Three-dimensional modeling of coupled momentum, heat, and mass transfer during potato frying: Effects of oil temperature, type, frying load, and fryer heating cycles

The present study offers a mathematical model to optimize the frying process of potato slices by considering interactions between oil temperature (150, 170, 190 °C), oil type (canola, sunflower, and soybean), and frying load (potato/oil ratio: 1/10, 1/15, and 1/20) on the distribution of velocity, temperature, moisture loss, and oil absorption. The moving boundary problem was considered in the current model, and the boundary between the crust and core of potatoes was differentiated. Moreover, heating on/off cycling of the fryer element was included in modeling as a function of time. The results demonstrated that the highest oil velocity was observed for soybean oil at 170 °C and the 1/10 frying load. The interaction of oil temperature and frying load significantly affected moisture loss and oil absorption of the fried product, with the highest oil uptake recorded at the highest and lowest oil temperature. The developed model effectively showed the protective role of water vapor and crust formation in reducing oil uptake. Furthermore, the results highlighted the crucial impact of fryer element's heating on/off cycling on the distribution of oil velocity and temperature. Due to a physics-based modeling approach, the developed model may be employed in other food processes involving similar transport phenomena.