大环糊精制备条件的优化

采用Plackett-Burman设计筛选了4-α-葡萄糖基转移酶作用高直链玉米淀粉制备大环糊精的条件,同时采用Box-Behnken设计进行了优化。结果表明:加酶量、温度及时间3个因素能够显著影响大环糊精的产率,t-检验结果显示,Box-Behnken设计预测模型显著(P≤0.05),失拟项不显著(P≥0.05)。预测模型的相关系数R2为0.940 4,表明模型回归良好。用该预测模型预测得到的大环糊精的产率为56.58%,预测得到的最佳实验条件为加酶量91.34 U/g、温度71.7°C、时间6.8h。在该实验条件下测定得到的大环糊精的产率为55%,比优化前提高了2.3倍。制备得到的大环糊精经鉴定,聚合度为20～40,环状比例为47%。

Optimization of the Preparation of LR-CD

Plackett-Burman design was used to select reaction conditions for large ring cyclodextrin(LR-CD) preparation,and the significant factors were optimized by Box-Behnken design.Results showed that,enzyme,temperature and time were three significant factors,t-test showed that model of Box-Behnken design was significant(P≤0.05),and lack of fit was no significant(P≥0.05).The regression coefficient R2 was 0.9404,which was showed a good regression result.The predicted yield of LR-CD was 56.58%,and the predicted conditions were enzyme 91.34 U/g,temperature 71.7°C for 6.8 h.Validation test showed LR-CD yield of 55%,2.3 folds higher than initial yield.Identification results showed that the degree of polymerization was ranged from 20 to 40,the ratio of cyclic component was 47%.