Natural antioxidants enhance the oxidation stability of blended oils riched in unsaturated fatty acids

Background Rancidity causes the unpleasant tastes, smells, the degradation of fatty acids and natural antioxidants, so that the oil is unfit to be consumed. Natural antioxidants, including tocopherols, polyphenols (sesamol, canolol, ferulic acid, caffeic acid, etc.), β-carotene, squalene, and phytosterols, contributed to delay the oxidation of vegetable oils. However, studies on the combination of natural antioxidants to lengthen the shelf life of unsaturated fatty acids-rich blended oil have not been reported. Results All of the composite antioxidants had the potential to significantly improve the oxidation stability of blend oil. Blended oil G with 0.05 g/kg β-carotene, 0.25 g/kg sesamol, 0.25 g/kg caffeic acid showed the best anti-auto-oxidation. It is also effective in improving the oxidative stability of vegetable oils containing various fatty acids. The OSI of the blended oil containing the optimum composite natural antioxidant was 2.17-fold longer than control sample. After the end of accelerated oxidation, the oil's POV, p-AV and TOTOX were 6.59 times, 12.26 times, 6.65 times lower than control sample, respectively. Conclusion (1) The combination of natural antioxidants β-carotene 0.05 g/kg, sesamol 0.25 g/kg and caffeic acid 0.25 g/kg enhances the oxidative stability of unsaturated fatty acid-rich blended oils. (2) β-Carotene is the main antioxidant in the early stages of oxidation. (3) Sesamol and caffeic acid are the main antioxidants in the middle and late stages of oxidation. This article is protected by copyright. All rights reserved.