Effect of thin layer drying on quality parameters of betel leaf (Piper betle L.)

Betel leaf or “Paan” is contemplated as “a neglected green gold of India” due to its nutritional, financial, medicinal, social and cultural values. However, surplus production of the leaves during the glut season and lack of adequate storage facilities compel the betel leaf growers to sell it at a through away price. Therefore, the current study was taken up to enhance the shelf life of the leaves by four different drying methods like shed drying, hot air oven drying, vacuum drying and freeze drying. Eight different thin layer drying models were studied and compared based on coefficient of determination (R2), root mean square error (RMSE) and chi square. The results showed that Page model was the best fitted model for hot air oven drying and vacuum drying methods, whereas Peleg model and Two Term model were found to be best fitted for shed drying and freeze drying methods, respectively. The results also revealed that both freeze drying and shed drying are the best techniques for retention of essential oil after drying. However, shed dried leaves were found to be most preferable by the panelists during organoleptic evaluation. Therefore, these dried leaves can be used for manufacturing of packaged mouth fresheners, betel leaf flavoured soup, etc.