations. The observation that ferulic acid concentration can increase in the blood on whole-wheat consumption was conceptually in agreement with a previous study, conducted in healthy normal-weight subjects. In subjects at high risk of developing chronic diseases (because of obesity and unhealthy lifestyle), the modification of the dietary habits alone can boost a positive immune response. The replacement of the refined wheat products with whole-grain products, thereby possibly reducing the risk of developing obesity-related diseases over the long term. Wheat ferulic acid released and absorbed in the gut and likely metabolized by gut microbiota. Dehydroferulic acid is the most abundant circulating metabolite in

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overweight/obese subjects. Amelioration of individual inflammatory status found in the context of controlled energy and nutritionally balanced replacement of refined wheat with whole-wheat products, and not accompanied by a modification of body weight. Data on inflammatory markers have shown a significant reduction of inflammatory tumor necrosis factor-a (TNF-α)) and a trend toward reduced (interleukin) IL-6 after 8 wks, as well as an increase of the anti-inflammatory IL-10 after 4 wks of whole-grain consumption. Two previous intervention trials demonstrated the ability of whole-grain consumption to ameliorate subclinical inflammation (Vitaglione et al. 2015). Phenolic acids have anti-inflammatory properties that are potentially significant for the promotion of gastrointestinal health complexity of studying their biological effects. A significant reduction of pro-inflammatory cytokines in humans also ascribed to phenolic compounds. In vitro study revealed the potential anti-­ inflammatory activity of phenolic acids from the whole-meal flour of durum and common wheat. In particular, the anti-inflammatory activity of phenolic compounds shown in human colon cells, suggesting the potential role of these wheat components in intestinal good health (Laddomada et al. 2015). A higher intake of carbohydrates from food sources with a higher glycemic index and lower consumption of whole-grain during puberty, prospectively predict greater IL-6 (a pro-inflammatory marker) concentrations in young adulthood. Among adults, most observational studies also reported reduced low-grade inflammation among those consuming whole-grain and dietary fiber, although the evidence is less consistent in intervention studies (Goletzke et al. 2014). Higher intake of whole-wheat bread (fifth quintile ~100 versus first quintile with ~2.5  g/d) associated with a decrease of inflammatory markers namely C-reactive protein (CRP) and γ-glutamyltransferase (GGT). An opposite trend observed with the red-meat intake (Montonen et al. 2013).

 he Incidence of the Mortality Attributed to Respiratory T Diseases (Table 15.1, Category 19) In >3 epidemiological studies with 1.1 M subjects an average relative risk of 0.72 (Table 15.1) with a range of 0.64–0.71 between studies presented. The studies conducted in both genders with an age range of 30–71  y. We could not find some explanatory support for the effect of whole-wheat products except the general effects such as immune induction. The lung exposed not only directly to the higher O2 tensions and environmental oxidants, but also to oxidants that produced by the variety of lung diseases and in the course of their therapies. If these oxidant compounds not scavenged, the delicate epithelial cells that line the respiratory tract would undergo free radical damage, characterized by an increase in the oxidation of cellular lipids, proteins, carbohydrates, and DNA. As a consequence, there is an increase in impaired cellular functions and enhanced inflammatory reactions. To counteract the oxidative threat, the

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lungs endowed with the anti-oxidant defense system. The first and probably the most important line of defense against inhaled environmental oxidants and endogenous inflammatory–immune oxidant products is a thin, highly-complex and heterogeneous layer of lining fluid (the respiratory-tract lining fluid) that covers the respiratory epithelium. It has a unique armamentarium of anti-oxidants, at a high concentration, including vitamin C, urate, reduced glutathione, vitamin E, and extracellular superoxide dismutase, catalase, and glutathione peroxidase. Additional anti-oxidants include mucopolypeptide glycoproteins and small molecules such as bilirubin. In the normal lung, complex and coordinated interactions of anti-oxidant compounds provide adequate protection of the distal lung structures from the damaging effects of the oxidative attack. However, an imbalance between the production of oxidants and anti-oxidant capacity leads to the state of oxidative stress. The particular low relative risk of 0.72 (Table 15.1) of the whole-wheat intake for the respiratory diseases might produce by the high oxygenation in the lung tissue (Kelly 2005).

 he Incidence of the All-Cause of Mortality (Table 15.1, T Category 20) In >13 epidemiological studies with 4.8 M subjects an average relative risk of 0.80 (Table 15.1) with a range of 0.64–0.86 between studies presented. The studies conducted in both genders with a ages range of 16–98 y. A large prospective cohort study conducted in the US population, high consumption of whole-grains or cereal fiber significantly associated with reduced risk of all-cause mortality and death from coronary vascular diseases, cancer, diabetes, respiratory disease, infections, and other causes. As compared with individuals with the lowest intake of whole-grains, those in the highest intake group had a 17% lower risk of all-cause mortality and 11–48% lower risk of disease-specific mortality. As compared with individuals with the lowest intake of cereal fiber, those in the highest intake group had a 19% lower risk of all-cause mortality and 15–34% lower risk of disease-specific mortality. The results suggested that the protective effects of whole-grains might due, at least in the main part, to its cereal fiber component. The findings are concordant with the previously observed protective effects of whole-grain intake on CVD, diabetes, and certain cancers. A 2 servings/d increment in whole-grain consumption associated with a 21% decrease in risk of type 2 diabetes (Huang et al. 2015). In these collected studies, subjects at the age group of 16–45 y have included. As for Category 14 above, we commented on the disadvantage of such design of the studies. The association of the whole-grain bread intake with the mortality incidence mainly attributed to cardiovascular diseases, followed by the cancers. The association of the whole-grain intake with the reduced risk for several chronic diseases is biologically reasonable because of the high nutritional quality of the whole-grain, the great bulk of the nutrients and the biologically active constituents in the grain found in the bran and the germ (Huang et al. 2015; Jacobs et al. 2001, 1999).

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References Alabas OA, Hall M, Dondo TB, Rutherford MJ, Timmis AD, Batin PD, Deanfield JE, Hemingway H, Gale CP (2016) Long-term excess mortality associated with diabetes following acute myocardial infarction: a population-based cohort study. J Epidemiol Community Health 71:25–32. https://doi.org/10.1136/jech-2016-207402 AlEssa HB, Cohen R, Malik VS, Adebamowo SN, Rimm EB, Manson JAE, Willett WC, Hu FB (2018) Carbohydrate quality and quantity and risk of coronary heart disease among US women and men. Am J Clin Nutr 107:257–267. https://academic.oup.com/ajcn/article-abstr act/107/2/257/4911453 Aubertin-Leheudre M, Koskela A, Samaletdin A, Adlercreutz H (2010) Plasma and urinary alkylresorcinol metabolites as potential biomarkers of breast cancer risk in Finnish women: a pilot study. Nutr Cancer 62:759–764. https://doi.org/10.1080/01635581003693058 Aune D, Chan DSM, Lau R, Vieira R, Greenwood DC, Kampman E, Norat T (2011) Dietary fibre, whole-grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies. BMJ 343:d6617. https://doi.org/10.1136/bmj.d6617 Aune D, Norat T, Romundstad P, Vatten LJ (2013) Whole-grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Eur J Epidemiol 28:845–858. https://doi.org/10.1007/s10654-013-9852-5 Aune D, Keum N, Giovannucci E, Fadnes LT, Boffetta P, Greenwood DC, Tonstad S, Vatten LJ, Riboli E, Norat T (2016) Whole-grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies. BMJ 353:i2716. https://doi.org/10.1136/bmj.i2716 Bantle JP, Wylie-Rosett J, Albright A, Apovian CM, Clark NG, Franz MI, Hoogwerf BJ, Lichtenstein AH, Mayer-Davis E, Mooradian AD, Wheeler ML (2006) Nutrition recommendations and interventions for diabetes–2006: a position statement of the American Diabetes Association. Diabetes Care 29:2140–2157. https://doi.org/10.2337/dc06-9914 Barchana M, Liphshitz I, Rozen P (2004) Trends in colorectal cancer incidence and mortality in the Israeli Jewish ethnic populations. Familial Cancer 3:207–214. https://doi.org/10.1007/ s10689-004-9546-y Bates CJ, Lean MEJ, Mansoor MA, Prentice A (2004) Nutrient intakes; biochemical and risk indices associated with type 2 diabetes and glycosylated haemoglobin, in the british national diet and nutrition survey of people aged 65 years and over. Diabet Med 21:677–684. https://doi. org/10.1111/j.1464-5491.2004.01228.x Bechtholda A, Boeingb H, Schwedhelmb C, Hoffmannc G, Knüppelb S, Iqbalb K, Henauwd SD, Michelsd N, Devleesschauwere B, Schlesingerf S, Schwingshack L (2016) Food groups and risk of coronary heart disease, stroke and heart failure: a systematic review and dose-response meta-analysis of prospective studies. Crit Rev Food Sci Nutr 59:1071–1090. https://doi.org/10 .1080/10408398.2017.1392288 Ben Q, Sun Y, Chai R, Qian A, Xu B, Yuan Y (2014) Dietary fiber intake reduces risk for colorectal adenoma: a meta-analysis. Gastroenterology 146:689–699.e6. https://doi.org/10.1053/j. gastro.2013.11.003 Benisi-Kohansal S, Saneei P, Salehi-Marzijarani M, Larijani B, Esmaillzadeh A (2016) Whole-­ grain intake and mortality from all causes, cardiovascular disease, and cancer: a systematic review and dose-response meta-analysis of prospective cohort studies. Adv Nutr 7:1052–1065. https://doi.org/10.3945/an.115.011635 Berrino F, De Angelis R, Sant M, Rosso S, Lasota MB, Coebergh JW, Santaquilani M (2007) Survival for eight major cancers and all cancers combined for European adults diagnosed in 1995-99: results of the EUROCARE-4 study. Lancet Oncol 8:773–783. https://doi.org/10.1016/ S1470-2045(07)70245-0

336

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

Bingham SA, Day NE, Luben R, Ferrari P, Slimani N, Norat T, Clavel-chapelon F, Kesse E, Nieters A, Boeing H, Tjønneland A, Overvad K, Martinez C, Dorronsoro M, Gonzalez CA, Key TJ, Trichopoulou A, Naska A, Vineis P, Tumino R, Krogh V, Bueno-de-Mesquita HB, Peeters PHM, Berglund G, Hallmans G, Lund E, Skeie G, Kaaks R, Riboli E (2003) Dietary fibre in food and protection against colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC): an observational study. Lancet 361:1496–1501. https://doi. org/10.1016/s0140-6736(03)13174-1 Blanco-Calvo M, Concha A, Figueroa A, Garrido F, Valladares-Ayerbes M (2015) Colorectal cancer classification and cell heterogeneity: a systems oncology approach. Int J Mol Sci 16:13610–13632. https://doi.org/10.3390/ijms160613610 Bodinham CL, Hitchen KL, Youngman PJ, Frost GS, Robertson MD (2011) Short-term effects of whole-grain wheat on appetite and food intake in healthy adults: a pilot study. Br J Nutr 106:327–330. https://doi.org/10.1017/S0007114511000225 Boyle P, Leon ME (2011) Epidemiology of colorectal cancer. Br Med Bull 64:1–25. www.elsevier. com/locate/bmc Chan JM, Wang F, Holly EA (2007) Whole-grains and risk of pancreatic cancer in a large population-­based case-control study in the San Francisco Bay Area, California. Am J Epidemiol 166:1174–1185. https://doi.org/10.1093/aje/kwm194 Chandalia M, Garg A, Lutjohann D, Bergmann KV, Grundy SM, Brinkley LJ (2002) Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus. N Engl J Med 342:1392–1398. https://doi.org/10.1056/nejm200005113421903 Chanson-Rolle A, Meynier A, Aubin F, Lappi J, Poutanen K, Vinoy S, Braesco V (2015) Systematic review and meta-analysis of human studies to support a quantitative recommendation for whole-grain intake in relation to type 2 diabetes. PLoS One 10:e0131377. https://doi. org/10.1371/journal.pone.0131377 Chen H, Ward MH, Graubard BI, Heineman EF, Markin RM, Potischman NA, Russell RM, Weisenburger DD, Tucker KL (2002) Dietary pattern of the esophagus and distal stomach. Am J Clin Nutr 75:137–144 Chen GC, Tong X, Xu JY, Han SF, Wan ZX, Qin JB, Qin LQ (2016a) Whole-grain intake and total, cardiovascular, and cancer mortality: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr 104:164–172. https://doi.org/10.3945/ajcn.115.122432 Chen S, Chen Y, Ma S, Zheng R, Zhao P, Zhang L, Liu Y, Yu Q, Deng Q, Zhang K (2016b) Dietary fibre intake and risk of breast cancer: a systematic review and meta-analysis of epidemiological studies. Oncotarget 7:80980–80989. www.impactjournals.com/oncotarget Cho SS, Qi L, Fahey GC Jr, Klurfeld DM (2013) Consumption of cereal fiber, mixtures of whole-­ grains and bran, and whole-grains and risk reduction in type 2 diabetes, obesity, and cardiovascular disease. Am J Clin Nutr 98:594–619. https://doi.org/10.3945/ajcn.113.067629.594 Coe S, Ryan L (2016) Impact of polyphenol-rich sources on acute postprandial glycaemia: a systematic review. J Nutr Sci 5:e24. https://doi.org/10.1017/jns.2016.11 Crane TE, Khulpateea BR, Alberts DS, Basen-Engquist C, Thomson CA (2013) Dietary intake and ovarian cancer risk: a systematic review. Cancer Epidemiol Biomark Prev 23:255–273. https:// doi.org/10.1158/1055-9965.EPI-13-0515 Crowe FL, Key TJ, Appleby PN, Overvad K, Schmidt EB, Egeberg R, Tjønneland A, Kaaks R, Teucher B, Boeing H, Weikert C, Trichopoulou A, Ouranos V, Valanou E, Masala G, Sieri S, Panico S, Tumino R, Matullo G, Mesquita HBBD, Boer JMA, Beulens JWJ, Schouw YTVD, Quirós JR, Buckland G, Sánchez MJ, Dorronsoro M, Huerta JM, Moreno-Iribas C, Hedblad B, Jansson JH, Wennberg P, Khaw KT, Wareham N, Ferrari P, Illner AK, Chuang SC, Norat T, Danesh J, Riboli E (2012) Dietary fibre intake and ischaemic heart disease mortality: the European Prospective Investigation into Cancer and Nutrition-Heart study. Eur J Clin Nutr 66:950–956. https://doi.org/10.1038/ejcn.2012.51 Dai Z, Butler LM, Dam RMV, Ang LW, Yuan JM, Koh WP (2014) Adherence to a vegetable-fruit-­ soy dietary pattern or the alternative healthy eating index is associated with lower hip fracture risk among Singapore Chinese. J Nutr 144:511–518. https://doi.org/10.3945/jn.113.187955

References

337

Dror Y, Giveon SM, Hoshen M, Feldhamer I, Balicer RD, Feldman BS (2013) Vitamin D levels for preventing acute coronary syndrome and mortality: evidence of a nonlinear association. J Clin Endocrinol Metab 98:2160–2167 Egeberg R, Olsen A, Loft S, Christensen J, Johnsen NF, Overvad K, Tjønneland A (2010) Intake of wholegrain products and risk of colorectal cancers in the Diet, Cancer and Health cohort study. Br J Cancer 103:730–734. https://doi.org/10.1038/sj.bjc.6605806 Encarnação JC, Abrantes AM, Pires AS, Botelho MF (2015) Revisit dietary fiber on colorectal cancer: butyrate and its role on prevention and treatment. Cancer Metastasis Rev 34:465–478 Esmaillzadeh A, Mirmiran P, Azizi F (2005) Whole-grain consumption and the metabolic syndrome: a favorable association in Tehranian adults. Eur J Clin Nutr 59:353–362. https://doi. org/10.1038/sj.ejcn.1602080 Fang L, Li W, Zhang W, Wang Y, Fu S (2015) Association between whole-grain intake and stroke risk: evidence from a meta-analysis. Int J Clin Exp Med 8:16978–16983 Farvid MS, Cho E, Eliassen AH, Chen WY, Willett WC (2016a) Lifetime grain consumption and breast cancer risk. Breast Cancer Res Treat 159:335–345. https://doi.org/10.1007/ s10549-016-3910-0 Farvid MS, Eliassen AH, Cho E, Liao X, Chen WY, Willett WC (2016b) Dietary fiber intake in young adults and breast cancer risk. Pediatrics 137:e20151226. https://doi.org/10.1542/ peds.2015-1226 Ferguson LR (2005) Does a diet rich in dietary fibre really reduce the risk of colon cancer? Dig Liver Dis 37:139–141. https://doi.org/10.1016/j.dld.2004.10.010 Ferguson LR, Harris PJ (2003) The dietary fibre debate: more food for thought. Lancet 361:1487– 1488. https://doi.org/10.1016/S0140-6736(03)13219-9 Ferguson LR, Harris PJ (2005) Dietary fibres and human health. Mol Nutr Food Res 49:517. https://doi.org/10.1002/mnfr.200590023 Flight I, Clifton P (2006) Cereal grains and legumes in the prevention of coronary heart disease and stroke: a review of the literature. Eur J Clin Nutr 60:1145–1159 Flint AJ, Hu FB, Glynn RJ, Jensen MK, Franz M, Sampson L, Rimm EB (2009) Whole-grains and incident hypertension in men. Am J Clin Nutr 90:493–498. https://doi.org/10.3945/ ajcn.2009.27460 Fraser GE (2011) A possible protective effect of nut consumption on risk of coronary heart disease. Arch Intern Med 152:1416. https://doi.org/10.1001/archinte.1992.00400190054010 Fuchs CS, Giovannucci EL, Colditz GA, Hunter DJ, Stampfer MJ, Rosner B, Speizer FE, Willett WC (1999) Dietary fiber and the risk of colorectal cancer and adenoma in women. NEJM 340:169–176 Fung TT, Hu FB, Pereira MA, Liu S, Stampfer MJ, Colditz GA, Willett WC (2002) Whole-grain intake and the risk of type 2 diabetes: a prospective study in men. Am J Clin Nutr 76:535–540 Gatta G, Ciccolallo L, Capocaccia R, Coleman MP, Hakulinen T, Møller H, Berrino F, Oberaigner W, Storm HH, Aareleid T, Lefevre H, Mace-Lesec’h J, Arveux P, Mathieu-Daude H, Raverdy N, Ziegler H, Tryggvadottir L, Crosignani P, Ferretti S, Conti E, Vercelli M, Quaglia A, Federico M, Man-gone L, Ponz De Leon M, Lisi VD, Serventi L, Zanetti R, Gafà L, Tumino R, Falcini F, Crocetti E, Paci E, Rachtan J, Bielska-Lasota M, Wronkowski Z, Obsitnikova A, Plesko I, Pompe-Kirn V, Martinez-Garcia C, Garau I, Navarro C, Ardanaz E, Moreno C, Borràs J, Galceran J, Möller T, Torhorst J, Lutz JM, Bouchardy C, Coebergh JWW, Damhuis RAM, Black R, Davies TW, Godward S, Williams EMI, Forman D, Roche M, Edwards S, Smith J, Møller H, Bell J, Lawrence G, Micheli A, Sant M, Verdecchia A, Coebergh JWW, Estéve J, Faivre J, Hakulinen T, Martinez-Garcia C (2003) Differences in colorectal cancer survival between European and US populations: the importance of sub-site and morphology. Eur J Cancer 39:2214–2222. https://doi.org/10.1016/S0959-8049(03)00549-5 Georgoulis M, Kontogianni MD, Margariti A, Tiniakos D, Fragopoulou E, Zafiropoulou R, Papatheodoridis G (2015) Associations between dietary intake and the presence of the metabolic syndrome in patients with non-alcoholic fatty liver disease. J Hum Nutr Diet 28:409–415. https://doi.org/10.1111/jhn.12323

338

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

Gianfredia V, Salvatorib T, Villarinib M, Morettib M, Nuccic D, Realdon S (2018) Is dietary fibre truly protective against colon cancer? A systematic review and meta-analysis. Int J Food Sci Nutr 69:904–915. https://doi.org/10.1080/09637486.2018.1446917 Goletzke J, Buyken AE, Joslowski G, Bolzenius K, Remer T, Carstensen M, Egert S, Nöthlings U, Rathmann W, Roden M, Herder C (2014) Increased intake of carbohydrates from sources with a higher glycemic index and lower consumption of whole-grains during puberty are prospectively associated with higher IL-6 concentrations in younger adulthood among healthy individuals. J Nutr 144:1586–1593. https://doi.org/10.3945/jn.114.193391 Gonzalez CA, Riboli E (2006) Diet and cancer prevention: where we are, where we are going. Nutr Cancer 56:225–231 Gonzalez-Anton C, Rico MC, Sanchez-Rodriguez E, Ruiz-Lopez MD, Gil A, Mesa MD (2015) Glycemic responses, appetite ratings and gastrointestinal hormone responses of most common breads consumed in Spain. A randomized control trial in healthy humans. Nutrients 7:4033– 4053. https://doi.org/10.3390/nu7064033 Hajishafiee M, Saneei P, Benisi-Kohansal S, Esmaillzadeh A (2016) Cereal fibre intake and risk of mortality from all causes, CVD, cancer and inflammatory diseases: a systematic review and meta-analysis of prospective cohort studies. Br J Nutr 116:343–352. https://doi.org/10.1017/ s0007114516001938 Hamer M, Chida Y (2007) Intake of fruit, vegetables, and antioxidants and risk of type 2 diabetes: systematic review and meta-analysis. J Hypertens 25:2361–2369. https://doi.org/10.1097/ HJH.0b013e3282efc214 Hansen L, Skeie G, Landberg R, Lund E, Palmqvist R, Johansson I, Dragsted LO, Egeberg R, Johnsen NF, Christensen J, Overvad K, Tjønneland A, Olsen A (2012) Intake of dietary fiber, especially from cereal foods, is associated with lower incidence of colon cancer in the HELGA cohort. Int J Cancer 131:469–478. https://doi.org/10.1002/ijc.26381 Haqq J, Howells LM, Garcea G, Metcalfe MS, Steward WP, Dennison AR (2014) Pancreatic stellate cells and pancreas cancer: current perspectives and future strategies. Eur J Cancer 50:2570–2582. https://doi.org/10.1016/j.ejca.2014.06.021 Helnæs A, Kyrø C, Andersen I, Lacoppidan S, Overvad K, Christensen J, Tjønneland A, Olsen A (2016) Intake of whole-grains is associated with lower risk of myocardial infarction: the Danish diet, cancer and health cohort. Am J Clin Nutr 103:999–1007. https://doi.org/10.3945/ ajcn.115.124271 Huang T, Xu M, Lee A, Cho S, Qi L (2015) Consumption of whole-grains and cereal fiber and total and cause-specific mortality: prospective analysis of 367,442 individuals. BMC Med 13:59. https://doi.org/10.1186/s12916-015-0294-7 Hung HC, Joshipura KJ, Jiang R, Hu FB, Hunter D, Smith-Warner SA, Colditz GA, Rosner B, Spiegelman D, Willett WC (2004) Fruit and vegetable intake and risk of major chronic disease. J Natl Cancer Inst 96:1577–1584. https://doi.org/10.1093/jnci/djh296 Hur Y, Reicks M (2012) Relationship between whole-grain intake, chronic disease risk indicators, and weight status among adolescents in the National Health and Nutrition Examination Survey, 1999-2004. J Acad Nutr Diet 112:46–55. https://doi.org/10.1016/j.jada.2011.08.028 Jacobs DR, Marquart L, Slavin J, Kushi LH (1998a) Whole-grain intake and cancer: an expanded review and meta-analysis. Nutr Cancer 30:85–96 Jacobs DR, Meyer KA, Kushi LH, Folsom AR (1998b) Whole-grain intake may reduce the risk of ischemic heart disease death in postmenopausal women: the Iowa Women’s Health Study. Am J Clin Nutr 68:248–257 Jacobs DR, Andersen LF, Blomhoff R (2007) Whole-grain consumption is associated with a reduced risk of noncardiovascular, noncancer death attributed to inflammatory diseases in the Iowa Women’s Health Study. Am J Clin Nutr 85:1606–1614 Jacobs DR, Meyer KA, Kushi LH, Folsom AR (1999) Is whole-grain intake associated with reduced total and cause-specific death rates in older women? The Iowa Women’s Health Study. Am J Public Health 89:322–329. https://doi.org/10.2105/AJPH.89.3.322

References

339

Jacobs DR, Meyer HE, Solvoll K (2001) Reduced mortality among whole-grain bread eaters in men and women in the Norwegian county study. Eur J Clin Nutr 55:137–143. https://doi. org/10.1038/sj.ejcn.1601133 Jacobs ET, Thompson PA, Martınez E (2007) Diet, gender, and colorectal neoplasia. J Clin Gastroenterol 41:731–746 Jacobs DR, Hohe C, Mursu J, Robien K, Folsom AR (2010) Whole-grain intake, incident hip fracture and presumed frailty in the Iowa Women’s Health Study. Br J Nutr 104:1537–1543. https:// doi.org/10.1017/S0007114510002382 Jensen MK, Koh-Banerjee P, Hu FB, Franz M, Sampson L, Grønbœk M, Rimm EB (2004) Intakes of whole-grains, bran, and germ and the risk of coronary heart disease in men. Am J Clin Nutr 80:1492–1499 Johnsen NF, Frederiksen K, Christensen J, Skeie G, Lund E, Landberg R, Johansson I, Nilsson LM, Halkjær J, Olsen A, Overvad K, Tjønneland A (2015) Whole-grain products and whole-­ grain types are associated with lower all-cause and cause-specific mortality in the Scandinavian HELGA cohort. Br J Nutr 114:608–623. https://doi.org/10.1017/s0007114515001701 Juan J, Liu G, Willett WC, Hu FB, Rexrode KM, Sun Q (2017) Whole-grain consumption and risk of ischemic stroke. Stroke 48:3203–3209. https://doi.org/10.1161/strokeaha.117.018979 Katcher HI, Legro RS, Kunselman AR, Gillies PJ, Demers LM, Bagshaw DM, Kris-Etherton PM (2008) The effects of a whole-grain-enriched hypocaloric diet on cardiovascular disease risk factors in men and women with metabolic syndrome. Am J Clin Nutr 87:79–90 Kelly FJ (2005) Vitamins and respiratory disease: antioxidant micronutrients in pulmonary health and disease. Proc Nutr Soc 64:510–526. https://doi.org/10.1079/pns2005457 Knudsen MD, Kyro C, Olsen A, Dragsted LO, Skeie G, Lund E, Åman P, Nilsson LM, Mesquita HBBD, Tjonneland A, Landberg R (2014) Self-reported whole-grain intake and plasma alkylresorcinol concentrations in combination in relation to the incidence of colorectal cancer. Am J Epidemiol 179:1188–1196. https://doi.org/10.1093/aje/kwu031 Koushik A, Hunter DJ, Spiegelman D, Beeson WL, Brandt PAVD, Buring JE, Calle EE, Cho E, Fraser GE, Freudenheim JL, Fuchs CS, Giovannucci EL, Goldbohm RA, Harnack L, Jacobs DR, Kato I, Krogh V, Larsson SC, Leitzmann MF, Marshall JR, McCullough ML, Miller AB, Pietinen P, Rohan TE, Schatzkin A, Sieri S, Virtanen MJ, Wolk A, Zeleniuch-Jacquotte A, Zhang SM, Smith-Warner SA (2007) Fruits, vegetables, and colon cancer risk in a pooled analysis of 14 cohort studies. J Natl Cancer Inst 99:1471–1483. https://doi.org/10.1093/jnci/ djm155 Kristensen SL, Preiss D, Jhund PS, Squire I, Cardoso JS, Merkely B, Martinez F, Starling RC, Desai AS, Lefkowitz MP, Rizkala AR, Rouleau JL, Shi VC, Solomon SD, Swedberg K, Zile MR, McMurray JJV, Packer M (2016) Risk related to pre-diabetes mellitus and diabetes mellitus in heart failure with reduced ejection fraction: insights from prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure trial. Circ Heart Fail 9:e002560. https://doi.org/10.1161/CIRCHEARTFAILURE.115.002560 Kuijsten A, Aune D, Schulze MB, Norat T, Woudenbergh GJV, Beulens JWJ, Sluijs I, Spijkerman AMW, vander A DL, Palli D, Kühn T, Wendt A, Buijsse B, Boeing H, Pala V, Amiano P, Buckland G, Huerta Castaño JM, Tjønneland A, Kyrø C, Redondo ML, Sacerdote C, Sánchez MJ, Fagherazzi G, Balkau B, Lajous M, Panico S, Franks PW, Rolandsson O, Nilsson P, Orho-­ Melander M, Overvad K, Huybrechts I, Slimani N, Tumino R, Barricarte A, Key TJ, EJM F, Langenberg C, Sharp S, Forouhi NG, Riboli E, Wareham NJ (2015) Dietary fibre and incidence of type 2 diabetes in eight European countries: the EPIC-InterAct study and a meta-analysis of prospective studies. Diabetologia 58:1394–1408. https://doi.org/10.1007/s00125-015-3585-9 Kunzmann AT, Coleman JG, Huang WY, Kitahara CM, Cantwell MM, Berndt SI (2015) Dietary fiber intake and risk of colorectal cancer and incident and recurrent adenoma in the prostate, lung, colorectal, and ovarian cancer screening trial. Am J Clin Nutr 102:881–890. https://doi. org/10.3945/ajcn.115.113282

340

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

Kyrø C, Skeie G, Loft S, Landberg R, Christensen J, Lund E, Nilsson LM, Palmqvist R, Tjønneland A, Olsen A (2013) Intake of whole-grains from different cereal and food sources and incidence of colorectal cancer in the Scandinavian HELGA cohort. Cancer Causes Control 24:1363– 1374. https://doi.org/10.1007/s10552-013-0215-z Kyrø C, Tjønneland A, Overvad K, Olsen A, Landberg R (2018) Higher whole-grain intake is associated with lower risk of type 2 diabetes among middle-aged men and women: the Danish diet, cancer, and health cohort. J Nutr 148:1434–1444. https://doi.org/10.1093/jn/nxy112 Laar FAVD, Akkermans RP, Binsbergen JJV (2007) Limited evidence for effects of diet for type 2 diabetes from systematic reviews. Eur J Clin Nutr 61:929–937. https://doi.org/10.1038/ sj.ejcn.1602611 Laddomada B, Caretto S, Mita G (2015) Wheat bran phenolic acids: bioavailability and stability in whole-wheat-based foods. Molecules 20:15666–15685. https://doi.org/10.3390/ molecules200915666 Lang R, Jebb SA (2003) Who consumes whole-grains, and how much? Proc Nutr Soc 62:123–127. https://doi.org/10.1079/PNS2002219 Larsson SC, Wolk A (2014) Dietary fiber intake is inversely associated with stroke incidence in healthy Swedish adults. J Nutr 144:1952–1955. https://doi.org/10.3945/jn.114.200634 Larsson SC, Giovannucci E, Bergkvist L, Wolk A (2005) Whole-grain consumption and risk of colorectal cancer: a population-based cohort of 60 000 women. Br J Cancer 92:1803–1807. https://doi.org/10.1038/sj.bjc.6602543 Lazarou C, Panagiotakos D, Matalas AL (2012) The role of diet in prevention and management of type 2 diabetes: implications for public health. Crit Rev Food Sci Nutr 52:382–389. https://doi. org/10.1080/10408398.2010.500258 Lefevre M, Jonnalagadda S (2012) Effect of whole-grains on markers of subclinical inflammation. Nutr Rev 70:387–396. https://doi.org/10.1111/j.1753-4887.2012.00487.x Lei Q, Zheng H, Bi J, Wang X, Jiang T, Gao X, Tian F, Xu M, Wu C, Zhang L, Li N, Li J (2016) Whole-grain intake reduces pancreatic cancer risk. Medicine 95:e2747. https://doi. org/10.1097/MD.0000000000002747 Leo AD, Curigliano G, Diéras V, Malorni L, Sotiriou C, Swanton C, Thompson A, Tutt A, Piccart M (2015) New approaches for improving outcomes in breast cancer in Europe. Breast 24:321– 330. https://doi.org/10.1016/j.breast.2015.03.001 Li S, Flint A, Pai JK, Forman JP, Hu FB, Willett WC, Rexrode KM, Mukamal KJ, Rimm EB (2014) Dietary fiber intake and mortality among survivors of myocardial infarction: prospective cohort study. BMJ 348:g2659. https://doi.org/10.1136/bmj.g2659 Liao CY, Lee CC, Tsai C, Hsueh CW, Wang CC, Chen IH, Tsai MK, Liu MY, Hsieh AT, Su KJ, Wu HM, Huang SC, Wang YC, Wang CY, Huang SF, Yeh YC, Ben RJ, Chien ST, Hsu CW, Kuo WH (2015) Novel investigations of flavonoids as chemopreventive agents for hepatocellular carcinoma. Biomed Res Int 2015:840542. https://doi.org/10.1155/2015/840542 Lillioja S, Neal AL, Tapsell L, Jacobs DR (2013) Whole-grains, type 2 diabetes, coronary heart disease, and hypertension: links to the aleurone preferred over indigestible fiber. Biofactors 39:242–258. https://doi.org/10.1002/biof.1077 Liu S, Stampfer MJ, Hu FB, Giovannucci E, Rimm E, Manson JAE, Hennekens CH, Willett WC (1999) Whole-grain consumption and risk of coronary heart disease: results from the Nurses’ Health Study. Am J Clin Nutr 70:412–419. https://doi.org/10.1093/ajcn/70.3.412 Liu S, Manson JAE, Stampfer MJ, Hu FB, Giovannucci E, Coldic GA, Hennekens CH, Willett WC (2000) A prospective study of whole-grain intake and risk of type 2 diabetes mellitus in US women. Am J Public Heallh 90:1409–1415 Liu S, Manson JE, Stampfer MJ, Rexrode KM, Hu FB, Rimm EB, Willett WC (2003) Whole-grain consumption and risk of ischemic stroke in women. JAMA 284:1534. https://doi.org/10.1001/ jama.284.12.1534 Lopez AD, Mathers CD, Ezzati M, Jamison DT, CJL M (2006) Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. Lancet 367:1747–1757

References

341

Lutsey PL, Jacobs DR, Kori S, Mayer-Davis E, Shea S, Steffen LM, Szklo M, Tracy R (2007) Whole-grain intake and its cross-sectional association with obesity, insulin resistance, inflammation, diabetes and subclinical CVD: the MESA study. Br J Nutr 98:397–405. https://doi. org/10.1017/S0007114507700715 Ma X, Tang W-G, Yang Y, Zhang QL, Zheng JL, Xiang YB (2016) Association between whole-­ grain intake and all-cause mortality: a meta-analysis of cohort studies. Oncotarget 7:61996– 62005. https://doi.org/10.18632/oncotarget.11491 Ma Y, Hu M, Zhou L, Ling S, Li Y, Kong B, Huang P (2018) Dietary fiber intake and risks of proximal and distal colon cancers. Medicine 97:36. https://doi.org/10.1097/MD.0000000000011678 Marventano S, Vetrani C, Vitale M, Godos J, Riccardi G, Grosso G (2017) Whole-grain intake and glycaemic control in healthy subjects: a systematic review and meta-analysis of randomized controlled trials. Nutrients 7:769. https://doi.org/10.3390/nu9070769 McEligot AJ, Largent J, Ziogas A, Peel D, Anton-Culver H (2006) Dietary fat, fiber, vegetable, and micronutrients are associated with overall survival in postmenopausal women diagnosed with breast cancer. Nutr Cancer 55:132–140. https://doi.org/10.1207/s15327914nc5502_3 McKeown NM, Meigs JB, Liu S, Wilson PWF, Jacques PF (2002) Whole-grain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular disease in the Framingham Offspring Study. Am J Clin Nutr 76:390–398 Mellen PB, Walsh TF, Herrington DM (2008) Whole-grain intake and cardiovascular disease: a meta-analysis. Nutr Metab Cardiovasc Dis 18:283–290. https://doi.org/10.1016/j. numecd.2006.12.008 Meyer KA, Kushi LH, Jacobs DR, Slavin J, Sellers TA, Folsom AR (2000) Carbohydrates, dietary fiber, and incident type 2 diabetes in older women. Am J Clin Nutr 71:921–930 Michels KB, Giovannucci E, Joshipura KJ, Rosner BA, Stampfer MJ, Fuchs CS, Colditz GA, Speizer FE, Willett WC (2000) Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst 92:1740–1752 Montonen J, Knekt P, Järvinen R, Aromaa A, Reunanen A (2003) Whole-grain and fiber intake and the incidence of type 2 diabetes. Am J Clin Nutr 77:622–629 Montonen J, Boeing H, Fritsche A, Schleicher E, Joost HG, Schulze MB, Steffen A, Pischon T (2013) Consumption of red meat and whole-grain bread in relation t biomarkers of obesity, inflammation, glucose metabolism and oxidative stress. Eur J Nutr 52:337–345. https://doi. org/10.1007/s00394-012-0340-6 Mourouti N, Kontogianni MD, Papavagelis C, Psaltopoulou T, Kapetanstrataki MG, Plytzanopoulou P, Vassilakou T, Malamos N, Linos A, Panagiotakos DB (2016) Whole-grain consumption and breast cancer: a case-control study in women. J Am Coll Nutr 35:143–149. https://doi.org/10. 1080/07315724.2014.963899 Mozaffarian D, Kumanyika SK, Lemaitre RN, Olson JL, Burke GL, Siscovick DS (2014) Cereal, fruit, and vegetable fiber intake and the risk of cardiovascular disease in elderly individuals. JAMA 289:1659–1666 Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, Das SR, Ferranti SD, Després JP, Fullerton HJ, Howard VJ, Huffman MD, Isasi CR, Jiménez MC, Judd SE, Kissela BM, Lichtman JH, Lisabeth LD, Liu S, Mackey RH, Magid DJ, McGuire DK, Mohler ER, Moy CS, Muntner P, Mussolino ME, Nasir K, Neumar RW, Nichol G, Palaniappan L, Pandey DK, Reeves MJ, Rodriguez CJ, Rosamond W, Sorlie PD, Stein J, Towfighi A, Turan TN, Virani SS, Woo D, Yeh RW, Turner MB (2015) Heart disease and stroke statistics—2016 update. Circulation 133:e38–e360. https://doi.org/10.1161/CIR.0000000000000350 Munter JSLD, Hu FB, Spiegelman D, Franz M, Dam RMV (2007) Whole-grain, bran, and germ intake and risk of type 2 diabetes: a prospective cohort study and systematic review. PLoS Med 4:e261. https://doi.org/10.1371/journal.pmed.0040261 Murphy N, Norat T, Ferrari P, Jenab M, Mesquita BBD, Skeie G, Dahm CC, Overvad K, Olsen A, Tjønneland A, Clavel-Chapelon F, Boutron-Ruault MC, Racine A, Kaaks R, Teucher B, Boeing H, Bergmann MM, Trichopoulou A, Trichopoulos D, Lagiou P, Palli D, Pala V, Panico S, Tumino R, Vineis P, Siersema P, Duijnhoven FV, Peeters PHM, Hjartaker A, Engeset D,

342

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

González CA, Sánchez MJ, Dorronsoro M, Navarro C, Ardanaz E, Quirós JR, Sonestedt E, Ericson U, Nilsson L, Palmqvist R, Khaw KT, Wareham N, Key TJ, Crowe FL, Fedirko V, Wark PA, Chuang SC, Riboli E (2012) Dietary fibre intake and risks of cancers of the colon and rectum in the European prospective investigation into cancer and nutrition (EPIC). PLoS One 7:e39361. https://doi.org/10.1371/journal.pone.0039361 Murtaugh MA, Jacobs DR, Jacob B, Steffen LM, Marquart L (2003) Epidemiological support for the protection of whole-grains against diabetes. Proc Nutr Soc 62:143–149. https://doi. org/10.1079/pns2002223 Nagengast FM, Grubben JAL, Munster V (1995) Role of bile acids in colorectal carcinogenesis. Eur J Cancer 31A:1067–1070 Nakaji S, Shimoyama T, Wada S, Sugawara K, Tokunaga S, MacAuley D, Baxter D (2003) No preventive effect of dietary fiber against colon cancer in the Japanese population: a cross-sectional analysis. Nutr Cancer 45:156–159 Negri E, Franceschi S, Parpinel M, Vecchia CL (1998) Fiber intake and risk of colorectal cancer. Cancer Epidemiol Biomark Prev 7:667–671 Negri E, Tavani A, Vecchia CL, Levi F, Franceschi S, Jacobs DR, Chatenoud L (2002) Whole-grain food intake and cancer risk. Int J Cancer 77:24–28. https://doi.org/10.1002/ (sici)1097-0215(19980703)77:13.3.co;2-0 Nistal E, Fernández-Fernández N, Vivas S, Olcoz JL (2015) Factors determining colorectal cancer: the role of the intestinal microbiota. Front Oncol 5:220. https://doi.org/10.3389/ fonc.2015.00220 Nomura AMY, Hankin JH, Henderson BE, Wilkens LR, Murphy SP, Pike MC, Le Marchand L, Stram DO, Monroe KR, Kolonel LN (2007) Dietary fiber and colorectal cancer risk: the multiethnic cohort study. Cancer Causes Control 18:753–764. https://doi.org/10.1007/ s10552-007-9018-4 Otani T, Iwasaki M, Ishihara J, Sasazuki S, Inoue M, Tsugane S (2006) Dietary fiber intake and subsequent risk of colorectal cancer: the Japan Public Health Center-Based Prospective Study. Int J Cancer 119:1475–1480. https://doi.org/10.1002/ijc.22007 Park Y, Hunter DJ, Spiegelman D, Bergkvist L, Berrino F, Brandt PAVD, Buring JE, Colditz GA, Freudenheim JL, Fuchs CS, Giovannucci E, Goldbohm RA, Graham S, Harnack L, Hartman AM, Jacobs DR, Kato I, Krogh V, Leitzmann MF, McCullough ML, Miller AB, Pietinen P, Rohan TE, Schatzkin A, Willett WC, Wolk A, Zeleniuch-Jacquotte A, Zhang SM, Smith-Warner SA (2005) Dietary fiber intake and risk of colorectal cancer: a pooled analysis of prospective cohort studies. J Am Med Assoc 294:2849–2857. https://doi.org/10.1001/jama.294.22.2849 Parker ED, Liu S, Horn LV, Tinker LF, Shikany JM, Eaton CB, Margolis KL (2013) The association of whole-grain consumption with incident type 2 diabetes: the Women’s Health Initiative Observational Study. Ann Epidemiol 23:321–327. https://doi.org/10.1016/j. annepidem.2013.03.010 Pimenta AM, Toledo E, Rodriguez-Diez MC, Gea A, Lopez-Iracheta R, Shivappa N, Hébert JR, Martinez-Gonzalez MA (2015) Dietary indexes, food patterns and incidence of metabolic syndrome in a Mediterranean cohort: the SUN project. Clin Nutr 34:508–514. https://doi. org/10.1016/j.clnu.2014.06.002 Priebe M, Binsbergen JV, Vos RD, Vonk RJ (2008) Whole-grain foods for the prevention of type 2 diabetes mellitus (Review). Cochrane Database Syst Rev (1):CD006061. https://doi. org/10.1002/14651858.CD006061.pub2. www.cochranelibrary.com Rave K, Roggen K, Dellweg S, Heise T, Dieck HT (2007) Improvement of insulin resistance after diet with a whole-grain based dietary product: results of a randomized, controlled cross-over study in obese subjects with elevated fasting blood glucose. Br J Nutr 98:929–936. https://doi. org/10.1017/S0007114507749267 Rebello SA, Koh H, Chen C, Naidoo N, Odegaard AO, Koh WP, Butler LM, Yuan JM, Dam RM (2014) Amount, type, and sources of carbohydrates in relation to ischemic heart disease mortality in a Chinese population: a prospective cohort study. Am J Clin Nutr 100:53–64. https://doi. org/10.3945/ajcn.113.076273

