DETERMINATION OF β‐GLUCAN IN WORT AND BEER BY ITS BINDING WITH CALCOFLUOR, USING A FLUORIMETRIC FLOW‐INJECTION‐ANALYSIS (FIA) METHOD

Abstract

The FIA‐fluorimetric methods for the determination of β‐glucan in worts and beers have been investigated, modified and improved. Fluorescence is excited by using a mercury lamp and a 338 nm band‐pass excitation filter, and detected using a 425 nm long‐pass emission filter. It has been found that an increase of the ionic strength of the eluent, up to a maxium of 1% Sodium Chloride, increases the range of β‐glucan molecular weights effectively bound by Calcofluor. The influence of the low molecular weight components of wort and beer: dextrins, aminoacids, etc, has been studied and found that their effect is negligible. The interference of wort and beer colour on the measurement of β‐glucan has been quantified and several approaches are given to overcome it. Thirty‐six European beers have been analyzed for β‐glucan content. The possible detection of the addition of exogenous β‐glucanases to wort and beer is discussed. 1989 The Institute of Brewing & Distilling