Study on Particle Characteristics and Adulteration Detection of Edible Starches

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 (> 30 μm) 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.