Cereal Chem 59:449 - 453.  |  VIEW ARTICLE
Functional (Bread-Making) Properties of Wheat Protein Fractions Obtained by Ultracentrifugation.

K. F. Finney, B. L. Jones, and M. D. Shogren. Copyright 1982 by the American Association of Cereal Chemists, Inc. 

Good-quality (RBS-76) and poor-quality (76-412) hard winter wheat flours were fractionated into crude gluten and starch plus water-soluble fractions. Gluten proteins, solubilized in 0.0045-0.005N lactic acid, were sedimented by ultracentrifugation into a pellet (high molecular weight, relatively insoluble glutenins), a gel (low molecular weight, relatively soluble glutenins), a viscous layer (high molecular weight, soluble gliadins), and a supernatant (low molecular weight, soluble gliadins). The corresponding gel and viscous layer plus supernatant fractions of the good- and poor-quality flours were interchanged singly in reconstituted flours containing the starch plus water-soluble fraction and baked into bread (10 g of flour). The gel glutenin proteins of the acid-soluble gluten proteins controlled mixing requirement and baking absorption, and the viscous layer and supernatant gliadin proteins controlled loaf volume and crumb grain. Sedimentation rates and physical properties of the different protein fractions varied greatly within a quality level, and the sedimentation rate of a given protein fraction varied materially between the two quality levels. When progressing from the polyacrylamide gel electrophoresis patterns of the supernatant to the gel protein fractions, densities of the rapidly moving bands (small proteins) decreased, and number and densities of the slowly moving bands (large proteins) increased.