Evaluation of mathematical models to describe the effect of temperature

Oil uptake is one of the most important aspects about product quality during frying. The purpose of this study was to investigate the effect of temperature on oil content of final product and its perception using empirical models. Therefore, potato stripes in specified size, after blanching were fried using a fryer equipped with thermo controller at 145, 160 and 175 º C for 60, 120, 180 and 240 seconds. For separation of various stages of process surface and core temperatures of product was measured using thermocouple and data logger. Oil of samples also extracted by soxhlet method and its variation was fitted using kinetic models (Model 1 and Model 2) in MATLAB. Models were compared by R2, RMSE and also Arrhenius equation. The results showed that the equilibrium oil content (Oeq) obtained from fitting of models has inverse relation with temperature that confirms a reduction in oil uptake with increasing of frying temperature. Statistical analysis of experimental data indicated that critical temperature for reducing of oil uptake was 160 °C. The time limitation before end of surface boiling period was estimated about 160-180 seconds.