Carotenoids are a large class of yellow, red, and orange pigments derived from isoprenoids.
Carotenoids are synthesized by all photosynthetic organisms, as well as some bacteria and fungi. Animals do not have the ability to synthesize carotenoids but must obtain these nutritionally important compounds through dietary sources, typically plants. World wide Vitamin A deficiency is linked to diets deficient in pro-vitamin A carotenoids . The nutritionally important endosperm tissue of maize and wheat has a low carotenoid content and rice endosperm does not contain any provitamin A carotenoids. A content of cereal endosperms through biotechnology.