Thin-layer drying behavior of West Indian lemongrass ( Cymbopogan citratus ) leaves.

The objectives of this study were to investigate the effect of temperature (40, 50, 60, and 70°C), and air velocity (0.5, 1, and 2 m/s) on the drying behavior of West Indian lemongrass ( Cymbopogan citratus ) leaves. Drying was carried out in a computer-controlled tray dryer. Overall, the effect of temperature was seen to be more important than that of air velocity, but the air velocity did have an effect on drying rates at the start of the drying process at 50-70°C. Drying rate constants, diffusivity values, and activation energy were determined. Twenty-two empirical and semiempirical thin-layer models were tested, and although model fit varied, the Midilli model could be applied to all data with reasonable prediction of MR values.