α-1,4-GLUCANS. PART XX. THE MOLECULAR STRUCTURE OF THE STARCHES FROM OATS AND MALTED OATS*

Starch was isolated from samples of oats and malted oats, and fractionated into amylose and amylopectin components. Analysis showed that malting caused a very limited decrease in the molecular size of the amylose, and a small but significant reduction in the exterior chain length of the amylopectin. These changes are very similar to those which occur when oat starch granules are subjected to limited α-amylolysis. It is suggested that α-amylase is the predominant enzyme involved in the changes which occur in cereal starches during malting.