DRYING KINETICS OF SOME FRUITS

Drying kinetics of four fruits (namely, apple, pear, kiwi and banana) were studied by introducing an one-parameter empirical mass transfer m odel, involving a characteristic parameter (drying constant), as a fun ction of process variables. The model was tested with data produced in a laboratory dryer, using nan-linear regression analysis. The investi gation involved a wide range of characteristic dimensions of samples a nd air conditions (temperature, humidity, and superficial velocity). T he parameters of the model considered were found to be greatly affecte d by sample characteristic dimension and air temperature. The model al so involved the equilibrium material moisture content which was formul ated in the form of the GAB equation. Its parameters were evaluated by means of non-linear regression analysis to independent experiments co vering two process variables (temperature and water activity of the su rrounding air).