CINÉTICA DE SECAGEM E CARACTERIZAÇÃO FÍSICA E QUÍMICA DOS GRÃOS DE SOJA

Abstract

Soybean is an oilseed recognized for having high protein and lipid contents, being regularly subjected to the drying process to increase its shelf life and preserve its properties. Aiming to evaluate the grain kinetics at 5 different temperatures (40, 55, 70, 85 and 100 °C) together with physical analyzes (intergranular porosity, volume, sphericity, circularity, unit and apparent specific mass) and proximal composition ( lipids, proteins, ash and water content) of dry grains with a final water content of 13% on a dry basis (b.s.), and a control sample with an initial water content of 20% on a wet basis (b.u.). The drying time for each treatment was 32.5; 31.0; 22.0; 19.5 and 18.0 hours for the respective temperatures of 40, 55, 70, 85 and 100 ºC. Both physical analyzes showed significant differences in the treatments, since the grains did not undergo a selection process of physical uniformity of the soybean, resulting in a coefficient of variation of 29% of the volume parameter. There was a decline in porosity, specific gravity and protein content with increasing drying temperature. And in the proximal analysis, the temperature of 85 ºC showed a good performance, because even with the significant difference between the treatments, their values ​​of lipids, proteins and ash showed higher levels. It is concluded that the shortest kinetics time and the highest proximal values ​​are satisfactory for the industrial processing of soybeans, showing that the temperature of 85 ºC stood out in these parameters.