Cereal Chem 67:150-161   |  VIEW ARTICLE

Use of Sonication and Size-Exclusion High-Performance Liquid Chromatography in the Study of Wheat Flour Proteins. I. Dissolution of Total Proteins in the Absence of Reducing Agents.

N. K. Singh, G. R. Donovan, I. L. Batey, and F. MacRitchie. Copyright 1990 by the American Association of Cereal Chemists, Inc. 

Total proteins from a very strong wheat flour, Mexico 8156, were almost completely extracted without chemical reduction of disulfide bonds by applying mechanical shear with an ultrasonic probe in 2% sodium dodecyl sulfate solution at pH 6.9. Proteins from a very weak flour, Israel M68, were even easier to solubilize using this procedure. The increased solubility of flour proteins by sonication, compared with simple stirring, was similar to that achieved by mixing flour dough in a mixograph. However, sonication is more efficient, and hence it required much less time (30 sec) to achieve complete extraction of proteins. Furthermore, a very small quantity of flour sample, equivalent to half an endosperm (11 mg), is required for the study of wheat seed proteins using sonication in combination with size-exclusion high-performance liquid chromatography. By this method, the total unreduced flour proteins were fractionated into three distinct peaks of decreasing size range, representing mainly glutenin, gliadin, and albumin-globulin, respectively.