Generally, the antioxidant activity of phenolic compounds depends on their structure but also and especially on the chemical entities existing in the molecules. In general, scavenging activity of phenol compounds increase with the number of hydroxyl groups
OH. It should be further noticed that the synergistic effect existing between the phenolic compounds can improve the antioxidant activity of the extract. However, these mechanisms are at present low mastered. After studying its antioxidant effect, the rosemary extract was added to the mixture of soybean and sunflower oils at a proportion of 800 mg/kg. This percentage was also chosen in reference to other studies. According to Ramalho and Jorge, an amount of 1.000 mg/kg represents the highest proportion commercially recommended.