【摘要】 以脂肪酶Novozym 435催化维生素C和乳酸乙酯转酯合成维生素C乳酸酯。采用基于四因素五水平的中心组合设计实验的响应曲面法,分析了温度(30~70℃)、酶量(10~30 mg)、维生素C质量浓度(9.36~28.07g/L)和反应时间(24~72 h)以及它们的交互作用对维生素C乳酸酯产率的影响。获得的最佳实验条件为:温度50℃,维生素C的质量浓度18.71 g/L,脂肪酶质量20 mg和反应时间48 h。在最佳条件下,维生素C乳酸酯的预计产率为71.20%,与实际产率71.12%符合较好。更多还原

【Abstract】 Vitamin C lactate was synthesized through transesterification of ethyl lactate and vitamin C catalyzed by enzyme Novozym 435(from Candida antarctic lipase B).Response surface methodology(RSM) based on a five-level,four-variable central composite rotatable design(CCRD)was used to evaluate the interactive effects of temperature(30~70 ℃),amount of enzyme(10~30 mg),substrate concentration(vitamin C,9.36~28.07 g/L) and reaction time(24~72 h)on the percentage yield of vitamin C lactate.The optimum conditions derived via RSM were:temperature 50 ℃,amount of enzyme 20 mg,substrate concentration 18.71 g/L and reaction time 48 h.Under the optimum conditions,the actual experimental yield was 71.12% which compared well to the predicted value of 71.20%.更多还原