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讨论了以固定化的黑曲霉脂肪酶为催化剂,以抗坏血酸和棕榈酸甲酯为底物的酯交换反应及其影响因素。考察了反应温度、维生素C与棕榈酸的摩尔比、反应时间、溶剂的选择、酶量等因素对催化棕榈酸抗坏血酸酯反应的影响规律。结果表明,摇床转速200r/min、叔丁醇作溶剂、反应温度为55℃底物棕榈酸甲酯与Vc的摩尔比为2:1、反应时间为28h、脂肪酶浓度为4%,反应转化率为42.1%,产品纯度95%。
The immobilization of Aspergillus niger lipase as catalyst, the transesterification with ascorbic acid and methyl palmitate as substrate, and the influencing factors were discussed. The effects of reaction temperature, molar ratio of vitamin C to palmitic acid, reaction time, solvent selection and enzyme amount on the catalytic reaction of ascorbyl palmitate were investigated. The results showed that the molar ratio of substrate methyl palmitate to Vc was 2: 1, the reaction time was 28 h and the lipase concentration was 4% at a shaking speed of 200r / min with tert-butyl alcohol as the solvent. The reaction temperature was 55 ℃. Conversion rate of 42.1%, product purity 95%.