Pigments and other colorants - vscht.cz Pigments and... · Pigments and other colorants Colou red...
Transcript of Pigments and other colorants - vscht.cz Pigments and... · Pigments and other colorants Colou red...
Pigments and other colorants
Coloured compounds (colorants, pigments)
colour effect based on the selective absorption of certain wavelengths
resulting colour is determined by the spectrum of reflected wavelengths of light
natural pigments
synthetic pigments identical to natural pigments
synthetic pigments
natural colorants - also derived from natural raw materials by technological processes (caramel) discoloration - undesirable colour change
light – elmg. radiation visible to
the human eye (400-800 nm)
NATURAL COLOURS
formation
primary compounds natural food components natural components of other materials (microorganisms, algae, higher plants) used as additives
secondary compounds enzymatic reactions (non-enzymatic browning reaction) chemical reactions
important groups
tetrapyrrole colours plants, animals
hem colours
chlorophyll colours
betalain colours plants
betacyans
betaxanthins
flavonoid colours plants
anthocyanins
anthoxanthins
phenolic and quinoid colours plants, animals
phenols
quinones
carotenoid colours plants, animals
carotenes
xanthophylls
TETRAPYRROLE PIGMENTS (TETRAPYRROLES)
porphyrin pigments (porphyrins) cyclic
hem pigments (haems)
chlorophyll pigments (chlorophylls)
biline pigments (bilines) linear
phycobilins
1
2
34
56
7
8
9
10
11
12
1314
1516
17
18
19
20
NH N
N NH
A B
CD
A B C D1
2 3
4
5
6
7 8
9
10
11
12 13
14
15
16
17 18
19
N
H
N N N
porphyrins bilines
haem pigments meat, meat products haem (reduced haematin, Fe2+) haemoglobin haematin (Fe3+) myoglobin (P = globin residue,16,8 kDa)
H
(II)
P
H2O
CH2
H3C
N
N
N N
N N
CH3
H3C
CH3
CH2=CH
CH=CH2
HOOCCH2CH2 CH2CH2COOH
Fe
HOOCCH2CH2 CH2CH2COOH
H3C CH3
CH3
H3C
NN
NN
Fe (II)
CH=CH2
CH2=CH
His93
myoglobin (Mb) dark red
oxymyoglobin (MbO2) scarlet
metmyoglobin (MMb) red to brown
Meat Myoglobin mg.kg-1
Haemoglobin mg.kg-1
Proportion of
haemoglobin (%)
Beef 3140-7020 340-520 6-10
Pork 790-2320 360-1200 25-50
O 2
myoglobin oxymyoglobin
N
Fe
N
N
N
(II)
protein
H2O
N
Fe
N
N
N
(II)
protein
O O
OH
metmyoglobin
N
N
Fe
N
N
(III)
protein
formation of MMb autoxidation
P-Fe2+ (Mb) + O2 P-Fe3+ (MMb) + O2- (superoxide anion radical)
2 O2- + 2 H+ H2O2 + O2
3+ 3+ 4+ - P-Fe + H2O2 = P-Fe=O P-Fe-O (oxen, hypervalent Fe)
initiation of lipid peroxidation
reaction of MMb during temperature processing of meat
metmyoglobin globin denaturation (70-80 oC) globin hydrolysis hematin or haem (loss Fe3+ nebo Fe2+) linear tetrapyrroles
stabilization of meat and meat products colour microflora
meat + NO3- NO2-
2 Mb + NO2- 2 MMb + NO + H2O
Mb + NO MbNO + H2O
heating: MbNO Mb(NO)2 + globin
MbNO = nitroxymyoglobin
Mb(NO)2 = nitroxyhaemochrom (nitrosylhaemochrom, nitroxymyochromogen)
use of ascorbic acid: MMb + H2A Mb + A
fuscous up to green colours (sulfomyoglobin, verdochrom, cholemyoglobin)
CHLOROPHYLL PIGMENTS green parts of fruits and vegetables porphyrins chlorophylls complex Mg (II) chlorophylls R = CH3 chlorophyll a yellow-green R = CH=O chlorophyll b blue-green without Mg (II) pheophytin without phytol chlorophyllide without Mg (II) and phytol pheophorbide
N N
N N
Mg (II)
CH2=CH
Mg
R
