The Principle of Some In vitro Antioxidant Activity Methods: Review

The antioxidant is defined as any substance that could delay or prevent oxidative damage by free radicals. The antioxidant inhibits the oxidative damage by free radicals through several mechanisms. The sources of the antioxidant are abundantly available in nature and can be found in the daily diet such as fruit, vegetables, seeds, nuts, leaves, roots, and barks. Several major compounds identified as antioxidants such as polyphenols, vitamins, and carotenoids. This article provides ageneral summary of the most common in vitro methods for determining antioxidant activity. It emphasizes the working principle, methodology, advantages, and disadvantages of different methods. The determination of antioxidant activity could not only follow one single approach due to the diversity of antioxidant mode of actions. Therefore, the choices of the appropriate method of analysis need to be considered to achieve the purpose of the research.