Kinetics of Bubble Growth in Bread Dough and Crust Formation

Abstract

The final texture, aerated structure, and palatability of bread strongly depends on the creation of gas bubbles during the mixing process, the control of their growth in the dough matrix during subsequent breadmaking stages, and their retention until the dough matrix is set. Therefore, gas production and gas retention in the bread dough are crucial during the breadmaking process in order to make good-quality bread. The gas production in the dough is through CO2 generation by yeast or by chemical leavening agents during fermentation and release of water vapors from the dough matrix due to high temperature during baking. The retention of these gases is impaired by physical instability processes, particularly the coarsening of bubbles, that invariably occur during breadmaking. Noninvasive imaging techniques combined with image analysis methods can be used to quantitatively analyze dough and bread microstructure, the kinetics of bubble growth, and factors affecting the evolution of the cellular structure in the crumb and the crust. The speed at which structural transitions occur during baking presents significant challenges to understanding how such transitions affect bread quality. Therefore, various modeling techniques, both analytical and numerical, have been proposed to offer additional insights into the linkage between the structure of dough and that of bread. Continued improvements in quantitative image analysis techniques are expected to further our understanding of the internal structure of bread dough and its dynamics and their relationship to bread quality.