Characterization, production and application of food flavours: Proceedings of the 2nd Wartburg Aroma Symposium 1987. Organized by Central Institute of Nutrition Potsdam-Rehbrücke/GDR Academy of Sciences of the GDR Eisenach/GDR, November 16th–19th, 1987 [Reprint 2022 ed.] 9783112640906

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ABHANDLUNGEN DER A K A D E M I E D E R WISSENSCHAFTEN DER D D R Abteilung Mathematik - Naturwissenschaften - Technik Jahrgang 1988 • Nr. 2 N

Characterization, production and application of food flavours Proceedings of the 2nd Wartburg Aroma Symposium 1987

Organized by Central Institute of Nutrition Potsdam-Rehbriicke/GDR Academy of Sciences of the G D R Eisenach/GDR, November 16th-19th, 1987 Edited by Manfred Rothe

A K A D E M I E - V E R L A G BERLIN 1988

Herausgegeben im A u f t r a g e des Präsidenten der Akademie der Wissenschaften der D D R v o n Vizepräsident Prof. D r . Heinz Stiller

Die Beiträge dieser A b h a n d l u n g w u r d e n nach d e n O r i g i n a l m a n u s k r i p t e n der A u t o r e n r e p r o d u z i e r t .

ISBN 3-05-500594-5 ISSN 0138-1059

Erschienen im A k a d e m i e - V e r l a g Berlin, D D R - 1 0 8 6 Berlin, Leipziger Straße 3—4 © A k a d e m i e - V e r l a g Berlin 1988 L i z e n z n u m m e r : 202 • 100/374/88 Printed in the G e r m a n D e m o c r a t i c Republic Gesamtherstellung: I V / 2 / 1 4 V E B D r u c k e r e i »G. W . Leibniz«, 4450 G r ä f e n h a i n i c h e n • 7147 LSV 3695 Bestellnummer: 763 904 7 (2001/88/2N) 05200

P r e f a c e

Under the view or the consumer or foodstuffs flavour liy fur ho) (is the first, place among the attributes participutinrj to foot! quality. Consumption statistics of hicjhly developed countries clearly indicate this fact as well as the trend to more and more specialized and aroma-rich foods and meals. Whether this trend may he caused hy the consumer's behaviour itself or originates in the supply of food shops and restaurants with n broad and still increasing variety of spccial footls and delicacies is a question of secondary

importance.

As one of the consequences there is an increasing demand for food flavourings with respect to amount, and variety. Because of limits in the production and use of natural flavour resources new ways have to be developed and introduced in the flavour industry. This actual however, must be based on more basic knowledge and practical as important tools for the expanding flavour

task, experience

industry.

Discussions between the specialists of different countries can stimulate the progress and must be profitable for all experts working or

interested

in this rapidly developing field. With the organisation of the 2nd Wartburg Aroma Symposium the Central Institute of Nutrition Potsdam-Rehbrticke tries to contribute to this process by the discussion of actual

flavour

problems and the personal exchange of opinions. Wc hope that such activities indirectly will support the interest of the consumer, too, as flavour belongs to those physiological sensations which may produce pleasure, satisfaction and contentment in human life.

3

fiith pleasure we noticed the resonance of our invitiation to this meeting by the guest, lecturers as well as by a lot of expert groups within the socialistic countries. More than 50 % of the participants came from abroad thus rjivinn e good chance for an effective discussion of flavour problems from a different point of view.

I want to thank the Academy of Sciences of the GDR as well as the director of the Central Institute of Nutrition

Potsdam-Rehbrucke,

Prof. H. Schaandke, and his deputy, Prof. R. Uacholz for supporting our organisation work. As editor of these proceedings I am much indebted to lector Karl Abel from the Akademie-Verlag Berlin for an always good and effective atmosphere when discussing questions connected with the publication. Finally I am very much obliged to my colleagues Dr. H.-P. Kruse and Edith Seise for help and assistance in solving many detailed organisation problems as well as for correspondence and writing of manuscripts.

December 1987

Manfred Rothe

C o n t e n t s

Rothe, M., H. Ruttloff, R. Schrôdter and F.-O. Struber 'Actual trends in food flavouring'

7

Schreier, P. 'On line coupled HRGC techniques for flavour analysis'

23

Maarse, H., L. II. Mijssen and S. A. G . F. Angelino 'Chlorophenols and chloroanisoles: occurrence, formation and prévention' Roozen, 3. P. and 0. P. H. Linssen 'Effect of types I, II and III antioxidants on phospholipid oxidation in a meat model for warmed-over flavour'

63

Konja, G., T . Lovric and A. Pozderovfc 'Study on aroma recovery during production of concentrated juices' Szente, L. and 0. Szejtli 'New results on the molecular encapsulation of flavours with cyclodextrins' Schrodter, R., 3. Schlieaann and G. Vols 'Study on the cffect of fat in meat flavour formation'

73

103 107

Misharina, T . A . and R. V. Golovnja 'S-containing compounds in meat aroma model systems'

13 5

Schlieaann, 3., G . Kola and R. sensory Schrodter 'Comparative study on selected and gas chromatographic data of chicken flavour' Grosch, tr., P. Schieberle and F. Ullrich

120

'Bread flavour - qualitative and quantitative analysis'

139

Kaainski, E. and E. Vasowicz 'Effect of thermically treated malt additives on bread flavour'

153

Bratovanova, P. 'Influence of Bulgarian lactic acid leaven on aroma compounds in pre-ferments Golovnja, R. and V. in white bread prepared by intensive kneading'

1C5

'Thermodynamic approach to flavour research' Nykanen, 'PotentialL.means to improve the flavour of alcoholic beverages'

201

Orsi, F. 'Changing of coffee aroma during storage'

225

Thoaann, R . 3., U. Brâuer and P. Kretsctner 'Production and use of spice concentrates made from volatile oils of herbs'

245

Tietz, U. and K.-P. Roethe 'Results of extraction of Mojoran horterisis M. with supercritical gases'

251

5

Ruttloff, H. and M. Rothe ' Biotechnologi cal production of food flavourings'

259

Adda, 3. 'Natural and artificial checse flavour'

277

Ziegleder, C. evaluation by guide subsLarices in correlation 'Cocoacocoa flavour with processing' Rodel, V., D. Habisch and H. Ruttloff

289

'Formation of cocoa flavour by Mail lard reaction'

301

Rothe, U., I. ofVoigt H.-P. Kruseeffects based on sensory 'Calculation cocoaandsubstitution profile data'

311

Haenel, II. 'Flavor: the psychological category'

323

Barylko-Pikielna, N. "Time-intensity studies on taste; substances - an actual review'

335

Pokorny, 0. and 3. Davidek 'Methods of selection of descriptors and grading scales in the sensory profile analysis of foods' Hoppe, K. and V. Rodel 'Theoretical and methodological problems of absolute threshold determination' Neuaann, R. 'International trends in standardization of sensory methods'

377

Author index

387

Subject index

389

list of participants

399

6

349 307

ACTUAL TRENDS IN FOOD FLAVOURING M. Rothe, H. Ruttloff, R. Schrödter1^ and F.-J. Strüber 2 ^

Various aspects have stimulated our decision to focus this symposium somewhat to food flavouring problems. First of all there are three anniversaries in the flavouring field. In these days it is exactly 100 years ago that Gustav Theodor Fechner died who first discussed the relationship between stimulus concentration and stimulus response. This year a symposium in Leipzig remembered his well-known activities in the field of physics and physiology. Also exactly 100 years ago Wallach established the so-called 'isoprene rule' which gives us a simplified concept of the pathways of terpene biosynthesis: most terpenoids can be hypothetically constructed by a 'head-to-tail' joining of isoprene units. Though we know today that mevalonic acid is the real intermediate of terpene synthesis this one century old hypothesis has created much advance in the terpene field, and that means in the large area of essential oils which had and still have a central place in food flavouring. Finally it is now 100 years ago that the threshold value of an odorant was first determined by Emil Fischer and hie co-workers. Today the story looks rather curious for us: The determination was realized in such a way that known amounts of the odorant were sprayed into a room of known volume. After some time necessary to get an equal distribution single persons were asked to enter the room and to answer the question whether they could find an odour or not. Using different people, different concentrations and repeated tests it was possible to define the threshold values of thiophenol and chlorophenol, respectively, in air as the diluting medium. Most congresses in the flavour field held in the last two decades did not deal with flavouring problems directly. This may be the domaine of the flavour industry. In basic aroma research the activities are focussed first to the analytical sids of flavour and aroma. Here the progress reached in the last 25 years indeed was fascinating. Despite of high prices of modern gas chromatographic and spectrometric equipT5 'Zentralinstitut für Ernährung Potsdam-Rehbrücke, Akademie der Wissenschaften der DDR, Arthur-Scheunert-Allee 114/116, Bergholz-Rehbrücke, DDR-1505 2 *VEB Chemisches Werk Miltitz, Miltitz, DDR-7154

7

ments and of their steady improvement more and more flavour research groups make U3e of these modern techniques. Table 1. Trends in the use of modern chromatographic and spectrometric methods in aroma research (Data taken from literature documentation of the Central Institute of Nutrition Potsdam-Rehbriicke)

tested n u m b e r o f aroma publications classical methods* and reviews ( % ) GC methods

(%)

GC/MS m e t h o d s " l % ) HPLC methods ( % )

1970/75

1981/83

1984/86

1956/60

1965/69

300

1000

1100

1000

1000

95

77

63

52

41

4

14

22

27

27

1

9

14

18

25

3

7

T

f

r

* = s e n s o r y , enzymatic, TLC, PC and colorimetric methods * * s including GC combination with other spectrometric methods

* = i i

I 1,1 • i *

'i'fr, r' I i l i

\\\ \- VX1''

I i M I I i I 1,1 ì M .

Y i

ÌQOCOFWMOQI

V'N

I

--

! N CÇ N..

-

I 1! Z L1J 0 X 0 5

•

»

V C ITTI MI H CD

M 69

s s

m J

tìß 0

H « C ( \

pu ^ 10 H 0 h --J H o U Yô m s? i & * Pu tó

70

m LL

Plate h

A

U ~ ~E : : x : -• ~ S E r z E C T E DURING HEATING AND STORAGE. ~ TO ~ EXIL A \ ~ A EE_ EFFECTIVE DURING COED STORAGE, " T O . - " S A A R TO - S O - S — ; -OXIDANTS A T LOW CONCENTRATIONS AND IN M A W CASES - S AST -OXIDANTS AT HIGH SENSE TO-TONS. Du A N 3 S E S T O G - 0 S T O RAGE T T O PRODUCT STOUED EE PREVENTED FROM DRYING A S

71

A

STUDY

OF

AROMA

CONCENTRATED G.

Konja*,

*

RECOVERY

DURING

A.

Pozderovic* *,

T.

