Effective moisture diffusivity during hot air solar drying of tomato slices

Mathematical modelling and effective moisture diffusivity of tomato (Lycopersicon esculentum) was studied during hot air solar drying. An experimental solar dryer with a swivel collector was used for experiments. The collector followed the solar radiation using a precious sensor. Drying experiments were performed in a thin layer hot air drying at slice thicknesses of 3, 5 and 7 mm and air velocities of 0.5, 1 and 2 m/s. The experimental data were fitted to different mathematical moisture ratio models and the Page model was selected as the best model according to correlation coefficient R2, chi-square χ2 and root mean square error (RMSE) parameters. The maximum values of moisture diffusivity was 6.98 × 10-9 m2/s at air velocity of 2 m/s and slice thickness of 7 mm while the minimum value of the moisture diffusivity was 1.58 × 10-9 m2/s at air velocity of 0.5 m/s and slice thickness of 3 mm.