为了阐明组成三酰甘油的脂肪酸是否饱和对胆固醇氧化的影响,使用气相色谱-质谱联用技术研究了胆固醇在三硬脂酸甘油酯(GTS)和三油酸甘油酯(GTO)中的氧化情况,并同步跟踪过氧化值的变化。结果表明:胆固醇在GTS和GTO中的主要氧化产物为7α-羟基胆固醇、7β-羟基胆固醇、5,6β-环氧基胆固醇、5,6α-环氧基胆固醇、7-酮基胆固醇。在160℃加热条件下,胆固醇氧化产物随时间先增加后减少,未氧化胆固醇逐渐减少,在GTO中过氧化值在加热1 h出现最大值(500.46 meq/kg),在GTS中过氧化值在加热3 h出现最大值(401.30 meq/kg),随后逐渐降低。在110℃加热条件下,胆固醇在GTS中不会氧化,过氧化值亦较低,加热96小时出现最大值(278.43 meq/kg),胆固醇在GTO中几乎完全氧化,过氧化值迅速增加,最大值出现在加热12 h(1486.88meq/kg),随后逐渐减少。总的来说,160℃和110℃加热条件下,胆固醇在GTS中比在GTO中稳定,过氧化值的产生亦会延迟且生成量较小,因此,饱和脂肪酸三酰甘油更有助于保持胆固醇在高温下的稳定性。 In order to elucidate the effect of the saturation of fatty acids composing triglycerides on cholesterol oxidation, the oxidation of cholesterol in tristearin (GTS) and triolein (GTO) was studied using gas chromatography-mass spectrometry , And tracking changes in peroxide value simultaneously. The results showed that the major oxidation products of cholesterol in GTS and GTO were 7α-hydroxycholesterol, 7β-hydroxycholesterol, 5,6β-epoxycholesterol, 5,6α-epoxycholesterol and 7-keto-cholesterol. Under the condition of 160 ℃, the oxidation products of cholesterol first increased and then decreased, the amount of unoxidized cholesterol decreased gradually. The maximum value of peroxide value (500.46 meq / kg) appeared at 1 h after heating in GTO, and the value of peroxide value in GTS was Heating 3 h maximum (401.30 meq / kg), then gradually decreased. Cholesterol did not oxidize in GTS at 110 ℃, and the peroxide value was also lower. The maximal value (278.43 meq / kg) appeared after 96 hours of heating. Cholesterol was almost completely oxidized in GTO, the peroxide value increased rapidly and the maximum The value appeared in heating 12 h (1486.88meq / kg), then gradually decreased. Overall, cholesterol was stable in GTS compared to GTO at 160 ° C and 110 ° C, and the peroxide value was delayed and produced less, so the saturated fatty acid triglyceride was more helpful to maintain Cholesterol at high temperature stability.