Determination of β-glucan content of cereals with an amperometric glucose electrode

A rapid method for determination of the soluble and total amount of beta-glucan was investigated. beta-Glucan was extracted from the samples with the modified extraction method and then incubated with lichenase and beta-glucosidase. The optimum incubation parameters were determined by using pure beta-glucan solutions as follows: lichenase concentration, 0.04 international units (IU) ml(-1); beta-glucosidase concentration, 0.125 IU ml(-1); reaction time, 20 min; reaction temperature, 50 degreesC; reaction acidity, pH 6. After enzymatic incubation, free D-glucose produced by the action of enzymes on soluble and total beta-glucans was measured with an amperometric glucose electrode. The linearity of the beta-glucan assay was determined as 8.0% (w/w) under the considered enzymatic reaction condition. In the last part of the study, soluble and total beta-glucan contents of certain samples were determined by both the improved method and the AOAC Official Method. A high correlation (R-2: 0.992) between the results of these two methods was observed.