S. Hagberg. Copyright 1960 by the American Association of Cereal Chemists, Inc.
A simple and rapid method for determination of amylase activity of flour and pulverized grain is described. The test may be completed in one or two minutes, depending on the amount of alpha-amylase present. The principle of the method depends on heating a flour-water suspension of 5 g. flour in 25 ml. water very rapidly to determine the time required to gelatinize and, subsequently, to liquefy the flour suspension. For practical purposes the "liquefaction time" is usually sufficient for evaluating the diastatic properties. However, from the "liquefaction time" and the "gelatinization time," both of which may be determined in the same test, the "diastatic number" may be computed. The "diastatic numbers" for different flours are related linearly to the alpha-amylase activity over a broad range.