Publication no. C-1997-0618-04R |  VIEW ARTICLE

Molecular Weight Distribution and (1-3)(1-4)-beta-D-Glucan Content of Consecutive Extracts of Various Oat and Barley Cultivars (1).

Michael U. Beer (2), Peter J. Wood (2,3), and John Weisz (2). (1) Contribution 2413 of the Centre for Food and Animal Research, Agriculture and Agri-Food Canada, Ottawa. (2) Centre for Food and Animal Research, Agriculture and Agri-Food Canada, Ottawa, Ontario, K1A 0C6, Canada. (3) Corresponding author. E-mail: <WoodP@EM.AGR.CA> Cereal Chem. 74(4):476-480. Accepted March 11, 1997. Copyright 1997 Department of Agriculture and Agri-Food, Government of Canada.

The content and molecular weight (MW) of beta-glucan in extracts from a selection of oat and barley cultivars were compared using flow-injection analysis and high-performance size-exclusion chromatography. From 60 to 75% of the beta-glucan was extracted from oat and waxy barley by hot water (90°C) containing heat-stable alpha-amylase, whereas just 50-55% was extracted from nonwaxy barley. Consecutive extractions with hot water and dimethylsulfoxide (DMSO) extracted 65% (nonwaxy barley) or 75-80% (oat and waxy barley) of the total beta-glucan. An extraction with sodium hydroxide and sodium borohydride (NaOH/NaBH(4)) increased the percentage of beta-glucan extracted to 86-100% but decreased the MW. The MW of beta-glucan in the oat cultivars selected was significantly higher than those in the barley cultivars. The beta-glucan extracted from the nonwaxy barley cultivars showed significantly higher peak MW than that from the waxy barley cultivars.