Physicochemical properties of sweetpotato starch

Sweetpotato starch is high-yielding, but has limited development and uses. In this study, physicochemical properties of sweetpotato starch from 11 representative genotypes with diverse geographic origins in China were characterized and showed wide variations. Apparent amylose contents measured by iodine binding ranged from 23.3 to 26.5%, by gel permeation chromatography after debranching from 17.5 to 23.9%, and true amylose content by concanavalin A binding from 15.9 to 22.5%. In vitro digestibility varied from 29.5 to 41.2%. Swelling power and water solubility index were highly correlated (r2 = 0.88). Gelatinization peak temperature and enthalpy ranged from 75.4 to 79.7°C, and 7.6 to 13.6 J/g, respectively. Pasting peak and cold paste viscosities varied from 268 to 469 RVU, and 170 to 284 RVU. Amylose contents were highly correlated to digestibility, pasting, and thermal parameters.