Drying characteristics of mint leaves (Mentha arvensis) dried in a solid desiccant dehumidifier system.

In this present study, solid desiccant-based pressure-swing adsorption (PSA) dehumidifier was developed and the process parameters were optimized to deliver the air continuously at 0.1% relative humidity. Mint (Mentha arvensis) leaves are tested to study the drying characteristics at varied flow rates of dehumidified air in the drying chamber. The initial moisture content of 5.059 g water/g dry matter have been reduced to a safe storage level in 360 min at 0.160 m3/min volume low rate. The effective moisture diffusivity of the mint leaves was found in the range of 2.07534 × 10-11m2/s to 3.45817 × 10-11m2/s. The percentage of retention of ascorbic acid in dried mint leaves is increased by an increase in the volume flow rate of dry air and a maximum of 70.11% is achieved by 0.160 m3/min. The colour measurement and chlorophyll content of the dried samples indicated that the desiccant dehumidified air dryers are suitable for heat sensitive green leafy vegetables. © Association of Food Scientists & Technologists (India) 2020.