The present work was aimed to study the effect of pretreatments and drying temperatures on quality and drying characteristic of onion slices in tray dryer and to study the effect of drying air temperature (1st stage drying at 70, 80, 90ËšC and 2nd stage at 600C) on onion slices (2, 4, and 6mm) also examine size, pretreatments water blanching and 0.2, 0.4, 0.6 % Potassium Metabisulphite on the quality of dried onion. Result of study showed that the water blanched onion samples dried at 90ËšC (6mm size) took least time to get dry. Rehydration ratio was increased with increase in temperature. Potassium Metabisulphite blanched sample dried at 70ËšC were better in nutritional quality. Quality of onion with respect to colour, aroma and overall acceptability was better for 0.6% Potassium Metabisulphite blanched onion samples dried at 70ËšC

Download this article as