Characterization of Beer Polysaccharides by Enzymes and Gel Permeation Chromatography

Abstract

Analyses were made on beer polysaccharides eluting in the excluded volumes of different polyacrylamide-gel bead columns. The distribution of polysaccharides in certain molecular-weight ranges was obtained. An example is a comparison of the excluded volume contents of Bio-Gel® P-2 and P-4 columns, with minimum molecular weights of 1800 and 4000, respectively. The range between 1800 and 4000 is calculated by difference. Analyses of six American and one German beer showed similar distributions of molecular-weight ranges. The carbohydrate of the molecular-weight range of 1800 and greater could be partially decreased not only by amyloglucosidase but also by β-glucanase or pronase. Thus, there is residual β-glucan and protein-bound carbohydrate, in addition to dextrin. There was no significant difference in the amount of carbohydrate in the excluded volumes of P-10 and P-30 columns, showing that the contents of the former contain polysaccharide with a minimum molecular weight of 40,000. The action of amylases during malting and mashing should leave little dextrin of this molecular size; nevertheless, a considerable portion of this fraction is degradable by amyloglucosidase.

• Beer
• Gel permeation
• Polysaccharides