Microwave drying characteristics of Medicinal Herbs

Microwave drying is a mode of transferring or removing moisture, leading to a water vapour pressure gradient between the surface and internal part of the material similar to the conventional drying methods. So, the present work has been carried out for drying studies using microwave oven, and the following food materials which are also used as herbs are been selected i.e., Indian gooseberries (Phyllanthus emblica), Bitter gourd (Momordica charantia), Bay leaves (Laurus nobilis), and Black Pepper (Piper nigrum) The thin layer drying characteristics of herbs like Indian gooseberries, Bitter gourd, Bay leaves and Black pepper using microwave oven at five different powers were studied. An empirical model by regression methods was developed and compared the experimental and the predicted values using the model. The effective diffusivities at five microwave powers using Fick¿s equation were determined.