Vijay Pandey

Defensive Mechanism of Natural Antioxidants

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).

Each natural antioxidant is available in vastly different sources and is consumed in a different manner. Some are consumed as fruits, vegetables in the fresh or processed forms. Others are taken in the form of drinks like tea, wine, fruit juice etc. (Table 1.1).

Compound NameNatural source
Vitamin C (ascorbic acid)

Most citrus fruits, some vegetables, tomatoes

Vitamin E/Tocopherols

Cereal grains, broccoli, sprouts, cauliflower,

cooking oils (olive, sunflower, safflower), almond, hazelnuts

Beta-Carotene

Vegetables such as red paprika, spinach, parsley, and tomatoes, carrots, sweet potatoes, apricots, papayas

Flavonoids (a type of polyphenol)

Potatoes, tomatoes, lettuce, onions, wheat, dark chocolate, Concord grapes, red wine, black tea

Anthocyanins (a type of flavonoid)

High content in red wines, some in whiskey

Various polyphenols

Teas (mainly green, some rooibos), as well as many red/purple hued fruits or vegetables, such as Concord grapes, red cabbage, blueberries, blackberries etc.

Lycopene

Tomatoes, papaya, watermelon, pink grapefruit, guava, the skin of red grapes

CoQ10 (an antioxidant enzyme)

Wheat bran, fish, viscera meats (e.g. Chicken liver)

Types of Natural Antioxidants

β-carotene (which can be thought of interchangeably with Vitamin A) is a fat-soluble antioxidant member of the carotenoid family. Vitamin A is mostly found in vegetables and fruits such as carrots, sweet potatoes, apr

Compound NameHow to optimize consumption
Ascorbic acid (Vitamin C)

Compound NameHow to optimize consumption
Ascorbic acid (Vitamin C)

Phytochemicals are not classified as vitamins, but they can contribute greatly to health and wellbeing.