稻米直链淀粉含量测定方法研讨

通过标准碘比色法与改良碘比色法的比较认为改良碘比色法的优点是:既可测定精米粉或糙米粉等粉体材料也可测定精米粒和糙米粒等粒体材料,能将样品的直链淀粉更完全地分离出来,测试误差小,但需时间较长。相同品种不同类型样品直链淀粉的含量测定结果:精米粒>精米粉和糙米粒>糙米粉。测试精米粒或精米粉时宜选择强碱 KOH,而测试糙米粒或糙米粉时宜选择强碱 NaOH。样品量以100mg 为宜,但不足100mg 时进行品种间的比较仍可考虑采用。

Studies on the analyzing method of amylose contents in rice grain

Standard amylose procedure and modified amylose procedure were compared in the paper.There are following advantages in modified arnylose procedure.not only milled or brown rice powder but also milled or brown rice grains can be analyzed and the testing standard differences are much smaller.The order of amylose content (AC)of different type samples in a variety was:milled rice grain>milled rice powder and brown rice grain>brown rice powder.KOH should be used while analyzing milled rice grain or powder,and NaOH should be used while analyzing brown rice grain or powder should chose.100 mg sampling weight is better,but less than 100 mg can also be used when comparing varietal amylose content.