螺杆挤压对马铃薯淀粉消化性及血糖指数的影响

目的研究螺杆挤压对马铃薯淀粉消化特性的影响。方法马铃薯淀粉经过螺杆挤压后(过程中淀粉未膨化),采用酶重量法测定挤压后抗性淀粉的含量变化情况,并通过模拟体外消化和动物实验评价挤压后淀粉的消化性能和餐后血糖上升速率。结果螺杆挤压后马铃薯淀粉中抗性淀粉的含量增加了1.08%,酶解时间为0~1.5 h时,马铃薯淀粉快速消化淀粉的含量减少,酶解时间为1.5~6.5 h时,抗性淀粉和慢消化淀粉的含量增加。挤压后的马铃薯淀粉在一定程度上可以降低小鼠的餐后血糖指数。结论螺杆挤压技术可以提高抗性淀粉和慢消化淀粉的含量,减缓餐后血糖上升速率,为马铃薯食品的深度开发提供一定的参考。

Effects of screw extrusion on digestibility and glycemic index of potato starch

Objective To investigate the effects of screw extrusion on the digestibility of potato starch. Methods After extruding potato starch by screw (starch was not expanded in the process), the content of resistant starch was determined by enzyme gravimetric method. The digestibility of starch after extrusion and the rate of blood glucose rise after meal were evaluated by simulated in vitro digestion and animal experiments. Results The content of resistant starch in potato starch was increased by 1.08%. When the enzymatic hydrolysis time was 0~1.5 h, the content of rapidly digested starch in potato starch was decreased, and when the enzymatic hydrolysis time was 1.5~6.5 h, the content of resistant starch and slowly digestible starch was increased. Potato starch after extruded could reduce the postprandial glycemic index to some extent. Conclusion Screw extrusion can improve the content of resistant starch and slow digestion starch, and slow down the rise rate of postprandial blood glucose, providing a certain reference for the in-depth development of potato food.