Étude des modèles de séchage en couche mince pour le séchage artificiel et solaire direct à convection naturelle du cacao

Abstract

Study of thin layer drying models for artificial and direct solar drying of cocoa using natural convection

The drying kinetics of cocoa beans in thin layer was studied for different conditions of drying air. The experiments are carried out in a greenhouse and in an oven at different drying air temperatures (42°C, 50°C and 60°C). The water loss evolution curves, the influence of the drying air temperature and that of the drying mode are studied in order to determine the characteristic drying curve (CCS) of cocoa. The experimental curves presented in reduced water content as a function of drying time are approximated by mathematical models existing in the literature. The statistical analysis of the results led to the conclusion that the Logarithmic model is the most appropriate for describing the kinetics of convective drying in thin layers of cocoa beans. The results made it possible to calculate the effective diffusion coefficient.

Keywords:  Cocoa beans; Mathematical models; Characteristic drying curve; Kinetics of drying