高纯度单月桂酸甘油酯的酶催化合成工艺

Enzymatic Process for Synthesis of Extremely Pure Glycerol Monolaurate

摘要:

采用脂肪酶Novozyme 435催化月桂酸甲酯与甘油进行酯交换反应制备单月桂酸甘油酯。以反应体系中单月桂酸甘油酯的质量分数为考察指标，通过单因素实验和正交实验对酶催化合成工艺进行优化，得到最佳的工艺条件为：底物摩尔比1:5，底物质量分数20%，反应温度55 ℃，酶添加量为7%，初始含水量为20%，转速为100 r/min，反应时间1 h，在该条件下，体系中单月桂酸甘油酯的质量分数为71.86%。经提纯后终产物中单月桂酸甘油酯的质量分数高于95%，最高可达98.76%，而双月桂酸甘油酯的质量分数低于5%。在最佳工艺条件下，酶重复使用6次，单月桂酸甘油酯的质量分数从71.75%降至68.36%，其催化性能无显著降低。

Abstract:

Novozyme 435 was employed as biocatalyst for the transesterification of methyl laurate and glycerol in t-butanol producing glycerol monolaurate (GML). Emzymatic synthesis process was optimized by single-factor and orthogonal experiment using the content of glycerol monolaurate in the reaction system as the index. The results show that the optimum conditions were as follows: substrate molar ratio 1:5，substrate concentration 20%，reaction temperature 55 ℃，enzyme amount 7%，water content 20%，rotation rate 100 r/min，and reaction time 1 h. The content of glycerol monolaurate in the reaction system was 71.86% under the optimal synthesis conditions，After the recycle of unreacted methyl laurate，After purification the content of glycerol monolaurate in the final product was higher than 95%，with the maximum content 98.76%，while the content of glycerol dilaurate (GDL) was no more than 5%. Under the optimal conditions, the content of glycerol monolaurate decreased to 68.36% after being reused for six times, which was 71.75% in the first test.