View
5
Download
0
Category
Preview:
Citation preview
The multiple role of polyphenol chemistry
in coffee associated with quality attributes
24th ASIC Conference, Costa Rica, 13.11.2012 Arne Glabasnia, Imre Blank, Federico Mora, Valérie Leloup, Josef Kerler
Nestlé PTC Orbe
AGENDA
• Introduction
• Coffee polyphenols as quality markers for green coffee
• Coffee Polyphenols and aroma
• Coffee Polyphenols and taste
• Coffee Polyphenols and health
• Conclusion
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
(Poly)phenols
Flavanols
Isoflavones (genistein,
daidzein)
Flavonols (e.g. quercetin)
Anthocyanins
Catechins Pro(antho)cyanidins
Flavanones
e.g. hesperidin
Flavonoids
Phenolic acids (e.g ferulic
acid, caffeic acid,
chlorogenic acids)
Ellagic acid/ellagitannins
The family tree of (poly)phenols
Antioxidants
Others (BHT, Vit C)
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Chlorogenic acids are the major phenols in coffee
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Quinic acid Intermediate from the shikimic acid cycle
Chlorogenic acids Esters of quinic acid with hydroxycinnamic acids
Cinnamic acids Common metabolites in plants
OH
OH
OH
OH
O
OH
R
OH
O
OH
OH
OH
OH
O
O
OH
RO
OH
O
OH
OH
O
OH
R
O
OH
OH
O
OH
O
OH
R
O
O
OH
OH
OH
O
OH O
R
Diversity of chlorogenic acids in coffee
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
3-caffeoyl quinic acid 4-caffeoyl quinic acid 5-caffeoyl quinic acid
coumaric acid dimethoxycaffeic acid trimethoxycaffeic acid sinapic acid
RO
O
OH
RO
O
OH
OCH3
OCH3
RO
O
OCH3
OCH3
OCH3
RO
O
OCH3
OCH3
OH
O
OH
OH
O
OH
O
OH
OH
OH
OH
OH
O
O
OH
O
OH
OH
OH
OH
O
OH
O
OH O OH
OH
3-feruoyl quinic acid 4-feruoyl quinic acid 5-feruoyl quinic acid
OH
O
OH
OH
O
OH
O
OH
H3CO
OH
OH
OH
O
O
OH
O
OH
OCH3
OH
OH
O
OH
O
OH O OH
OCH3
Diversity further increased by presence of diesters
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Di-Caffeoylquinic acids
1C,3CQA
1C,4CQA
1C,5CQA
1F,3FQA
1F,4FQA
1F,5FQA
3F,4FQA
3F,5FQA
4F,5FQA
1C,3FQA
1C,4FQA
1C,5FQA
3C,4FQA
3C,5FQA
4C,5FQA
1F,3CQA
1F,4CQA
1F,5CQA
3F,4CQA
3F,5CQA
4F,5CQA
+ all homo- and heterodiesters containing
- coumaric acid
- dimethoxycaffeic acid
- trimethoxycaffeic acid
- sinapic acid
More than 100 different Di-Chlorogenic acid
3,4-dicaffeoyl quinic acid 3,5-dicaffeoyl quinic acid 4,5-dicaffeoyl quinic acid
OH
O
O
OH
O
OH O OH
OH
O
OH
OH
OH
O
OH
O
O
OH
O
OHOH
O
OH OH
OH
OH
O
O
O
OH
O
OH
OH
O
OH
OH
Coffee phenols as quality
markers for green coffee
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Chlorogenic acids as quality markers for blend
• To differentiate between Robusta and Arabica
• To calculate blend of unknown samples
– LC-DAD (Mullen et al. 2011)
– by NIR (Haiduc et al.)
