DETERMINATION OF THE DIASTATIC POWER OF MALT IN DEGREES LINTNER BY MEANS OF A FERRICYANIDE REAGENT

Abstract

It is proposed that the Official Method, of the American Society of Brewing Chemists, for the determination of the diastatic power of malt be modified to permit the use of the Blish and Sandstedt ferricyanide method for determining the reducing power of the digested starch solution. The proposed method involves the use of half the quantity of infusion, rather than twice the quantity of starch, for making diastases of malts with Lintner values of over 135° L. Both changes increase the speed of determination without loss of precision or accuracy. For routine purposes additional speed can be obtained by omitting the dilution of the infusion and by requiring a blank correction for the reducing power of the starch only.Experimental data show that under the conditions of the determination the ferricyanide method provides an accurate measure of the reducing power of the digested starch solution, and that the results obtained by the two methods, for 16 malts with diastatic powers covering the range from 72° to 185° L., agree to within 3%.