Natural antioxidants are those antioxidants that are found in natural sources, such as fruits, vegetables, milk and meats. There are several common natural antioxidants which are found in everyday foods, the most common of which being Vitamin C (ascorbic acid), Vitamin ? (tocopherols), Vitamin A (carotenoids), various polyphenols including flavonoids, and anthocyanins (a type of flavonoid), Lycopene (a type of carotenoid) and Coenzyme Q10. Figures show the chemical structure of some natural antioxidants (Fig. 1.1).