Effect of Pressure (Crust Formation) on Bread Crumb Grain Development

ABSTRACT Previous work showed that the critical changes in crumb grain occurred during the early stages of baking. Oven spring and crust formation also occurred during this time. To determine whether the stress caused as a result of expansion during oven spring was related to the deterioration of crumb grain, doughs were baked at different heating rates to produce different expansion rates in an electrical resistance oven (ERO). The heating rate did not affect crumb grain, thus showing that the stress developed during oven spring are not related to changes in crumb grain. Therefore, two flours were selected that produced bread of different crumb grains when baked conventionally. However, when the two flours were baked in the ERO they gave similar (and fine) crumb grains. The ERO produces bread with no crust. This suggests that pressure in the dough resulting from crust formation during baking is one factor that affects the crumb grain of bread. Adding weight to the surface of the loaf to simulate crust formation caused the grain to change from good to poor as the weight was increased. Results from subsequent ERO baking studies suggest that the temperature range over which the gas cell walls of a wheat flour dough are most susceptible to coalescing is 60–70°C.