– by NMR (Wei et al. 2010)
– by LC/MS direct infusion (Garrett et al. 2012)
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Arabica
Robusta
Haiduc et al, unpublished Garrett et al, 2012
Chlorogenic acids as markers for coffee origin
• CGA used in as indicator of origin (Alonso-Salces et al, 2009)
- to classify Robusta coffees from Cameroon, Indonesia, Vietnam
- to classify Arabicas from America and Africa
• No effect for origin for Robusta from Africa (Ky et al 2001)
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Robusta Arabica
Alonso-Salces, 2009 Alonso-Salces, 2009
Differentiation of cultivar by CGA content
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Monteiro et al (2012)
• Differentiation of cultivars by CGA profile sometimes possible
• Crop to crop variety for one cultivar bigger than from cultivar to cultivar
Chlorogenic acids as quality markers for post-harvest
treatment
• 17 brazilians cultivars analysed for CGAs, trigonelline, caffeine and sucrose
• In average higher CGA content in wet-processed coffee compared to semi-dry
• Trigonelline higher as well, sucrose lower, no effect on caffeine
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
0
1000
2000
3000
4000
5000
6000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
5-C
QA
[m
g/1
00g
]
semi-dry wet
(adapted from Duarte et al, 2010)
Chlorogenic acids in correlation with cup quality
• Correlation of CGA content with cup quality (Farah et al, 2006)
• The higher the CGA content the lower the cup quality
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Cup quality
Farah et al (2006)
Coffee phenols and their role in
coffee aroma
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Chlorogenic acids as aroma precursors upon roasting
Important aroma compounds in roasted coffee
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Semmelroch et al. (1995)
CH2
OH
OCH3
O
OH
OCH3
CH3
OH
OCH3
OH
OCH3
4-vinylguaiacol
guaiacol
4-ethylguaiacol
vanillin
Phenolic impact compounds Compound Arabica Robusta
(E)-beta-damescenone 260000 270000
furfurylthiol 110000 170000
MMBF 37000 33000
MBT 27300 27700
3-isobutyl-2-methoxypyrazin 16600 2400
homofuraneol 15000 12000
furaneol 11000 5700
2,3-butandione 3390 3190
4-vinylguaiacol 3200 8900
guaiacol 1700 11000
2,3-pentandione 1320 660
methional 1200 500
vanillin 192 644
2-ethyl-3,5-dimethylpyrazin 165 470
2,3-diethyl-5-methylpyrazin 95 310
sotolon 74 32
4-ethylguaiacol 32 362
abhexon 21 11
Dose-over threshold
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
0
20
40
60
80
100
0 10 20
Rela
tiv
e h
ead
sp
ace c
on
cen
trati
on
(%
)
DMS
Ethanethiol
FFT
MMBF
N-Methylpyrrole
2,3-Pentanedione
Significant losses in headspace concentration
of e.g. thiols, pyrroles occur within hours
Time (hours)
Role of chlorogenic acids in aroma staling
Mueller et al, 2007
Losses in headspace concentration
of FFT occur within minutes
Are chlorogenic acids involved in that degradation?
hydroxyhydroquinone
(HHQ)
(Müller et al, 2007)
Trapping of key odorants (thiols) by polyphenols via
oxidative coupling
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
The loss of 2-furfurylthiol during coffee storage is mainly due to the oxidative coupling
of the odorant to hydroxyhydroquinone (2), giving rise to the conjugates 9 and 10.
Reaction possible for intact CGAs but not found in coffee
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
catechol adduct
caffeic acid adduct
CQA adduct
Formed in model experiments Found in coffee brew
OH
OH
S
OOH
S
OOH
OH
S
OOH
OH
CH3
OH
OH
S
OOH
O
(Mueller et al, 2007)
S
Chlorogenic acids involved in coffee staling but not
exclusively
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
?
OSH
OSH
R
OS
radical inducedoxidation (C-radical)
RS
oxidation - director radical induced(S-radical)
N
N SO
SO
R
R
R
N
N
RR
N
N
R
nucleophilicaddition at melanoidins
OH
OH
S
O
SO
OH
OH
O
Onucleophilicaddition at chlorogenic acid
derivatives
+ .