References

343

Reicks M, Jonnalagadda S, Albertsonb AM, Joshi N (2014) Total dietary fiber intakes in the US population are related to whole-grain consumption: results from the National Health and Nutrition Examination Survey 2009 to 2010. Nutr Res 34:226–234. https://doi.org/10.1016/j. nutres.2014.01.002 Riboli E, Norat T (2003) Epidemiologic evidence of the protective effect of fruit and. Am J Clin Nutr 78:559S–569S Richardson DP (2003) Wholegrain health claims in Europe. Proc Nutr Soc 62:161–169. https:// doi.org/10.1079/PNS2002226 Ries LAG, Melbert D, Krapcho M, Mariotto A, Miller BA, Feuer EJ, Clegg L, Horner MJ, Howlader N, Eisner MP, Reichman M, Edwards BK (eds) (2007) SEER Cancer Statistics Review, 1975-­ 2004. National Cancer Institute, Bethesda, http://seer.cancer.gov/csr/1975_2004/, based on November 2006 SEER data submission, posted to the SEER web site Rodrigues TC, Canani LH, Gross JL (2010) Metabolic syndrome, insulin resistance and cardiovascular disease in type-1 diabetes mellitus. Arq Bras Cardiol 94:125–130 Roncucci L, Mariani F (2015) Prevention of colorectal cancer: how many tools do we have in our basket? Eur J Int Med 26:752–756. https://doi.org/10.1016/j.ejim.2015.08.019 Rose DP, Goldman M, Connolly JM, Strong LE (1991) High-fiber diet reduces serum estrogen concentrations in premenopausal women. Am J Clin Nutr 54:520–525. https://doi.org/10.1093/ ajcn/54.3.520 Ross AB (2015) Whole-grains beyond fibre: what can metabolomics tell us about mechanisms? Proc Nutr Soc 74:320–327. https://doi.org/10.1017/S0029665114001542 Rozen P, Rosner G, Liphshitz I, Barchana M (2007) The changing incidence and sites of colorectal cancer in the Israeli Arab population and their clinical implications. Int J Cancer 120:147–151. https://doi.org/10.1002/ijc.22141 Sahyoun NR, Jacques PF, Zhang XL, Juan W, McKeown NM (2006) Whole-grain intake is inversely associated with the metabolic syndrome and mortality in older adults. Am J Clin Nutr 83:124–131 Schatzkin A, Mouw T, Park Y, Subar AF, Kipnis V, Hollenbeck A, Leitzmann MF, Thompson FE (2007) Dietary fiber and whole-grain consumption in relation to colorectal cancer in the NIH-­ AARP Diet and Health Study. Am J Clin Nutr 85:1353–1360 Schatzkin A, Park Y, Leitzmann MF, Hollenbeck AR, Cross AJ (2008) Prospective study of dietary fiber, whole-grain foods, and small intestinal cancer. Gastroenterology 135:1163–1167. https:// doi.org/10.1053/j.gastro.2008.07.015 Singh PN, Fraser GE (1998) Dietary risk factors for colon cancer in a low-risk population. Am J Epidemiol 148:761–774 Slavin JL (2000) Mechanisms for the impact of whole-grain foods on cancer risk. J Am Coll Nutr 19:300S–307S Sonnenberg A, Byrd-Clark DD (2014) US hospitalizations for colorectal cancer 1970–2010. Dig Dis Sci 59:282–286. https://doi.org/10.1007/s10620-013-2921-5 Steffen LM, Jacobs DR, Stevens J, Shahar E, Carithers T, Folsom AR (2003) Associations of whole-grain, refined-grain, and fruit and vegetable consumption with risks of all-cause mortality and incident coronary artery disease and ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) Study. Am J Clin Nutr 78:383–390 Sun G, Zhang S, Xie Y, Zhang Z, Zhao W (2016) Gallic acid as a selective anticancer agent that induces apoptosis in SMMC-7721 human hepatocellular carcinoma cells. Oncol Lett 11:150– 158. https://doi.org/10.3892/ol.2015.3845 Sun T, Zhang Y, Huang H, Wang X, Zhou L, Li S, Huang S, Xie C, Wen Y, Zhu Y, Hu X, Chen L, Li P, Chen S, Yang W, Bao W, Hu FB, Cheng J, Liu L (2019) Plasma alkylresorcinol metabolite, a biomarker of whole-grain wheat and rye intake, and risk of ischemic stroke: a case-control study. Am J Clin Nutr 109:1–7. https://academic.oup.com/ajcn/article-abstract/109/2/1/5308616 Tan KY (2015) Fiber and colorectal diseases: separating fact from fiction. World J Gastroenterol 13:4161. https://doi.org/10.3748/wjg.v13.i31.4161

344

15  The Health Impact of the Whole-Wheat Intake as Evaluated by Wide-Scaled…

Terry P, Giovannucci E, Michels KB, Bergkvist L, Hansen H, Holmberg L, Wolk A (2001) Fruit, vegetables, dietary fiber, and risk of colorectal cancer. J Natl Cancer Inst 93:525–533. https:// doi.org/10.1093/jnci/93.7.525 Thorogood M, Simera I, Dowler E, Summerbell C, Brunner E (2007) A systematic review of population and community dietary interventions to prevent cancer. Nutr Res Rev 20:74–88. https:// doi.org/10.1017/S0954422407733073 Vainio H, Weiderpass E (2006) Fruit and vegetables in cancer prevention severe human pathogens. Nutr Cancer 54:111–142. https://doi.org/10.1207/s15327914nc5401_13 Vitaglione P, Mennella I, Ferracane R, Rivellese AA, Giacco R, Ercolini D, Gibbons SM, Storia AL, Gilbert JA, Jonnalagadda S, Thielecke F, Gallo MA, Scalfi L, Fogliano V (2015) Whole-­ grain wheat consumption reduces inflammation in a randomized controlled trial on overweight and obese subjects with unhealthy dietary and lifestyle behaviors: role of polyphenols bound to cereal dietary fiber. Am J Clin Nutr 101:251–261. https://doi.org/10.3945/ajcn.114.088120 Vulcan A, Brändstedt J, Manjer J, Jirström K, Ohlsson B, Ericson U (2015) Fibre intake and incident colorectal cancer depending on fibre source, sex, tumour location and tumour, node, metastasis stage. Br J Nutr 114:959–969. https://doi.org/10.1017/s0007114515002743 Wang L, Gaziano JM, Liu S, Manson JAE, Buring JE, Sesso HD (2007) Whole- and refined-grain intakes and the risk of hypertension in women. Am J Clin Nutr 86:472–479 Wang CH, Qiao C, Wang RC, Zhou WP (2015) Dietary fiber intake and pancreatic cancer risk: a meta-analysis of epidemiologic studies. Sci Rep 5:10834. https://doi.org/10.1038/srep10834 Wei H, Gao Z, Liang R, Li Z, Hao H, Liu X (2016) Whole-grain consumption and the risk of all-cause, CVD and cancer mortality: a meta-analysis of prospective cohort studies. Br J Nutr 116:514–525. https://doi.org/10.1017/s0007114516001975 Wikipedia. https://www.wikipedia.org/ Willett WC, Stampper MJ, Colditz GA, Rosner BA, Speizer FE (1990) Relation of meat, fat, and fiber intake to the risk of colon, cancer in a prospective study among women. NEJM 323:1664–1672 World Cancer Research Fund. Global cancer data by country. http://www.wcrf.org/int/ cancer-facts-figures/data-cancer-frequency-country Wu H, Flint AJ, Qi Q, Dam RMV, Sampson LA, Rimm EB, Holmes MD, Willett WC, Hu FB, Sun Q (2015) Association between dietary whole-grain intake and risk of mortality: two large prospective studies in US men and women. JAMA Intern Med 175:373–384. https://doi. org/10.1001/jamainternmed.2014.6283 Xiao Y, Ke Y, Wu S, Huang S, Li S, Lv Z, Yeoh EK, Lao X, Wong S, Kim JH, Colditz GA, Tamimi RM, Su X (2018) Association between whole grain intake and breast cancer risk: a systematic review and meta-analysis of observational studies. Nutr J 17:87. https://doi.org/10.1186/ s12937-018-0394-2 Xu Y, Yang J, Du L, Li K, Zhou Y (2019) Association of whole grain, refined grain, and cereal consumption with gastric cancer risk: a meta-analysis of observational studies. Food Sci Nutr 7:256–265. https://doi.org/10.1002/fsn3.878 Yang W, Ma Y, Liu Y, Smith-Warner SA, Simon TG, Chong DQ, Qi Q, Meyerhardt JA, Giovannucci EL, Chan AT, Zhang X (2019) Association of intake of whole-grains and dietary fiber with risk of hepatocellular carcinoma in US adults. JAMA Oncol 5:879–886. https://doi.org/10.1001/ jamaoncol.2018.7159 Yao B, Fang H, Xu W, Yan Y, Xu H, Liu Y, Mo M, Zhang H, Zhao Y (2014) Dietary fiber intake and risk of type 2 diabetes: a dose-response analysis of prospective studies. Eur J Epidemiol 29:79–88. https://doi.org/10.1007/s10654-013-9876-x Ye EQ, Chacko SA, Chou EL, Kugizaki M, Liu S (2012) Greater whole-grain intake is associated with lower risk of type 2 diabetes, cardiovascular disease, and weight gain. J Nutr 142:1304– 1313. https://doi.org/10.3945/jn.111.155325 Zhang X, Shu L, Si C, Yu X, Gao W, Liao D, Zhang L, Liu X, Zheng P (2015) Dietary patterns and risk of stroke in adults:A systematic review and meta-analysis of prospective cohort studies. J Stroke Cerebrovasc Dis 24:2173–2182. https://doi.org/10.1016/j.jstrokecerebrovasdis.2015.05.0

References

345

Zhang Z, Wang D, Qiao S, Wu X, Cao S, Wang L, Su X, Li L (2017) Metabolic and microbial signatures in rat hepatocellular carcinoma treated with caffeic acid and chlorogenic acid. Sci Rep 7:4508. https://doi.org/10.1038/s41598-017-04888-y Zhang B, Zhao Q, Guo W, Bao W, Wang X (2018) Association of whole-grain intake with all-­ cause, cardiovascular, and cancer mortality: a systematic review and dose-response meta-­ analysis from prospective cohort studies. Eur J Clin Nutr 72:57–65. https://doi.org/10.1038/ ejcn.2017.149 Zheng B, Shen H, Han H, Han T, Qin Y (2018) Dietary fiber intake and reduced risk of ovarian cancer: a meta-analysis. Nutr J 17:99. https://doi.org/10.1186/s12937-018-0407-1 Zheng J, He J, Liao S, Cheng Z, Lin J, Huang K, Li X, Zheng K, Chen X, Lin L, Xia F, Liu J, Xu M, Chen T, Huang X, Cao X, Yang Z (2019) Preventive effects of combinative natural foods produced by elite crop varieties rich in anticancer effects on N-nitrosodiethylamine-induced hepatocellular carcinoma in rats. Food Sci Nutr 7:339–355. https://doi.org/10.1002/fsn3.896 Zhong X, Fang YJ, Pan ZZ, Lu MS, Zheng MC, Chen YM, Zhang CX (2014) Dietary fiber and fiber fraction intakes and colorectal cancer risk in Chinese adults. Nutr Cancer 66:351–361. https://doi.org/10.1080/01635581.2013.877496 Zhu Y, Conklin DR, Chen H, Wang L, Sang S (2011) 5-Alk(en)ylresorcinols as the major active components in wheat bran inhibit human colon cancer cell growth. Bioorg Med Chem 19:3973–3982. https://doi.org/10.1016/j.bmc.2011.05.025 Zong G, Gao A, Hu FB, Sun Q (2016) Whole-grain intake and mortality from all causes, cardiovascular disease, and cancer. Circulation 133:2370–2380. https://doi.org/10.1161/ CIRCULATIONAHA.115.021101

Chapter 16

Observational Studies on Law Scale Experimentations

The effect of the whole-wheat bread consumption on the decrease in the relative risk values of the non-communicable diseases (NCD) and mortality has clearly shown in a long list of epidemiological studied (Tables 15.1 and 15.2). Besides, we present here, with the presentation of the observational studies, the alleviative effect of the whole-bread on other health parameters: (a) adiposity; (b) carotid intima-media thickness (IMT); (c) angiography indications; Bread intake has claimed to increase adiposity which measured by BMI, waist circumference, body fat content, and some other anthropometric measurements. The public opinion considers that bread fattens (Serra-Majem and BautistaCastaño 2015; Williams 2018). Since the bread comprises the main energetic intake, the high bread intake well correlated with a higher BMI.  However, bread replacements are better inducers for the weight gain while whole-bread showed to lower the weight gain.

The Effect of the Whole-Wheat on the Adiposity Incidence Some studies have shown to moderate adiposity with the intake of the whole-­ wheat bread. In a study with 50 K subjects conducted in Norway, the authors used the central obesity measure (waist/hip) as the criterion for the health status as it more closely related to the metabolic and the health parameters rather than the BMI, as reported for cardiovascular disease, stroke, diabetes type 2, and all-cause mortality, espe© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_16

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cially among the older adults. The authors supposed that central obesity is a­ ssociated with unhealthy food-group choices and, in particular, energy-dense foods and beverages. Even there was limited evidence to support the superior discriminatory capability of any of the measures (BMI or waist/hip) (Huxley et  al. 2010) their conclusion support the notion that bread is not a fattening food item. People with higher central obesity reported a lower intake of bread in total and of the wholegrain bread in particular (Mostad et al. 2014). The effect of the whole-grain intake on the adiposity evaluated with 2.8 K subjects, aged 32–83  y, male and females, in the Framingham Heart Study. Whole-­ grain intake associated with the 12% decrease in the subcutaneous adipose tissue in the highest quintile level of the whole-grain intake compared with the lowest with 2895 ml subcutaneous adipose tissue and with a decrease of 17% in visceral adipose tissue, respectively. Refined grain intake showed an opposite trend for the highest quintile. Although both the subcutaneous adipose tissue and the visceral adipose tissue fat depots are metabolically active, the visceral adipose tissue compartment may be a unique pathogenic fat depot. The greater visceral adipose tissue may be responsible for the many aspects of the metabolic syndrome, including glucose intolerance, hypertension, dyslipidemia, and insulin resistance. Daily consumption of a whole-grain wheat breakfast cereal exerted a pronounced prebiotic effect on the human gut microbiota composition in healthy adults. In the US diet, wheat is the predominant contributor of the oligofructose which is an indigestible soluble fiber polymer with the prebiotic properties. The dietary fiber affects hunger and satiety by delaying gastric emptying, whereas other attributes of the whole-grain, such as dietary magnesium or particle size of the whole-grain foods, may enhance the insulin sensitivity and thereby prevent body fat accumulation. The authors conclude that adults who consume >3 servings whole-grains/d have significantly lower subcutaneous adipose tissue and visceral adipose tissue compared with those who rarely consume whole-grain foods, but this beneficial association may negate by the higher refined-grain intake (McKeown et al. 2010). In a study with 72 overweight and obese women in Copenhagen, subjects consuming whole-grain foods, as part of an energy-restricted diet experience a greater reduction in body weight and fat than participants consuming refinedgrains. The fat mass decreased more in the group of the participants consuming the whole-grain foods compared to those consuming the refined foods (23.0 vs 22.1%), while the difference in weight loss between groups was not significant. In 72 participants completed the study, which is the sample size required to observe a difference in the weight loss, the refined-grain consumption increased serum total and LDL cholesterol concentrations much higher than the wholegrain (Kristensen et al. 2012). The alleviative effect of the decrease in adiposity by the increase in the intake of the whole-grain clearly shown in the National Health and Nutrition Examination Survey conducted in the US with adults, 19–50 y. In subjects consumed 26 g/d grain fiber (the higher quintile) versus 13 g/d (the lower quintile) a lower prevalence of overweight/obesity observed (67 versus 72%), and a lower average BMI and waist

The Effect of the Whole-Wheat Intake on the Carotid Intima-Media Thickness (IMT)

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circumference (O’Neil et al. 2010). In 4 prospective studies comprised of 210 K subjects conducted in the US and Europe within 10 y follow-up, higher whole-grain intake showed a lower body weight. Interventional studies showed a lower effect of the whole-grain (McKeown et al. 2012). Whole-grain intake of 0.2 vs 2.9 serving/d or cereal fiber of 2.4 vs 9.3 g/d was inversely associated with BMI 26.8 vs 25.8, body fat 34.5 vs. 32.1% and trunk fat mass 43.0 vs 39.4% in the lowest compared with the highest quartile level of the whole-grain intake. Refined grain intake, total fiber, vegetable or fruit fiber, were not associated with any measure of the body fat distribution (McKeown et al. 2009). Higher fiber intake is likely to be less energy dense and lower in fat and added sugar. Many of the chronic diseases such as obesity, cardiovascular disease, and diabetes type 2 can be prevented or controlled by increasing the amounts and varieties of fiber-containing foods. The clinical studies have shown changes in the gastric emptying, gut hormones, glycemic index, and satiation indices with the increase in fiber supplements. Typically, large amounts of dietary fiber needed to alter the energy balance. Increasing consumption of dietary fiber with fruits, vegetables, whole-grain, and legumes across the life cycle is a critical step in stemming the obesity epidemic (Slavin 2005). A Spain study with >2.2 K subjects aged 55–80 y supported the suggestion that reducing white bread, but not whole-grain bread consumption, within a Mediterranean-style food pattern setting, associated with lower gains in the weight and the abdominal fat (Bautista-Castaño et al. 2013). In a comprehensive review, the authors concluded that even the high variability in the bread types, the whole-wheat bread showed increased satiety and fullness, and reduced hunger and prospective consumption compared with the white wheat bread (Gonzalez-Anton et al. 2017). A comprehensive review of 38 epidemiological studies shows that in the majority of the studies, the bread was not associated with an increase in the ponderable status, and that the whole-bread consumption is more beneficial than the refined bread, especially in a relation to the abdominal fat. The whole-grain bread does not influence weight gain and may be beneficial to the ponderable status. The majority of the studies suggest beneficial effects, of the refined bread but, with a possible relationship with excess abdominal fat (Williams 2018). These 10 studies show that the claim of the bread fattening does not support robust data. In most of the countries where the epidemiological studies with the bread intake were conducted, the annual wheat intake was 8  y in 4 US community in subjects aged >65  y, dietary fiber intake of 10 g/d decreased the IMT progression by 6.4 μm/y. Calculation of the dietary fiber types (pectin, fermentable dietary fiber or non-fermentable dietary) showed the same trend for all types of dietary fiber (Mozaffarian et al. 2014). In a study comprised of 600 subjects, aged 23–65  y, with an average dietary fiber of 19  g/d, carotid IMT scores were strongly associated with the total dietary fiber intake. At this amount of total dietary fiber, 19 g/d, the wheat fiber comprises a considerable share of the total dietary fiber intake. This study supports the notion of the positive effect of wheat-­fiber on the prevention of the increase of IMT by whole-wheat (Masley et al. 2015).

 he Effect of the Whole-Wheat Intake on the Angiography T Indications In a study conducted in 6 US hospitals in 229 women, aged 65 y, who underwent angiography tested for the effect of the whole-grain intake. Patients with higher intakes of cereal fiber (>3 g/Mcal) or >6 servings of whole-grains/wk. compared to the lower intakes were associated with a smaller decline in the minimum coronary artery diameter. Progression in percent stenosis tended to be less in the women with a higher intake of cereal fiber or whole-grain foods. This finding clearly shows the distinction between the alleviative effect of the whole-grain fiber and the fiber from other sources such as vegetable and fruits (Erkkilä et al. 2005).

 Continuous Model Showed by a Meta-Analysis A for the Effect of Whole-Grain Intake on the Relative Risk of Main Burdens According to the continuous model of the effect of the whole-grain intake on the 4 major burdens, we estimated the relative risk of the incidence of these burdens according to a non-linear model, at an intake of 170 g/d that comprises ~30% of the total energy intake. The meta-analysis comprises 135 M person-years of data from 185 prospective studies and 58 clinical trials. The following relative risk values estimated with the person-years for each estimation: (a) all-cause mortality with a relative risk of 0.81 and with 8.2 M person-years; (b) coronary hurt disease with a relative risk of 0.78 and with 2.4 M person-years; (c) diabetes with a relative risk of 0.58 and with 3.5 M person-years; (d) colorectal cancer with a relative risk of 0.84 and with 5.74 M person-years (Reynolds et al. 2019).

References

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The clear presentation of the continuous model for the effect of the whole-grain on the reduction of the main health burdens shows us that the increase of the whole-­ grain intake at any level positively reduces the health burdens. The effect has shown at the very low intake of the whole-grain and also with the continuous increase of the whole-grain above 30% of the total energy and above 50% of the total energy and probably above. The most important advantage of this meta-analysis that the presentation of the study supports the notion that the intake of whole-grain has a beneficial advantage for all intake levels. The whole-grain advantage has clearly shown for the whole-grain intake from the low replacement for the refined grains to the moderate replacement at the level of 30% of the total energy intake. The continuous response curves also support the notion that the exchange of the whole-­ grain with dietary energetic items with high fat, high sugar, or even potato that all such replacements might further improve the health status.

References Bautista-Castaño I, Sánchez-Villegas A, Estruch R, Martínez-González MA, Corella D, Salas-­ Salvadó J, Covas MI, Schroder H, Alvarez-Pérez J, Quilez J, Lamuela-Raventós RM, Ros E, Arós F, Fiol M, Lapetra J, Muñoz MA, Gómez-Gracia E, Tur J, Pintó X, Ruiz-Gutierrez V, Portillo-Baquedano MP, Serra-Majem L (2013) Changes in bread consumption and 4-year changes in adiposity in Spanish subjects at high cardiovascular risk. Br J Nutr 110:337–346. https://doi.org/10.1017/S000711451200476X Erkkilä AT, Herrington DM, Mozaffarian D, Lichtenstein AH (2005) Cereal fiber and whole-grain intake are associated with reduced progression of coronary-artery atherosclerosis in postmenopausal women with coronary artery disease. Am Heart J 150:94–101. https://doi.org/10.1016/j. ahj.2004.08.013 Gonzalez-Anton C, Artacho R, Ruiz-Lopez MD, Gil A, Mesa MD (2017) Modification of appetite by bread consumption: a systematic review of randomized controlled trials. Crit Rev Food Sci Nutr 57:3035–3050. https://doi.org/10.1080/10408398.2015.1084490 Huxley R, Mendis S, Zheleznyakov E, Reddy S, Chan J (2010) Body mass index, waist circumference and waist: hip ratio as predictors of cardiovascular riska review of the literature. Eur J Clin Nutr 64:16–22. https://doi.org/10.1038/ejcn.2009.68 Kristensen M, Toubro S, Jensen MG, Ross AB, Riboldi G, Petronio M, Bügel S, Tetens I, Astrup A (2012) Whole-grain compared with refined wheat decreases the percentage of body fat following a 12-week, energy-restricted dietary intervention in postmenopausal women. J Nutr 142:710–716. https://doi.org/10.3945/jn.111.142315 Masley SC, Roetzheim R, Masley LV, McNamara T, Schocken DD (2015) Emerging risk factors as markers for carotid intima media thickness scores. J Am Coll Nutr 34:100–107. https://doi. org/10.1080/07315724.2014.916238 McKeown NM, Yoshida M, Shea NK, Jacques PF, Lichtenstein LH, Rogers G, Booth SL, Saltzman E (2009) Whole-grain intake and cereal fiber are associated with lower abdominal adiposity in older adults. J Nutr 139:1950–1955. https://doi.org/10.3945/jn.108.103762 McKeown NM, Troy LM, Jacques PF, Hoffmann U, O’Donnell CJ, Fox CS (2010) Whole- and refined-grain intakes are differentially associated with abdominal visceral and subcutaneous adiposity in healthy adults: the Framingham Heart Study. Am J Clin Nutr 92:1165–1171. https://doi.org/10.3945/ajcn.2009.29106

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McKeown NM, Hruby A, Saltzman E, Choumenkovitch SF, Jacques PF (2012) Weighing in on whole-grains: a review of evidence linking whole-grains to body weight. Cereal Foods World 57:20–27. https://doi.org/10.1094/CFW-57-1-0020 Mostad IL, Langaas M, Grill V (2014) Central obesity is associated with lower intake of whole-grain bread and less frequent breakfast and lunch: results from the HUNT study, an adult all-population survey. Appl Physiol Nutr Metab 39:819–828. https://doi.org/10.1139/ apnm-2013-0356 Mozaffarian D, Lemaitre RN, Olson JL, Burke GL (2014) Cereal, fruit, and vegetable fiber intake and the risk of cardiovascular disease in elderly individuals. JAMA 289:1659–1666. https://doi. org/10.1001/jama.289.13.1659 Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, Das SR, Ferranti SD, Després J-P, Fullerton HJ, Howard VJ, Huffman MD, Isasi CR, Jiménez MC, Judd SE, Kissela BM, Lichtman JH, Lisabeth LD, Liu S, Mackey RH, Magid DJ, McGuire DK, Mohler ER, Moy CS, Muntner P, Mussolino ME, Nasir K, Neumar RW, Nichol G, Palaniappan L, Pandey DK, Reeves MJ, Rodriguez CJ, Rosamond W, Sorlie PD, Stein J, Towfighi A, Turan TN, Virani SS, Woo D, Yeh RW, Turner MB (2015) Heart disease and stroke statistics—2016 update. Circulation 133:e38–e360. https://doi.org/10.1161/CIR.0000000000000350 Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, Das SR, Ferranti SD, Desprs JP, Fullerton HJ, Howard VJ, Huffman MD, Isasi CR, Jimnez MC, Judd SE, Kissela BM, Lichtman JH, Lisabeth LD, Liu S, Mackey RH, Magid DJ, McGuire DK, Mohler IIIER, Moy CS, Muntner P, Mussolino ME, Nasir K, Neumar RW, Nichol G, Palaniappan L, Pandey DK, Reeves MJ, Rodriguez KJ, Rosamond W, Sorlie PD, Stein J, Towfighi A, Turan TN, Virani SS, Woo D, Yeh RW, Turner MB (2016) Executive summary: heart disease and stroke statistics—2016 update a report from the American Heart Association. Circulation 133:447–454. https://doi.org/10.1161/CIR.0000000000000366 O’Neil CE, Zanovec M, Cho SS, Nicklas TA (2010) Whole-grain and fiber consumption are associated with lower body weight measures in US adults: National Health and Nutrition Examination Survey 1999-2004. Nutr Res 30:815–822. https://doi.org/10.1016/j.nutres.2010.10.013 Petersen KS, Clifton PM, Keogh JB (2014) The association between carotid intima media thickness and individual dietary components and patterns. Nutr Metab Cardiovasc Dis 24:495–502. https://doi.org/10.1016/j.numecd.2013.10.024 Reynolds A, Mann J, Cummings J, Winter N, Mete E, Morenga LT (2019) Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet 393:P434–P445. https://doi.org/10.1016/S0140-6736(18)31809-9 Serra-Majem L, Bautista-Castaño I (2015) Relationship between bread and obesity. Br J Nutr 113:S29–S35. https://doi.org/10.1017/s0007114514003249 Slavin JL (2005) Dietary fiber and body weight. Nutrition 21:411–418. https://doi.org/10.1016/j. nut.2004.08.018 Williams PG (2018) Evaluation of the evidence between consumption of refined grains and health outcomes. Nutr Rev 70:80–99. https://doi.org/10.1111/j.1753-4887.2011.00452.x

Chapter 17

Intervention and Biomarkers

Interventional Studies The whole-wheat intake exerts its activity on human health within years with the limited appearance of biomarkers within a short period. Therefore, the interventional studies aimed to show the advantage of the whole-wheat intake vs the refined products is quite limited and the experimental data that show the effect of whole-­ wheat on biomarkers is limited. Some of these biomarkers appearance listed here. In a study conducted in Pennsylvania, with a group of 25 subjects the effect of whole-wheat intake was tested on blood glucose. The experimental group consumed 187 g/d whole-meal for 12 wks vs a group that consumed refined wheat. The plasma alkylresorcinol was124 nM in the 1st group vs 22 nM and with a decrease in blood glucose of 3.3 mg/dl in the 1st group (Jackson et al. 2014). A similar study conducted in Aberdeen with 73 subjects and an intake of 110 g/d of whole-grain vs refined products for 12  wks. In the 1st group the following changes observed, a decrease in the systolic/diastolic 4/1  mmHg, a decrease of 0.22  mM plasma triglycerides, and a decrease of 1.7  mU/L of plasma insulin observed (Tighe et al. 2012). (a) In a study conducted in Lausanne, subjects consumed whole-grain bread vs refined grain bread, the following changes in blood metabolites observed. A decrease in blood glucose within 2 h after breakfast, a tendency for a decrease in plasma cholesterol, a marked increase in plasma betaine and resorcinol after the breakfast (Ross et al. 2011). (b) In a study conducted in Kuopio and Naples with 54 subjects with metabolic syndrome without diabetes, aged 40–60 y, the cereal products represented about 60–80% of the daily carbohydrate intake. The whole-grain products evaluated vs refined products during 12  wks, showed that a diet based on whole-grain cereal products, compared to a diet based on refined cereals, reduces postprandial insulin and triglyceride plasma concentrations in the individuals with the metabolic syndrome. In the whole-grain group, postprandial insulin response © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_17

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decreased by 29% compared to the baseline, i.e. significantly lower than that observed in the group assigned to the refined cereal diet. The reduced insulin response not paralleled by changes in plasma glucose response, suggesting that the whole-grain diet was able to improve insulin action in the postprandial period. The results suggest a possible effect of whole-grain diet on insulin sensitivity at the liver level, although this not directly measured by the tracer methodology (Giacco et al. 2014). (c) The lack of most of the interventional studies that evaluating the whole-grain to show the superiority and the clear effect of the whole-wheat flour vs the refined flour is presumably the main Achilles Heel of the notion to increase whole-­ grain intake. In a comprehensive meta-analysis of eight studies investigated the effects of the whole-grain on the mortality of the cardiovascular diseases, the reviewers concluded that there is insufficient evidence from the randomized controlled trials to show the effect of the whole-grain diets on the cardiovascular outcomes or major cardiovascular risk factors such as blood lipids and blood pressure. Trials were at unclear or high risk of bias with small sample sizes and relatively short-term interventions, and the overall quality of the evidence was low. There is a need for well-designed, adequately powered randomized controlled trials with longer durations assessing cardiovascular events as well as cardiovascular risk factors (Kelly 2004). The following eight studies (Katcher et al. 2008; Tighe et al. 2012; Maki et  al. 2010; Giacco et  al. 2010; Zhang et  al. 2011; Kristensen et  al. 2012; Jackson et al. 2014; Lankinen et al. 2014) included in the analysis, after exclusion of many others comprised an average of 116 participant and an average duration of 12 wks. There is no reason to run all of these studied in such designs and more importantly to publish a meta-analysis of eight studies comprising extremely small groups of participants and an extremely short period of the trial. Without consideration of all other factors, the period needed for the human organism, to adapt his gut for the whole-grain diet or the refined-flour diet comprises a considerable part of the 12 wks period experimentation. While the non-interventional studies show a positive effect of the whole-wheat the interventional studies fail to show the effect. However, nobody has ever designed and conducted an interventional study with a forecasted capacity to measure the effect of the whole-wheat bread.

The Fecal Output The dietary fiber has well-known beneficial effects on the increase in the fecal weight and decrease of the colon transit time. Both fecal weight and transit time are the key indicators of intestinal and digestive health. Abnormalities serve as a diagnostic criterion for prevalent gastrointestinal disorders, including functional constipation, as well as irritable bowel syndrome and dyspepsia (indigestion). The

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consumption of dietary fiber plays an important role in the adequate function of the gastrointestinal tract and has advocated for improved bowel function. As heterogeneous groups of compounds with unique and overlapping functions, the dietary fibers optimize health and provide the best outcomes when they complement and augment each other. The cereal fiber is known to increase the fecal weight and the transit time, but the impact of the fruits and vegetable on the regularity is largely unknown. The wheat bran increases the stool bulking and shorten the intestinal transit time. The average fecal bulking indices (g feces/g dietary fiber) of the cereal are 4.7 for the wheat fiber, 3.6 for the barley fiber, and 2.1 for the corn fiber. Thus, the wheat fiber might have the best properties to increase the total fecal bulk. Different sources of the dietary fiber are not equal in their functionality and effects on the bowel function. In a survey of many interventional studies for the effectiveness of the different sources of the fiber, the mean increase in fecal weight per g/g fiber of the wheat fiber was 5.4, fruit and vegetables 4.7, gums and mucilage 3.7, cellulose 3.5, oats 3.4, corn 3.3, legumes 2.2, and pectin 1.2. The effect of the wheat fiber on the stool weight is largely attributable to its high resistance to the fermentation by the colonic microbiota, combined with its water binding capacity. The resulting increased the volume of the fecal mass stimulates colonic movement, thereby helping to reduce the transit time and increase the stool frequency (Vries et al. 2015). The normal physiological gut transit time varies between 40 and 60 h. In general, the transit time normalized by increasing the dietary fiber, regardless of the fiber type. The optimal time is between 24 and 48 h, while additional dietary fiber does not appear to alter it. Many Americans believe that they are getting enough fiber, but there is confusion around which foods provide it and how much fiber needed for good health. Adequate intakes of the fiber are associated with reduced risk for morbidities. Of all of the fibers, the composition of those from fruit tends to be more fermentable and soluble than those from vegetable or cereals, which are likely to be the least fermentable and, therefore, have the greatest impact on the fecal wet weight and transit time. A worldwide increase in the incidence of gastrointestinal disorders has created an immediate need to identify safe and effective interventions to maintain regularity. In the US, ~5% of the population suffers from functional constipation (Vries et al. 2016).

 he Blood Alkylresorcinol as a Biomarker T for the Whole-­Wheat Intake Among commonly consumed foods, the alkylresorcinol exclusively found with a substantial amount in the outer parts of wheat and rye, but also in low amounts in barley. Cereal alkylresorcinols comprise a group of 1,3-dihydroxy-5-alkylbenzene homologs with mainly saturated alkyl chains in the range of 15–27 carbon atoms,

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with about 0.5–20% unsaturated and oxygenated homologs depending on the cereal and the cultivar. The bran of wheat and rye contain up to 4000 μg/g and the whole-­ grain wheat, rye and barley contain about 400, 750, and 45 μg/g, respectively. The relative homolog composition is rather consistent within species, but different between species, resulting in C17:0/C21:0 ratios of about 1.0, 0.1 and 0.01 in rye, common wheat and durum wheat, respectively (Fig. 17.1). The large-scale epidemiological studies are presently the ultimate tool to show the effect of the whole-wheat products on the morbidity and the mortality and presumably, such methodology is the ultimate tool for other long-term nutritional effects. The accuracy of such studies is limited because the processed data retrieved from the dietary questionnaires have limited accuracy. However, the wide-scale studies that measure the biomarkers effects of whole-wheat intake are currently unavailable. One of the major challenges in the nutritional epidemiology is obtaining a biomarker that used as the good estimate for the dietary intake because of the error and patience of all types of dietary questionnaires. The whole-grain intake may be particularly a challenging item to measure because of the wide variation in the whole-­ grain content between products, and because there are no universal definitions of the whole-grains or the whole-grain products. The methods commonly used to measure dietary intake in the epidemiologic studies based on the self-reported intake such as food frequency questionnaire. The association between the whole-grain intake and the incidence of colorectal cancer has investigated in many prospective studies with the information on the dietary intake derived from food frequency questionnaires, but the results are inconsistent. The alkylresorcinol may use as a typical biomarker

Alkylresorcinol kernel content 17:0

19:0

21:0

1.2

250

1

200

0.8

150

0.6

100

0.4

50

0.2

0

Wheat

Barley

Rye

C17/C21 rao

Alkylresorcinol μg/g DM

300

0

Chain length Fig. 17.1  Distribution of alkylresorcinol chain-length in cereal kernels (Landberg et  al. 2009; Ross et al. 2003; Geerkens et al. 2015; Andersson et al. 2010a; Andersson et al. 2010b; Chen et al. 2004; Kulawinek et al. 2008; Landberg et al. 2006)

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for whole-wheat consumption (Fig. 9.22) (Knudsen et al. 2014). In human, ~60% of the alkylresorcinols ingested are absorbed from the small intestine, and the proposed route of absorption is via the lymphatic pathway. The elimination of the alkylresorcinols from the plasma is rapid and suggested to comprise extensive hepatic metabolism similar to that of the tocopherols (Marklund et al. 2014). The blood and the other body fluids considered to contain the most reliable biomarkers for the evaluation of the dietary intake in nutritional research such as the alkylresorcinol metabolites (Zhu et al. 2013). The alkylresorcinols, present in several plant families and some algae, mosses, fungi, bacteria, and marine sponges. The ileal recovery of the long-chain homologs (C23:0 and C25:0) was significantly lower than for the shorter homologs (C17:0–C21:0) with about 70–80% of the alkylresorcinols in the blood alkylresorcinols attached to the lipoproteins. Since the composition of the homologs of the alkylresorcinols is rather stable within the cereal species, the C17:0/C21:0 ratios used to determine whether rye or wheat or whether a mixture of the 2 has consumed (Fig. 17.1). The total grain content of the barley is about 70, of wheat 500 and of rye 1100 μg/g dry matter including unsaturated compounds that not presented here (Fig. 17.1). The urinary alkylresorcinols metabolite excretion also increased with the increased intake, but the recovery was lower at the very high alkylresorcinols intakes, suggesting that the alkylresorcinols metabolites in the urine may reflect only modest intake. In human studies, the plasma total alkylresorcinols concentration reached >3 μM and the t1/2 estimated as ~5 h for the total alkylresorcinols with no significant difference for homologs (Landberg et al. 2014). The following examples show the direct relationship between the whole-wheat intake and plasma alkylresorcinol, the capacity of the blood alkylresorcinol to evaluate the risk of colon cancer and to evaluate the effect of the whole-wheat on BMI. In an interventional study conducted in Tuft University, 41 subjects, aged 40–65 y, consumed 207 g/d whole-gain for 6 wks with the increase of the plasma alkylresorcinol of 4–54 ng/mL and with a remarkable decrease of the RMR production (Karl et al. 2017). The effect of the whole-wheat intake on the colon cancer evaluated according to the plasma alkylresorcinol concentration. The relative risk for the colorectal cancer case in patients (n = 1372) and their matched control subjects was calculated for a quartile of plasma alkylresorcinol (9, 28, 65, and 110 nM). The cancer relative risks for the 4th quartile in comparison to the 1st were: all colorectal 0.87; colon 0.85; rectal 0.83; ascending colon 1.09 and descending colon 0.53. The study that managed in 10 European countries strongly supports the marked effect of the whole-­ wheat intake on the relative risk of the descending colon malignancy with no preference calculated for wheat or rye intake. The predictive quality of the plasma alkylresorcinol has clearly shown (Kyrø et al. 2014). In a study conducted in 407 elderly subjects, aged 60–80 y, higher consumption of whole-grain observed according to the plasma alkylresorcinol. Such higher intake has shown to associate with lower BMI in a dose-dependent manner. This inverse association is consistent with the observed beneficial association between the wholegrain intake and the body weight in other observational studies (Ma et al. 2012).

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In a study conducted in Wuhan China, a 19 M population urban area, with 3.2 k subjects (with the three groups of diabetes diagnosed, impaired glucose response, and normal glucose tolerance), the relative risk for the diabetes type 2 occurrence was the highest with the plasma lowest alkylresorcinol, with 1.7 nM alkylresorcinol, and reduced almost linearly ~5 fold at the level of ~55 nM. As the plasma alkylresorcinols concentration is a biomarker of the whole-grain intake, these results clearly show the impact of the whole-grain consumption on the relative risk for diabetes occurrence (Sun et al. 2018). In a cohort study consists of 120 K subjects, presented as a part of Table 15.1, the 522 colorectal cases matched with the controls and analyzed for plasma alkylresorcinol. Of the three measures of the whole-grain intake used in the study, the plasma alkylresorcinol alone was inversely associated with the incidence of the distal colon cancer, whereas whole-grain intake measured by the food frequency questionnaire alone showed no significant association (Knudsen et al. 2014).

DHPPA as Advanced Biomarker The small intestine absorbs the alkylresorcinols at a rate of ~50% and transfers it into the liver where it metabolized to 3-(3, 5-dihydroxyphenyl)-1-propanoic acid (DHPPA) with a half-life of 16 h and 3,5-dihydroxybenzoic acid (DHBA) with a half-life of 10 h. Because alkylresorcinols have a half-life of only 5 h, the DHPPTA is presumably the preferred plasma biomarker for the whole-grain intake (Wierzbicka et al. 2015; Sun et al. 2019). Plasma DHPPA in the European studies are considerably higher than those found in the stroke study (Sun et al. 2019) conducted in China and discussed formerly in Chap. 15 presumably because of the low whole-grain in China. Even so, the difference between the highest plasma DHPPA to the lowest level showed a tremendous marked effect of 0.63 relative risks for stroke incidence between the highest to the lowest quintile (Table 15.1, category 9 – the incidence of stroke). Besides the important evidence for the effect of the whole grain that assessed by high DHPPA on stroke, such the most sensitive approach makes access to identify the superior biomarkers that affected by high grain intakes such as immune responses or telomere attrition. Such an experimentation frame that requires an only limited subject number, might become a very sensitive methodology for the quantification of the whole-­ wheat intake. By using sensitive biomarkers such a frame might be employed for the development of superior wheat products such as: (a) The advanced milling technique. (b) Baking conditions for the lower destruction of sensitive micronutrients. (c) Superior endosperm composition for diabetic patients. (d) The selected combination of polyphenol and related micronutrients. (e) Selected functionality of the whole-wheat for ocular burdens.

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(f) The advancement in the replacing of whole-wheat for other starchy items such as potato, rye, oats, or corn. (g) The effect of the whole wheat on autophagy and apoptosis. A massive increase in the inclusion of whole-wheat products into our menu requires some measures to fulfill the goal of marked improvement in health outcomes which foreseen by such a maneuver. The total antioxidant capacity is a pivotal component of the whole-wheat products in the capacity to reduce morbidity. No standard method is available for the total antioxidant capacity in the serum. So far, the efforts to establish standard methods for total antioxidant capacity aimed to cover many food items. Presumably, no studies have tried to establish a standard method for wheat-products alone and for the total antioxidant capacity in the serum as affected by the intake of whole-wheat products. Because wheat is the main food item in our menu, it should deserve particular standard methods.

The Direct Effects of Alkylresorcinol Micromolar alkylresorcinols concentration showed a long list of human cancer lines inhibition such as the colon, breast, lung, central nervous system, adenocarcinoma, hepatocarcinoma, cervix squamous carcinoma, and ovarian cancer. Except for the well-known quality of the plasma alkylresorcinol as a biomarker for the consumption of the whole-grain wheat and rye, the alkylresorcinol affects many cellular processes regulated by the enzymes, affects genotoxicity, and suppresses the adipocyte lipolysis. The alkylresorcinol has a high affinity to the erythrocyte membranes, and exert indirect anti-oxidant activity, and most importantly has a cytotoxic effect on the cancer cell lines. The chain length of alkylresorcinol is important for the alkylresorcinol ability to inhibit the cancer growth, with shorter chains like C13:0, C15:0, and C17:0 appearing to have the highest potency of cancer inhibition. Since the rye has a higher ratio of the short chain alkylresorcinol it might have a higher capacity for anticancer effect (Kruk et al. 2017). However, the vast majority of the alkylresorcinol present in the rye bran, therefore refined flour rye contains a lower content of alkylresorcinol (Ross et al. 2003). The direct effect of the alkylresorcinol on the cancer cells deserves particular attention for the content and the composition of the alkylresorcinols in the wheat kernel. The high variations of the plasma alkylresorcinol between the different populations and between various cultivars and varieties leave a wide room to expand the limited knowledge of this issue that may integrate with the targeted breeding to develop wheat with the optimal alkylresorcinol composition and concentration.

