A SIMPLE-MODEL TO PREDICT MASS TRANSFERS IN DEHYDRATION BY OSMOSIS

The curves of dehydration by osmosis of 1 cm(3) apple cubes have been simulated assuming the existence of two diffusional species. The diffu sivity value of the two species, water and sucrose, was obtained by us ing a numerical method of non-linear regression analysis. The influenc e of the solution conditions (temperature and sucrose concentration) o n the absorption rate was evaluated. Two sets of experiments were carr ied out: experiments at 70 degrees Brix and different solution tempera tures (30, 40, 50, 60 and 70 degrees C) on the one hand, and experimen ts at 50 degrees C and different solution concentrations (30, 50 and 7 0 degrees Brix) on the other. The proposed diffusive model is able to explain 98% of the total variance. This model is also applicable to th e simulation of dehydration by osmosis for other food products.