灌浆期遮阴对小麦胚乳淀粉粒度分布及糊化特性的影响

Effect of Shading at Grain Filling Stage on Particle Size Distribution and Pasting Properties of Wheat Endosperm Starch

为了解灌浆期遮阴对小麦胚乳淀粉粒度分布及淀粉糊化特性的影响,研究了灌浆期对扬麦13、宁麦13和烟农19进行30%遮阴后籽粒的淀粉粒度分布与糊化特性的变化。结果表明,小麦灌浆期遮阴显著降低了<10μm的B型淀粉粒体积和表面积占比,增加了>10μm的A型淀粉粒的体积和表面积占比,其中A型淀粉粒中主要增加了10~20μm淀粉粒的体积和表面积占比;遮阴处理对淀粉粒数目分布无显著影响。遮阴处理后,峰值粘度、低谷粘度、稀懈值、最终粘度、回升值等糊化参数指标均显著降低。小麦籽粒硬度、容重、出粉率等指标也因遮阴处理而显著降低。综上所述,遮阴处理改变了小麦籽粒淀粉粒粒度分布,降低了淀粉糊化参数和加工品质。

In order to study the effects of shading on the starch granule size distribution and starch pasting properties of wheat endosperm,three wheat varieties:Yangmai 13,Ningmai 13 and Yannong 19 were treated with 30%shading during grain filling stage.The results showed shading at the grain filling stage significantly reduced the volume and surface area percentage of B-type starch granules(<10μm),but increased the volume and surface area percentage of A-type starch granules(>10μm).Among A-type starch granules,the volume and surface area of starch granules ranging from 10 to 20μm were mainly increased.Shading treatment has no significant effect on the number distribution of starch granules.After shading treatment,peak viscosity,trough viscosity,breakdown,final viscosity and retrogradation value were significantly reduced.The primary processing quality,such as wheat grain hardness,test weight and flour yield were also significantly reduced by shading treatment.Shading treatment changed the size distribution of wheat grain starch,and reduced the pasting parameters and primary processing quality of starch.