Cereal Chem 43:675 - 681. | VIEW
A Rapid Procedure for Alpha-Amylase Determination in Malt.
D. G. Medcalf, E. E. Tombetta, O. J. Banasik, and K. A. Gilles. Copyright 1966 by the American Association of Cereal Chemists, Inc.
The falling number procedure, developed by Hagberg for the determination of alpha-amylase activity in flour, has been adapted to the direct determination of alpha-amylase activity in malt. Dry malt or malt extract was mixed with a standard unmodified starch and the FNV determined. A straight line relationship was observed between FNV's and 20 degree Units of alpha-amylase activity (standard American Society of Brewing Chemists method) when the range of FNV's was not great. With a wide range of FNV's the relationship was curvilinear and a straight line was obtained by plotting on semilog paper. Both linear and semilog standard curves were made comparing alpha-amylase units to FNV's for dry malt and malt extract. The regression equations for these curves were used to convert FNV's to alpha-amylase units for 60 samples of dry malt and malt extract having a wide range of amylase activity. Correlations between alpha-amylase units determined directly by the standard method and values obtained with either the linear or nonlinear regression equations were quite high. However, the relationships were much more linear for values calculated with the nonlinear regression equations. The falling number procedure is simple and rapid, requires no special reagents, and has the advantage of being applicable to both dry malt and malt extract.