Prehrambeno-blotehno1 o$ki

**

THE

PRODUCTION

OF

JUICES

Prehrambeno-tehnolo3ki

Lovrlc*

fakultet

fakultet

Zagreb

Osljek

I n t r o d u c 11 o n There

is

world

market.

a

growing

their

use

In

increasing

the

the

demand to

the

food

attention

Concentrated for

Due

Juice

market

for

concentrated

wide

range

Industry Is

and

being

juices

and

as

consumer

to

their

since

aroma

this

on

the

possibilities

paid

concentrated

separately,

of

products,

production.

are

has

of

produced

numerous

advan-

tages. The

most

ces

today

widespread

vacuum), cess

Is still

regardless

(I).

fruit

a

by

The

components

sons

the

methods etc.

such

as

flexible

advantage

of

various

tion.

The

wadays two-

or

of

used can

Attempts

uslng

this

of

of

basic

with one

for be

applied

in

method

with

regard

kinds

of

with

or

to

to

evaporation

to

the rea-

osmosis,

is it

still is

with

large the

selectivity and plant

the

economi-

disby

concentraused

1 o w - 1 e m p e ra t u r ? ,

without

case

concen-

main

overcome

recovery

for

the

of

reverse

plants

made

aroma

in

a pro-

concentration

because

been

for

the

evaporation

juices

this

regard

of

alternative

concentration,

jui(in

criteria

selectivity

was

by

of

especially

especially juice,

hIgh-temperature,

multistage,

the

plant,

fruit

pressure

selectivity

have

systems

different

(e.g.

reduced

insufficient

freeze

and

concentrating at

poor

concentration

method

capacities.

of

one

Introduction

However,

prevailing cal,

Is

evaporation,

aromatic for

the

concentration

juices.

tration

of

Selectivity

evaluating of

method

evaporation

no-

single-,

thermocompressIon

and,

73

recently,

plants

(2),

been

have

energy

savings

plants

are

or

highly

of

differ yet

since

been

with

of

that,

ponsible

for

sence

in of

ristic been and

can

effective

concentration

(e.g.

Highly

volatile by

on,

while

azeotroplc

trate

at

high

with

a

high

dry

According

concenare

res-

In

the

fruit

when

the

pre-

are kind

the of

charactefruit

has

concentrate recovery

or

be

to

highly

Pilnlk

and

are

the

aromas

a7eotropic aroma).

separated of

partially

content.

which (3),

volatile

degree

evaporation,

solids

juices,

raspberry totally

lesser

aromas of

from

components

volatile,

aroma, can

greater

degrees

aroma

poorly

aromas

juice

compounds with

between

and

the

even

which

certain

aroma

strawberry

a

Only

com-

well

juice

complex

juice.

Is

which

an

difference

aromas

of

components

a

aromatic

aroma)

degree

It

of

points.

a

fruit.

have

aroma

demonstrated.

boiling

Is

of

specific

operation

have

apple

less

aroma

arifes

(e.g.

recovery

an

problem

there

has

concentrate

which

of

greatest low

fruit

aroma

constructed

aromatic

be

of

column

and

quality

plant

separating

kinds

Different

components

the

prinof

absorption.

separate

the

of

the

condensation

components

aroma

carriers

use

and

aroma

concentrated aroma

latter

rectification

kinds

entire

These

volatile

or

on

effect

recovery

different

could

more

the

the

the

proved

When

the

of

the

aroma

the

of

been

depending

some

and

poorly

particular

tration,

remain

which and

to

the

to

quality.

aroma

gradual

universal

therefore

adapted

known

with

compression

either

product

of

effectiveness.

have

position

Most

aromas

no

devised

equal

been

the

volatile

plants

combined

components

greatly,

highly

Improve

units.

vapour

designed

rectification,

volatile

However,

mechanical

to

usually

concentration cipclple

with

variously

I.e.

from

evaporatiretained In

concen-

In

his

exhaustive

paration

from

Sulc

5)

(It,

components sary

to

red,

which

survey

berries,

reports from

define In

that

fruit the

composition of

the

of

aroma

fruit

juice.

of

quality,

aroma

aroma

the

of

of

such as

fIavour

that

aroma, data

an aroma of

Is

the

extremely

necesrequiand

I.e.

on

on

the a

degree

sufficient

concentrate. same

In

degree

from each

Is

not and

of

that

determined

concentration yield

and

but

by

purity

of

other

standardization difficult

concentrate

aroma Is

components

not

the

considerably

Intensity,

the by

Indicaof

the

(6).

Numerous

authors

In aroma

compounds

the

Is

It

volatile

se-

fruit,

separate

total

of

that

aroma

evaporation

1:100,

differ

of

pome

quantitative

e.g.

mechanical the

the

follows

which means an aroma

degree

tors

can

the

concentrates

concentrates

quality

It

the q u a l i t y

words,

concentration In

of

to

Juice

on

and p o o r l y

concentration,

Indicator other

highly

and

successfully,

of

depends

the m i x t u r e

dynamics

fruit

In order

degree

turn

the

juice

qualitative of

of

drupe

have

technological

been

which

interested

occur

process

of

in

in

the

different

concentrated

changes phases

juice

of

pro-

duction. In o r d e r

to

tion

recovery

and

fectively, The

has

been

method

of

gas

distillation,

mentioned

certain

method

used

for

of

the

this

combined

samples

extraction

disadvantages

operations

the

separa-

operating

must

c h roma t o g r a p h y u s u a l l y

such

are

analytic

for is

be

purpose with

ef-

used. so

methods

components.

preparation

as

a plant

compounds

chromatography

aroma

certain There

whether aroma

frequently

gas

identifying

The

of

a suitable

method most

far of

determine

of

sample

to

and

be

presupposes

1»287

81,186,171, 53 105,106,77

4, 3

5I

=90

4=116 5I

5, 3

«206

« 7 . 6-35 »120 «8,7 «8.

6-155

79,108,107, 77,91 165,180,91 111,112,83, 45,58 85,114,113, 97,81,53 97,171,186, 141,73

1110

JI

10,9=S

125,126,97, 53,45

10. C H ^ S ^ - G H g O H

1118

5I

11,10"121

128,111,113, 97,95,45

11.

CH^S^-CHgOSi ( C H 3 )3

1239

¿I11>9.129

111,200,185, 97,45

12.

^S^C(0)CH3

1085

5l

13,12=-31

111,126,83, 43,39

13.

^S^ch(OH)CH3

1054

5lHt13=1l6

85,128,113, 110,84,45

14.

^S'-^CH

1160

5l14f12-75

185,111,200, 73,45

N

0Si(CH 3 ) 3

121

The study of volatiles compositions of the samples 1-4 showed that all four model systems hare produced a number of common compounds. In Fig.3 two chromatograms of samples 1 and 2 are given. The chromatograms were obtained in the same GC conditions using capillary column coated with 0V-101 as stationary phase. These chromatograms allow to see that both of the model systems contain a great number of the same compounds that also was proved by the GC and GC-MS analysis as described above. In addition we have investigated the volatile substances produced by model system without amino acids only from xylose and cysteine. The GC-MS results obtained allowed to estimate the substances have been formed in this two-components system. These compounds are asterisked in Table 3. They are present in samples 1-4. The comparison of the volatiles compositions of samples 1-4 gives a possibility to clear up the role of the substances common for all samples in the formation of meat flavour of model systems under study. Some furanes and thiophenes are particularly important for meat flavour because most of these compounds possess cooked meat aroma jjl9]» Some of found compounds possessing green,butter-like,vegetable-like, coffee and another food-like odours contribute to the characteristic cooked meat odour of model systems. All aroma compounds can be separated on three groups: aliphatic compounds,thiophenes and furanes. 2,3-Butanedione and 2,3-pentanedione were found in the samples 1-4 and in model system of xylose/cysteine. These substances possess a butter-like odour and are important both as potential contributors in meat aroma and as possible precursors of mercaptoketones (Table 3). The mercaptoketones are generated by the reaction of ì

: I *

S

la 1 . ! *

! [

!

a ^

-•-- «

i 1 'es 1 ! ¡J

^

1

«1 S ' »! •

j

! :; a1

5 ~ £

Ci

I

I

T

c*-

I1 to 3

Pig.3«

Chromatograms of concentrates of model systems with meat aroma (samples 1 and 2) obtained from bakery yeast autolysate (A) and bovine plasma (B). Glass capillary column with 0V-101 (50 m x 0,32 mm, film thickness 0,5 jum);50o-4°/min-250°. Peak numbers correspond with those in Table 3*

1?.3

Table 3.Volatile compounds identified in four model systems with meat flavour. Retention Peak (Figure 3) index in prog, temperature

Compound

Aliphatic compounds 2,3-Butanedione * Mercaptoethanal* 2,3-Pentanedione * 2-Mercaptobutan-3-one 3-Mercaptopentan-2-one * 2-Mercaptopentan-3-one * 1-Mercapto-1-methylthioethane 3-Methylthiopropanal

1 2 5 6 15 16 19 20

630 650 727 745 875 880 899 903

Thiophene derivatives 2-Methylthiophene * Tetrahydrothiophen-3-one 3-Mercaptothiophene 2-Methyltetrahydrothiophen-3-one 2-Pormylthiophene 2-Methyl-3-mercaptothiophene 2-Ac etylthiophene 2-Methyl-4-mercaptotetrahydrothiophen-3-one ( two isomers) 2-Methyl-5-founylthiophene 3-Methyl-2-foimylthiophene 2-Methyl-5-acetylthiophene

7 21 25 26 30 34 36 38 39 40 42 43

782 930 960 968 998 1038 1070 1084 1096 1100 1109 1118

Furane derivatives 2-Me thylte trahydro furan-3-one * Furfural Purfuryl alcohol 2-Methyl-3-mercaptofuran * 2-Me thyl-4-mercapt ofuran 2-Methyl-3-mercapto-4,5-dihydrofuran Purfuryl mercaptan 2-Methyl-3-furylsulfide Purfurylmethylsulfide 2-Methyl-5-acetylfuran

124

3 9 11 12 13 17 18 24 27 33

710 806 838 849 853 885 890 947 976 1021

Table 3 cont'd (2-Methyl-3-furyl)methyldisulfide

44

1133 1148

Bis(2-methyl-3-furyl)disulfide *

45 47 49

(2-Me thyl-3-furyl)-(2-methyl-4,5-dihydro-3-furyl)disulfide

50

(2-Methyl-3-furyl)furfuryldisulfide Bis(2-me thyl-4,5-dihydro-3-furyl)disulfide

51 52

1544 1558 1598

Bis-furfuryldisulfide *

53

1607

2-Me thyl-3-oxa-8-thiabicyclo/3,3,0/-1,4octadiene Furfuryldiaulfide

1170 1509

ducts of cystine with 2,3-butanedione [ 7 3 and in products of thermally degraded cysteine and cystine [23,24!. The formation pathways of thiophene derivatives in the JJaillard reaction were discussed in the number of papers [5.12,23,25]. For the first time the 2-methyl-3-mercaptothiophene and two isomers of 2-methyl-4-mercaptotetrahydrothiophen-3-one were found by us in model systems (samples 1-4) and in reaction products of xylose and cysteine. These three substances have a meat-like odour and may be important constituents of meat flavour. Twenty derivatives of furan were identified in samples 1-4 (Table 3). Thio-derivatives of furan are of great importance as the components of meat flavour. Mercaptofurans and their disulfides are the key compounds of meat aroma [11,14,193« Furthermore, these compounds have extremely low odour threshold values. For instance, the odour threshold of bis(2-methyl-3-furyl )disulfide was found to be 2 parts in parts of water [12]. 2-Methylfuranethiol-3 and its disulfide are major components of model systems volatiles (see Fig.3,peaks 12 and 49). Probably, these substances may be responsible for meat flavour of model systems under study. Earlier 2-methylfuranethiols and some difuryldisulfides were found in reaction products of 4-hydroxy-5-methyl3(2H)furanone with hydrogen sulfide [11], in products of degraded thiamine [12], in volatile components of a yeast extract [131, in a model system obtained by refluxing a water mixture of cysteine/thiamine/hydrolyzed vegetable protein (carbohydrate-free) [14]. Bis(2-methyl-3-furyl)disulfide was identified also by us in volatile components of Maillard reaction of a bakery yeast autolysate with xylose [15]. Probably, 2-methylfuranethiols can arise from reaction of 2-methyldihydro and 2-methy11etrahydrofuran-3-ones with hydrogen sulfide. Similar reaction of furfural or 4-hydroxy-5-methyl-3(2H)furanon with hydrogen sulfide is known [11,26]. Furfural and substituted furanons are formed during the xylose decomposition [4-6,10]. Oxidation of mercapto containing compounds leads to the disulfides mixture. Seven disulfides with methyl, furyl, furfuryl and thienyl groups were found in our model systems. These compounds possess a meat-like and coffee-like aroma;they are significant contributors in meat flavour. Thus, the investigation of model systems with meat aroma obtained by heating of hydrolysed yeast,animal or vegetable proteins with cysteine and xylose showed that independently on protein sources,a number of similar compounds including the key-compounds with meat aroma have been formed.

