DYNA

The aim of this study was to evaluate the influence of sample thickness (2, 3 and 4 mm) on the drying kinetics, water activity (a_w) and color (DE) of papaya puree slices processed through Refractance Window^TM technology (RW^TM). Additionally, the water diffusion coefficient (D_eff) was evaluated taking into account the shrinkage effect. The experimental values of moisture were fitted using Newton's and Midilli’s models. The results showed that the lower the thickness, the faster the drying, the lower the values of a_w and the higher the DE. The samples reached 0.0652, 0.1132 and 0.2624 g water/ g dry solid in 60 min for 2, 3 and 4 mm slices, respectively. Midilli's model was the most appropriate to predict the experimental curves of papaya drying through RW^TM. D_eff decreased at a lower thickness and its order of magnitude was of 10^-10 m²/s.