Cereal Chem 65:326-333   |  VIEW ARTICLE

Multiple Alpha-Amylase Components in Germinated Cereal Grains Determined by Isoelectric Focusing and Chromatofocusing.

A. W. MacGregor, B. A. Marchylo, and J. E. Kruger. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

Isoelectric focusing showed that germinated barley (two- and six-rowed), wheat (hard red spring and amber durum), rye, and triticale contained multiple forms of alpha-amylase that could be divided into low- (less than pI 5.5) and high-pI (greater than pI 5.8) groups. Only low-pI alpha-amylase components were found in germinated oats, corn, millet, sorghum, and rice. Quantitative data on the proportions of high- and low-pI groups in barley, wheat, rye, and triticale were obtained by chromatofocusing. Barley contained the highest proportion (97.9%) of high-pI alpha-amylase and amber durum wheat the lowest (79.1%). In addition, chromatofocusing showed that germinated corn contained a group of alpha-amylase components having pI values between those of the high and low-pI groups. A comparison of the accurately measured alpha- amylase values from chromatofocusing with alpha-amylase component profiles obtained by isoelectric focusing revealed that determination of the relative proportions of alpha-amylase components on isoelectric focusing gels by visual inspection could be misleading. There was an immunochemical relationship among the low-pI alpha-amylase components of barley, wheat, rye, triticale, the major alpha-amylase components of millet, sorghum, and possibly oats, and a minor component in corn.