A Quality Control Method for the Determination of Vicinal Diketones and Precursors in Fermenting Wort. H. Garza-Ulloa, E. González, A. M. Canales, and J. A. Sierra, Cerveceria Cuauhtémoc, S. A., Monterrey, N. L., México. J. Am. Soc. Brew. Chem. 40:0015, 1982.

A method is proposed for the determination of vicinal diketones (VDK) and precursors in fermenting wort. The method, which can be used for routine quality control analysis, is an improvement over the previously published ASBC method in that the conversion of precursors to VDK is done during the sweeping of the sample with oxygen at 75° C, thus eliminating an additional sample treatment step to convert precursors to VDK. The equipment used is easy to construct, low in cost, and permits the assembly of several apparatuses for simultaneous determinations. The proposed method possesses several advantages over other published methods, eg, fewer interferences, higher sensitivity, and complete conversion of precursors to VDK. More important the results obtained are very similar to those obtained by a gas chromatographic method.

Keywords: Diacetyl, Fermenting wort, Quality control, Spectrophotometric method, Total vicinal diketones