AJUSTE DE MODELOS MATEMÁTICOS NA SECAGEM DE SEMENTES DE GIRASSOL (Helianthus annuus L.)

Abstract

Sunflower is an oilseed that stands out for its multiple purposes of use, showing good ability to adapt to different edaphoclimatic conditions and can be farmed in different locations. The objective was to study the drying kinetics of sunflower seeds at different drying temperatures, and to apply the adjustment of mathematical models to the experimental data. Sunflower seeds (cultivar Altis 99). Seed drying was carried out in an oven with forced air circulation, adjusted to operate at temperatures of 40, 50, 60, 70 and 80 °C. The monitoring of mass reduction during drying was monitored by weighing at pre-established intervals. Ten mathematical models were fitted to the experimental data of water content ratio, from non-linear regression analysis by the Gauss Newton method. The significance of the parameters of the models was evaluated by the t test adopting the 5% significance level. The degree of adjustment of each model was verified according to the magnitudes of the coefficient of determination (R2), the mean relative error (P), estimated mean error (SE), Chi-square test (χ2) and the AIC and BIC. It is concluded that the water removal rates from sunflower seeds are directly proportional to the increase in drying temperature, being necessary under these conditions, shorter drying time. The Midilli model is recommended to describe the drying curves, since it presented the best statistical coefficients for most of the temperatures under study and due to its simplicity of application.