关键词: 自动氧化, 胆固醇, 胆固醇氧化物, 不饱和度, 鱼油, 氢化, 高度不饱和脂肪酸, 三酰甘油酯

Abstract: In order to evaluate the effects of the degree of unsaturation of triacylglycerols on cholesterol oxidation, the respectivemixtures of purified sardine oil triaclglycerols (iodine value,IV=182.6)and cholesterol,of partially hydrogenated sardine oiltriaclglycerols (IV=174.5) and cholesterol, and of fully hydrogenated sardine oil triaclglycerols (IV=92.0) and cholesterol wereincubated at 25℃ in the dark.The oxidative stability of the samples decreased with increasing degree of unsaturation of thetriaclglycerols in the sample mixtures.The induction period for peroxide values (POV) of the sardine oil triaclglycerols andcholesterol was shorter than that of the partially hydrogenated sardine oil triaclglycerols and cholesterol.Certanin polyunsatu-rated fatty acids (PUFAs) in the constituents of sardine oil triaclglycerols started to decrease after a shorter induction periodcompared with that of the partially hydrogenated triaclglycerols.The prominent cholesterol oxides accumulated in the sampleswere 7-β-hydroxycholsterol,7-ketocholsterol, β-epoxide and cholesterol triol. The tendency for accumulation of cholesteroloxides in the time course coincided with the changes in POV as well as the decrease in PUFAs.Cholesterol was oxidized in thetime course coincided with the changes in POV as well as the decrease in PUFAs. Cholesterol was oxidized in conjunction withautoxidation of coexisting fish oil triaclglycerols. Although lowering the degree of unsaturation of fish oil triaclglycerols waseffective in prolonging the induction period of cholesterol oxidation,the rate of cholesterol oxidation in the cholesterol oxides’formation after the induction period was not affected by the difference in the proportion of highly unsaturated fatty acids in thenatural and partially hydrogenated triaclglycerols of fish oils.

Key words: autoxidation, cholesterol, cholesterol oxides degree of unsaturation, fish oil, hydrogenation, polyunsatu-rated fatty acid, triaclglycerol