Heat Transfer During Frying of Potato Slices

The convective heat transfer coefficient during deep-fat frying of potatoes was determined at different temperatures. The temperature, 0.1 cm below the top and bottom surfaces of a 0.05×0.05×0.005 m potato sample was monitored over time. The thermal conductivity and specific heat of the sample were expressed as a function of time, and the data were analyzed using the heat transfer equation with an explicit finite difference method. Crust formation occurred primarily at the bottom surface of the potato slice. Therefore, the frying was examined at the bottom surface; before and after the crust formation. The convective heat transfer coefficient ranged between 300 to 335 W / m2°C for the top, and 450 to 480 W/m2°C for the bottom surface before crust formation. After crust formation, it varied between 70 to 150 W/m2°C for the bottom surface within the studied temperature range of 150 to 190 °C.