α‐Carotene, one of the C40 carotenes, is a natural lipid‐soluble terpene. The chemical structure of α‐carotene is based on the unsaturated polyene chain skeleton, with an ε‐ring and a β‐ring on each side of the skeleton. α‐Carotene is widely found in dietary fruits and vegetables, and the concentration depends on the plant species. In addition, processing methods and storage conditions used in the food and medical industries can alter the concentration of α‐carotene in raw materials. This review of α‐carotene summarizes the major studies on chemical structure, source, extraction, detection, biosynthesis, processing effect, bioactivity, medicine, and biotechnology. Whether α‐carotene supplementation or a diet rich in fruits and vegetables has a positive effect on the prevention of cancer, cardiovascular disease, and other diseases is the focus of this study. © 2022 Society of Chemical Industry.

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.