Biological pigment general, contain six ubiquitous carotenoids: neoxanthin, violaxanthin, antheraxanthin, zeaxanthin, lutein and β-carotene. Lutein is a yellow pigment found in fruits and vegetables and is the most abundant carotenoid in plants. Lycopene is the red pigment responsible for the color of tomatoes. Other less common carotenoids in plants include lutein epoxide (in many woody species), lactucaxanthin (found in lettuce), and alpha carotene (found in carrots). In cyanobacteria, many other carotenoids exist such as canthaxanthin, myxoxanthophyll, synechoxanthin, and echinenone. Algal phototrophs such as dinoflagellates use peridinin as a light harvesting pigment. While carotenoids can be found complexed within chlorophyll-binding proteins such as
Lycopene two terminal isoprene groups of lycopene can be cyclized to produce beta-carotene, which can then be transformed into a wide variety of xanthophylls. Lycopene is the pigment in tomato-containing sauces, turning plastic cookware orange, and is insoluble in water. It can be dissolved only in organic solvents and oils. Because of its nonpolarity, lycopene in food preparations will stain any sufficiently porous material, including most plastics. To remove this staining, the plastics can be soaked in a solution containing a small amount of household bleach. Absorption of lycopene requires that it be combined with bile salts and fat to form