甘油二酯的酶法合成工艺研究

摘要

The lipase-catalyzed esterification of glycerol and caprylic acid to produce deglyceride (DAG) in a solvent free system was investigated.Among the three immobilized lipases, Novozyme 435 resulted in the highest conversion rate of caprylic acid and the highest yield of DAG.This enzyme was selected to further study the effects of substrate ratio, reaction temperature, enzyme loading and dehydration methods, respectively.Moreover,the parameters were optimized by the response surface method.The optimal conditions were as follows;the molar ratio of caprylic acid to glycerol 1.99∶1.reaction temperature 51.5 ℃, enzyme loading 3.05％ and reaction time 6.29 h.Under these conditions, the DAG yield was up to 71.9％.%以固定化脂肪酶为催化剂,研究无溶剂体系下甘油和辛酸直接酯化合成甘油二酯工艺.在选用的3种脂肪酶中,发现Novozyme 435催化效果最好.以Novozyme 435为催化剂,考察了底物摩尔比、温度、反应加酶量以及脱水方式等因素对辛酸转化率和甘油二酯含量的影响,并通过响应面法优化了工艺参数,获得酶法合成甘油二酯的最优工艺条件:酸油比1.99:1,反应温度51.5℃,加酶量3.05%,反应时间6.29 h.在最优条件下,甘油二酯的含量达到71.9%.