Modeling of quality changes of chicken nuggets during deep frying at different frying temperatures

In this study, frying of chicken nugget samples was carried out in deep fat at three different temperatures (160°C, 170°C and 180°C) for 180 seconds. Mass transfer parameters of chicken nugget samples were calculated. It was observed that the effective moisture diffusion coefficient increased with increasing oil temperature. The effective moisture diffusion coefficient values were calculated as 2.74×10-8, 8.22×10-8 and 13.69×10-8 m/s, respectively. In addition, an Arrhenius-type relationship between the effective moisture diffusion coefficient and oil temperature was determined and the activation energy was found to be 128.81 kJ/mol. In the study, the transfer coefficient values of oil absorption were also determined. The transfer coefficient values of oil absorption of the samples were calculated as 0.0082, 0.0091 and 0.0094 s-1, respectively. As the frying temperature increased, the transfer coefficient of oil absorption increased while the equilibrium oil content values decreased. The effect of temperature on the equilibrium oil content values was again determined by Arrhenius type equation and the activation energy was calculated as -35.63 kJ/mol. Various analyses were performed to determine the changes in some quality parameters and nutrient contents during the frying process (pH, color, oil uptake and texture parameters). Among the quality parameters analyzed, pH values were found to be statistically different from each other. At the end of frying at 160, 170 and 180°C, the pH values of the samples were measured as 6.12±0.00, 6.08±0.01 and 5.99±0.00, respectively. While a decrease in L* values of the samples was determined with the increase in frying temperature, no clear decrease or increase in a* values was detected. In addition, an increase in b* values was determined as a result of the frying process at 160°C, while a decrease was determined at the end of the frying processes at 170°C and 180°C. It was determined that there was an increase in the hardness, springiness and chewiness values of the samples as the frying temperature increased, while there was no statistically significant change in the cohesiveness values.