Tray dryers and their developed forms, tunnel dryers are equipments, which found many applications in food operation operations during dehydration of foods. All the drying characteristics of foods can be observed in these equipments. A typical drying procedure was applied with tray dryer to investigate properties of tray dryers, its advantages or disadvantages, drying kinetics of foods that are dried in tray dryers.
For these purposes, equilibrium moisture content, drying rate, mathematical and experimental drying time were calculated with some engineering formulas. Wet pepper was used as sample The result demonstrated that the most important parameters in drying of foods by tray dryer, which affect the time and the quality of food, are temperature and velocity of air, moisture content of food and surface area that is exposed to heated air.