Mathematical modeling for heat conduction in olive fruit

This study aims to develop a numerical model that can simulate the heat transfer in spherical coordinates and predict the temperature of olive fruit during the thermal process. The first step was to measure or estimate the thermophysical properties of olive fruit. The fixed grid finite difference method with an explicit scheme was used to solve the heat transfer equation. The product had an average geometric diameter of 18.18 mm, a bulk density of 556 kg/m3, a porosity of 48% and a specific heat of 3180 kJ/kg. The inverse method was used to determine the thermal conductivity of olive fruit, which was 0.44 W/m°C. The model was validated by comparing the predicted values with the experimental temperature profiles obtained during the thermal process of the fruit (correlation coefficient higher than 0.99 and mean squared error lower than 1.8°C). The sensitivity coefficient results indicated that the surrounding temperature and the diameter of the product were the most influential parameters on the heat transfer of the product. The model was effective in simulating the thermal processing of olive fruit. The research results can be applied to optimize the pasteurization process of olive fruit.