The effects of laurel (Laurus nobilis L.) and french lavender (Lavandula stoechas L.) essential oils on oxidative stabilities of refined sunflower and olive oil

Objective: The aim of the thesis is to examine the effects of natural laurel and French lavender essential oil supplementation in order to increase the oxidative stability of sunflower oil and riviera olive oil. Material and Methods: For this purpose, 500 and 1000 ppm laurel and French lavender essential oils were added to sunflower and olive oil samples, and sunflower oil samples were stored at 60°C for 12 days, and olive oil samples were stored at the same temperature for 20 days. During the storage period, free acidity and peroxide values, K232 and K270 values, photometric color index values and fatty acid compositions of the samples were determined. Results: The results of the study showed that the amount of free fatty acids increased during storage, but the addition of essential oil could suppress the increase. In addition, the increase in peroxide value with the supplementation of essential oil could also be prevented, and it was determined that the laurel essential oil could inhibit the increase in peroxide value at a higher rate when compared to French lavender essential oil. While the K232 value of the samples increased with storage, the K270 values, except for the samples with 1000 ppm of laurel essential oil, did not exceed the specific absorption in ultraviolet light E (270 nm) value (≤ 1,15) of olive oil according to the Turkish Food Codex. Incorporation of different essential oils had different effects on fatty acid compositions of olive and sunflower oils. Conclusion: The results of the study showed that laurel and French lavender essential oils had positive effects on protecting the oxidative stability of sunflower and olive oils.