玉米籽粒胚乳淀粉粒度分布特征及其与黏度参数的关系

Relationship Between Starch Granule Size Distribution and Starch Viscosity Parameters in Corn Kernels

目的:分析玉米成熟期籽粒胚乳淀粉粒度分布特征与淀粉黏度参数间关系。方法:以华皖681(HW681)等7个玉米品种为材料,分析成熟期玉米籽粒胚乳淀粉粒度分布特征与黏度参数。结果:成熟期玉米籽粒淀粉粒体积、数目、表面积分布分别呈双峰、单峰与双峰曲线,其中体积分布曲线峰值出现在1.5、16μm左右,低谷值出现在3μm左右。以3、16μm为界限,将玉米胚乳淀粉粒分为小型(粒径<3μm)淀粉粒、中型(粒径3～16μm)淀粉粒与大型(粒径>16μm)淀粉粒。玉米小型、中型与大型淀粉粒体积百分比分别为9.29%～10.35%、44.47%～8.05%和31.8%～46.25%;小型淀粉粒数目百分比99.5%以上,中、大型淀粉粒仅占0.5%。可见虽然小淀粉粒体积百分比较小,但玉米胚乳淀粉粒绝大多数是由粒径<3μm小淀粉粒组成。不同品种淀粉黏度参数存在显著差异。中、小型淀粉粒体积百分比与淀粉峰值黏度、稀懈值呈显著或极显著负相关,大型淀粉粒体积百分比与淀粉峰值黏度、稀懈值呈显著或极显著正相关。结论:与中、小型淀粉粒相比,玉米成熟期籽粒胚乳中大型淀粉粒峰值黏度、稀懈值较高。

Objective:To analyze the relationship between the starch granule size distribution and starch viscosity parameters in corn kernels at maturity.Methods:Seven corn cultivars such as Huawan 681(HW681)were used to analyze the starch granule size distribution,and starch viscosity parameters in maize endosperm at the maturity.Results:A bimodal curve was found in the volume and surface area distribution of starch granules,and a typical population curve was observed for the number distribution in corn kernels.The starch granules were divided into three groups:small(<3μm),medium(3-16μm)and large(>16μm)starch granule groups.Proportions of granules<3μm,3-16μm and>16μm were in the range of 9.29%~10.35%,44.47%~8.05%and 31.8%~46.25%of total volume,respectively.And proportions of starch granules<3μm were in the range of 99.95%of total number.It indicated that the corn endosperm starch granules are mainly composed of small starch granules of<3μm.The peak viscosity and breakdown were significant negative correlated to volume percentage of granule 3-16μm,and significant positive correlated to volume percentage of granule>16μm.Conclusion:These indicated that the large granules>16μm have peak viscosity and breakdown compared with small granules<16μm in corn kernels.