Studies on the properties of antioxidative emulsifier in aqueous and emulsion systems

利用固定化南极洲假丝酵母脂肪酶，将抗坏血酸和脂肪酸在丙酮中缩合，合成了抗坏血酸酯。辛酰基抗坏血酸降解水溶液中儿茶素的速率常数k与抗坏血酸浓度的依赖关系明显不同。抗坏血酸或辛酰基抗坏血酸降低了儿茶素的稳定性，但降解的k值随着柠檬酸浓度的增加而降低。测定了油滴亚油酸甲酯在O/W乳状液中与抗坏血酸或抗坏血酸酯混合时的氧化过程，并考察了它们的抗氧化性能。

Acyl ascorbates were synthesized by the condensation of ascorbic and fatty acids in acetone using an immobilized lipase from Candida antarctica. The dependency of the rate constant, k, for the degradation of catechin in aqueous solution with octanoyl ascorbate on the concentration of the ascorbate was obviously different from that with ascorbic acid. The stability of catechin was reduced by ascorbic acid or octanoyl ascorbate, although the k value for degradation decreased with increasing citric acid concentration. The oxidation process of methyl linoleate as an oil droplet in the O/W emulsion with ascorbic acid or acyl ascorbate was measured, and their antioxidative properties were examined.