Abstract
On the basis of the results obtained from these investigations, it appears that the following summary is justified.
(1) The evaporated water was found to inclease in value when the drying temperature incleased under any given condition of constant relative humidity, but it was not so clear in contrast with this.
(2) There were so large differences among equilibrium moisture contents Me, calculated from three voluntary portions. It was found that the drying constant K is a function of the temperature of the drying air. This method of calculating the equilibrium moisture content may make up higher value than the one observed. Further study on the determining of the Me appears advisable.
(3) The isotherms were constructed by plotting for each temperature the equilibrium moisture content values (dry basis), as ordinates against the corresponding values of relative humidity on the abscissas. Those resulted from the data of natural soybean were nearer to the abscissa than these from remoistened soybean. It may indicate that there is possibility of the presence of the hysteresis loop between those and these isotherms. The curves of these isotherms obtained in these investigations depart from one of Henderson's especially in the range of higher relative humidity.
(4) The straight line was obtained when the function ln M-Me/M0-Me is plotted against the time. the slope of the straight line gives the value of the drying constant K, and the segment gives that of constant a, dependent on particle shape directly. There was the high correlation between K and a, and lnK found to be the function of the 1/T.
(5) The air-oven method of measuring the moisture content of soybean will give higher results possibly indicating the presence of volatile ingredients and the dehydration of carbohydrates in soybean during the heating. This improvement may be gained only at the comparison with other various methods.
