Studying the Effect of Different Drying Bed on Drying Characteristic of Mint Leaves

Abstract

Abstract Mint leaves are aromatic, almost exclusively perennial, rarely annual, herbs. Drying of mint leaves guarantees a longer shelf time while preserving its quality for use in pharmaceutical and food industries. In this study, the drying behavior of Mint leaves in a fluidized bed dryer (FBD) under different drying conditions (fixed, semi-fluidized and fluidized) and 4 temperature levels (30, 40, 50 and 60 °C) was investigated. The experimental data was assessed using semi-theoretical and experimental models. Finally, Page’s model was selected as the best model based on its R2, χ2 and RMSE values. Findings showed that the effective moisture diffusivity of Mint leaves ranged between 0.91 × 10–11 and 10.41 × 10–11 m2/s. The activation energy was also between 60.82 and 65.59 kJ/mol. The results of statistical analyses also showed that drying time was significantly reduced with increasing air velocity (changing drying bed from fix bed to fluid bed).