Cereal Chem 46:93 - 102.  |  VIEW ARTICLE
Functional (Breadmaking) and Biochemical Properties of Wheat Flour Components. I. Solubilizing Gluten and Flour Protein.

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

Gluten proteins, after solubilization in 0.005N lactic acid, were fractionated by precipitation at various pH levels with 0.1N sodium carbonate. In general, as pH increased for a given fraction, glutenins decreased and gliadins increased. The pH 6.1-soluble protein contained little or no glutenins but high concentrations of gliadins. The decrease in glutenins and increase in gliadins, as pH increased, were accompanied by a consistently large decrease in mixing time and baking absorption and an increase in oxidation requirement. Also, loaf volume of a protein fraction increased with higher pH values. The ratio of gliadin to glutenin in the pH 6.1-insoluble fraction was more nearly optimum for loaf volume than that in any of the other fractions or the crude gluten.Protein in wheat flour also was fractionated by water-solubilizing techniques. Extracted protein increased from 6.5% for one extraction to 37.6% of total flour protein for eight consecutive water extractions. The ratio of gliadins to other proteins increased markedly with each consecutive water extraction. Water-insoluble protein and starch fractions each contained the spectrum of proteins including glutenins, gliadins, and the rapidly moving bands. Evidence of protein interaction was obtained when the water-soluble protein and water-insoluble protein fractions were reconstituted and baked into bread.A dough moulder and other breadmaking equipment for processing 10 g. of flour are described.