126

literature [1] Schutte,L.: Crit.Rev.Pood Technol.±( 1974)457-505. [2] Golovnya,R.V. and M.Rothes Nahrung 24(1980)2,141-154. [3] Schrodter.R.,and G.Wolm: Nahrung 24(1980) 2,175-183. [4] Ledl,F. and Th.Severin: Chem.Microbiol. Technol. Lebensm. 2(1973) 155-160. [5] Mulders, E.J.: Z.lebensm. Unters.-Forsch. 152(1973)193-201. [6] Scanlan, R.A., S.G. Kayser, L.M. Libbey, and M.E. Morgan: J.Agric. and Pood Chem. 21(1973) 673-675. [7] Hartman, G.J. and C.-T. Hos Lebensm.-Wiss.u.-Technol. 17(1984) 171-174. [8] Hartman, G.J.,J.D.Scheide, and C.-T. Ho: lebensm.-Wiss.u.-Technol. 17(1984) 222-225. [9] Hartman, G.J., J.T. Carlin, J.D. Scheide, and C.-T. Ho: J.Agric. and Pood Chem. 32(1984) 1015-1018. [10] Mussinan, C.J. and I. Katz: J.Agric. and Pood Chem. 21(1973) 1, 43-45. [11] Van den Ouweland, G.R.M., and H.G. Peer: J.Agric. and Pood Chem. 23(1975) 3,501-503. [12] Buttery, R.G., W.P. Haddon, R.M. Seifert, and J.G. Turnbaugh: J.Agric. and Pood Chem. 32(1984) 3. 674-676. [13] Ames, J.M., and G. Mac Leod: J.Pood Sei. 50(1985) 125-131. [14l Evers, W.J., H.H. Heisohn, B.J. Mayers, and A. Sanderson. In: Phenolic,Sulfur and Nitrogen Compounds in Food Plavors. ACS Symp.Ser. 26,(Ed.) Charalambous, G. and I.Katz. ACS Washington. 1976,p.184. [15] Golovnya, R.V., T.A. Misharina, V.G. Garbusov, and F.A.Medvedev: Nahrung 27(1983) 3, 237-249. ri6] Likens, S.T., and G.B. Nickerson: Am.Soc.Brew.Chem.Proc. (1964) 5-13. [17] Van den Dool, H., and P.D. Kratz: J.Chromatogr. 11(1963)463-467. [18] Garbuzov, V.G., T.A. Misharina, A.P. Aerov, and R.V. Golovnya: Z.Analit.Khim.40(1985)4, 709-720. [193 Misharina, T.A., S.V. Vitt, R.V. Golovnya, and V.M. Belikov: Z. Analit.Khim. 41(1986) 10, 1876-1881. [20] Oser, B.L., and R.I. Hall: Pood Technol. 25(1972) 1, 35-41. [21] Van Straten, S., PI. Vrijer, and J.C. Beauveser: Volatile Compounds in Pood. Krips Repto, Zeist 1977. r22] Lien, Y.C., and W.W. Nawar: J. Pood Sei. 39(1974) 911-918. [231 Shu, C.-K., M.L. Hagedom, B.D. Mookherjee, and C.-T. Ho: J, Agric. and Pood Chem. 33 (1985) 3, 438-446. [24^ Boelens, M., L.M. van der Linde,P.J. de Valois, H.M. van Dort, and H.J. Takken: J.Agric. and Pood Chem. 22(1974) 6, 1071-1076. [25l Shibamoto, T.: J.Agric. and Pood Chem. 28(1980) 2, 237-243. [26] Shibamoto, T.: J.Agric. and Pood Chem. 25(1977) 1, 206-208.

127

COMPARATIVE GTUuY OU CHICKEN FLAVüUii

SE LUCTED

0. ochliemann, G . ..'ölra and

SENSORY

ANiJ GAS C!-I.\'üi i. Vi'bGii.ÀPi ¡IC

UATrt oF

¿chrödter 1)

Vithin the last fow years no have dealt with possibilities and problems of tho simulation of chicken flavour, on thu basis of a thermal reaction between vegetable protein hydrolysates,

carbohydra-

tes, sulphur sources and slightly oxidized oils via tried to produce a chicken-like flavour

concentrate.

Lif course, the primacy of these investigations was to find relatxons between process and recepture parameters on one side and sensory properties of the simulates on tho other side in order to optimize the process of concentrate production. But additionally we got such an amount of material that we became able to use it for the search for relations between sensory and analytical, especially gas chromatographic results. At present time these studies are in an intermediate state so that we can present only some temporary results. Table 1: Statistical test plan for the optimization of concentrate production

-

process and recepture

x1 = peroxide value x 2 = amount of oil ( % in dry mass ) x 3 = C y s - H C I ( % in dry mass ) x 4 = Dry mass x 5 = Reaction time (min)

parameters

-«c

-1

0

2.4 0,5 0,22 16,2 6,2

30 50 6 10 1,25 2,00 30 40 20 30

+1

+

Pig.13. Chromatographic profiles of volatile amines of wine materials before and after champagne fermentation with yeast Saccharomyces vini £24]. A - temperature - 100°C, B - 150°C. S - the value proportional to the square of peak on the chromatogram. 8.Ethanolamine 1.Trimethylamine 9.Putrescine 2.Ethylaxnine 10.Is opropylac e tamide 3.Isobutylamine 11.Cadaverine 4.Methylbutylamine, isopentylamine 12.Not identified with I PEG =1582 PEG 5 * n-fentylamine 13.Not identified with 1 1623 6.Dibutylethylamine

192

pe variety on the composition of organic bases after champagne fermentation is insignificant indicating that the profile of amines is formed during fermentation only. The latter is illustrated with a diagram in Fig. 13 showing the changes in the content of some organic bases after 17 days of champagne fermentation at 10-15°. Unlike the aerobic fermentation with sherry races in the anaerobic champagne fermentation a tendency toward a decrease in highly volatile amines, such as methyl T ethyl-, propyl-, n-pentyl* dipropylamine and others is observed. On the other hand, such high-boiling compounds as ethanolamine, putrescine, N-isopropylacetamide are accumulated. The changes in volatile amine composition depends on complex biochemical transformations occurring in the course of growing of yeast cells responsible for the technological champagne fermentation. The results of these studies allow to conclude that the qualitative and quantitative composition of the volatile nitrogen-containing bases could serve as a specific test of the intensity of champagne fermentation and fermentation with sherry races in industrial conditions. The findings allow to relate the presence and type of changes of nitrogen-containing bases to the trend of the technological process and enable its control for production of high quality wine-making products. Bread baking In bread baking, studies on the composition of volatile organic bases related to wheaten bread making were conducted. It should be noted that formerly gas chromatography was used to study the volatile carbonyl compounds and changes of their composition in the course of wheaten bread baking, but no distinct relationship with technological stages was found [25, 26). The study of volatile amines has shown that this group of compounds is essential for bread flavour formation [26-30J. Accumulation of aroma forming substances occurs basically in the stage of sponge and dough fermentations and develops finally during bread baking as a result of biochemical transformations of proteins, carbohydrates, amino acids under the effect of flour and yeast enzymes, and in the final stage during baking at high temperature. Proceeding from the concept that the organic bases can serve as specific indicators of intensity of biochemical and microbiological processes, we studied the composition of volatile organic bases and its changes in the course of wheaten bread baking using the traditional sponge dough method. The amines were determined in the following technological stagesi after knf^lng

193

and the end of fermentation sponge and dough, proofing of dough and bread baking [30]. The amine chromatograms illustrating only three points of the bread making process are given in Pig. 14, i.e. sponge and the dough after fomentation and the bread (separately for the crumb and crust). It can be seen that each stage is characterized by its own chromatographic profile. In the chromatogram of volatile dough amines the number of peaks is the highest at the end of fermentation. As compared to sponge, a number of new substances emerge: the peak 12 disappears, the peak 18 and a number of others emerge. The quantitative relationship of amines also undergoes substantial changes in all stages, especially in that of dough making (Table 2). It emphasizes the importance of the processes occurring in the course of dough fermentation and gives an opportunity to vise the chromatographic amine profiles as indicators of the intensity of these processes. On the whole, about 100 organic bases were found by chromatography in all stages of bread baking, including 56 identified and 43 conventional ones. The duration of sponge and dough fermentation was found to affect the qualitative composition and quantitative relationship of amines in bread flavour condensates of crumb and crust. Proceeding from the concept that the chromatographic amine profiles contain information about the processes occurring in bread baking, the chromatograms obtained in stages of traditional wheaten bread production were used as the standard and the bread sample as the control in development of a new compact technological process of wheaten bread production using the yeast pour half-finished product (HFP) £29, 30] . The chromatograms of volatile amines in control dough (ill) and the dough on the pour half-finished product (I .) are presented in Fig. 15. It can be seen that the number of volatile amines on the chromatog*rams of the dough with HFP is much higher than on the chromatogram for control dough (compare No 18, 19, 25). Baked bread was of inferior quality to the control. The addition of 0,05% acetic acid to the pour half-finished product enabled normalization of the dough making stage. At the end of fermentation the amine chromatogram of the dough with HFP (II) was closer to the control OH). The organoleptic properties of bread made with HFP supplemented with acetic acid also improved and neared the control bread as it seen from Table 3. The organic bases, product of protein substance decomposition, can serve as indicators of the processes occurring at dough fermentation It is recommended to use the results of amine analysis in the stage of dough fermentation to determine the optimal parameters of wheat

Pig.14. Change of GC-profiles of volatile amines In the process of dough making and baking of white wheaten bread £}0j.

