CHARACTERISTICS AND MATHEMATICAL MODELING OF CONVECTIVE DRYING OF QUINOA (CHENOPODIUM QUINOA WILLD.): INFLUENCE OF TEMPERATURE ON THE KINETIC PARAMETERS

摘要

The aim of this research was to model the drying kinetics of quinoa and to evaluate the temperature influence on the kinetic parameters of the models used. Prior to drying process, quinoa grains were washed at 60C and the removal of saponins was studied. Hot air drying temperatures were 40, 50, 60, 70 and 80C. Initial saponin content was 6.34%, reaching a final saponin content of 0.25% after 120 min of washing. Sorption isotherm was determined at 60C giving a monolayer moisture content of 0.051 g water/g dry matter. Drying kinetics was modeled with different equations. Diffusional coefficient increased with temperature from 3.78 to 7.67× 10~(-11) m~2/s, for a range of temperatures between 40 and 80C, with an estimated of Ea 15.95 kJ/mol. According to the statistical tests used, the logarithmic and Weibull models gave the best fit for experimental data (determination coefficient > 0.98, sum squared error < 0.001 and Chi-square < 0.001).