What is Lutein?
Lutein ( from the Latin "luteus" meaning "yellow") is one of over 600 known naturally occurring carotenoids. Found in green leafy vegetables such as spinach and kale, lutein is employed by organisms as an antioxidant and for blue light absorption.
Lutein is also found in egg yolks, animal fats and the corpus luteum. The presence of the long chromophore of conjugated double bonds (polyene chain) provides the distinctive light-absorbing properties.
Lutein is a xanthophyll, like its sister compound zeaxanthin. It has primarily been used as a natural colorant due to its orange-red color. Lutein absorbs blue light and therefore appears yellow at low concentrations and orange-red at high concentrations.
Lutein is used in chicken feed to provide the yellow color of broiler chicken skin. Polled consumers viewed yellow chicken skin more favorably than white chicken skin. Such lutein fortification also results in a darker yellow egg yolk.