Cinética de secado de cereales provinientes de la región centro del Ecuador

Abstract

The aim of the study was to determinate the drying kinetics of corn, wheat and barley grains at 3 different temperature and relative humidity conditions of 60 Celsius degrees, 50 Celsius degrees and 40 Celsius degrees. The air drying was obtained by forced convection and a constant speed of 1, 1 m per s. The physicochemical properties were evaluated in each cereal respect to the temperature such as: moisture content, grain size, mass of 1000 grains, specific weight percentge of protein content and water activity. The temperature of 50 Celsius degrees presented the lowest values in terms of moisture content, size, mass of 1000 grains and specific weight; however, the temperature of 60 Celsius degrees was the most effective temperature in terms of quality of the grains during the drying process because the protein content was much higher and the water activity was low. The experimental data were adjusted to the mathematical models of Crank, Omoto and BET, where the diffusivity coefficient (Deff) (Ks) and the activation energy (Ea) were determinated by the Arrhenius equation linearization and it`s respective correlation coefficients (R2) to each cereal. The experimental data presented good correlation because the values of the correlation coefficients obtained in the mathematical models were higher. It was also shown that the diffusivity coefficients were higher at higher drying rate, and the activation energy were lower respect to the diffusivity coefficient.