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References Andersson AAM, Åman P, Wandel M, Frølich W (2010a) Alkylresorcinols in wheat and rye flour and bread. J Food Compos Anal 23:794–801. https://doi.org/10.1016/j.jfca.2010.03.012 Andersson AAM, Kamal-Eldin A, Åman P (2010b) Effects of environment and variety on alkylresorcinols in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9299–9305. https://doi.org/10.1021/jf904526d Chen Y, Ross AB, Åman P, Kamal-Eldin A (2004) Alkylresorcinols as markers of whole-grain wheat and rye in cereal products. J Agric Food Chem 52:8242–8246. https://doi.org/10.1021/ jf049726v Geerkens CH, Matejka AE, Carle R, Schweiggert RM (2015) Development and validation of an HPLC method for the determination of alk(en)ylresorcinols using rapid ultrasound-assisted extraction of mango peels and rye grains. Food Chem 169:261–269. https://doi.org/10.1016/j. foodchem.2014.08.001 Giacco R, Clemente G, Cipriano D, Luongo D, Viscovo D, Patti L, Marino LD, Giacco A, Naviglio D, Bianchi MA, Ciati R, Brighenti F, Rivellese AA, Riccardi G (2010) Effects of the regular consumption of wholemeal wheat foods on cardiovascular risk factors in healthy people. Nutr Metab Cardiovasc Dis 20:186–194. https://doi.org/10.1016/j.numecd.2009.03.025 Giacco R, Costabile G, Pepa GD, Anniballi G, Griffo E, Mangione A, Cipriano P, Viscovo D, Clemente G, Landberg R, Pacini G, Rivellese AA, Riccardi G (2014) A whole-grain cereal-­ based diet lowers postprandial plasma insulin and triglyceride levels in individuals with metabolic syndrome. Nutr Metab Cardiovasc Dis 24:837–844. https://doi.org/10.1016/j. numecd.2014.01.007 Jackson KH, West SG, Heuvel JPV, Jonnalagadda SS, Ross AB, Hill AM, Grieger JA, Lemieux SK, Kris-Etherton PM (2014) Effects of whole-and refined grains in a weight-loss diet on markers of metabolic syndrome in individuals with increased waist circumference: a randomized controlled-­feeding trial. Am J Clin Nutr 100:577–586. https://doi.org/10.3945/ajcn.113.078048 Karl JP, Meydani M, Barnett JB, Vanegas SM, Goldin B, Kane A, Rasmussen H, Saltzman E, Vangay P, Knights D, Chen CO, Das SK, Jonnalagadda SS, Meydani SN, Roberts SB (2017) Substituting whole-grains for refined grains in a 6-wk randomized trial favorably affects energy-balance metrics in healthy men and postmenopausal women. Am J Clin Nutr 105:589– 599. https://doi.org/10.3945/ajcn.116.139683 Katcher HI, Legro RS, Kunselman AR, Gillies PJ, Demers LM, Bagshaw DM, Kris-Etherton PM (2008) The effects of a whole-grain-enriched hypocaloric diet on cardiovascular disease risk factors in men and women with metabolic syndrome. Am J Clin Nutr 87:79–90 Kelly S, Brynes A, Frost G, Lang R, Whittaker V, Summerbell C (2004) Wholegrain cereals for coronary heart disease. Cochrane Database Syst Rev. https://doi.org/10.1002/14651858. cd005051 Knudsen MD, Kyro C, Olsen A, Dragsted LO, Skeie G, Lund E, Åman P, Nilsson LM, Bueno-De-­ Mesquita HB, Tjonneland A, Landberg R (2014) Self-reported whole-grain intake and plasma alkylresorcinol concentrations in combination in relation to the incidence of colorectal cancer. Am J Epidemiol 179:1188–1196. https://doi.org/10.1093/aje/kwu031 Kristensen M, Toubro S, Jensen MG, Ross AB, Riboldi G, Petronio M, Bügel S, Tetens I, Astrup A (2012) Whole-grain compared with refined wheat decreases the percentage of body fat following a 12-week, energy-restricted dietary intervention in postmenopausal women. J Nutr 142:710–716. https://doi.org/10.3945/jn.111.142315 Kruk J, Aboul-Enein B, Bernstein J, Marchlewicz M (2017) Dietary alkylresorcinols and cancer prevention: a systematic review. Eur Food Res Technol 243:1693–1710. https://doi. org/10.1007/s00217-017-2890-6 Kulawinek N, Jaromin A, Kozubek A, Zarnowski R (2008) Alkylresorcinols in selected Polish rye and wheat cereals and whole-grain cereal products. J Agric Food Chem 56:7236–7242

References

361

Kyrø C, Olsen A, Landberg R, Skeie G, Loft S, Åman P, Leenders M, Dik VK, Siersema PD, Pischon T, Christensen J, Overvad K, Boutron-Ruault MC, Fagherazzi G, Cottet V, Kühn T, Chang-Claude J, Boeing H, Trichopoulou A, Bamia C, Trichopoulos D, Palli D, Krogh V, Tumino R, Vineis P, Panico S, Peeters PH, Weiderpass E, Bakken T, Åsli LA, Argüelles M, Jakszyn P, Sánchez MJ, Amiano P, Huerta JM, Barricarte A, Ljuslinder I, Palmqvist R, Khaw KT, Wareham N, Key TJ, Travis RC, Ferrari P, Freisling H, Jenab M, Gunter MJ, Murphy N, Riboli E, Tjønneland A, Bueno-De-Mesquita HB (2014) Plasma alkylresorcinols, biomarkers of whole-grain wheat and rye intake, and incidence of colorectal cancer. J Natl Cancer Inst 106:djt352. https://doi.org/10.1093/jnci/djt352 Landberg R, Kamal-Eldin A, Andersson R, Åman P (2006) Alkylresorcinol content and homologue composition in durum wheat (Triticum durum) kernels and pasta products. J Agric Food Chem 54:3012–3014. https://doi.org/10.1021/jf0530805 Landberg R, Andersson AAM, Åman P, Kamal-Eldin A (2009) Comparison of GC and colorimetry for the determination of alkylresorcinol homologues in cereal grains and products. Food Chem 113:1363–1369. https://doi.org/10.1016/j.foodchem.2008.08.072 Landberg R, Marklund M, Kamal-Eldin A, Åman P (2014) An update on alkylresorcinols - occurrence, bioavailability, bioactivity and utility as biomarkers. J Funct Foods 7:77–89. https://doi. org/10.1016/j.jff.2013.09.004 Lankinen M, Kolehmainen M, Jääskeläinen T, Paananen J, Joukamo L, Kangas AJ, Soininen P, Poutanen K, Mykkänen H, Gylling H, Oreŝiĉ M, Jauhiainen M, Ala-Korpela M, Uusitupa M, Schwab U (2014) Effects of whole-grain, fish and bilberries on serum metabolic profile and lipid transfer protein activities: a randomized trial (Sysdimet). PLoS One 9:e90352. https://doi. org/10.1371/journal.pone.0090352 Ma J, Ross AB, Shea MK, Bruce SJ, Jacques PF, Saltzman E, Lichtenstein AH, Booth SL, McKeown NM (2012) Plasma alkylresorcinols, biomarkers of whole-grain intake, are related to lower BMI in older adults. J Nutr 142:1859–1864. https://doi.org/10.3945/jn.112.163253 Maki KC, Beiseigel JM, Jonnalagadda SS, Gugger CK, Reeves MS, Farmer MV, Kaden VN, Rains TM (2010) Whole-grain Ready-to-Eat oat cereal, as part of a dietary program for weight loss, reduces low-density lipoprotein cholesterol in adults with overweight and obesity more than a dietary program including low-fiber control foods. J Am Diet Assoc 110:205–214. https://doi. org/10.1016/j.jada.2009.10.037 Marklund M, Strömberg EA, Lærke HN, Knudsen KEB, Kamal-Eldin A, Hooker AC, Landberg R (2014) Simultaneous pharmacokinetic modeling of alkylresorcinols and their main metabolites indicates dual absorption mechanisms and enterohepatic elimination in humans. J Nutr 144:1674–1680. https://doi.org/10.3945/jn.114.196220 Ross AB, Shepherd MJ, Schüpphaus M, Sinclair V, Alfaro B, Kamal-Eldin A, Åman P (2003) Alkylresorcinols in cereals and cereal products. J Agric Food Chem 51:4111–4118. https://doi. org/10.1021/jf0340456 Ross AB, Bruce SJ, Blondel-Lubrano A, Oguey-Araymon S, Beaumont M, Bourgeois A, Nielsen-­ Moennoz C, Vigo M, Fay LB, Kochhar S, Bibiloni R, Pittet AC, Emady-Azar S, Grathwohl D, Rezzi S (2011) A whole-grain cereal-rich diet increases plasma betaine, and tends to decrease total and LDL-cholesterol compared with a refined-grain diet in healthy subjects. Br J Nutr 105:1492–1502. https://doi.org/10.1017/S0007114510005209 Sun T, Rong Y, Hu X, Zhu Y, Huang H, Chen L, Li P, Li S, Yang W, Cheng J, Yang X, Yao P, Hu FB, Liu L (2018) Plasma alkylresorcinol metabolite, a biomarker of whole- grain wheat and rye intake, and risk of type 2 diabetes and impaired glucose regulation in a Chinese population. Diabetes Care 41:440–445. https://doi.org/10.2337/dc17-1570 Sun T, Zhang Y, Huang H, Wang X, Zhou L, Li S, Huang S, Xie C, Wen Y, Zhu Y, Hu X, Chen L, Li P, Chen S, Yang W, Bao W, Hu FB, Cheng J, Liu L (2019) Plasma alkylresorcinol metabolite, a biomarker of whole-grain wheat and rye intake, and risk of ischemic stroke: a case-control study. Am J Clin Nutr 109:1–7. https://academic.oup.com/ajcn/article-abstract/109/2/1/5308616

362

17  Intervention and Biomarkers

Tighe P, Duthie G, Vaughan N, Brittenden J, Simpson WG, Duthie S, Mutch W, Wahle K, Horgan G, Thies F (2012) Effect of increased consumption of whole-grain foods on blood pressure and other cardiovascular risk markers in healthy middle-aged persons: a randomized controlled trial. Am J Clin Nutr 92:733–740. https://doi.org/10.3945/ajcn.2010.29417 Vries JD, Miller PE, Verbeke K (2015) Effects of cereal fiber on bowel function: a systematic review of intervention trials. World J Gastroenterol 21:8952–8963. https://doi.org/10.3748/ wjg.v21.i29.8952 Vries JD, Birkett A, Hulshof T, Verbeke K, Gibes K (2016) Effects of cereal, fruit and vegetable fibers on human fecal weight and transit time: a comprehensive review of intervention trials. Nutrients 8:130. https://doi.org/10.3390/nu8030130 Wierzbicka R, Wu H, Franek M, Kamal-Eldin A, Landberg R (2015) Determination of alkylresorcinols and their metabolites in biologicalsamples by gas chromatography–mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 1000:120–129. www.elsevier.com/locate/ chromb Zhang G, Pan A, Zong G, Yu Z, Wu H, Chen X, Tang L, Feng Y, Zhou H, Chen X, Li H, Hong B, Malik VS, Willett WC, Spiegelman D, Hu FB, Lin X (2011) Substituting white rice with brown rice for 16 weeks does not substantially affect metabolic risk factors in middle-aged chinese men and women with diabetes or a high risk for diabetes. J Nutr 141:1685–1690. https://doi. org/10.3945/jn.111.142224 Zhu Y, Shurlknight KL, Chen X, Sang S (2013) Identification and pharmacokinetics of novel alkylresorcinol metabolites in human urine, new candidate biomarkers for whole-grain wheat and rye intake. J Nutr 144:114–122. https://doi.org/10.3945/jn.113.184663

Chapter 18

The Effect of the Yellow Pigments on the Ocular Functions, the Effect on the Cognition, and the Development

The carotenoid pigment family comprises >750 members that are present in plants, bacteria, and fungi and constitutes the second most abundant class of natural pigments. All carotenoids are derived from phytoene, and most of them are C40 polyenes. They required for the correct assembly of the photosystems and light-harvesting complexes, and as photoprotective compounds by limiting oxidative damage (Schulthess and Schwember 2013). Total carotenoids usually estimated by the quantifying of the total yellow pigments based on the spectrophotometric determination (Fu et  al. 2017). The carotenoids mainly classified into two major groups according to whether the carbon chain contains oxygen residues (xanthophylls) or not (carotenes). The most common yellow xanthophyll pigments are lutein and zeaxanthin. The most common carotenes are β-carotene and the red pigment lycopene (Ravel et al. 2013). The cereal literature defines carotenoids with particular interest for the durum wheat because of the yellow pigments responsible for the yellow color of semolina and the end-products such as pasta and couscous Fu et al. 2017). Except for the well known β-carotene present in the yellow-pigments of the wheat kernel, it also contains lutein and the zeaxanthin (Figs. 8.6 and 8.7). Along with their conversion isomer meso-zeaxanthin (Fig. 8.8), they are the major constituents of the macular pigment, a mixture of compounds concentrated in the macula region of the retina that is responsible for fine-feature vision. They are also concentrated in some brain regions and found to improve the human cognition, to improve the early development, and to decrease the dementia prevalence. Given their accumulation in the retina, the role of lutein and zeaxanthin in the eye health has investigated with a particular focus on how consumption of these carotenoids may prevent and/or slow the progression of the vision impairments. A clear effect found for the alleviating of the cataract and the AMD that is the leading cause of blindness in the older adults in the US (Eisenhauer et al. 2017). The retinal pigment cells are very active metabolically, and with a high protein turnover rate. In the higher animals, the lutein and the zeaxanthin present in the lipophilic fractions and the blood by the lipoproteins and distributed equally between the LDL and the HDL in contrast to the hydrocarbon carotenoids that found mainly in the LDL. The lutein concentrations in the human © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_18

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tissues stay at the range of 1.1–1.5 μM and in the retina at the much higher concentration of 0.1–1 mM (Krinsky et al. 2003). Any metabolic disturbance altering the delicate oxidant/anti-oxidant balance disrupts their functioning. With their accumulation, up to ×1000 higher for the lutein concentration than in the other tissues, they might be most sensitive for a low intake (Manikandan et al. 2016). The retinal pigment epithelial cells monolayer, interposed between the retinal microcirculation and the neuroretinal/photoreceptor layers, is essential for the maintaining of the retinal integrity and the photoreceptor survival. The retinal pigment epithelial cells exposed to the host of the physiological stressors, including light, hyperoxia, reactive oxygen species generation, changes in blood glucose, and, in disease, ischemia, and hypoxemia. In humans, the retinal pigment epithelial cells contain the molecular pathways for the visual retinoid cycle and uptake, metabolism, and transfer of dietary lutein and its isomer zeaxanthin. The low or the decreased retinal lutein/zeaxanthin levels, compared to the normal eye, found in both ischemic retinopathies and AMD (Gong et al. 2017). The yellow pigments of the wheat kernel are mainly present in the bran fraction with a low concentration in the starchy endosperm. Thus, the refined flour contains only a small portion of these pigments (Table 4.3). The culinary and the esthetic demands for the pure and the white flour have caused within the last generations a further decrease in the content of the flour yellow-pigments by a continuous wheat breeding of the bread wheat and elimination of the “un-esthetic” darker colors. In one example, bread wheat contained 2.3 vs. 8.3 μg/g dry matter total carotenoids in comparison to hulled emmer wheat (Shewry and Hey 2015). With the increase in the incidence of the AMD and the cataract that mainly expanded by the increase in the lifespan, the adequate intake of the yellow pigments, become more and more crucial to protect our vision and cognition. As the wheat-flour refined for the brightest color the yellow pigments of the carotenoids, the xanthophylls, and the lutein concentration have further reduced. While the low-­ extraction white flour has some advantage in the dough rising, the brightness of the flour has all nutritional drawbacks. The entire carotenoid biosynthetic pathway still exists in the wheat grains, so varieties high in the β-carotene and/or the other carotenoids can reintroduce if and when, education in nutrition creates the demand for the yellow pigments (Graham and Rosser 2000; Clarke et al. 2011; Olmedilla et al. 2001; Abdel-Aal et al. 2013; Abdel-Aal et al. 2002). In the whole-wheat flour, the content of the lutein, the xanthophylls, and the carotenes are two to sixfold higher than in the 70% extracted flour (Table 4.3). In the collected data, the ratio between the highest content of the kernel yellow pigments is up to ×50 higher for the highest content to the lowest one (Table 8.2). The human macula contains an additional carotenoid, the meso-zeaxanthin (Fig. 8.8), which is a stereoisomer of the zeaxanthin that converted from the lutein within the retina (Jia et al. 2017) but rarely exists in some animal products of the human diet (Arunkumar et al. 2018). The insufficient intake of the yellow-pigments harms the vision and in particular in the elderly. As for 2016, 29% of the US population aged >50 y affected by the vision impairment with the following distribution, %: cataract 66, diabetic

18  The Effect of the Yellow Pigments on the Ocular Functions, the Effect…

365

retinopathy 21, glaucoma 7, and AMD 6. The cataract incidence continuously elevates with aging thus more than a ×2 increase in the prevalence of the vision impairment observed between the population aged >80  y in comparison to the population of 76–79 y. In the US whites aged >80 y with the vision impairment, the prevalence is, %: cataract 66, diabetic retinopathy 21, AMD 14, and glaucoma 7 (NIH-US National Eye Institute  - Age-Related Eye Diseases in America). In China, at the age of 85–89 y, the cataract prevalence is 75% (Song et al. 2018). Besides the major impairment in life quality and productivity, the vision impairment highly related to the marked increase in the relative risk of the major health burdens and the NCD. In the US population aged >65 y, higher relative risks of the morbidity burdens and the NCD have observed in subjects with the vision impairment. The relative risk values for the population with the vision impairment in a comparison to the other subjects: weak/failing kidney 2.3, stroke 2.0, hearing impairment 1.9, arthritis 1.7, heart disease 1.6, asthma 1.6, chronic obstructive pulmonary disease (COPD) 1.6, diabetes 1.5, depression 1.5, hypertension 1.4, high cholesterol 1.3, hepatitis 1.3, and cancer 1.2 (Crews et al. 2017). Presumably, most of the nutritional ingredients with an alleviative effect on the NCD might have also an alleviative effect on infectious diseases but with much less available data. When the whole-wheat bread consumed routinely, it supplies a steady influx of the yellow-pigments that keeps an adequate level of lutein and the zeaxanthin in human tissues. Restoration of the retracted yellow pigments and a possible breeding increase in their content might have a visible effect on human welfare. We have formerly shown, the marked effect of the whole-wheat bread on the decrease in the relative risks on the long list of many prevalent morbidities. The statistical list has supported by hundreds of reputed studies (Table 15.2). However, we could not locate data for such an effect of the whole-wheat intake on the decrease in the incident of the vision impairment. The extreme lower content of the yellow pigments in the bread wheat, in comparison to the einkorn and durum kind of wheat, may elucidate the absence of such data (Leenhardt et al. 2006), The lutein and the zeaxanthin have a particular role in the eye integrity because they absorb specific light wavelengths that protect the eyes. Carotenoids may guard against certain types of cancer by limiting the abnormal growth of cells and/or by the enhancing of gap-­ junctional communication. The total carotenoids content of the wheat flour with the 100% extraction rate (whole-wheat flour) is ~×6 than the flour with 70% extraction rate (Table 4.3). Because the impaired vision is a most common burden that derived from the impaired metabolism, the effect of the whole-wheat on such an impairment likely to occur even the data for the direct effect of the whole-bread intake on the vision morbidities scarcely available (Eggersdorfer and Wyss 2018). In some of the wheat varieties and cultivars, the “yellow pigments” found at a comparatively higher concentration in the whole-wheat flour and at a low concentration in the refined flour have shown to affect some health burdens such as cognition impairment and the four vision impairments mentioned above (cataract, diabetic retinopathy, glaucoma, and AMD). Some limited data for the direct effect of the “yellow pigments” on the human vision is available.

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Of particular interest are the epidemiological studies showing an inverse correlation between the progression of the AMD and cataract and the high intake of the lutein and the zeaxanthin rich-vegetables, being both pigments present in high concentration at the macula in the human retina and the primate retina. Cereals considered ideal elements for the use in the bio-fortification strategies. However. Presently restoration should be conducted before biofortification. An essential step for the development of carotenoid biofortified crops is the complete characterization of the carotenoid profile contained in the vegetables, allowing this an adequate knowledge of their metabolism, which can use for the selection and breeding of the new cultivars (Mellado-Ortega and Hornero-Méndez 2015). Some of the wheat species such as einkorn, durum, and corn hold potential for the developing high-lutein staple foods. While the lutein content ranges from 5.4 to 7.4 μg/g in high-lutein wheat species its content is ~21.9 μg/g in the corn (Abdel-Aal et al. 2013).

Age-Related Macular Degeneration (AMD) The prevalence of the AMD is much lower than that of the cataract but without the readily available cure such as the cataract surgery. AMD is the main cause of blindness in the developed world. It represents a progressive chronic disease of the central retina. Owing to the sharp rise in the elderly population, the disease has brought a huge burden on the health care system and had a profound impact on the quality of life and independence of older individuals. A further sharp increase in the AMD prevalence forecasted. Although the pathogenesis of the AMD poorly understood, oxidative stress has implicated as a major contributing factor. The cause of AMD is complex, and many risk factors have implicated including age, genetics, the dietary style, and other environmental risk factors. Epidemiological studies suggested that consumption of the lutein and the zeaxanthin may associate with the lower risk of AMD (Jia et al. 2017). The prevalence rates for the late forms of the disease increase from 80 y and for the early AMD from ~1.5% in the Caucasians aged 45 y up to >25% at the age of >80 y (Carneiro and Andrade 2017). The relative risk for advanced AMD in people >50 y was calculated in nine epidemiological studies for the alleviative effect of the yellow pigments (Table 18.1). Each study was calculated for the incidence ratio between the higher to the lower intake or the higher and the lower blood concentration of the yellow pigments. The two intake calculation based on the dietary questionnaires with the relative risk median of 0.71. In four evaluations the relative risk calculated according to the plasma carotenoids, the relative risks of 0.07–0.31 evaluated. Such values show extremely high efficiency with no accepted average. In the other three evaluations of the effect of the plasma carotenoids, a median of 0.57 has calculated. The relative risk range in the nine studied presented is too high to calculate a global average or a median for all studies.

Study Advanced AMD Ma et al. (2012) Wu et al. (2015) Delcourt et al. (2006) Delcourt et al. (2006) Delcourt et al. (2006) Delcourt et al. (2006) Wu et al. (2015) Wu et al. (2015) Wu et al. (2015) Total subject number

Period

2006–2008 1986–2010 2002–2004 2002–2004 2002–2004 2002–2004 1986–2010 1986–2010 1986–2010

Site

4 studies US France France France France US US US

120 126 0.6 0.6 0.6 0.6 126 126 126 247 K

Subjects K

50–90 >60 >60 >60 >60 50–90 50–90 50–90

Age Lutein+zeaxanthin All carotenoids quintile Lutein Zeaxanthin Lutein+zeaxanthin α-Carotene Lutein/zeaxanthin score All carotenoids score All carotenoids quintile

Evaluated compound Intake Intake Plasma Plasma Plasma Plasma Plasma Plasma Plasma

Predictor

Low/high μΜ μΜ μΜ μΜ μg/L μg/L Low/high

unit

Low 1 0.15 0.03 0.2 0.03 116 5 1

Range High 5 0.45 0.011 0.6 0.22 236 25 5

0.74 0.68 0.31 0.07 0.21 0.30 0.47 0.57 0.64

RR

Table 18.1  The effect of the yellow pigments on AMD: The decrease in the relative risk (RR) of the incidence of advanced AMD with the plasma concentration or the higher intake of dietary carotenoids in comparison to the lower level

Age-Related Macular Degeneration (AMD) 367

368

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There is clear evidence of a protective role of the lutein and the zeaxanthin against age-related macular degeneration, the major cause of blindness in the elderly. Moreover, they also accumulate in the brain tissue and increasing evidence provide cognitive benefits. Likewise, the mechanisms of the action of lutein and the zeaxanthin to the cognitive function, though not fully elucidated, may relate to their anti-oxidant and anti-inflammatory capacities among others (Rodriguez-Concepcion et al. 2018). The well-defined effect of the yellow pigment to preserve eye integrity has attracted research funds and researches to investigate the effect of the supplementation of high quantities of synthetic yellow pigments on eye integrity. However, the indication of the routine supplementation of the synthetic carotenoids for the public by a leading authority required much more authoritative evidence. There is a crucial need to prove that the synthetic compounds exert the same alleviative effects as for the natural compounds without causing adverse effects. The optimal indication of each yellow compound should precisely be defined. Both evaluations should be carried on by human experimentation while such animal studies have only limited support. The most prevailed and the accepted methodology to evaluate the upper-safe-limit and the alleviative quality of the synthetic compounds by short terms animal experimentation of follow-up does not seem like a serious approach while the nadir ranges have not evaluated (Dror et al. 2018).

The Effect on the Cataract The cataract is an opacification of the lens that leads to decreased visual acuity and functional disability. The cataract is a common and significant cause of visual impairment and the leading cause of preventable blindness worldwide and one of the most common causes of blindness (Anderson et al. 2018). A recent WHO survey showed that 51% of cases of the blindness and 33% of cases of the visual impairment worldwide caused by the cataract (Zhu et al. 2017). In the US prevalence of 68% has described for the age >80 (NIH-US National Eye Institute  - Cataracts Defined Tables). The human lens contains lutein and zeaxanthin as the only carotenoids. These pigments localized in the more metabolically active epithelial and cortical layers of the lens (Krinsky et al. 2003). The effect of the intake of the yellow pigments, the blood level of the yellow pigments, and the effect of vitamin E on the decrease in the cataract incidence (Table 18.2) shows a mark reduction in people >45 y. The relative risk for each evaluation has calculated for the incidence ratio between the higher and the lower intake or the higher and the lower blood concentration. The three intake calculations evaluated according to the dietary questionnaires. A median of 0.69 calculated for all the three calculations which supported by the relatively

1992–2011

1986–1994 1992–2001 2002–2004 2002–2004 2001–2004 2001–2004 2006–2008

US US France France

France India

Period

Site

9 studies

18 4.8 2.6 0.8 1.8 1.8

Subjects K

45–75 50–80 >60 >60 50–79 50–79 >60

Age

Vitamin E Median of the studies

Lutein and zeaxanthin Lutein and zeaxanthin Lutein+zeaxanthin Zeaxanthina Lutein+zeaxanthin Lutein+zeaxanthin Lutein+zeaxanthin

Evaluated compound

Blood

Intake Intake Plasma Plasma Intake Serum Blood

Predictor

μΜ μΜ mg/d μΜ 2 studies

mg/d

Unit

Low

1.3 Low 0.2 0.03 0.8 0.04

Range

High

6.9 High 0.6 0.10 2.9 0.19

0.75 0.69

0.81 0.79 0.65 0.57 0.77 0.68 0.69

RR

a

Besides the higher plasma concentration of the lutein, α-carotene, β-carotene, and β-cryptoxanthin showed a remarkable decrease in the relative risk for the cataract incidence but the statistical analysis did not reach accepted level

Vitamin E Cui et al. (2013)

Study Cataract Yellow pigments Brown et al. (1999) Glaser et al. (2015) Delcourt et al. (2006) Delcourt et al. (2006) Moeller et al. (2008) Moeller et al. (2008) Liu et al. (2014)

Table 18.2  The decrease in the relative risk (RR) of the cataract incidence with the increase in the dietary intake or the blood concentration of lutein, zeaxanthin and vitamin E

The Effect on the Cataract 369

370

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low variability between them. In all of the studies, the intake of the natural carotenoids considered with no synthetic carotenoids which might contain some compounds with different configuration and not comprising the same ratios between the different isomers as for the natural products.

Glaucoma and the Diabetic Retinopathy These two burdens with a total prevalence of 28% in all vision impairments of the US people >80 also affected by the “yellow-pigments”. The lutein and the zeaxanthin help to prevent the development and the progression of glaucoma and the diabetic retinopathy, which are more common in the people with diabetes. Glaucoma is a group of conditions that cause optic neuropathy and the degeneration of the retinal ganglion cells and their axons, leading to reduced visual sensitivity, particularly in the peripheral field of the vision. It is a long-term, chronic disease with no present cure and is the leading cause of irreversible blindness in the world because many people continue to have progressive, severe vision loss despite treatment to lower the eye pressure (Mares 2016). The marked decrease in the relative risks for the cataract and AMD strongly supports the notion of the whole-wheat bread for well-­ being. The whole-bread contains a much higher content of the lutein and the zeaxanthin than the flour-refined bread. With a routine consumption of the whole-bread, an adequate supply may raise the blood lutein and zeaxanthin to the level with a lower relative risk of the vision impairment. The yellow pigments derived from the plants contained a natural mixture of many isomers as lutein has 3, and zeaxanthin 2 chiral centers (Jia et al. 2017). The main yellow pigments in the eye are lutein and zeaxanthin, present at lower content in the refined wheat flour but with a moderate amount in the whole-wheat flour. The yellow pigments that were withdrawn from our bread are a typical instance of the deterioration in our menu fabricated by the most unwise culinary trend. The exhausting of the yellow pigments initiated by the flour refining and proceeded by the continuous wheat-bread breeding to get the white flours by the market demand. Consequently, a decrease in the yellow-­pigments intake affected an uncounted number of vision impairments in the Western population.

The Effect of the Yellow Pigments on the Cognition Presumably, one of the most compelling issues of the whole-bread is the relationship between the lutein and the zeaxanthin and visual, and the cognitive health and the long-way depletion track of the bread-wheat breeding to get rid of the “unpleasant”

The Effect of the Yellow Pigments on the Cognition

371

color of the yellow-pigments. While a variety of evidence supports their role in vision, the role in the cognition has only limited support (Johnson 2014). In part, the beneficial effects of the lutein thought to be attributable to its anti-oxidant and anti-­ inflammatory properties. Given that the eye is an extension of the neural system, lutein increasingly recognized as having a role in the cognitive functions. In the pediatric brains, the relative contribution of the lutein to the total carotenoids is twice that found in the adults, accounting for more than half of the concentration of the total carotenoids. The greater proportion of the lutein in the pediatric brain suggests a need for the lutein during the neural development as well. Apart from the cognitive function relationships with the macular pigments, there is less evidence for a relationship between the zeaxanthin and the cognition. Some recent studies evinced a possible role for the lutein and the zeaxanthin in the cognitive function. Several studies have shown that cognitive impairment being age-related eye diseases, suggesting that similar factors may be involved. These observations are in line with the view that the vision and the cognition are not easily separable. Among the carotenoids, the lutein and the zeaxanthin are the only 2 that cross the blood-retina barrier to form the macular pigments in the eye. The lutein is the dominant carotenoid in the human brain tissue. Only lutein was consistently associated with a wide range of cognitive measures that included executive function, language, learning, and memory, which are all associated with the specific brain regions. Lutein and zeaxanthin may benefit cognitive function in older adults by increasing neurobiological efficiency in brain regions at the risk for the age-related deterioration. The lutein may influence the differentiation of the pluripotent neural stem cells. The whole-kernel contains a higher content of lutein and zeaxanthin by two to four fold and contains 3.5 lutein and 0.63 zeaxanthin μg/g (Table 8.2) (Jia et  al. 2017). These two ingredients and other carotenes have an important role in brain integrity. The lutein and the zeaxanthin appeared to buffer the cognitive decline in the verbal learning task with significant interactions during learning. The lutein and the zeaxanthin supplementation appears to benefit the neurocognitive function by enhancing cerebral perfusion, even if consumed for a discrete period in late life (Lindbergh et al. 2018). The whole-wheat consumption at the upper level of intake supplies a considerable part of the lutein and the zeaxanthin intakes. With an intake of ~30% whole-­ wheat of the total energy at ~150  g/d, the average intake of the lutein and the zeaxanthin is 520 and 90 μg/d, respectively (Table 8.2). Even when the whole-bread covers all wheat intake, some other food items supply the considerable part of the yellow pigment intake such as the egg yolk with an intake of ~20 g/d that supplies ~160 μg/d lutein. Some food items contain higher lutein concentrations (Abdel-Aal et  al. 2013) but with a much lower regular intake. Thus, ample intake of the ­whole-­wheat bread supplies the majority of the yellow-pigments and has the major effect on their plasma concentrations and more importantly on the content of the macular pigments. Thus, a high value of macular pigment measurements may mirror the high intake of the whole-bread. In the two most interesting publications conducted in the ongoing population-­ based study (3-City Bordeaux Study) on the vascular risk factors for dementia, the

372

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effects of the dietary lutein and the zeaxanthin have shown. In a sample consisted of 184 persons, 82 y, 68% females, published on 2018, higher macular pigment optical density and plasma (apparently mirrors long-term higher intakes of the yellow-­ pigments), and lutein and zeaxanthin concentrations were both significantly associated with the higher cognitive performances (Ajana et  al. 2018). In a sample of non-demented older participants conducted during 9.5 y, the plasma concentration of the carotenoids evaluated versus dementia occurrence. In this cohort study, the total xanthophylls, but not total carotenes, was significantly associated with a reduced risk of all-cause dementia. Among the xanthophylls, only higher lutein concentrations related to a significantly decreased risk of dementia. In the human brain, lutein and zeaxanthin are the main carotenoids, contributing to >0.67 of total brain carotenoids, and are mainly present in regions vulnerable to Alzheimer’s disease (Feart et al. 2016). The lutein and the zeaxanthin found also in the cerebellum, frontal cortices, occipital cortices, and pons of the brain. Their concentrations in centenarians well correlated with some cognitive functions. The higher macular pigment optical density measurements were due to the higher concentrations of the lutein and zeaxanthin in the macula. Thus, the higher yellow pigments in the macula represent a long-term consumption of these compounds and likely to derive from the whole-wheat intake while consumption of the products of the refined flour adds an only minor amount of the yellow pigments to the plasma concentrations. With the measurements of the macular optical density, we presumably evaluate the effect of the high and the long intake of the whole-­ wheat on the impaired vision and the cognition. In some studies, the plasma concentrations of the lutein and the zeaxanthin and the macular pigment optical density correlated with the cognitive performances such as verbal fluency abilities, and a higher global cognitive score, episodic memory, and verbal fluency. The associations between the macular pigment optical density and the cognitive performances consistent with previous reports of the relationships of macular pigment optical density (measured by a variety of techniques) to the cognitive function (Ajana et al. 2018). With the increasing longevity, Alzheimer’s disease and other dementia burdens, become a major issue of concern. For years, nutritionists have not considered Alzheimer and associated burdens as a nutritional concern. When initial information has begun to accumulate on the effects of the dietary items on specific cognitive burdens and the cognition characterizations, the dietary items become a main issue of concern. In the US, the prevalence of Alzheimer’s disease of ~25% for the age of >85 y has reported with the trend increase with the age and with the longevity (Koller and Bynum 2015). The xanthophyll carotenoids lutein and zeaxanthin function as both anti-oxidants and anti-inflammatory agents. While the intake of the yellow pigments may alleviate the cognitive health for the elderly, the lutein and the zeaxanthin tend to be the dominant carotenoid in the central nervous tissues when they account for the 66–77% of the total plasma carotenoids.

The Effect on the Early Development

373

The lutein and the zeaxanthin are likely to influence the inter-neuronal communication and function with the proposed mechanisms of the decrease in the oxidative stress, activation of anti-inflammatory pathways. Modulation of the functional properties of the synaptic membranes, changes in their physicochemical and structural features and enhancement of the gap junctional communication. People with the lowest quartile of the cognitive functioning had a higher probability of having the lowest first quartile of the plasma zeaxanthin and lycopene. Fruit and vegetable that well known with the high carotenoids content, their intake was associated with cognitive function. In most of the reviews described the alleviative effects of the lutein and the zeaxanthin, bread has not counted with the inducer of the cognitive functions because of the vast majority of the consumed bread produced from the refined flour with a very low content of the lutein and the zeaxanthin (Johnson 2012).

The high intake of the native “yellow-pigments” has shown to exert alleviative effects on the eye integrity with no contradictory claim. The indication of the consumption of the whole-wheat bread with a higher content of the yellow pigments might be a good suggestion for all the people with eye impairments and presumably for all the elderly population.

The Effect on the Early Development It is now widely accepted that nutrition during critical periods in early development, both pre- and postnatal, may have lifetime consequences in the determining health or onset of major diseases in adult life. The non-provitamin A carotenoids, lutein, and zeaxanthin are emerging as important modulators of infant and child visual and cognitive development, as well as critical effectors in the prevention and treatment of the morbidity associated with premature births. A still limited but growing body of evidence has supported the role of the lutein and the zeaxanthin in mammalian development, specifically in the relationship to their potential protective activity on the infant retinal and brain development and functions. The lutein levels are higher during the pre-term period (33–36 w) and declined over time suggesting that lutein has a role in the support of the development of the central nervous system, which is at its highest in terms of brain volume, weight, and structure at this gestational stage. The lutein is the main carotenoid throughout the human brain tissue not only in adult individuals but also in infants, confirming its potential role in regulating cognition. The lutein levels positively correlated with the GABA (gamma-aminobutyric acid) and aspartate neurotransmitters involved in the neuronal proliferation and maturation, the neurite outgrowth and the synapse formation. Adults in the US consume ~1.7 mg/d of lutein that presumably is insufficient to attain the health benefits

374

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that epidemiological observations have shown. Thus, the intake of the whole-wheat bread for the refined bread may fulfill a large part of the needs of the yellow pigments for pregnant the women and the infant. Reintroducing of the yellow-pigments to the depleted varieties may improve remarkably the supplementation of these ingredients (Giordano and Quadro 2018). The plausible conclusion of such long-­ run study that the neuropathological changes underlying clinically significant the cognitive impairment appear to take years, if not decades. Thus, neuroprotection may have the greatest benefit early on in the process (Study 2007). The claims for the effect of the yellow pigments to enhance early development have not gathered adequate support to recommend the intake of whole-­ wheat to enhance early development. However, such a claim of the positive effect of the yellow pigment should take into consideration.

