VIEW ARTICLE    DOI: 10.1094/ASBCJ-41-0161

Nonenzymic Method for Determination of β-Glucan in the Presence of Starch. John P. Madacsi, Frederick W. Parrish, and Earl J. Roberts, Southern Regional Research Center, Agricultural Research Service, U. S. Department of Agriculture, New Orleans, LA 70179. J. Am. Soc. Brew. Chem. 41:0161, 1983.

Current methods of analysis of β-glucans in cereal grains generally employ enzymes, but these methods are either laborious or imprecise. (β-Glucans are generally accompanied by starch in the aqueous extracts from cereals). Therefore, a nonenzymic method has been developed for β-glucan analysis, which depends on the quantitative precipitation of β-glucan with alkaline copper sulfate. The amount of β-glucan-copper complex is measured by a standard phenol-sulfuric acid procedure. Starchlike polysaccharides in amounts up to 250 times the amount of β-glucan do not interfere. Extraction of β-glucan from cereals with aqueous alkaline solutions can result in loss of up to 40% of the β-glucan. Such loss can be minimized by incorporation of sodium borohydride in the extraction medium.

Keywords: β-glucans, Cereals, Copper sulfate reagent, Phenol-sulfuric acid, Sodium borohydride, Starch