Water loss and crust formation during bread baking, Part II: Technological insights from a sensitivity analysis of a numerical model of baking

Abstract

ABSTRACTA 1D baking model was previously developed to improve the understanding of transport phenomena and bubble formation inside dough. Using this model, the present study focused on crust setting and its particular behavior. Simulation was used to study the influence of various parameters that govern crust setting and its characteristics such as thickness and porosity. On the basis of a literature review, the crust was defined as the “dry zone,” a region where the water content represents less than 0.60 kg/kg of dry matter. The mechanisms responsible for total water loss and crust setting were proposed in paper I and validated for multiple operating conditions: water loss is essentially driven by heat transport and to a lesser extent by the mechanism of water transport by evaporation–condensation–diffusion. In the present study, a sensitivity analysis of parameters of different driving mechanisms was undertaken through which it was possible to establish a hierarchy of the key parameters from a technological point of view. Overall heat transfer coefficient at the top of the loaf and thermal conductivity, or more generally the ratio between top and bottom heat fluxes, were ranked as the main parameters affecting crust setting and the water loss, thus suggesting a possible control of the process through the parameters evaluated.