为揭示油脂自身氧化特点及其对α-生育酚抗氧化效能的影响,添加不同浓度的α-生育酚到菜籽油、花生油和芝麻油中并进行氧化,测定POV值、茴香胺值和总氧化值的变化。3种油脂的双键相对值的关系是芝麻油>菜籽油>花生油,所以推测芝麻油最易氧化。而结果表明菜籽油最易氧化,其次是花生油,芝麻油最稳定,因此油脂氧化及α-生育酚的抗氧化不仅与脂肪酸组成的双键数有关,还可能与非甘油酯成分如维生素、多酚类化合物等不皂化物有关。不同油脂α-生育酚的抗氧化效能不同,如α-生育酚的最佳抗氧化浓度在菜籽油、花生油和芝麻油中分别为200、100和25 mg/kg,即越稳定的油脂需要添加的α-生育酚越低,反之亦然;然而若添加的α-生育酚高于其最佳抗氧化浓度则促进油脂氧化。

The oxidative properties and stability of α-tocopherol were investigated. The different levels of α-tocopherol were added into rapeseed oil,peanut oil and sesame oil at 60℃ to determine the peroxide values,p-anisidne values and TOTOX values at different time periods. The analysis of fatty acid composition shows the relative double bonds value were decreased in the order of sesame oil > rapeseed oil > peanut oil. We predicted that the stability of sesame oil is the lowest. However,oxidation experiments showed rapeseed oil was the most sensitive one,followed by peanut oil,while sesame oil was most stable. These data indicate that beside the fatty acid composition,unsaponification compounds such as the vitamins,polyphenol compounds may also influence the oil oxidation. The antioxidation ability of α-tocopherol showed different in different oils. For example,the best concentration of α-tocopherol for rapeseed oil,peanut oil and sesame oil was 200,100 and 25 mg / kg,respectively. This shows that more α-tocopherol should be added in more sensitive oils,and vice versa. However,if the amount of α-tocopherol was added higher than the best antioxidative concentration,it can increase the oxidation.