Cereal Chem 46:126 - 135.  |  VIEW ARTICLE
Functional (Breadmaking) and Biochemical Properties of Wheat Flour Components. III. Characterization of Gluten Protein Fractions Obtained by Ultracentrifugation.

R. C. Hoseney, K. F. Finney, M. D. Shogren, and Y. Pomeranz. Copyright 1969 by the American Association of Cereal Chemists, Inc. 

The gluten protein fraction governed the quality factors of mixing time and loaf volume. Solubilization of the gluten in 0.005N lactic acid (pH 4.7) left an insoluble fraction consisting of 5 to 8% of the total flour protein. The insoluble fraction had no specific role in breadmaking. The pH 4.7-soluble gluten was fractionated by ultracentrifugation at 100,000 x g for 5 hr. Approximately 15% of the protein was recovered as centrifugate (100-5C) and 85% remained in the supernatant (100-5S). Starch-gel electrophoresis characterized the fractions as (a) proteins retained at the origin (centrifugate), and (b) proteins migrating into the starch gel (supernatant). The two fractions, when reconstituted and baked into bread, had loaf volumes and crumb grains equal to those of the original flour. The proteins migrating into the starch gel were responsible for loaf-volume potential when the two fractions from good- and poor-quality varieties were interchanged.