探究了固定化脂肪酶Lipozyme TL IM催化单甘酯与油酸进行酯化反应制备1,3-甘油二酯的可能性,考察了溶剂、水活度、反应温度、底物摩尔比以及溶剂用量对甘油二酯产率及脂肪酶1,3-位置选择性的影响.在优化的实验条件(45℃,1.5 g Lipozyme TL IM,油酸与单甘酯摩尔比1.5∶1,6.0 g三氯甲烷,水活度为0.33)下,反应6 h时,甘油二酯产率可达80%,其中1,3-甘油二酯产率高达92%以上.Lipozyme TL IM循环使用5次后,甘油二酯产率及脂肪酶选择性无明显下降.
The potential of using lipase Lipozyme TL IM-mediated esterification of oleic acid with monoglyceride for 1,3-dioleoylglycerol( DO) preparation was explored and the effects of solvent,water activity,temperature,molar ratio of oleic acid to monostearin( MO) and the solvent quantity on the DO yield and 1,3-positional selectivity of the lipase were investigated systematically. Under the optimum conditions( 45 ℃,1. 5 g of Lipozyme TL IM,molar ratio of oleic acid to MO is 1. 5 ∶ 1,6. 0 g chloroform,and water activity is 0. 33),a total DO yield of 80% could be achieved with the content of 1,3-DO over 92%. Lipozyme TL IM showed rather good operational stability in the system and there was no obvious reduction in lipase's activity and selectivity even after being continually used for 5 batches.