Comparative study on the total phenolic content and radical scavenging activity of common edible vegetable oils

Abstract

The study investigates the antioxidant potential of commonly used vegetable oils viz., coconut (CNO), sunflower (SFO), rice bran (RBO), groundnut (GNO), sesame (SESO) and mustard oil (MO), where the oils were extracted with methanol; and these methanolic extracts were used for the antioxidant studies. Fatty acid composition by gas chromatography, physicochemical parameters such as specific gravity, refractive index, acid value, iodine value and peroxide value were also analysed. Total phenolic content (TPC) and antioxidant activities of the oils (DPPH, ABTS, superoxide and nitric oxide radical scavenging assays) were evaluated. Phenolic compounds were identified by high-pressure liquid chromatography (HPLC). Percentage TPC was highest in groundnut oil with 3.09 mg/100 g oil followed by coconut oil, rice bran oil, mustard oil, sunflower oil and sesame oil with 1.8, 0.89, 0.56, 0.49 and 0.33 mg/100 g oil, respectively. The methanolic extracts of oils showed potential antioxidant activity in terms of super oxide and nitric oxide radical scavenging activity.