References Abdel-Aal ESM, Young JC, Wood PJ, Rabalski I, Hucl P, Falk D, Frégeau-Reid J (2002) Einkorn: a potential candidate for developing high lutein wheat. Cereal Chem 79:455–457. https://doi. org/10.1094/CCHEM.2002.79.3.455 Abdel-Aal ESM, Akhtar H, Zaheer K, Ali R (2013) Dietary sources of lutein and zeaxanthin carotenoids and their role in eye health. Nutrients 5:1169–1185. https://doi.org/10.3390/nu5041169 Ajana S, Weber D, Helmer C, Merle BM, Stuetz W, Dartigues J-F, Rougier M-B, Korobelnik J-F, Grune T, Delcourt C, Feart C (2018) Plasma concentrations of lutein and zeaxanthin, macular pigment optical density, and their associations with cognitive performances among older adults. Invest Ophthalmol Vis Sci 59:1828–1835. https://doi.org/10.1167/iovs.17-22656 Anderson DF, Dhariwal M, Bouchet C, Keith MS (2018) Global prevalence and economic and humanistic burden of astigmatism in cataract patients: a systematic literature review. Clin Ophthalmol 12:439–452. https://www.dovepress.com/terms.php Arunkumar R, Calvo CM, Conrady CD, Bernstein PS (2018) What do we know about the macular pigment in AMD: the past, the present, and the future. Eye 32:992–1004. https://doi. org/10.1038/s41433-018-0044-0 Carneiro Â, Andrade JP (2017) Nutritional and lifestyle interventions for age-related macular degeneration: a review. Oxidative Med Cell Longev 2017:6469138–6469113. https://doi. org/10.1155/2017/6469138 Brown L, Rimm EB, Seddon JM, Giovannucci EL, Chasan-Taber L, Spiegelman D, Willett WC, Hankinson SE (1999) A prospective study of carotenoid intake and risk of cataract extraction in US men. Am J Clin Nutr 70:517–524 Clarke FR, Clarke JM, McCaig TN, Knox RE, DePauw RM (2011) Inheritance of yellow pigment concentration in seven durum wheat crosses. Can J Plant Sci 86:133–141. https://doi. org/10.4141/p05-083 Crews JE, Chou CF, Sekar S, Saaddine JB (2017) The prevalence of chronic conditions and poor health among people with and without vision impairment, aged ≥65 years, 2010–2014. Am J Ophthalmol 182:18–30. https://doi.org/10.1016/j.ajo.2017.06.038 Cui YH, Jing CX, Pan HW (2013) Association of blood antioxidants and vitamins with risk of age-­ related cataract: a meta-analysis of observational studies. Am J Clin Nutr 98:778–786. https:// doi.org/10.3945/ajcn.112.053835 Delcourt C, Carrière I, Delage M, Barberger-Gateau P, Schalch W, Lacroux A, Fourrey S, Covacho MJ, Canet C, Paillard P, Ponton-Sanchez A, Defay R, Colvez A, Papoz L, Balme-Blanchard

References

375

C, Balmelle L, Chinaud D, Costeau J, Diaz JL, Dossa C, Gallinaro C, Malan P, Robert F, Arnaud B, Cristol JP, Vernet MH, Fouret G, Michel F, Leger C, Descomps B, Mathieu-Daudé P, Mathieu-Daudé JC, Tessier F, Birlouez-Aragon I (2006) Plasma lutein and zeaxanthin and other carotenoids as modifiable risk factors for age-related maculopathy and cataract: the POLA study. Investig Ophthalmol Vis Sci 47:2329–2335. https://doi.org/10.1167/iovs.05-1235 Dror Y, Giveon SM, Stern F (2018) Chap 11: The nadir range of the U-shaped curve. In: series Rattan SIS (Ed) Healthy ageing and longevity vol 8: Malavolta M, Mocchegiani E (Eds) Trace elements and minerals in health and longevity, Springer. pp  303–325. https://doi. org/10.1007/978-3-030-03742-0/ Eggersdorfer M, Wyss A (2018) Carotenoids in human nutrition and health. Arch Biochem Biophys 652:18–26. https://doi.org/10.1016/j.abb.2018.06.001 Eisenhauer B, Natoli S, Liew G, Flood VM (2017) Lutein and zeaxanthin — food sources, bioavailability and dietary variety in age-related macular degeneration protection. Nutrients 9:120. https://doi.org/10.3390/nu9020120 Feart C, Letenneur L, Helmer C, Samieri C, Schalch W, Etheve S, Delcourt C, Dartigues JF, Barberger-Gateau P (2016) Plasma carotenoids are inversely associated with dementia risk in an elderly French cohort. J Gerontol A Biol Sci Med Sci 71:683–688. https://doi.org/10.1093/ gerona/glv135 Fu B, Chiremba C, Pozniak C, Wang K, Nam S (2017) Total phenolic and yellow pigment contents and antioxidant activities of durum wheat milling fractions. Antioxidants 6:78. https://doi. org/10.3390/antiox6040078 Giordano E, Quadro L (2018) Lutein, zeaxanthin and mammalian development: metabolism, functions and implications for health. Arch Biochem Biophys 647:33–40. https://doi.org/10.1016/j. abb.2018.04.008 Glaser TS, Doss LE, Shih G, Nigam D, Sperduto RD, Ferris FL, Agrón E, Clemons TE, Chew EY (2015) The association of dietary lutein plus zeaxanthin and B vitamins with cataracts in the age-related eye disease study AREDS report no. 37. Ophthalmology 122:1471–1479. https:// doi.org/10.1016/j.ophtha.2015.04.007 Gong X, Draper C, Allison G, Marisiddaiah R, Rubin L (2017) Effects of the macular carotenoid lutein in human retinal pigment epithelial cells. Antioxidants 6:100. https://doi.org/10.3390/ antiox6040100 Graham RD, Rosser JM (2000) Carotenoids in staple foods: their potential to improve human nutrition. Food Nutr Bull 21:404–409 Jia YP, Sun L, Yu HS, Liang LP, Li W, Ding H, Song XB, Zhang LJ (2017) The pharmacological effects of lutein and zeaxanthin on visual disorders and cognition diseases. Molecules 22:610. https://doi.org/10.3390/molecules22040610 Johnson EJ (2012) A possible role for lutein and zeaxanthin in cognitive function in the elderly. Am J Clin Nutr 96:1161s–1165s. https://doi.org/10.3945/ajcn.112.034611.1 Johnson EJ (2014) Role of lutein and zeaxanthin in visual and cognitive function throughout the lifespan. Nutr Rev 72:605–612. https://doi.org/10.1111/nure.12133 Koller D, Bynum JPW (2015) Dementia in the USA: state variation in prevalence. J Public Heal (United Kingdom) 37:597–604. https://doi.org/10.1093/pubmed/fdu080 Krinsky NI, Landrum JT, Bone RA (2003) Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr 23:171–201. https://doi.org/10.1146/annurev. nutr.23.011702.073307 Leenhardt F, Lyan B, Rock E, Boussard A, Potus J, Chanliaud E, Remesy C (2006) Genetic variability of carotenoid concentration, and lipoxygenase and peroxidase activities among cultivated wheat species and bread wheat varieties. Eur J Agron 25:170–176. https://doi.org/10.1016/j. eja.2006.04.010 Lindbergh CA, Renzi-Hammond LM, Hammond BR, Terry DP, Mewborn CM, Puente AN, Miller LS (2018) Lutein and zeaxanthin influence brain function in older adults: a randomized controlled trial. J Int Neuropsychol Soc 24:1–14. https://doi.org/10.1017/S1355617717000534 Liu XH, Yu RB, Liu R, Hao ZX, Han CC, Zhu ZH, Ma L (2014) Association between lutein and zeaxanthin status and the risk of cataract: a meta-analysis. Nutrients 6:452–465. https://doi. org/10.3390/nu6010452

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Ma L, Dou HL, Wu YQ, Huang YM, Huang YB, Xu XR, Zou ZY, Lin XM (2012) Lutein and zeaxanthin intake and the risk of age-related macular degeneration: a systematic review and meta-analysis. Br J Nutr 107:350–359. https://doi.org/10.1017/S0007114511004260 Manikandan R, Thiagarajan R, Goutham G, Arumugam M, Beulaja M, Rastrelli L, Skalicka-­ Woźniak K, Habtemariam S, Orhan IE, Nabavi SF, Nabavi SM (2016) Zeaxanthin and ocular health, from bench to bedside. Fitoterapia 109:58–66. https://doi.org/10.1016/j. fitote.2015.12.009 Mares J (2016) Lutein and zeaxanthin isomers in eye health and disease. Annu Rev Nutr 36:571– 602. https://doi.org/10.1146/annurev-nutr-071715-051110 Mellado-Ortega E, Hornero-Méndez D (2015) Carotenoids in cereals: an ancient resource with present and future applications. Phytochem Rev 14:873–890. https://doi.org/10.1007/ s11101-015-9423-3 Moeller SM, Voland R, Tinker L, Blodi BA, Klein ML, Gehrs KM, Johnson MJ, Snodderly DM, Wallace RB, Chappell RJ, Parekh N, Ritenbaugh C, Mares JA (2008) Associations between age-related nuclear cataract and lutein and zeaxanthin in the diet and serum in the carotenoids in the age-related eye disease study (CAREDS), an ancillary study of the Women’s Health Initiative. Arch Ophthalmol 126:354–364 NIH-US National Eye Institute - Age-Related Eye Diseases in America, Prevalence of adult vision impairment and age-related eye diseases in America, estimated number of cases by vision problem age ≥ 40. https://nei.nih.gov/eyedata/adultvision_usa NIH-US National Eye Institute  - Cataracts Defined Tables, https://nei.nih.gov/eyedata/cataract/ tables Olmedilla B, Granado F, Blanco I, Vaquero M, Cajigal C (2001) Lutein in patients with cataracts and age-related macular degeneration: a long-term supplementation study. J Sci Food Agric 81:904–909. https://doi.org/10.1002/jsfa.905 Ravel C, Dardevet M, Leenhardt F, Bordes J, Joseph JL, Perretant MR, Exbrayat F, Poncet C, Balfourier F, Chanliaud E, Charmet G (2013) Improving the yellow pigment content of bread wheat flour by selecting the three homoeologous copies of Psy1. Mol Breed 31:87–99. https:// doi.org/10.1007/s11032-012-9772-1 Rodriguez-Concepcion M, Avalos J, Bonet ML, Boronat A, Gomez-Gomez L, Hornero-Mendez D, Limon MC, Meléndez-Martínez AJ, Olmedilla-Alonso B, Palou A, Ribot J, Rodrigo MJ, Zacarias L, Zhu C (2018) A global perspective on carotenoids: metabolism, biotechnology, and benefits for nutrition and health. Prog Lipid Res 70:62–93. https://doi.org/10.1016/j. plipres.2018.04.004 Schulthess A, Schwember AR (2013) Improving durum wheat (Triticum turgidum L. var durum) grain yellow pigment content through plant breeding. Cienc Investig Agrar 40:475–490 Shewry PR, Hey S (2015) Do “ancient” wheat species differ from modern bread wheat in their contents of bioactive components? J Cereal Sci 65:236–243. https://doi.org/10.1016/j. jcs.2015.07.014 Song P, Wang H, Theodoratou E, Chan KY, Rudan I (2018) The national and subnational prevalence of cataract and cataract blindness in China: a systematic review and meta-analysis. J Glob Health 8:010804. https://doi.org/10.7189/jogh.08.010804 Study H (2007) Antioxidants and prevention of cognitive decline. Arch Intern Med 167:2167– 2168. https://doi.org/10.1002/14651858.CD002854.10 Wu J, Cho E, Willett WC, Sastry SM, Schaumberg DA (2015) Intakes of lutein, zeaxanthin, and other carotenoids and age-related macular degeneration during 2 decades of prospective follow­up. JAMA Ophthalmol 133:1415–1424. https://doi.org/10.1001/jamaophthalmol.2015.3590 Zhu X, Zhang S, Chang R, Lu Y (2017) New cataract markers: mechanisms of disease. Clin Chim Acta 472:41–45. https://doi.org/10.1016/j.cca.2017.07.010

Chapter 19

The Whole-Wheat Effect on Cellular Activities That Support Aging

The conclusions that we made according to the wide-scaled epidemiological studies (Table 15.1), should support the notion of the advantage intake of the whole-wheat bread for the refined flour products. Many explanations have counted for the advantage of the whole-wheat bread. Any further evidence might probably advance somehow the gigantic mountain of the refined-flour consumer towards a better sensible nutrition. We present here three most substantial cellular activities that presumably, affected, enhanced and controlled by the adequate supply of the anti-oxidants and other whole-wheat ingredients. The activity of the telomere might be only a noteworthy identifier of the advance in the cellular aging. Apoptosis and autophagy activities have a particular role in aging acceleration. Because of the apoptosis almost does not act in the neural cells, the effect of the autophagy is most crucial in the nerve cells.

 he Effect of Dietary Fiber and the Anti-oxidant Intake T on the Moderation of the Telomere Attrition and Aging The heterogeneous mixture of the anti-oxidants in the whole-wheat bread supplies >half of the total intake of the anti-oxidants in the regular diet. Such a supplementation suggests a possible and fascinating role in the moderation of the aging process. Even the relationship between the whole-bread intake and the aging processes presumably have not presented, the evidence for the indirect relationship might be most interesting and important. As mentioned above, the intake of the whole-wheat at the ~30% of the total energy of our menu doubles the dietary fiber intake and concomitantly doubles the total anti-oxidant capacity (Table 10.1) beside the effect on vitamins, minerals, methyl donors, yellow pigments, and other anti-malignant

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_19

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compounds. The dietary fiber and the anti-oxidants tightly connected in the plants and no distinction can be made between the effect of these two native ingredients. Telomere biology is a highly evolutionarily conserved system that plays a central role in maintaining the integrity of the genome and the cell (Entringer et al. 2018). The telomere comprises repeated sequences of noncoding DNA in the association with the protein complex. The telomere protects the chromosome ends from the reactive oxygen species (ROS) and the other free radicals. The rate of the telomere attrition implicated in the cellular aging, shorten with age and associated with various age-related diseases. The rate of the telomere attrition might use as a most noteworthy identifier of the general rate of the cellular aging. The telomere attrition and dysfunction associated with many age-related diseases, including cancer, type 2 diabetes mellitus, cardiovascular disease, osteoarthritis, dementia, and immunosenescence, where the rate of shortening seems to accelerate, playing a synergistic role with the aging (Olsson et al. 2018; Lorenzi et al. 2018). In a rodent model, the decreased anti-oxidant defense mechanisms and accelerated telomere shortening across different tissues in the offspring have reported (Entringer et  al. 2018). Among the primary hallmarks of the aging that have described, the telomere length has earned much attention in the past 2 decades. The naturally occurring chemicals of the polyphenols have shown positive effects on the telomere length and the organismal aging (Vidacek et al. 2017). The effect of the dietary intake on the telomere leukocyte evaluated in the subjects of 20–85 y, n  =  5674, both genders, at an intake range of 2.4 (10th%) -12 (90th%) g fiber/Mcal evaluated in the US NHANES (1999–2002). The total fiber intake linearly related to the leukocyte telomere length in a large sample of women and men representing the US adult population. Additionally, with the quartiles of the fiber intake, the fourth quartile had longer telomeres than the first one, suggesting the less biologic aging. According to the attrition calculation, a difference of 4.8–6.0 years in cell aging found between those quartiles (first vs fourth) of the fiber intake calculated (thus, a moderation in the aging advance with the higher intake of the dietary fiber). This evidence highlights the risk of accelerated aging among US women and men with inadequate dietary fiber (Tucker 2018). Presumably, the anti-­ oxidant capacity that normally bound to the dietary fiber, comprises the most critical activity for the moderation of the telomere attrition. The telomere attrition has shown as a reliable measure for the evaluation of the rate of the cellular aging. Unfortunately, the total anti-oxidant capacity or specific anti-oxidant compound such as ferulic acid has not evaluated routinely and not presented in the food tables. Eventually, these ingredients are rarely presented. While other ingredients have evaluated for the correlation with the telomere attrition no calculation was conducted for the anti-oxidant capacity. With the doubling of the dietary fiber and total anti-­oxidant intakes with the intake the whole-wheat at the scale of >30% of the total energy, evaluation of the whole-wheat effect on the telomere attrition is most important. Because of the major anti-oxidant-capacity tightly bound the wheat bran fraction and the dietary fiber, we suggest that the anti-oxidant capacity of the whole-bread act vigorously with the telomere vicinity and the other cellular sites to moderate the

A Possible Effect of the Whole-Bread Ingredients on the Dynamics of the Autophagy…

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deleterious effect of the reactive oxygen species that generally considered like the main attrition factor (Rafie et al. 2017). The specific alleviative effect of the whole-grain intake on the moderation of the telomere attrition has shown long ago (Vivo et  al. 2010). Because of the whole-­cereal when consumed as the sole bread source, comprises the dominant food item such information should be a cornerstone in any nutritional evaluation when the consideration dietary fiber or the total anti-oxidant capacity. However, in the discussion of the telomere attrition whole-bread, like it, was not evaluated (Rafie et al. 2017). Whether the evidence of the whole-bread effect on the moderation of the telomere attrition would well be accepted, only this evidence alone may justify the authoritative recommendation of the intake of the whole-wheat bread for the refined products.

 Possible Effect of the Whole-Bread Ingredients A on the Dynamics of the Autophagy and Apoptosis The autophagy and the apoptosis are two main fundamental processes in the biology that highly conserved and tightly connected with the main pivotal cellular survival, organization, and aging routes. Even so, the nutritional role in these self-destructive and the organizing processes of the control devices mostly ignored. The autophagy and the apoptosis often operated within the same cell, mostly in a sequence in which the autophagy precedes the apoptosis (Mariño et  al. 2014). The proteins and the organelles are continuously synthesized and degraded in the cells so that the obsolete and the dysfunctional elements replaced with new ones. The proper turnover rates of the proteins and the organelles critical for the homeostasis survival, and the adaptation to stress. The high contribution of the whole-wheat bread in the total menu with the dietary fiber and the total anti-oxidant capacity present in the whole-­ bread as a food item with the high capacity to induce the critical cellular activities that highly affected by the menu score. While the apoptosis almost not acting in the neural tissues, presumably the neural autophagy highly dependent on the optimal activity on the accurate concentrations of all the micronutrients. The autophagy is an evolutionarily conserved mechanism of the degradation of the cytoplasmic elements and plays a pivotal role in the quality control of the proteins and the organelles. The autophagy also regulates the secretion and intracellular trafficking. Among these, the mitophagy is a specialized form of the autophagy devoted to the removal and the digestion of the damaged mitochondria. During the past decade, the autophagy has also emerged as a major regulator of the cardiac homeostasis and function. The autophagy maintains the cardiac structure and function at baseline by eliminating the misfolded proteins and the damaged organelles (Sciarretta et al. 2018). The role of the autophagy in the infectious diseases is apparent at the level of the microbial

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handling by the innate immune system, as well as the antigen processing and the presentation of a wide variety of the microorganisms ranging from viruses to bacteria, fungi, and protozoa. The anti-oxidant compounds pertain to affect radical scavenging, inhibition of the lipid peroxidation and protection against the LDL oxidation. The ability of the dietary polyphenols to act as the anti-oxidants/pro-oxidants are dependent on the concentration, the structure, and the substrate to be protected (Maurya and Devasagayam 2010). The autophagy contributes to the maintenance of the cell homeostasis by eliminating damaged organelles and the misfolded proteins, aggregated proteins, modified proteins, and the polymeric lipids. The autophagy induced by various stresses, including nutrient starvation and the reactive oxygen species (Bian et  al. 2012). Various plant metabolites, like the polyphenols regulating the autophagy. Many of the 4000 flavonoids identified in the plants have the quality of the anti-oxidants, which enhance the health quality in humans. The polyphenol compounds, including the flavonoids, can inhibit the intracellular aggregation and thus ameliorate the cognitive defects. Thus, the pro-autophagy diet, which is rich in fruits and vegetables as well as the whole-wheat, might be connected to autophagy induction. An optimal rate of the autophagy degradation needs an adequate concentration of the micronutrients and also anti-oxidants of all groups (Dror, Stern and Gomori 2015). However, even we do not know the required concentrations of the micronutrients to maximize the autophagy and the apoptosis we presume that the nadir range assures the optimal activity. Also, the nadir range required for the anti-oxidant ingredients. The ferulic acid is the predominant anti-oxidant in the kernel wheat and comprises >25% of the total phenolic compounds. Besides the effect of ferulic acid as an anti-oxidant, it has specific activities on the enhancement and the control of cellular autophagy and apoptosis. Few pieces of evidence show the effect of ferulic acid on the retardation of vascular dementia. The ferulic acid protected the brain microvascular endothelial cells through a mechanism of the mitochondrial autophagy or the mitophagy. The ferulic acid attenuated brain microvascular endothelial cells damaged by the oxygen-glucose deprivation. Oxygen-glucose deprivation-­ induced the mitochondrial fission was crucial for the occurrence of the ferulic acid promoted autophagy (Chen et al. 2017). Some natural polyphenolic compounds, including curcumin, genistein, quercetin, rottlerin, and resveratrol could induce the autophagic programmed cell death through various approaches. The phytochemicals participate in the finest mechanisms of the modulation of the relationship autophagy (mitophagy) and apoptosis, via the mitochondria-endothelial-reticulum and proteasome, these compounds are mostly known as disturbing the cell cycle, triggering the apoptosis, preventing tumor cell metastasis, potentiating the functions of the chemotherapeutic agents, inducing the autophagy, and the activating antitumor effects in vivo, thus suggesting flavonoids as promising anti-cancer agents (Bjørklund et al. 2017). The intensity of the autophagy depends on the availability and the strength of the inducers which include the internal factors (deficit of the nutrients, presence of the damaged organelles, denatured proteins and their aggregates, the oxidative and toxic stress) or the external factors such as bacteria or viruses, interferon γ, and

The Effect on Cognition

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vitamin D. The induction of the autophagy occurs within 1 h following the exposure to the strong stimuli and the process slows after 24 h. The mechanisms of the indirect protective effect of the phenols identified in particular their ability to activate the system of the anti-oxidant responsive element, and induce the autophagy. Such effect of phenolic compounds is important for the protection against the oxidative and the carbonyl stress, motivating us to analyze possible mechanisms of the effect of the natural phenols on the signaling system and the autophagy. More than 30 proteins involved in the activation of the autophagy and it is the overall picture is extremely complicated and not fully understood mechanisms. Studies of the Saccharomyces cerevisiae cells revealed 35 genes required for the autophagy, which combined into a group referred to the autophagy-­ related genes. Many analogs of the autophagy yeast proteins found in the mammals (Zenkov et al. 2016). By using a conventional green fluorescent protein-­microtubule-­ associated protein light chain 3 (GFP-LC3) evaluate autophagy flux, ferulic acid showed to cause a significant increase in the GFP-LC3 dots under serum-rich conditions in the HeLa cells. The enhancement of the autophagic flux by the ferulic acid was remarkable. Furthermore, the ferulic acid enhanced the autophagic degradation of the 14C-leucine-labeled long-lived proteins of the cultured mouse hepatocytes under the nutrient-rich conditions. Autophagy significantly contributes to the cellular quality control by removing the unfolded and denatured proteins. The results indicate that in addition to the known effects of the ferulic acid against the oxidative stress, the stimulatory effect on the autophagy by the ferulic acid may have additional functional implications in the cell-protective roles. The autophagic effect supports the concept that a stimulatory effect on autophagy is a general characteristic of the polyphenols (Bian et al. 2012).

The Effect on Cognition Synapses are dynamic structures that allow the neurons to communicate via the release of the neurotransmitters, in effect, enabling them to form the neural networks, which, in turn, provide the basis for the brain function as such. Certain instructive patterns of such neuronal activity trigger a spectrum of the changes tuning synapse function and structure. The cognitive performance in the aging sensitive to already subtle deficits of the neuronal performance. The aging accompanied by a cognitive decline in a major segment of the population, and, given the strong increase in the life expectancy, the age-induced memory impairment has emerged as one of the top public health threats over the last few decades. Accrual of the deficits in the autophagy clearance might be a crucial driver of the neurodegeneration. Restoring the synaptic and the neuronal activities are a promising strategy to combat the aging and the neurodegeneration-associated pathology (Liang and Sigrist 2018).

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The crucial role of the micronutrients in the preservation of the brain cell integrity by the retaining of the normal autophagy and in particular in the brain cells that are sensitive to the normal activity of the autophagy. Even autophagy and apoptosis are the most ancient processes in the preservation of the integrity of the multicellular animals, its appearance in the scientific documentation has only recently got attention. Within the last decade, the term autophagy in the scientific literature has increased by about 20 fold with an annual increase of >10%. The term apoptosis has a wider circle of interest but for both terms, the effect of dietary ingredients on these processes has accumulated only on a limited scope. We have collected only a limited piece of information and presented here some of the data that might tightly related to the alleviative effect of the whole-wheat intake on the decrease in the relative risks of morbidity and mortality. Autophagy and apoptosis are two major biological functions of the renewal organismal structure and enhance the robustness of the physiological activity. They controlled by many genes while the detailed control machinery is presumably at the beginning of a thorough description. Dietary polyphenol and other antioxidant compounds have shown to affect the activities of these two self-eating control mechanisms. Because the polyphenols and the other antioxidant compounds derived from the dietary whole-wheat comprise more than half of the total dietary polyphenols, we presume that the alleviative effect of the whole-wheat intake partially derived from the activity of the antioxidants on the autophagy and the apoptosis. The antioxidant compounds of the whole-wheat are mostly bound compounds and thus distinct from those of the fruits and vegetablesa as those are mostly free compounds. Bound compounds might have a higher efficiency than free ones. We have presented here the primary data for the effect of the whole-wheat intake on autophagy and apoptosis and the possible outcomes on cellular integrity. This primary data does not have the validity as to the effect of whole-­ wheat intake on a long list of morbidity and mortality cases that supported the wide-scaled epidemiological studies (Table 15.1). The data for autophagy cannot support consensual nutritional recommendations for a higher intake of the whole-wheat bread for the prevention or even correction brain lesions related to vascular dementia, Alzheimer’s disease, or Parkinson’s diseases. However, because of the data for the autophagy are highly related to the epidemiological data (Table 15.1) that supported on observations collected from >37M subjects, we may recommend whole-­ wheat intake as a good nutritional precautionary mean to ensure a higher health status and the moderation of proteinopathies and on the cellular degenerative agents. However, whether anyone might consider whole-wheat intake as an immediate remedy, correction of such morbidities are far beyond the capacity of any nutritional ingredient.

References

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No direct evidence for the effect of the whole-wheat on the cognitive ability have presented yet but some pieces of information support the idea that the whole-wheat intake is most crucial for the innovative human cognition. The total dietary fiber was positively associated with the accuracy of an attentional inhibition task among prepubertal children. Higher diet quality, specifically with a higher fiber intake, may be important for prepubertal upregulation of the cognitive control when faced with higher cognitive demands in childhood. The dietary fiber may influence the cognitive and brain health through the immunomodulation and/or the gut- microbiota-brain system. The bacterial fermentation end-products such as the SCFA shown to downregulate the pro-inflammatory cytokines ex vivo and to increase the brain-derived neurotrophic factor transcripts in the frontal cortex. In addition to such as SCFA production, soluble fibers-acting as the prebiotics, have the potential to proliferate the health-promoting bacteria (Khan et al. 2015). A higher dietary intake of the lignans associated with a better cognitive function in postmenopausal women (Franco et al. 2018). The intake of the bread and the cereals were inversely associated (protective effect) with cognitive impairment. People who ate bread or cereals at least weekly were more than 60% likely to have cognitive impairment than those who did not (Rahman et al. 2007). A higher dietary intake of the lignans associated with a better cognitive function in postmenopausal women (Franco et al. 2018). The intake of the bread and the cereals were inversely associated (protective effect) with cognitive impairment. People who ate bread or cereals at least weekly were more than 60% likely to have cognitive impairment than those who did not (Rahman et al. 2007). ROS and NOS are families of the highly reactive species formed either enzymatically or non-enzymatically in mammalian cells. Because of the continuous high intensity of the energy prduction in the brain, the brain prone to a high risk of the reactive species and glutathione reductase is an important ingredient in achieving reactive oxygen species (ROS) production. The high concentrations of total urinary polyphenols, a nutritional biomarker of the polyphenol intake, were associated with the lower risk of the substantial cognitive decline in an older population studied over a 3-y period, suggesting a protective effect against the cognitive impairment (Rabassa et al. 2015).

References Bian Z, Furuya N, Zheng DM, Trejo JAO, Tada N, Ezaki J, Ueno T (2012) Ferulic acid induces mammalian target of rapamycin inactivation in cultured mammalian cells. Biol Pharm Bull 36:120–124. https://doi.org/10.1248/bpb.b12-00695 Bjørklund G, Dadar M, Chirumbolo S, Lysiuk R (2017) Flavonoids as detoxifying and pro-­ survival agents: what’s new? Food Chem Toxicol 110:240–250. https://doi.org/10.1016/j. fct.2017.10.039

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Chen JL, Duan WJ, Luo S, Li S, Ma XH, Hou BN, Cheng SY, Fang SH, Wang Q, Huang SQ, Chen YB (2017) Ferulic acid attenuates brain microvascular endothelial cells damage caused by oxygen-glucose deprivation via punctate-mitochondria-dependent mitophagy. Brain Res 1666:17–26. https://doi.org/10.1016/j.brainres.2017.04.006 Dror Y, Stern F, Gomori MJ (2015) Vitamins in the prevention or delay of cognitive disability of aging. Curr Aging Sci 7:187–213. https://doi.org/10.2174/1874609808666150201214955 Entringer S, Punder KD, Buss C, Wadhwa PD (2018) The fetal programming of telomere biology hypothesis: an update. Philos Trans R Soc B Biol Sci 303:20170151. https://doi.org/10.1098/ rstb.2017.0151 Franco OH, Burger H, Lebrun CEI, Peeters PHM, Lamberts SWJ, Grobbee DE, Schouw YTVD (2018) Higher dietary intake of lignans is associated with better cognitive performance in postmenopausal women. J Nutr 135:1190–1195. https://doi.org/10.1093/jn/135.5.1190 Khan NA, Raine LB, Drollette ES, Scudder MR, Kramer AF, Hillman CH (2015) Dietary fiber is positively associated with cognitive control among prepubertal children. J Nutr 145:143–149. https://doi.org/10.3945/jn.114.198457 Liang YT, Sigrist S (2018) Autophagy and proteostasis in the control of synapse aging and disease. Curr Opin Neurobiol 48:113–121. https://doi.org/10.1016/j.conb.2017.12.006 Lorenzi M, Bonassi S, Lorenzi T, Giovannini S, Bernabei R, Onder G (2018) A review of telomere length in sarcopenia and frailty. Biogerontology 19:209–221. https://doi.org/10.1007/ s10522-018-9749-5 Mariño G, Niso-Santano M, Baehrecke EH, Kroemer G (2014) Self-consumption: the interplay of autophagy and apoptosis. Nat Rev Mol Cell Biol 15:81–94. https://doi.org/10.1038/nrm3735 Maurya DK, Devasagayam TPA (2010) Antioxidant and prooxidant nature of hydroxycinnamic acid derivatives ferulic and caffeic acids. Food Chem Toxicol 48:3369–3373. https://doi. org/10.1016/j.fct.2010.09.006 Olsson M, Wapstra E, Friesen CR (2018) Evolutionary ecology of telomeres: a review. Ann N Y Acad Sci 1422:5–28. https://doi.org/10.1111/nyas.13443 Rabassa M, Cherubini A, Zamora-Ros R, Urpi-Sarda M, Bandinelli S, Ferrucci L, Andres-Lacueva C (2015) Low levels of a urinary biomarker of dietary polyphenol are associated with substantial cognitive decline over a 3-year period in older adults: the invecchiare in chianti study. J Am Geriatr Soc 63:938–946. https://doi.org/10.1111/jgs.13379 Rafie N, Hamedani SG, Barak F, Safavi SM, Miraghajani M (2017) Dietary patterns, food groups and telomere length: a systematic review of current studies. Eur J Clin Nutr 71:151–158. https://doi.org/10.1038/ejcn.2016.149 Rahman A, Baker PS, Allman RM, Zamrini E (2007) Dietary factors and cognitive impairment in community-dwelling elderly. J Nutr Health Aging 11:49–54 Sciarretta S, Maejima Y, Zablocki D, Sadoshima (2018) The role of autophagy in the heart. Annu Rev Physiol 80:1–26. https://doi.org/10.1146/annurev-physiol-021317-121427 Tucker LA (2018) Dietary fiber and telomere length in 5674 U.S. adults: an NHANES study of biological aging. Nutrients 10:400. https://doi.org/10.3390/nu10040400 Vidacek NŠ, Nanic L, Ravlic S, Sopta M, Geric M, Gajski G, Garaj-Vrhovac V, Rubelj I (2017) Telomeres, nutrition, and longevity: can we really navigate our aging? J Gerontol A Biol Sci Med Sci 73:39–47. https://doi.org/10.1093/gerona/glx082 Vivo ID, Liu Y, Han J, Prescott J, Hunter DJ, Rimm EB (2010) Associations between diet, lifestyle factors, and telomere length in women. Am J Clin Nutr 91:1273–1280. https://doi.org/10.3945/ ajcn.2009.28947 Zenkov NK, Chechushkov AV, Kozhin PM, Kandalintseva NV, Martinovich GG, Menshchikova EB (2016) Plant phenols and autophagy. Biochemist 81:297–314. https://doi.org/10.1134/ s000629791

Chapter 20

The Effect of the Starchy Staple Foods on the Wheat Consumption

Potato Versus Wheat Consumption Within Western societies, the potato is the most frequently consumed as the ­non-­cereal staple food with high-energy content. The high exchangeable rate of the wheat/potato, strongly affect the wheat intake and therefore should discuss concomitantly with the wheat nutritional qualities and consumption. In some of the countries, in particular, in Eastern Europe, the potato consist of a considerable part of the menu and any marked change in its consumption might strongly affect the economy of the local agriculture. The processing type for potato consumption has a critical role in the nutritional quality of the potato. In many countries, a high part of the potato processed at high and very high temperatures. Such processing resulted in the considerable production of the harmful Maillard compounds including the acrylamide known as malignant compounds. Regular bread baking also produced acrylamide but with much lower concentration. It still a most important and open question, does the replacement of whole-­ wheat bread for fried potato intake has an advantage in human welfare.

The Anti-oxidant Content of the Kernel Corn (Maize) Within the last decades, the corn (maize) grain has become the main grain and fodder crop for human and his livestock worldwide. The wheat and the maize both classified as the clad of Poaceae while the maize classifies as the genus Zea and the wheat species as the genus Triticum. The wheat kernels consumed mainly for human food while the corn grains for the livestock feeding. The corn kernels used also for some industrial usages at a considerable extent. Additionally, both crops the wheat and in particular the corn cultivated and harvested as fodder feeding for a ruminant. © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_20

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The term “corn” has various meanings depending on the different geographical regions. It stands for any local grains that are safe to eat and harvested in large areas. For the British people, corn is the chief grain that available as a food crop; so they interpreted the corn as wheat. When the English and the German speakers entered the New World, they attributed the term corn to the local grain namely “Zea mays”. At the same time, they distinguished Zea mays as Indian corn, to keep the word “corn” separate to apply it to the grains in total. In the US with the highest production, the term “corn” dominates. In scientific literature, the terms “corn” counted evenly as the term “maize” (Web of Sciences). The US and China shares ~70% of world production. In many countries in Africa and South and Central America, the daily intake exceeds 100 g/capita. In some of the African countries, and in Mexico, the daily intake exceeds 250 g/capita, and even in the European countries, the maize consumed as a staple and compete with the wheat intake (Ranum et al. 2014). The corn contains ~9% dietary fiber per dry matter that somewhat lower than that of the wheat (USDA food Tables (2019). In some countries in Africa and Central and South America, corn consumed as the main staple food. Some nutritional issues presented for the wheat as the staple food might be presented for the corn but with other aspects and elucidations. The lower content of the essential amino acids lysine and tryptophan generally considered as the main drawback of human nutrition. However, many corn varieties containing very high concentrations of polyphenols and the yellow pigments. With a balanced diet containing adequate protein content, corn intake might have a nutritional advantage. The corn contains a high content of anti-oxidants and bound phenolics. In some of the varieties, the content is higher than in the wheat kernel (Butts-Wilmsmeyer et al. 2017; Hung 2016) with the high variability of the anti-oxidant content between the cultivars (Tian et al. 2013; Sarepou et al. 2015; Lago et al. 2014). The red and the blue corn contain high phenolic compounds as compared to the light-colored corn genotype with also a high variability in the anti-oxidants content (Žilić et al. 2012). The lutein and the zeaxanthin content of the yellow corn have much higher content than in other grains and more than in most of the edible vegetables. The high variability in the phenolics content leaves a wide room for the breeder to supply the consumer corn varieties with superior nutritional quality in the highest anti-oxidant capacity. Such quality is the most important nutritional quality in low-income countries where the corn is the main staple food. However, in the developed countries >85% of the corn used for animal feed (Plate and Gallaher 2005).

References

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References Butts-Wilmsmeyer CJ, Mumm RH, Bohn MO (2017) Concentration of beneficial phytochemicals in harvested grain of U.S. yellow dent maize (Zea mays L.) germplasm. J Agric Food Chem 65:8311–8318. https://doi.org/10.1021/acs.jafc.7b02034 Hung PV (2016) Phenolic compounds of cereals and their antioxidant capacity. Crit Rev Food Sci Nutr 56:25–35. https://doi.org/10.1080/10408398.2012.708909 Lago C, Cassani E, Zanzi C, Landoni M, Trovato R, Pilu R (2014) Development and study of a maize cultivar rich in anthocyanins: Coloured polenta, a new functional food. Plant Breed 133:210–217. https://doi.org/10.1111/pbr.12153 Plate AYA, Gallaher DD (2005) The potential health benefits of con components and products. Cereal Foods World 50:305–314 Ranum P, Peña-Rosas JP, Garcia-Casal MN (2014) Global maize production, utilization, and consumption. Ann N Y Acad Sci 1312:105–112. https://doi.org/10.1111/nyas.12396 Sarepoua E, Tangwongchai R, Suriharn B, Lertrat K (2015) Influence of variety and harvest maturity on phytochemical content in corn silk. Food Chem 169:424–429. https://doi.org/10.1016/j. foodchem.2014.07.136 Tian J, Chen H, Chen S, Xing L, Wang Y, Wang J (2013) Comparative studies on the constituents, antioxidant and anticancer activities of extracts from different varieties of corn silk. Food Funct 4:1526–1534. https://doi.org/10.1039/c3fo60171d USDA food tables (2019) FoodData Central USDA, http://www.ars.us da.gov/nutrientdata Web of Science: https://clarivate.com/products/web-of-science/ Žilić S, Serpen A, Akillioǧlu G, Gökmen V, Vančetović J (2012) Phenolic compounds, carotenoids, anthocyanins, and antioxidant capacity of colored maize (Zea mays L.) kernels. J Agric Food Chem 60:1224–1231. https://doi.org/10.1021/jf204367z

Chapter 21

The Ready-to-Eat Cereals (RTEC)

The additives for the ready-to-eat cereals such as sodium chloride, sugar, uncontrolled amounts of vitamins and minerals and the isolated dietary fiber spoil the positive effect of the whole-grain. Even so, on the bottom line, because the products not refined the RTEC exerts a positive effect that supports the notion of the superiority of the whole-grain.

The escalating share of the ready to eat cereals (RTEC) in the menu of the leading industrial countries has changed dramatically the dynamic trend in the bakery industry. The RTEC industry characterized by high concentration, high price-cost margins, large advertising-to-sales ratios, numerous introductions of new products and a low share of the materials in the total cost (27% versus 63% for the whole-­food industry) (Nevo 2001). The RTEC defined as oligopoly market, where a large percentage of the industry dominated by a few leading firms which comprised of a handful of competitors that responsible for the bulk of industry output. These firms have the ability to set pricing and product strategy and enjoy the potential for economic profits in both the short run and the long run. The demand for cereals is inelastic, while the consumer is not likely to make large shifts in the consumption of cereals if the price changes. The ready-to-eat breakfast cereals are a popular breakfast food in 38% of the U.S. population consumed them on a given day. Manipulating the relative prices of high- and low-nutrition cereals may encourage some consumers to improve the nutritional quality of their cereal consumption (Lin et al. 2017).

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The Extent of the RTEC Consumption Within the high-income countries, the RTEC is presumably the most competitive product of the whole-wheat bread and concomitantly completes the nutritional needs supplied by the whole-wheat. Without the added sugar, salt and the excessive vitamins and minerals, the RTEC, might be similar in their nutritional quality as the whole-bread. The RTEC commonly contain all the fraction of the wheat bran with the high expansion rate in the consumption. The increase in the consumption of the RTEC replaces that of the refined bakery products. As a sophisticated industrial product, the RTEC contain added ingredients such as sugar, salt, vitamins, and minerals. The amounts of these materials depend on the consumer response and highly affected by the massive advertising but limited somehow by the loose public regulations. Many products processed by extrusion that might destruct some of the wheat anti-oxidant capacity. However, presently such an important quality does not analyze and does not evaluate The brand number of breakfast cereals in the US has grown continuously with ~5000 items at the present. The industry of the RTEC is a classic example of an industry with nearly collusive pricing behavior and intense non-price competition. Competition by means of advertising was a characteristic of the industry since its early days. Today, advertising-­to-sales ratios are about 13%, compared to 2–4% in other food industries. For the well-established cereal brands, the advertising-to-sales ratio is roughly 18%. Contrary to common belief, RTEC is quite complicated to produce. Although the fundamentals of the production are simple and well known, these processes, especially extrusion, require production experience (Nevo 2001). The RTEC breakfast cereals are a popular breakfast food while 38% of the U.S. population consumed them on a given day (Lin et al. 2017). The complication of the production of the RTEC and the necessity to invest in the huge plants have centralized extremely this industry. In the US, two vendors produce ~63% of the market and an additional one 10% of the products. While the vast majority of the bakery industry use wheat, the RTEC comprises four main species namely corn, wheat, oats, and rice. Such variability might have some nutritional advantage for the products. That extreme centralization enabled the industry to divert a considerable part of the revenue for advertisement and development. Thank for such an investment in advertisement and new products the industry has succeeded to pursue the shopper to consume a considerable part of his energy intake from whole-grain kernels with high acceptability even the price for the consumer is much higher than that for the whole-wheat bread. On the contrary, the bakery industry has not succeeded to produce and to market a considerable part of the bread as a whole-wheat product. On the bottom line, the nutritious effect of the high intake of the RTEC consumed for the refined bread products, similar to that of the whole-wheat intake consumed for refined wheat products.

The Effect of the Consumption of the RTEC on the Morbidity and the Mortality

391

 he Effect of the Consumption of the RTEC on the Morbidity T and the Mortality Because of the intake of the wheat products mainly derived from the refined wheat products the increase in the RTEC intake stands for the decrease in the refined products. Thus, the high intake of the RTEC may be compared to the low intake (Table 21.1) for the effect on the mortality and on the incidence of overweight. The data for RTEC (Table  21.1) based on ~418  k subjects, well support the general notion of the marked advantage of whole-grain consumption. A median of 0.87 of the relative risk for mortality caused by six cancer definitions (all-cause, coronary vascular diseases, diabetes type 2, cancer, respiratory diseases, and infectious diseases). The global effect of the high intake on the median incidence of overweight is 0.68 with high variability and with only four studies. The data for the mortality incidence does not cover the information collected in children and the products with the high sugar RTEC that highly predominate in the cereals for children. Table 21.1  The effect of the high intake of the RTEC on the relative risk (RR) of the morbidity and the mortality, and the RR for overweight incidence Rangea Subjects Period Site K Incidence of all-cause mortality Xu et al. (2016) US 1995–1997 397 Incidence of CVD mortality Xu et al. (2016) US 1995–1997 397 Incidence of diabetes mortality Xu et al. (2016) US 1995–1997 397 Incidence of cancer mortality Xu et al. (2016) US 1995–1997 397 Incidence of respiratory diseases mortality Xu et al. (2016) US 1995–1997 397 The incidence of infectious diseases mortality Xu et al. (2016) US 1995–1997 397 The global average relative risk for mortality cases 0.86 Incidence of overweight Albertson et al. US-MN 1998–1999 0.6 (2003) Albertson et al. US-MN 2006–2008 1.81 (2003) Valenzuela et al. Santiago, 1984–1997 1.5 (2015) Chile Bazzano et al. US 1984–1997 18 (2005) Median of relative risk 0.68 a

Ready-to-eat cereals (RTEC), g or serving/d

Age/gender Unit Low

High RR

62

g/d

0

22

0.85

62

g/d

0

22

0.76

62

g/d

0

22

0.70

62

g/d

0

22

0.90

62

g/d

0

22

0.91

62 g/d 0 22 Global median relative risks for mortality 0.87

0.97

4–12

Serv 0.07

0.86 0.45

>55

Serv 0.07

0.86 0.91

1.5

g/d

70

0.39

18

Serv 0.14

1

0.91

0

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21  The Ready-to-Eat Cereals (RTEC)

We have located some other studies that show the advantage of the ready to eat cereal consumption. (a) A comprehensive review shows that the consumption of RTEC may have beneficial effects on hypertension and type 2 diabetes. Frequent consumption of RTEC (>5 serv/wk) as compared to no or low RTEC consumption associated with a healthier dietary pattern, concerning the intake of carbohydrates, dietary fiber, fat, and micronutrients. The impact of frequent RTEC consumption on the inadequacy of the micronutrient intake is the highest for vitamin A, calcium, folate, vitamin B6, magnesium and zinc (Priebe and McMonagle 2016) (b) In a comprehensive review of 51 studies, the following details have gathered for the beneficial effect of the high intake of the RTEC. The consumers with the high intake had lower BMI unit and with a lower relative risk of 0.88 to become overweight. (c) The incidence of RR for type 2 diabetes comparing the highest vs. the lowest consumption of whole-grain breakfast cereals was 0.72. (d) Consumption of the breakfast cereals associated with a better cardiovascular lipid profile, specifically lowers the total and the LDL cholesterol, although there seems to be no effect on the HDL cholesterol. (e) A relative risk of 0.81 found for hypertension incidence with a daily breakfast cereal consumption and a stronger relation with whole-grain than with refined-­ grain cereals. (f) In the data analyzed from the National Health and Examination Survey (NHANES) study, the consumption of the cereal breakfast was associated with a relative risk of 0.64 for the incidence of hypertension. (g) Breakfast cereals provide 8–12% of the dietary fiber in adult diets in the US, the UK, and Australia and therefore have an important role in supporting the healthy laxation. (h) Adding dietary fiber to the breakfast cereals in institutional settings such as nursing homes can alleviate problems of constipation. (i) In a 21-y follow-up of 27 K adults in the Seventh-day Adventist study calculated the OR for the all-cause mortality was 0.84 when the comparison made for the most frequent vs the least-frequent breakfast cereal consumption. (j) In the US Physicians’ Health Study, within the follow-up of 5.5 y, total mortality of 0.83 OR was inversely associated with the whole-grain breakfast cereal intake (Williams 2014). (k) In a survey of 12 studies published (1998–2009), the consumption of a whole-­ grain ready-to-eat oat cereal as part of a dietary program for weight loss had favorable effects on fasting lipid levels and waist circumference in children and adolescents aged 4–17 (Kosti et al. 2010). (l) In a survey of 32 studies (published 1981–2014) the frequent consumption of RTEC as compared to no or low consumption associated with a healthier dietary pattern, concerning intake of carbohydrates, dietary fiber, and micronutrients.

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(m) A study conducted in Minnesota (1987–1996), in 660 children, 8–17 y, show that consistent RTEC consumption contributes to a healthful dietary pattern and nutrient intake that is favorably associated with the risk factors of the coronary vascular diseases such as the lipid levels and BMI, particularly among boys. The higher consumption contains a higher dietary fiber intake but also higher sucrose intake (Albertson et al. 2009). The RTEC consumption has highly expanded in the market-places and in particular in the advanced industrialized countries. Consumption of the RTEC generally replaces the intake of refined wheat products. The intake of the RTEC might have a similar alleviative impact on the health status as for the whole-wheat bread whether not heavily spoiled by foreign and destructive additives and in particular sugar, salt, and saturated fat. Except for the whole-­ wheat, the RTEC contains other edible cereals such as corn (maize), rye, oat, rice, and barley. Some of these cereals contain higher concentrations of antioxidant compounds (Table 9.2) and dietary fiber than those of the whole-­ wheat. The data for the impact of the whole-wheat on the alleviative effect of the health status is much more extensive than for the other cereals. The information gathered for the RTEC limited in comparison to that collected for the whole-wheat but well support the advantage shown for the whole-wheat products.