+
+
reaction with aldehydes/
heterocycles
N
S
O
Hofmann &
Schieberle
(2002)
Müller &
Hofmann
(2005)
Munro et al.
(2003)
Milo et al.
(unpublished )
Coffee phenols and their role in
coffee taste
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
CGAs as precursors for tastants: lactones
• Lactone formation well known (Farah et al, 2005)
• Lactones have been identified as bitter compounds in coffee (Frank et al.
2006) giving pleasant coffee-like bitter taste
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Frank et al., 2006
Frank et al., 2006
Compound mg/l umol/l
3-O-caffeoyl-γ-quinide (2a) 13.4 40
4-O-caffeoyl-γ- quinide (3a) 12.1 36
5-O-caffeoyl-epi-δ-qunide (4a) 60.5 180
4-O-caffeoyl-muco-γ- quinide (5a) 11.2 30
5-O-caffeoyl-muco-γ- quinide (6a) 9.7 29
3-O-feruoyl-γ-quinide (2b) 13.7 39
4-O-feruoyl-γ- quinide (3b) 13.7 39
3,4-O-dicaffeoyl-γ-quinide 4.8 9.8
3,5-O-dicaffeoyl-epi-δ-quinide 24.9 50
4,5-O-dicaffeoyl-muco-γ- quinide (3a) 4.8 9.8
Bitter threshold
CGAs as precursors for tastants: phenylindanes
• Phenylindanes another class of bitter compounds formed from CQA degradation
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
HO OH
O
O
OH
OHOH
HOOC
HO OH
O
OH
HO COOH
HO
OH
HO OH
HO OH
H+
H
OH
OH
R1 OH
H3C
OH
OH
R1
HO
OH
OH
R1
HO
H
OHHO
R1 OH
H3C
HO OH
Interm.
H
OH
OH
R1 OH
H3C
HO
HO
5-Chlorogenic acid caffeic acid
quinic acid
4-vinyl catechol
phenylindanes
phenylbutanes
phenylbutenes
diphenylindanes
5-CQA caffeic acid vinylcatechol
phenylbutanes
phenylbutenes
phenylindanes
diphenylindanes
Compound mg/l µmol/l
Phenylbutanes 6 23
Phenylbutenes 39 145
Phenylindanes 9-40 32-148
Diphenylindanes 15-27 37-67
Bitter threshold
Frank et al., 2007 Frank et al., 2007
CGA as precursors for tastants: furan benzene diols
• Benzene diols are formed from catechols and furan derivatives in
model roast experiments (Kreppenhofer et al. 2010)
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
O
OH
O+
CH2
OCH2
+
H+
- H20
OH
OH
O
OH
O
OH O OH
OH OH
OH
R O
O
R
O
OH
OH
furfuryl alcohol
catechol 4-CQA
4-(furan-2-ylmethyl)benzene-1,2-diol
O
OH
OH
O
OH
OH
OH
O
OH
OH
CH3
O
OH CH3
OH
TC: 9.6 mg/L TC: 6.5 mg/L
TC: 5.7 mg/L TC: 7.5 mg/L
+
Kreppenhofer et al, 2007
Formation of bitter tastants upon roasting
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
0
20
40
60
80
100
120
green 110 90 70 50
Rel%
Roast degree
Roasting
Caffeine CQL DKP Phenylindane • Bitter precursor content
depends on blend
• Bitter compound formation
depends on roasting degree
• Kinetics are different for
different chemical classes
• Bitter quality also different
coffee-like
harsh
caffeine-like
metallic
Compound class Threshold for bitterness (umol/L)
Caffeine 750
Lactones 30-200
DKPs 190-4000
Phenylindanes 30-150
Benzenediols 100-800
Sensory analytical correlation
Profiling was carried out with an expert panel (n=12)
The basic
attributes...
