为进一步加深对糯小麦淀粉特性的认识,选用2个糯小麦和2个普通非糯小麦品种为材料,利用激光粒度分析仪分析了糯小麦完熟籽粒中淀粉的粒度分布特征,及其与普通非糯小麦品种的差异。结果表明,糯小麦淀粉粒的粒径分布范围为1.0~43.7μm,不同粒径淀粉粒的数目比例分布呈单峰曲线变化,体积和表面积分布均呈双峰曲线变化;糯小麦籽粒中存在2种类型淀粉粒,即A型大淀粉粒(直径≥10μm)和B型小淀粉粒(直径〈10μm),B型淀粉粒的数目、体积和表面积比例均高于A型淀粉粒。与普通非糯小麦相比,糯小麦籽粒中B型小淀粉粒的数目、体积和表面积比例较高,淀粉粒的平均粒径和中位粒径较大。糯小麦与普通非糯小麦不同粒径淀粉粒的数目、体积和表面积比例分布曲线存在差异。糯小麦B型淀粉粒处的峰高显著高于普通非糯小麦,A型淀粉粒处的峰值低于后者。糯小麦体积和表面积分布中B型淀粉的峰值粒径显著小于普通非糯小麦。
For further understanding the properties of waxy wheat starch,we selected two waxy wheat cultivars,using two non-waxy wheat cultivars as control,to study the starch granule size distribution characteristics,which were detected by a single wavelength Beckman Coulter LS 13 320 laser diffraction particle size analyzer.The results indicated that the range of starch granule diameters in mature grain of waxy wheat was from 1.0 to 43.7 μm.Waxy wheat grain had a unimodal curve in starch granule number distribution,and the distribution of both starch granule volume and surface area showed a bimodal curve.There were two types of starch granules,A-type granules with big and diameter ≥10 μm and B-type granules with small and diameter 10 μm,which was same as non-waxy wheat.However,as to waxy wheat,the number,volume and surface area ratios of B-type granules were higher than those of A-type granules.Compared with non-waxy wheat cultivars,waxy wheat cultivars had much higher ratios of B-type starch granule in number,volume and surface area distributions.There were marked differences between waxy wheat and non-waxy wheat in the characteristics of starch granule distribution curve.The peak heights in B-type granules of waxy wheat were greater than those in non-waxy wheat.Nevertheless,the peak heights in A-type granules of waxy wheat were lower than those in non-waxy wheat.The peak diameters in B-type granules of waxy wheat in volume and surface area distribution curves were significantly smaller than those of non-waxy wheat.