Effect of fat level, mixing pressure and temperature on dough expansion capacity during proving

In this work the effect of fat content on dough aeration during proving was investigated using, dynamic dough density measurements. Doughs of three different fat levels (0%, 0.04% and 0.2% flour basis) were mixed under various pressures using a Tweedy mixer and proved at five different temperatures (30, 35, 40, 45 and 50 degrees C) in the dynamic dough density system. The dough expansion capacity and the time of the gas loss of each dough sample were measured and related to fat level, mixing pressure and proving temperature. The time of gas loss decreased with increasing proving temperature for all fat levels, as expected due to increasing yeast activity and reduced carbon dioxide solubility. The final gas capacity of dough is affected by the mixing pressure and the temperature. Fat content had no significant effect on the time of the loss of gas retention or the dough's final expansion capacity. However, fat affected the pattern of gas loss towards the end of proving; thus in doughs with fat, the gas loss rate occurred smoothly and gradually, in contrast to the doughs with no fat that exhibited sudden gas loss. The findings demonstrated that the dynamic dough density method is a sensitive, straightforward technique for the investigation of factors affecting gas retention in bread doughs. (c) 2007 Elsevier Ltd. All rights reserved.