• roasty
• bitter
• acid
The ‚subtle‘ aroma descriptors...
fruity-floral
red fruits, lemon, jasmine
green-vegetal
herbs, fresh vegetables
dry-vegetal
wood, malt, cereal
vegetal-humus
earthy, mushroom
cacao
roasted, cacao, dark chocolate
sweet
vanilla, caramel, honey
... describe the basic
properties of an
Espresso coffee
... describe the signature
aroma of an Espresso coffee
... are grouped based on
olfactive similarity
Baggenstoss et al, ASIC 2010
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
54 aroma and taste compounds were analyzed for the
present study
substance flavor quality substance flavor quality
1 methanethiol sulfur, garlic 28 2-acetylthiazole roasty, popcorn
2 dimethyl sulfide cabbage, sulfur 29 furfural grass, almond 3 dimethyl trisulfide sulfur, cabbage 30 furfuryl acetate -
4 furfurylthiol sulfur, roast 31 2,3,5-trimethylpyrazine roasty
5 3-mercapto-3-methylbutylformate catty 32 2-ethyl-3,6-dimethylpyrazine roasty, earthy 6 methional potato 33 2-ethyl-3,5-dimethylpyrazine roasty, earthy
7 3-methyl-2-butenethiol sulfur, amine 34 2-ethenyl-3,5-dimethylpyrazine roasty, earthy 8 2-methyl-3-furanthiol meat 35 2,3-diethyl-5-methylpyrazine roasty, earthy 9 acetaldehyde pungent, fruity 36 2-acetylpyrazine roasty
10 propanal solvent, pungent, fruity 37 2-isopropyl-3-methoxypyrazine pea, earthy 11 2-methylpropanal fruity, pungent 38 2-isobutyl-3-methoxypyrazine pea, earthy 12 2-methylbutanal fruity, cocoa 39 β-damascenone rose, honey 13 3-methylbutanal malty 40 sotolon maggi, curry 14 phenylacetaldehyde honey 41 furaneol caramel 15 hexanal grass 42 maltol caramel 16 2,3-butanedione buttery 43 3-CQA - 17 2,3-pentanedione buttery 44 5-CQA -
18 vanilline vanilla 45 4-CQA - 19 ethyl 2-methylbutanoate fruity 46 5-CQL bitter 20 ethyl 3-methylbutanoate fruity 47 4-CQL bitter
21 p-cresol medicinal, phenolic, smoke 48 5-FQA - 22 guaiacol smoke, medicine 49 4-FQA -
23 4-ethylguaiacol spice, clove 50 cyclo-Val-Pro bitter
24 4-vinylguaiacol spice, clove 51 cyclo-Ala-Pro bitter 25 N-methylpyrrole - 52 cyclo-Pro-Leu bitter
26 pyridine - 53 cyclo-Phe-Pro bitter
27 2-acetylpyridine popcorn 54 caffeine bitter
Baggenstoss et al, ASIC 2010
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Around 30 compounds exhibit strong correlation to
aroma quality
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
-1.0 -0.5 0.0 0.5 1.0
-1.0
-0
.5
0.0
0
.5
1.0
Comp1
Com
p2
R1
E1
E5
L1 L2
R2
R3
E4
E2
E6
L3
E3
CTn
dimethyl trisulfide
2,3-pentanedione
N-methylpyrrole
2-acetylpyridine
guaiacol
furaneol
methanethiol
dimethyl sulfide
furfurylthiol acetaldehyde
2-methylpropanal
2-methylbutanal
phenylacetaldehyde
hexanal
2,3-butanedione
pyridine
2-acetylthiazole
furfural
furfuryl acetate
2,3,5-trimethylpyrazine
2,3-diethyl-5-methylpyrazine
2-isopropyl-3-
methoxypyrazine
2-isobutyl-3-methoxypyrazine
p-cresol
4-ethylguaiacol 4-vinylguaiacol
3-methyl-2-
butene-1-thiol
2-methyl-3-furanthiol methional
sotolon
vanilline
25mL (Ristretto) 40mL (Espresso)
110mL (Lungo)
green-vegetal
vegetal-humus
cocoa fruity-flowery
sweet
roasty
bitter acid
dry-vegetal
