It possesses affinity vis-a-vis the oxidation of the substance which possesses the oils and fats or the divination oxidation characteristic unsaturated bond which contain the unsaturated fatty acid, it designates that the anti- oxidizer of the natural thing origin which possesses the oxidation prevention effect where safety is high, stabilizes is offered as topic, it contains emulsification ones of the ester of the natural high-level polyunsaturated fatty acid which possesses the bis allylic position hydrogen of 2 or more, as the anti- oxidation active ingredient it solves the unsaturated fatty acid, with the anti- oxidizer for the substance which possesses the unsaturated fatty acid content oil and fat, or divination oxidation characteristic unsaturated bond. linolenic acid and arachidonic acid, EPA, like dokosapentaen acid or DHA any emulsification things of the ester of the natural high-level polyunsaturated fatty acid which possesses the bis allylic position hydrogen of 2 or more have anti- oxidation action the unsaturated fatty acid, the unsaturated fatty acid content oils and fats, or vis-a-vis the substance which possesses divination oxidation characteristic unsaturated bond. To use the eating and drinking item which includes the unsaturated fatty acid or the divination oxidation characteristic unsaturated bond content substance, as anti- oxidizer such as medicine, cosmetics and fodder it is possible the anti- oxidizer of this invention.不飽和脂肪酸を含有する油脂類、又は易酸化性の不飽和結合を有する物質の酸化に対して、親和性を有し、安全性が高く、安定した酸化防止効果を有する天然物由来の抗酸化剤を提供することを課題とし、2以上のビスアリル位水素を有する天然の高度多価不飽和脂肪酸のエステルの乳化物を抗酸化活性成分として含有する、不飽和脂肪酸、不飽和脂肪酸含有油脂、又は易酸化性の不飽和結合を有する物質用抗酸化剤によって解決する。α-リノレン酸、アラキドン酸、EPA、ドコサペンタエン酸、或いはDHAのように2以上のビスアリル位水素を有する天然の高度多価不飽和脂肪酸のエステルの乳化物は、不飽和脂肪酸、不飽和脂肪酸含有油脂類、又は易酸化性の不飽和結合を有する物質に対して、抗酸化作用を有する。本発明の抗酸化剤は、不飽和脂肪酸又は易酸化性の不飽和結合含有物質を含む飲食品、医薬、化粧品及び飼料等の抗酸化剤として用いることができる。
