Cereal Chem 42:275 - 287. | VIEW
Studies on Short- and Long-Mixing Flours. II. Relationship of Solubility and Electrophoretic Composition of Flour Proteins to Mixing Properties.
D. E. Smith and J. D. Mullen. Copyright 1965 by the American Association of Cereal Chemists, Inc.
Mixing properties of doughs prepared from salt-soluble, water-soluble, and protein-starch residue fractions of short- and long-mixing flours were determined with the farinograph. Fractions were recombined and interchanged to determine 1) the role of the fraction in dough-mixing properties and 2) the fraction responsible for mixing differences between the flours. The mixing results were interpreted in terms of protein composition as determined by moving boundary electrophoresis and -SH and S-S content. Salt- soluble fractions (albumins and globulins) had little effect upon mixing characteristics. Protein-starch residues (glutenins) had long-mixing requirements, whereas the addition of water-solubles (gliadins) markedly shortened the mixing requirements. Combinations of these two latter fractions in the ratios obtained during fractionation resulted in doughs similar to the original flours. Short-mixing flour contained more water-soluble protein initially and more was produced during mixing. Additives which decreased protein solubility markedly increased mixing requirements. Study of -SH and S-S content of fractions indicated that mixing properties were not controlled by the total amount of these functional groups. The mixing differences of these two flours appear to be determined by undefined characteristics of the protein- starch residues and the quantity and molecular-weight distribution of the water-solubles.