中文摘要：

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0．9404，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91．34U／g、温度71．7℃、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％。

英文摘要：

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℃ 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 %.