Variação geométrica de grãos de soja durante a secagem : efeito varietal

Abstract

The present study was conducted of analyzing the dependence of geometric factors (main characteristic dimensions, equivalent diameter, volume, surface area and surface-areato-volume ratio) of different soybeans varieties by function of moisture content. Besides that, was mathematically modeled the volumetric shrinkage, apparently and unitary of soybeans during the drying process, in order to indicate mathematical models for the prediction this phenomenon. It was evaluate BG 4781 IPRO, RK 8115 IPRO, SW BRIZA RR and TMG 7067 IPRO soybeans varieties. The average initial moisture content of samples was 0,32 (d.b.), with the samples dried until the final moisture content was less than 0,14 (d.b.). The soybeans were dried in an oven with a forced air flow at 40 °C, and the moisture content was accompanied by mass difference. All of these physical properties varied during drying, and it was observed reduction in surface area, equivalent diameter, main characteristic dimensions and an increase in the surface-area-to-volume ratio. The models Polynomial, Lozano and Botelho were the models that best demonstrated to fit the experimental data and were recommended to describe of volumetric shrinkage, apparently and unitary in the different studied soybeans varieties.