A study of coupled heat and mass transfer in composite food products during convective drying

A two-dimensional liquid diffusion model was developed to predict the variation of transient moisture content and temperature distribution within model composite food products. Rectangular-shaped potato and apple slices were used to form the model composite samples for experimental tests. To verify the predictions of the theoretical model, a series of experiments were conducted on the model composite samples using a heat pump-assisted convective dryer. Effects of using different adhesives to hold the two slices forming the composite products, flipping of the products at selected intervals of time and variation of individual slice thickness were investigated both experimentally and numerically. Predictions of the numerical model are in good agreement with the experimental results.