外源植酸酶对菜籽粕中植酸的酶解条件优化

Optimizing enzymatic hydrolysis condition of phytate in rapeseed meal by extraneous phytase

本研究对外源植酸酶降解菜籽粕中植酸的酶解条件进行优化。首先利用单因素方法研究植酸酶使用量对菜籽粕中植酸的影响,确定植酸酶的最佳添加量,在此基础上采用响应面法研究时间、温度、料水比三个因素对酶解效果的影响,确定最佳的时间、温度、料水比。结果表明:植酸酶的用量显著影响菜籽粕中的植酸含量(P<0.01),在本研究设定范围内,植酸酶的最佳使用量为2000 U/kg;时间(P<0.01)、温度(P<0.05)和料水比(P<0.01)三个因素均可显著影响菜籽粕中的植酸含量,最佳酶解条件为时间3 h,温度30℃,料水比0.5,此时,菜籽粕的植酸含量为19.6 mg/g干物质。由此可见,在适宜的处理条件下,植酸酶能够有效地降低菜籽粕中的植酸含量,提高菜籽粕的营养价值。

The enzymatic hydrolysis condition of phytate in rapeseed meal by extraneous phytase was analyzed and optimized.The optimum amount of phytase was determined firstly by single factor test.Then,the response surface method with Box-Benhnken design was applied to qualify the effect of time,temperature and ratio of substrate to water on phytate degradation in rapeseed meal,and to optimize these three factors.The results showed that：the amount of phytase could significantly affect the phytate degradation（P 0.01）,and the optimum amount of phytase was 2000 U/kg in terms of the experimental design of this study.The duration（P 0.01）,temperature（P 0.05）and ratio of substrate to water（P 0.01） could significantly affect the phytate degradation.The optimal conditions derived from response surface methodology for phytase treatment were：duration 3 h,temperature 30 ℃,and ratio of substrate to water 0.5.The minimum content of phytate in rapeseed meal was 19.6 mg/g dry matter.The results indicated that the external phytase used for degradation of phytate in rapeseed meal could improve its value.