Cereal Chem 66:97-103   |  VIEW ARTICLE

Large-Scale Preparation and Properties of Oat Fractions Enriched in (1-3)(1-4)-Beta-D- Glucan.

P. J. Wood, J. Weisz, P. Fedec, and V. D. Burrows. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Large amounts (kilograms) of oat gum, the major component of which is (1-3)(1-4)-beta-D-glucan (beta- glucan) and oat bran were prepared for nutritional studies using pilot plant equipment. Bran fractions, containing from 10.9 to 16.6% beta-glucan and which were used to increase the yield of gum, were prepared by air-classification of hexane-defatted flour or of full-fat flour, and by simple sieving techniques. Defatted, air-classified bran after refluxing in ethanol to deactivate enzymes, was extracted with sodium carbonate at pH 10 to give oat gum containing 78% beta-glucan. This material was found to exhibit significantly lower viscosity than material prepared at the bench. Monitoring the pilot plant process showed that the major viscosity losses occurred during centrifuging. Oat gums were pseudoplastic in aqueous solution, but under conditions of high shear there was a permanent loss in viscosity. This was reflected in reduced molecular size as shown by high-performance gel chromatography, which also revealed bench- prepared oat gum to be of higher molecular weight than pilot plant gum. No difference in the major structural characteristics was detected between pilot plant material and bench material or betweeen beta- glucan derived from the inner and outer parts of the grain.