超声波辅助脂肪酶水解红花籽油条件优化与动力学

Conditions Optimization and Kinetics Analysis of Lipase Hydrolysis Assisted by Ultrasonic of Safflower Seed Oil

本文通过单因素实验,分别考察超声时间、超声温度、p H、酶添加量对脂肪酸水解率的影响,结合响应面实验优化超声波辅助脂肪酶水解红花籽油的工艺条件,并比较超声波辅助酶解和水浴酶解中米氏常数及表观动力学的变化。结果表明:最佳酶解条件为:超声时间10 h,超声温度28℃,p H7.0,米曲霉脂肪酶添加量为280 U/g,水油比1.6∶1(v/v),此时红花籽油的水解率达到94.47%。对其进行表观动力学研究,测得超声波辅助脂肪酶水解红花籽油的米氏常数Km=4.63 m L/g,表观活化能Ea=2.05 k J/mol,比水浴酶解条件下米氏常数Km=14.93 m L/g和表观活化能Ea=2.40 k J/mol均降低,证明超声波辅助脂肪酶能促进红花籽油的水解。

In this paper, the effects of ultrasonic time, ultrasonic temperature, pH and enzyme addition on the hydrolysis rate of fatty acid were investigated by single factor test.The lipase hydrolysis conditions of safflower seed oil assisted by ultrasonic were optimized by the response surface test. The changes of kinetic parameters Km and apparent kinetics in ultrasonic assisted enzymatic hydrolysis and water bath hydrolysis were compared.The optimized parameters were as follows ：ultrasonic time 10 h, ultrasonic temperature 35 ℃ ,pH7.0, enzyme dosage of 220 U/g, water/oil ratio of 1.6： 1.Under this condition, the hydrolysis rate was 94.47 % .In addition, the apparent kinetic parameters Km and Ea of safflower seed oil hydrolysis assisted by ultrasound were respectively measured as 4.63 mL/g and 2.05 kJ/mol, which were less than those of controlled trial 14.93 mL/g and 2.40 kJ/mol and suggested that ultrasonic could facilitate the lipase hydrolysis of safflower seed oil.