EFFECT OF PRESSURE (CRUST FORMATION) ON BREAD CRUMB GRAIN DEVELOPMENT

Previous work showed that the critical changes in crumb grain occurred during the early stages of baking. Oven spring and crust formation al so occurred during this time. To determine whether the stress caused a s a result of expansion during oven spring was related to the deterior ation of crumb grain, doughs were baked at different heating rates to produce different expansion rates in an electrical resistance oven (ER O). The heating rate did not affect crumb grain, thus showing that the stress developed during oven spring are not related to changes in cru mb grain. Therefore, two flours were selected that produced bread of d ifferent crumb grains when baked conventionally. However, when the two flours were baked in the ERO they gave similar (and fine) crumb grain s. The ERO produces bread with no crust. This suggests that pressure i n the dough resulting from crust formation during baking is one factor that affects the crumb grain of bread. Adding weight to the surface o f 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 i s 60-70 degrees C.