Mathematical modeling of drying kinetics of milky mushroom in a fluidized bed dryer

Drying kinetics of milky mushroom slices (10 mm) in a fluidized bed dryer was studied at air temperatures of 50, 55 and 60 degrees C. Drying of milky mushroom slices occurred in falling rate period. In order to select a suitable drying curve, eight thin layer-drying models were fitted to the experimental moisture ratio data. Among the mathematical models investigated, Wang and Singh model best described the drying behaviour of mushroom slices with high correlation coefficient (R 2) values. The effective moisture diffusivity (D-eff) of mushroom increased as the drying air temperature increased. The moisture diffusivity in milky mushroom was found to increase from 1.55 to 4.02 x 10(-9) m(2) s(-1) during the initial stage of drying, and from 8.76 to 16.5 x 10(-9) m(2) s(-1) during the later stage of drying. Drying at temperature of 60 degrees C required minimum activation energy to detach and move the water during the drying process.