PARTIAL HYDROLYSIS OF GELATINIZED BARLEY AND WAXY BARLEY STARCHES BY ALPHA-AMYLASE

The hydrolysis of gelatinized commercial barley starch by Bacillus lic heniformis alpha-amylase began by rapid depolymerization of amylopecti n in two stages. The formation of low molecular weight hydrolysis prod ucts, as indicated by an increase in reducing power, was only observed when all the original high molecular weight amylopectin had degraded further. The hydrolysis of waxy barley starch followed a similar patte rn. Hydrolysis had a big influence on the microstructure of the starch dispersion: first the degradation of the amylopectin rich granule res idues ('ghosts') was observed, and later amylose aggregates were forme d.