无溶剂体系中共吸附固定化脂肪酶催化合成植物甾醇酯

以大孔树脂NKA吸附固定化脂肪酶为催化剂，以月桂酸和植物甾醇为反应物，在无溶剂体系中合成植物甾醇酯；以NKA为载体共吸附固定葡聚糖与酶，考察了反应温度、底物摩尔比、糖种类及葡聚糖添加量和反应时间对酶催化性能的影响. 结果表明，在酸/醇摩尔比6:1、葡聚糖与酶共同吸附固定时分子量为10 kDa的葡聚糖添加量为酶量7.5%的条件下，60℃下反应12 h，酯化率高达96.2%，酯化反应时间比简单吸附固定化酶缩短4 h.

Synthesis of Phytosterol Esters Catalyzed by Immobilized Lipase in Solvent-free System

The aim of this work is to synthesize lauric acid phytosterol esters by lipase in solvent-free system. The lipase was immobilized on macroporous resin NKA, with addition of dextran. The reaction conditions were optimized. The results showed that under the optimized conditions of a molar ratio of lauric acid to phytosterol of 6:1, 7.5% dextra of molecular weight 10 kDa and the reaction temperature of 60℃ in solvent-free system, the esterification rate reached 96.2% after 12 h. The reaction time of the synthess of phytosterol esters decrease 4 h comparing with the immobilized lipase on a macroporous resin.