Morphology of some legume and tuber starches grafted with polyacrylonitrile

Abstract

Morphological aspects of three legumine and three tuber starches and their graft copolymers with polyacrylnitrile (PAN) prepared from granular and gelatinised states have been reported. Scanning electron microscopy revealed that grafting characteristics of legumine and tuber starches are quite different. In potato starch the hydrolysed S-g-PAN product showed that the grafting has occurred in the interior. In case of sweet potato starch a little grafting occurred on the surface of depression while normal grafting might have taken place in the interior through the depression. Little grafting seems to have occurred inside the tapioca starch granules. The grafting on legumine starches has mainly occurred on the surface of granules.