酶水解-连续流动法测定烟草中的淀粉含量

建立了一种酶水解-连续流动法测定烟草中淀粉含量的方法,将样品先用85%乙醇去除水溶性糖,沸水浴加热使淀粉糊化,加入强碱破坏淀粉的结构,然后在淀粉葡萄糖苷酶（AGS）的作用下,淀粉将在pH=4.6的条件下水解生成葡萄糖,生成的葡萄糖使用连续流动法测定含量,推算出淀粉含量.方法回收率为96.6%,变异系数为1.52%～4.08%,说明该方法较为稳定、准确.比较了酶水解-连续流动法、酶水解法（ISO方法）、酸水解法和碘显色法测定烟草中淀粉含量的差异,并使用酶水解-连续流动法测定了国内外18个烟草样品中淀粉的含量.

Determination of starch in tobacco with enzymatic hydrolysis-continuous flow method

An enzymatic hydrolysis-continuous flow method to determine the starch in tobacco was developed. The water-soluble sugars were extracted in 85% ethanol solution before the sample was heated in boiling water bath for the gelation of starch. In the presence of enzyme amyloglucosidase (AGS), the starch was hydrolyzed to glucose when the pH is 4.6. The content of the starch can be calculated by measuring the content of glucose with continuous flow method. The recovery of the starch was 96.6% and the relative standard deviation (n=7) ranged from 1.52% to 4.08%. In contrast with enzymatic method (ISO 8451:91), conventional acidic hydrolysis method, and iodine colorimetric method, enzymatic hydrolysis-continuous method has the advantages of stability and exactness. The content of starch in 18 tobacco samples was also determined.