Cereal Chem 66:144-148   |  VIEW ARTICLE

Effects of Neutral Salts of the Lyotropic Series on the Physical Dough Properties of a Canadian Red Spring Wheat Flour.

K. R. Preston. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

The effects of increasing concentrations of simple sodium salts of the lyotropic series (Cl-, Br-, ClO4-, I-, SCN-) on the farinograph, extensigraph, and alveograph properties of a Canadian red spring wheat flour were investigated. Additions of low levels of salt (0.05-0.10M) increased dough strength properties compared to results obtained with pure water. These effects were more pronouced in the presence of the more chaotropic anions, SCN- and I-. At higher concentrations (0.5-1.0M), the presence of chaotropic anions reduced dough strength properties and increased farinograph water absorption, whereas nonchaotropic anions (Cl-, Br-) increased dough strength properties and had little effect upon absorption. Increasing the concentration of chaotropic anions decreased dough extensibility whereas nonchaotropic anions increased dough extensibility. The general dough-strengthening effect at low salt concentrations compared to water can be attributed mainly to stronger interprotein interactions that result from electrostatic shielding of charged amino acids on the surface of the gluten proteins. The much larger effect of the chaotropic anions may be related to their ability to induce conformational changes in the gluten proteins that could further enhance interprotein interactions. At higher salt concentrations, the reduction in dough strength properties by chaotropic anions and the increase in dough strength properties by nonchaotropic anions can be attributed to their effects upon water structure that alter interprotein hydrophobic interactions.