Maize Carotenoid Composition and Biofortification for Provitamin A Activity

Carotenoids are fat-soluble antioxidant vitamin compounds derived from the isoprenoid biosynthetic pathway. These natural pigments are secondary metabolites and can be divided into two classes—carotenes and xanthophylls—which play diverse biological roles in plants and animals. Carotenoids with unsubstituted β-ring end groups become more important because of their provitamin A activity. Maize is the third most staple food worldwide and also contains appreciable amount of provitamin A carotenoids with wide range of genetic variability. This makes it a good candidate crop for biofortification of provitamin A carotenoids. The quantity of provitamin A carotenoids needed to alleviate vitamin A deficiency (VAD) through biofortification depends upon its bioavailability, which is influenced by a number of factors in an individual. The bioavailability of biofortified maize can be known through determining vitamin A equivalence. Recent advances have shown that β-carotene in biofortified maize has good bioavailability as a plant source of vitamin A. So, a quantity of 15 μg provitamin A g−1 dry weight of kernel was targeted for biofortification. This chapter also includes the carotenoid biosynthetic pathway, biofortification strategies, recent advancements made toward biofortification of provitamin A, and future perspectives.