Characterization of starch cooked in alkali by aqueous high-performance size-exclusion chromatography.

Abstract

Commercial corn starches with different amylose-amylopectin (AMYAMP) ratios were characterized using aqueous high-performance sizeexclusion chromatography (HPLC-SEC). Starch (0.5%) was boiled in water for 10 min, autoclaved for 10 min, sonicated for 20 sec, and centrifuged for 10 min. Molecularly dispersed starch in the supernatant was separated into AMP and AMY using water as the mobile phase. AMP molecules have a wider range of hydrodynamic volumes and apparent molecular weights than do AMY molecules. Boiled and autoclaved starch was not molecularly dispersed in water. After sonication treatment, this cooked starch was molecularly dispersed in water without depolymerization; however, complete molecular dispersion was not achieved. Starch cooked