Lycopene is an pigment that gives tomatoes, watermelon and pink grapefruit their red color.

Watermelon contains higher levels of lycopene than any other fresh fruit or vegetable (15 to 20 mg per 2-cup serving) and is part of a healhty diet.

Researchers report that carotenoids (fat-soluble plant compounds that give plants red, orange and yellow pigments) may act as antioxidants that protect cells from oxygen-related damage that can result from regular cell functions.

The primary role of carotenoids in plants is to neutralize compounds created during photosynthesis. These compounds are often hydrogen peroxide or singlet oxygen, both of which will attack and destroy cell membranes, ultimately damaging the cell. Singlet oxygen is oxygen with a higher energy charge because outer orbital electrons are spinning in opposite directions.

 
Humans breathe in oxygen as O2. The biological processes in the body use oxygen for reactions, frequently creating singlet oxygen as a byproduct. The singlet oxygen is very reactive (high electric charge) and therefore must be eliminated by the body before cell damage occurs. The body uses antioxidants, compounds that look for singlet oxygen and neutralizes it. Of the carotenoids, lycopene is the most effective oxygen scavenger because it can neutralize several singlet oxygen with one lycopene molecule. Other antioxidants are Vitamin C (ascorbic acid) and Vitamin E.