Cereal Chem 55:1038 - 1049. | VIEW
ARTICLE
Extraction of High-Viscosity Gums from Oats.
P. J. Wood, I. R. Siddiqui, and D. Paton. Copyright 1978 by the American Association of Cereal Chemists, Inc.
Gum extracted by alkali from oats (Avena sativa L.) contained 70-87% beta-glucan. Flour particle size, and temperature, PH, and ionic strength of the extraction media, affected beta-glucan yields and its distribution between three consecutive extracts. Oat flour contained significant endo beta-1,3-glucanase, endo beta-1,4- glucanase, and mixed linkage endo beta-1,3-1,4-glucanase activities, which survived the alkaline extraction procedure. Enzyme deactivation of flour slightly decreased the yield of beta-glucan, but increased the viscosity of each extract. Viscosities considerably greater than previously reported for cereal beta-glucan, and greater than for many industrially important gums, have been obtained. High-viscosity samples had a high limiting viscosity number (17-18 dl/g) in both dimethylsulfoxide and 7M urea. Two cultivars of barley (Hordeum vulgare L.) contained somewhat less beta-glucan of lower viscosity than did most oat cultivars tested.