195

Pig.15« Volatile amines of wheaten dough prepered on pour half-finiahed product (H.P.P.) [30]. I - Dough on H.P.P., II - Dough on H.P.P. + 0,05#CH.jC00H, III - Dough prepered with traditionaly method (control).

196

Table 2 Quantitative relationships (% rel.) of some volatile organic bases of sponge, dough and wheaten bread (column with ApL at 100°) Sponge at the end of fermentation

Sough at the end of fermentation

Methyl-, ethyldimethyl-, trimethylmethylethyl-

48,5

30.1

24.7

21.5

Propyl-cyclo-pentylTrimethylpyrazine

1,5

1.0

0.9

5.1

2,3-dimethylpyrazine

1,4

0.4

4.3

9.6

Dimethylisopentylethyl-n-butyl-

6,2

Methyl-n-pentylN-ethylpyrrole propyl-sec-butyl-

6,0

Diethyl-sec-butyldi-sec-butylmethyl-sec-heptyl-

2,6

Methyl-sec-butyldimethy1-cyclo-hexyldimethyl-n-heptyl-

1,4

5.0

14.9

22,6

1.8

A M I N E

Ethylisopentyl^-picoline Pyrrolidine isopentyldiisobutyl-

Bread crumb crust

2,4

6.0

0.6

11,6

197

Table 3 Organoleptic evaluation of white wheaten bread prepared from pour half-finished product (HFP)

P A R A M E T E R

Dough from HFP

Dough from HFP + 0,05% CH,C00H

Control dough (ordinary method)

Odour (w.f. • 0,8)

1.6

2.8

3.2

Taate (w.f. - 0,8)

1.6

2.8

3.2

Total organoleptic

11.2

15.9

16.1

evaluation* •evaluation was carried out on 8 parameters 20 point system taking into account weight factors(w.f.)

half-finished product ripening in developing new progressive techniques of bread, roll and bun production. In conclusion it should be noted that, according to the findings, the research into the composition of volatile amines in foodstuff prodution, including fermentation, is promising. The chromatographic amine profiles used for control of traditional technological processes and purposeful search of new ones allow to ensure high organoleptic properties of the final foodstuffs. The thermodynamyc approach to flavour research of textured foodstuffs as a research of thermodynamically nonequilibrium systems of self-coordinated reactions, producing volatile substances is promising fruitful.

198

Literature £1]] Kolb, B.: Angewandte Gas-Chromatographie, 15. Perkin-Elmer, Überlingen, 1972. [2j Vitenberg, A.G. and. B.V. Ioffes Gasovaya Ekrftraktsiya in Khromatograficheskom Analize, Khimiya,Leningrad, 1982« [3] Golovnya, R.V.: in Prikl. Kromatografii, K.I. Sakodynskii (ed.), Nauka, Moscow, 1984. [4] Golovnya, R.V.s Talanta, (1987) 1, 51-60. [5] Talyzin, V.V., V.Ya. Anisimov, 0.1. Yakovleva, I.A. Mischarina and H.V. Golovnya: J. Analit. Chimii, ¿2, (1987), 2076-2079. [6] Uischarina, I.A., H.V. Golovnya and S.V. Vitt: Prikl. Biokhim. 1 llikrobiol., 21. (1985), 107-110. £7j Svetlova, N.I., Golovnya R.V f , I.L. Zhuravleva, D.N. Grigoryeva and A.L. Samusenko: Nahrung, 2£ (1985), 143-151. [8] Uischarina, I.A., S.V. Vitt and R.V. Golovnya: Biotechnologiya, 2 (1987), 210-216. [9] Golovnya, R.V., I.L. Zhuravleva and S.G. Kharatyan: in Letuchie Biologicheski Aktivnya Soedineniya Biogennogo Proishozhdeniya, M. Telitchenko and A. lanbiev (eds.), MGU, Moscow, 1971. [10] Golovnya, R.V., I.L. Zhuravleva and S.G. Kharatyan: J. Chromatog., Ü (1969), 262-268. fll] Brooks, J.B. and W.E. Moore: Can. J. Microbiol., .Ijj (1969),433-437. [12] Ihacker, L. and J.B. Brooks: Infect. Immun., £ (1974), 648-653« [13] Dunn, S.R., N.L. Simenhoff and L.G. Wesson: Anal. Chem., £8 (1976), 41-46. (143 Larsson, L., P.A. Mardh and G. Odham: Acta Pathol. Microbiol. Scand., 86B (1978), 207-213. [15J Brooks, J.B., D.S. Kellogg, Jr. M. E. Shepherd and C.C. Alley: J. Clin. Microbiol., H (1980), 52-58. [16] Davis, T.Y. and N.J. Hayward: J. Chromatog., ¿01 (1984), 11-15. [17] Brondz, I. and I. Olsen: J. Chromatog., ¿22. (1986), 3.67-411. [18] Golovnya, R.V., I.L. Zhuravleva, M.B. lerenina, A.N. Polin and V.A. Grushina: Biotechnologiya, £ (1985), 51-58. [19] Golovnya, R.V., M.B. lerenina and I.L. Zhuravleva: Prikl. Biokhim. i Mikrobiol., 22 (1986) 2, 217-225. [20] lerenina, M.B., B.V. Golovnya and I.L. Zhuravleva: Biotchnologiya, i (1986), 35-40. [21] Golovnya, R.V., M.B. lerenina and I.L. Zhuravleva: Abstr. II Wartburg Aroma Symosium, 1987. [22] Morina, G.V. and M.S. Umansky: Prikl. Biokhim. i Mikrobiol., 2J_ (1987) 2, 275-280.

199

[23] Kishkovskii, Z.N., L.P. Palamarchuk, E.V. Golovnya and I.L. Zhuravleva: Prikl. Biokhlm i Hikrobiol.,¿6 (1980) 3, 446-459. [24] Volodarskaya, N.S., L.V. Palamarchuk, Z.N.tfishkovokii,I.L. Zhuravleva and 1I.B. Terenina: Tezisy v Veesoyuznoi Konferentsii po Analiticheskoi Khimii Organicheskikh Soedinenii, Nauka, Moscow, 1984. [25] Sothe, II.: Handbuch der Aromaforschung. Aroma von Brot. AkademieVerlag, Berlin, 1974. [26] Golovnya, E.V., N.G. Enikeeva, I.L. Zhuravleva and A.S. Zjuzko: Nahrung, 18 (1974) 2, 143-156. [273 Zjuzko, A.S., N.G. Enikeeva, I.L. Zhuravleva and E.V. Golovnya: Izvestiya VUSOV, Pitshevaya Technologiya, 2 (1973), 161-164. [28] Zjuzko, A.S., N.G. Enikeeva, E.V. Golovnya and I.L. Zhuravleva: Prikl. Biokhim. i Mikrobiol., 10 (1974) 3, 443-449. [29} Kichaeva, T.I., N.G. Enikeeva, L.I. Pushkova, E.V. Golovnya, I.L. Zhuravleva and M.B. Terenina: Izvestiya VUSOV, Pitshevaya Technologiya, (1984), 101-103. [30] Kichaeva, T.T., N.G. Enikeeva, I.L. Zhuravleva and E.V. Golovnya: Prikl. Biokhim. i Mikrobiol., 2^ (1987) 3, 418-425.

200

POTENTIAL MEANS FOR IMPROVING THE FLAVOUR OF ALCOHOLIC BEVERAGES Lalli Nykanen 1 ^

In the manufacturing of alcoholic beverages, the fermentable drates in the mash are converted

by yeast

carbohy-

to alcohol and carbon di-

oxide. Although the processes are well understood in the alcohol industry, some problems occasionally appear which demand special investigations.

One

of

the

most

common

problems

is

the

occurrence

of

an

off-flavour in highly rectified alcohol. The compounds responsible for the off-flavour generally are present in very low concentrations therefore, important

may

be difficult

question

to remove

by

is, how effective must

means

of

and,

distillation.

An

the spirit distillation be

for the rectified spirit to be used in the production of the beverages of vodka types.. One must keep in mind that many vodkas contain an easily recognized grain flavour. Other vodkas, such as the Finlandia Vodka produced by the Finnish State Alcohol Company, however, are unflavoured and found to be free from all the flavour compounds typical of grain. In this case

even an

extremely

small

quantity

of

an off-flavour

is

easily detected. Therefore, in the alcohol beverage industry, the producers of grain spirits for top quality vodka have paid special attention to the rectifying process. There is no doubt that the flavour is the most important feature of an alcoholic their

beverage

palatable

and

that

properties.

many

beverages

Consequently,

are

it

produced

is not

mainly

surprising

for that

many researchers have been interested in the composition of the chemicals responsible for flavour and tried to find

relationships between

the

formation

composition

compounds

during

and

gustatory

fermentation,

compounds in distilled

properties. the

The

occurrence

beverages, and

of

the most

of

flavour

prominent

the composition of the

flavour

have been elucidated in our older review (41). Recently, more than 1300 flavour compounds occurring in beer, wine and distilled alcoholic beverages have been reviewed (23). Estimation of flavour by sensory analysis Sensory analysis has been used for estimation of the flavour characteristics for a long time, and it seems likely to remain the most important tool for improving beverages in the future despite the development of many good instrumental methods. Usually the terms used in commercial

Research Laboratories of the Finnish State Alcohol Company, Alko Ltd. POB 350, SF-00101 Helsinki, Finland

201

degustation are somewhat different the

flavour

profile

in

sensory

from those involved in determining

studies.

Although

there

are

a

great

number of publications in the literature dealing with sensory analyses of alcoholic beverages and special terminology, I have taken only one example by Ann Noble (24). She made a wide inquiry about the terms used in American wineries and on the basis of the responses, she proposed a list of analytical Fig.

1. Similar

terms which are shown in the wine aroma wheel

flavour

terminology

is used

to describe

the

in

flavour

characteristics in the beer (14) and whisky industries (37).

Fig. 1. Wine flavour wheel compiled by A. Noble (24). Origin of flavour compounds Since

the

60's

different

instrumental

methods,

particularly,

gas

chromatography, infra red spectrometry and mass spectrometry, have been widely used to identify flavour compounds in alcoholic beverages. The investigations indicate that all the flavour compounds of the beverages are not formed at the same phase of the manufacturing process. Principally,

the

flavour

compounds

of

sources. Some flavour compounds

the

beverage

originate

have been shown to occur

from in

three

free or

bounded form in the raw materials from which they are liberated during mashing

and

fermentation

(39.53).

A

great

number

of

the

flavour

compounds are formed during fermentation by yeast from sugars and other nutrients which are present in the medium. Particularly the yeast and the fermentation conditions may have a decisive effect on the composition of the flavour (18,19,40,43,44). With regard to distilled 202

bever-

ages, the distillation

procedure naturally

influences th e

composition

of the flavour by stripping both low boiling and high boiling compounds from the distillate. In many beverages the final flavour composition is achieved only after maturation. During the maturation process, some new compounds are formed in slow chemical reactions, while some other compounds disappear

(6,32).

