SINGLE-LAYER DRYING OF PURPLE YAM (DIOSCOREAALATA L.) SLICES

Junaedi Muhidong, Salengke Salengke, Andi Surestyana

Abstract: This research was intended to find the best fitted model to represent the drying behaviors of purple yam slices during singlelayer drying process. The research was conducted at Food Processing Laboratory of Agricultural Engineering Department, Hasanuddin University – Indonesia. Two levels of drying temperature (40 and 50°C) under two different air velocities (1.0 and 2.0 m.s-1) were applied. A tray dryer (Model EH-TD-300 Eunha Fluid Science) was utilized as the main equipment. The moisture ratios resulted from each drying treatment combination was determined and nine different thin-layer models were fitted to these moisture ratios. The results indicated that all models performed well as shown by their high R2 values (> 0.9) with small χ2 and RMSE values. However, among all models, the Midili-Kucuk model consistently showed the best goodness of fit. It was also found that air velocity affected the drying rate of the purple yam slices. Another fi nding, the drying rates resulted from the drying air temperature of 50°C with the air velocity of 1.0 m.s-1 and the drying air temperature of 40°C with the air velocity of 2.0 m.s-1 were relatively close.

Keywords: moisture ratio; purple yam; single-layer drying

Date published: 2018-03-07