Oxygen is a reactive molecule, which can damage living organisms by producing reactive species. To prevent this, organisms have antioxidant systems that prevent reactive species from being formed, or remove them before they damage the vital components of the cell. Since reactive oxygen species also tend to have important cellular functions, antioxidant systems do not entirely remove oxidants but keep them at an optimum level. Some of the reactive oxygen species produced in cells include hypochlorous acid, hydrogen peroxide and free radicals. This book includes some of the vital pieces of work being conducted across the world, on various topics related to antioxidants and their importance for human health. Most of the topics introduced herein cover the chemical, biological and functional properties of antioxidants. This book, with its detailed analyses and data, will prove immensely beneficial to professionals and students involved in this area at various levels.