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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
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-
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
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