Food Chemistry

236 3 Lipids

name “carotene”, denoting the structure of both
C 9 - end groups (cf. Formulas III, IV, VI or X:
cf. Formulas 3.120, 3.121, 3.122 and 3.128,
respectively). Designations such as α-, β-or
γ-carotene are common names.
Carotenoids are divided into two main classes:
carotenes and xanthophylls. In contrast to
carotenes, which are pure polyene hydrocarbons,
xanthophylls contain oxygen in the form of hy-
droxy, epoxy or oxo groups. Some carotenoids of
importance to food are presented in the following
sections.

3.8.4.1.1 Carotenes..............................................

Acyclic or aliphatic carotenes

Carotenes I, II and III (cf. Formulas 3.119–

3.122) are intermediary or precursor compounds

which, in biosynthesis after repeated dehydro-

genizations, provide lycopene (IV; see a textbook

of biochemistry). Lycopene is the red color of the

tomato (and also of wild rose hips). In yellow

tomato cultivars, lycopene precursors are present

together withβ-carotene (Table 3.56).

Phytoene (I) (3.119)

Phytofluene (II) (3.120)

ξ-Carotene (7, 8 , 7 ′, 8 ′-tetrahydro-ψ,ψ-carotene) (III) (3.121)

Lycopene (ψ,ψ-carotene) (IV) (3.122)

Table 3.56.Carotenes (ppm) in some tomato cultivars

Cultivar Phytoene Phytoflueneβ-Carotene ξ-Carotene γ-Carotene Lycopene
(I) (II) (VII) (III) (V) (IV)

Campbell 24. 42. 11 .40 1. 143. 8
Ace Yellow 10. 00. 2 trace 0 0 0
High Beta 32. 51. 735 .60 0 0
Jubilee 68. 69. 1012. 14. 35. 1