Characteristic Curves of the Codfish Drying Kinetics with Thin-Layer Simulation Models

Abstract

The correct definition of drying procedures of a vast range of products is crucial in what concerns energy minimization and minimal time of kiln residence without compromising the final product's quality. Several external parameters namely, air temperature, relative humidity and velocity, influence the time required to reduce the moisture content of the product. For whole salted codfish, drying prevents the utilization of temperatures above 20–22C, because they lead to an inevitable deterioration of the product. Taking into account these limitations, whole codfish convective drying kinetics were determined for a temperature of 20C, initial moisture contents comprised between 57 and 65% (wet basis), air velocities of 1.5 and 3 m/s and drying air relative humidities of 40 and 70%. A semi-empirical drying model was developed and validated. The results show that lower relative humidities led to faster drying and that air velocity influences drying rates particularly at high relative humidities. PRACTICAL APPLICATIONS The focus of this work is the codfish drying process, through laboratory experiments and mathematical models. The present article contributes toward the advancement of the knowledge of the drying kinetics of codfish, hence, providing guidelines for a future optimization of the drying process, aimed at reducing energy consumption in installation, drying time and improve final product's quality.