No correlation with lactones
found for bitterness perception
Baggenstoss et al, ASIC 2010
Around 30 compounds exhibit strong correlation to the
sensory descriptors
sweet
roasty
dry vegetal
cocoa
bitter
vegetal-humus
green vegetal
acid
fruity-flowery
2-acetylpyridine
pyridine furfuryl acetate
phenylacetaldehyde
3-methyl-2-butene-
thiol
N-methylpyrrole
2-isopropyl-3-methoxypyrazine
2-methyl-3-furanthiol
4-ethylguaiacol
guaiacol
4-vinylguaiacol
dimethyl trisulfide
2,3-diethyl-5-methylpyrazine p-cresol
2-isobutyl-3-methoxypyrazine
2-methylpropanal
vanilline
2-acetylthiazole
hexanal
2-methylbutanal
methional
furfural
sotolon
furaneol
2,3-pentanedione
dimethyl sulfide
2,3,5-trimethylpyrazine
2-furfurylthiol
acetaldehyde
methanethiol
2,3-butanedione
Correlation found for aroma
compounds derived from CQA
breakdown with bitterness
perception
Baggenstoss et al, ASIC 2010
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Bitterness prediction model from aroma compounds
including those derived from CQA is very good
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Baggenstoss et al, ASIC 2010
Coffee phenols and their role for
health
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Polyphenols/flavonoids have been considered to
have an effect on health for many years
1936
1957
Albert von Szent-
Györgyi Nobel Prize in
Physiology or Medicine
(1937)
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
The importance of coffee polyphenols in human diet
Coffee
• 36. place in mg/100g
• 6. place per serving
• 1. place for daily consumption
(3-4 cups per day)
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
0 40 80 120 160
dark chocolate
blackberry
highbush blueberry
plum
cider apple
orange juice
green tea infusion
strawberry
grapefruit
raspberry
peach
broad bean
dessert apple
red wine
nectarine
black grape
pecan
apricot
black tea
pearepicatechincatechinprocyanidin B2procyanidin B3procyanidin B1procyanidin C1procyanidin EECEGCEGCGcyanidindelphinidinmalvidinpelargonidinpetunidinquercetinhesperidinnaringenin
(mg/100g fresh weight)
Scalbert et al, 2010
CQAs most contributors to polyphenol intake in French
adults
Scalbert et al, 2011
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
More and more reports on positive effects on health for a
moderate coffee consumption
• Robust inverse relation between regular coffee consumption, including
decaffeinated, and risk of type 2 diabetes based on meta-analyses of
epidemiological studies (van Dam 2006; van Dam and Hu 2005)
• Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2
diabetes mellitus: a systematic review with meta-analysis. (Huxley et al 2009)
• The use of green coffee extract as a weight loss supplement: a systematic
review and meta-analysis of randomised clinical trials. (Onakpoya et al 2011)
• Lipophilic antioxidants more neuroprotective than hydrophilic (e.g. lactones
(Chu et al 2009)
• High CQA coffees prevent oxidative damage (Hoelzl et al 2010)
• Antioxidant rich coffee reduces DNA damage (Bakuradze et al, 2011)
• CGA rich coffee induce chemopreventive phase II enzymes (Boettler et al.
