DRYING AND REHYDRATION CHARACTERISTICS OF SOUR CHERRY (PRUNUS CERASUS L.)

The effect of air temperature and velocity on the drying kinetics of sour cherry was investigated using a laboratory scale static-type dryer at air temperatures of 60, 70 and 80C and air velocities of 0.3, 0.6 and 0.9 m/s. The Weibull distribution model was fitted to experimental data using nonlinear regression analysis techniques in the MATLAB computer program. The high regression coefficients (R(2) > 0.998) and low reduced chi-square and root mean square error indicated that the Weibull model is suitable for predicting moisture ratio. Correlations of the Weibull model constants with the variables T and V were determined. The effective diffusivity of sour cherry varied between 3.46 x 10(-9) and 13.08 x 10(-9) m(2)/s. The activation energy of sour cherry was in the range of 64.39-66.05 kJ/mol. Rehydration tests indicated that the rehydration capacity of dried samples at air temperature of 70C and air velocity of 0.3 m/s is better than other experiments.