ICAR Research Data Repository for Knowledge Management

Freshly prepared sweet potato (SP) starch was separated quantitatively into amylose and amylopectin by a concanavalin A precipitation method. Amylose was further fractionated into two subfractions containing essentially linear (Am) and moderately branched (Ax) molecules, by hot-butanol extraction. The mole-
cular weight determined by GPC of Am was 3 x 106 Da, the values for Ap and Ax were 1.5x lo7 and 5 x 1O6 Da, respectively. The Beta-amylolysis limit values were 57,
70 and 92%, respectively, for Ap, Ax and Am. The native, as well as the derived Beta-limit dextrins of Ap and Ax, were debranched with isoamylase and their unit -
chain lengths, measured by GPC and SE-HPLC methods, showed Ap (CL, 21.0)to have a trimodal distribution of unit chains with m values of 52, 37 and 20, -whereas Ax had tetramodal unit chains with DP values of 40, 30, 21 and 9. Am
was more or less a linear molecule. In vitro SP starch was more digestible than legume and cereal starches.