References Albertson AM, Anderson H, Crockett SJ, Goebel MT (2003) Ready-to-eat cereal consumption: its relationship with BMI and nutrient intake of children aged 4 to 12 years. J Am Diet Assoc 103:1613–1619 Albertson AM, Affenito SG, Bauserman R, Holschuh NM, Eldridge AL, Barton BA (2009) The Relationship of Ready-to-Eat cereal consumption to nutrient intake, blood lipids, and body mass index of children as they age through adolescence. J Am Diet Assoc 109:1557–1565. https://doi.org/10.1016/j.jada.2009.06.363 Bazzano LA, Song Y, Bubes V, Good CK, Manson JAE, Liu S (2005) Dietary intake of whole-and refined grain breakfast cereals and weight gain in men. Obes Res 13:1952–1960 Kosti RI, Panagiotakos DB, Zampelas A (2010) Ready-to-eat cereals and the burden of obesity in the context of their nutritional contribution : are all ready-to-eat cereals equally healthy? A systematic review. Nutr Res Rev 23:314–322. https://doi.org/10.1017/S095442241000020X Lin B-H, Dong D, Carlson A, Rahkovsky I (2017) Potential dietary outcomes of changing relative prices of healthy and less healthy foods: the case of ready-to-eat breakfast cereals. Food Policy:68–77. https://doi.org/10.1016/j.foodpol.2017.01.004 Nevo A (2001) Measuring market power in the ready-to-eat cereal industry. Econometrica 69:307– 342. http://www.jstor.org/stable/2692234 Priebe MG, McMonagle JR (2016) Effects of ready-to-eat-cereals on key nutritional and health outcomes: a systematic review. PLoS One 11:e0164931. https://doi.org/10.1371/journal. pone.0164931 Valenzuela OC, Zúniga JL, Landa ADD, Thielecke F, Mondragón MM, Narkunska JR, Munoz SC (2015) Consumption of ready-to-eat cereal is inversely associated with body mass index

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in 6-13 years old Chilean schoolchildren. Nutr Hosp 32:2301–2308. https://doi.org/10.3305/ nh.2015.32.5.9604 Williams PG (2014) The benefits of breakfast cereal consumption: a systematic review of the evidence base. Adv Nutr 5:636S–673S. https://doi.org/10.3945/an.114.006247.animal Xu M, Huang T, Lee LW, Qi L, Cho S (2016) Ready-to-eat cereal consumption with total and cause-­ specific mortality: prospective analysis of 367,442 individuals. J Am Coll Nutr 35:217–223

Chapter 22

Malpractice in the Bread Baking

The misunderstanding of the role of the whole-kernel ingredients in the preservation of the bread nutritional quality causes the main malpractices in the bread baking. The effect of the continuous increase in the reduction of the relative risk of the main morbidities has clearly demonstrated in a comprehensive review and meta-analysis as discussed above. However, along with this wide-ranging article and even in the comment invited by the editors (Goodlad and Englyst 2001), the main advantage or evenly the sole effect of the whole-grain has summarized as the effect of the carbohydrate quality or the quality of the dietary fiber. Such a presentation misleads the public to consider that incorporation of isolated dietary fiber into the bakery products might have an additional advantage in the nutritional quality. As pointed out along the present book, the advantage of the whole-grain has produced by the fermentative activity of the dietary fiber concomitantly with the activity of all other micro-ingredients, and other ingredients, embedded in the whole-wheat kernel. The assurance of the presence of all micro-ingredients and their quality preserves the whole-grain quality. The carbohydrate quality (ie, dietary fiber, whole-grains or pulses, dietary glycaemic index, or glycaemic load) and mortality and the incidence of a wide range of non-communicable diseases and their risk factors have counted for almost the sole factor for whole-grain quality. In this most extensive systematic review and meta-­ analyses of prospective studies and clinical trials reporting on the relationship between the most widely studied indicators, the effects of all micronutrients and in particular the anti-oxidants have not mentioned. A major false conclusion of such a study specifies that dietary fiber as defined by Codex Alimentarius is naturally occurring in foods but can be extracted from foods or synthesized and added into manufactured foods (Goodlad and Englyst 2001).

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Admixing of Preparatory Fibers The oat straw fiber is preparatory with low available carbohydrates that absorb water up to ×7 times of its weight. Except for oat straw preparations some other isolated dietary fiber prevails in the baking industry. Admixing of such a preparatory to many products of bakery, snacks, dairy, and meat, enables the retailers to sell more water at the price of the major product. When added to the bakery products, oat fiber allows for the production of low carbohydrate bread, pastries, muffins, bagels, tacos, and tortillas. Oat fiber is not the sole preparatory but more other preparations such as okra (a soy product) used to sell the higher content of water. All of these water absorbents leave a wide opening to mislead the consumer. Isolated dietary fiber nay admixed to the refined flour or the whole-wheat flour. With the increase of the isolated dietary fiber, there is an increase in the water content with a decrease in energy content but without any nutritional value. Such a bread termed “light bread” just because it contains a higher water content. Nobody has ever shown that the energy content of the “light bread” has a lower capacity to induce weight gain than the same energy content of the bread with lower water content. The consumer is thoroughly misled by the nutritional labeling of the “light bread”. Admixing of the industrial preparations of the dietary fiber to the dough increases its content in the bread. The “light bread” may contain up to 45% water without any nutritional quality and with dietary fiber pretend to acquire any nutritional advantage.

Sensible nutritional labeling of the whole-bread items has a high capacity to advance nutritional quality. No other food item consumed to a higher extent than the consumption of the staple bread items. The bakery and the retailing networks are most enthusiastic to have the food labeling with their needs because the bread consumption as the staple food has a marked impact on the consumption and pricing of many other food items. The health authorities and the food regulations are responsible to minimize the episodes of the malpractice in the bread prepared for the staple consumption and they retain the power to perform such a mission. The current regulations for food labeling, in most of the countries, do not support the identification of the severe malpractice in the marketing of the whole-wheat bread.

No convincing evidence to suggest that non-digestible carbohydrates per se are beneficial to human health. Definition of any non-digestible carbohydrate as a dietary fiber is very worryingly because it diverts attention from the original concept of the advantage of the unrefined plant foods which had proven as beneficial to health (Goodlad and Englyst 2001).

Salt Excess

397

The authorities of the food labeling corporates with such misleading because of the dietary labeling regulations do not distinguish between the content of the native dietary fiber and the admixed dietary fiber that isolated from the foreign materials. The replacement of the foreign isolated dietary for the native dietary fiber decreases remarkably the content of all of the micronutrients that comprise the major nutritional advantage of the whole-wheat and that normally many of them bound covalently to the carbohydrate and other residues embedded in the bran fraction.

Flour Milling Failure Presently, the milling technique appears to be the weakest link of the bread production in the preservation of the total anti-oxidant capacity and other micronutrients with the high nutritional value. While the decrease in the baking qualities of the flour immediately alarms the baker to inform the milling plant to improve the flour quality, the decrease in the anti-oxidant capacity is not a quality of concern. The dietary fiber intake versus the antioxidants intake In many citations, the dietary fiber of the whole-wheat counted as the trigger for the decrease in the relative risk of the health burdens. Such a statement remarkably misleads the nutritional facts. No study has shown to distinguish between the nutritional effect of the fiber versus the antioxidants and the other micro-ingredients of the wheat such as the choline, betaine, yellow pigments, vitamins, and some other micronutrients. There are claims that dietary fiber is the ingredient with the typical alleviative effects on the decrease of the incidence of the non-communicable diseases (NCD). Thus, not surprising isolated dietary fiber without any additional ingredient may replace the native ingredients with a big commercial success.

Salt Excess Sodium chloride (NaCl) is a major taste contributor to food. A reduction of the salt in the food products leads to less intense taste and flavor. The current challenge for the food producers is to develop products with a reduced salt content but an unimpaired and consistent taste. The milling procedures for the traditional refined flours have well established, but not the milling procedure of the whole-grain flours that are produced by a variety of techniques and result in the flours with widely different particle sizes and functionalities (Doblado-Maldonado et al. 2012). The particle size distribution of the flour is the most critical quality for baking bread with satisfactory features.

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The salt (sodium chloride) is an integral ingredient of almost all bread loaves. Since the sodium consumed only as sodium chloride, its content designated commonly as NaCl. The NaCl (salt) is higher than the Na weight by ×2.5. Adding of the Na to the dough has three main targets: (a) Increase the bread palatability to advance the marketing. (b) Improve the technical quality of the dough mixing and baking. (c) Increase in shelf life. The volatile aroma compounds impart flavor to food, and the volatile fraction of bread is a highly complex mixture with ~600 volatile compounds reported to present in the breadcrumb. The yeast metabolism has a key role in the development of the aroma profile of the bread. The Na ions have a direct impact on yeast activity. In addition to the ethanol and the carbon dioxide, many low-molecular-weight flavor compounds such as further alcohols, aldehydes, acids, esters, sulfides and carbonyl compounds produced by the yeast. These volatile compounds are essential contributors to the flavor of fermented foods and beverages. The reducing activity of the yeast during the bread dough fermentation also has a critical impact on the bread aroma. The unsaturated aldehydes derived from the oxidation of the linoleic acid to fatty odors in the wheat bread. The reduction of these unsaturated volatile compounds by the yeast to their corresponding alcohols has an impact on the bread aroma; as such, a variation in yeast activity results in the altered aroma of the bread. A reduction in the NaCl from the standard concentration of 1.2% to 0.3% increased the yeast activity. The NaCl reduction does not influence the volatile aroma of the bread significantly and the consumers, in general, are not able to recognize any reduced amounts of the salt in the odor of the breadcrumb (Belz et al. 2017). The NaCl serves to stabilize the yeast fermentation, enhance product flavor, strengthen the gluten network, increase the dough mixing time for increased protein-­ protein interactions, imparts dough properties such as extensibility, viscosity, elasticity, cohesiveness, and contributes to the water absorption. Once the NaCl added, charged sites on the protein surface become screened allowing the proteins to interact and aggregate through hydrophobic interactions. Consequently, the hydration of the gluten proteins reduces and the dough formed is stronger. Upon the reducing of the Na levels, the dough rheology and handling can compromise due to a sticky dough phenomenon that causes major processing issues and poor quality of the final product. The NaCl is necessary for strengthening the gluten network and enhancing the dough stability, stabilizes the yeast fermentation, and enhance the product flavor. The challenge of the decreasing or removing the salt from the bread formulations, when compared to other processed foods, is not only about the loss of the flavor, but also about the loss of the dough handling properties and the final bread product quality (Avramenko et al. 2018). The bread is a major contributor to the NaCl intake.

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To achieve the reduction in the salt intake the ingredient reformulation of the dough and process adaptations are necessary. To reduce the NaCl level in the baked goods, it is first important to gain a fundamental understanding of its roles from both techno-functional and sensory aspects. The industry undertakes efforts to reduce the NaCl content in the bakery products. At least, it is also the responsibility of the consumer to more openly accept the salt-reduced products and avoid the general action of adding more salt to a product before consuming it (Silow et  al. 2016). Increased in the NaCl intake >8 g/d has shown to exert a relative risk for mortality and NCD in comparison to the intake >1.4–1.5 > 8 g/d (O’Donnell et al. 2011; Lelli et al. 2018; Cook et al. 2016; Engberink et al. 2017). The high relative risk produced by the higher Na intake and the dominance of the Na-bread in the Na intake has driven the WHO and the health authorities in some countries to recommend a remarkable reduction in the Na intake and the Na content in the bread. The lowest relative risk for the mortality observed at the range of 3–5.5 g/d (O’Donnell et al. 2011; Lelli et al. 2018; Engberink et al. 2017). The Na urine excretion (that is lower than the Na intake) or the total Na intake is 50 g/d (Chen et al. 2016). The Chinese consumers favor the consumption of the high quality refined rice while the brown rice production is ~1.2% of the total output. Commonly, the consumer wants to buy brown rice or whole-wheat food cannot find the products on the supermarket shelves (Feng 2014). In a Shanghai study, several cultural barriers to the acceptance of the brown rice in the Chinese adults have identified. Before tasting the brown rice, the majority of the participants considered the brown rice inferior to the white rice in the terms of the taste and the quality and felt it unlikely that the individuals would change their habitual rice staple. However, after tasting the brown rice and learning about its nutritional value, most expressed willingness to consume the brown rice and participate in a future long-term brown rice intervention study to lower the risk of diabetes (Zhang et al. 2010). For years, the Indian consumers have preferred the white rice to the brown rice because of perceptions that it is of better quality, whiter, cleaner and is associated with the higher socioeconomic status. A need to aggressively promote the brown rice, highlighting its nutritive properties and the health benefits, was suggested by all participants in this study. These key findings suggest that the promotion of brown rice should occur in a stepwise process (Sudha et al. 2013).

The Advantage of the Brown (Whole) Rice

405

The Wheat Versus Rice Nutritional Quality In most of the articles claim for the advantage of the whole-wheat intake, the high content of the dietary fiber in the whole-wheat flour versus the low content in the refined flour, terms as the main factor responsible for the nutritional advantage of the whole-wheat flour. An excellent example of such an approach has presented in a comprehensive review and meta-analysis for the advantage of the whole-wheat products (Chambers et al. 2019). Only in some of the articles, the presence of the high content of the anti-oxidants also mentioned. The limited number of studies conducted with the effect of the whole-rice, open us a window to explore the effects of the grain ingredients. The wheat kernel contains a much higher content of the bran and the dietary fiber than the rice kernel. Accordingly, the difference between the wholegrain and the refined product is ~3 times higher for wheat kernel than for the rice kernel. The whole-wheat flour contains ~10% higher content of the dietary fiber and the vast majority of the anti-oxidants than the refined flour (Table 4.1, Fig. 4.4). The brown rice contains only 4.7% dietary fiber and the white rice contains 1.1% dietary fiber (Ross et al. 2015). The brown rice (unpolished) that contains the high content of the polyphenols and the other related micronutrients has a nutritional advantage upon the wheat in the phenol type with the high content of the 88% bound phenols while only 12% are free. In the wheat kernel, the bound phenols comprise 75% of the total phenols that still is much higher than in most of the edible food items. There is a claim that the bound phenols are more effective than the free phenols in the alleviative effect on the decrease on the morbidity incidence and in particular, in the case of the colon cancer, because the fiber does not decompose in the upper gut and digested only in the colon. Thus, the bound anti-oxidant compounds comprise a slow-released mechanism when they released from the dietary fiber matrix in the colon. When the free anti-oxidants reach the small intestine a high content destructed by the digestive processes on the upper gut (Acosta-Estrada et al. 2014). The divergence composition between the wheat kernel and the rice kernels and their effects on the decrease of the relative risks of the health burdens leave us a wide room for the inquiry of the mechanism responsible for the nutritional advantage of the whole-grain. Even in the limited data of the advantage of the whole-rice intake, such an intake has presumably a pivotal role in the decrease of the incidence of the relative risk of diabetes type 2. The diabetes type 2 mentioned often as the most threatening health burden in China and India with some supported studies. Unfortunately, the information for the other NCD (non-communicable disease) is most restricted.

The Advantage of the Brown (Whole) Rice Since the consumption of brown rice is most limited worldwide, the common nutritional questionnaires do not distinguish between the consumption of the white- and the brown rice. Thus, the data on brown rice intake and chronic diseases are

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restricted. In some studies where the alleviative effect of the brown rice claimed, the brown rice evaluated together with the whole-wheat and therefore no claim for the advantage of the brown rice can support. Thus, in the studies where the effect of the rice intake on the morbidity indexes have studied (Saneei et al. 2017), we cannot get a conclusion for the advantage for the brown rice. The analysis of 197 k subjects, in follow-up studies, showed that a higher intake of the white rice (5 vs 0.2 serv/w) associated with a higher risk 1.17 of type 2 diabetes. In contrast, a higher intake of the brown rice (2 vs 0.2 serv/w) associated with a 0.89 lower risk of type 2 diabetes. The authors consider that replacing of 50 g/d (uncooked), intake of the brown rice for the same amount of the white rice associated with a 16% lower risk of the type 2 diabetes (Sun et al. 2010). In a small study conducted in the Purdue University, in the USA the effect the whole-grain brown rice versus the white rice has evaluated for the gastric emptying rate. The brown rice displayed a slower gastric emptying rate than the white rice regardless of the variation in the amylose content and in vitro starch digestion rates which appears to be related to the physical presence of the bran layer. The extended gastric emptying of the brown rice explains in part the comparably low glycemic response observed for the brown rice (Pletsch and Hamaker 2018). In the absence of the wide-scaled epidemiological studies describing the beneficial effect of the whole-rice, many articles have investigated the effects of the rice bran, isolated compounds with animal experimentation, and small group subjects with some excellent results. A considerable number of publications have described the alleviative effects of the rice bran and its bioactive compounds on the beneficial effects on human health (Friedman 2013). However, in our days with enormous data accumulated for the nutrition science, evidence collected from small-scaled experimentations or animal experimentation cannot support conclusive nutritional recommendations while the wide-scaled epidemiological studies required.

References Acosta-Estrada BA, Gutiérrez-Uribe JA, Serna-Saldívar SO (2014) Bound phenolics in foods, a review. Food Chem 152:46–55. https://doi.org/10.1016/j.foodchem.2013.11.093 Bang MA, Riep TV, Thinh NT, Song LH, Dung TT, Truong LV, Don LV, Ky TD, Pan D, Shaheen M, Ghoneum M (2010) Arabinoxylan rice bran ( MGN-3) enhances the effects of interventional therapies for the treatment of hepatocellular carcinoma: a three-year randomized clinical trial. Anticancer Res 30:5145–5152 Chambers ES, Byrne CS, Frost G (2019) Carbohydrate and human health: is it all about quality? Lancet 393:384–386. https://doi.org/10.1016/s0140-6736(18)32468-1 Chen GC, Tong X, Xu JY, Han SF, Wan ZX, Qin JB, Qin LQ (2016) Whole-grain intake and total, cardiovascular, and cancer mortality: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr 104:164–172. https://doi.org/10.3945/ajcn.115.122432 Fardet A, Rock E, Rémésy C (2008) Is the in vitro antioxidant potential of whole-grain cereals and cereal products well reflected in vivo? J Cereal Sci 48:258–276. https://doi.org/10.1016/j. jcs.2008.01.002

References

407

Feng T (2014) Present status, challenges, and plans for whole-grain food development in China. Cereal Foods World 59:36–37. https://doi.org/10.1094/CFW-59-1-0036 Friedman M (2013) Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells. J Agric Food Chem 61:10626–10641. https:// doi.org/10.1021/jf403635v Hu EA, Pan A, Malik V, Sun Q (2012) White rice consumption and risk of type 2 diabetes: meta-­ analysis and systematic review. BMJ 344:e1454. https://doi.org/10.1136/bmj.e1454 Hung PV (2016) Phenolic compounds of cereals and their antioxidant capacity. Crit Rev Food Sci Nutr 56:25–35. https://doi.org/10.1080/10408398.2012.708909 Liu L, Guo J, Zhang R, Wei Z, Deng Y, Guo J, Zhang M (2015) Effect of degree of milling on phenolic profiles and cellular antioxidant activity of whole-brown rice. Food Chem 185:318–325. https://doi.org/10.1016/j.foodchem.2015.03.151 Pletsch EA, Hamaker BR (2018) Brown rice compared to white rice slows gastric emptying in humans. Eur J Clin Nutr 72:367–373. https://doi.org/10.1038/s41430-017-0003-z Ross AB, Colega MT, Lim AL, Silva-Zolezzi I, Macé K, Saw SM, Kwek K, Gluckman P, Godfrey KM, Chong YS, Chong MFF (2015) Whole-grain intake, determined by dietary records and plasma alkylresorcinol concentrations, is low among pregnant women in Singapore. Asia Pac J Clin Nutr 24:674–682. https://doi.org/10.6133/apjcn.2015.24.4.19 Saneei P, Larijani B, Esmaillzadeh A (2017) Rice consumption, incidence of chronic diseases and risk of mortality: meta-analysis of cohort studies. Public Health Nutr 20:233–244. https://doi. org/10.1017/S1368980016002172 Sudha V, Spiegelman D, Hong B, Malik V, Jones C, Wedick NM, Hu FB, Willett W, Bai MR, Ponnalagu MM, Arumugam K, Mohan V (2013) Consumer acceptance and preference study (CAPS) on brown and undermilled indian rice varieties in Chennai, India. J Am Coll Nutr 32:50–57. https://doi.org/10.1080/07315724.2013.767672 Sun Q, Spiegelman D, Dam RMV, Holmes MD, Malik VS, Willett WC, Hu FB (2010) White rice, brown rice, and risk of type 2 diabetes in US men and women. Arch Intern Med 170:961–969. https://doi.org/10.1001/archinternmed.2010.109 Tuncel NB, Yilmaz N (2011) Gamma-oryzanol content, phenolic acid profiles and antioxidant activity of rice milling fractions. Eur Food Res Technol 233:577–585. https://doi.org/10.1007/ s00217-011-1551-4 Wang Z, Gordon-Larsen P, Siega-Riz AM, Cai J, Wang H, Adair LS, Popkin BM (2017) Sociodemographic disparity in the diet quality transition among Chinese adults from 1991 to 2011. Eur J Clin Nutr 71:486–493. https://doi.org/10.1038/ejcn.2016.179 Wu F, Yang N, Touré A, Jin Z, Xu X (2013) Germinated brown rice and its role in human health. Crit Rev Food Sci Nutr 53:451–463. https://doi.org/10.1080/10408398.2010.542259 Zhang G, Malik VS, Pan A, Kumar S, Holmes MD, Spiegelman D, Lin X, Hu FB (2010) Substituting brown rice for white rice to lower diabetes risk: a focus-group study in Chinese adults. J Am Diet Assoc 110:1216–1221. https://doi.org/10.1016/j.jada.2010.05.004 Zhou Z, Chen X, Zhang M, Blanchard C (2014) Phenolics, flavonoids, proanthocyanidin and antioxidant activity of brown rice with different pericarp colors following storage. J Stored Prod Res 59:120–125. https://doi.org/10.1016/j.jspr.2014.06.009

Chapter 24

The Bread Consumption

The Intake of the Whole-Grain in Some Countries The Whole-Grain publication of the European Commission (Whole-Grain European Commission 2007), gives a comparative image of the distribution of the whole-­grain intake, g/d. within the 28 European countries. For the ages of 65–70, the average of the daily intake is 43 g/capita, with a 4% higher intake of females. As the whole-wheat bread is a main pillar of sensible nutrition, the knowledge of what motives driving the people to consume whole-wheat products is crucial to increase the whole-wheat intake. The distribution and the variation in the consumption of the whole-wheat at various regions and population segments may be the clue how to extract such knowledge. The current consumption of the whole-wheat bread versus refined-wheat bread continuously increases worldwide but at a very slow rate. Consistent differences in the consumption have observed across the population segments, countries and genders. Even the information for the consumption distribution of the whole-wheat bread is most limited, any comparison between any defined population segment may teach us the motives driving the people to consume whole-wheat bread and inform the health authorities how to pursue the people to consume the whole-bread for the refined products.

In some of the countries, the intake for females was higher by 7–9%. The intake at the ages of 20–60 y in many countries was much lower whereas somehow higher intakes observed at the ages of >75 for most of the countries. The lowest intake of 1.4 g/d observed in Hungary and the highest of 130 g/d in Germany (Table 24.1). © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_24

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Table 24.1  The daily whole-grain intake in the 28 European countries with a decreasing order for each range g/capita/d 20 y), only 14% males and 16% females consume whole-wheat bread (Cleveland et al. 2000) and in children (9–18 y), the consumption is ~6% whole-grain with almost no effect of the gender, ethnic origin and income (Keast et al. 2011). An increase of 50% in the whole-grain intake from 7.5 to 15 g/d observed from 2004 to 2014 in the US (Whole-Grains Statistics 2019). In German youngsters (13–18 y), the whole-grain intake stands for 9.4% for boys and girls with some trend of increase for toddlers (Alexy et al. 2010). In the UK, 91% of people consume white bread (Seal and Jones 2007). A couple of years ago, only 7% of the population consumed at least 3 servings of whole-grains/d (Doblado-­ Maldonado et  al. 2012). In Brazil, 2.6% of all bread consumed as whole-wheat bread (Pereira et al. 2017). Increased intake of whole-grain foods limited by a lack of consumer awareness of the health benefits of whole-grains, difficulty in identifying whole-grain foods in the marketplace, higher prices for some whole-grain foods, consumer perceptions of inferior taste and palatability, and lack of familiarity with the preparation methods (Kantor et al. 2001).

The Promotion of the Whole-Wheat Bread Intake Presumably, the health authorities at all levels nutritionists, editorial boards, funding agencies, and regulators are responsible for such a largest drawback in human nutrition. Consequently, the food industry and the retailing system have probably no motives to market the whole-wheat bread at the highest distribution and with the lowest price. Apparently, the advantage of whole-wheat vs. refined-products does not differ from the effect of other whole-grain vs. refined-products such as amaranth, barley, buckwheat, corn, millet, oats, rice, rye, sorghum, or teff. However, all other whole-­ cereals differ remarkably from whole-wheat in their health effects by the following points: (a) While the main wheat intake befalls after the flour has refined, the only minor part of the intake of the other grains, except rice, undergoes refining.

The Promotion of the Whole-Wheat Bread Intake

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(b) The alleviative effects of the kernel ingredients, well-identified and the lower relative risks for morbidities have precisely documented for the whole-wheat but have not shown with so many studies in all other cereals. (c) The grounds for any nutritional advantage mainly based on the medical evidence collected in the wide-scaled epidemiological surveys. Such evidence is available in the countries where wheat consumed as the main staple food. The medical evidence available for the evaluation of the whole-grain intake is scarcely collected in the countries where rice, corn, tubers, and other cereals and carbohydrate foods consumed as the staple foods. Presently, a consensus for the advantage of the whole-wheat products has widely reached, but still, the intake of the whole-wheat bread is slowly advent. Some obstacles are foreseen for the increase in the intake of the whole-­ wheat bread: (a) The dietary fiber embedded in the whole-wheat thought to be the main ingredient and almost the unique one with the alleviative health effects exerted by the whole-wheat. Some effects have also attributed to the increased content of some vitamins and minerals. Such an opinion considerably under-evaluate the major role of all the other ingredients that embedded in the wheat kernel. (b) Even the production expenses of the whole-wheat bread are apparently at the expenses range of the white bread, the price of the whole-wheat bread considerably higher than that of the white bread. (c) In many neighborhoods, the consumer has a lower availability for the whole-­ wheat bread than the availability for the white bread. In a survey performed in Illinois during 2015, the availability of whole-wheat bread found to be much lower than that of the white bread. Only 12% of stores offered 100% whole-­ wheat bread compared to 84% of stores offering white bread (Kern et al. 2017). All supermarkets carried whole-wheat bread, compared with 38% of the grocery stores and 7% of the convenience stores. Among the stores that carried the whole-wheat bread, on average, the supermarkets carried more varieties than did the groceries and the convenience stores. When available, the whole-wheat bread was least expensive in the supermarkets, compared with the groceries and the convenience stores (Leone et al. 2011). The staple foods have a long way of trial and the error fine-tuning of the product adjustment for local areas (the geographic and the social groups). However, presently a trend of the increase in the consumption of the whole-bread as the major staple food requires particular attention of the health authorities that presumably unavailable at the required scale. Therefore, the manufacturer should pay particular attention to the adjustment of the whole-bread to the local market. He should recognize that regional and demographic differences in liking may exist; studies conducted in other locations or on specific demographics may yield different attributes of importance. Additionally, preference mapping of consumer data with descriptive data displayed a lack of samples and attributes relating to a portion of consumers (Bernstein and Rose 2015).

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The health authorities in many countries have strongly recommended the consumers to shift into the consumption of the whole-bread. Even these ­recommendations highly affected the shifting trend (Mancino et al. 2008) still the rate is very (or even extremely) low while considering the advantage of such shifting. The nutritional interventions intended to modify the market environment faced by the consumers that are necessary to combat the rise of the food-related chronic diseases. Firms have incentives to create new products for health-conscious consumers who have a sufficiently high willingness-to-pay for healthier products. However, for a large share of the food market, firms have no incentive to enhance the healthiness of food products. This is in large part explained by the ‘unhealthy = tasty’ intuition, which creates a situation in which a single firm has no interest in deviating from the equilibrium by the enhancing (through reformulation) of the healthiness of its products. As long as the other firms do not modify the characteristics of their products, it is very hazardous for a firm to unilaterally modify the characteristics of its products. Therefore, the policy of intervention needed to provide incentives for all firms to reformulate their products. Rather than establishing minimum quality standards, a more optimal policy would be to define a consistent mix of actions integrating price policy, prescriptive labeling and advertising restrictions for products that do not comply with a given threshold. Such a policy is intended to provide incentives for firms to reformulate their products while avoiding banning certain products. Moreover, rather than targeting inter-group changes in the consumer diets, which has proved costly for the consumer, such a policy, designed at the level of product group, is designed to favor substitution within product group (Réquillart and Soler 2014).

 he Major Impairment in the Implementation T of the Whole-­Bread as the Major Staple Food The cost of the health food is about twice as that of the common foods in the market as found in a wide-scaled study in the US in the adult population (Singleton et al. 2017). The highest quality of the whole-wheat bread as one of the healthier food item, and concomitantly its lowest price among all healthy foods (Darmon and Drewnowski 2015), makes the whole-wheat bread a competitive item for all other “healthy food” items with a major difficulty to become a staple food at the widest scale. According to the Bureau of the Labor Statistics (Bureau of Labor Statistics 2019), the US city average price of the whole-wheat bread within the range of Jan-2015 until Jan-2015 was 2.00 $/pound while for white bread 1.39 $/pound. The whole-wheat price was higher by 44% than the price of the white bread. Presently, the market volume of the whole-wheat bread is much lower than that of the refined flour bread. With the increase in the market volume of the whole-wheat bread, a

References

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considerable price reduction forecasted. While other “health foods” more expensive than the whole-wheat, no motivation of the retailers to introduce the whole-wheat bread as the main staple food. Additionally, the whole-wheat bread might replace some other items of energy intake such as part of the sugar and the oils intake, potato, pasta, and replace of the refined flour in the cookie production. Penetration of the whole-wheat to the food-­ energy market as the main staple food will strongly oppose the main interests of the food industry, the retailing stores, and the food marketing networks. The whole-wheat by its composition and the high daily intake has a unique capacity to decrease substantially the relative risks of the main NCD (non-­ communicable diseases). On the other hand, control of the whole-bread quality and the whole-bread pricing strongly contradict the targets of the food industry, the retailing system, the advertising industry, and in particular the “health retailing system”. In such a major conflict, the probability that the motives of the free markets, the common economic competition, and the private entrepreneurs will ease the penetration of the whole-wheat products seems to be extremely low. The intervention in price control, oppose the liberal economic scholars throughout the entire globe. However, the whole-wheat bread is a unique food item that the penetration of its intake halted by the regular market streams.

References Alexy U, Zorn C, Kersting M (2010) Whole-grain in children’s diet: Intake, food sources and trends. Eur J Clin Nutr 64:745–751. https://doi.org/10.1038/ejcn.2010.94 Bernstein AJ, Rose DJ (2015) Preference mapping of commercial whole-wheat breads. Cereal Chem 92:278–283. https://doi.org/10.1094/CCHEM-07-14-0148-R Bureau of Labor Statistics (2019) United Stated Department of Labor, Databases, tables & calculators by subject. https://www.bls.gov/ Cleveland LE, Moshfegh AJ, Goldman JD, Albertson AM (2000) Dietary intake of whole-grains. J Am Coll Nutr 19:331S–338S. https://doi.org/10.1080/07315724.2000.10718969 Darmon N, Drewnowski A (2015) Contribution of food prices and diet cost to socioeconomic disparities in diet quality and health: a systematic review and analysis. Nutr Rev 73:643–660. https://doi.org/10.1093/nutrit/nuv027 Doblado-Maldonado AF, Pike OA, Sweley JC, Rose DJ (2012) Key issues and challenges in whole-wheat flour milling and storage. J Cereal Sci 56:119–126. https://doi.org/10.1016/j. jcs.2012.02.015 Kantor LS, Variyam JN, Allshouse JE, Putnam JJ, Lin BH (2001) Choose a variety of grains daily, especially whole-grains: a challenge for consumers. (The Dietary Guidelines). J Nutr 131:473S–486S Keast DR, Rosen RA, Arndt EA, Marquart LF (2011) Dietary modeling shows that substitution of whole-grain for refined-grain ingredients of foods commonly consumed by us children and teens can increase intake of whole-grains. J Am Diet Assoc 111:1322–1328. https://doi. org/10.1016/j.jada.2011.06.008 Kern DM, Auchnicloss AH, Stehr MF, Roux AVD, Moore LV, Kanter GP, Robinson LF (2017) Neighborhood prices of healthier and unhealthier foods and associations with diet quality: Evidence from the multi-ethnic study of atherosclerosis. Int J Environ Res Public Health 14:1242. https://doi.org/10.3390/ijerph14111394

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Leone AF, Rigby S, Betterley C, Park S, Kurtz H, Johnson MA, Lee JS (2011) Store type and demographic influence on the availability and price of healthful foods, Leon County, Florida, 2008. Prev Chronic Dis 8:A140. www.cdc.gov/pcd/issues/2011/nov/10_0231.htm Mancino L, Kuchler F, Leibtag E (2008) Getting consumers to eat more whole-grains: the role of policy, information, and food manufacturers. Food Policy 33:489–496. https://doi. org/10.1016/j.foodpol.2008.05.005 Pereira JL, de Castro MA, Hopkins S, Gugger C, Fisberg RM, Fisberg M (2017) Proposal for a breakfast quality index for brazilian population: Rationale and application in the Brazilian National Dietary Survey. Appetite 111:12–22. https://doi.org/10.1016/j.appet.2016.12.023 Réquillart V, Soler LG (2014) Is the reduction of chronic diseases related to food consumption in the hands of the food industry? Eur Rev Agric Econ 41:375–403. https://doi.org/10.1093/erae/ jbu010 Seal CJ, Jones AR (2007) Barriers to the consumption of all grain food. In: Marquart L, Jacobs DR, GH MI, Poutanen K, Reicks M (eds) Whole-grain, and health. Blackwell Publishing, Ames, pp 243–254 Singleton CR, Li Y, Duran AC, Zenk SN, Odoms-Young A, Zenk SN, Odoms-Young A, Powell LM (2017) Food and beverage availability in small food stores located in healthy food financing initiative eligible communities. Int J Environ Res Public Health 14:1242. https://doi. org/10.3390/ijerph14101242 Whole-Grain –European Commission (2007). http://healthgrain.org/wp-content/uploads/2017/12/ EU-JRC-Scientific-brief-on-Whole-Grans.pdf Whole-Grains Statistics (2019) Oldways Whole-Grain Council. https://wholegrainscouncil.org/ newsroom/whole-grain-statistics

Chapter 25

Industrial and Home-Made Baking of the Whole-Wheat Bread

The low-quality image of the whole-wheat flour bread connected to the fact that this bread is a very ancient product. For thousands of years, humans had consumed dark whole-wheat bread. For centuries and millennia, the milling system had left the peel (bran) on the seed and all bakery products were dark-colored. This is what people were used to eat.

The whole-flour price is lower than that of the refined-flour because it contains bran while the commodity bran price considerably lower than that of the refined flour. However, the baking expenses are somewhat higher because of the baking improvers added to the dough and because of the longer rising time (and longer proofing facilities) required to get the satisfactory dough rising and the satisfactory bread structure. A skillful knowledge and experience needed for the art of the admixing the baking additive to the whole-wheat dough to get the highest acceptability with the lowest expenses. Presumably, the higher price of the whole-wheat bread versus the refined-­ flour bread produced on the marketing systems.The whole-wheat flour has generally defined as flour that had produced by the milling of the whole-wheat seed. There are “blended” bakery products that contain the whole-wheat flour together with other types of flour (such as white wheat flour and rye flour). The whole-wheat flour portion in these blends has to follow the terms of the above definition for the whole-wheat flour. For a long time, the bread made of the whole-wheat flour, considered by the consumers to be “less tasty” (while many people still think so). The “less tasty” definition for the whole-wheat bread mainly related to the unpleasant gritty texture. There were also complains about the certain dry mouthfeel of the bread, and the lower specific volume with a low density of the whole-wheat bread.

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1_25

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25  Industrial and Home-Made Baking of the Whole-Wheat Bread

Within the industrial revolution, when the flour mills have learned to separate the bran from the seed and supply the bakers with white wheat flour, the baking industry had started developing products made of the white flour. From the aspect of the baking technology, white wheat flour is a better raw material, with a higher potential to produce tastier products. Few notorious products had appeared after the development of the white flour: the French baguette, the Italian focaccia, the English sponge bread, and the American soft hamburger buns. Until recently, the claim that the whole-wheat flour bakery products are “not tasty” was actually true because, during the process of the milling of the whole-­ seed, the bran segment was only partially ground. A lot of it remained relatively bigger than the rest of the seed segments. If you had examined such a flour, you could have seen the bran particles in the flour. A standard milling process of the white flour (without bran), will yield flour that at least 90% of it will pass through a 60 mesh sieve. Until recently, the mills could not grind the whole-wheat seeds to the desired particle size of 60 mesh (Table 25.1). The bran could be ground into particles of 45 mesh or bigger. These bran particles are the main reason for the gritty unpleasant mouthfeel. These particles had disturbed and damaged the genteel softness that is so typical in bakery products made of the white flour. Another aspect concerns the producers is that the industrial bakeries are working according to the worldwide food safety regulations (European Commission 1997). According to these regulations, wheat flour has to sieve before introduced into the dough mixer. When the whole-wheat flour sieved, a relatively large quantity of the bran sieved out (because of the bran particle size). This bran has to throw away, causing economic damage. During the last decades, the flour mills had succeeded by technical means to overcome the bran milling and these days the whole-wheat flour is ground nearly 100% uniformly. The technical methods to obtain the bran particle size used by the mills is similar to the rest of the seed and probably vary from one mill to another. So far, it is mostly commercially confidential. The organoleptic problems of the past had nearly gone but not completely. The whole-wheat flour contains much higher concentrations of tens and more anti-oxidant compounds which have an inhibitory effect on the enzymatic activities of the baker yeast (Kandil et al. 2012; Kong et al. 2016). Such inhibitory activities might require a particular preparation of the baker yeast and probably some higher amount. Another issue that has to be taken into consideration while working with the whole-wheat flour is the fact that the bran fibers disrupt the gluten net that holds the gas bubbles (CO2) created by the yeast fermentation. In order to obtain whole-wheat flour bakery products with volume, texture, and mouthfeel as close as possible to the white flour products, some bakery improvers and, other additives must use. The general recipes for bread made of whole-wheat flour presented in two versions (Table 25.2): industrial recipe and home-made recipe. In addition, the general recipe for the white-bread dough presented for comparison.

417

Classification of the Dough Ingredients Table 25.1  Mesh sieve conversion Mesh sieve Particle, μm

35 500

40 420

45 354

50 297

60 250

70 210

80 177

100 149

Table 25.2  Recipes for the whole-wheat bread

Basic ingredients Whole-wheat floura Cold water Wet yeast Margarine/shortening Additives 1 Vital gluten 2 Sugar 3 NaCl 4 L-ascorbic acid 5 Emulsifier –ssl 6 Preservative (Ca propionate) 7 Enzymesb 8 Glycerinc 9 Soy flourc 10 Dehydrated sour powderc

1 2 3 4

Whole-wheat bread recipe Industrial, 100 kg Home-made, 1 kg flour flour

Whitebread Industrial, 100 kg flour

100 kg 65 L 4.5–9 kg 3–5 kg

1000 g 650 mL 100 g 50 g

100 kg 65 L 3 kg 2 kg

8–10 kg 1.5–3 kg 1.2–1.5 kg 0.01 kg 210 publications). The list sorted according to the publication year. 1965 Medcalf DG, Gills KA (1965) Wheat starches, comparison of physiological properties. Ceral Chem 42:558–568. 1978 Lorenz K (1978) Selenium in Wheat and commercial wheat flours. Cereal Chem 55:287–294. 1980 Keagy PM, Borenstein B, Ranum P, Connor MA, Lorenz K, Hobbs WE, Hill G, Bachman AL, Boyd WA, Kulp K (1980) Natural levels of nutrients in commercially milled wheat flours. Vitamin analysis. Cerael Chem 57: 59–65. 1985 Mossé J, Huet JC, Baudet J (1985) The amino acid composition of wheat grain as a function of nitrogen content. J Cereal Sci 3:115–130. https://doi.org/10.1016/ S0733-5210(85)80022-9 1988 Dexter JE, Williams PC, Edwards NM, Martin DG (1988) The relationships between durum wheat vitreousness, kernel hardness and processing quality. J Cereal Sci 7:169–181.