Furthermore, a number

of

the compounds

are

liberated by alcohol from the wooden barrels used for the maturation (18,20,28,32,33). In fact, there are many possibilities to improve the flavour by changing the manufacturing conditions. By tasting and smelling different beers, wines, whiskies, cognacs and rums, one can easily find out that there are differences in flavours between the different brands. Grapes as a source of terpenic compounds The flavour of wine is known to involve a vast number of terpenic compounds.

It

has

been

shown

that

many

volatile

compounds

originally

present in grapes contribute varietal characteristics of the grapes to wines, thus enabling wines made from individual

cultivars to be dif-

ferentiated by analytical methods (31,34-36,52-54) . Many of these grape compounds are monoterpene alcohols and oxides which seem to be transferred more or less unchanged into the wine. An interesting finding is that only a portion of terpenes occur in a free form while others are bound

in

isolate

the

grapes

glycosidic

as

glycosides.

derivatives

from

Williams Muscat

(39,53,54) was

grapes

and

able

confirm

to

their

structure by analytical methods. They found that the precursors in both Muscat

of Alexandria

and

Riesling

grapes

were not

simply

g-D-gluco-

sides, but a complex mixture of g-rutinosides and B-O-a-L-arabinofuranosyl-B-D-glucopyranosides of several monoterpene alcohols. The pattern and concentration dependent

of

free

terpene compounds

on the mechanism by which

in grapes and wines

the compounds are

are

formed. In an

acidic medium, glycosides are hydrolyzed by the acids to sugars and the terpene

alcohols,

but

enzymes

that

can accomplish

the hydrolysis

in

grape juice also occur in grapes. Because substantial amounts of grape monoterpenes seem to be tied up in the fruit as glycosides or as flavourless

polyols,

they

form

a potential

reserve

of

flavour

in

wine

making. Flavour contribution of fermentation Most of the compounds formed during fermentation are volatile. Although the term "volatile compound" is a rather diffuse one, generally speaking all the compounds occurring in alcoholic beverages can be grouped according to whether or not they are distilled along with the alcohol and

water

carbonyl

steam.

Among

the

volatile

compounds

compounds, alcohols, monocarboxylic

there

acids

and

are

aliphatic

their

esters, 203

nitrogen and sulphur containing compounds, hydrocarbons,

terpenic com-

pounds, and heterocyclic and aromatic compounds. The major part of the non-volatile extract of the alcoholic beverages consists of unfermented sugars,

di-

and

tribaslc

carboxylic

tannic and polyphenolic substances

acids,

coloured

substances,

and

(23).

Because esters are numerically the largest group of flavour

compounds,

their formation has been thoroughly investigated (17-19,10,41,43,44). A possible

mechanism

used

for

illustrating

the

formation

of

esters

in

fermentation is based on investigations performed by NordstrOm (15).

THE FORMATION OF ESTERS OF ALIPHATIC MONOCARBOXYLIC ACIDS

By activation of monocarboxylic acida: R-COOH + ATP + CoA~SH

>

R-CO~$CaA + AMP + PPj + H j O

(t)

>•

R-CO~SCoA + NADH 2 + C 0 2

12)

F r o « 2 - o x o adda by oxidative decarboxylation: R-COCOOH + NAD + Co»~SH

From intarmadiataa of long chain monocarboxylic add lynthana: Ml+Z Biotin CO?

HJ, C - C O - S C o A

R—CO—SCoA +

HjC-CO~SCoA ^

HoC-CO-SCoA I COO"

+ 2NADH Z

(3a)

> • R - C H j - C H y C O - S C o A + CoA-SH + 2 NAD + C 0 2 + HjO

(3b)

Eitara a n formed by alcoholjreii of acyl-CoA compounda: R-CO~SCoA + R'OH

R-COOR' + CoA~SH

(4)

Fig. 2. Scheme for the fatty acid ester synthesis

(15).

According to the mechanism described in Fig. 2, acyl-coenzyme-A tions as the key compound

in the biosynthesis

mentation yeast produces acyl-CoA in cells either through the tion of

fatty

acid

or

through

the oxidative

func-

of esters. During decarboxylation

acid. These two mechanisms mainly differ in their capacity to

fer-

activaof

keto

utilize

ATP, the former requiring ATP and the latter not. Furthermore, in the ester synthesis as well as in the fatty acid synthesis, the lengthening of

the

carbon

bonds with

chain of

acyl-CoA

in

the the

acid

moiety

enzyme

occurs

complex,

so

that

bringing

two

malonyl-CoA more

carbon

atoms into the chain of the acid. The final step is the cleavage of the enzyme from the complex. In the presence of alcohol, the reaction produces an ester, whereas when water fatty

acid.

acetyl-CoA,

The

metabolic

therefore,

number of carbon atoms.

pathway

is present, in

yeast

the result cells

is a

beginning

from

leads to esters whose acid moiety has an In fact, esters having an even carbon

free even

number

regularly appear as primary components in the ester fractions of wines and distilled alcoholic beverages.

2CA

Particular attention has also been given to the ester formation by different yeasts. Hansenula anomala and Candida krusei yeasts, for example, have been found

to produce more ethyl acetate than do

Saccharo-

myces cerevisiae, Schizosaccharomyces pombe and Pichia raembranaefaciens (38).

On the other hand, of these five yeasts, Hansenula anomala and

Candida krusei have been found to form the lowest amounts of the ethyl esters of octanoic, decanoic and lauric acids (25). We investigated the ability of strains of Saccharomyces cerevisiae and S. uvarum yeasts to produce acetates of isopentyl and phenethyl alcohol and ethyl esters of the Cg

- C 1 2 fatty acids in semiaerobic sugar fermentations, perform-

ing the fermentations with 57 strains of Saccharomyces cerevisiae and three

strains of

S. uvarum

yeasts

(18,21).

The yeast

strains of

S.

cerevisiae were found to produce more isopentyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and phenethyl acetate than do S. uvarum

yeasts.

Furthermore,

we

were

able

to

show

that

the

distri-

bution of the fatty acid esters between the yeast cells and the fermentation medium is dependent on the chain length of the acid part of the esters. Both of the acetates, isoamyl acetate and phenethyl

acetate,

and ethyl hexanoate appear solely in the medium, whereas ethyl octanoate and decanoate are present in both the medium and the cells. Ethyl laurate was found only in the cells. The distribution of esters between the medium

and

the yeast

cells seem

to be dependent

upon

the yeast

species. The S. uvarum strains appear to retain relatively more of the total amount of ethyl octanoate and decanoate in the cells than do the S. cerevisiae strains. The esters are liberated from the yeast cells by distillation

and, hence,

the quantity of the esters amounts

in dis-

tilled beverages can be regulated by performing the distillation in the presence or absence of the yeast.

The effect of oxygen on the formation of esters Aerobic conditions are known to have a significant effect on the formation of esters. NordstrOm (15) concluded that aerobic conditions for a fermentation solution restrict the formation of isopentyl acetate and ethyl

hexanoate

Bertrand amounts

(7) of

in

aerobic

esters

in

fermentations

by

conditions

cause

fermentations

S.

cerevisiae.

the

performed

formation with

According of

to

differing

different

yeasts.

Bertrand reported that S. elllpsoideus and S. oviformis in a strictly anaerobic

fermentation produce eight times more isopentyl acetate and

five times more ethyl hexanoate

than in a semi-aerobic

fermentation,

whereas Schizosaccharomyces liquefaciens produces isopentyl acetate and ethyl hexanoate approximately in the same amounts under anaerobic and semi-aerobic conditions. The formation of isopentyl acetate by Saccha romycodes ludwlgil declines to a third when shifting from semi-aerobic to

anaerobic

Kloeckera

fermentation.

apiculata

was

Of

found

the

yeasts

used

to

produce

the

by

Bertrand

highest

levels

(7). of

205

Fig. 3. The formation of esters in semi-aerobic and anaerobic sugar fermentation by Saccharomyces cerevisiae yeast. isopentyl acetate but only in semi-aerobic fermentation; the yeast does not produce it at all in anaerobic fermentation. We found that the fermentation by a S. cerevisiae wine yeast, obtained from Geisenheim, produced under strictly anaerobic conditions considerably more of isopentyl acetate than in semi-aerobic conditions (18,21). Furthermore, we showed that twice as much ethyl hexanoate and octanoate as well as phenethyl acetate was formed in anaerobic fermentation than in semi-aerobic fermentation. It is also worth mentioning that clearly less ethyl laurate is produced in a fermentation performed under anaerobic conditions. Considerably less ethyl palmitate and an unsaturated ester, ethyl 9-hexadecenoate, also are produced by this wine yeast under anaerobic conditions than under semi-aerobic conditions. The effect of alcohols on the formation of esters

While investigating the effect of added alcohols on the formation of esters, we found that the addition of 2-methylpropanol and 3-methylbutanol to the fermentation mixture.^ interrupted the synthesis of fatty 206

Fig. i|. R e l a t i o n s h i p b e t w e e n the a m o u n t s o f i s o - p e n t y l a l c o h o l a c e t a t e f o r m e d by S . c e r e v i s i a e y e a s t in s u g a r

and

fermentation.

Fig. 5. R e l a t i o n s h i p b e t w e e n the a m o u n t s o f p h e n e t h y l a l c o h o l a c e t a t e f o r m e d b y S ^ c e r e v i s i a e y e a s t in s u g a r

and

fermentation.

a c i d s so that no a c i d s h i g h e r than a c e t i c a c i d w e r e f o r m e d . Thus, 2-methylpropyl added

acetate

alcohols.

This

and

3-methylbutyl

raised

the

acetate

possibility

were

that

formed

the

the

formation

of

i s o p e n t y l a c e t a t e d e p e n d s u p o n the f o r m a t i o n of i s o p e n t y l a l c o h o l 4 a n d 5) a n d , c o r r e s p o n d i n g l y , phenethyl

alcohol

in

sugar

only

from

(Figs

p h e n e t h y l a c e t a t e u p o n the f o r m a t i o n

fermentation

(17).

The

gas

chromatogram

of in

207

Fig.6. The f l a v o u r c o m p o u n d s French cognac

(see text) of S c o t c h w h i s k y

fused silica capillary column Fig. 6

illustrates

esters having

the

composition

even carbon atoms

ester

(peak

Scotch whisky. in

Scotch

under

whisky

of

in

an

extract

myristate

acid (peak

decanol

(peak

flavour

of

that

composition

60)

in

about

probably

equal

the

conditions. such

57),

addition

in

as

compounds

may

characteristic

determined

in

of

of

is

fermentation

occurrence

ethyl to

55) a n d h e x a d e c a n o l

is

whisky.

Ethyl

(peak 59) a n d p a l m i t i c

concentrations

result

The

esters,

these

from

the a c i d m o i e t y are p r o m i n e n t .

l a r g e a m o u n t s of the u n s a t u r a t e d e t h y l is

semiaerobic

carboxylic

smell

The

and

(17).

o c c u r r e n c e of p a l m i t o l e i c a c i d e t h y l e s t e r ethyl

(upper)

(lower) gas c h r o m a t o g r a p h e d on a 50 m O V - l O l

of

laurate

the

long

chain

typical of

the

long

52)

responsible

Scotch

French

malt

cognac

for

and

ethyl

alcohols,

whisky.