(II)
CH3
CH3 CH3 CH3 CH3O
NN
NN
H3C CH2CH3
CH3
OCH2
H3C
CH2
CO O
C O
CH3 methyl
fytyl
3
1
reactions of chlorophylls during processing (acids, enzymes)
chlorophylls
strong acid
weak acid
strong acid
strong acid
chlorophyllide
pheophorbide
pheophytin
Chlorophyllase
colour stabilisation
chlorophylls, Cu complex of chlorophylls - Fat-soluble green dye mixture chlorophyllin (Na and K salts of various compounds) - teal, soluble in
water
Cu complex of chlorophyllin – green stable colorants
+
2 H
- 2 H+
+
Mg
- Mg2+
2+
o
feofytinchlorofyl
N N
N N
Mg (II)
H
H
N N
N N
N N
N N
Cu (II) měďnatý komplex
Cu , - 2H2+
Cu , - Mg 2+ 2+
chlorophyll phaeophytin
Chlorophyll Cu2+ complex
BETALAIN PIGMENTS
beetroot prickly pear amaranth Amanita muscaria
Beta vulgaris
betacyanins red, orange
betaxanthins yellow, orange
basic structure
N COOHH
N
H
HOOC
RR1
+
betanin (R = H) vulgaxanthin I (R = NH2) vulgaxanthin II (R = H)
H
CH2OR
+
N COOH
N
H
HO COOH
HOOC
H
HO
OH
OH
OO
H
H
OR
N
N
H -+
COO
COOHHOOC
dominating betacyamin in beetroot (1-2 g/kg) use powder with 6-7% dyes beet (after fermentation, drying)
dyeing of dairy and meat products, soft drinks, sweets
FLAVONOID PIGMENTS
fruits, vegetables, flowers anthocyanins red, violet, blue anthoxanthins yellow, orange
(anthos = flower, kyaneos = blue, xanthos = yellow) cca 5000 compounds
basic structure
2H-chromene flavan
OO
substituted by phenyl
oxidation of 3C chain (ring B)
OH groups in rings A, B, C
aglycones, glycosides
colourless colourless- light yellow yellow light pale yellow red-blue
+
O
anthokyanidiny
flavonoly
O
O
flavony
O
O
OH
flavanonoly
O
O
flavanony
O
OH
OH
leukoanthokyanidiny
O
OH
katechiny
O
O
OH
Favan-3-ols catechins
Favan-3,4-diols leucoanthocyanidins
flavanonols flavavonols
flavanones flavones
anthocyanidines
Anthocyanins aglycones=anthocyanidins glycosides=anthocyanins
basic structure
+
O
OH
OH
OH
HO
R
R
1
2
35
7
pelargonidin Pg R1 = H R2 = H violet-red
cyanidin Cy R1 = H R2 = OH violet
delfinidin Dp R1 = OH R2 = OH blue-violet
peonidin Pn R1 = H R2 = OCH3 violet
petunidin Pt R1 = OH R2 = OCH3 dark red
malvidin Mv R1 = OCH3 R2 = OCH3 blue-violet
saccharides: Glc, Gal, Xyl, Ara, Rha,
always at C-3, often at C-3 and C-5, seldom at C-7
acids: p-cumaric, caffeic, ferulic
anthocyanins fruits and vegetables
sophorose = -D-Glcp-(12)-D-Glcp
rutinose = -L-Rhap-(16)-D-Glcp
fruit anthocyanins sacharide, acid Blueberry Dp 3-rutinoside, 5-glucoside, 3-glucoside
(myrtillin) Grapes Cy, Pn, Dp, Pt,
Mv 3-p-kumaroyl, 3-kaffeoyl-3-glucosids
Strawberries Pg, Cy 3-glucoside Raspberries Cy, Pg 3-sophoroside, 3-rutinoside, 3-glucoside Blackberry Cy, Mv 3-glucoside, 3-rutinoside, free/acyls Black currant Cy, Dp 3-glucoside, 3,5-diglucoside, 3-rutinoside Cherries Cy, Pn 3-glucoside, 3-rutinoside vegetable anthocyanins sacharide, acid Onion Cy 3-glucoside, 3-galactoside (idaein) Eggplant Dp 3-glukoside, 3-rutinoside, 3,5-diglucoside Cabbage Cy malonyl (p-coumaroyl, di-p-coumaroyl,
feruloyl)-3-sophoroside-5-glucoside
colour changes due to different factors
pH
co-pigmentation, eventual transformation into other pigments
SO2
H2O2
pH
,2
1R
R
R1
R2
R1
R2
R1
R2
R1
R2
R1
R2
glykosyl
glykosylglykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
glykosyl
R1
R2
+
- H+
flavyliový kation (červený) karbinolová pseudobáze (bezb.)
