Determination of the changes in sunflower oil during frying of leavened doughs using response surface methodology

In this study, the effect of dough salt content, frying temperature and time on the conjugated diene values, polymer triglyceride content, total polar material content, viscosity, and color values of the sunflower oil during frying of leavened doughs was determined using response surface methodology. Fifty repeated frying operations were applied in the same day at 160-200 °C for 1-5 min and doughs with 0-2% salt content. According to the results of the study, frying temperature, frying time and dough salt content were significantly (p < 0.05) affected total polar material content, polymer triglyceride content, viscosity and a* and b* color values of oil samples, whereas dough salt content did not affect the L* color values and conjugated diene value of oil significantly (p > 0.05). To minimize the oxidation products of frying oil, the frying process can be applied at 160 °C for 1 min using dough with 1.97% salt content.