PHYSICAL PROPERTIES OF DIFFERENT SOYBEAN CULTIVARS DURING DRYING

ABSTRACT The knowledge of physical properties of grains is important for the optimization of postharvest operations. Thus, this study aimed to evaluate the effect of moisture content over physical properties of different cultivars of soybean. Soybean of cultivars NS7901RR, TMG1180RR, P98Y70 and TMG132RR were used, with initial moisture content of 0.32, 0.27, 0.25 and 0.21 dry basis (d.b.), respectively. In order to dry the samples, an oven of forced air circulation was used. Samples were dried at temperature of 50 °C, being the drying procedure stopped when the moisture content of soybean was equal or inferior than 0.15 (d.b.). During drying, for interested moisture contents, physical properties were determined: bulk density, equivalent diameter, sphericity, circularity and surface/volume ratio. It was noticed that all physical properties analyzed presented a direct relationship with moisture content. With exception of the equivalent diameter, all the remaining physical properties increased linearly with moisture content reduction. Physical differences were observed among soybean cultivars during drying. However, variation of analyzed properties occurred in different proportions during drying for each cultivar.