New Sweetpotato Lines have High Amylose and Resistant Starch Contents

Abstract

The sweetpotato is an important starch crop and a health-promoting food, owing to its richness in functional components. New sweetpotato lines (HA lines) with high amylose and high resistant starch (RS) contents are developed by cross-breeding, and the authors evaluate the root and starch properties and the influence of heat-treatment on the RS contents of these HA lines. The HA lines are found to have comparable root weights; much lower starch contents; more than 28% higher (45–59%) amylose contents; much lower viscosities, gelatinization temperatures, and gelatinization enthalpy changes; a higher proportion of both amylose and short chains (DP 6–11) fractions in the unit chain distribution of the debranched starches; and higher RS contents in gelatinized starches, raw, and heat-treated roots than those of the ordinary varieties. These results present useful information for food industries and breeders of sweetpotato.