Modelling of drying kinetic of potatoes taking into account shrinkage

A natural convection oven with controlled air temperature, vision and weighting system interfaced with computer was used to obtain the drying kinetics data. Spherical potatoes samples with 10 mm diameter are used in the experiments. During drying, the operating conditions carries out inside the oven are an air temperature of 60 °C and absolute humidity of 5 kgH2O/ 100 kg dry air. Shrinkage models’ are tested to describe gradually the particle size reduction over time. Based on data analyses, a diffusive model, numerically solved by the method of finite control volumes, to describe the drying kinetics of potatoes considering the effect of shrinkage on mass transfer is proposed. The simulated data show a good agreement with the experimental ones as it can be proved by the significant correlation coefficient (r = 0.9984) and low maximum experimental error (4.15%) achieved.