2009_Book_FoodChemistry

226 3 Lipids
Fig. 3.41. Fungal degradation of triacylglycerols to methyl ketones (according to Kinsella and Hwang, 1976)
Table 3.47. Sensory properties of methyl ketones
Compound Odor Odor threshold
description (ppb; in water)
2-Pentanone Fruity,
like bananas 2300
2-Hexanone 930
2-Heptanone Fragrant,
herbaceous 650
2-Octanone Flowery,
refreshing 190
2-Nonanone Flowery, fatty 190
Table 3.48. Content of unsaponifiables in various fats
and oils
Fat/oil Unsaponi- Fat/oil Unsaponifiable
fiable
(weight-%)
(weight-%)
Soya 0.6–1.2 Shea 3.6–10.0
Sunflower 0.3–1.2 Lard 0.1–0.2
Cocoa 0.2–0.3 Shark 15–17
Peanut 0.2–4.4 (refined)
Olive 0.4–1.1 Herring 0.7–1.0
Palm 0.3–0.9 (refined)
Rapeseed 0.7–1.1
a soap solution (alkali salts of fatty acids) by
extraction with an organic solvent.
The unsaponifiable matter contains hydrocarbons,
steroids, tocopherols and carotenoids. In
addition, contaminants or fat or oil additives,
such as mineral oil, plasticizers or pesticide
residues, can be found.
Each class of compounds in the unsaponifiable
matter is represented by a number of components,