MEASUREMENT OF (1 → 3)(1 → 4)-β-<scp>d</scp>-GLUCAN IN MALT, WORT AND BEER

Abstract

A method developed for the quantification of (1 → 3)(1 → 4)-β-d-glucan in barley flour has been modified to allow its use in the measurement of this component in malt, wort, beer and spent grain. For malt samples, free d-glucose was first removed with aqueous ethanol. Quantification of the polymer in wort and beer samples involved precipitation of the β-glucan with ammonium sulphate followed by washing with aqueous ethanol to remove free d-glucose. Spent grain was lyophilised and milled and then analysed by the method developed for malt. In all cases, the β-glucan was depolymerised with lichenase and the resultant β-gluco-oligosaccharides hydrolysed to d-glucose with β-d-glucosidase. The released d-glucose was then specifically determined using glucose oxidase-peroxidase reagent.