Advances in Research on Natural Distribution, Biosynthesis, Detection, Bioactivity, and Application of Lutein

Lutein, [(3R,3′R,6′R)-β,ε-carotene-3,3′-diol], is a C40 hydroxyl carotenoid. Its chemical structure is based on an unsaturated polyene chain skeleton, and there are one ε-ring and one β-ring on both sides of the skeleton, with a hydroxyl group on the 3′ site of each ring. Lutein is one of the important lipophilic isoprenes from mainly plants and algae. The wide range of sources makes the study of lutein quite comprehensive. The biosynthetic pathway and biochemical activities of lutein have been extensively studied and revealed. Lutein has been extensively studied for its important bioactivity, including for use in functional foods and medicines for brain health, eye-related diseases, skin health, and cancers. This review of lutein summarizes the major studies on bioactivity, metabolism, stability, digestive absorption, lutein delivery systems, and biotechnology.