Cereal Chem 57:397 - 402.  |  VIEW ARTICLE
Hydrolysis of Large and Small Starch Granules from Normal and Waxy Barley Cultivars by Alpha-Amylases from Barley Malt.

A. W. MacGregor and D. L. Ballance. Copyright 1980 by the American Association of Cereal Chemists, Inc. 

Alpha-amylase I, the minor alpha-amylase component in malted barley, was more efficient than the major component, alpha-amylase II, in solubilizing the four types of starch granules studied. Large starch granules from normal barley were particularly resistant to hydrolysis by alpha-amylase II. No difference was detected by scanning electron microscopy between the action patterns of the two alpha-amylases on the same starch granules. No characteristic pinholes were observed in degraded small starch granules of either normal or waxy barley, both of which were hydrolyzed by surface erosion. Large degraded granules from normal barley contained many pinholes and appeared to be hydrolyzed from the inside out. Large granules from waxy barley appeared to be degraded by a combination of surface erosion and internal digestion via pinholes from the granule surface.