Lutein and Zeaxanthin: Source, Extraction, Stability, Bioactivity, and Functional Food Applications

Nature has been acknowledged as a fundamental source of diverse bioactive molecules. Among natural carotenoids, lutein, zeaxanthin, and their oxidative metabolites are specifically deposited in the macular region of living organisms. Lutein and zeaxanthin are carotenoids primarily found in green leafy vegetables, eggs, and various fruits. Lutein and zeaxanthin emerge as the primary carotenoids in the retina, playing a crucial role as photo-protectants to prevent retinal degeneration. The extraction of lutein and zeaxanthin from natural sources involves several techniques, including solvent extraction and supercritical fluid extraction, with an emphasis on optimizing efficiency and yield. Incorporating these carotenoids into functional foods—such as fortified dairy products, baked goods, and snacks—enhances their nutritional profiles and provides significant health benefits. This review examines the sources, stability, bioactivity, and various extraction methods for lutein and zeaxanthin, highlighting their potential for photoprotection, antioxidant activity, and antidiabetic effects. These attributes, combined with innovative extraction techniques, position lutein and zeaxanthin as promising ingredients for functional food applications.