ENZYMATIC DETERMINATION OF 1,3:1,4-β-GLUCANS IN BARLEY GRAIN AND OTHER CEREALS†

Abstract
A direct and specific enzymatic method is described for the determination of 1,3:1,4-β-glucans in barley grain and other cereals. In the procedure, purified, amylase-free, bacterial 1,3:1,4-β-glucan hydrolase is used to depolymerize the 1,3:1,4-β-glucan in autoclaved and ethanol-extracted flour prepared from whole grain. The liberated oligoglucosides are extracted with 80% (vol/vol) ethanol and, following acid hydrolysis, measured by the glucose oxidase method. The method can be used to measure total β-glucan and β-glucan in 65°C water-soluble and water-insoluble fractions of cereal grains. The procedure has been applied to barley grains allowed to develop under controlled environmental conditions and to a series of barleys of different geographical origins. The results for Canadian cultivars are compared with estimates based on viscometric data for the same samples. The 1,3:1,4-β-glucan content of a number of other cereals has also been measured.