These compounds are the best natural antioxidants due to their biological activity. They can protect oil to a good extent without decreasing the sensory properties of fried food. However, these antioxidants are more effective at storage conditions than frying . The order of effectiveness found for antioxidants in heated oil was TBHQ > lecithin > ascorbyl palmitate > rosemary extract > BHT, BHA, D-𝝳-tocopherol, although this order can show some variations according to the condition of heating . Refined sunflower oil was fortified with 1000 ppm of rosemary extract, followed by exposure to thermal oxidation conditions at a temperature of 180 °C. It was reported that rosemary extract extends the oxidative stability from 7.52 to 13.5 hours .