Drying Characteristics of Purslane (Portulaca oleraceae L.)

Abstract

Thin layer drying rates of purslane were determined experimentally as a function oftemperature. Thin layer drying data were obtained for purslane in four temperatures (35, 70, 95and 120C). Five empirical drying models (diffusion model, exponential model, Page model,two-term exponential and Thompson model) were fitted to the drying data. The color of purslanewas determined after drying using spectro-colorimeter (Hunter Lab) in terms of Hunter L, a, andb values. The two term exponential and Page models were found to be most suitable indescribing the drying characteristics of purslane. New parameters developed for the modelsresulted in a good fit at different temperatures. Color measurement indicated that greennessdecreased with an increase in drying air temperature. Typical drying times were 88, 139, 416and 1372 minutes at drying temperatures of 120, 95, 70 and 35C respectively.