21.3 Cocoa and Chocolate 96377 mg/g epicatechin equivalents (ECE), cocoa
powder contains very high concentrations com-
pared to, e. g., green (83 mg/g GAE, 24 mg/g
ECE) and black tea (62 mg/g GAE, 17 mg/G
ECE).
Three groups of phenols are present in cocoa: cat-
echins (about 37%), anthocyanins (about 4%) and
leucoanthocyanins (about 58%).
The main catechin is (−)-epicatechin, besides
(+)-catechin, (+)-gallocatechin and (−)-epi-
gal-locatechin. The anthocyanin fraction con-
sists mostly of cyanidin-3-arabinoside and
cyanidin-3-galactoside.
(21.9)Pro- or leucoanthocyanins are compounds which,
when heated in acidic media, yield anthocyanins
and catechins or epicatechins, respectively. The
form present in the greatest amount is flavan-3-4-
diol (I in Formula 21.9) which, through 4→8 (II)
or 4→6 (III) linkages, condenses to form dimers,
trimers or higher oligomers (cf. 18.1.2.5.2, For-
mula 18.20).
Leucoanthocyanins occur in fruits of various
plants in addition to cacao; e. g., apples, pears
and cola (kola) nuts.21.3.2.3.6 Organic AcidsOf the organic acids (1.2–1.6%), citric, acetic,
succinic and malic acid contribute to the taste of
cocoa (Table 21.23). They are formed during fer-
mentation. The amount of acetic acid released by
the pulp and partly retained by the bean cotyle-
dons depends on the duration of fermentation and
on the drying method used. Eight brands of co-
coa were found to contain 1.22–1.64% total acids,
0 .79–1.25% volatile acids and 0.19–0.71% acetic
acid.Table 21.23.Taste substances of roasted cocoa nibs
Compound Concentration
(mmol/kg)Bitter Group
cis-cyclo (L-Pro-L-Val) 8. 9
Theobromine 63. 6
cis-cyclo (L-Val-L-Leu) 0. 82
cis-cyclo (L-Ala-L-Ile) 0. 64
cis-cyclo (L-Ile-L-Pro) 0. 54
Astringent Group
N-[3′,4′-Dihydroxy-(E)-cinnamoyl]-
3-hydroxy-L-tyrosine 0. 9
(−)-Epicatechin 8. 6
Quercetin-3-0-β-D-glucopyranoside 0. 10
Quercetin-3-0-β-D-galactopyranoside 0. 034
γ-Aminobutyric acid 5. 0
Sour Group
Citric acid 31
Acetic acid 17
Succinic acid 1. 7
Malic acid 3. 6