旋光法测定马铃薯淀粉含量最佳水解时间的确定

Optimal Hydrolysis Time for Potato Starch Determination Using Polarimetry

淀粉含量的高低是评价马铃薯品质的重要指标之一.测定马铃薯淀粉含量的方法较多,其中旋光法所用仪器简单,试剂种类少,操作简便、快速,重现性好,应用广泛.为确定旋光法测定马铃薯块茎淀粉含量的最佳水解时间,以本地主栽品种‘新大坪’、‘陇薯3号’、‘陇薯6号’为试验材料,设置10,15,20,25,30 min 5个处理时间,3次重复试验,比较旋光度及淀粉含量.结果表明,水解时间为15 min时,旋光度值最大,随水解时间延长,旋光度值反而减小.由此确定,旋光法测定马铃薯块茎淀粉含量的最佳水解时间为15 min.

Starch content of potato is one of the key indexes for evaluating its quality. There are many methods for testing potato starch content, and polarimetry method employs simple devices and a few chemicals and operate sim-ply and quickly with great replication and wild applications. In order to confirm the optimal hydrolysis time of pota-to tuber starch using polarimetry method, local potato varieties of‘Xindaping’,‘Longshu 3’and‘Longshu 6’ were used as raw materials, and 10, 15, 20, 25 and 30 min were employed to compare optical rotation and starch content with three duplicates. The results showed that the optical rotation value was the largest when the hydrolysis duration was 15 min and then the value decreased with hydrolysis time. Therefore, the optimal hydrolysis time for determination of potato starch content should be 15 min.