H+
H+
neutrální chinoidní báze (tmavě červená)
chalkon (žlutá)H
+ H+
anion chinoidní báze (modrá)
--
- -
H2O
OH
O
HO O
O
OHOH
O
HO O
O
O
O
HO O
O
OH
O
O O
OOH
O
HO
O
OHO
O
O
-O O
O
O-
O
O O
O
H2O-
pH < 1 pH 4,0-4,5
pH 7,5-8
pH > 8
pH 4,5-7,5
glycosyl
glycosyl glycosyl
glycosyl
glycosyl
glycosyl glycosyl
glycosyl
glycosyl
glycosyl
glycosyl
glycosyl glycosyl
glycosyl
flavylium cation (red) carbinol pseudo base (colourless)
chalcone (yellow)
neutral quinoid bases (dark red)
quinoid base anions (blue)
copigmentation
interaction with procyanidinins
(catechins = copigments) → coloured complexes
transformation into other pigments
coloured complexes → dimers (oligomers)
OR
OR
+
8
4
HO
OH
O
R
R
OH
OH
R
RHO
OH
O
anthokyanidin
katechincatechin
anthocyanin
non-soluble condensation products, polymeric compounds flobafens
SO2 colourless sulfonic acids
H2O2 colourless products
HO2SO
OSO2H
OH
O
HO O
R
R
O
1
2
glykosyl
glykosyl
OH
O
O
R
R
O
1
2
glykosyl
glykosyl
O
HO OO
CO
O
R
R
OH
glykosyl
glykosyl
1
2
glycosyl
glycosyl glycosyl
glycosyl
glycosyl
glycosyl
Anthoxanthins flavanones pigments of low importance
bitter compounds of grapefruits
naringin = naringenin + neohesperidose
neohesperidin = hesperetin + neohesperidose
flavanonols pigments of low importance flavones important anthoxanthins
flavonols important anthoxanthins antioxidant activity, rutin = kvercetin + rutinose, bioflavonoids Isoflavones pigments of low importance (e.g. in soybeans) estrogenic activity chalcones and aurones important pigments of flowers
(karthamin) dihydrochalcones pigments of low importance neohesperidindihydrochalcone (synthetic sweet compound)
QUINOID PIGMENTS lichens, mushrooms, higher plants phenols quinones phenols curcuminoides (diarylheptanoides)
curcumin (curcuma, curry)- yellow to orange
CH3O
O O
OCH3
OHHO
Extraction from rootstock Turmeric
(Curcuma longa)
quinones benzoquinones naphtoquinones anthraquinones
benzo-1,4-quinone naphtho-1,4-quinone anthra-9,10-quinone
O
O
O
O
O
O
Benzoquinones arbutin (cranberry leaves, antiseptic activity)
O
CH2
OH
OH
HO
HO
OH
O
Naftoquinones juglone (leaves of walnut, 4-β-D-glucosid 1,4,5-trihydroxynaphtalene) (relative gossypol in cotton seeds, related coenzymes Q, vitamins K)
O
OOH
Anthraquinones related emodins, bianthrons carminic acid (cochineal, dried bodies of female beatles Coccus cacti)
hypericine (St. John's wort)
O OH
CH3
HO
CH3
OHO
HO
HO
HO
HO
OH
OH
CH2OH
O
OH
COOH
OH
CH3
HO
OH
O
O
E120 – meat and diary products, candy
carotenoid pigments yellow, orange, red up to violet
pigments of plants and microorganisms (in mammals)
carotenoids (tetraterpenes, 40 C atoms, trans-isomers)
hydrocarbons carotenes
O-derivatives xanthophylls
neocarotenoids (cis-isomers)
degradated carotenoids (30, 20, 15, 13, 10 C atoms)
Carotenes acyclic and alicyclic hydrocarbons lycopene: tomato, rose-hip, β-carotene: carrot, apricot, mango
H3C
CH3 CH3 CH3 CH3
CH3 CH3 CH3
CH3
CH3lykopen
CH3
OH
H3C
H3C
CH3CH3
CH3CH3
CH3
CH3H3C
-karoten
lycopene
β-carotene
Xanthophylls alcohols, ketones, epoxides free, bound (glycosides, fatty acids esters, carotenoproteins)
CH3
OH
H3C
H3C
CH3CH3
CH3CH3
CH3
CH3
HO
H3C
CH3
OH
H3C
H3C
CH3CH3
CH3CH3
CH3
CH3
HO
H3C
zeaxanthin
lutein (-xanthofyl, kukurbitaxanthin) OH
H3C CH3
CH3O
CH3CH3
CH3CH3
CH3
CH3
HO
H3C
kapsanthin
O
OH
CH3H3C
H3C
O
HO
CH3H3C
CH3
CH3CH3
CH3CH3
astaxanthin
zeaxanthin, lutein: generally wide-spread kapsanthin: red bell pepper astaxanthin: fish, shellfish (α-crustacyanin)
Contenten (mg/kg)
Carotenoids Apricot Orange Carrots Spinach Tomato
