COLLABORATIVE TRIAL ON THE DETERMINATION OF BETA-GLUCANASE IN MALT BY VISCOMETRIC AND DYE-LABELLED METHODS

The results of a collaborative trial to compare a dye‐labelled beta‐glucan method with that of a viscometric procedure, for estimating the beta‐glucanase content of malt, have demonstrated that overall the precisions of both methods are similar. There has been an improvement in the precision of the viscometric method (which is not a Recommended Method) compared with values obtained in previous trials. The Institute of Brewing Analysis Committee judged that the results obtained by the dye‐labelled beta‐glucan method were not sufficiently precise to permit adoption as a Recommended Method. However, since this procedure has advantages of speed and ease of operation, it is suggested as an alternative method to that relying on viscometry. It is envisaged that a further collaborative trial will be carried out when sufficient experience of the new method has been obtained. The repeatability (r95) and reproducibility (R95) values found were 0.190 m and 0.327 m over the concentration (m,U/kg) range 92–266 U/kg for the dye‐labelled method, and 0.173 m and (91.4 + 0.0717 m) over the concentration (m,IRV) range 233–701 IRV units for the viscometric method.