2011)
• Coffee has positive effects to reduce cognitive decline (Abreu et al, 2011)
• ASIC session yesterday
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Antioxidant activity of green coffee comes mainly from
CGAs
• More than 100 coffee polyphenols have been already reported in the
literature by the scientific community (Clifford & Kuhnert )
Total Antioxidant Activity
by folin in%
CQA FQA di-CQA
• 80% of the total antioxidant activity in green coffee comes from the 9
main chlorogenic acid
OH
OH
OH
O
O
OH
O
OH
OH
OH
OH
OH
O
O
OH
O
OH
OCH3
OH
O
O
OH
O
OH O OH
OH
O
OH
OH
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
0
50
100
150
200
250
300
350
400
GC Light Medium DarkT
ota
l po
lyp
hen
ols
(µm
ol 3
CQ
A /g
gre
en c
offe
e d.
b.)
0
50
100
150
200
250
300
350
400
GC Light Medium Dark
An
tio
xid
ant
cap
acit
y
(µm
ol 3
CQ
A /g
gre
en c
offe
e d.
b.)
0
50
100
150
200
250
300
350
400
GC Light Medium Dark
An
tio
xid
ant
cap
acit
y
(µm
ol 3
CQ
A /g
gre
en c
offe
e d.
b.)
0
100
200
300
400
500
600
GC Light Medium Dark
An
tio
xid
ant
cap
acit
y
(µm
ol 3
CQ
A /g
gre
en c
offe
e d.
b.)
0
50
100
150
200
250
300
350
400
GC Light Medium Dark
To
tal p
oly
ph
eno
ls
(µm
ol 3
CQ
A /g
gre
en c
offe
e d.
b.)
0
100
200
300
400
500
600
GC Light Medium Dark
To
tal p
oly
ph
eno
ls
(µm
ol 3
CQ
A /g
gre
en c
offe
e d.
b.)
From 9 CGAs
From melanoidins
a)Total polyphenols by FOLIN
b) Antioxidant capacity by ABTS
Antioxidant activity in roasted coffee stays at high level but
is less explained by CGAs
Leloup et al, ASIC 2010
-150
-100
-50
0
50
100
150
0 10 20 30 40 50 60 70 80
retention time (min)
Abso
rptio
n
5mg/mL 325nm
ABTS
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
-200
-100
0
100
200
300
400
500
0 10 20 30 40 50 60 70 80
retention time (min)
Abso
rptio
n 5mg/mL
325nm
ABTS
CQAs diCQAs
FQAs
Antioxidant activity of roasted coffee derives from small
new peaks but mainly from a unresolved hump
Leloup et al, ASIC 2010
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
▼
*
*
*
● ●
●
▼
▼
*
CQA
Lactones
di-CQA
Caffeic acid moiety
*
CafTrp
Inte
ns
ity
Retention time (min)
5 10 15 20 25 30 35 40 45 50
▼
*
*
*
● ●
●
▼
▼
*
CQA
Lactones
di-CQA
Caffeic acid moiety
*
CafTrp▼
*
*
*
● ●
●
▼
▼
*
CQA
Lactones
di-CQA
Caffeic acid moiety
*
CafTrp▼
*
*
*
● ●
●
▼
▼
*
CQA
Lactones
di-CQA
Caffeic acid moiety
*
CafTrp
Inte
ns
ity
Retention time (min)
5 10 15 20 25 30 35 40 45 50
Precursor ion scan by LC/MS of a roasted coffee to detect
precursors of caffeic acid moiety
Leloup et al, ASIC 2010
Caffeic acid moiety largely present in unresolved hump
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Incorporation of chlorogenic acids into coffee melanoidins
Bekedam et al, 2007
Model roasting of 5-CQA at 200°C in dry state
0
20
40
60
80
100
120
0 10 20 30
g/1
00g
heating time in minutes
CQA content Folin response
RT: 0.08 - 38.21
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Time (min)
-5000
0
5000
10000
15000
20000
-5000
0
5000
10000
15000
20000
-5000
0
5000
10000
15000
20000
uA
U
-5000
0
5000
10000
15000
20000
RT: 4.22
AA: 756821.2310.391.46 14.37
5.30
4.0914.2311.02
12.173.62 15.17
4.76
3.17 15.9011.11 14.763.36 16.48 28.7517.452.62 6.38 12.68
RT: 15.98
MA: 905098
17.554.74
3.13 11.15 14.75
28.8928.4724.766.372.53 12.81
NL:
2.37E4
Channel B
UV
Genesis
NHW_1112
08_02_111
208161859
NL:
2.37E4
Channel B
UV
nhw_11120
8_04
NL:
2.37E4
Channel B
UV
nhw_11120
8_06
NL:
2.37E4
Channel B
UV
nhw_11120
8_08lactones
HPLC chromatogram from final reaction mixture Degradation of 5-CQA and Folin of reaction mixture
• 5-CQA is rapidly degraded in model roast mix at 200°C
• TPP by Folin of reaction mixture remains almost constant
• Lactones are formed but cannot explain loss of 5-CQA and Folin values
• A lot of minor peaks are detectable
• Chromatographic tools suitable?
