超声波辅助脂肪酶水解茶叶籽油条件的优化与动力学研究

摘要

研究无溶剂体系中超声波辅助脂肪酶水解茶叶籽油,通过单因素试验和正交试验获得最佳酶解条件为:油水比2∶3(g:mL),加酶量为茶叶籽油质量的4.5％,缓冲液初始pH 8.5,超声波处理温度50℃,搅拌转速300 r/min,反应时间19.5 h.在此条件下,茶籽油的水解率达到72.25％.对其进行了表观动力学研究,测得超声波辅助脂肪酶水解茶叶籽油的米氏常数Km为0.053 mL/g,表现活化能Ea为14.05 kJ/mol,比无超声波辅助酶解的Km=4.556 mL/g和Ea=30.73 kJ/mol均降低,说明超声波能促进茶叶籽油的酶解.%Tea seed oil hydrolysis catalyzed by lipase under ultrasound irradiation was performed in solvent-free system.The optimized parameters were obtained by single factor and orthogonal test design as follows:oil-water ratio 2∶3 (g∶ mL),content of Lipase 4.5％ (as oil wt),initial pH of buffer 8.5,temperature of ultrasonic bath 50 ℃,mechanical agitation speed 300 r/min,reaction time 19.5 h.Under this condition,the hydrolysis rate was 72.25％.In addition,the apparent kinetic parameters Km and Ea of tea seed oil hydrolysis assisted by ultrasound were respectively measured as 0.053 mL/g and 14.05 kJ/mol,which were less than those of controlled trial 4.556 mL/g and 30.73 kJ/mol and suggested that ultrasonic bath could facilitate the hydrolysis of tea seed oil catalyzed by lipase.