(22)

can

the The be

wort chain

tetra-

(peak 5 8 ) , is c o n s p i c u o u s . The be

of

palmitoleate

the

(peak

The acid

fatty

stearinelike the found

flavour to

be

q u a l i t a t i v e l y s i m i l a r to that for S c o t c h w h i s k y . The role ents

of

that

yeast plays

alcoholic

in e s t a b l i s h i n g

beverages

is

notable;

the

basic

flavour

flavour

constitu-

compositions

e r a g e s p r o d u c e d from d i f f e r e n t r a w m a t e r i a l s a r e s i m i l a r if the 208

of

bev-

same

15 1« 17 19,20

y

U.

J LujiilLaJuX

2345678 9 10„11 12 13 1« 1Î 16 17 19,20

llj

d

Fig. 7- Gas chromatograms of the aroma extract of Finnish berry wine of a sherry type (upper) and that of a Spanish sherry (lower). The compounds are listed in Table 1. Column: A 50 m OV-lOl fused silica capillary column (17). yeast is used. Some twenty years ago we compared the flavour

composi-

tions of Spanish sherry to that of Finnish berry wine of a sherry type. When

both

beverages

are

produced

by a

solera

method,

using

a

yeast, the compositions are remarkably similar even though the was made rants. similar

from grapes and

Recently, study

high

the Finnish berry wine

resolution

(17). The

gas

chromatograms

was made

chromatography (Fig

was

7) indicate

Jerez sherry

from

cur-

used

that

for

a

although

some clear quantitative differences can be found, the qualitative

com-

positions are similar.

com-

pounds,

excluding

It is interesting to note

aliphatic

fusel

alcohols,

that among the

phenethyl

alcohol

is

the

largest component in both the Spanish sherry and Finnish berry wine of sherry

type.

Diethyl

succinate,

ethyl

lactate

and

2,3-butanediol

are

209

Table 1. Contents (mg/L) of flavour compounds in a genuine Spanish sherry and a Finnish berry wine of sherry type (17). Peak

Compound

Spanish.sherry

no

Finnish berry wine

Ethyl propionate

0.268

Isopentanol

not measured

0.040

2,3-Butanediol

1. 306

0.602

2,3-Butanediol

0.563

0.068

Ethyl butyrate

0.382

0.066

Ethyl lactate

3.804

2.862

1.324

0.556

2,3-Pentanediol

(tent.)

Ethyl isovalerate

0.294

traces

3-Hexen-l-ol

0.238

n.d.

10

Hexanol

1.076

n.d.

11

Isopentyl acetate + 0.277

gamma-butyrolactone

0.795

12

Ethyl hexanoate

0.558

0.108

13

Benzyl alcohol

0.717

n.d.

14

Ethyl 2-hydroxyisohexanoate

0 . 830

0.024

15

Phenethyl alcohol

26.640

2.636

16

Diethyl succinate

11.488

1.628

17

Ethyl octanoate

0.259

0.240

18

Lactone (MW 146)

0.147

0.016

19

Lactone (MW 146)

1.031

20

Hydroxy acid ethyl ester

21

Lactone

22

5-Butyl-4-methyl-dihydro-

23 24

Ethyl decanoate

n.d.

traces 0.637

0.269

0.047

(3-H)-2-furanone

0.166

traces

Lactone

0.615

0.084

0.034

0.096

none detected

also prominent components in both beverages, even though the amounts in Spanish sherry are higher than in the Finnish berry wine. Consequently, sherry yeast produces the same aroma components irrespective of whether grapes or berries are used as the raw material. The role of carbonyl compounds The most volatile aroma fraction of alcoholic beverages has been to be composed

of carbonyl

compounds. While investigating

the

found occur-

rence of carbonyl compounds in completely fermented medium, Suomalainen 210

(40)

showed

keto

acids

that a c e r t a i n r e l a t i o n s h i p and

the

structurally

c a n be s h o w n

corresponding

to e x i s t

amino

acids,

between

aldehydes

a n d a l c o h o l s w h i c h a r e l i s t e d in T a b l e 2. T a b l e 2. K e y c o m p o u n d s in the f o r m a t i o n o f a l c o h o l s a n d a m i n o a c i d s yeast

by

(40).

Alcohols

Aldehydes

Keto

acids

Amino

Ethanol

Acetaldehyde

2-Ketopropionic

Glycol

Glyoxal

3-Hydroxy-2-ketopropionic

acid

acids

Alanine Serine

acid

1-Propanol

Propionaldehyde

1-Butanol

Butyraldehyde

2-Methyl-l-

Isobutyraldehyde

2-Ketoisovaleric

2-Methylbutyr-

2-Keto-3-methyl-

2-Ketobutyric

acid

2-Aminobutyric acid

acid

Valine

propanol 2-Methyl-lbutanol

aldehyde

valeric

Isovaleraldehyde

3-Methyl-l-

Isoleucine

acid

2-Ketoisocaproic

acid

Leucine

butanol Hexanal

1-Hexanol

3-Phenyl-2-keto-

Phenethyl alcohol

propionic

Tyrosol

Phenylalanine

acid

3-(4-hydroxyphenyl)2-ketopropionic

Tyrosine

acid

Tryptophol

Tryptophan

Suomalainen

with

his

co-workers

(40,42-45)

a l d e h y d e s a n d k e t o a c i d s are e s s e n t i a l w e l l as been

for

the

formed

Consequently,

f o r m a t i o n of

in the

the

yeast

keto

acids

y e a s t cells c o u l d be found

was

fusel a l c o h o l s . cells, which

they were

After

in the f e r m e n t a t i o n

to

to be

beverages.

While

investigating

when

the

action

p h a s e . The t o t a l a l d e h y d e c o n t e n t found

the

as

have

medium. in

the

although

the

fermentation.

performed

to v a r y

the

formation

of

levels in a l c o carbonyl

com-

(29,30) f o u n d that the h i g h e s t a l d e h y d e level is r e a c h e d

fermentation

In a s s a y s

that

content

pounds, Radler during

show

present

solutions,

T h e r e are s e v e r a l r e a s o n s for the v a r i a t i o n of a l d e h y d e holic

to

the c o m p o u n d s

transfer found

y e a s t is able to m e t a b o l i z e k e t o a c i d s d u r i n g Aldehyde

able

for the a m i n o a c i d s y n t h e s i s

with

f'rom 6

to

of y e a s t

300 y e a s t s

(49,50),

190

litre.

mg

is

in

the m o s t

vigorous

seems to d e p e n d u p o n the y e a s t per

the It

is

aldehyde

used.

content

interesting

to

was note

211

that b a k e r ' s y e a s t , w i l d - t y p e y e a s t a n d b r e w e r ' s y e a s t d i f f e r ly in their a l d e h y d e For

a

given

related

yeast

to

the

to their r e s p i r a t o r y

production due

strain,

activity

the

of

amount

its

of

acetaldehyde

pyruvate

c i e n c y of n u t r i e n t

it

decarboxylase.

c o m p o s i t i o n m a y a l s o have a n e f f e c t on the c a r b o n y l

distinct-

capabilities. produces The

nutrient

formation.

A

i n the w i n e ;

m a t i o n of e t h y l a l c o h o l is d e l a y e d

this is b e c a u s e

to

keto

acids

are

fusel

alcohols

acids.

present

aldehydes,

in

by

the

With

(55.56). W i t h a d e f i c i e n c y o f

fermentation

abundance,

deamination

2-keto acids,

amino

and

are

conditions

acids

are

in

decarboxylation.

The

foramino

clearly

which

converted

rise

the

a c i d s , the p a t h from the c a r b o n s o u r c e to the fusel a l c o h o l s is diverted

defi-

s u b s t a n c e s in the f e r m e n t a t i o n of g r a p e s g i v e s

to i n c r e a s e d l e v e l s o f a l d e h y d e s

is

amino

instead

to

precursors

of

f o r m e d as i n t e r m e d i a t e s

in b o t h

pro-

c e s s e s (1) . In a d d i t i o n to the b i o c h e m i c a l alcohols,

oxidative

Strecker

d a t i o n of

fatty acids

may

reactions

described above, oxidation

degradation

also

produce

of

amino

aldehydes

acids,

and

of

autoxi-

in a l c o h o l i c

bever-

a g e s . In s h e r r i e s , for e x a m p l e , e t h y l a l c o h o l is s l o w l y o x i d i z e d b y air into acetaldehyde; although

the

Of course, extent. wine

this r e a c t i o n takes p l a c e d u r i n g the s o l e r a

oxidation

of e t h y l

the a l d e h y d e

The

presence

solutions

has

l e v e l in w i n e s

of

vicinal

been

alcohol

to a c e t a l d e h y d e

phenols

produces

a

alcohol

strong

to It

accelerate

oxidant,

to a c e t a l d e h y d e .

t i o n of a l d e h y d e s

in w i n e s

and

much more complex

phenomenon

the

distilled

than

merely

some

in

model

oxidation

of

ethyl

the a u t o x i d a t i o n peroxide,

i n v o l v i n g the

findings

slowly. to

phenols

hydrogen

reactions

process,

place

during aging

that

probably

These

takes

tri-hydroxy

is s u p p o s e d

t h e n i n i t i a t e s a n u m b e r of o x i d a t i o n of e t h y l a l c o h o l

increases

di- and

shown (51).

generally

show

beverages

that

during

the o x i d a t i o n

of

which

oxidation the

forma-

aging

is

of a l c o h o l s

a by

air. a m o n g the c a r b o n y l s

and

g e n e r a l l y c o n s t i t u t e s m o r e t h a n 90 % of the t o t a l a l d e h y d e c o n t e n t .

Be-

Acetaldehyde

is f r e q u e n t l y

the m a j o r c o m p o n e n t

c a u s e of the low b o i l i n g p o i n t

(21 °C) a c e t a l d e h y d e

together with water and alcohol ubiquitous.

The

total

aldehyde

0.1 to 15

mg/litre

beverages.

The u n p l e a s a n t

beverages

can

be

for a c e t a l d e h y d e

is

distilled

into distillates and, therefore, content

has b e e n r e p o r t e d

in most b e e r s , a n d up to 300 m g / l i t r e

it

to v a r y in

25 p p m beverages

without (13).

difficulty.

Rectification

to some

extent.

The

distilled

sensory

decreases

Because of

is

from

s m e l l o f l a r g e q u a n t i t i e s of a c e t a l d e h y d e

recognized

l e v e l in d i s t i l l e d

is e a s i l y

in

threshold

the

aldehyde

the

low

alde-

h y d e c o n t e n t of the r e c t i f i e d a l c o h o l u s e d for the p r o d u c t i o n o f v o d k a , the

aldehyde

litre

or

content

less.

of

different

Relatively

large

w h i s k y , c o g n a c , b r a n d y a n d rum.

212

vodkas

generally

aldehyde

According

amounts

to G u y m o n

is

some

can (2,3)

10 m g

be the

found

per in

aldehyde

content

of

commercial

b e i n g some high

as

brandy

distillates

are

generally

11 mg/1 at 50 % a l c o h o l , but a c e t a l d e h y d e

261

mg/1

have

been

found

in

a

low

low,

the

mean

concentrations

quality

brandy

(5)-

as For

c o m p a r i s o n , some a l d e h y d e c o n t e n t s in d i s t i l l e d b e v e r a g e s a r e l i s t e d in Table

3.

