This method describes the fluorimetric determination of high-molecular weight β-glucans in malt.
Malt intended for use in beer brewing or elsewhere in the food industry
The fluorochrome Calcofluor forms a complex with high molecular weight β-glucans (molecular weight greater than 5 kDa). Complex formation results in an increase in fluorescence; however, this fluorescence is extremely unstable due to photochemical degradation.
Through measurement in an automatic analysis system based on flow injection (flow-injection analysis, fig. 1), reproducible measurements for fluorescence and determination of β-glucan are possible. For barley analysis, it is necessary to use a short acid hydrolysis procedure to bring insoluble β-glucan into solution. The apparatus is calibrated using purified barley β-glucan standards.