diastase di·a·stase (dī'ə-stās', -stāz')
n.
An amylase or a mixture of amylases that converts starch to dextrin and maltose, is found in certain germinating grains such as malt, and is used to make soluble starches, to aid the digestion of starches, and to digest glycogen in histological sections.
any member of a class of enzymes that catalyze the hydrolysis (splitting of a compound by addition of a water molecule) of starch into smaller carbohydrate molecules such as maltose (a molecule composed of two glucose molecules). Two categories of amylases, denoted alpha and beta, differ in the way they attack the bonds of the starch molecules.