酶法催化酯交换制备甘油二酯工艺优化研究

Optimization of enzymatic transesterification to prepare diglyceride

以大豆油和单甘酯为原料,在无溶剂体系中利用固定化脂肪酶Novozym 435催化合成甘油二酯。通过单因素实验和响应面实验研究反应温度、底物摩尔比、反应时间和酶添加量对甘油二酯含量的影响。结果表明:4个因素对甘油二酯含量影响的大小依次为反应温度、反应时间、酶添加量、底物摩尔比;合成甘油二酯的最佳工艺条件为大豆油与单甘酯摩尔比1∶2、酶添加量9%、反应温度83℃、反应时间6. 5 h,在此条件下甘油二酯含量为(51. 2±0. 2)%。

Diglyceride was synthesized from soybean oil and monoglyceride by immobilized Novozym 435 in a solvent-free system. The effects of reaction temperature,reaction time,enzyme dosage,and substrate molar ratio on the diglyceride content were studied by single factor experiment and response surface methodology. The results showed that the effect of reaction temperature on the diglyceride content was the greatest,followed by reaction time,enzyme dosage and substrate molar ratio. The optimal conditions were obtained as follows: molar ratio of soybean oil to monoglyceride 1∶ 2,enzyme dosage 9%,reaction temperature 83 ℃ and reaction time 6. 5 h. Under the optimal conditions,the diglyceride content was( 51. 2 ± 0. 2) %.