Food Chemistry

18.1 Fruits 819

Table 18.11.Carotenoids occurring in fruit (Roman nu-
merals refer to their structures shown in 3.8.4)

Number Carotenoid

1 Phytoene (I)

2 Phytofluene (II)

3 ζ-Carotene (III)

4 Lycopene (IV)

5 α-Carotene (VI)

6 β-Carotene (VII)

7 β-Zeacarotene (Va)

8 Lycoxanthin (16-hydroxylycopene)

9 α-Cryptoxanthin (3-hydroxy-α-carotene)

10 β-Cryptoxanthin (3-hydroxy-β-carotene)

11 β-Carotene-5,6-epoxide

12 Mutatochrome (β-carotene-5,8-epoxide)

13 Lutein (IX)

14 Zeaxanthin (VIII)

15 Cryptoflavin (α-cryptoxanthin-5,8-epoxide)

16 β-Carotene-5,6,5′,6′-diepoxide

17 Antheraxanthin (zeaxanthin-5,6-epoxide)

18 Lutein-5,6-epoxide

19 Mutatoxanthin (XVI)

20 Lutein-5,8-epoxide

21 Cryptoxanthin-5,8,5′,8′-diepoxide

22 Violaxanthin (XIII)

23 Luteoxanthin (XIV)

24 Auroxanthin(zeaxanthin-5,8,5′,8′-diepoxide)

25 Neoxanthin (XX)

26 Capsanthin (X)

Table 18.12.Carotenoid patterns of various fruits

Fruit Carotenoid

Contenta Compoundsb

Pineapple 6, 13
Orange 24 1, 2, 3, 4, 6, 10, 11, 12, 15, 17,
20, 21, 22, 23, 24
Banana 6, 13
Pear 0 .3–1.3 2, 3, 6, 7, 8, 11, 12, 13, 14, 16,
18, 20, 24, 25
Fig 8. 5 1, 2, 5, 6, 13, 14, 22, 23, 25
Guava 5, 6
Peach 27 1, 2, 3, 5, 6, 9, 10, 13, 14, 17,
18, 19, 22, 23, 24
Plum/ 1, 2, 3, 5, 6, 9, 10, 12, 14, 15,
prune 17, 18, 19, 20, 22, 23, 25
Grapes 1. 8 1, 2, 4, 5, 13, 14, 22, 23
Cantaloupe 20–30 1, 2, 3, 5, 6, 13, 14, 22, 23
amg/kg fresh weight.
bThe numerals refer to Arabic numerals in Table 18.11.

• Fruits with relatively high contents of ly-
  copene, phytoene, phytofluene, ζ-carotene
  and neurosporene, e. g., peaches.


• Fruits with relatively high contents ofβ-caro-
  tene, cryptoxanthin and zeaxanthin. This class
  includes oranges, pears, peaches and sweet
  melons.


• Fruits with high amounts of epoxides, e. g., or-
  anges and pears.


• Fruits which contain unusual carotenoids,
  e. g., oranges.

The compositional pattern of carotenoids which

can be readily analyzed by HPLC is important for

analytical characterization of fruit products.

18.1.2.3.3 Triterpenoids

This fraction contains bitter compounds of

special interest, limonoids and cucurbitacins.

Limonoids are found in the flesh and seeds ofRu-

taceaefruits. For example, limonin (II) is present

in seeds, juice, and fruit flesh of oranges and

grapefruit. The limonin content decreases with

fruit ripening in oranges but remains constant in

grapefruit. Development of a bitter taste in heated

orange juice is a processing problem. Limonin

monolactone (I), a nonbitter compound which

is stable in the neutral pH range, is present in

orange albedo and endocarp. During production

of orange juice it is transferred to the juice in

which, due to the lower pH, it is transformed

(18.5)