FURTHER STUDIES ON THE STARCHES FROM BARLEY AND MALTED BARLEY: COMPARISON OF STARCHES FROM THE PROXMAL AND DISTAL HALVES OF THE GRAIN

Abstract

Starch was isolated from the proximal (adjacent to the embryo) and distal halves of grains of barley and malted barley of the same sample of cereal, significant differences being found in the iodine affinities and gelatinization temperatures of the resultant starch samples. The fine structures of the amylose and amylopectin components have been investigated. On dispersion and subsequent fractionation, differences were found in the β-amylolysis limit and molecular size of the amylose components from the barley starches. These differences might be related to the maturity of the starch. The properties of the amyloses from the malted barley samples were consistent with a general limited α-amylolytic attack on the barley amylose during malting. The barley amylopectins differed with regard to chainlength and β-amylolysis limit; the properties of the malted-barley amylopectins could be accounted for by limited β-amylolysis of this component during malting.