Lycopene, a carotenoid found in plant foods, is also a red pigment. Dark red acicular crystal, soluble in chloroform, benzene and grease but insoluble in water. Unstable to light and oxygen, turning brown when met with iron. Molecular formula C40H56, relative molecular mass 536.85. The molecular structure has 11 conjugated double bonds and 2 unconjugated double bonds, constituting a straight chain type hydrocarbon. It does not have the physiological activity of vitamin A, but it has strong antioxidant function. The content is higher in the fruits of mature red plants, especially in tomato, carrot, watermelon, papaya and guava.