comparison of antioxidative effect of tea and sesame seed oils extracted by different methods

tea and sesame seed oils extracted by different methods (including supercritical fluid extraction (sfe), at a pressure of 350 atm, a temperature of 60oc, a static extraction time of 20 minutes, a dynamic extraction time of 30 minutes and 150 g kg-1 of ethanol as a modifier). solvent (se) and ultrasound-assisted solvent extraction (ue)), as natural anti-oxidants, were evaluated during 15 days storage by monitoring their effects on refined sunflower oil at 60oc. the peroxide value (pv) and the thiobarbituric acid (tba) value were used to assess the antioxidant activity of these extracted oils. the highest extraction yields were from se and sfe, while ue gave a lower yield. considering oil extraction yield and antioxidant activity, se and sfe were the preferred methods. the results showed that tea seed oil had strong antioxidant activity, which was almost equal to sesame oil. therefore, tea seed oil can be used in the same way as sesame seed oil in fat, oil and other food products as a natural antioxidant to suppress lipid oxidation.