不同直链淀粉含量大米淀粉性质的研究

Study on properties of rice starches with different amylose content

以4种不同直链淀粉含量的米淀粉为原料,采用扫描电镜(SEM)、全波长自动扫描仪,质构仪等对其颗粒形貌、淀粉-碘复合物性质、ATP指标及透明度性质进行观察研究。结果表明,不同直链淀粉含量的大米淀粉颗粒形貌差异不大,均呈现不规则多边形,表面不光滑;随着直链淀粉含量的增加,淀粉颗粒的平均链长和聚合度不断增大,优糯3号淀粉颗粒内部短链数量较多,随着直链淀粉含量的增加淀粉颗粒内部的长短链比率逐渐趋近于1;淀粉糊的质构性质测定显示出淀粉糊的硬度、胶着性和咀嚼性随着直链淀粉含量的增加呈现出明显的上升趋势,弹性随着直链淀粉含量的增加变化不大,而凝胶的粘聚性明显下降;糊透明度随直链淀粉含量的增大而不断降低。

The morphology,starch- iodine complex,texture properties and transparency of rice starches with different amylose content were studied with scanning electron microscope（ SEM）,full- wavelength automatic scanners and texture analyzer. Generally,all the rice starch granules display very similar polyhedral shapes and smooth surface.The average chain length and degree of polymerization of the rice starch granules increase with the increase of amylose content.The amounts of short chains of＂younuo 3＂were more than the long chains,which were almost the same with＂hua you xiang zhan＂rice starches.Results of texture porfile analysis indicated that the hardness,gumminess and chewiness of rice starch gels increase and the cohesiveness derease with the increase of amylose content.In addition,the transparency of rice starches continuously decreased.