MODELING OF THE VOLUMETRIC SHRINKAGE OF SOY BEANS DURING THE DRYING PROCESS

Abstract

The determination and quantification the rates of volumetric shrinkage can help to optimise the drying process, since, this rates enable foretell the volume occupied by the mass of grains. Therefore, this study aimed to evaluate the volumetric shrinkage of soy beans during the drying process and adjust different mathematical models to the experimental values obtained as a function of moisture content. It was used the NS7901RR and TMG132RR soy beans variety, of initial moisture content of 0.30 dry basis (d.b.). The soy beans were dried in an oven with a forced air flow at 40, 50 and 60 °C temperatures unti lthey reach a moisture content of at least 0.15 (db). The volume reduction was measured as a function of moisture content by different way sof mathematical models. The models adjustment to the observed data were analyzed, overall, by evaluating the magnitude of the error made in the volumetric shrinkage values estimation. The models Bala & Woods adapted and Polynomial, for the NS7901RR variety, and Corrêa, Exponencial, Linear, Lozano, Mayor and Polinomial for the TMG132RR variety, were the models that best showed to fit the observed data of the volumetric shrinkage, apparently and unitary to the different used drying air temperatures.