Food Chemistry

242 3 Lipids

Table 3.59.Aroma compounds formed in oxidative degradation of carotenoids

Precursora Aroma compound Odor threshold Occurrence
(μ/1, water)

Lycopene (I) 50 Tomato
6-Methyl-5-hepten-2-one

800 Tomato

Pseudo ionone

Dehydrolycopene 380 Tomato
6-Methyl-3,5-heptadien-2-one

α-Carotene (VI) R(+): 0.5–5
S(−): 20–40

Raspberry, black tea

carrots, vanilla

α-Ionone

β-Carotene (VII) 5Tomato

β-Cyclocitral

0. 007 Tomato, raspberry,

blackberry, passion fruit,

black tea

β-Ionone

Neoxanthin (XX) 0. 002 Tomato, coffee,
black tea, wine,
beer, honey, apple

β-Damascenone

2 Wine, peach,

strawberry

1,2-Dihydro-1,1,6-trimethylnaphthalene

aRoman numerals refer to the chemical structures presented in 3.8.4.1.

belong to the class of C 13 -norisoprenoides. Other
than β-ionone, α-ionone is a chiralic aroma
compound whose R-enantiomer is present almost
in optical purity in the food items listed in Ta-
ble 3.59.α-andβ-Damascone (Formula 3.140),
present in black tea are probably derived from
α-andβ-carotene. Chiro-specific analysis
(cf. 5.2.4) indicated thatα-damascone occurs as
racemate.

(3.140)

The odor thresholds of the R- and S-form (about

1μg/kg, water) differ rarely.