2009_Book_FoodChemistry

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
Volatile compounds a 326 49 37 188 83
Volatile compounds a
α-Pinene 5.8 1.2 1.4 3.1 0.6
α-Phellandrene b 198.1 13.3 8.1 41.6 14.9
Limonene 10.0 0.7 0.4 2.0 0.7
β-Phellandrene 27.5 2.2 1.1 6.5 1.8
p-Cymene 5.5 1.1 0.4 4.0 0.1
3,9-Epoxy-p-ment-1-ene b 39.8 0.5 Traces 8.9 1.4
Myristicin 4.4 0.6 0.3 4.3 1.5
Neophytadiene 1.0 6.3 2.6 38.2 26.0
a Values in mg per 100 g of dry weight.
b Aroma substances that determine quality.
L-isoleucine (XIX in Formula 22.6) is cyclized to
the amine XX, which is then converted to HD2F
via the Strecker reaction, e. g., with methylglyoxal.
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)
Mustard and horseradish contain glucosinolates
(Table 22.6) which, after cell rupture, are exposed
to the action of a thioglucosidase enzyme
(cf. 17.1.2.6.5), yielding isothiocyanates (mustard
oil). Allyl isothiocyanate is obtained from the glucoside
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 mustard.
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 camphorlike,
flowery, musty, fatty and green odor. In a column
chromatographic preliminary separation of
an extract, the characteristic aroma substances appeared
in the fraction of the oxidized hydrocarbons.
The highest FD factors in dilution analyses
were obtained for geraniol, linalool, geranial, citronellyl
acetate, borneol, 1,8-cineol and neral.
22.1.1.2.6 Mustard, Horseradish
22.1.1.2.8 Basil
The aroma profile of basil is characterized
by green/fresh, flowery, clover- and pepper-