Publication no. C-2000-0417-02R |  VIEW ARTICLE

Effect of Extrusion Cooking on the Primary Structure and Water Solubility of beta-Glucans from Regular and Waxy Barley.

Jiang Gaosong (1) and Thava Vasanthan (1,2). (1) Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada. (2) Corresponding author. Phone: (780) 492 2898; Fax: (780) 492 8914; E-mail: <tvasanthan@afns.ualberta.ca> Cereal Chem. 77(3):396-400. Accepted February 29, 2000. Copyright 2000 American Association of Cereal Chemists, Inc.

Water-soluble beta-glucan from native and extrusion-cooked barley flours of two barley cultivars, Candle (a waxy starch barley) and Phoenix (a regular starch barley), was isolated and purified. The purity of beta-glucan samples was 85-93% (w/w, dry weight basis) for Candle and 77-86% (w/w, dry weight basis) for Phoenix. The water solubility of beta-glucan (at room temperature, 25°C) in the native and extruded flours (primary solubility) was different from that of the purified beta-glucan samples (secondary solubility). The solubility of beta-glucan in the native and extruded Candle flour was substantially higher than that of beta-glucan in Phoenix. For both cultivars, beta-glucan in the extruded flours had solubility (primary solubility) values higher than in their native counterparts. The solubility of beta-glucan in the purified beta-glucan samples differed depending on the barley cultivar and the extrusion conditions employed. The glycosidic linkage profiles of purified soluble beta-glucan from native and extruded barley flours were determined in order to understand the changes in the primary structure of beta-glucan and the effect of extrusion on the beta-glucan structure-solubility relationship.