STUDIES ON THE STRUCTURE OF PEA STARCHES .4. INTERMEDIATE MATERIAL OFWRINKLED PEA STARCH

Beta-Limit dextrins were isolated from wrinkled pea starch, fractionat ed into different sizes, and their molecular weight distribution analy sed by gel chromatography. A minor part of the dextrins had high molec ular weight and long chains typical for amylose. The major part of the dextrins had low molecular weight and possessed unit chains of the sa me types as was found in the amylopectin of smooth pea starch. However , the proportion of long chains was significantly higher. The hydrolys is of wrinkled pea starch with alpha-amylase was fast and reflected th e large content of amylose, whereas the hydrolysis of the beta-limit d extrin was slow. The intermediate dextrin products obtained from the l atter had similar molecular weights as those produced from other amylo pectins, which indicated that it was build up of clusters of branching s. Structure models that show the mode of interconnection of the clust ers in the intermediate material are suggested.