Influence of drying conditions and mathematical models on the drying curves and the moisture diffusivity of mushrooms
1National Technical University of Athens, School of Mechanical Engineering, Laboratory of Thermal Processes, 9 Iroon Polytechniou Street, Zografou 15780 Athens, Greece
J Ther Eng 2015; 1(4): 236-244
Full Text PDF

Abstract

In the present research, experimental data from several studies about drying behavior of mushrooms have been selected and used to compare different drying methods and different mathematical thin layer drying models to simulate mushroom drying rates. The white button (Agaricus Bisporus), the oyster (Pleurotus Ostreatus) and the milky mushroom slices have been considered for drying in different dryers with different slice thicknesses, drying air temperatures (45 °C to 90 °C) and drying air velocities (0.2 m/s to 5 m/s). The entire drying process has taken place in the falling rate period, assuming that internal mass transfer occurred by diffusion in mushroom slices. Additionally, the effective moisture diffusivity was calculated by using the method of slopes. The diffusivity increases with drying air temperature. The study shows that the drying air temperature and the drying air velocity have an effect on the moisture removal from mushrooms and also on the drying time. Mathematical models have been proved to be useful for design and analysis of heat and mass transfer during drying processes. All the drying models considered in this study could adequately represent the thin layer drying behavior of mushrooms. Furthermore, as it is obvious, any type of mushrooms has its own most suitable model.