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
C:\Xcalibur\data\Kaffee\111208c 09.12.2011 17:05:03 CQA + Sucrose 30 min
111208c #10 RT: 0.27 AV: 1 NL: 4.23E7
T: - c ESI Full ms [ 150.00-2000.00]
200 400 600 800 1000 1200 1400 1600 1800 2000
m/z
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Re
lativ
e A
bu
nd
an
ce
689.12
1025.15671.08 707.18
191.12
851.15
515.10
1007.11
1361.14
352.93
863.15 1187.20833.09497.07
255.191169.15
1343.17
1697.081523.141043.16
1679.25995.17 1859.27651.15471.10 807.06 1143.12881.11 1223.29 1996.90561.06 1736.08
Direct infusion into LC/MS of model roast of 5-CQA
Polymerization of CQA can be observed
CQA
CQL
DiCQA
Di-CQL
+174
QA-H2O
+162
CA-H2O
+174
QA-H2O +162
CA-H2O
OH
OH
OH
OH
O
OH
OH
OH
O
O
O
OH
OH
OOH
O
O
OHO
O
OH
OH
OH
OH
O
OH
OH
OH
O
O
O
OH
O
OOH
O
O
OHO
OH
OH
O
O
OH
OH
O
OH
OH
OH
OH
O
O
OH
OH
OOH
O
O
OHO
+174
QA-H2O
OH
OH
OH
OH
O
O
OOH
OH
O
OH
O
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
OH
OH
OH
OOH
OH
O
OHO
polymers
Possible transformations of CGA and the effect on AOX
properties
OH
OH
OH
OOH
OH
O
OHO
Chlorogenic acid
AOX property
Polymerization
OH
OH
OH
OH
O
OH
OH
OH
O
O
O
OH
O
OOH
O
O
OHO
OH
OH
O
O
OH
OH
OH
OH
O
OH
OH
OH
O
O
O
OH
OH
OOH
O
O
OHO
O
OH
OH OH
O
O
OHO
OH
OH
OH
OH
OOH
OH
O
OHO
OH
OH
O
OOH
OH
O
OO
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
x 2
OH
OH
O
OH
CH2
OH
OH
OH
OH
OH
OH
OH
OH
CH3
S
O
OH
OH
Nucl.
Conclusions
• Chlorogenic acids can be used to evaluate green coffee quality
with regards to variety, origin and post-harvest treatment
• Chlorogenic acids play a crucial role in the formation and
degradation of important coffee aroma compounds
• Chlorogenic acids are the main precursors of several bitter
compounds in coffee
• Chlorogenic acids are converted into various compounds upon
thermal treatment whilst maintaining the antioxidant activity
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
…Coffee is the
most pleasurable
hot beverage in
the world
But one thing is sure...
PTC Orbe-Science&Nutrition / AGL / 13.11.2012
Recommended