MODIFIED PROCEDURE FOR THE DETERMINATION OF DIASTATIC ACTIVITY AND α-AMYLASE ACTIVITY

Diastatic activity (Lintner value) and α-amylase activity can be determined by the same colorimetric measurements of reducing sugars formed by the action of malt extract on a starch substrate. For the determination of α-amylase activity, the β-amylase is differentially inactivated by a phenyl mercuric salt before diastasis. Measurement of reducing sugars produced is based on their reaction with 3,5-dinitro-salicylic acid. Total amylase and α-amylase activities may be recorded in the same units, or they may be converted to Lintner or SKB standard units with which they are closely correlated. There is considerable reduction in operating time and the methods are applicable in plant breeding projects or in quality control.