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1

425

426

Appendix 1

1995 Graybosch RA, Peterson CJ, Baenzigert PS, Sheltont DR (1995) Environmental modification of hard red winter wheat flour protein composition. J Cereal Sci 22:45–51. 1998 Koivu T, Piironen V, Mattila P (1998) Phylloquinone (Vitamin K1) in cereal products. Cereal Chem 75:113–116. https://doi.org/10.1094/CCHEM.1998.75.1.113 1999 Slavin JL, Martini MC, Jacobs DR, Marquart L (1999) Plausible mechanisms for the protectiveness of whole-grains. Am J Clin Nutr 70:459S–463S. 2000 Bergman CJ, Gualberto DG, Campbell KG, Sorrells ME, Finney PL (2000) Kernel morphology variation in a population derived from a soft by hard wheat cross and associations with end-use quality traits. J Food Qual 23:391–407. https://doi. org/10.1111/j.1745-4557.2000.tb00566.x Chung OK, Ohm JB (2000) Cereal lipids. In: Kulp K, Ponte JG Jr (ed) Handbook of cereal science and technology, 2nd edn. American Institute of Baking Manhattan, Kansas. Chung OK, Ohm J-B (2000) Minor constituents of cereals. In: Kulp K, Ponte JG Jr (ed) Handbook of cereal science and technology, 2nd edn. American Institute of Baking Manhattan, Kansas. Clifford MN (2000) Miscellaneous phenols in foods and beverages – nature, occurrence and dietary burden. J Sci Food Agric 80:1126–1137. https://doi. org/10.1002/(SICI)1097-0010(20000515)80:73.0.CO;2–0 Posner ES (2000) Wheat. In: Kulp K, Ponte JG Jr (ed) Handbook of cereal science and technology, 2nd edn. American Institute of Baking Manhattan, Kansas. Shelton DR, Lee WL (2000) Cereal carbohydrates. In: Kulp K, Ponte JG Jr (ed) Handbook of cereal science and technology, 2nd edn. American Institute of Baking Manhattan, Kansas. Skrabanja V, Kovac B, Golob T, Liljeberg Elmståhl HGM, Björck IME, Kreft I (2001) Effect of spelt wheat flour and kernel on bread composition and nutritional characteristics. J Agric Food Chem 49:497–500. https://doi.org/10.1021/ jf000819w Troccoli A, Borrelli GM, Vita PD, Fares C, Di Fonzo N (2000) Durum wheat quality: a multidisciplinary concept. J Cereal Sci 32:99–113. https://doi.org/10.1006/ jcrs.2000.0322 Zandomeneghi M, Festa C, Carbonaro L, Galleschi L, Lenzi A, Calucci L (2000) Front-surface absorbance spectra of wheat flour: determination of carotenoids. J Agric Food Chem 48:2216–2221. https://doi.org/10.1021/jf9909003

Appendix 1

427

2001 Nandini CD, Salimath PV (2001) Carbohydrate composition of wheat, wheat bran, sorghum and bajra with good chapati/roti (Indian flat bread) making quality. Food Chem 73:197–203. https://doi.org/10.1016/S0308-8146(00)00278-8 Slavin JL, Jacobs D, Marquart L (2001) Grain processing and nutrition. Crit Rev Biotechnol 21:49–66. https://doi.org/10.1080/20013891081683 2002 Abdel-Aal ESM, Hucl P (2002) Amino acid composition and in vitro protein digestibility of selected ancient wheats and their end products. J Food Compos Anal 15:737–747. https://doi.org/10.1006/jfca.2002.1094 Adom KK, Liu RH (2002) Antioxidant activity of grains. J Agric Food Chem 50:6182–6187. https://doi.org/10.1021/jf0205099 2003 Groos C, Robert N, Bervas E, Charmet G (2003) Genetic analysis of grain protein-­ content, grain yield and thousand-kernel weight in bread wheat. Theor Appl Genet 106:1032–1040. https://doi.org/10.1007/s00122-002-1111-1 Fordyce FM (2003) Database of the iodine content of food and diets populated with data from published literature. British Geological Survey Commissioned Report, CR/03/84N. Løje H, Møller B, Laustsen AM, Hansen Å (2003) Chemical composition, functional properties and sensory profiling of einkorn (Triticum monococcum L.). J Cereal Sci 37:231–240. https://doi.org/10.1006/jcrs.2002.0498 Martin JM, Sherman JD, Lanning SP, Talbert LE, Giroux MJ (2008) Effect of variation in amylose content and puroindoline composition on bread quality in a hard spring wheat population. Cereal Chem 85:266–269. https://doi.org/10.1094/ CCHEM-85-2-0266 Matsuki J, Yasui T, Kohyama K, Sasaki T (2003) Effects of environmental temperature on structure and gelatinization properties of wheat starch. Cereal Chem 80:476–480. https://doi.org/10.1094/CCHEM.2003.80.4.476 Ross AB (2012) Analysis of alkylresorcinols in cereal grains and products using ultrahigh-pressure liquid chromatography with fluorescence, ultraviolet, and CoulArray electrochemical detection. J Agric Food Chem 60:8954–8962. https:// doi.org/10.1021/jf301332q Ross AB, Shepherd MJ, Schüpphaus M, Sinclair V, Alfaro B, Kamal-Eldin A, Åman P (2003) Alkylresorcinols in cereals and cereal products. J Agric Food Chem 51:4111–4118. https://doi.org/10.1021/jf0340456 2004 Konopka I, Kozirok W, Rotkiewicz D (2004) Lipids and carotenoids of wheat grain and flour and attempt of correlating them with digital image analysis of kernel surface and cross-sections. Food Res Int 37:429–438. https://doi.org/10.1016/j. foodres.2003.12.009

428

Appendix 1

Li W, Bollecker SS, Schofield JD (2004) Glutathione and related thiol compounds. I.  Glutathione and related thiol compounds in flour. J Cereal Sci 39:205–212. https://doi.org/10.1016/j.jcs.2003.10.003 Lyons GH, Genc Y, Stangoulis JCR, Palmer LT, Graham RD (2004) Selenium distribution in wheat grain, and the effect of postharvest processing on wheat selenium content. Biol Trace Elem Res 101:1–14. https://doi.org/10.1385/BTER 2005 Batifoulier F, Verny MA, Chanliaud E, Rémésy C, Demigné C (2005) Effect of different breadmaking methods on thiamine, riboflavin and pyridoxine contents of wheat bread. J Cereal Sci 42:101–108. https://doi.org/10.1016/j.jcs.2005.03.003 2006 Batifoulier F, Verny MA, Chanliaud E, Rémésy C, Demigné C (2006) Variability of B vitamin concentrations in wheat grain, milling fractions and bread products. Eur J Agron 25:163–169. https://doi.org/10.1016/j.eja.2006.04.009 Cheng Z, Su L, Moore J, Zhou K, Luther M, Yin J-J, Yu L (2006) Effects of post-­ harvest treatment and heat stress on the antioxidant properties of wheat. J Agric Food Chem 54:5623–5629. Ferreira DH, Haytowitz DB, Tassinari MA, Peterson JW, Booth SL (2006) Vitamin K contents of grains, cereals, fast-food breakfasts, and baked goods. J Food Sci 71:S66–S70. Landberg R, Kamal-Eldin A, Andersson R, Åman P (2006) Alkylresorcinol content and homologue composition in durum wheat (Triticum durum) kernels and pasta products. J Agric Food Chem 54:3012–3014. https://doi.org/10.1021/jf0530805 Wang M, Sapirstein HD, Machet AS, Dexter JE (2006) Composition and distribution of pentosans in millstreams of different hard spring wheats. Cereal Chem 83:161–168. https://doi.org/10.1094/CC-83-0161 2007 Abdel-Aal ESM, Young JC, Rabalski I, Hucl P, Fregeau-Reid J (2007) Identification and quantification of seed carotenoids in selected wheat species. J Agric Food Chem 55:787–794. https://doi.org/10.1021/jf062764p Adlercreutz H (2007) Lignans and human health. Crit Rev. Clin Lab Sci 44:483– 525. https://doi.org/10.1080/10408360701612942 Barron C, Surget A, Rouau X (2007) Relative amounts of tissues in mature wheat (Triticum aestivum L.) grain and their carbohydrate and phenolic acid composition. J Cereal Sci 45:88–96. https://doi.org/10.1016/j.jcs.2006.07.004 Dinelli G, Marotti I, Bosi S, Benedettelli S, Ghiselli L, Cortacero-Ramírez S, Carrasco-Pancorbo A, Segura-Carretero A, Fernández-Gutiérrez A (2007) Lignan profile in seeds of modern and old Italian soft wheat (Triticum aestivum L.) cultivars as revealed by CE-MS analyses. Electrophoresis 28:4212–4219. https://doi.org/10.1002/elps.200700301

Appendix 1

429

Greffeuille V, Abecassis J, Barouh N, Villeneuve P, Mabille F, L’Helgouac’h CB, Lullien-Pellerin V (2007) Analysis of the milling reduction of bread wheat farina: physical and biochemical characterisation. J Cereal Sci 45:97–105. https://doi.org/10.1016/j.jcs.2006.07.003 Liu RH (2007) Whole-grain phytochemicals and health. J Cereal Sci 46:207–219. https://doi.org/10.1016/j.jcs.2007.06.010 Saulnier L, Sado PE, Branlard G, Charmet G, Guillon F (2007) Wheat arabinoxylans: exploiting variation in amount and composition to develop enhanced varieties. J Cereal Sci 46:261–281. https://doi.org/10.1016/j.jcs.2007.06.014 2008 Andersson AAM, Kamal-Eldin A, Fraś A, Boros D, Åman P (2008) Alkylresorcinols in wheat varieties in the HEALTHGRAIN diversity screen. J Agric Food Chem 56:9722–9725. https://doi.org/10.1021/jf8011344 Ard LW (2008) Phenolic acids in wheat varieties in the HEALTHGRAIN diversity screen. 9732–9739. Danster N, Wolmarans P, Buitendag CS, Jager AD (2008) Energy and nutrient composition of South African wheat, wheat flour and bread. Nutritional Intervention Research Unit, Medical Research Council, Cape Town. Dewettinck K, Bockstaele FV, Kühne B, Walle DVD, Courtens TM, Gellynck X (2008) Nutritional value of bread: influence of processing, food interaction and consumer perception. J Cereal Sci 48:243–257. https://doi.org/10.1016/j. jcs.2008.01.003 Gebruers K, Dornez E, Boros D, Fraś A, Dynkowska W, Bedo Z, Rakszegi M, Delcour JA, Courtin CM (2008) Variation in the content of dietary fiber and components thereof in wheats in the healthgrain diversity screen. J Agric Food Chem 56:9740–9749. https://doi.org/10.1021/jf800975w Jiang X-L, Tian J-C, Hao Z, Zhang WD (2008) Protein content and amino acid composition in grains of wheat-related species. Agric Sci China 7:272–279. https://doi.org/10.1016/S1671-2927(08)60066-8 Korycińska M, Jaromin A, Kozubek A, Żarnowski R (2008) Alkylresorcinols in selected Polish rye and wheat cereals and whole-grain cereal products. J Agric Food Chem 56:7236–7242. Lampi AM, Nurmi T, Ollilainen V, Piironen V (2008) Tocopherols and tocotrienols in wheat genotypes in the healthgrain diversity screen. J Agric Food Chem 56:9716–9721. https://doi.org/10.1021/jf801092a Landberg R, Kamal-Eldin A, Andersson A, Vessby B, Åman P (2008) Alkylresorcinols as biomarkers of whole-grain wheat and rye intake: plasma concentration and intake estimated from dietary records. Am J Clin Nutr 87:832–838. Nurmi T, Nyström L, Edelmann M, Lampi AM, Piironen V (2008) Phytosterols in wheat genotypes in the healthgrain diversity screen. J Agric Food Chem 56:9710– 9715. https://doi.org/10.1021/jf8010678 Nurmi T, Nyström L, Edelmann M, Lampi AM, Piironen V (2008) Phytosterols in wheat genotypes in the healthgrain diversity screen. J Agric Food Chem 56:9710– 9715. https://doi.org/10.1021/jf8010678

430

Appendix 1

Ward JL, Poutanen K, Gebruers K, Piironen V, Lampi AM, Nyström L, Andersson AAM, Åman P, Boros D, Rakszegi M, Bedo Z, Shewry PR (2008) The ­HEALTHGRAIN cereal diversity screen: concept, results, and prospects. J Agric Food Chem 56:9699–9709. https://doi.org/10.1021/jf8009574 Yinian L, Jun W, Weizhong X, Daxin L, Weimin D (2008) Physicochemical properties of wheat fractionated by wheat kernel thickness and separated by kernel specific density. Cereal Chem 85:534–543. https://doi.org/10.1094/ CCHEM-85-4-0534 2009 Chen Y, Dunford NT, Edwards J, Carver B, Goad C (2009) Policosanol content and composition of wheat varieties as affected by environment. J Sci Food Agric 89:310–314. https://doi.org/10.1002/jsfa.3446 Clarke FR, Clarke JM, Knox RE (2011) Inheritance of stem solidness in eight durum wheat crosses. Can J Plant Sci 82:661–664. https://doi.org/10.4141/ p01-053 Kirchmann H, Mattsson L, Eriksson J (2009) Trace element concentration in wheat grain: results from the Swedish long-term soil fertility experiments and national monitoring program. Environ Geochem Health 31:561–571. https://doi. org/10.1007/s10653-009-9251-8 Moura FFD, Lewis KD, Falk MC (2009) Applying the FDA definition of whole-­ grains to the evidence for cardiovascular disease health claims. J Nutr 139:2220S–2226S. https://doi.org/10.3945/jn.109.112383 Schlemmer U, Frølich W, Prieto RM, Grases F (2009) Phytate in foods and significance for humans: food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food Res 53:330–375. https://doi.org/10.1002/ mnfr.200900099 Suchowilska E, Wiwart M, Borejszo Z, Packa D, Kandler W, Krska R (2009) Discriminant analysis of selected yield components and fatty acid composition of chosen Triticum monococcum, Triticum dicoccum and Triticum spelta accessions. J Cereal Sci 49:310–315. https://doi.org/10.1016/j.jcs.2008.12.003 Sun XY, Wu K, Zhao Y, Kong FM, Han GZ, Jiang HM, Huang XJ, Li RJ, Wang HG, Li SS (2009) QTL analysis of kernel shape and weight using recombinant inbred lines in wheat. Euphytica 165:615–624. https://doi.org/10.1007/ s10681-008-9794-2 Wu P, Tian JC, Walker CE, Wang FC (2009) Determination of phytic acid in cereals  – a brief review. Int J Food Sci Technol 44:1671–1676. https://doi. org/10.1111/j.1365-2621.2009.01991.x 2010 Andersson AAM, Åman P, Wandel M, Frølich W (2010) Alkylresorcinols in wheat and rye flour and bread. J Food Compos Anal 23:794–801. https://doi. org/10.1016/j.jfca.2010.03.012 Andersson AAM, Kamal-Eldin A, Åman P (2010) Effects of environment and variety on alkylresorcinols in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9299–9305. https://doi.org/10.1021/jf904526d

Appendix 1

431

Escarnot E, Agneessens R, Wathelet B, Paquot M (2010) Quantitative and qualitative study of spelt and wheat fibres in varying milling fractions. Food Chem 122:857–863. https://doi.org/10.1016/j.foodchem.2010.02.047 Fardet A (2010) New hypotheses for the health-protective mechanisms of whole-­ grain cereals: what is beyond fibre? Nutr Res Rev. 23:65–134. https://doi. org/10.1017/S0954422410000041 Fernandez-Orozco R, Li L, Harflett C, Shewry PR, Ward JL (2010) Effects of environment and genotype on phenolic acids in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9341–9352. https://doi.org/10.1021/jf102017s Fernandez-Orozco R, Li L, Harflett C, Shewry PR, Ward JL (2010) Effects of environment and genotype on phenolic acids in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9341–9352. https://doi.org/10.1021/jf102017s Gebruers K, Dornez E, Bedõ Z, Rakszegi M, Frás A, Boros D, Courtin CM, Delcour JA (2010) Environment and genotype effects on the content of dietary fiber and its components in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9353–9361. https://doi.org/10.1021/jf100447g Gomez-Becerra HF, Erdem H, Yazici A, Tutus Y, Torun B, Ozturk L, Cakmak I (2010) Grain concentrations of protein and mineral nutrients in a large collection of spelt wheat grown under different environments. J Cereal Sci 52:342–349. https://doi.org/10.1016/j.jcs.2010.05.003 Hejtmánková K, Lachman J, Hejtmánková A, Pivec V, Janovská D (2010) Tocols of selected spring wheat (Triticum aestivum L.), einkorn wheat (Triticum monococcum L.) and wild emmer (Triticum dicoccum Schuebl [Schrank]) varieties. Food Chem 123:1267–1274. https://doi.org/10.1016/j.foodchem.2010.05.064 Kariluoto S, Edelmann M, Piironen V (2010) Effects of environment and genotype on folate contents in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9324–9331. https://doi.org/10.1021/jf100251j Knödler M, Most M, Schieber A, Carle R (2010) A novel approach to authenticity control of whole-grain durum wheat (Triticum durum Desf.) flour and pasta, based on analysis of alkylresorcinol composition. Food Chem 118:177–181. https://doi.org/10.1016/j.foodchem.2009.04.080 Lampi AM, Nurmi T, Piironen V (2010) Effects of the environment and genotype on tocopherols and tocotrienols in wheat in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9306–9313. https://doi.org/10.1021/jf100253u Nurmi T, Lampi AM, Nyström L, Turunen M, Piironen V (2010) Effects of genotype and environment on steryl ferulates in wheat and rye in the HEALTHGRAIN diversity screen. J Agric Food Chem 58:9332–9340. https://doi.org/10.1021/ jf100170s Okarter N, Liu CS, Sorrells ME, Liu RH (2010) Phytochemical content and antioxidant activity of six diverse varieties of whole-wheat. Food Chem 119:249–257. https://doi.org/10.1016/j.foodchem.2009.06.021 Ramachandran A, Pozniak CJ, Clarke JM, Singh AK (2010) Carotenoid accumulation during grain development in durum wheat. J Cereal Sci 52:30–38. https:// doi.org/10.1016/j.jcs.2010.02.014

432

Appendix 1

Rao BN, Pozniak CJ, Hucl PJ, Briggs C (2010) Baking quality of emmer-derived durum wheat breeding lines. J Cereal Sci 51:299–304. https://doi.org/10.1016/j. jcs.2010.01.004 Shewry PR, Gebruers K, Andersson AAM, Åman P, Piironen V, Lampi AM, Boros D, Rakszegi M, Bedo Z, Ward JL (2011) Relationship between the contents of bioactive components in grain and the release dates of wheat lines in the HEALTHGRAIN diversity screen. J Agric Food Chem 59:928–933. https://doi. org/10.1021/jf103860x Zuchowski J, Jonczyk K, Pecio L, Oleszek W (2011) Phenolic acid concentrations in organically and conventionally cultivated spring and winter wheat. J Sci Food Agric 91:1089–1095. https://doi.org/10.1002/jsfa.4288 2011 Jonnalagadda SS, Harnack L, Liu RH, McKeown N, Seal C, Liu S, Fahey GC (2011) Putting the whole-grain puzzle together: health benefits associated with whole-grains—Summary of American Society for Nutrition 2010 Satellite Symposium. J Nutr 141:1011S–1022S. https://doi.org/10.3945/jn.110.132944 Rakha A, Åman P, Andersson R (2011) Dietary fiber in triticale grain: variation in content, composition, and molecular weight distribution of extractable components. J Cereal Sci 54:324–331. https://doi.org/10.1016/j.jcs.2011.06.010 Revanappa SB, Salimath P V. (2011) Phenolic acid profiles and antioxidant activities of different wheat Ttriticum aestivum l.) varieties. J Food Biochem 35:759– 775. https://doi.org/10.1111/j.1745-4514.2010.00415.x Shewry PR, Ward JL, Schaik FV, Ravel C, Charmet G, Rakszegi M, Bedo Z (2011) Genotype and environment effects on the contents of vitamins B1, B2, B3, and B6 in wheat grain. J Agric Food Chem 59:10564–10571. https://doi.org/10.1021/ jf202762b Shtangeeva I, Steinnes E, Lierhagen S (2011) Macronutrients and trace elements in rye and wheat: similarities and differences in uptake and relationships between elements. Environ Exp Bot 70:259–265. https://doi.org/10.1016/j. envexpbot.2010.09.013 Souza EJ, Guttieri M, Sneller C (2011) Nutritional profile of whole-grain soft wheat flour. Cereal Chem 88:473–479. https://doi.org/10.1094/CCHEM-05-11-0066 Tavajjohl M, Yasrebil J, Karimianl N, Olamal V (2011) Phytic acid concentration and phytic acid: zinc molar ratio in wheat cultivars and bread flours, fars province Iran, J Agric Sci Technol 13:743–755. Žilić S, Hadži-Tašković Šukalović V, Dodig D, Maksimović V, Maksimović M, Basić Z (2011) Antioxidant activity of small grain cereals caused by phenolics and lipid soluble antioxidants. J Cereal Sci 54:417–424. https://doi.org/10.1016/j. jcs.2011.08.006 Žilić S, Dodig D, Šeremešić MM, Kandić V, Kostadinović M, Prodanović S, Savić D (2011) Small grain cereals compared for dietary fibre and protein contents. Genetika 43:381–395. https://doi.org/10.2298/GENSR1102381Z

Appendix 1

433

2012 Ross AB, Bourgeois A, N-Macharia H, Kochhar S, Jebb SA, Brownlee IA, Seal CJ (2012) Plasma alkylresorcinols as a biomarker of whole-grain food consumption in a large population: results from the WHOLEheart Intervention Study. Am J Clin Nutr 95:204–211. https://doi.org/10.3945/ajcn.110.008508.204 Corol D-I, Beale MH, Shewry PR, Ward JL, Ravel C, Charmet G, Raksegi M, Bedo Z (2012) Effects of genotype and environment on the contents of betaine, choline, and trigonelline in cereal grains. J Agric Food Chem 60:5471–5481. https:// doi.org/10.1021/jf3008794 Irakli MN, Samanidou VF, Biliaderis CG, Papadoyannis IN (2012) Development and validation of an HPLC-method for determination of free and bound phenolic acids in cereals after solid-phase extraction. Food Chem 134:1624–1632. https:// doi.org/10.1016/j.foodchem.2012.03.046 Konopka I, Tanska M, Faron A, Stçpien A, Wojtkowiak K (2012) Comparison of the phenolic compounds, carotenoids and tocochromanols content in wheat grain under organic and mineral fertilization regimes. Molecules 17:12341–12356. https://doi.org/10.3390/molecules171012341 Leoncini E, Prata C, Malaguti M, Marotti I, Segura-Carretero A, Catizone P, Dinelli G, Hrelia S (2012) Phytochemical profile and nutraceutical value of old and modern common wheat cultivars. PLoS One 7:45997. https://doi.org/10.1371/ journal.pone.0045997 Nurmi T, Lampi AM, Nyström L, Hemery Y, Rouau X, Piironen V (2012) Distribution and composition of phytosterols and steryl ferulates in wheat grain and bran fractions. J Cereal Sci 56:379–388. https://doi.org/10.1016/j. jcs.2012.04.010 Ragaee S, Guzar I, Abdel-Aal E-SM, Seetharaman K (2012) Bioactive components and antioxidant capacity of Ontario hard and soft wheat varieties. Can J Plant Sci 92:19–30. https://doi.org/10.4141/CJPS2011-100 Shewry PR, Charmet G, Branlard G, Lafiandra D, Gergely S, Salgó A, Saulnier L, Bedo Z, Mills ENC, Ward JL (2012) Developing new types of wheat with enhanced health benefits. Trends Food Sci Technol 25:70–77. https://doi. org/10.1016/j.tifs.2012.01.003 Stevenson L, Phillips F, O’sullivan K, Walton J (2012) Wheat bran: its composition and benefits to health, a European perspective. Int J Food Sci Nutr 63:1001– 1013. https://doi.org/10.3109/09637486.2012.687366 Zhang Y, Wang L, Yao Y, Yan J, He Z (2012) Phenolic acid profiles of Chinese wheat cultivars. J Cereal Sci 56:629–635. https://doi.org/10.1016/j.jcs.2012.07.006 Žilić S, Serpen A, Akıllıoğlu G, Janković M, Gökmen V (2012) Distributions of phenolic compounds, yellow pigments and oxidative enzymes in wheat grains and their relation to antioxidant capacity of bran and debranned flour. J Cereal Sci 56:652–658. https://doi.org/10.1016/j.jcs.2012.07.014

434

Appendix 1

2013 Acquistucci R, Melini V, Carbonaro M, Finotti E (2013) Bioactive molecules and antioxidant activity in durum wheat grains and related millstream fractions. Int J Food Sci Nutr 64:959–967. https://doi.org/10.3109/09637486.2013.825696 Andersson AAM, Andersson R, Piironen V, Lampi AM, Nyström L, Boros D, Fraś A, Gebruers K, Courtin CM, Delcour JA, Rakszegi M, Bedo Z, Ward JL, Shewry PR, Åman P (2013) Contents of dietary fibre components and their relation to associated bioactive components in whole-grain wheat samples from the HEALTHGRAIN diversity screen. Food Chem 136:1243–1248. https://doi. org/10.1016/j.foodchem.2012.09.074 Barak S, Mudgil D, Khatkar BS (2013) Relationship of gliadin and glutenin proteins with dough rheology, flour pasting and bread making performance of wheat varieties. LWT-Food Sci Technol 51:211–217. https://doi.org/10.1016/j. lwt.2012.09.011 Brandolini A, Castoldi P, Plizzari L, Hidalgo A (2013) Phenolic acids composition, total polyphenols content and antioxidant activity of Triticum monococcum, Triticum turgidum and Triticum aestivum: a two-years evaluation. J Cereal Sci 58:123–131. https://doi.org/10.1016/j.jcs.2013.03.011 Chen Y, Dunford NT, Goad C (2013) Phytochemical composition of extracts from wheat grain fractions obtained by tangential abrasive dehulling. LWT-Food Sci Technol 54:353–359. https://doi.org/10.1016/j.lwt.2013.07.007 Chen Y, Dunford NT, Goad C (2013) Tangential abrasive dehulling of wheat grain to obtain policosanol and phytosterol enriched fractions. J Cereal Sci 57:258– 260. https://doi.org/10.1016/j.jcs.2012.12.002 Ciccoritti R, Carbone K, Bellato S, Pogna N, Sgrulletta D (2013) Content and relative composition of some phytochemicals in diploid, tetraploid and hexaploid Triticum species with potential nutraceutical properties. J Cereal Sci 57:200– 206. https://doi.org/10.1016/j.jcs.2012.07.009 Fayaz F, Mardi M, Aghaee M, Darvish F, Talebi R (2013) Phenotypic diversity analysis of grain yield and yellow pigment content in germplasm collected from Iranian durum wheat (Triticum turgidum L.) landraces. Arch Agron Soil Sci 59:1339–1357. https://doi.org/10.1080/03650340.2012.708927 Frølich W, Åman P, Tetens I (2013) Whole-grain foods and health – a Scandinavian perspective. Food Nutr Res 57:18503. https://doi.org/10.3402/fnr.v57i0.18503 Giambanelli E, Ferioli F, Koçaoglu B, Jorjadze M, Alexieva I, Darbinyan N, D’Antuono LF (2013) A comparative study of bioactive compounds in primitive wheat populations from Italy, Turkey, Georgia, Bulgaria and Armenia. J Sci Food Agric 93:3490–3501. https://doi.org/10.1002/jsfa.6326 Kaur KD, Jha A, Sabikhi L, Singh AK (2014) Significance of coarse cereals in health and nutrition: a review. J Food Sci Technol 51:1429–1441. https://doi. org/10.1007/s13197-011-0612-9 Koehler P, Wieser H (2013) Chapter 2: Chemistry of cereal grains. In: Gobbetti M, Gänzle M (ed) Handbook on sourdough biotechnology. Springer, New  York. https://doi.org/10.1007/978-1-4614-5425-0_2

Appendix 1

435

Lachman J, Hejtmánková K, Kotíková Z (2013) Tocols and carotenoids of einkorn, emmer and spring wheat varieties: selection for breeding and production. J Cereal Sci 57:207–214. https://doi.org/10.1016/j.jcs.2012.05.011 Ndolo VU, Beta T (2013) Distribution of carotenoids in endosperm, germ, and aleurone fractions of cereal grain kernels. Food Chem 139:663–671. https://doi. org/10.1016/j.foodchem.2013.01.014 Pongrac P, Kreft I, Vogel-Mikuš K, Regvar M, Germ M, Vavpetič P, Grlj N, Jeromel L, Eichert D, Budič B, Pelicon P (2013) Relevance for food sciences of quantitative spatially resolved element profile investigations in wheat (Triticum aestivum) grain. J R Soc Interface 10:20130296. https://doi.org/10.1098/ rsif.2013.0296 Pozniak CJ (2013) CDC desire durum wheat. Can J Plant Sci 93:1265–1270. https:// doi.org/10.4141/cjps2013-214 Punder KD, Pruimboom L (2013) The dietary intake of wheat and other cereal grains and their role in inflammation. Nutrients 5:771–787. https://doi. org/10.3390/nu5030771 Sapirstein HD, Wang M, Beta T (2013) Effects of debranning on the distribution of pentosans and relationships to phenolic content and antioxidant activity of wheat pearling fractions. LWT-Food Sci Technol 50:336–342. https://doi.org/10.1016/j. lwt.2012.04.030 Schulthess A, Schwember AR (2013) Improving durum wheat (Triticum turgidum L. var. durum) grain yellow pigment content through plant breeding. Cience Investig Agrar 40:475–490. https://doi.org/10.4067/ s0718-16,202,013,000,300,002 Shewry PR, Hawkesford MJ, Piironen V, Lampi AM, Gebruers K, Boros D, Andersson AAM, Åman P, Rakszegi M, Bedo Z, Ward JL (2013) Natural variation in grain composition of wheat and related cereals. J Agric Food Chem 61:8295–8303. https://doi.org/10.1021/jf3054092 Wang L, Yao Y, He Z, Wang D, Liu A, Zhang Y (2013) Determination of phenolic acid concentrations in wheat flours produced at different extraction rates. J Cereal Sci 57:67–72. https://doi.org/10.1016/j.jcs.2012.09.013 Yu L, Nanguet A-L, Beta T (2013) Comparison of Antioxidant properties of refined and whole-wheat flour and bread. Antioxidants 2:370–383. https://doi. org/10.3390/antiox2040370 Zhao H, Guo B, Wei Y, Zhang B (2013) Multi-element composition of wheat grain and provenance soil and their potentialities as fingerprints of geographical origin. J Cereal Sci 57:391–397. https://doi.org/10.1016/j.jcs.2013.01.008 2014 Andersson AAM, Dimberg L, Åman P, Landberg R (2014) Recent findings on certain bioactive components in whole-grain wheat and rye. J Cereal Sci 59:294– 311. https://doi.org/10.1016/j.jcs.2014.01.003 Ficco DBM, Simone V De, Colecchia SA, Pecorella I, Platani C, Nigro F, Finocchiaro F, Papa R, Vita PD (2014) Genetic variability in anthocyanin composition and nutritional. J Agric Food Chem 62:8686–8695. https://doi. org/10.1021/jf5003683

436

Appendix 1

Hazard B, Zhang X, Naemeh M, Dubcovsky J (2014) Registration of durum wheat germplasm lines with combined mutations in SBEIIa and SBEIIb genes conferring increased amylose and resistant starcha and genes conferring ­ increased amylose and resistant starch. J Plant Regist 8:334. https://doi. org/10.3198/jpr2014.02.0007crg Hidalgo A, Brandolini A (2014) Nutritional properties of einkorn wheat (Triticum monococcum L.). J Sci Food Agric 94:601–612. https://doi.org/10.1002/ jsfa.6382 Hidalgo A, Fongaro L, Brandolini A (2014) Wheat flour granulometry determines colour perception. Food Res Int 64:363–370. https://doi.org/10.1016/j. foodres.2014.06.050 Jiang X, Wu P, Tian J (2014) Genetic analysis of amino acid content in wheat grain. J Genet 93:451–458. https://doi.org/10.1007/s12041-014-0408-6 Kaur KD, Jha A, Sabikhi L, Singh AK (2014) Significance of coarse cereals in health and nutrition: a review. J Food Sci Technol 51:1429–1441. https://doi. org/10.1007/s13197-011-0612-9 Knudsen KEB (2014) Fiber and nonstarch polysaccharide content and variation in common crops used in broiler diets. Poult Sci 93:2380–2393. https://doi. org/10.3382/ps.2014-03902 Ma D-Y, Sun D-X, Zuo Y, Wang C-Y, Zhu Y-J, Guo T-C (2014) Diversity of antioxidant content and its relationship to grain color and morphological characteristics in winter wheat grains. J Integr Agric 13:1258–1267. https://doi.org/10.1016/ S2095-3119(13)60573-0 Navas-Lopez JF, Ostos-Garrido FJ, Castillo A, Martín A, Gimenez MJ, Pistón F (2014) Phenolic content variability and its chromosome location in tritordeum. Front Plant Sci 5:10. https://doi.org/10.3389/fpls.2014.00010 Ndolo VU, Beta T (2014) Comparative studies on composition and distribution of phenolic acids in cereal grain botanical fractions. Cereal Chem 91:522–530. dx. doi.org/https://doi.org/10.1094/CCHEM-10-13-0225-R Pasha I, Saqib I, Butt MS, Randhawa MA, Saeed F, Waqas K (2014) Distribution of phenolic acids in milling fractions of spring wheats. Int J Food Prop 17:2052– 2062. https://doi.org/10.1080/10942912.2011.570470 Saeed F, Pasha I, Anjum FM, Sultan JI, Arshad M (2014) Arabinoxylan and arabinogalactan content in different spring wheats. Int J Food Prop 17:713–721. https://doi.org/10.1080/10942912.2012.654568 Su D, Lei BT, Li ZW, Cao Z-Z, Huang FD, Pan G, Ding Y, Cheng FM (2014) Influence of high temperature during filling period on grain phytic acid and its relation to spikelet sterility and grain weight in non-lethal low phytic acid mutations in rice. J Cereal Sci 60:331–338. https://doi.org/10.1016/j.jcs.2014.04.010 Wang T, He F, Chen G (2014) Improving bioaccessibility and bioavailability of phenolic compounds in cereal grains through processing technologies: a concise review. J Funct Foods 7:101–111. https://doi.org/10.1016/j.jff.2014.01.033 Yao X, Chu J, He X, Si C (2014) Grain yield, starch, protein, and n- different growth stages. J Cereal Sci 60:31–36. https://doi.org/10.1016/j.jcs.2014.01.012

Appendix 1

437

Yu A, Li Y, Ni Y, Yang W, Yang D, Cui Z, Wang Z, Yin Y (2014) Differences of starch granule distribution in grains from different spikelet positions in winter wheat. PLoS One 9:114342. https://doi.org/10.1371/journal.pone.0114342 Zhang Z, Smith C, Li W (2014) Extraction and modification technology of arabinoxylans from cereal by-products: a critical review. Food Res Int 65:423–436. https://doi.org/10.1016/j.foodres.2014.05.068 2015 Benincasa P, Galieni A, Manetta AC, Pace R, Guiducci M, Pisante M, Stagnari F (2015) Phenolic compounds in grains, sprouts and wheatgrass of hulled and non-­ hulled wheat species. J Sci Food Agric 95:1795–1803. https://doi.org/10.1002/ jsfa.6877 Brandolini A, Hidalgo A, Gabriele S, Heun M (2015) Chemical composition of wild and feral diploid wheats and their bearing on domesticated wheats. J Cereal Sci 63:122–127. https://doi.org/10.1016/j.jcs.2015.03.005 Brier N De, Gomand SV., Donner E, Paterson D, Delcour JA, Lombi E, Smolders E (2015) Distribution of minerals in wheat grains (Triticum aestivum L.) and in roller milling fractions affected by pearling. J Agric Food Chem 63:1276–1285. https://doi.org/10.1021/jf5055485 Erik K, Knudsen B (20518) Microbial Degradation of whole-grain complex carbohydrates and impact on short-chain fatty. Adv Nutr 6:206–213. https://doi. org/10.3945/an.114.007450.206 Escarnot E, Dornez E, Verspreet J, Agneessens R, Courtin CM (2015) Quantification and visualization of dietary fibre components in spelt and wheat kernels. J Cereal Sci 62:124–133. https://doi.org/10.1016/j.jcs.2015.01.003 Hucl P, Briggs C, Graf RJ, Chibbar RN (2015) Genetic gains in agronomic and selected end-use quality traits over a century of plant breeding of Canada western red spring wheat. Cereal Chem 92:537–543. https://doi.org/10.1094/ CCHEM-02-15-0029-R Jaworski NW, Lærke HN, Knudsen KEB, Stein HH (2015) Carbohydrate composition and in  vitro digestibility of dry matter and nonstarch polysaccharides in corn, sorghum, and wheat and coproducts from these grains1. J Anim Sci 93:1103–1113. https://doi.org/10.2527/jas.2014-8147 Kahraman K, Koksel H, Ng PKW (2015) Optimisation of the reaction conditions for the production of cross-linked starch with high resistant starch content. Food Chem 174:173–179. https://doi.org/10.1016/j.foodchem.2014.11.032 Laddomada B, Durante M, Minervini F, Garbetta A, Cardinali A, D’Antuono I, Caretto S, Blanco A, Mita G (2015) Phytochemical composition and anti-­ inflammatory activity of extracts from the whole-meal flour of Italian durum wheat cultivars. Int J Mol Sci 16:3512–3527. https://doi.org/10.3390/ ijms16023512 Lamsal RP, Beauchemin D (2015) Estimation of the bio-accessible fraction of Cr, As, Cd and Pb in  locally available bread using on-line continuous leaching method coupled to inductively coupled plasma mass spectrometry. Anal Chim Acta 867:9–17. https://doi.org/10.1016/j.aca.2015.02.047

438

Appendix 1

Ma D, Sun D, Li Y, Wang C, Xie Y, Guo T (2015) Effect of nitrogen fertilisation and irrigation on phenolic content, phenolic acid composition, and antioxidant ­activity of winter wheat grain. J Sci Food Agric 95:1039–1046. https://doi. org/10.1002/jsfa.6790 Marti A, Ulrici A, Foca G, Quaglia L, Pagani MA (2015) Characterization of common wheat flours (Triticum aestivum L.) through multivariate analysis of conventional rheological parameters and gluten peak test indices. LWT-Food Sci Technol 64:95–103. https://doi.org/10.1016/j.lwt.2015.05.029 Martini D, Taddei F, Ciccoritti R, Pasquini M, Nicoletti I, Corradini D, D’Egidio MG (2015) Variation of total antioxidant activity and of phenolic acid, total phenolics and yellow coloured pigments in durum wheat (Triticum turgidum L. var. durum) as a function of genotype, crop year and growing area. J Cereal Sci 65:175–185. https://doi.org/10.1016/j.jcs.2015.06.012 Mellado-Ortega E, Hornero-Méndez D (2015) Carotenoid profiling of hordeum chilense grains: the parental proof for the origin of the high carotenoid content and esterification pattern of tritordeum. J Cereal Sci 62:15–21. https://doi. org/10.1016/j.jcs.2014.12.005 Mellado-Ortega E, Atienza SG, Hornero-Méndez D (2015) Carotenoid evolution during postharvest storage of durum wheat (Triticum turgidum conv. durum) and tritordeum (×Tritordeum Ascherson et Graebner) grains. J Cereal Sci 62:134– 142. https://doi.org/10.1016/j.jcs.2015.01.006 Moore SA, Ai Y, Chang F, Jane JL (2015) Effects of alpha-amylase reaction mechanisms on analysis of resistant-starch contents. Carbohydr Polym 115:465–471. https://doi.org/10.1016/j.carbpol.2014.09.014 Ross AB, Colega MT, Lim AL, Silva-Zolezzi I, Macé K, Saw SM, Kwek K, Gluckman P, Godfrey KM, Chong YS, Chong MFF (2015) Whole-grain intake, determined by dietary records and plasma alkylresorcinol concentrations, is low among pregnant women in Singapore. Asia Pac J Clin Nutr 24:674–682. https:// doi.org/10.6133/apjcn.2015.24.4.19 Rosa-Sibakov N, Poutanen K, Micard V (2015) How does wheat grain, bran and aleurone structure impact their nutritional and technological properties? Trends Food Sci Technol 41:118–134. https://doi.org/10.1016/j.tifs.2014.10.003 Shewry PR, Hey S (2015) Do “ancient” wheat species differ from modern bread wheat in their contents of bioactive components? J Cereal Sci 65:236–243. https://doi.org/10.1016/j.jcs.2015.07.014 Thanhaeuser SM, Wieser H, Koehler P (2015) Spectrophotometric and fluorimetric quantitation of quality-related protein fractions of wheat flour. J Cereal Sci 62:58–65. https://doi.org/10.1016/j.jcs.2014.12.010 Yilmaz VA, Brandolini A, Hidalgo A (2015) Phenolic acids and antioxidant activity of wild, feral and domesticated diploid wheats. J Cereal Sci 64:168–175. https:// doi.org/10.1016/j.jcs.2015.05.005 Ziegler JU, Wahl S, Würschum T, Longin CFH, Carle R, Schweiggert RM (2015) Lutein and lutein esters in whole-grain flours made from 75 genotypes of 5 Triticum species grown at multiple sites. J Agric Food Chem 63:5061–5071. https://doi.org/10.1021/acs.jafc.5b01477

Appendix 1

439

2016 Beleggia R, Rau D, Laido G, Platani C, Nigro F, Fragasso M, Vita PD, Scossa F, Fernie AR, Nikoloski Z, Papa R (2016) Evolutionary metabolomics reveals domestication-associated changes in tetraploid wheat kernels. Mol Biol Evol 33:1740–1753. https://doi.org/10.1093/molbev/msw050 Dobre PS, Giura A, Cornea CP (2012) Protein content, thousand kernel weight (TKW) and volumetric mass (VM) variability in a set of wheat mutated and mutated/recombinant DH lines. Agro Life Sci J 5:59–62. ISSN-L 2285–5718 Górnaś P, Radenkovs V, Pugajeva I, Soliven A, Needs PW, Kroon PA (2015) Varied composition of tocochromanols in different types of bran: rye, wheat, oat, spelt, buckwheat, corn, and rice. Int J Food Prop 19:1757–1764. https://doi.org/10.108 0/10942912.2015.1107843 Masisi K, Beta T, Moghadasian MH (2016) Antioxidant properties of diverse cereal grains: a review on in vitro and in vivo studies. Food Chem 196:90–97. https:// doi.org/10.1016/j.foodchem.2015.09.021 Pahlavan A, Sharma GM, Pereira M, Williams KM (2016) Effects of grain species and cultivar, thermal processing, and enzymatic hydrolysis on gluten quantitation. Food Chem 208:264–271. https://doi.org/10.1016/j. foodchem.2016.03.092 Silvestro RD, Loreto AD, Bosi S, Bregola V, Marotti I, Benedettelli S, Segura-­ Carretero A, Dinelli G (2017) Environment and genotype effects on antioxidant properties of organically grown wheat varieties: a 3-year study. J Sci Food Agric 97:641–649. https://doi.org/10.1002/jsfa.7782 Xing W, Zhang H, Schecke KG, Liping L (2016) Heavy metal and metalloid concentrations in components of 25 wheat (Triticum aestivum) varieties in the vicinity of lead smelters in Henan province, China. Environ Monit Assess 188:23. https://doi.org/10.1007/s10661-015-5023-3 2017 Colasuonno P, Lozito ML, Marcotuli I, Nigro D, Giancaspro A, Mangini G, Vita PD, Mastrangelo AM, Pecchioni N, Houston K, Simeone R, Gadaleta A, Blanco A (2017) The carotenoid biosynthetic and catabolic genes in wheat and their association with yellow pigments. BMC Genomics 18:122. https://doi. org/10.1186/s12864-016-3395-622 Erik K, Knudsen B (2018) Microbial degradation of whole-grain complex carbohydrates and impact on short-chain fatty. 6:206–213. https://doi.org/10.3945/ an.114.007450.206 Fu B, Chiremba C, Pozniak C, Wang K, Nam S (2017) Total phenolic and yellow pigment contents and antioxidant activities of durum wheat milling fractions. Antioxidants 6:78. https://doi.org/10.3390/antiox6040078 Giordano D, Reyneri A, Blandino M, Locatelli M, Travaglia F, Bordiga M, Coïsson JD (2017) Bioactive compound and antioxidant activity distribution in roller-­ milled and pearled fractions of conventional and pigmented wheat varieties. Food Chem 233:483–491. https://doi.org/10.1016/j.foodchem.2017.04.065

440

Appendix 1

Hidalgo A, Fongaro L, Brandolini A (2017) Colour screening of whole-meal flours and discrimination of seven Triticum subspecies. J Cereal Sci 77:9–16. https:// doi.org/10.1016/j.jcs.2017.07.006 Hou J, Li T, Wang Y, Hao C, Liu H, Zhang X (2017) ADP-glucose pyrophosphorylase genes, associated with kernel weight, underwent selection during wheat domestication and breeding. Plant Biotechnol J 15:1533–1543. https://doi. org/10.1111/pbi.12735 Konopka I, Grabiński J, Skrajda M, Dąbrowski G, Tańska M, Podolska G (2017) Variation of wheat grain lipid fraction and its antioxidative status under the impact of delayed sowing. J Cereal Sci 76:56–63. https://doi.org/10.1016/j. jcs.2017.05.013 Laddomada B, Durante M, Mangini G, D’Amico L, Lenucci MS, Simeone R, Piarulli L, Mita G, Blanco A (2017) Genetic variation for phenolic acids concentration and composition in a tetraploid wheat (Triticum turgidum L.) collection. Genet Resour Crop Evol 64:587–597. https://doi.org/10.1007/ s10722-016-0386-z Pozniak CJ, Clarke JM (2017) CDC Precision durum wheat. Can J Plant Sci 97: 344–348. https://doi.org/10.4141/CJPS2012-160 Silvestro RD, Loreto AD, Bosi S, Bregola V, Marotti I, Benedettelli S, Segura-­ Carretero A, Dinelli G (2017) Environment and genotype effects on antioxidant properties of organically grown wheat varieties: a 3-year study. J Sci Food Agric 97:641–649. https://doi.org/10.1002/jsfa.7782 Spears JW, Lloyd KE, Krafka K (2017) Chromium concentrations in ruminant feed ingredients. J Dairy Sci 100:3584–3590. https://doi.org/10.3168/ jds.2016-12,153 Yilmaz VA, Koca AF (2017) Effect of different production techniques on bioactive compounds and antioxidant capacity of einkorn (Triticum monococcum L.) and durum (Triticum turgidum subsp. durum) bulgur. J Sci Food Agric 97:269–277. https://doi.org/10.1002/jsfa.7724 Zengin G, Nithiyanantham S, Sarikurkcu C, Uysal S, Ceylan R, Ramya KS, Maskovic P, Aktumsek A (2017) Identification of phenolic profiles, fatty acid compositions, antioxidant activities, and enzyme inhibition effects of seven wheat cultivars grown in Turkey: a phytochemical approach for their nutritional value. Int J Food Prop 20:2373–2382. https://doi.org/10.1080/10942912.2016.1 238391 2018 Boukid F, Vittadini E, Prandi B, Mattarozzi M, Marchini M, Sforza S, Sayar R, Seo YW, Yacoubi I, Mejri M (2018) Insights into a century of breeding of durum wheat in Tunisia: the properties of flours and starches isolated from landraces, old and modern genotypes. Lwt-Food Sci Technol 97:743–751. https://doi. org/10.1016/j.lwt.2018.08.014 Dinu M, Whittaker A, Pagliai G, Benedettelli S, Sofi F (2018) Ancient wheat species and human health: biochemical and clinical implications. J Nutr Biochem 52:1–9. https://doi.org/10.1016/j.jnutbio.2017.09.001

