α-生育酚在玉米油、大豆油和茶油中的抗氧化动力学研究

Antioxidation kinetics of α-tocopherol in corn oil,soybean oil and oil-tea camellia seed oil

进行了α-生育酚在玉米油、大豆油和茶油中的抗氧化动力学研究。添加不同量的α-生育酚到纯化玉米油、大豆油和茶油中,进行Schaal烘箱氧化实验,定期测定过氧化值和茴香胺值,并计算总氧化值。根据一阶动力学反应或零阶动力学反应所得回归系数可以得出,过氧化值、茴香胺值、总氧化值与氧化时间的拟合方程是成立的,且生成氢过氧化物的速率常数可代替油脂的氧化速率常数,从而得到在不同α-生育酚添加量下的油脂氧化速率常数。结果表明:当α-生育酚添加量低于最适添加量时,随着α-生育酚添加量升高,氧化速率常数会逐渐变小,表明α-生育酚的抗氧化效能不断增强。当α-生育酚添加量高于最适添加量后,随着α-生育酚添加量升高,氧化速率常数会逐渐增大直至大于空白样的氧化速率常数,表明α-生育酚的抗氧化效能不断减弱直至出现促氧化现象。因此,通过油脂氧化速率常数探究不同添加量的α-生育酚在玉米油、大豆油和茶油中的抗氧化效能是可行的。

The antioxidation kinetics of α-tocopherol in corn oil,soybean oil and oil-tea camellia seed oil were studied. Different dosages of α-tocopherol were added into pure corn oil,soybean oil and oil-tea camellia seed oil,then Schaal oven oxidation experiment was conducted,and the peroxide values and p-anisidne values were determined regularly and total oxidation values were calculated. The regression coefficient from first-order kinetics reaction or zero-order kinetics reaction indicated that the fitting equations of peroxide values,p-anisidne values and total oxidation values with oxidation time were established,and the rate constant of hydroperoxides compounds formation could substitute the oxidation rate constant of oil,thus the oxidation rate constants of oil added with different dosages of α-tocopherol were obtained. The results indicated that the oxidation rate constant decreased gradually with the dosage of α-tocopherol increasing when the dosage of α-tocopherol was lower than the optimal dosage,which indicated that the antioxidant efficiency of α-tocopherol was growing. On the contrary,the oxidation rate constant increased gradually until exceeding that of the blank with the dosage of α-tocopherol improving when the dosage of α-tocopherol was higher than the optimal dosage,which indicated that the antioxidant efficiency of α-tocopherol was weakening until prooxidation appeared. Therefore, it was feasible to explore the antioxidant efficiency of different dosages of α-tocopherol in corn oil,soybean oil and oil-tea camellia seed oil through the oxidation rate constant.