Ajowan seed ethanolic extract: extract optimization, phenolic compounds and antioxidant properties

Oils and fats under the influence of several factors such as oxygen, light, heat, metal ions and enzyme are oxidized. Use of synthetic antioxidants due to the possibility of toxicity and carcinogenicity, has been under questioned. The aim of this study was to optimize the extraction conditions of Ajowan seed extracts and evaluate their antioxidant properties. In this study Ajowan seed under different concentration of solvents (water and ethanol in 0, 50 and 100% concentration), extraction time (0.25, 12 and 24 hours) and different temperatures (20, 50, 80 °C) were prepared. The optimal extraction conditions were defined by response surface methods and extraction was performed at the optimum condition. Then different concentrations (0.2, 0.4 and 0.6%) of optimum extracts were prepared and added to the non- containing antioxidant soybean oil. All treatments were kept under 90 °C for 5 days. Acidic value, peroxide value and thiobarbituric acid (TBA) were performed on each treatment in every day. Data analysis showed that addition of water to the solvent increased phenolic compounds extracts and antioxidant activity. According to the results of the thermal stability of soybean oil, the best results were related to BHT and other higher concentrations of ethanolic extracts. The results of the present study showed that the ethanolic extracts of Ajowan seed can be used as natural antioxidants in the formulation of edible oils.