Fatores de forma e modelagem da contração volumétrica de espigas de milho durante o processo de secagem

Abstract

The objective of this work was to evaluate the effect of air temperature and moisture content on the characteristic dimensions, on the shape factors and on the volumetric contraction of corn ears during drying. For the experiment, corn ears were dried in an oven with forced air circulation at three temperatures (45, 58 and 70 ° C). Throughout the drying, measurements were taken at regular intervals of mass and principal characteristic dimensions of each spike and then determined the physical properties: roundness, sphericity, surface-volume ratio and volume. It was verified from the results that the reduction of the moisture content during drying influenced the physical characteristics of corn ears in which all the samples reduced the mean diameter, sphericity, roundness and shrinkage rate. The only exception was the surface -volume relationship, which showed an increase in its magnitude. The effect of the drying temperature was evidenced in the sphericity and roundness of the analyzed ear corn. The Bala and Woods, Exponential, Linear, Polynomial and Rahman models satisfactorily described the volumetric contraction during drying.