Appendix 1

441

Frakolaki G, Giannou V, Topakas E, Tzia C (2018) Chemical characterization and breadmaking potential of spelt versus wheat flour. J Cereal Sci 79:50–56. https:// doi.org/10.1016/j.jcs.2017.08.023 Fu BX, Wang K, Dupuis B, Taylor D, Nam S (2018) Kernel vitreousness and protein content: relationship, interaction and synergistic effects on durum wheat quality. J Cereal Sci 79:210–217. https://doi.org/10.1016/j.jcs.2017.09.003 Hefni ME, Schaller F, Witthoft CM (2018) Betaine, choline and folate content in different cereal genotypes. J Cereal Sci 80:72–79. https://doi.org/10.1016/j. jcs.2018.01.013 Jaskulska I, Jaskulski D, Gałȩzewski L, Knapowski T, Kozera W, Wacławowicz R (2018) Mineral composition and baking value of the winter wheat grain under varied environmental and agronomic conditions. Hindawi J Chem 2018:5013825. https://doi.org/10.1155/2018/5013825 Lachman J, Hejtmánková A, Orsák M, Popov M, Martinek P (2018) Tocotrienols and tocopherols in colored-grain wheat, tritordeum and barley. Food Chem 240:725–735. https://doi.org/10.1016/j.foodchem.2017.07.123 Liu L, Yang W, Cui SW, Jiang Z, Chen Q, Qian H, Wang L, Zhou S (2018) Effects of pentosanase and glucose oxidase on the composition, rheology and microstructure of whole-wheat dough. Food Hydrocoll 84:545–551. https://doi. org/10.1016/j.foodhyd.2018.06.034 Malalgoda M, Ohm JB, Meinhardt S, Simsek S (2018) Association between gluten protein composition and breadmaking quality characteristics in historical and modern spring wheat. Cereal Chem 95:226–238. https://doi.org/10.1002/ cche.10014 Paznocht L, Kotíková Z, Šulc M, Lachman J, Orsák M, Eliášová M, Martinek P (2018) Free and esterified carotenoids in pigmented wheat, tritordeum and barley grains. Food Chem 240:670–678. https://doi.org/10.1016/j. foodchem.2017.07.151 Philipp N, Weichert H, Bohra U, Weschke W, Schulthess AW, Weber H (2018) Grain number and grain yield distribution along the spike remain stable despite breeding for high yield in winter wheat. PLoS One 13:e0205452. https://doi. org/10.1371/journal.pone.0205452 Santis MAD, Giuliani MM, Giuzio L, Vita PD, Flagella Z (2018) Assessment of grain protein composition in old and modern Italian durum wheat genotypes. Ital J Agron 13:40–43. https://doi.org/10.4081/ija.2018.908 Savin T V., Abugaliyeva AI, Cakmak I, Kozhakhmetov K (2018) Mineral composition of wild relatives and introgressive forms in wheat selection. Vavilov J Genet Breed 22:88–96. https://doi.org/10.18699/vj18.335 Tian W, Li Y (2018) Phenolic acid composition and antioxidant activity of hard red winter wheat varieties. J Food Biochem 42:1–11. https://doi.org/10.1111/ jfbc.12682 Wollmer AC, Pitann B, Mühling KH (2018) Grain storage protein concentration and composition of winter wheat (Triticum aestivum L.) as affected by waterlogging events during stem elongation or ear emergence. J Cereal Sci 83:9–15. https:// doi.org/10.1016/j.jcs.2018.07.007

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Zhai Y, Wu Q, Chen G, Zhang H, Yin X, Chen F (2018) Broadcasting winter wheat can increase grain yield without reducing the kernels per spike and the kernel weight. Sustainability 10–4858. https://doi.org/10.3390/su10124858 Zhu F (2018) Triticale: nutritional composition and food uses. Food Chem 241:468– 479. https://doi.org/10.1016/j.foodchem.2017.09.009 2019 Coco LD, Laddomada B, Migoni D, Mita G, Simeone R, Fanizzi FP (2019) Variability and site dependence of grain mineral contents in tetraploid wheats. Sustainability 11–736. https://doi.org/10.3390/su11030736 Dangi P, Chaudhary N, Khatkar BS (2019) Rheological and microstructural characteristics of low molecular weight glutenin subunits of commercial wheats. Food Chem 297:124989. https://doi.org/10.1016/j.foodchem.2019.124989 Fares C, Menga V, Codianni P, Russo M, Perrone D, Suriano S, Savino M, Rascio A (2019) Phenolic acids variability and grain quality of organically and conventionally fertilised old wheats under a warm climate. J Sci Food Agric 99:4615– 4623. https://doi.org/10.1002/jsfa.9701 Malalgoda M, Ohm JB, Manthey FA, Elias EM, Simsek S (2019) Quality characteristics and protein composition of durum wheat cultivars released in the last 50 years. Cereal Chem 96:508–519. https://doi.org/10.1002/cche.10151 Tian W, Ehmke L, Miller R, Li Y (2019) Changes in bread quality, antioxidant activity, and phenolic acid composition of wheats during early-stage germination. J Food Sci 84:457–465. https://doi.org/10.1111/1750-3841.14463 Xue C, Matros A, Mock H-P, Mühling K-H (2019) Protein composition and baking quality of wheat flour as affected by split nitrogen application. Front Plant Sci 10:642. https://doi.org/10.3389/fpls.2019.00642 Zhong Y, Wang W, Huang X, Liu M, Hebelstrup KH, Yang D, Cai J, Wang X, Zhou Q, Cao W, Dai T, Jiang D (2019) Nitrogen topdressing timing modifies the gluten quality and grain hardness related protein levels as revealed by iTRAQ.  Food Chem 277:135–144. https://doi.org/10.1016/j.foodchem.2018.10.071

Appendix 2

References list for phytic acid concentrations in foods (Table 12.1) Chen Y, Chen J, Luo Z, Ma K, Chen X (2009) Synchronous fluorescence analysis of phytate in food. Microchim Acta 164:35–40. https://doi.org/10.1007/ s00604-008-0026-1 Febles CI, Arias A, Hardisson A, Rodríguez-Alvarez C, Sierra A (2002) Phytic acid level in wheat flours. J Cereal Sci 36:19–23. https://doi.org/10.1006/ jcrs.2001.0441 Feil B, Fossati D (1980) (1997) Crop quality and utilization: phytic acid in triticale grains as affected by cultivar and environment. Crop Sci 37:916–921. Hemalatha S, Platel K, Srinivasan K (2007) Zinc and iron contents and their bioaccessibility in cereals and pulses consumed in India. Food Chem 102:1328–1336. https://doi.org/10.1016/j.foodchem.2006.07.015 Hídvégi M, Lásztity R (2003) Phytic acid content of cereals and legumes and. Period Polytech Ser Chem 46:59–64. Joye IJ, Lagrain B, Delcour JA (2009) Use of chemical redox agents and exogenous enzymes to modify the protein network during breadmaking – a review. J Cereal Sci 50:11–21. https://doi.org/10.1016/j.jcs.2009.04.001 Khokhar S, Pushpanjali, Fenwick GR (1994) Phytate content of indian foods and intakes by vegetarian Indians of Hisar Region, Haryana State. J Agric Food Chem 42:2440–2444. https://doi.org/10.1021/jf00047a014 Lott JNA, Ockenden I, Raboy V, Batten GD (2000) Phytic acid and phosphorus in crop seeds and fruits: a global estimate. Seed Sci Res 10:11–33. Nitithan S (2004) Phytate and fiber content in thai fruits commonly consumed by diabetic patients. J Med Ass Thai 87:1444–1446. ttp://www.medassocthai.org/ journal Oatway L, Vasanthan T, Helm JH (2007) Phytic acid. Food Rev Inter 17:419–431. https://doi.org/10.1081/FRI-100108531 Owen RW, Weisgerber UM, Spiegelhalder B, Bartsch H (1996) Faecal phytic acid and its relation to other putative markers of risk for colorectal cancer. Gut 38:591–597. https://doi.org/10.1136/gut.38.4.591 © Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1

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Phillippy BQ, Bland JM, Evens T (2003) Ion chromatography of phytate in roots and tubers. J Agric Food Chem 51:350–353. https://doi.org/10.1021/jf025827m Schlemmer U, Frølich W, Prieto RM, Grases F (2009) Pytate in foods and significance for humans: food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food Res 53:330–375. https://doi.org/10.1002/ mnfr.200900099 Thavarajah P, Thavarajah D, Vandenberg A (2009) Low phytic acid lentils (Lens culinaris L.): a potential solution for increased micronutrient bioavailability. J Agric Food Chem 57:9044–9049. https://doi.org/10.1021/jf901636p Wu P, Tian J, Walker CEC, Wang F (2009) Determination of phytic acid in cereals – a brief review. 44:1671–1676. https://doi.org/10.1111/j.1365-2621.2009.01991.x

Definitions

A list of definitions for some categories related to the whole bread is gathered for the reader’s convenience. The most important list of definitions describes the documented morbidities, which are affected by the consumption of the whole bread. The definitions were adjusted to fit the text of this book. The contents of the definition topics 1. Selected list of bread types 2. The main cereals in human nutrition 3. Definitions of whole wheat 4. Wheat kernel organs 5. Wheat kernel ingredients 6. Digestible carbohydrates 7. The dietary fiber 8. The covering layer 9. Anti-oxidants and other minor compounds in the wheat kernel 10. Phytic acid 11. Amino acids and protein 12. Lipids 13. Carbohydrates 14. Vitamins 15. Methyl donors 16. Minerals 17. Anti-oxidant status 18. Milling 19. Baking 20. Chemical reactions related to baking

© Springer Nature Switzerland AG 2020 Y. Dror et al., Whole-Wheat Bread for Human Health, https://doi.org/10.1007/978-3-030-39823-1

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2 1. Morbidity and medical terms 22. Medical methodologies 23. The gut 24. A list of the mentioned lipids in human organs 25. Organizations

1. Selected List of Bread Types White Bread Made from refined wheat flour from which the bran and the germ layers have been removed. The milling process gives the white flour a longer shelf life by removing the unsaturated fat from the whole grain.

Whole Bread Whole bread prepared using whole flour that contains all parts of the cereal kernel. The bread prepared from flour that contains some amount of refined flour is also termed whole bread.

Baguette A long, thin loaf of French bread that is commonly made from basic lean dough

Bun A bread roll, sometimes sweet with many shapes and sizes

Sourdough bread Sourdough bread is made by the fermentation of dough using naturally occurring lactobacilli and yeast. It has a mildly sour taste not present in most bread made with baker’s yeast and better inherent keeping qualities than other bread due to the lactic acid produced by the lactobacilli (Wikipedia).

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447

Mantou Chinese steamed bread that is typically eaten as a staple food in northern parts of China where wheat, rather than rice, is consumed.

Roll Bread A small, often round loaf of bread served as a meal accompaniment (eaten plain or with butter). Commonly used to make sandwiches that are similar to those produced when using slices of bread. Found in most cuisines all over the world. Even in the same language, rolls are known by a variety of names.

Bagel Also spelled beigel, it is traditionally shaped by hand into a ring form from yeasted wheat dough, roughly hand-sized, that is first boiled for a short time in the water before baking. The result is a dense, chewy, doughy interior with a browned and sometimes crisp exterior. It is a popular bread product in North America.

Flatbread Many types produced leavened, slightly leavened, and unleavened. The product is made with flour, water, and salt and then rolled into flattened dough. Many flatbreads are unleavened, although some are slightly leavened, such as pita bread. Some examples are listed below: Chapati A typical unleavened wheat staple food predominates in a round disk of ~150 mm, generally prepared from whole wheat Focaccia A flat oven-baked Italian staple bread, similar in style and texture to pizza doughs Naan A leavened, oven-baked flatbread found in the Middle East, Central, and South Asia Pita A typical unleavened wheat staple food in the Mediterranean, similar to the chapati. The high baking temperature inflates the dough that can open it into two halves. Tortilla A type of thin, unleavened flatbread, made from corn or wheat. In Spanish, “tortilla” means “small cake.”

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Definitions

Ready-to-Eat Cereals (RTEC) Ready-to-eat cereals are staple food most popular in many Western countries. These are traditional breakfast food made from processed cereal grains, many made with high sugar content, which are suitable for human consumption without further cooking required.

2. The Main Cereals in Human Nutrition Species A species is a basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. It is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction (Wikipedia).

Poaceae Poaceae is a large family of monocotyledonous flowering plants with ~780 genera and ~12 k species. It is the most economically important plant family, providing staple grain foods such as barley, corn, millet, rice, rye, oat, sorghum, teff, and wheat. It also includes bamboo. Gramineae is also reckoned to denote the Poaceae family but with much lower frequency (Web of Science).

Staple Food A food that is eaten routinely and in such quantities that it constitutes a dominant portion of a diet for a given people. The main global staples for humans with approximate decreasing order of energy intake are rice, wheat, corn (maize), potato, cassava, soybean, sweet potato, yams, sorghum, and plantain (banana cultivar which is generally cooked). Some of the crops mainly feed animal husbandry. Some are wet products with low-energy content.

Rice Paddy Rice paddy comprises ~28% of the global production of the main cereal crops and ~50% of the main crops used solely for human nutrition. Only tiny part of the rice is consumed as unrefined products.

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Wheat Wheat is domesticated in the Fertile Crescent in ancient times. Presently, the first known use of wheat goes back 23 kya (see The early exploration). It is known to have used in the Middle East and Ancient Greece and mentioned in the Old Testament literature. At present, two major types of wheat rule the market: bread wheat (soft wheat), which comprises the vast majority of the market and is used for bread, rolls, flatbread, and cookies, and durum wheat (hard wheat), which is used mainly for pasta products. Each type might be consumed as refined or whole-wheat products. Moreover, nowadays, refined products control the market. It comprises ~26% of the global grain production and ~47% of the main crops used solely for human nutrition (2016) (FAOStat).

Durum Durum wheat (Triticum durum Desf.) is a cold-sensitive, tetraploid species of wheat, better adapted to the warm climate. It is the second most cultivated species of wheat after bread wheat (Triticum aestivum L.). While bread wheat is used in most wheatbased food production (bread, cookies, etc.), durum wheat is utilized for the manufacturing and production of pasta in the Middle East and the Mediterranean (with ~60% of the global production), North Africa, the former USSR, the North American Great Plains, India, and Europe, as well as for diverse food products (Lidon et al. 2014). The durum production comprises ~8% of the global production with ~ 30 M ton annually. Their kernels are usually large, golden amber, and translucent and the hardiest of all varieties. The combination of the high color concentration in the durum wheat with the specific highly nutritional compounds has contributed to the development of functional food for improved nutritional and health qualities (Ficco et al. 2014). Except for bread wheat and durum wheat, some other types are cropped at comparatively lower scales. Some of these types are presented below:

Farro Farro is a term for a group of three wheat species, spelt, emmer, and einkorn, which are hulled wheat types.

Spelt Spelt is a wheat species cultivated since 7 thousand years ago and was an important variety at the medieval era and at the Bronze Age. Presently, it is only commonly grown in Europe. Because of its lower requirement for fertilizers, it becomes popular in organic farming. It is not a gluten-free grain.

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Definitions

Emmer Emmer is one of the first wheat crops domesticated in the Near East and is widely cultivated in ancient times, but now, it is a surviving remnant crop in mountainous regions of Europe and Asia. It is hulled wheat with strong glumes that enclose the grains.

Einkorn Einkorn refers to the wild wheat species or to domesticated cultivations. It is a diploid species of hulled wheat, with tough glumes that tightly enclose the grain, and is one of the first plants to be domesticated and cultivated dated 8.3 thousand years ago.

Kamut Kamut, a Khorasan or an Oriental wheat (commercially known as Kamut), is an ancient grain type and a tetraploid wheat species.

Bulgur Bulgur is commonly made of durum groats of the whole wheat though other wheat species can be used. Its product is usually boiled similar to rice or other grains, but it can also be fried, roasted, baked, or simply soaked. Since bulgur is already partially cooked, it takes less time to prepare than other whole grains and has a longer shelf life. It remains an important ingredient in Middle Eastern cuisine and is also common in India and the Balkan states. It is the main ingredient in tabbouleh (a salad of bulgur, tomatoes, onions, and herbs) and kibbeh (ground meat patties with onions and spices). Since the early 1900s, bulgur has grown in popularity as a health and gourmet food in the United States and Western Europe. Traditionally, bulgur is prepared by partially boiling whole-wheat groats until they crack, drying them in the sun and then grinding them to various sizes in a stone mill. Industrially prepared bulgur is parboiled, then oven-dried, and ground and sifted mechanically to precise grades.

Rye Rye grain is used for bread, beer, crispbread, some whiskeys, and vodkas. Unlike wheat gluten, rye proteins do not form a continuous gluten network in bread. Instead, arabinoxylan contributes to the formation of its structure (Jonsson et  al.

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2018). Many claims suggest a superior health benefit of the rye bread upon wheat bread. Such claims have not denied; however, no comprehensive studies are available for the comparison between the whole rye bread and the whole-wheat bread. Most of the comparison studies evaluated the refined wheat bread versus the whole rye bread. Rye comprises 0.4% of the total global grain production. In some of the European countries, noticeable amounts of rye production are observed in top 12 countries for the 2016 production, with percentage of wheat production as follows: Luxembourg 6, Latvia 7, Norway 7, Estonia 7, Austria 10, Finland 11, Germany 13, Denmark 14, Montenegro 17, Portugal 17, Poland 20, and Belarus 28.

Triticale Triticale is a hybrid of wheat and rye that combines the yield potential and the quality of wheat with the disease and environmental tolerance of rye. It comprises 0.5% of the total grain production.

Oats Oats are considered as an appropriate wheat substitute for patients with celiac disease, but there is a debate regarding the safety of such substitution for these individuals. These comprise 0.4% of the total grain production.

Buckwheat Buckwheat is a group of pseudocereals (genus Fagopyrum and Polygonaceae) with two major species with agricultural significance. It is a gluten-free product that comprises 0.4% of the global grain production.

Corn (Maize) Corn is a unique plant species that belongs to the Poaceae family, having male and female flowers. It is a staple food in Latin America, Africa, and Asia, has a low protein quality because of the lower content of lysine and tryptophan, and has a considerable effect on low-income families in many of the developing countries where corn is a staple food. It is the leading global cereal crop followed by rice and wheat.

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Definitions

Sorghum Sorghum is extremely important in Asia, Africa, and other semiarid regions where it is mainly used for human consumption. In Western countries, it is primarily used for animal feeding (Cardoso et al. 2017) which comprises ~0.4% of the global grain production.

Pseudocereals Pseudocereals are crop cultivars that do not belong to the Poaceae family with edible grains mainly ground for flour such as amaranth, breadnut, buckwheat, chia, cockscomb, pitseed, goosefoot, qañiwa, quinoa, and wattleseed.

3. Definitions of Whole Grain The industry round table: Whole wheat is a whole-grain food that provides ≥8 g whole-grains/30 g (27/100 g) but does not contain excessive amounts of fat, sugar, sodium, or energy (Ferruzzi et al. 2014). AACC International (American Association of Cereal Chemists International): Whole grain is defined as the intact, ground, cracked, or flaked caryopsis (naked cereal kernel), the principal anatomical components of which starchy endosperm, germ, and bran are present in the same proportions as in the intact caryopsis. A recent definition follows the same principle, but some are broader and more commodity-based, including the grains with similar end uses, while others are more restricted. Currently, no common internationally accepted definition exists. Therefore, exact definitions of the whole grain and whole-grain foods processed in various ways, and knowledge about the components providing health effects in food as consumed, are crucial issues for the whole-grain research and recommendations (Andersson et al.2014). The Whole-Grains Council: Whole grains or its food products contain all the essential parts and the naturally occurring nutrients of the entire grain seed in their original proportions. If the grain has been processed (e.g., cracked, crushed, rolled, extruded, and/or cooked), the food product should deliver the same rich balance of nutrients that are found in the original grain seed. The following are examples of whole grains: amaranth, barley, buckwheat, corn (including whole cornmeal and popcorn), millet, oats (including oatmeal), quinoa, rice (both brown rice and colored rice), rye, sorghum (also called milo), teff, triticale, wheat (including varieties such as spelt, emmer, farro, einkorn, kamut, durum, and forms such as bulgur, cracked wheat, and wheat berries), and wild rice.

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The European Union: There is no legally endorsed definition of whole grain and whole-grain products and foods at the European level. Denmark and Sweden: For a food to be characterized as whole grain, it is required to consist of at least 50% of dry matter from whole-grain ingredients. The Netherlands: 100% of the flour must be whole grain for bread to be labeled as 100% whole grain. Germany: Whole-grain bread must be at least 90% whole grain. The United Kingdom: Whole-grain foods must contain ≥51% whole-grain ingredients by weight (EU Science Hub). FDA Whole-Grain Health Claim: Foods must be >51% whole grain by weight per reference amount customarily consumed. The dietary fiber is used as a marker for compliance but may be waived on single-ingredient whole-grain foods (e.g., brown rice). With the time being of intensive pursuing of the public for high intake of whole grain, such definition is most important to know which food may fulfill the whole-grain function (Korczak et al. 2016). For the whole-wheat flour, the marked differences between the tissues have nothing to affect the final product. However, flour refining markedly affects the high differences between the tissues. Even the withdrawal of one tissue alone might result in the main reduction of a specific ­compound in the whole flour. Breeding of wheat variety for a higher content of a specific compound should evaluate the tissue distribution of all minor or micro-compounds.

4. Wheat Kernel Organs Caryopsis Caryopsis, also called grain, is a specialized type of small, dry, one-seeded indehiscent fruit (as wheat) in which the fruit and seed fuse in a single grain.

Indehiscent Fruit Fruit that does not open at maturity in a predefined way but relies on predation or decomposition to release the seeds.

Bran Also known as miller’s bran is the hard outer layers of the cereal grain. It consists of combined aleurone and pericarp.

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Definitions

Embryo The embryo arises from the fusion of the male and the female gametes. It is the most important grain component for the survival of the species as it is capable of developing into a plant of the filial generation.

Endosperm Endosperm consists of three tissues, starchy endosperm, sub-aleurone cells, and aleurone.

Starchy Endosperm The endosperm cells contain the outer layer of the sub-aleurone cells that are “prismatic,” while the “central” cells are more variable in shape.

Crease Crease is the deep groove in the wheat kernel on its flat side. In wheat, most of the assimilates and mineral ions incorporated into the endosperm during the grain-­ filling process move along the vascular strand of the pericarp and across the tissues of the crease into the endosperm cavity (Cochrane 1983).

Hyaline Layer Hyaline layer or perisperm, a layer outside the aleurone layer, is the inner layer of the grain coat (envelop).

Trichomes Trichomes are highly specialized epidermal cells implicated in several functions, such as transpiration, freezing tolerance, protection against pests, and UV light.

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455

Amyloplasts Amyloplasts are a type of plastids, double-enveloped organelles in plant cells that store and synthesize starch for the plant through the polymerization of glucose.

Aleurone Aleurone is a single cell layer at the inner side of the bran. It contains most of the minerals, vitamins, phenolic anti-oxidants, and lignans of the wheat grain.

Sub-Aleurone Cells (layer) Two to three outer cell layers of the starchy endosperm (below the aleurone layer) contain a very high gluten concentration.

Nucellus The kernel tissue degenerates by the process of programmed cell death (apoptosis) during the early stages of wheat grain development.

Testa Testa is a tough, hard, outer coat that protects the seed from fungi, bacteria, and insects.

Spermoderm The seed covering that is sometimes limited to the outer coat or the testa.

Pericarp Pericarp is the tissue of the caryopsis lying outside the seed coats that originate as components of the carpel wall.

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Definitions

Nucellar Epidermis One of the outer layers of the kernel endosperm.

Carpel Wall The female reproductive part of the flower. The fertilization of the egg within the carpel by the pollen grain results in the seed development within the carpel.

Chaff The dry, scaly protective casings of the cereal grain.

Radicle The first part of a seedling to emerge from the seed during the process of germination.

Scutellum The shield-like cotyledon of wheat, barley, and rice seed which is a modified seed leaf.

Tube Cell One of the two cells produced by the division of the microspore nucleus in the male gametophyte development in the higher plants and that functions in the development of the pollen tube.

Chromoplast Heterogeneous organelles responsible for pigment synthesis and storage.

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457

Plastid A major double-membrane organelle found in the cell plant. It is the site of synthesis and storage of compounds used by the cell, like starch fatty acid, and pigments.

Spherosome A spherical organelle that is present in plant cells with up to 1 mm long. It synthesizes and stores lipids and is bounded by a single membrane.

Microfibrils Microfibrils are very fine fiber-like strand, consisting of glycoproteins and cellulose. These are the main structural unit in the formation of the secondary and primary walls of the plant fibers.

5. Wheat Kernel Ingredients Nutritional Classification of the Main Wheat Kernel Ingredients (a) Digestible carbohydrates (b) Fermentable carbohydrates, such as cellulose and pectin (c) Non-fermentable carbohydrates, such as lignin (d) Proteins, such as gluten (e) Lipids (f) Major minerals, such as calcium (g) Microelements and vitamins (h) Bioactive ingredients, mainly tocols, carotenes, sterols, and phenols, yellow pigments, and methyl donors (i) Phytic acid Except for the ingredients that are defined and considered as bioactive ingredients, some other compounds are also acting as bioactive compounds while some of the carbohydrate and some of the proteins acting as anti-oxidants. Some of the ingredients defined herewith are present only in small amounts in the whole flour content. Therefore, they are not listed in kernel composition (Tables 5.2, 5.4, 5.5, 6.1, 6.2, 8.1, 8.2, and 9.3). However, some of these ingredients might have particular qualities. For the breeding of the newer varieties with higher nutritional quality for the whole-wheat consumption, detailed knowledge should be gathered for nutritional qualities of all the ingredients.

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6. Digestible Carbohydrates Free Sugars Free sugars are kernel monosaccharides not bound to other compounds. In comparison with other cereals, wheat kernel contains only a small amount of these fractions.

Hexoses Hexoses are monosaccharides with six carbon atoms, with the general formula of C6H12O6. These are classified by functional group, with aldohexoses, such as glucose, galactose, and mannose, and ketohexoses, such as fructose.

Glucans A polysaccharide derived from D-glucose with two main types: α-Glucans, glucose monomers linked by α-glycosidic bonds such as dextran, glycogen, and starch (a mixture of amylose and amylopectin) β-Glucans, glucose monomers linked by β-glycosidic bonds such as cellulose

Pentosan Pentosan is any of various polysaccharides that on hydrolysis yield only pentoses and occur widely in plants and is a polymer composed of pentoses. They can have an influence on bread quality.

Pentose A monosaccharide with five carbon atoms. It is organized into two groups: aldopentoses with an aldehyde functional group at position 1 and ketopentoses with a ketone functional group at position 2 or 3. Typical pentoses are arabinose, xylose, and ribose (Figs. 7.1 and 7.2).

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D-Glucose Glucose is a hexose with an aldehyde group. It can exist in an open-chain (acyclic) and ring (cyclic) form. In water solution, both forms are in equilibrium, and at pH 7, the cyclic one is predominant. Glucose is a primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state (Fig. 6.1). L-Glucose does not occur naturally in higher living organisms but can be synthesized in the laboratory.

Galactose An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins (Fig. 6.5).

Maltose Maltose is a disaccharide composed of two D-glucose and the basic molecule of starch. It has a minor role in food but accumulates in large amounts in the body during the digestion of starch. The enzyme β-amylase cleaves starch to maltose units (Fig. 6.4).

Maltotriose (Amylotriose) Maltotriose is a common oligosaccharide metabolite found in human urine after maltose ingestion and is composed of a trisaccharide consisting of three glucose molecules (Fig. 6.4).

Starch Starch is mainly made up of two polymers of D-glucose: the lightly branched amylose with a small number of long glucan chains and the highly branched amylopectin, which contains many clusters of short chains.

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Definitions

Resistant Starch Resistant starch is the sum of starch and products of starch degradation that are not absorbed in the small intestine.

Amylopectin A highly branched polymer of the glucose (Fig. 6.3).

Amylose Amylose is a linear molecule of (1→4) linked α-D-glucopyranosyl units, but now, it is well established that some molecules are slightly branched by (1→6)-alpha-­ linkages. When degraded by pure β-amylase, linear macromolecules are completely converted into maltose, whereas branched chains give also one β-limit dextrin consisting of the remaining inner core polysaccharide structure with its outer chains recessed. Starches of different botanical origins possess different granular sizes, morphology, polymorphism, and enzyme digestibility. These characteristics are related to the chemical structures of the amylopectin and amylose and how they are arranged in the starch granule (HMDB) (Fig. 6.2).

Glycocalyx The pericellular matrix which is a glycoprotein and glycolipid covering that surrounds the cell membranes of some bacteria, epithelia, and other cells.

Arabinose An aldopentose monosaccharide that contains five carbon atoms, including an aldehyde (CHO) functional group (Fig. 7.1).

Arabinoxylans Arabinoxylans comprise the hemicellulose found in the primary and secondary cell walls of plants.

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Fructan Fructan is a polymer of fructose.

Galactan Galactan is a galactose polymer. Galactans and galactan-containing polysaccharides are found mainly in gum, pectic substances, hemicellulose, and other complicated polymers. Arabinogalactans are common galactan-containing polysaccharides (Arifkhodzhaev 2000).

Arabinan L-Arabinan is a polymer of L-arabinose, which is found in nature wherever pectic substances occur. Arabinan is a straight-chain polymer of L-arabinofuranose units derived from L-arabinan (Tagawa and Kaji 1988).

Non-Starch Polysaccharides A range of non-starch polysaccharides with 32–137 mg/g dry matter content are observed in a survey of 210 wheat lines (Pritchard et al. 2011). In the wheat kernel, the main ingredients of the non-starch polysaccharides are arabinoxylans, arabinogalactans, and β-glucan.

Arabinoxylan Arabinoxylan chains contain a large number of 1,4-linked xylose units. Many xylose units are substituted with 2, 3, or 2,3-linked arabinose residues (Wikipedia).

Hemicelluloses (Polyose) Hemicellulose is a heteropolymer (of polysaccharides) with a random and amorphous structure with little strength.

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Heteroxylans Heteroxylan is a form of xylan in which some of the xylose residues are replaced by the glucuronic acid. These are the core noncellulosic wall polysaccharides of the grain. The major noncellulosic components of endosperm walls are usually heteroxylans and with lower levels of xyloglucans, glucomannans, and pectic polysaccharides (Burton and Fincher 2014).

Mannan Mannan is a plant polysaccharide that is a linear polymer of the sugar mannose.

Glucomannans Glucomannans are linear copolymers of β-d-glucopyranose (∼30%) and its 2-­epimer, β-d-mannopyranose (∼70%), joined by (1 → 4)-linkages to form linear chains with 3000 Da. Some tannins can have molecular weights of >30 k. Their characteristic features are their chemical identity reaction for phenols and their capacity for precipitating proteins (Serrano et al. 2009). (Fig. 9.14).

Flavonoids Flavonoids, a type of polyphenols with the general structure of a 15-carbon skeleton, which consists of two phenyl rings and a heterocyclic ring, are a group of plant metabolites thought to provide health benefits through cell signaling pathways and anti-oxidant effects. The total flavonoid content of wheat kernel is 470 μg/g (Fig. 9.15).

Anthocyanins/Anthocyans Anthocyanins/anthocyans are polyphenol compounds with glycoside moieties (Fig. 9.16).

Lignans Lignans, described as macromolecules with two units of phenylpropanoid that coupled together, are plant products of low molecular weight formed primarily from oxidative coupling of two p-propylphenol moieties. Whole-wheat lignan content ranges from 6 to 37 μg/g (Figs. 9.18 and 9.19).

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Enterolactone and Enterodiol These compounds are mammalian lignans or enterolignans cleaved from the lignans and are absorbed into the bloodstream with anticarcinogenic activity. In the bloodstream, they undergo enterohepatic circulation (Fig. 9.19).

Stilbene Stilbene is a polyphenol found in low quantities in the human diet.

Coumarin Coumarin is a natural substance found in many plants with an aromatic structure of the class of benzopyrone chemical.

Proanthocyanidins Proanthocyanidins are abundant polyphenols in the human diet with polymeric structure and high molecular weight and with limited gut absorption.

Terpene Terpene is a large and diverse class of compounds derived from units of isopentenyl pyrophosphate. They are the major building blocks for the biosynthesis of the steroids.

Isoprenoid Isoprenoid is a class of compounds composed of ≥2 hydrocarbons units, with each unit consisting of five carbons called isoprene.

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Polyene Polyenes are poly-unsaturated compounds that contain ≥3 alternating double and single carbon-carbon bonds. These carbon-carbon double bonds interact in a process known as conjugation. Dienes are related to polyenes with two alternating double and single bonds.

Sterols Sterols, also known as steroid alcohols which are the subgroup of steroids, occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol. It has a molecular weight of 248 Da with a high wheat kernel content of ~640 μg/g (Fig. 9.1).

Stanols Stanols are present in small amount in the human diet. It has a moderate wheat kernel content of ~200 μg/g and has many similar structures (Fig. 9.3). Whole-grain foods, mostly wheat, and rye are the main dietary source.

10. Phytic Acid Phytic acid, also known as myoinositol hexakisphosphate, has an anti-oxidant effect with an average molecular weight of 660 Da. It has a high wheat kernel content of ~10000 μg/g. It acquired the fame of anti-nutrients because of its ability to chelate the divalent cations (Fig. 12.1).

Inositol Inositol (myoinositol) is a carbocyclic sugar that is abundant in the brain and in other mammalian tissues that mediates cell signal transduction. On phosphorylation, inositol became phytic acid. It might have an anti-malignant activity (Kapral et al. 2012) (Fig. 12.1).

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11. Amino Acids and Protein Amino Acids All proteins consist of long chains of α-amino acids which have L-configuration of the α-carbon atom. These amino acids and other L-amino acids participating in many metabolic cycles and some of the amino acids are precursors for essential metabolites.

Essential (Indispensable) Amino Acid Essential (indispensable) amino acids cannot be synthesized by organisms and hence must be derived from food. For humans, the nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. In the last years, the term indispensable has introduced.

EAAI The essential amino acid index defines the quality of the protein content of the indispensable amino acids.

Lysine Lysine is an indispensable amino acid which has a particularly low content in wheat proteins (Table 5.2).

Methionine Methionine is an indispensable amino acid with the lowest content in wheat proteins (somewhat higher nutritional value than lysine), which are reported to have a low methionine score (Table 5.2).

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Phenylalanine Phenylalanine is an essential amino acid (Fig. 9.5).

Protein Protein is composed chain/chains of amino acids in a specific order of any of the various naturally occurring extremely complex substances of large molecules that consist of amino acid residues joined by the peptide bonds. Every protein has a unique amino acid sequence dictated by the nucleotide sequence of its gen. Proteins perform all the catalytic activities in all cells and in the wheat kernel (and other seeds) and exist also as storage compounds that some of them have particular biologic activities and some consist of particular technological qualities. Wheat kernel contains many storage proteins that have biological activities. Some of the proteins have a unique quality that enables the bread proofing in the baking process. Crude protein Total proteins of the kernel either digested or excreted Digested protein The protein that decomposed into individual amino acid which readily absorbed into the portal blood

Wheat Kernel Proteins These are grouped into two major families: (a) Salt- and alcohol-soluble (globulins and prolamins, respectively), e.g., gliadins and glutenins (b) water-soluble non-prolamins, e.g., albumins and globulins Gluten Gluten is the natural protein found in wheat and some other Poaceae species and presumably supplies the highest protein mass for human nutrition mainly in wheat, rice, and corn than in any other single protein in human nutrition. It is a complex mixture of prolamin and glutelin proteins and has a particular role in the construction of the wheat kernel with an extremely high protein concentration (45%) in the sub-aleurone cells of the starchy endosperm (Shewry 2019). Vital gluten Vital gluten is an isolated gluten powder that by mixing with water can be rapidly hydrated and recover its viscoelastic properties (elasticity and extensibility), due to gliadins and glutenins, which form the gluten network. A

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small amount added to yeast bread recipes improves the texture and the elasticity of the dough. Vital wheat gluten can also be used to make a vegetarian meat substitute known as seitan. It provides extra gluten needed for whole-­ grain loaf to raise their highest. It is particularly helpful in loaves that use low-gluten or whole-grain flours, such as rye, oat, teff, spelt, or buckwheat. Friabilin Friabilin is a 15 kDa water-washed starch granule protein linked with kernel hardness. It is mostly linked with the starch of soft wheat, rarely associated with the starch of hard wheat and completely absent from durum starch. Puroindolines Puroindoline genes (Pina and Pinb) control the grain texture or hardness in wheat. The wild-type/soft alleles lead to softer grain, while a mutation in one or both of these genes results in a hard grain. The ratio of Pina/Pinb expression was generally lower in the hard nonmutant genotypes. Hardness may be associated with differences in Pin expression and other factors and is not simply associated with mutations in the PIN protein coding sequences (Nirmal et al. 2016). Gliadins Gliadins are a type of prolamin which is a class of wheat proteins present in the genus Triticum. Glutenin Glutenin is high-molecular-weight seed storage proteins of wheat endosperm. Wheat globulin Wheat globulin, found at the range of 300 kDa, is generally less abundant in the range of 180 kDa. Prolamins Storage proteins having a high content of proline and glutamine and found in the cereal grains (HMDB). Secalin Secalin is a prolamin glycoprotein found in the grain rye and one of the gluten proteins that people with coeliac disease cannot tolerate. Thus, rye should be avoided by people with celiac disease. In bread making with rye flour, this protein requires exposure to an acid such as lactic acid to make the bread rise (Wikipedia). Hordein Hordein is a prolamin glycoprotein, present in barley and some other cereals, together with gliadin and other glycoproteins (such as glutelins) coming under the general name of gluten. Avenins Avenins are prolamin proteins found in oat that cause gluten sensitivity. These make up 10-15% of the total oat protein, in contrast to wheat, in which prolamins make up 80% of the total protein content.

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Lectin Lectin is a carbohydrate-binding protein that is highly specific for the sugar moieties of other molecules. It performs recognition on the cellular and molecular level and plays numerous roles in biological recognition phenomena. Lectins are ubiquitous in nature and found in many foods. Some foods such as beans and grains need to be cooked or fermented to reduce lectin activity.

Wheat Germ Agglutinin (WGA) Wheat germ agglutinin (WGA) is a lectin with four binding sites specific for N-acetyl-D-glucosamine and N-acetyl-D-neuraminic acid residues. The wheat kernel contains ~230 μg/g.

Oleosin Oleosin is a protein that covers the oleosome which is a spherical intracellular organelle that stores fatty oils in the plant. Some or all of the oleosins are enzymes and acquire catalytic activities.

Amylase-Trypsin Inhibitors Amylase-trypsin inhibitors could be involved in insect defense mechanisms. These have five disulfide bonds, which are essential for the inhibitory activity, and have immune reactions to wheat ingestion, such as celiac disease, wheat allergy, and non-­ celiac gluten/wheat sensitivity (UNIPROT).

Interferon Interferon is a group of signaling proteins found in animals that made and released by the host cells in response to the presence of several pathogens.

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12. Lipids Lipids are a biomolecule that is soluble in nonpolar solvents which are typically hydrocarbons used to dissolve other naturally occurring hydrocarbon lipid molecules that do not dissolve in water.

Fat Fat consists primarily of carbon and hydrogen atoms; thus, they are hydrocarbon molecules such as cholesterol, phospholipids, and triglycerides. The terms “lipid,” “oil,” and “fat” are often confusing. Lipid is the general term, though a lipid is not necessarily a triglyceride. Oil normally refers to a lipid with short or unsaturated fatty acid chains that is liquid at room temperature. Fat with the highest energetic density is one of the three main macronutrients, along with the other two carbohydrates and protein. It has the highest energetic density.

Fatty Acids Fatty acids are carboxylic acids with an aliphatic chain, saturated or unsaturated. Some of the naturally occurring fatty acids have a branched chain of an even number of carbon atoms, from 2 to 28. It is composed of three main classes of esters: triglycerides, phospholipids, and cholesterol esters. In any of these forms, fatty acids are both important dietary sources of fuel for animals and they are the main structural components of the cellular membranes. Wheat kernel has four main groups of fatty acids as follows: Saturated designated such as 14:0, 16:0, and 18:0 Monounsaturated designated such as 18:1 and 20:1 Polyunsaturated designated such as 18:2 and 18:3, which are essential fatty acids present at a considerable lower content in refined wheat flour versus whole-­ wheat flour The seed unsaturated fatty acids are the most sensitive storage material for the oxidation attack by the free radicals that are moderated by high accumulation of anti-oxidant

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Short-Chain Fatty Acid (SCFA) Short-chain fatty acids (SCFA) are fatty acids with up to six carbon atoms. These are produced in the colon by bacterial fermentation of dietary fiber.

Essential Fatty Acids (EFAs) There are only two known essential fatty acids for humans: α-linolenic acid (a ω-3 fatty acid) and γ-linolenic acid (a ω-6 fatty acid). Human and other mammals lack the ability to introduce double bonds in the fatty acids beyond carbon 9 and 10; hence, ω-6 linoleic acid (18:2,9,12), abbreviated 18:2n-6, and ω-3 linolenic acid (18:3,9,12,15), abbreviated 18:3n-3, are essential for humans in the diet.

Unsaturated Fatty Acids Fatty acids that contain at least one double bond within the chain.

Omega−3 Fatty Acids Omega-3 fatty acids, also ω−3 fatty acids or n−3 fatty acids, are polyunsaturated fatty acids (PUFAs) with a double bond three atoms away from the terminal methyl group. They are widely distributed in nature, being important constituents of animal lipid metabolism, and play an important role in the human diet and in human physiology. Three types of omega−3 fatty acids are involved in human physiology, namely, α-linolenic acid (ALA), found in plant oils, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both commonly found in marine oils (Wikipedia).

Linoleic Acid (C 18:2) Linoleic acid is a polyunsaturated essential fatty acid found mostly in plant oils. It is an omega-6 fatty acid with two cis-double bonds at positions 9 and 12 (Fig. 5.1) used in the biosynthesis of prostaglandins and cell membranes.

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Linolenic (C 18:3) Linolenic is a polyunsaturated essential omega-6 fatty acid with three cis-double bonds at positions 9, 12, and 15. It is highly concentrated in certain plant oils and has reported to inhibit the prostaglandin synthesis (Fig. 5.2).

Polar Lipids The presence of the phosphoryl group results in a molecule with a polar head. Membrane lipids are polar and separated into phospholipids and glycolipids. While most lipids are composed of nonpolar hydrocarbon structures, other lipids can contain positively and/or negatively charged elements, the nature of which imparts particular physical properties that give charged lipids structural and functional versatility.

Nonpolar Lipids Are not dissolved in polar solvents such as the typical lipids of triacylglycerides.

Lysolipid The common term “lyso,” denoting the position lacking a radyl group in glycerolipids and glycerophospholipids, will not be used in systematic names but will be included as a synonym (Fahy et al. 2011).

Lysophosphatidylethanolamine Lysophosphatidylethanolamine is a type of chemical compound derived from a phosphatidylethanolamine, which is typical of cell membranes.

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13. Oligocarbohydrates  ODMAPs (Fermentable Oligo-, Di-, and Monosaccharides F and Polyols) FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols) are short-­ chain carbohydrates that are poorly absorbed in the small intestine. They include short-chain oligosaccharide polymers of fructans and galactooligosaccharides, disaccharides, monosaccharides, and sugar alcohols such as sorbitol, mannitol, xylitol, and maltitol. FODMAPs are naturally present in food and the human diet.

Acarbose Acarbose is an antidiabetic drug used to treat type 2 diabetes mellitus. It is in limited use in the United State because it is not potent enough to justify its side effects like diarrhea and flatulence. It inhibits the enzyme α-glucosidase that releases glucose from larger carbohydrates.

Fructooligosaccharides Fructooligosaccharides (FOS) or oligofructose or oligofructan is used as an alternative sweetener with 30–50% sweet of sucrose (Fig. 7.12).

Glycosaminoglycans or Mucopolysaccharides Glycosaminoglycans or mucopolysaccharides are long unbranched polysaccharides consisting of a repeating disaccharide unit. The repeating unit consists of an amino sugar (N-acetylglucosamine or N-acetylgalactosamine) along with a uronic sugar (glucuronic acid or iduronic acid) or galactose. These proteins are highly polar and attract water and therefore useful to the body as a lubricant or as a shock absorber.

Mucoprotein Mucoprotein is a glycoprotein composed primarily of mucopolysaccharides.

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Glycoprotein Glycoprotein is a protein which contains oligosaccharide chains (glycans) covalently attached to amino acid side chains.

14. Vitamins Vitamins are organic ingredient that for optimal growth or well-being, the organism must acquire from food because the metabolic system cannot synthesize at an adequate scale. The vitamin term refers to a specific organism such as vitamin C for the human. Vitamin C is synthesized by the majority of the animals. The following are the list of vitamins humans need (with the descending order of the weight requirement): vitamin C (ascorbic acid), niacin B3, tocopherol E, pantothenic acid B5, vitamin B6 (PLP), thiamine B1, riboflavin B2, pyridoxine B6, retinol A, folic acid B9, menadione K, biotin (B7, H), and B12. However, the definition of vitamin has not been revised within the last generations and within the major advances in the health sciences. Even the consensual optimal intakes are based on the inaccurate old system of observations that misleads people’s preferences in consuming vitamins.

