Influences of grinding on structures and properties of mung bean starch and quality of acetylated starch

Abstract

The aim of this study was to reveal the mechanism of preparing high quality modified starch by grinding. Modified starch and acetylated starch with low degree of substitution were prepared under grinding. The influences of grinding on structures and properties of mung bean starch and quality of acetylated starch were investigated. The influence mechanisms were analyzed using the theory of mechanochemistry and the models of starch granules and molecules. The results indicated that there were pores and umbilical points with loose structure in mung bean starch granules. During the grinding treatment, starch granules were constantly deformed like elastic balls, and starch molecules could keep moving and rearrange, resulting in changes in structures and properties of starch. It could be seen that grinding had a marked mechanochemical effect on starch granules. As a result, the reaction efficiency of the starch rose to 81.61% at 12 h of grinding, and other qualities (solubility and swelling power) were also improved.