微量成分形成的反胶束对亚麻籽油氧化稳定性的影响

Effects of Reverse Micelles Formed by Minor Components on Oxidative Stability of Flaxseed Oil

以富含α-亚麻酸的亚麻籽油为研究对象,测定多种微量成分(磷脂、油酸、β-谷甾醇、二酰基甘油)在stripped亚麻籽油中的临界胶束浓度,并研究反胶束的形成对亚麻籽油氧化稳定性以及生育酚抗氧化活性的影响。结果表明,磷脂是形成反胶束的重要组分,其临界胶束浓度为125μmol/kg;与对照组相比,低浓度(低于临界胶束浓度)微量成分对亚麻籽油的热稳定性无显著影响,但形成反胶束后则能显著降低油脂的起始氧化温度(约12%)以及氧化诱导时间(约33%),增加贮藏过程中氢过氧化物(约36%)、丙醛(约13%)和己醛(约200%)的含量,显示出促氧化活性;与对照组相比,生育酚的添加能抑制油脂氧化进程,但反胶束的形成使油脂中氧化产物浓度高于对照组,降低了生育酚的抗氧化活性。因此控制亚麻籽油中反胶束的形成将有助于油脂氧化稳定性,为富含n-3多不饱和脂肪酸油脂的稳态化控制提供新的策略与途径。

In this research,the critical micelle concentrations(CMC)of various minor components(phospholipids,oleic acid,β-sitosterol and diglyceride(DAG))in stripped flaxseed oil were determined,and the effects of the formation of reverse micelles on the oxidative stability of the flaxseed oil and the antioxidant activity ofα-tocopherols were studied.The results showed that phospholipid(DOPC)was an important component for the formation of reverse micelles,and its critical micelle concentration was 125μmol/kg oil.Compared with the control group,the addition of low concentrations(<CMC)of microcomponents had no significant effect on the thermal stability of flaxseed oil.But the formation of reverse micelles could reduce the initial oxidation temperature(~12%)and oxidation induction time(~33%)of the oil,and increase the concentrations of hydroperoxide(~36%),propionaldehyde(~13%)and hexanal(~200%)during storage,showing prooxidant activity.Compared with the control group,α-tocopherol inhibited the oxidation of oil,but the formation of reverse micelles exhibited higher oxidation product concentration,reducing the antioxidant activity ofα-tocopherol.Therefore,controlling the formation of reverse micelles in flaxseed oil is beneficial to improve its oxidative stability,and can provide a new strategy and approach for the steady-state control of oil rich in n-3 polyunsaturated fatty acids(PUFA).