T a b l e 3- A l d e h y d e c o n t e n t in d i s t i l l e d a l c o h o l i c b e v e r a g e s Beverage

mg/1

American

whisky

Bourbon whisky whisky

(50 % a l c o h o l )

av.

43

-

60

20 10

-

36

Irish whisky

20

-

70

Scotch

20

- 110

19

-

63

- 308

Canadian

Wine

blended

distillate

Brandy

(23).

55

av. 105

Cognac

In a d d i t i o n

to

saturated

aldehydes,

a potential

effect

of some

unsat-

u r a t e d a l d e h y d e s o n the f l a v o u r of a l c o h o l i c b e v e r a g e s s h o u l d be into

consideration.

graphy

the

Canadian acrolein,

low

beer

boiling still

which

responsible

When

has

K a h n et compounds

product, a

al.

in a h e a d

they

pungent

(10) d e t e r m i n e d

found

odour

fraction

acrolein.

and

a

by g a s

distilled

They

lachrymatory

is p r o d u c e d e i t h e r b y b a c t e r i a from g l y c e r o l , or g l y c e r o l is

2,4-Heptadienal,

2-Methyl-2-propenal

2-Hexenal,

2-Methyl-2-butenal,

cis-,

dehydrated

3-Methyl-2-butenal

2-Octenal,

2,4-Nonadienal, 2-Nonenal,

1-Cyclohexene-l-carbaldehyde

2,4-Decadienal,

1,2,3-Trimethyl-3-cyclo-pent

-1-acetaldehyde

reacts

lasses spirit

easily

with

Recently,

distilled

three we

trans,

trans-,

trans,

trans-,

trans-,

alcohol

found

(8).

trans-,

2-Methyl-2-pentenal

triethoxypropane.

acrolein.

trans-,

2-Pentenal,

Acrolein

is

acrolein

trans-,

2-Heptenal,

trans-,

a

that

property,

on hot s u r f a c e s of the d i s t i l l a t i o n c o l u m n a n d c o n v e r t e d into

Acrolein

from

suggested

for the " p e p p e r y " smell in some w h i s k i e s . P r o b a b l y

T a b l e t. U n s a t u r a t e d a l d e h y d e s i d e n t i f i e d in c o g n a c

taken

chromato-

trans,

molecules

trans-,

to

form

1,1,3-triethoxypropane

from m a s h c o n t a i n i n g

glycerol. Our

in

1,1,3a

mo-

experiments

213

showed

that

the

acrolein

content

quickly

decreases

in

the

spirit,

whereas 1,1,3-triethoxypropane

seems to be fairly stable. Acrolein has

been found to be present also

in cognac and rum. A number of unsatu-

rated aldehydes identified in cognac (8) are listed in Table 4. Vicinal diketones The vicinal diketones, 2,3-butanedione

(diacetyl) and 2,3-pentanedione,

are ubiquitous flavour components of wine and distilled alcoholic

bev-

erages. Both diketones are prominent flavour compounds; diacetyl has a particularly special position in beverages threshold,

and

therefore

its

because of its low

formation and occurrence

sensory

should be

dis-

cussed briefly. The

mechanism

solution was suggested

for

which

by

2,3-butanedione

settled only

recently.

2,3-butanedione

is

The

involves

formed

metabolic the

in

a

fermentation

pathway

formation

of

originally

acetolactate

and its degradation to 2-hydroxy-3-butanone, but this mechanism has not been

confirmed.

On

the

contrary,

it

has

been

shown

(26)

that

2,3-

butanedione is not formed by oxidation of 2-hydroxy-3-butanone in yeast fermentation. According to Suomalainen and Ronkainen (46),

2,3-butane-

dione is formed outside the yeast cell by spontaneous decomposition of 2-acetolactate which is formed in the yeast cells. The

2-acetolactate

is an intermediate in the biosynthesis of 2-ketoisovalerate, which is a precursor

of

valine,

leucine

and

2-mettiylpropanol

formation

in

the

yeast cell. A plausible alternative mechanism for the formation of Table 5- Content of 2,3-butanedione in wines and distilled beverages

(23).

Beverage

2,3-Butanedione mg/1

White wine

0.05 - 3.40

Rose wine

0.11 - 1.24

Red wine

0.02 - 4.06

Brandy

0.07 - 3.0

Cognac

0.10 - 0.31

Scotch whisky

0.09 - 0.32

Rum

0.03 - 4.4

Vodka

0.01 - 0.10

2,3-butanedione has been also presented oxidative 214-

decarboxylation

of

(9). Its key step involves

2-acetolactate

to

2,3-butanedione.

an The

concentrations of vicinal diketones, 2,3-butanedione and dione, in wines and distilled beverages vary widely

2,3-pentane-

(Table 5). Postel

and Gtlvenc (27) reported that the average concentration of 2,3-butanedione was 0.42

mg/1 in wines, with no differences between the quality

classes. The average content of 2,3-butanedione in red wines of various European origins is 1.46 mg/1. LeppSnen et al.

(12) investigated

the

occurrence of vicinal diketones in wines. They found that some 50 % of the total 2,3-butanedione in white wines and 25 % of its total amount in red wines is probably bound with sulphur dioxide. Scotch whisky and cognac contain an average of 0.16 mg of 2,3-butanedione

per litre. A

Martinique rum was found to contain as much as 4.4 mg/1. The sensory threshold for 2,3-butanedione has been reported to be 0.15 ppm in beer (13). The threshold for it in wine and distilled beverages such as whisky, cognac beer. The

observed

and

rum may

concentrations

cases to such an extent

be somewhat

seem

higher

to exceed

this

than

that

limit

that the butterscotch flavour of

2,3-butane-

dione should be recognisable in the samples. Also 2,3-pentanedione frequently

found

minor importance

in wine and distilled

beverages.

in

in some

However,

to the flavour because of its fairly low

is

it is of concentra-

tions and high sensory threshold. The effect of maturation on the flavour of beverages Beverages contain also a number of minor compounds which appear only after

fermentation.

Maturation

is usually a necessary

stage

for

im-

proving the flavour of alcoholic beverages. It has been shown that the amounts of aldehydes, esters, acids, furfural as well as non-volatile tannins, colouring matter and solids increase

(6) in the whisky dis-

tillate during ageing. In addition to the formation of these compounds which

are

progressively

produced

in

slow

chemical

reactions

during

ageing, a number of degradation reactions take place in the wall of the cask. Approximately 2 % of the water and alcohol pass yearly

through

the inner wall of the cask; while doing so they initiate the hydrolysis of hemicelluloses

and

large

lignin

compounds.

The

constant

flow

of

water and alcohol through the interstices and cells in the hardwood of oak effectively extract these hydrolysis products into the distillate. The

picture

shows

that

(Fig.

8) made

by

the oak has been

means

of

changed

scanning

electron

to a completely

dead

microscopy hard

wood

(20). Therefore, it cannot transport water in the stem, and is an excellent material for casks. We attempted to elucidate this slow process by investigating the compounds liberated from oak chips by alcohol (20) It

is

effect

interesting on

the

to see

amount

of

that total

the

content

extract.

reached with a solvent which contained

of

The

alcohol maximum

has

a

marked

efficiency

was

60 % alcohol, which is a 215

Fig 8. S c a n n i n g e l e c t r o n m i c r o s c o p y v i e w of oak c h i p

(20).

Fig. 9. Gas c h r o m a t o g r a m o f v o l a t i l e c o m p o u n d s l i b e r a t e d by a l c o h o l from oak chips at 60 % a l c o h o l . A f u s e d s i l i c a

capillary

c o l u m n of 50 m w e r e u s e d ; see the c o m p o u n d s in T a b l e

6.

u s u a l l y a l c o h o l s t r e n g t h d u r i n g m a t u r a t i o n . W h e n the c o m p o s i t i o n o f e x t r a c t w a s a n a l y s e d in d e t a i l by m e a n s o f h i g h r e s o l u t i o n g a s t o g r a p h y a n d gas c h r o m a t o g r a p h y 6),

some

acidic

compounds

f o r m a t i o n of a c e t a l s ,

216

esters

were and

combined with mass spectrometry found,

which

lactones.

probably

Ethyl

esters

(Table

catalyze of the

the

chromathe

dicar-

Table 6. Carboxylic acids and some non-acidic components liberated from oak chips by alcohol

(20).

Peak Compound

Peak Compound

1

23 24

Undecanoic acid

25 26

Azelaic acid

2

3-Hexanol Valeric acid Hexanoic acid

5 6

1,1-Dimethoxyethane 2-Furancarboxylic acid

Cinnamic acid Laurie acid Tridecanoic acid

7 8

Unknown

27 28

Sebacic acid

Fumaric acid

29

Tetradecanoic acid

9 10

Heptanoic acid

30

Undecanoic acid

Succinic acid

31

Branched Pentadecanoic acid

11

Ethyl hexanoic acid

32

Branched hexadecanoic acid

12

Limonene

13 14

Benzoic acid

33 34

Benzenetricarboxylic acid

35 36

Branched hexadecanoic acid

15 16

Mesaconic acid Octanoic acid Phenylacetic acid 2-Hydroxybenzoic acid

Pentadecanoic acid Ferulic acid

37 38

Palmitoleic acid Branched heptadecanoic acid

Palmitic acid

17 18

Nonanoic acid

19

5-Butyl-4-methyl-2(3H)-

39 40

furanone cis

41

Heptadecanoic acid

5-Butyl-4-methyl-2(3H)-

42

Oleic acid

furanone trans

43 44

Stearic acid

20 21

Decanoic acid

22

3,4-Dimethoxyphenol

boxylic ified.

acids,

fumarie,

In addition

hydroxyoctanoic

succinic

to acids,

acid

Phthalic acid

Hexadecanedioic acid

and

azelaic

cis- and

gamma-lactone

(whisky

the alcoholic extract of oak chips. Webb rence of the whisky

lactones

acid,

trans-

in Cabernet

were

isomers

lactone)

of

were

also

detected

(11) has reported the Sauvignon wines,

ident-

3-methyl-4in

occur-

and

Guymon

are

widely

and Crowell (4) detected them in brandies. Flavoured alcoholic beverages Essential

oils

or

alcoholic

extracts

of spices

and

herbs

used for flavouring alcoholic beverages. On a manufacturing scale,

the

isolation of flavour compounds is carried out by percolating the spices with an alcohol-water mixture followed by distillation of the solution, usually under reduced pressure. The composition of the flavour

extract

is dependent upon the alcohol concentration and the equipment. We have

217

3 I

1J

iOiiiSJIJl

jfi\fl B1l)j 14 15 16 18 19 20

25^27

ii if"i H

¡30

33 3-1

i ji i

Hill

11

jJuj-ULAU.

ilVUi

v.'

i

!IMii

1 liUj

Fig. 10. H i g h r e s o l u t i o n gas c h r o m a t o g r a m s of the f l a v o u r

compounds

d e t e r m i n e d in a F i n n i s h (upper) a n d a n E n g l i s h (lower)

gin:

