2009_Book_FoodChemistry

646 14 Edible Fats and Oils
Table 14.6. Olive oils: concentrations of the minor constituents
Type Alcohols a Waxes a,b Sitosterol a Erythrodiol a Erythrodiol +
free esterified Uvaol (%) c
Extra vierge oil 67 40 914 219 13 1
“Lampante” oil, raw 84 292 945 877 10 0.6
“Lampante” oil, refined 44 180 692 544 8 0.8
Extraction oil, raw 725 3294 1234 2702 283 13.5
Extraction oil, refined 75 3277 659 2624 116 5.6
a Values in mg/kg.
b Sum of the wax esters C 40 –C 46 .
c Percentage of the sum of sterols and triterpene dialcohols.
(cf. Table 5.34), which has the highest aroma
value of all the volatile compounds in oil II
(Table 14.7).
The fatty acid composition of tea seed oil is very
similar to that of olive oil. However, these two oils
can be differentiated by using the Fitelson Test
(cf. Table 14.21).
(14.1)
The aroma of natural oils is of special interest.
The most important aroma substances of two
extra vierge olive oils with different aromas are
shown in Table 14.7. In oil I, green, fruity, and
fatty notes are predominant while in oil II, the
compounds with a green odor are concealed by
an aroma substance with a “blackcurrant” odor,
possibly due to a special variety of the olives.
The compound involved is the extremely intensive
odorant 4-methoxy-2-methyl-2-butanethiol
14.3.2.1.2 Palm Oil
This oil is obtained from oil palm, the utilization
of which is constantly increasing (cf. Table
14.1). Palm plantations are found primarily in
western Malaysia and Indonesia (cf. Table 14.0).
The fruits provide two different oils, the first from
the pulp and the second from the seeds.
Oil Production. The fruit cluster, which contains
about 3000–6000 fruits, is first steam-treated to
inactivate the high lipase activity and to separate
the pulp from the seed. The oil is recovered
by pressing the disintegrated pulp. The crude
Table 14.7. Important aroma substances of two extra vierge olive oils a
Oil I
Oil II
Aroma substance Aroma quality C A x C A x
Isobutyric acid ethyl ester Fruity 4.9 7 14 19
2-Methylbutyric acid ethyl ester Fruity 3.9 5 14 19
Cyclohexanoic acid ethyl ester Fruity 1.6 4.2 4.3 11
(Z)-3-Hexenal Green 33 12 53 19
(Z)-2-Nonenal Green, fatty 9 15 10 17
Acetic acid Like vinegar 10,490 10 6680 6
4-Methoxy-2-methyl-2-butanethiol Like blackcurrants n.d. 1.8 40
a Oil I is from Italy, oil II from Spain; concentration C is in µg/kg and the aroma value A x is calculated on the
basis of the odor thresholds (retronasal) in an oil; n.d.: not detectable (C < 0.05 µg/kg).