Free and bound phenolic and flavonoid compounds of Ferula persica obtained by different extraction methods and their antioxidant effects on stabilization of soybean oil

In this study, the maceration and ultrasound-assisted extraction methods were used to extract free and bound phenolic and flavonoid compounds from Ferula persica. The results revealed that F. persica extract obtained at 75% sonication amplitude had higher contents of free and bound phenolics and flavonoid compounds than those extracted at 50% sonication amplitude and maceration. Due to the higher antioxidant activity of free F. persica extract obtained at 75% sonication amplitude than other F. persica extracts, it was added to soybean oil to evaluate its antioxidant ability. Peroxide value, carbonyl value, conjugated dienes number, and oxidative stability of the oil were investigated under accelerated oxidation process (60 degrees C for 72 h). The oil samples containing 400 ppm free phenolic compounds presented remarkably higher chemical and oxidative stability compared to the control and TBHQ-incorporated oil samples. These results suggested that F. persica extract can be used as a naturally bioactive agent and a superb alternative to synthetic antioxidants in food industry.