Carotnes Lycopene 0.1 16-750 Neurosporene 3.0 -Carotene 0.4 0.5 8.4 Phytofluene 0.3 1.3 5.1 Phytoene 0.6 0.4 6.0 -Carotene 64 0.1-0.4 46-103 33-89 2.8-5.8 -Carotene 0.1-0.2 22-49 trace -Carotene 0.2 6.3-27 0.4-1.6 Xanthophylls 5,6-epoxylycopene 5.3 -Cryptoxanthin 0.1-7.1 Zeaxanthin 0.5 Lutein 0.3 1.1-5.6 42-81 0.4-1.3 Antheraxanthin 0.6 Violaxanthin 0.7 74 Neoxanthin 24 Mutatoxanthin 0.6 5.0 Luteoxanthin 1.7 Auroxanthin 1.2
degradated carotenoids crocin (18 C)
saffron (Crocus sativus), spice
HOOCCOOH
CH3 CH3
CH3CH3krocetin
krocinOH
H
O
O
H
OH
O
OH
OH
CH2
O
O
OH
CH2
O
CH2
O
OH
O OH
HOO
CH3CH3
CH3CH3
CC
O
O
O OH
OH
HOCH2OH
genciobiosa
•1 kilogram of dried saffron is roughly 150 000 and 200 000 flowers →high price • odor is sharp and pungent, tastes warm, earthy, musky
crocetin
crocin
gentiobiose
annato (20 C)
bixin (Bixa orellana)
extract 0,2-0,5% = mixture cis/trans-isomers,
cheese and margarine colouring
9
,HOOCCH3
CH3 CH3
CH3
COOH
HOOC
CH3 CH3
CH3CH3
COOH
Annatto is commonly
used in Latin American
and Caribbean cuisines
as both a coloring and
flavoring agent.
reactions
hydrolysis of esters, glycosides
dehydration of alcohols to hydrocarbons
cis/trans isomeration
(neocarotenoids, low colour intensity)
autoxidation
(low colour intensity, even decolourisation)
antioxidants
consequences • flour bleaching • colour changes of orange juices • food flavour • beneficial food components
ENZYMATIC BROWNING REACTIONS substrates
phenols, diphenols (polyphenols), esters (depsides), glycosides
HO R HO
HO
R
Food Substrate Potatoes Tyr, chlorogenic acid, catechins Apple flesh chlorogenic acid Apple skin flavonoids (catechins) Pears chlorogenic acid (caffeic + quinic) Olives 3,4-dihydroxyphenylethanol and its derivatives Bananasy 3,4-dihydroxyphenylethylamie Dates dactyliferic (caffeic + shikimic) acid Beans DOPA Mushrooms Tyr, terfenylchinons Tea flavonoids (catechins) Coffee chlorogenic and caffeic acid Cocoa flavonoids (catechins)
OH
HO
daktyliferová kyselinachlorogenová kyselina
3
COOH
OH
OH
O
O
OH
OH
3
COOH
OH
OH
OH
O
O
OH
OH
O
O
O H
HOR
R
terfenylchinony
HO
HO
NH2
3,4-dihydroxyfenylethylamin
chlorogenic acid dactyliferic acid
3,4-dihydroxyphenylethylamie terphenylquinones
enzymes
Polyphenoloxidases
catecholoxidase
1/2 O2 1/2 O2
OH
R
OH
R
OH
O
O
R
H2O-
fenol o-difenol o-chinon
kresolasa katecholasa
phenol o-diphenol o-quinone
cresolase catecholase
laccase
catechin oxidation yellow quinone
chlorogenic acid oxidation yellow-orange quinone
DOPA oxidation orange quinone
OH
HO
R
H2O-
R
O
O
OH
R
OH
O
O
R
H2O-
o-difenol o-chinon
p-difenol p-chinon
lakkasa
lakkasa
1/2 O2
1/2 O2
laccase
laccase
o-diphenol
p-diphenol
o-quinone
p-quinone
Non-enzymatic oxidation
inhibition of browning (book 3, tab. 9.16)
inhibition of enzymes (oxygen elimination , decrease of pH)
chelatation of metals (Cu2+)
use of reducing compounds (ascorbic acid, SO2)
desirable reactions
tee fermentation
cocoa fermentation
olive fermentation
oxidace
hnědé
pigmenty
OH
R
OH
O
O
R
+
OH
OH
R
R
HO
OH
R
HO
OH
O
O
R1/2 O2
- H2O
reakce s R-SH, R-NH2
oxidace
polymerace
komplexy s kovy
oxidation
reaciton with R-SH, R-NH2
oxidation
polymerization
metal complexes
brown
pigments
black tea
precursors in green tea
epigallocatechingallates
epicatechins
epicatechingallates
epigallocatechins
main types of black tea pigments
theaflavins (oxidised flavonoid dimers),
orange-red (seven-carbon tropolone cycles)
thearubigines (polymers, 700-400 000 Da),
red-yellow up to orange-brown
1
OHO
OH
H
H
OH
OHOR
OR
HO
OH
O
H
HO
OH