The study explores the effect of onion (allium cepa l.) drying using hot air dehumidified by activated carbon, silica gel and zeolite

Abstract

Dehumidified air can be used to reduce the drying time. A batch-type tray dryer with hot air dehumidified by three different desiccants (i.e. activated carbon, silica gel and zeolite) were carried out to determine the optimum drying time. This study concerns the comparison of the between those desiccants. One mm sliced onion were dried at controlled temperature (40°C, 50°C, 60°C and 70°C). The weight of the samples were measured every 10 minutes for two hours. Results indicate that hot air dehumidified by zeolite gives the shortest drying time compared to the activated carbon and silica gel. Page and modified Page models are the most suitable model to experiment with the value of R2 (0.8971 - 0.9588). The highest k value (0.6132934) is achieved through the treatment at temperature 70°C using zeolite.