Cereal Chem 47:492 - 500.  |  VIEW ARTICLE
Inactivation of Cereal Alpha-Amylase by Brief Acidification: The Pasting Strength of Wheat Flour.

P. Meredith. Copyright 1970 by the American Association of Cereal Chemists, Inc. 

Acidification of a wheat flour slurry to pH 2.5 or below irreversibly inactivates flour alpha-amylase. Inactivation is complete in only a few minutes at room temperature. Flour beta-amylase is largely destroyed under the same conditions. A neutralized inactivated slurry is suitable for most thickening purposes but not for bread-baking. The acid-inactivation process may be incorporated in several analytical procedures. Inactivated flours vary in pasting strength measured by amylograph and in susceptibility to alpha-amylase attack. Flour alpha-amylase has survived storage for 60 years at low temperature and for 10 years at room temperature.