Food Chemistry

824 18 Fruits and Fruit Products

Table 18.16.Derivatives of hydroxycinnamic acid in pomme and stone fruitsa

Compound Apple Pear Sweet Sour Plum Peach Apricot
cherry cherry

5-Caffeoylquinic acid 62–385b 64–280 11–40 50–140 15–142 43–282 37–123
4-Caffeoylquinic acid 2 – ++9––
3-Caffeoylquinic acid – – 73–628 82–536 88–771 33–142 26–132
3-p-Coumaroylquinic acid – – 81–450 40–226 4–40 2 2–9
3-Feruloylquinic acid – – 4 1 13 1 7
p-Coumaroylglucose 4 + ––15––
Feruloylglucose 3 – – – 5 – –
amg/kg of fresh weight,
bvariety “Boskop”: 400–500 mg/kg.

Table 18.17.Derivatives of hydroxycinnamic acid in berriesa

Compound Straw- Rasp- Black- Red Black Goose- Cultured
berry berry berry currant currant berry blueberry

Caffeoylquinic acid – 1 45–53 1 45–52 3 1860–2080
p-Coumaroylquinic acid – 1 2–5 + 14–23 1 2–5
Feruloylquinic acid – + 2–4 2 4 1 8
Caffeoylglucose 1 3–7 3–6 2–5 19–30 5–13 +
p-Coumaroylglucose 14–17 6–14 4–11 1 10–14 7 +
Feruloylglucose 1 4–7 2–6 + 11–15 1–6 +
Caffeic acid-4-O-glucoside – – – 2 2 2 3
p-Coumaric acid-O-glucoside + 5–10 2–5 5–16 4–10 6–8 3–15
Ferulic acid-O-glucoside – + – – 3 2–7 8–10
amg/kg of fresh weight. The hydroxycinnamoylquinic acids are present mostly as the 3-isomers, but in blueber-

ries as the 5-isomer.

esters of caffeic, coumaric, and ferulic acids
withD-quinic and, in addition, withD-glucose
(Tables 18.16 and 18.17). Since quinic acid
has four OH groups, fourbonding possibilities
exist (R^1 ,R^3 –R^5 in Formula 18.11), the 3-
and 5-isomers being preferred. According to
IUPAC nomenclature for cyclitols, the 3-, 4-, and
5-caffeoylquinic acids are identical to neochloro-
genic acid (V), cryptochlorogenic acid (VI), and
chlorogenic acid (VII). Isochlorogenic acid is
a mixture of di-O-caffeoylquinic acids. Apart
from quinic acid and glucose, other alcoholic
components are shikimic, malic and tartaric
acids and meso-inositol. Sinapine, which is
found in mustard seed, is the counter ion of the
glucosinolate sinalbin and is the choline ester
of sinapic acid, which is as bitter as caffeine.
Hydroxycinnamic acid amides are also found in
plants.
Scopoletin (VIII, Formula 18.12) in esterified
form is the only hydroxycoumarin (Table 18.18)

Table 18.18.Hydroxycoumarins in fruit (VIII)a

Compound Substitution pattern

R^1 R^2 R^3

Coumarin H H H

Umbelliferone H OH H

Herniarin H OCH 3 H

Aesculetin OH OH H

Scopoletin OCH 3 OH H

Fraxetin OCH 3 OH OH

aSee Formula 18.12.

which has been found, in small amounts, in

plums and apricots.

(18.12)