STUDIES ON THE ENZYMATIC HYDROLYSIS OF SWEET POTATO STARCH

Abstract

Tropical crops, of which sweet potato is an important representative, constitute an underexploited resource of developing countries. This agricultural product can be used as food for both human and animal consumption and the starch is a source of industrial raw material. To utilize starch, the organisms must have enzymes that catalyze the hydrolysis of the (1?4) glycosidic bonds. Enzymes that are capable of catalyzing the hydrolysis of the ?-D-linkage are called amylases and are widely produced by plants, bacteria and animals. In this study, extracted sweet potato starch and sweet potato tubers have been used as models to investigate the action of alpha-amylase hydrolysis. In general, ?-amylase are endoglycosidases, attacking glucans somewhere away from the chain ends at an internal glycosidic bond and producing a rapid drop in the viscosity of the substrate. Alpha-amylase also produce varying types of oligosaccharides, characteristic of the particular ?-amylase. Amylase almost universally distributed throughout the animal, plant and microbial kingdoms. Amylase can convert starch into edible products, into products used in paper and pharmaceutical industry, or into other products having specific properties. Selected from 21 different sweet potato starches, six cultivars were chosen to study the effect of genetic variability on granule susceptibilities to alpha-amylase attack. The original samples of 21 starches were extracted from