EFFECT OF THE QUANTITY OF WHEAT-FLOUR PROTEIN ON BREAD LOAF VOLUME

The effect of flour protein content on dough expansion and rate of CO2 loss from doughs during baking and extended proofing were studied. When baked in a conventional oven, the doughs containing more protein expanded at a faster rate than those containing less protein. Profiles of CO2 loss from doughs during baking were not significantly affected by flour protein contents above 8.5%. When proofed for an extended period, the doughs containing more protein expanded at a faster rate and, more importantly, continued to expand longer than the doughs containing less protein. The difference in dough expansion rate might be attributed to the effect of flour protein on dough extensibility. Calculation of the difference in thickness of gas cell walls between doughs containing 8.5 and 11.5% protein suggests that the extent of dough expansion is mainly determined by how thin the gas cell walls can be stretched before reaching their expansion limit.