食用淀粉颗粒特性分析及掺假检测研究

Study on Particle Characteristics and Adulteration Detection of Edible Starches

以常见的19种食用淀粉为原料,对其颗粒结构、基本特性以及掺假检测方法进行了研究。由淀粉的扫描电镜图可知,19种淀粉分为5类,分别为棒形(莲藕和芡实淀粉)、扁平形(绿豆、小麦、莲子、山药和芭蕉芋淀粉)、球形或半球形(杏仁、薏米、红薯和木瓜淀粉)、不规则多面体形(葛根、魔芋、木薯、首乌、玉米、茯苓和百合淀粉)和卵形(马铃薯淀粉),通过淀粉颗粒形貌的不同可以为淀粉掺假鉴定定性分析提供参考依据。由淀粉的粒度分布可知,不同来源的淀粉的颗粒大小也相差很大,其中芭蕉芋淀粉、山药淀粉、莲藕淀粉、马铃薯淀粉和芡实淀粉的小颗粒所占的体积分数均小于1%,杏仁淀粉、茯苓淀粉、葛根淀粉、木瓜淀粉和莲子淀粉在测定粒度分布时没有检测到大颗粒(>30μm)。通过粒度分布法和快速黏度分析法分别对掺假淀粉做了检测分析,结果显示这两种方法都能够对特定的掺假玉米淀粉定量地检测出掺假比例。

In this paper,19 kinds of edible starches were used as raw materials,and the particle structure,basic features and adulteration detection methods of these starches were studied.According to the scanning electron micrographs,19 kinds of starches were roughly divided into five categories,namely rod shape(Lotus root and Semen euryales starch),flat shape(mung bean,wheat,lotus seed,yam,and C.edulis Ker starches),spherical or hemispherical shape(almond,coix seed,sweet potato,and papaya starches),irregular polyhedron shape(Kudzu root,konjac,cassava,Polygonum multiflorum Thunb.,corn,poriacocos,and lily starches)and oval shape(potato starch),respectively.The difference of the starch granule morphologycan provide a reference for qualitative analysis of starch adulteration identification.The results of particle size distribution measurement showed that it had significant difference in the particle size with different starch sources.Among these,the volume fraction of C.edulis Ker,yam,Lotus root and Semen euryales starch were less than 1%,and large particles(>30μm)can not be found in almond,poriacocos,Kudzuroo,papaya and lotus seed starch.Two methods of particle size distribution and rapid viscosity analysiswere used to analyze these starches,and the results showed that both the two methods were able to detect adulteration ratio of corn starch.