Food Chemistry

22.1 Spices 977

Table 22.5.Changes in aroma substances in the drying of dill (leaves)

Dried (air) Freeze dried

Fresh 25 ◦C/4h 50 ◦C/4h − 25 ◦C/59 h − 25 ◦C/65 h

Water (w/w%) 90 11 12 16 2
Volatilecompoundsa 326 49 37 188 83

Volatilecompoundsa
α-Pinene 5. 81. 21. 43. 10. 6
α-Phellandreneb 198. 113. 38. 141. 614. 9
Limonene 10. 00. 70. 42. 00. 7
β-Phellandrene 27. 52. 21. 16. 51. 8
p-Cymene 5. 51. 10. 44. 00. 1
3,9-Epoxy-p-ment-1-eneb 39. 80. 5 Traces 8. 91. 4
Myristicin 4. 40. 60. 34. 31. 5
Neophytadiene 1. 06. 32. 638. 226. 0

aValues in mg per 100 g of dry weight.

bAroma substances that determine quality.

L-isoleucine (XIX in Formula 22.6) is cyclized to
the amine XX, which is then converted to HD2F
via theStreckerreaction, e. g., with methylgly-
oxal.

22.1.1.2.5 Saffron

In aroma extract dilution analyses (cf. 5.2.2),
a compound with a saffron and hay-like odor,
which could be 2-hydroxy-4,4,6-tri-methyl-2,5-
cyclohexadien-l-one, gave the highest FD factor.

This was followed by the terpene aldehyde
safranal and an unknown compound, both of
which have a saffron odor. Safranal (XXIV)
is probably obtained from the bitter substance
picrocrocin (XXII) by hydrolysis and elimination
of water (Formula 22.6).

(22.6)

22.1.1.2.6 Mustard, Horseradish

Mustard and horseradish contain glucosinolates
(Table 22.6) which, after cell rupture, are ex-

posed to the action of athioglucosidaseenzyme

(cf. 17.1.2.6.5), yielding isothiocyanates (mustard

oil). Allyl isothiocyanate is obtained from the glu-

coside sinigrin, a compound responsible for the

pungent burning odor and taste of both spices.

p-Hydroxybenzyl isothiocyanate obtained from

sinalbin is only slightly volatile and contributes

significantly to the sharp pungent taste of mus-

tard.

The aroma of horseradish is also influenced

by methyl, ethyl, isopropyl and 4-pentenyl

iso-thiocyanates which, however, are present

only in very small amounts in comparison to allyl

isothiocyanate.

22.1.1.2.7 Ginger

The fresh ginger root has a citrus and camphor-

like, flowery, musty, fatty and green odor. In a col-

umn chromatographic preliminary separation of

an extract, the characteristic aroma substances ap-

peared in the fraction of the oxidized hydrocar-

bons. The highest FD factors in dilution analyses

were obtained for geraniol, linalool, geranial, cit-

ronellyl acetate, borneol, 1,8-cineol and neral.

22.1.1.2.8 Basil

The aroma profile of basil is characterized

by green/fresh, flowery, clover- and pepper-