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18.1 Fruits 823

Table 18.15. Polyphenol content of foods

Compound a Food Content b

Fig. 18.4. Chemical structures of flavonoids

Flavanols (Faol), Anthocyanidines (Acn), Flavanones

(Faon), Flavones (Fon), Flavonols (Fool), Isoflavones

(Ifon, cf. 16.2.9). R: H, OH or OCH 3

a nutritional and physiological viewpoint. Up

to now, however, unambiguous evidence of

a health-building effect is lacking (literature

till 2006). The phenolic compounds contribute

to the color and taste of many types of fruit. In

processing, they can cause discoloration by the

formation of metal complexes and turbidity by

complexation of proteins. Table 18.15 shows the

polyphenol content of foods, which is strongly

dependent on the variety, climate and degree of

ripeness, among other factors. For instance, their

content in apples varies from 1.3g/kg (Golden

Delicious) to6g/kg (Jeanne Renard) and can

even rise to 10 g/kg in this variety.

18.1.2.5.1 Hydroxycinammic Acids,

Hydroxycoumarins

and Hydroxybenzoic Acids

p-Coumaric (I), ferulic (II), caffeic (III) and

sinapic (IV) acids are widespread in fruits and

vegetables.

These hydroxycinnamic acids are present

mainly as derivatives. The most common are

Hydroxybenzoic Blackberries 80–270

acids (Hba) Raspberries 60–100

Black currants 40–130

Strawberries 20–90

Hydroxycinammic Bilberries 2000–2200

acids (Hca) Kiwi 600–1000

Cherry 180–1150

Plum 140–1140

Apple 50–600

Pear 15–600

Aubergine 600–660

Artichoke 450

Chicory 200–500

Potato 100–190

Flavanols c Apricot 100–250

(monomer) (Faol) Cherry 50–250

Grape 30–175

Peach 50–140

Blackberry 130

Apple 20–120

Anthocyans Blackberry 1000–4000

(Acn-glycoside) Black currant 1300–4000

Bilberry 250–5000

Red grape 300–7500

Cherry 350–4500

Rhubarb 2000

Strawberry 150–750

Plum 20–250

Red cabbage 250

Flavanones c Orange (juice) 215–685

(Faon) Grapefruit (juice) 100–650

Lemon (juice) 50–300

Flavones c Parsley 240–1850

(Fon) Celery 20–140

Flavonols c Bilberry 30–160

(Fool) Black currant 30–70

Apricot 25–50

Apple 20–40

Red grape 15–40

Kale 300–600

Leek 30–225

Broccoli 40–100

Bean, green 10–50

Tomato 2–15

a The numbers and abbreviations refer to the formulas

in Fig. 18.5 and 18.6.

b Values in mg/kg fresh weight or mg/l juice.

c Concentration of the aglycone.

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