There are several methods to prevent oxidation of oils, one of which is the addition of synthetic antioxidants. However, due to the fact that synthetic antioxidants have undesirable effects, such as the effect of mutagenicity and carcinogenicity in human body, it is necessary to investigate the sources of natural antioxidants in order to replace synthetic compounds. In this study, methanolic extract of Anacyclus pyrethrum root were extracted. Extracted extract were added to sunflower oil at different concentrations (200, 400, 800 and 1600 ppm) and the amount of phenolic compounds and free radical inhibitory activity as well as oxidative stability of oil at 65 ° C for three days was investigated by measuring the TBA and finally compared with the synthesis antioxidant BHT at 200 ppm. In general, the results showed that by increasing concentration of Anacyclus pyrethrum root extract in sunflower oil from 200 to 1600 ppm in one fix time, the amount of phenolic compounds and inhibitory activity of free radicals increased while the TBA index decreased.
