Advances in Sustainable Lutein Production: Sources, Technologies, and Functional Applications

Lutein is a xanthophyll carotenoid widely recognized for its roles in eye health, antioxidant and neuroprotective effects, and the prevention of oxidative stress-related disorders. The growing demand for functional foods and nutraceuticals has heightened industry interest in sustainable lutein production. However, conventional sources such as green vegetables and marigold flowers face several limitations, including low bioavailability, seasonal variability, land-intensive cultivation, and sustainability concerns. Therefore, this review provides an updated, comprehensive, and integrated overview of sustainable lutein production, extraction technologies, and functional applications. This review discusses conventional dietary sources alongside emerging alternative platforms, including microalgae, agro-industrial byproducts, and bioengineered fermentation systems. Recent advances in green extraction technologies, particularly supercritical CO2, ultrasound-assisted, and enzyme-assisted extraction, are also critically evaluated due to their potential to improve extraction efficiency while reducing environmental impact. In addition, the applications of lutein in functional foods, nutraceuticals, and pharmaceutical products are also highlighted. This review further examines key technical challenges, including low bioavailability, high production and downstream processing costs, compound instability, extraction inefficiencies, lack of standardization, and scalability limitations. Future progress will depend on integrating circular bioeconomy strategies, artificial intelligence (AI)-assisted process optimization, sustainable biorefinery concepts, and advanced stabilization technologies to support economically viable and environmentally sustainable lutein production systems.