Abstract
In this paper, we report the discovery of a relatively low-amylose sweetpotato starch. The chain-length distributions of debranched starches from 29 kinds of breeding lines of sweetpotato used in soups, croquettes and juices were examined. Among the 29 varieties, the starch from Kyukei 89376-12 had the smallest amylose fraction (11.7%), which was half that (21.6%) of a commercial sweetpotato starch. The apparent amylose content of the sweetpotato starch was estimated to be 11.3% and 10.9 by the blue-value method and the dual-wavelength method, respectively. The low-amylose starch showed relatively high maximum viscosity and remarkable breakdown similar to waxy corn starch, but the viscosity increase on cooling was similar to that of the commercial sweetpotato starch.
