Estudo da histerese entre as isotermas de sorção e dessorção do milho BR-451.

Abstract

In the present study hygroscopic equilibrium curves of sorption and desorption of corn BR-451 a t temperatures of 10, 20, 30, 40, 50 and 60 "C and relative humidity (RH) o f approximately 0, 8, 17, 57, 87 and 100% were determined and the hysteresis effect has been analysed. With the help of experimental data equations of Henderson, modified Henderson and Chung-Pfost were tested utilising statistical package of linear, multiple and non linear regression. The equation proposed by Roa was tested as well for non linear regression. It is concluded from the present study that hysteresis decreases with the temperature increase showing a strong effect at 10 "C and a sharp decrease starting from 20 "C, an increase was also observed between the interval of 10 and 60% RH above this limit until 90% a gradual decrease occured i n a way t h a t at 100% RH virtually the effects were nullified . The maximum hysteresis observed in corn BR-451 seeds was of 4 percentage points of humidity (wet basis ) at temperature of 10 "C and RH 60% With relation to equations studied, the best fits were.