EFFECTS OF INITIAL MOISTURE CONTENT AND HEATING RATE ON WHEAT (OAKES) DRYING KINETIC PARAMETERS

The goal of this study was to determine the effects of initial moisture content an d hea ting rate on the drying kinetic parameters of wheat under non - isothermal conditions. Wheat (OAKES) samples at initial moisture contents of 20.7%, 18.5%, 16.8%, and 14.8% wet basis (w.b.) were dried using a thermogravimetric analyzer. The analyzer was set at five heating rates (2, 3, 4, 5 and 10 o C/min) to determine the drying kinet ic parameters, i.e., activation energy, of the heated samples from room temperature of 30°C to 170 o C. The experimental moisture ratio data were fitted to the four empirical models, namely Page, Newton, Logarithmic, and Henderson models. The goodness of fit criterion was used to determine the best - fitting model. Heating rate and initial moisture content affected the activation energy required for drying wheat. Increasing the heating rate expedited the drying curve. The heating rate of 10°C/min for wheat at an initial moisture content of 14.8% w.b. resulted in the greatest activation energy of 28.174 kJ/mol. The heating rate of 2°C/min for wheat at an initial moisture content o f 20.7% w.b. resulted in the lowest activation energy of 14.760 kJ/mol. The Logarithmic and Henderson models were adjudged as best fit models for the entire drying curves by R 2 , RMSE, and X 2 . This study highlighted that the energy required to dry wheat fro m 20.7% w.b. to acceptable safe level could be minimized by reducing the heating rate