Osmo-convective dehydration kinetics of jackfruit (Artocarpus heterophyllus)

Osmotic dehydration is a process in which partial water is removed by immersion of water containing cellular solid in a concentrated aqueous solution of high osmotic media for a specific time and temperature. preliminary trials were planned for finalizing the concentration of osmolyte (salt solution: 5%, 10%, 15% and 20%). the osmotically pre-treated samples were dried at 50 °c which were examined using sensory parameters. on the basis of sensory parameters, 15% salt solution concentration was considered best. the osmotically pre-treated jackfruit samples of 15% salt solution were convectively dehydrated in a tray dryer at air temperatures of 50, 60 and 70 °c at constant velocity of 1.5 m/s air flow in perforated trays. results indicated that drying took place in falling rate period. the sample dried at 60 °c was found better in color as compared to samples at 50 and 70 °c. mathematical models were fitted to the experimental data and the performance of these models was evaluated by comparing the coefficient of determination (r^2), root mean square error (rmse), reduced chi-square (v^2), percent mean relative deviation modulus (e%) between observed and predicted moisture ratio. the best model was chosen as one with the highest coefficient of correlation (r^2); and the least v^2, rmse and mean relative deviation modulus (e). wang and singh model, having v^2 and rmse value (at 60 °c) of 0.00027 and 0.01655 respectively gave the best results for describing the drying behavior of jackfruit samples.