Conditional Vitamin Conditional vitamin is an ingredient that an organism must acquire from food in addition to the endogenic synthesis because his metabolic system cannot synthesize adequately for an optimal growth/well-being/longevity, such as choline (Gao et al. 2016).

Chromanol Rings Chromanol rings are a class of bicyclic heterocycles formed by ring closure from substituted quinones. It is the basic rings of the tocopherols.

Tocols Bioactive compounds with anti-oxidant traits, they prevent oxidation of the double bonds by reacting with the peroxyl radicals and protecting the lipids and the membrane proteins against the oxidative stress. Vitamin E is a tocol.

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Tocotrienols Tocotrienols possess powerful neuroprotective, anti-oxidant, anticancer, and cholesterol-­lowering properties that often differ from properties of tocopherols (Fig. 8.2).

Tocopherols Wheat germ oil has the highest tocopherol content (>2000 mg/kg) of all vegetable oils, consisting mainly of α-tocopherol with β-tocopherol and γ -tocopherol in lower proportions, and low concentrations of δ-tocopherol (Fig. 8.2).

Carotenoids Carotenoids are fat-soluble pigments synthesized by plants with >700 compounds identified along with hydroxylated derivatives, xanthophylls. Approximately 50 of these are found in the human diet (Figs. 8.3 and 8.4).

Xanthophylls Xanthophylls are oxygen-containing carotenoids highly concentrated in the light-­ exposed structures in plants and in the human retina (Fig. 8.7).

Lutein Lutein is the most widespread pigments in nature. These are lipo-soluble anti-­ oxidants produced by plants, algae, fungi, and some bacteria. Wheat kernel contains ~0.5 μg/g (Fig. 8.6).

Zeaxanthin Zeaxanthin is one of the most common carotenoid alcohols found in nature and used as a nutritional carotenoid (Fig. 8.7).

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Meso-zeaxanthin Meso-zeaxanthin is not generally present in the diet. It is converted from lutein in the macula (Fig. 8.8).

β-cryptoxanthin β-cryptoxanthin is an oxygenated carotenoid with a chemical structure similar to, but more polar than, β-carotene. Although β-carotene is present in large amounts in numerous fruits and vegetables, β-cryptoxanthin found at high concentrations in only a small number of foods (Burri et al. 2016) (Fig. 8.5).

Picrocrocin Picrocrocin is a monoterpene glycoside precursor of safranal. It is found in the spice saffron, which comes from the crocus flower. It has a bitter taste and is the chemical most responsible for the taste of saffron.

Safranal Safranal is a compound isolated from saffron and is responsible for the aroma of saffron.

Hemiketal Hemiketal or hemiacetal is a compound that results from the addition of an alcohol to an aldehyde or a ketone, respectively.

Aglycone Aglycone is the compound remaining after the glycosyl group on a glycoside is replaced by hydrogen atom.

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The Yellow Pigments The total carotenoid content is usually estimated by quantifying total yellow pigments based on spectrophotometric determination.

15. Methyl Donors Methyl donors include betaine, choline (vitamin B4), and trigonelline. For many individuals, the endogenic synthesis is insufficient for the optimal physiological state. Therefore, all of these compounds are conditional vitamins (Figs. 8.9, 8.10, 8.11, and 8.12).

Glutathione Glutathione is an anti-oxidant present in plants, animals, fungi, and some bacteria and archaea. In humans, glutathione is produced naturally by the liver. Also, it is found in fruits, vegetables, and meats and is capable of preventing damage to the cellular components caused by the reactive oxygen species. People take glutathione by mouth for many reasons. The wheat kernel contains ~70 μg/g (Fig. 8.1).

16. Minerals Minerals are defined according to the daily RDA for adult: macro (major), micro (trace), ultratrace, and toxic.

Macroelements (Major Minerals) The following are macroelements in human nutrition: sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), and chlorine Cl.

Microelements (Trace Elements) They are sorted with the descending order of the weight requirement according to the RDA: iron (Fe), zinc (Zn), manganese (Mn), fluorine (F), copper (Cu), molybdenum (Mo), silicon (Si), chromium (Cr), nickel (Ni), selenium (Se), iodine (I), and cobalt (Co).

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Ultra-Trace Elements Within the ultra-trace elements, some of them are possibly essential elements that include boron (B), silicon (Si), nickel (Ni), vanadium (V), and tin (Sn).

Toxic elements Some of the toxic elements are mostly present in our environment: mercury (Hg), lead (Pb), arsenic (As), and cadmium (Cd).

17. Anti-oxidant Status Anti-oxidant Anti-oxidant is a fundamental compound that enables seed preservation and its longevity with the general principle of survival and maintenance of high germination ability. Free radical-counteracting processes and detoxification mechanisms are closely related to control the prooxidant/anti-oxidant balance both during the seed storage and germination (Rajjou and Debeaujon 2008). To promote their longevity, seeds require efficient anti-oxidant systems; thus, a range of protective mechanisms prevent excessive oxidation of the macromolecules (Sano et al. 2016). The wheat kernel contains a numerous number of the anti-oxidants that enable the wheat to spread along with the widest global areas and to use as the staple food in the highest number of cultures. Anti-oxidants are one of the two interconnected and bound main pillars of the wheat nutritional advantage (the second pillar is the dietary fiber). Their widespread intake might advent remarkably the human well-being.

Reactive Oxygen Species (ROS) Reactive oxygen species (ROS) are chemical species containing oxygen such as peroxides, superoxide, hydroxyl radical, and singlet oxygen.

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Reactive Nitrogen Species (RNS) Reactive nitrogen species (RNS) are a family of antimicrobial molecules derived from nitric oxide (•NO) and superoxide (O2•−) produced via the enzymatic activity of inducible nitric oxide synthase 2 (NOS2) and NADPH oxidase, respectively. NOS2 expressed primarily in macrophages after induction by cytokines and microbial products (Wikipedia).

Trolox Trolox is a compound used to evaluate the anti-oxidant capacity of foods and vitamin E analog (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) and is a water-soluble anti-oxidant. Because of the difficulty in measuring individual anti-­ oxidant components of a complex mixture, Trolox equivalency is used as a benchmark for the anti-oxidant capacity of such a mixture. Trolox equivalent anti-oxidant capacity (TEAC) is a measurement of anti-oxidant strength based on Trolox Equivalents (TE), e.g., micromole TE/100 g (Wikipedia).

DPPH (1,1-diphenyl-2-picrylhydrazyl) DPPH (1,1-diphenyl-2-picrylhydrazyl) is a compound used to evaluate anti-oxidant capacity (Fig. 4.6).

Oxygen Radical Absorbance Capacity (ORAC) ORAC (oxygen radical absorbance capacity) is a scalar value derived in the laboratory for comparing anti-oxidant capacity of different food or nutritional supplements (developed at the NIH).

Malondialdehyde Malondialdehyde results from lipid peroxidation of polyunsaturated fatty acids.

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Total Phenolic Content (TPC) Total phenolic content (TPC), an equivalent of ferulic acid, mg/g, might be determined by using the Folin-Ciocalteu method, which allows the estimation of all the flavonoids, anthocyanins, and nonflavonoid phenolic compounds that is, of all the phenolics, present in the samples.

18. Milling White Flour White flour is a kind of flour refined with the extraction rate of 300 sec) indicate minimal enzyme activity and sound quality wheat or flour, while a low number (< 250 sec) indicate substantial enzyme activity and sprout-damaged wheat or flour (Causgrove 2004).

Zeleny Sedimentation The sedimentation rate of the flour suspension in the lactic acid solution that affects the swelling of the gluten in the lactic acid. Higher gluten content and better quality give rise to slower sedimentation. It provides information about bread-making quality to estimate the loaf volume (Banu and Aprodu 2015).

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Farinograph Measures Farinograph is a tool for measuring the shear and the viscosity of a mixture of flour and water. It is the measurement used for the objective evaluation of a variety of flour qualities such as water absorption, dough viscosity, flour stability under mixing, and gluten tolerance.

Extensograph On the basis of the recorded extensograph, reliable information on the rheological dough properties, and therefore later the baking results, can be determined. Extensograph is useful in recognizing and determining the effects of flour additives, such as enzymes or ascorbic acid. The two most important parameters obtained by the extensograph are as follows: Extensograph water absorption The extensograph water absorption is the water volume (mL) per 100 g of flour at 14.0 % water content required to produce a dough with a standard consistency after 5 min mixing, under the operating conditions specified in the standard. Mixograph Mixograph measures and records the resistance of dough to mixing with pins. Test quickly analyzes small quantities of flour for dough gluten strength. Wheat breeders screen early generation lines for dough gluten strength. Flour water absorption measured by the mixograph often serves as bake absorption in bread-­baking tests (Causgrove 2004). Water activity or aw in the field of food science in the standard state is most often defined as the partial vapor pressure of pure water at the same temperature. Aw of pure distilled water equals 1. As the temperature increases, aw typically increases. Higher aw substances tend to support more microorganisms. Bacteria usually require >0.91 and fungi >0.7 (Wikipedia).

Mold Mold is an infection (e.g., of the bread or cake) caused by contamination after the product has been baked. Yellow, green, black, white, and red bread molds occur. Molds are related to fungi.

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Rancidity Rancidity is a condition of being rancid, which usually applies to fats and fatty foods. The main type of rancidity is oxidative. It is manifested by the appearance of an objectionable odor. This type may be responsible for off-flavor in bakery products, especially under long storage. Anti-oxidants have the effect of delaying the onset of such rancidity.

Ripeness Ripeness is a condition of the dough at the completion of correct fermentation where the maximum amount of elasticity and maturity exists in the dough.

Rope Rope is a disease of bread characterized by the appearance in the bread of a sharp acidic, fruity odor and then by the formation of slimy strings in the crumb. It may be caused by any of the several species of bacteria, but the one responsible for the majority of rope is the common soil bacteria, Bacillus mesentericus.

Shortening Shortening is any type of solid fat used in the production of bread, cakes, and other bakery products. It derived its name from its effect in making the product short and tender.

Sours Sours usually containing lactic and acetic acids as well as other flavoring materials, that are added mostly to rye bread but occasionally to wheat bread for the benefit of their distinctive flavors. Sourdough bread is bread made using fermenting dough, that has a slightly sour taste.

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Staling Staling refers to the drying out of fresh bread over a period time. Starch crystallization over time contributes to a dry eating character that is no longer perceived as fresh.

20. Chemical Reactions Related to Baking Caramelization Caramelization is the browning of sugar, which is a process used extensively in cooking for the resulting sweet nutty flavor and brown color. The brown colors are produced by three groups of polymers: caramel C24H36O18, caramel C36H50O25, and caramel C125H188O80s.

Strecker Degradation Strecker degradation refers to all types of oxidative deamination of amino acids caused by reagents. Besides the aldehydes, many other important flavor compounds can be formed in these reactions (Rizzi 2008).

Maillard Reaction The reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, pan-fried dumplings, cookies, and other kinds of biscuits, bread, toasted marshmallows, as well as many other foods, undergo this reaction. A reaction is a form of nonenzymatic browning which typically proceeds rapidly from ~140 to 165 °C.

Acrylamide Production Acrylamide production is used primarily to make polyacrylamide and acrylamide copolymers in many industrial processes. In food processing, its formation is closely related to the development of the desired sensory properties (color, flavor, and texture) of the baked products, but in the body, acrylamide is converted to glycidamide, which causes mutations and other deleterios effects. In some studies, dietary acryl-

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amide exposure was found to be associated with the risk of cancer. The major food sources of acrylamide are French fries and potato chips, crackers, and cookies.

21. Morbidity and Medical Terms Malignancy Historically, cancer has been thought of as a genetic disease driven by the accumulation of multiple mutations. However, recently, this paradigm has begun to shift, and cancer often regarded as a metabolic disease which is influenced by complex interactions between the tumor and its microenvironment (Turgeon et al.2018). The cellular concentration of the reactive oxygen species (ROS) might be one of the main causes of malignancy that might be moderated by the anti-oxidant supplementation (Karihtala and Soini 2007). Breast cancer has an incidence of 94 and 122 in 100,000 in Europe in 2006 and in the United States in 2012, respectively. The intake of the whole wheat affects the disease by a relative risk of 0.70 (Table 15.1). Lung malignancy Lung malignancy is a leading cancer cause worldwide. Colorectal cancer Colorectal cancer has an incidence of 45 and 39 in 100,000 in Europe in 2006 and in the United States in 2012, respectively. The intake of the whole wheat affects the disease by a relative risk of 0.78 (Table 15.1). Pancreas cancer Pancreas cancer has an incidence of 12.3 in 100,000 in the United States in 2012. The intake of the whole wheat affects the disease by a relative risk of 0.70 (Table 15.1). Prostate cancer Prostate cancer has an incidence of 86 and 105 in 100,000 in Europe in 2006 and in the United States in 2012, respectively. Small intestine cancer Small intestine cancer, or upper gut malignancy, has an incidence of 2.3 in 100,000 in the United States in 2012. The intake of the whole wheat affects the disease by a relative risk of 0.57 (Table 15.1). Glioblastoma Glioblastoma represents ~15% of the brain tumors. It is diagnosed by a CT scan, an MRI scan, and a tissue biopsy. Atherosclerosis Atherosclerosis is a disease in which plaque builds up inside the arteries, thus slowing or completely blocking blood flow to that specific organ. Coronary artery disease (CAD)

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Coronary artery disease, also known as coronary heart disease (CHD), occurs when waxy substances called plaque build up inside the coronary arteries and become hardened and narrowed. The disease is the leading death cause in all of the developed societies. The intake of the whole wheat affects the disease by a relative risk of 0.76 (Table 15.1). Adiposity Adiposity is defined according to the BMI as the most prevailed methodology to measure adiposity. Body circumference measurements might be a better predictor for the adiposity impairments. Stroke A stroke happens when blood flow to a part of the brain stops. It can cause paralysis of the limbs, speaking difficulty, cognitive impairment, and many other. Whole wheat intake affects the disease by a relative risk of 0.82 (Table 15.1). Dementia Dementia is a broad group of brain diseases that cause a long-term and often gradual decrease in the ability to think and remember, affecting a person’s daily functioning. Alzheimer’s disease Alzheimer’s disease is an irreversible, chronic neurodegenerative disease of progressive brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. It causes 60–70% of the dementia cases. Vascular dementia These are processes caused by impaired blood flow to the brain causing brain damage resulting from problems with reasoning, planning, judgment, memory, and mental illnesses.

Fibrogenesis Fibrogenesis is the formation of connective tissue, especially to an excessive degree or imperfectly.

Diabetes Mellitus Diabetes mellitus (honey-sweet diabetes) is a group of metabolic diseases in which there is high blood glucose over a prolonged period. Diabetes complications include heart attack, stroke, kidney failure, limb amputation, blindness, and nerve damage. The intake of the whole-wheat affects the disease by a relative risk of 0.74 (Table 15.1).

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Glycemia Glycemia is the blood glucose concentration, mostly refers as hyper- or hypo-.

Glycemic Index Glycemic index is a number associated with a particular type of food that indicates the food effect on a person’s blood glucose.

HbA1c Hemoglobin A1c (HbA1c), also known as glycosylated or glycated hemoglobin, is a hemoglobin form that is bound to glucose. Blood HbA1c levels are reflective of how well diabetes mellitus is controlled. HbA1c levels are reflective of blood glucose levels over the past 2–3 months and do not reflect the daily ups and downs of blood glucose. The normal level for hemoglobin A1c is less than 5.7% of the total hemoglobin. A value of 5.7–6.4% is called pre-diabetic state and a level of >6.5% signals diabetes mellitus. Medically treated diabetic patients should have HbA1c levels of less than 7%.

Diabetic Retinopathy Diabetic retinopathy, also known as diabetic eye disease, is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is the leading cause of blindness in the Western world.

Hip Fracture Hip fracture is a serious femoral fracture that occurs at the proximal end of the femur (the long bone running through the thigh), near the hip. It usually occurs in people who suffer from osteoporosis (Wikipedia).

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Inflammatory Response The immune system is a system of many biological structures and processes within an organism that protects against disease. Recently, inflammation has been found as a key element in the pathological progression of many organ diseases, i.e., cardiovascular disease, chronic liver disease, or diabetes mellitus (Chen et al. 2018). The intake of the whole wheat affects the disease by a relative risk of 0.77 (Table 15.1).

Inflammation Inflammation is a part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants (Wikipedia).

Metabolic Syndrome Metabolic syndrome encompasses cluster of metabolic abnormalities linked to cardiovascular risk factors (hypertension, dysglycemia, dyslipidemia, insulin resistance, and android fat) and associated with an increased prevalence of obesity, type 2 diabetes mellitus, and cardiovascular diseases (Goncalves and Amiot 2017).

Respiratory Diseases These are pathological conditions affecting the organs and tissues that make gas exchange possible. The intake of the whole wheat affects the death incidence of respiratory diseases by a relative risk of 0.72. (Table 15.1).

Macular Degeneration Commonly referred to as AMD, age-related macular degeneration is the leading cause of severe, irreversible vision loss in people >60. It occurs when the small central portion of the retina, known as the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye.

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Osteoarthritis Osteoarthritis is a type of joint disease that results from the breakdown of joint cartilage and underlying bone.

Opacification Opacification is the process of becoming cloudy or rendering opaque.

Hyperoxaluria Hyperoxaluria is the excessive urinary excretion of oxalate. Primary hyperoxaluria is an inherited error of metabolism due to defective enzyme activity. In contrast, secondary hyperoxaluria is caused by increased dietary ingestion of oxalate, precursors of oxalate, or alteration in intestinal microflora. Hyperoxaluria is the main cause of kidney stones.

Attention-Deficit Hyperactivity Disorder (ADHD) Attention-deficit hyperactivity disorder (ADHD) is a mental disorder of neurodevelopmental type. It is characterized by difficulty paying attention, excessive activity, or difficulty controlling behavior which is not appropriate for the age of the person (Wikipedia).

Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. It is caused by long-term exposure to irritating gases or particulate matter, most often from cigarette smoke. People with COPD are at increased risk of developing heart disease, lung cancer, and a variety of other conditions.

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Irritable Bowel Syndrome (IBS) Irritable bowel syndrome (IBS) is a group of symptoms with abdominal pain and changes in the movement of the bowel pattern without evidence of underlying damage. The Rome criteria IV for IBS require that patients have had recurrent abdominal pain or discomfort associated with defecation, at least 1 day per week in the last 3 months.

Non-Celiac Gluten Sensitivity (NCGS) Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food in subjects that are not affected by either celiac disease or wheat allergy. The terminology “NCGS” is still a matter of debate (Catassi et al. 2015).

Nocebo Nocebo is an effect that occurs when negative expectations of the patient regarding a treatment cause the treatment to have a more negative effect than it otherwise would have.

Telomere Telomere is a region of repetitive nucleotide sequences at each end of a chromosome, which protects the end of the chromosome from deterioration.

Parenteral Nutrition It is a method administered by some means other than oral or gut delivery, in particular intravenously or by injection.

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Enteral Nutrition Food or drug administered via the gastrointestinal tract by mouth, esophagus, ­stomach, and intestines.

Tumor Necrosis Factor-α (TNF-α) Tumor necrosis factor-α (TNF-α) is a cell signaling protein (cytokine) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction.

Cytokines Cytokines are small proteins acting in cell signaling.

IL-6 (Interleukin) Interleukin acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine.

Anti-Inflammatory IL-10 Interleukin 10 (IL-10), an anti-inflammatory cytokine

T-Helper Cells T-helper cells, also known as CD4+ cells, are a type of T cell that plays an important role in the immune system, particularly in the adaptive immune system.

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Human Leukocyte Antigen (HLA) Human leukocyte antigen (HLA) is a gene complex encoding the major histocompatibility complex proteins in human. These cell surface proteins are responsible for the regulation of the immune system in humans. The HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-­ tune the adaptive immune system (Wikipedia).

C-Reactive Protein (CRP) C-reactive protein is a test marker for inflammation. It is produced in the liver, and its level is measured by testing the blood.

HMG-CoA Reductase HMG-CoA reductase is a hepatic enzyme responsible for the synthesis of the cholesterol.

Xenobiotic Xenobiotic is a substance that is foreign to the body.

Apoptosis Apoptosis is a form of programmed cell death that is mediated by the intracellular program. Necrosis is a non-physiological process of cell death that occurs as a result of infection or injury.

Autophagy Autophagy is the natural, regulated, destructive mechanism of the cell that disassembles unnecessary or dysfunctional components. It allows the orderly degradation and recycling of cellular components and is the most important process in brain integrity as the brain does not renew his cells by apoptosis. The plethora of anti-­

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oxidants and other related compounds in the wheat kernel envelope might assist the regular activity of the autophagy.

Mitophagy Mitophagy is the selective autophagy of damaged mitochondria (Eun and Kyeong 2008).

Resting Metabolic Rate (RMR) Resting metabolic rate (RMR) is the whole-body metabolism during the time period of strict and steady resting conditions.

Osmolyte Osmolytes are compounds that affect osmosis. These are organic solutes that help the cell to adapt to dehydration or fluid excess. It generated within the cell in response to the osmotic stresses.

22. Medical Methodologies Angiography Angiography is an imaging technique used to visualize the inside, or lumen, of the blood vessels and organs of the body, with a particular interest in the arteries, veins, and the heart chambers.

B-Mode Ultrasonography The high-resolution B-mode ultrasonography enables quantitative measurement of the thickness of the intima-media layer of superficial large arteries noninvasively.

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Intima-Media Thickness (IMT) Intima-media thickness (IMT) is a marker of subclinical atherosclerosis (asymptomatic organ damage). Routinely, IMT measured ultrasonically at the carotid the thickness of tunica intima and tunica media, the innermost two layers of the artery wall. ITM is considered as abnormal at the range of >0.9 mm. The intake of the whole wheat affects the disease by a relative risk of 0.81 (Table 15.1).

Tunica Media (Intima) It is the innermost tunica (layer) of an artery or vein.

Computed Tomography (CT) Angiography It is a computed tomography technique used to visualize arterial and venous vessels throughout the body (within other visualizations). Using contrast injected into the blood vessels, it can visualize the vessels of the heart, the aorta, and other blood vessels.

Coronary CT Angiography It is an imaging test widely used by cardiologists to aid in the diagnosis of coronary artery disease, particularly when other test results may be equivocal. It is also of interest because of its ability to detect and possibly quantitate overall plaque burden and certain characteristics of plaques that may make them prone to ruptures, such as positive remodeling or low attenuation (Mozaffarian et al. 2015). It is a noninvasive technique, thus more comfortable for the patient.

Coronary Angiography It has high diagnostic accuracy for the invasive assessment of coronary artery disease, and findings of coronary computed tomographic angiography hold strong prognostic significance; thus, coronary angiography plays an important role in the evaluation and management of patients with known or suspected ischemic heart disease (Meinel et al. 2015).

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Magnetic Resonance Imaging (MRI) Using this device, a much better resolution might be gained for personal anamnesis and consequently in the study resolution and accuracy. However, because of the present high cost of the MRI analysis, no studies that used MRI have been included in this book.

EHR EHR (electronic health records) is the systematized collection of patient and population electronically stored health information in a digital format (Wikipedia). Efficient EHR clinical studies must be a comprehensive system, contain a large subject number, and equipped with sophisticated control devices, with efficient retrieving means and controlled permission approach. Such a system is most vulnerable to improper activity but supplies efficiently the most extensive excellent medical data. Only limited data related to the whole wheat intake were available to present in this book.

23. The Gut Foregut Foregut is the upper gut from the mouth to the duodenum at the entrance of the bile duct.

Cardia Cardia is the site where the contents of the esophagus empty into the stomach.

Fundus (Stomach) Fundus is the stomach site that bulges up past the point of entry of the esophagus.

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Antrum It is the lowermost part of the stomach with somewhat funnel-shaped, which empties into the duodenum.

Pylorus The pylorus connects the stomach to the duodenum and is considered as having the pyloric antrum (opening to the body of the stomach) and the pyloric canal (opening to the duodenum). The pyloric canal ends as the pyloric orifice, surrounded by a sphincter (a band of muscle) which marks the junction between the stomach and the duodenum (Wikipedia).

Oddi Sphincter It is a muscular valve that controls the flow of the bile and pancreatic juice into the duodenum.

Ileum The ileum is the final section of the small intestine.

Terminal Ileum Terminal ileum is the distal ileum segment with the most important reabsorptive role of the bile acids. In the terminal ileum, the epithelial cells express the apical sodium-dependent bile acid transporter (ASBT) which can transport only bile acids contrary to other bile transporters that can transport other molecules. ASPT is an efficient bile transporter with a greater affinity for conjugated bile acids over those that are not (Hegyi et al 2018).

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Ileocecal Junction (Ileocecal Valve) Ileocecal junction is a sphincter muscle valve that separates the terminal ileum of the small intestine and the large intestine. Its critical function is to limit the reflux of colonic contents into the ileum. Approximately 2 liters of fluid enters the colon daily through the ileocecal valve (Wikipedia).

Rugae (Stomach) Rugae is a series of ridges produced by folding of the stomach wall.

Villus/Villi (Intestinal) Villus is the finger-like projection that extends into the lumen of the small intestine with a length of ~0.5–1.6 mm and has many microvilli projections.

Digesta Digesta is alimentary tract contents that undergo digestion.

Microbiota (in the Colon) Microbiota is a community of commensal and symbiotic bacteria (of some phyla), fungi, yeast, archaea, and viruses (bacteriophages). The colon microbiota contain densely populated microbial ecosystem, which is known in nature, with 102 yeast, 102 fungi, 109 archaea (methane forming organisms), up to 1012 bacteria/mL, 1013 bacteriophages/mL, 1014–1015 bacteria in the whole colon, and up to 1016 bacteriophages/ whole colon. Microbiota play an important role in immunologic, hormonal, and metabolic processes in their host.

Microbiome Microbiome is the total genome of the microbiota.

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Shannon Index Shannon index designates the microbial diversity; high value shows high diversity.

Bolus Bolus is a ball-like mixture of food and saliva that forms in the mouth during chewing. It has the same color as the food eaten, and the saliva gives it an alkaline pH.

Chyme Chyme is the semi-fluid mass of partly digested food that expelled by the stomach, through the pyloric valve, into the duodenum.

Foveolar Cells Foveolar cells are mucus-producing cells that cover the inside of the stomach, protecting it from the corrosive nature of the gastric fluid.

Gastric Parietal Cells Gastric parietal cell, also known as oxyntic cell, is a remarkable physiological entity in view of its regulation and participation in the digestion. It has the ability to secrete hydrochloric acid (HCl) at high concentration with a voluminous rate by the activity of a membrane-bound protein, the H,K-ATPase (consists ~5% of total cell protein), that pumps H in exchange for K as the primary proton pump (Forte 2010). It also secretes intrinsic factor, a protein that binds to vitamin B12 and allows for its absorption in the terminal ileum.

Gastric Chief Cell Gastric chief cell is a cell in the stomach that releases pepsinogen and chymosin.

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Gastric Intrinsic Factor It is a glycoprotein produced by the parietal cells of the stomach that binds to vitamin B12 and enables the absorption of the vitamin in the ileum.

Bile Salts Bile acids are conjugated with taurine or glycine and produce salts with sodium and potassium. Primary bile acids are those synthesized by the liver. Secondary bile acids result from bacterial actions in the colon. Bile acids are about 80% of the organic compounds in the bile (others are phospholipids and cholesterol). The main function of the bile acids is to allow the digestion of dietary fats and oils and to extremely decrease the microbiota in the upper gut. They also have hormonal actions throughout the body.

Enterohepatic Cycle Enterohepatic cycle is a metabolic cycle that transports a total amount of ~10 g/d with ~10 cycles from the liver cell into the gallbladder, the duodenum, the jejunum, and the majority of the ileum. At the terminal ileum, most of the bile absorbed into the portal blood with continuous absorption along the colon into the portal blood while only minor content excreted in the feces. The bile from the portal vein is absorbed by the liver cells and transported into the gallbladder, thus beginning the next cycle. The cycle enhances bile transporters.

24. Lipids in Human Organs Lipoprotein It is a complex whose primary purpose is to transport hydrophobic lipid molecules in water, like blood. They have a single-layer phospholipid and cholesterol outer shell, with the hydrophilic portions oriented outward toward the surrounding water and lipophilic portions of each molecule oriented inward toward the lipid molecules within the particles. They are mainly classified on the density basis as: chylomicron, very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Cholesterol (including cholesteryl esters), phospholipids, and triglycerides are the three major lipid types in the plasma. Cholesterol is the most

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abundant polycyclic sterol ­compound. Lipids are suspended in the plasma by the lipoprotein particles that form a coat around. It consists of a nonpolar lipid core of mainly cholesteryl ester and triacylglycerols and an outer phospholipids layer, unesterified cholesterol, and proteins. The lipoprotein particle transports lipids such as cholesterol or triglycerides around the body. LDL It is one of the five major groups of lipoproteins which transport all fat molecules around the body in the extracellular water. It delivers fat molecules to the cells and can drive the progression of atherosclerosis if they become oxidized within the walls of arteries and carry 60–70% of the total serum cholesterol. HDL It is one of the five major groups of lipoproteins that are composed of 80–100 proteins per particle transporting up to hundreds of fat molecules per particle. Increasing concentrations of HDL particles are associated with decreasing accumulation of atherosclerosis within the arteries walls. HDL particles are referred to as “good cholesterol” because they can transport fat molecules out of artery walls, reduce macrophage accumulation, and help prevent or even regress atherosclerosis. It contains 20–30% of the total serum cholesterol. High plasma cholesterol and in particular LDL are linked to a high incidence of coronary artery diseases (Ahmadraji and Killard 2013; Sirtori and Fumagalli 2006). Despite reductions in LDL, residual risk remains. There was an increasing emphasis on identifying other lipids, apolipoproteins, and their ratios to improve risk prediction. With the discovery and increasing use of other measures, such as non-HDL-C and apoB100, coupled with techniques to measure these, which are standardized and less influenced by diet, there will undoubtedly be a drive to include these within future risk prediction models after their cost-effectiveness over traditional markers has been assessed (Hadjiphilippou and Ray 2018).

VLDL Cholesterol Very-low-density lipoprotein cholesterol is produced in the liver and released into the bloodstream to supply triglycerides. About half of a VLDL particle is made up of triglycerides. High levels of VLDL cholesterol are associated with the development of plaque deposits on artery walls, which narrow the passage and restrict blood flow. Because no simple and direct way is available to measure VLDL cholesterol, VLDL normally is not mentioned within the routine cholesterol screening (MedLinePlus).

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Gamma-Aminobutyric Acid Gamma-aminobutyric acid (GABA) or γ-aminobutyric is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is to reduce neuronal excitability throughout the nervous system which is directly responsible for the regulation of the muscle tone.

25. Organizations AACC International The American Association of Cereal Chemists International is a nonprofit professional organization of specialists in the use of cereal grains in foods.

AOAC International The Association of Official Analytical Chemists International is a nonprofit scientific association. It publishes standardized, chemical analysis methods designed to increase confidence in the results of chemical and microbiologic analyses. Government agencies and civic organizations in the United States often require laboratories to follow official AOAC methods.

FOB Food and Nutrition Board of the US National Academy of Science, the institute that publishes the DRI (Dietary Reference Intakes), the general term for a set of reference values used to plan and assess nutrient intakes of healthy people with the periodic updates

FDA The US Food and Drug Administration, within all other tasks, sets the upper-level values of dietary intakes mainly according to animal experimentation.

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IOM The Institute of Medicine is a component of the US National Academy of Sciences that publishes the DRI.

References Ahmadraji T, Killard AJ (2013) The evolution of selective analyses of HDL and LDL cholesterol in clinical and point of care testing. Anal Methods 5:3612–3625. https://doi.org/10.1039/ c3ay40715b Anderssen RS, Bekes F, Gras PW, Nikolov A, Wood JT (2004) Wheat-flour dough extensibility as a discriminator for wheat varieties. J Cereal Sci 39:195–203. https://doi.org/10.1016/j. jcs.2003.10.002 Andersson AAM, Dimberg L, Åman P, Landberg R (2014) Recent findings on certain bioactive components in whole-grain wheat and rye. J Cereal Sci 59:294–311. https://doi.org/10.1016/j. jcs.2014.01.003 Arifkhodzhaev AO (2000). Galactans and galactan-containing polysaccharides of higher plants. Chem Nat Compd 36:229-244. doi: https://doi.org/10.1007/BF02238327 Aw D, Silva AB, Palmer DB (2007) Immunosenescence: emerging challenges for an ageing population. Immunology 120:435–446. https://doi.org/10.1111/j.1365-2567.2007.02555.x Banu I, Aprodu I (2015) Association of physicochemical with technological properties of wheat. Int J Food Sci Technol 50:1644–1650. https://doi.org/10.1111/ijfs.12816 Burri BJ, La Frano MR, Zhu C (2016) Absorption, metabolism, and functions of β-cryptoxanthin. Nutr Rev 74:69–82. https://doi.org/10.1093/nutrit/nuv064 Burton RA, Fincher GB (2014) Evolution and development of cell walls in cereal grains. Front Plant Sci 5:456. https://doi.org/10.3389/fpls.2014.00456 Cardoso LDM, Pinheiro SS, Martino HSD, Pinheiro-Sant’Ana HM (2017) Sorghum (Sorghum bicolor L.): nutrients, bioactive compounds, and potential impact on human health. Crit Rev Food Sci Nutr 57:372–390. https://doi.org/10.1080/10408398.2014.887057 Catassi C, Elli L, Bonaz B, Bouma G, Carroccio A, Castillejo G, Cellier C, Cristofori F, Magistris LD, Dolinsek J, Dieterich W, Francavilla R, Hadjivassiliou M, Holtmeier W, Körner U, Leffler DA, Lundin KEA, Mazzarella G, Mulder CJ, Pellegrini N, Rostami K, Sanders D, Skodje GI, Schuppan D, Ullrich R, Volta U, Williams M, Zevallos VF, Zopf Y, Fasano A (2015) Diagnosis of non-celiac gluten sensitivity (NCGS): the Salerno experts’ criteria. Nutrients 7:4966–4977. https://doi.org/10.3390/nu7064966 Causgrove L (2004) Wheat and flour testing methods: a guide to understanding wheat and flour quality. Wheat Mark Center, Inc 1:1–73. Chen L, Deng H, Cui H, Fang J, Zuo Z, Deng J, Li Y, Wang X, Zhao L (2018) Inflammatory responses and inflammation-associated diseases in organs. Oncotarget 9:7204–7218. https:// doi.org/10.18632/oncotarget.23208 Cochrane MP (1983) Morphology of the crease region in relation to assimilate uptake and water loss during caryopsis development in barley and wheat. Aust J Plant Physiol 10:473–491 Craft BD, Kerrihard AL, Amarowicz R, Pegg RB (2012) Phenol-based antioxidants and the in vitro methods used for their assessment. Compr Rev Food Sci Food Saf 11:148–173. https:// doi.org/10.1111/j.1541-4337.2011.00173.x EU Science Hub. https://ec.europa.eu/jrc/en/health-knowledge-gateway/promotion-prevention/ nutrition/whole-grain#_Toc479239822 Eun HK, Kyeong SC (2008) A critical role of superoxide anion in selenite-induced mitophagic cell death. Autophagy 4:76–78. https://doi.org/10.4161/auto.5119

Definitions

513

Fahy E, Cotter D, Sud M, Subramaniam S (2011) Lipid classification, structures and tools. Biochim Biophys Acta 1811:637–647. https://doi.org/10.1016/j.bbalip.2011.06.009 FAOSTAT. http://www.fao.org/faostat/en/#home Ferruzzi MG, Jonnalagadda SS, Liu S, Marquart L, McKeown N, Reicks M, Riccardi G, Seal C, Slavin J, Thielecke F, Kamp JWVD, Webb D (2014) Developing a standard definition of whole-grain foods for dietary recommendations: summary report of a multidisciplinary expert roundtable discussion. Adv Nutr 5:164–176. https://doi.org/10.3945/an.113.005223 Ficco DBM, Mastrangelo AM, Trono D, Borrelli GM, Vita PD, Fares C, Beleggia R, Platani C, Papa R (2014) The colours of durum wheat: a review. Crop Pasture Sci 65:1. https://doi. org/10.1071/cp13293 Flander L, Rouau X, Morel MH, Autio K, Seppanen-Laakso T, Kruus K, Buchert J (2009) Effects of laccase and xylanase on the chemical andrheological properties of oat and wheat doughs. J Agric Food Chem 56:5732–5742 Forte JG (2010) The gastric parietal cell: at home and abroad. Eur Surg Acta Chir Austriaca 42:134–148. https://doi.org/10.1007/s10353-010-0539-9 Gao X, Wang Y, Randell E, Pedram P, Yi Y, Gulliver W, Sun G (2016) Higher dietary choline and betaine intakes are associated with better body composition in the adult population of Newfoundland, Canada. PLoS One 11:1–17. https://doi.org/10.1371/journal.pone.0155403 Goncalves A, Amiot MJ (2017) Fat-soluble micronutrients and metabolic syndrome. Curr Opin Clin Nutr Metab Care 20:492–497. https://doi.org/10.1097/MCO.0000000000000412 Hadjiphilippou S, Ray KK (2018) Lipids and lipoproteins in risk prediction. Cardiol Clin 36:213– 220. https://doi.org/10.1016/j.ccl.2017.12.002 Hegyi P, Maléth J, Walters JR, Hofmann AF, Keely SJ (2018) Guts and gall: bile acids in regulation of intestinal epithelial function in health and disease. Physiol Rev 98:1983–2023. https://doi. org/10.1152/physrev.00054.2017 HMDB. http://www.hmdb.ca/hml Jonsson K, Andersson R, Knudsen KEB, Hallmans G, Hanhineva K, Katina K, Kolehmainen M, Kyrø C, Langton M, Nordlund E, Lærke HN, Olsen A, Poutanen K, Tjønneland A, Landberg R (2018) Rye and health  - where do we stand and where do we go? Tr Food Sci Technol 79:78–87. https://doi.org/10.1016/j.tifs.2018.06.018 Kapral M, Wawszczyk J, Jurzak M, Hollek A, Węglarz L (2012) The effect of inositol hexaphosphate on the expression of selected metalloproteinases and their tissue inhibitors in IL-1β-­ stimulated colon cancer cells. Int J Colorectal Dis 27:1419–1428. https://doi.org/10.1007/ s00384-012-1445-3 Karihtala P, Soini Y (2007) Reactive oxygen species and antioxidant mechanisms in human tissues and their relation to malignancies. Apmis 115:81–103 Korczak R, Marquart L, Slavin JL, Ringling K, Chu YF, O’Shea M, Harriman C, Toups K, De Vries J, Jacques P, Klurfeld DM, Camire ME, Unnevehr L (2016) Thinking critically about whole-grain definitions: summary report of an interdisciplinary roundtable discussion at the 2015 Whole-Grains Summit. Am J Clin Nutr 104:1508–1514. https://doi.org/10.3945/ ajcn.115.126672.1 Lidon FC, Almeida AS, Leitão AL, Silva MM, Pinheiro N, Maçãs B, Costa R (2014) A synoptic overview of durum wheat production in the mediterranean region and processing following the european union requirements. Emirates J Food Agric 26:693–705. https://doi.org/10.9755/ejfa. v26i8.17066 MedLinePlus. https://medlineplus.gov/images/m_logo.png Meinel FG, Bayer RR II, Zwerner PL, Cecco CND, Schoepf UJ, Bamberg F (2015) Coronary computed tomographic angiography in clinical practice: state of the art. Radiol Clin North Am 53:287–296. https://doi.org/10.1016/j.rcl.2014.11.012 Mendez-Millan M, Dignac MF, Rumpel C, Derenne S (2011) Can cutin and suberin biomarkers be used to trace shoot and root-derived organic matter? A molecular and isotopic approach. Biogeochemistry 106:23–38. https://doi.org/10.1007/s10533-010-9407-8

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Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, Das SR, Ferranti SD, Després J-P, Fullerton HJ, Howard VJ, Huffman MD, Isasi CR, Jiménez MC, Judd SE, Kissela BM, Lichtman JH, Lisabeth LD, Liu S, Mackey RH, Magid DJ, McGuire DK, Mohler ER, Moy CS, Muntner P, Mussolino ME, Nasir K, Neumar RW, Nichol G, Palaniappan L, Pandey DK, Reeves MJ, Rodriguez CJ, Rosamond W, Sorlie PD, Stein J, Towfighi A, Turan TN, Virani SS, Woo D, Yeh RW, Turner MB (2015) Heart disease and stroke statistics  - 2016 update. Circulation 133:e38–e360. https://doi.org/10.1161/CIR.0000000000000350 Nirmal RC, Furtado A, Wrigley C, Henry RJ (2016) Influence of gene expression on hardness in wheat. PLoS One 11:1–17. https://doi.org/10.1371/journal.pone.0164746 Patel MJ, Chakrabarti-Bell S (2013) Flour quality and dough elasticity: dough sheetability. J Food Eng 115:371–383. https://doi.org/10.1016/j.jfoodeng.2012.10.038 Pritchard JR, Lawrence GJ, Larroque O, Li Z, Laidlaw HKC, Morell MK, Rahman S (2011) A survey of β-glucan and arabinoxylan content in wheat. J Sci Food Agric 91:1298–1303. https:// doi.org/10.1002/jsfa.4316 Rajjou L, Debeaujon I (2008) Seed longevity: survival and maintenance of high germination ability of dry seeds. C R Biol 331:796–805. https://doi.org/10.1016/j.crvi.2008.07.021 Ramseyer DD, Bettge AD, Morris CF (2011) Distribution of total, water-unextractable, and water-­ extractable arabinoxylans in wheat flour mill streams. Cereal Chem 88:209–216. https://doi. org/10.1094/CCHEM-10-10-0148 Rasouli H, Farzaei MH, Khodarahmi R (2017) Polyphenols and their benefits: a review. Int J Food Prop 20:1700–1741. https://doi.org/10.1080/10942912.2017.1354017 Rizzi GP (2008) The strecker degradation of amino acids: newer avenues for flavor formation. Food Rev Int 24:416–435. https://doi.org/10.1080/87559120802306058 Sano N, Rajjou L, North HM, Debeaujon I, Marion-Poll A, Seo M (2016) Staying alive: molecular aspects of seed longevity. Plant Cell Physiol 57:660–674. https://doi.org/10.1093/pcp/pcv186 Serrano J, Puupponen-Pimiä R, Dauer A, Aura AM, Saura-Calixto F (2009) Tannins: current knowledge of food sources, intake, bioavailability and biological effects. Mol Nutr Food Res 53:310–329. https://doi.org/10.1002/mnfr.200900039 Sirtori CR, Fumagalli R (2006) LDL-cholesterol lowering or HDL-cholesterol raising for cardiovascular prevention. A lesson from cholesterol turnover studies and others. Atherosclerosis 186:1–11. https://doi.org/10.1016/j.atherosclerosis.2005.10.024 Stalikas CD (2007) Extraction, separation, and detection methods for phenolic acids and flavonoids. J Sep Sci 30:3268–3295. https://doi.org/10.1002/jssc.200700261 Shewry P (2019) What is gluten—why is it special? Front Nutr 6:101. https://doi.org/10.3389/ fnut.2019.00101 Tagawa K, Kaji A (1988) Preparation of L-arabinan and 1,5-L-arabinan. Methods Enzymol 160:542–545 Turgeon M-O, Perry NJS, Poulogiannis G (2018) DNA damage, repair, and cancer metabolism. Front Oncol 8:15. https://doi.org/10.3389/fonc.2018.00015 UNIPROT. https://www.uniprot.org/ Wang S, Yu J, Xin Q, Wang S, Copeland L (2017) Effects of starch damage and yeast fermentation on acrylamide formation in bread. Food Control 73:230–236. https://doi.org/10.1016/j. foodcont.2016.08.002 Web of Science. https://clarivate.com/products/web-of-science/ Wikipedia. https://www.wikipedia.org/ Yang F, Jin ES, Zhu Y, Wu S, Zhu W, Jin Y, Song J (2015) A mini-review on the applications of cellulose-­binding domains in lignocellulosic material utilizations. BioResources 10:6081– 6094. https://doi.org/10.15376/biores.10.3.Yang