Comparison of Drying Kinetics for Small Fruits with and without Particle Shrinkage Considerations

Experimental values of volume and area changes for sweet (Prunus avium) and sour (Prunus cerasus) cherry and rose hips (Rosa rubiginosa) measured in previous works were analyzed to propose generalized correlations for the three fruits which predicted with low errors. The correlation developed is lineal and the highest errors were observed for fruit water contents corresponding to storage stability values. The shape factors were measured for the fruits, which were close to spherical values as the fruits dried. This would enable the assumption of spherical shape to calculate characteristic dimensions used in modeling. Moreover, the predictions of kinetic models were compared with experimental data for three radii: the initial, assumed constant; variable, estimating the radius with the correlations published for each fruit; and variable, calculating the radius with the generalized correlation developed in this work. The RMSE between the experimental data and the predictions by the kinetic model were between 0.321 and 0.562; 0.021 and 0.111; and 0.020 and 0.093, respectively.