Drying characteristics of walnut (Juglans regia L.) during convection drying

Drying characteristics of walnut were determined experimentally as a function of temperature, air velocity and variety (Serr, Pedro, Z67, K82). Four different drying models were fitted to the experimental data to select a suitable mathematical form of the drying curve. Experiments were performed at air temperatures of 32 and 43 degrees C and two air velocities of 1 and 3 m s(-1) at each temperature. Of the drying models tested, the Page model was selected as the best mathematical model based on the values of R-2, chi(2) and RMSE. Drying time and Page model constants were significantly dependent on the variables Studied. Correlations of the Page model constant, k and m the effective moisture diffusivity of walnuts and the drying time with the variables were determined. The effective moisture diffusivity of walnuts varied From 3.54 x 10(-7) to 9.92 x 10(-7) m(2) s(-1).