Effect of Chemical Modification, pH Change, and Freezing on the Rheological, Solubility, and Electrophoretic Pattern of Wheat Flour Proteins

摘要

In this study the effect of chemical modification and free/ing of dough on the characteristics of wheat proteins and the rheological properties of dough was investigated. A slight increase in the protein solubility and disappearance of protein bands in the range of 55 to 70 KDa was observed when samples were frozen for 6 to 8 weeks. Ascorbic acid decreased and cysteine and bisulfite increased solubility of wheat proteins. Dough stability increased as pH was raised above 6.5. Two protein bands in the range of 55 to 60 KDa appeared in ascorbic acid treated doughs and the intensity of bands of less than 6.5 KDa increased in cysteine or bisulfite treated doughs. Several protein bands in the range of 30, 50, and 90 KDa appeared when the pH was raised to 7.0 and above. The results of this study suggest that high- molecular-weight proteins of wheat flour have a major influence on the properties of dough and that these proteins are affected by chemical treatment, pH change, and freezing.