This method describes the fluorimetric determination of the β-glucan content of malt.
High molecular weight ß-glucan includes (1−3)(1−4)-β-D-glucan.
The β-glucan content of barley influences the modification processes, which occur during malting and consequently affects malt quality.
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.