Effect of Acid-Soluble Wheat Protein and Improvement of the Sponge and Dough Method on Bread Quality Using Domestic Noodle Flour

Abstract

　In this study, we used acid-soluble wheat protein (ASP), which is mainly composed of gliadin, to improve the sponge and dough method. We were able to use domestic noodle flour, hitherto considered unsuitable for baking, and obtain a bread quality comparable to that made with imported strong wheat flour. The loaf bread volume and specific volume were investigated, and the microstructure of the gas cells in the bread crumb was observed. Further analysis was conducted to determine the degree of starch gelatinization, and bread crumb rheological properties such as firmness and cohesiveness changed over time. The results showed that the volume of noodle wheat flour bread increased with ASP addition. Furthermore, to enhance the dough gluten strength of the noodle wheat flour, the following steps were conducted: salt, which is usually added at the dough mixing stage, was added to the sponge dough, and the amounts of oxidizing agent and compressed yeast were increased. This led to a substantial increase in the bread volume and specific volume. Microstructure observation showed that the gas cell shape in the noodle wheat flour bread was similar to that of the control, which used wheat flour for bread. It was also confirmed that changes over time in rheological properties were suppressed, and that overall bread quality approached that of the control.