玉米油酶法合成甘油二酯工艺优化研究

以玉米油、甘油为原料,在无溶剂体系中用固定化脂肪酶Lipozyme TL IM催化合成甘油二酯,通过单因素试验和响应面试验研究底物摩尔比(亚油酸/甘油)、反应温度、反应时间、酶质量分数和初始水质量分数等因素对亚油酸转化率的影响。得出:反应温度、底物摩尔比、反应时间、酶质量分数对亚油酸转化率影响较大;影响酯化反应中亚油酸转化率的主次因素依次为反应温度、底物摩尔比、反应时间、酶质量分数;最佳工艺条件为亚油酸和甘油的摩尔比为2.10∶1,反应温度为61.16℃,反应时间为12.17 h,酶质量分数为20.09%,亚油酸转化率达到75.69%。Lipozyme TL IM连续反应3批次,其相对酶活仍有65.7%。

Research on process optimization of lipase-catalyzed synthesis of deglyceride from corn oil

Enzymatic synthesis of diglyceride was studied by using the immobilized lipase Lipozyme TL IM as the catalyst,corn oil and glycerol as substrates in a solventfree system.Single factor test and response surface methodology(RSM) was used to evaluate the effect of molar ratio of linoleic acid and glycerol,reaction temperature,reaction time,enzyme amount and the ratio of water to the substrates on the conversion rate of linoleic acid.The result of research shows:reaction temperature,reaction time,molar ratio of linoleic acid and glycerol,enzyme amount have important effects on the conversion rate of the linoleic acid;and I get the primary and secondary order of each factor:reaction temperature > molar ratio of linoleic acid and glycerol > reaction time > enzyme amount;The optimum conditions are as follows:molar ratio of linoleic acid and glycerol is 2.10∶1,reaction temperature is 61.16℃,reaction time is 12.17 h and enzyme amount is 20.09%.Under these conditions,the conversion rate of the linoleic acid is 75.69%.The residual activity of lipase is still about 65.7% after being continuously reacted for 3 batches.