小麦抗性糊精制备工艺优化、结构表征及其体外消化

Process Optimization,Structural Characterization and in vitro Digestibility of Wheat Resistant Dextrin

为探究酸热法制备小麦抗性糊精的最佳制备工艺、结构及其消化特性,该试验以小麦淀粉为原料,以抗性糊精得率为指标,通过单因素和响应面试验对小麦抗性糊精制备酸热条件进行优化,对其结构进行表征,并考察其体外消化特性。抗性糊精的最佳酸热工艺条件为盐酸浓度0.075 mol/L、酸热温度180℃、酸热时间95 min,经α-淀粉酶、淀粉葡糖苷酶酶解后抗性糊精得率为(43.83±0.08)%,抗性糊精含量为(86.99±0.23)%。抗性糊精微观结构形态呈无规则小碎片状,表面富有孔洞,不再具有小麦淀粉“A”型晶体结构,没有新的官能团产生,抗性糊精重均分子质量为7.39×10^(3)g/mol;通过体外模拟消化试验表明小麦抗性糊精水解率远小于小麦淀粉,抗性糊精具有良好的抗消化性。

This study aimed to explore the optimal preparation process,and structure and digestion properties of wheat resistant dextrin prepared by the acid-heating method.With wheat starch as the raw material and the yield of resistant dextrin as the index,the preparation process of wheat resistant dextrin was optimized by single factor and response surface experiments,and the structural characterization and in vitro digestion properties were investigated.The results showed that the optimal preparation conditions were as follows:the concentration of hydrochloric acid of 0.075 mol/L,acid-heating temperature of 180℃,and acid-heating time of 95 min.After enzymolysis byα-amylase and amyloglucosidase,the yield of resistant dextrin was(43.83±0.08)%and the content of resistant dextrin was(86.99±0.23)%.The microstructure of the resistant dextrin was irregular and fragmented with the surface full of holes,and there was no A-type crystalline structure of wheat starch.No new functional groups were generated,and the weight-average molecular weight of the resistant dextrin was 7.39×10^(3) g/mol.The results of in vitro simulated digestion experiment showed that the hydrolysis rate of wheat resistant dextrin was much lower than that of wheat starch,and resistant dextrin had good anti-digestive properties.