Abstract
A mathematical model based on Fick's second law was developed to predict the unidirectional moisture transfer in multidomain food products under realistic conditions with non perfect contact between components and variable storage temperature. Effective moisture difusivity dependence on moisture content and temperature was determined using independent moisture sorption experiments in a controlled atmosphere microbalance and in a diffusion cell. Local moisture distribution profiles were measured for several storage times in a food system constituted of a sponge cake and an agar gel separated by an air gap. A good fit between experimental and predicted values was observed for varying air gap sizes and varying storage temperatures (5, 20 and 30 degrees C). Temperature abuse during storage of a multidomain food product increased moisture movement, but the presence of a thin air gap between components increased the ability of a multidomain food product to withstand temperature fluctuations.