Mathematical modeling of bread baking process

Baking of bread involves temperature, moisture content and volume changes that are strongly coupled. Previous work usually treated these processes separately or semi-empirically, without adequate accounting for the interaction. A model is developed considering heat and moisture transport that is fully coupled with large volume change. Viscoelastic material property is used and is a function of temperature. The model is applied to a conventional baking process and solved using a finite element method. Results from modeling agree with the experimental observations in terms of temperature, moisture, volume changes and surface browning. The model shows that higher than normal baking temperature reduces the baked bread volume. Microwave baking tends to heat the bread from the inside. Therefore, microwave baking, without other special treatment, creates no firm crust and collapsed dough. Sensitivity analyses have been performed for several material properties due to inaccurate or unavailable data for the model. Larger water activity, capillary diffusivity and smaller gas intrinsic permeability tend to over-predict the volume expansion and moisture loss.