OXIDATIVE STABILITY OF PURIFIED CANOLA OIL TRIACYLGLYCEROLS WITH ALTERED FATTY-ACID COMPOSITIONS AS AFFECTED BY TRIACYLGLYCEROL COMPOSITIONAND STRUCTURE
We. Neff et al., OXIDATIVE STABILITY OF PURIFIED CANOLA OIL TRIACYLGLYCEROLS WITH ALTERED FATTY-ACID COMPOSITIONS AS AFFECTED BY TRIACYLGLYCEROL COMPOSITIONAND STRUCTURE, Journal of the American Oil Chemists' Society, 71(10), 1994, pp. 1101-1109
Canola oil triacylglycerols from genetically modified canola lines (In
terMountain Canola Co., Cinnaminson, NJ) have been evaluated for their
photooxidative and autoxidative stabilities, as influenced by their f
atty acid compositions and their triacylglycerol compositions and stru
ctures. Purified canola oil triacylglycerols were oxidized in duplicat
e in fluorescent light at 25 degrees C and in the dark at 60 degrees C
under oxygen, and their oxidative deterioration with time was monitor
ed by determining colorimetric peroxide values. Also monitored with ti
me, oxidation products were determined by reversed-phase high-performa
nce liquid chromatography with ultraviolet absorbance detection. Total
volatiles, generated by thermal decomposition of the oxidized triacyl
glycerols, were quantitated by static-headspace gas chromatography. Th
ese experimental parameters were statistically correlated with predict
ed oxidizability, fatty acid composition, position of fatty acids on g
lycerol carbons and triacylglycerol composition. Oxidative deteriorati
on of canola triacylglycerols correlated negative ly with oleic acid c
omposition, with oleic acid content at carbon 2 and with trioleoylglyc
erol content of the oil. Deterioration was positively correlated with
the amount of linolenic acid on nonspecific locations on glycerol carb
ons 1,2 and 3, the amount of linoleic acid on glycerol carbon 2 and wi
th sn-oleoyllinoleoyllinolenoyl glycerol content. Differences in chara
cter or quantity of volatile product and triacylglycerol hydroperoxide
s mere low, whether generated during autoxidation or photooxidation of
the canola triacylglycerols.