1 a-thujone, 2 a-pinene, 3 camphene, 4 sabinene, 5 B-pinene, 6 6-myrcene, 7 a-phellandrene, 8 3-carene, 9 a-terpinene, 10 g - c y m e n e , 11 l i m o n e n e ,

12 t r a n s - o c i m e n e ,

14 t e r p i n o l e n e , 15 l i n a l o o l , a c e t a t e , 18 4 - t e r p i n e o l ,

16 c a m p h o r ,

17

13

y-terpinene,

4-terpinonyl

19 t r a n s - p i p e r i t o l e t h y l

20 4 - e t h o x y - 1 - g - m e n t h e n e ,

ether,

21 n e r o l , 22 c i s - p i p e r i t o l

ethyl

e t h e r , 23 b o r n y l a c e t a t e , 24 a - c u b e b e n e , 25 a - c o p a e n e , 26 3 - e l e m e n e , 27 a - g u r j u n e n e , 28 B - c a r y o p h y l l e n e , 29

B-sequlphel-

l a n d r e n e , 30 a - h u m u l e n e , 31 y - m u u r o l e n e , 32 6 - c a d i n e n e 33 a - g u a i e n e , 34 S - c a d i n e n e 2, 35 Y " e l e m e n e 36 e t h y l

and angelica

in the f l a v o u r

root

(47,48)

f l a v o u r i n g gin. A m o n g the c o m p o u n d s

compounds occurring

because

in

b o t h h e r b s are

of a juniper berry distillate

lysed b y a g a s c h r o m a t o g r a p h i c m e t h o d , a - p i n e n e , s a b i n e n e , m y r c e n e w a s u s e d to d e t e r m i n e the f l a v o u r c o m p o u n d s in a n e t h e r - p e n t a n e angelica

ones 218

being

root,

a

a-pinene,

total

of

64

3-carene,

juni-

used

a - t e r p i n e n e w e r e f o u n d in f a i r l y large q u a n t i t i e s . W h e n the s a m e of

B,

palmitate.

been especially interested per b e r r i e s

1,

/ germacrene

compounds

were

a-phellandrene,

found,

with

limonene,

for ana-

and method

extract

the

major

B-phellan-

drene and 2 - c y m e n e The gas chromatograms in Fig. 10 demonstrate the flavour composition of a sample of Silver Gin produced in Finland and that of an English gin. In this case the flavour was separated and concentrated using a liquidon a fused

silica

capillary column. A Total of 35 compounds were identified and

liquid extraction technique and gas chromatographed

deter-

mined quantitatively. The same compounds which were found in the juniper berry and angelica root extracts were confirmed

to be present

in

the Finnish product. When the chromatogram is compared to the next one which presents the flavour composition of an English Gordon Gin sample, the similarity is remarkable, although some differences in the concentrations of the compounds may appear. These gin analyses provide a good example how successful sensory analyses made by a well trained professional panel can be confirmed by means of instrumental methods.

LITERATURE 1. Âyrâpâa, T.: On the formation of higher alcohols by yeasts and its dependence on nitrogenous nutrients. Kem. Tidskr. (1971) 79-90. 2. Guymon, J. F.: Composition of California commercial brandy distillates. Amer. J. Enol. Viticult. 21 (1970) 61-69. 3. Guymon, J. F.: Brandy distillates. Composition and quality. Wines and Vines ¿2 (1971) 27-29. 4. Guymon, J. F. and E. A. Crowell: GC-separated brandy components derived from French and American oaks. Amer. J. Enol. Viticult. 2J (1972) 114-120. 5. Guymon, J. F. and D. L. Wright: Collaborative study of the direct bisulfite method for the determination of aldehydes in brandy and wine spirits: American Society of Enologists - AOAC joint report. J. Assoc. off. analytic. Chemists 51 (1972) 566-569. 6. Baldwin, S. and A. A. Andreasen: Congener development in bourbon whisky matured at various proofs for twelve years. J. Assoc. off. analytic. Chemists. 57 (1974) 940-950. 7. Bertrand, A.: Utilisation de la chromatographic en phase gazeuse pour le dosage des constituants volatils du vin. Thèse, Faculté des Sciences de l'Université de Bordeaux 1968. 8. ter Heide, R., P. J. de Valois, J. Visser, P.P. Jaegers, and R. Timmer: Concentration and identification of trace constituents in alcoholic beverages, in "Analysis of Food and Beverages. Headspace Techniques". G. Charalambous, ed., Academic Press, New York, 1978 pp. 249-281. 9. Inoue, T: Influence of temperature on formation of acetohydroxy acids by brewer's yeast. Rep. Res. Lab. Kirin Brewery (1974) 25-27.

17

10. Kahn, J. H., E. G. Laroe, and H. A. Conner: Whiskey composition: identification of components by single-pass gas chromatogra-

219

p h y - m a s s s p e c t r o m e t r y . J. F o o d Sei.

(1968)

395-400.

11

K e p n e r , R. E., A. D. W e b b , a n d C. J. M u l l e r : I d e n t i f i c a t i o n of 4-hydroxy-3-methyloctanoic acid gamma-lactone (5-butyl-4m e t h y l d i h y d r o - 2 - ( 3 H ) - f u r a n o n e as a v o l a t i l e c o m p o n e n t o f o a k w o o d - a g e d w i n e s of V i t i s v i n i f e r a v a r . " C a b e r n e t S a u v i g n o n " . A m e r . J. Enol. V i t i c u l t . 2 J (1972) 1 0 3 - 1 0 5 .

12

L e p p ä n e n , 0 . , P. R o n k a i n e n , T. K o i v i s t o , a n d J. D e n s l o w : A s e m i a u t o m a t i c m e t h o d for the gas c h r o m a t o g r a p h i c d e t e r m i n a t i o n of v i c i n a l d i k e t o n e s in a l c o h o l i c b e v e r a g e s . J. Inst. B r e w i n g (1979) 2 7 8 - 2 8 1 .

13

M e i l g a a r d , M . C . : A r o m a v o l a t i l e s in beer: P u r i f i c a t i o n , f l a v o u r , t h r e s h o l d a n d i n t e r a c t i o n . In: D r a w e r t , F. ed, G e r u c h - u n d Geschmackstoffe. Internationales Symposium aus Anlass des E i n h u n d e r t j ä h r i g e n B e s t e h e n s der F i r m a H a a r m a n n & R e i m e r G m b H , H o l z m i n d e n , B a d P y r m o n t , G e r m a n y , 2-4 O c t o b e r , 1974, V e r l a g H a n s C a r l N ü r n b e r g 1975 pp. 2 1 1 - 2 5 4 .

14

M e i l g a a r d , M . C . , C.E. D a l g l i e s h , a n d J.F. C l a p p e r t o n : P r o g r e s s t o w a r d s a n i n t e r n a t i o n a l s y s t e m of b e e r f l a v o u r T e r m i n o l o g y . Am. Soc. B r e w . C h e m . ¿ 7 (1979) 4 2 - 5 2 .

15

N o r d s t r ö m , K.: S t u d i e s o n the f o r m a t i o n o f v o l a t i l e e s t e r s i n fermentation with brewer's yeast. S v e n s k kem. T i d s k r . (1964) 5 1 0 - 5 4 3 .

16

N y k ä n e n , L.: A r o m a c o m p o u n d s l i b e r a t e d from oak c h i p s a n d w o o d e n c a s k s by a l c o h o l . In: N y k ä n e n , L. a n d P. L e h t o n e n eds, F l a v o u r R e s e a r c h of A l c o h o l i c B e v e r a g e s . Instrumental and Sensory A n a l y s i s . P r o c e e d i n g s of the A l k o S y m p o s i u m o n F l a v o u r Res e a r c h of A l c o h o l i c B e v e r a g e s , 13-15 J u n e , 1984, H e l s i n k i , F i n l a n d , F o u n d a t i o n for B i o t e c h n i c a l a n d I n d u s t r i a l F e r m e n t a t i o n R e s e a r c h , V o l 3, H e l s i n k i , F i n l a n d 1984 pp. 1 4 1 - 1 4 8 .

17

N y k ä n e n , L.: F o r m a t i o n a n d o c c u r r e n c e of f l a v o u r c o m p o u n d s in w i n e a n d d i s t i l l e d a l c o h o l i c b e v e r a g e s . A m e r . J. E n o l . V i t i cult. 2 1 (1986) 8 4 - 9 6 .

18

N y k ä n e n , L. a n d I. N y k ä n e n : P r o d u c t i o n of e s t e r s b y d i f f e r e n t y e a s t s t r a i n s in sugar f e r m e n t a t i o n . J. Inst. B r e w i n g , (1977) 30-31.

76

83.

19

N y k ä n e n , L. a n d I. N y k ä n e n : R u m flavour. In: P i g g o t t , J.R. ed, F l a v o u r of D i s t i l l e d B e v e r a g e s : O r i g i n a n d D e v e l o p m e n t , E l l i s H o r w o o d L t d . , C h i c h e s t e r , 1983 pp. 4 9 - 6 3 .

20

N y k ä n e n , L., I. N y k ä n e n , a n d M. M o r i n g : A r o m a c o m p o u n d s d i s s o l v e d from oak c h i p s by a l c o h o l , in " P r o g r e s s in F l a v o u r R e s e a r c h 1984". P r o c e e d i n g s of the 4 t h W e u r m a n F l a v o u r Res e a r c h S y m p o s i u m , D o u r d a n , France. -9-11 M a y 1984, J. A d d a e d . , E l s e v i e r S c i e n c e P u b l i s h e r s B . V . , A m s t e r d a m 1985 pp. 3 9 9 - 3 4 6 .

21

N y k ä n e n , L., I. N y k ä n e n a n d H. S u o m a l a i n e n : D i s t r i b u t i o n o f e s t e r s p r o d u c e d d u r i n g sugar f e r m e n t a t i o n b e t w e e n the y e a s t cell a n d the m e d i u m . J. Inst. B r e w i n g , 83, (1977) 3 2 - 3 4 .

22

N y k ä n e n , L., P. S a v o l a h t i a n d I. N y k ä n e n : F i r s t e x p e r i e n c e s w i t h HRGC-FT-IR analysis of flavour compounds in distilled alcoholic b e v e r a g e s . In: B e r g e r , R.G., S. Nitz a n d P. S c h r e i e r , eds. T o p i c s in F l a v o u r R e s e a r c h . P r o c e e d i n g s o f the I n t e r n a t i o n a l Conference, Freising-Weihenstephan April, 1-2 1985, H. E i c h o r n , M a r z l i n g - H a n g e n h a m , G e r m a n y 1985 pp. 1 0 9 - 1 2 3 .

23

N y k ä n e n , L. a n d H. S u o m a l a i n e n : A r o m a of B e e r , W i n e a n d D i s t i l l e d A l c o h o l i c B e v e r a g e s . In: R o t h e , M. e d , H a n d b u c h d e r A r o m a F o r s c h u n g , A k a d e m i e - V e r l a g , B e r l i n a n d D. R e i d e l P u b l i s h i n g

22
•

X o rH TD

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