Modeling of convective drying of safed musli (Chlorophytum borivilinum).

Abstract

The drying kinetics of Safed musli (Chlorophytum borivilinum) in terms of moisture content, moisture ratio, drying time and drying rate was investigated. A laboratory model dehumidified air dryer and a hot air dryer (Tray dryer) were employed to study the drying behavior at 30, 35, 40 and 45°C. Safed musli drying primarily occurred in falling rate period. The drying data were fitted to seven thin layer drying models and the two-term model satisfactorily described the drying behavior of safed musli roots with highest coefficient of determination (R2) and lowest chi-square (c2), root mean square error (RMSE) and mean bias error (MBE) values except at 30°C in dehumidified air dryer where logarithmic model was found as the best model having the highest R2 and lowest c2, RMSE and MBE values. Effective moisture diffusivity (Deff) of safed musli was found to increase with the increase in drying air temperature and it ranged from 2.23010 × 10-7 to 4.43057 × 10-7 m2/s. The results of the study are very useful for commercial scale drying of safed musli to optimize drying process and to achieve superior quality of dried product. Key words: Drying, dehumidified air dryer, tray dryer, safed musli, modeling.