The mathematical modelling of the osmotic dehydration of shark fillets at different brine temperatures

The effect of brine temperature (20, 30, 40 and 50 degrees C) on the osmotic drying behaviour of shark slabs (10 x 5 x 1 cm) in saturated (100 degrees) brine was investigated. The parameters investigated were weight reduction, water loss, salt gain and water activity. Salt uptake and moisture data were analysed using various mathematical solutions based on Fick's Law of Diffusion and the effective diffusion coefficients were predicted after considering the process variables. The expressions presented by Azuara et al. (1992), based on the model presented by Crank (1975), were successfully used to predict the equilibrium point and to calculate diffusion coefficients at not only the initial stages of dehydration, but also at different times during the osmotic process.