Modeling of Hot Air Drying Kinetics of Tofu

Hot air drying kinetics of tofu was investigated in a laboratory scale hot-air dryer at different temperature (40^oC, 50^oC and 60^oC) and with different size range of (1 cm x 1 cm x 1 cm, 1 cm x 1.5 cm x 1 cm, 1 cm x 2 cm x 1cm and 1 cm x 3 cm x 1cm). Results indicated that drying took place in the falling rate period. The relationship between surface area and moisture content is a second order relationship with positive correlation. Two mathematical models; the Page and the simple exponential model, were fitted to the experimental data, which described the drying kinetics of tofu. The performances of these models were evaluated by comparing the coefficient of determination and reduced chi-square between the observed and predicted moisture ratio. The best results for describing single layer drying of tofu were obtained through Page model.