Bubble Formation and Stabilization in Bread Dough

Abstract

The gas phase of bread, which makes up more than 70% of the final volume of a loaf, has a major influence on its textural and sensory attributes. Controlling the gas phase volume is a major challenge as during proving and early stages of baking gas must be captured within bread dough, only being released at the end of baking. The factors important in determining the gas cell structure are discussed, treating the system as a foam. These include (1) the formation of the initial foam structure during mixing, and (2) stabilization of the foam structure, including those factors governing bubble disproportionation and coalescence. There is particular focus on the role that thin films lining the bubbles may play in stabilizing the foam structure of a risen dough. Despite its potential importance, little is known about the surface properties or composition of the aqueous phase of doughs from which the films are thought to form. We summarize current understanding of the role surface properties may play in determining the aerated structure of dough, and hence the textural characteristics of bread as well as its implications for process engineering aspects of the mixing and proving stages of bread production.