Abstract
Recently, microalgae have attracted attention as a natural source of healthier bioactive molecules, especially carotenoids, because human bodies lack the ability to synthesize them, and their intake is necessary for human nutrition. Microalgae can produce various classes of these natural products, distinguished by their health benefits. In food sectors, microalgae are available as whole cells or as a source for extracting a specific carotenoid. This review summarizes recent knowledge of the biosynthesis pathway and the factors affecting carotenoid content, as well as strategies for increasing microalgae synthesis of various carotenoids. New uses of carotenoid-rich microalgae in food are highlighted, along with the main challenges and suggested solutions for using microalgal-carotenoids in the foodstuff. Carotenoids, particularly β-carotene and astaxanthin, face significant challenges in terms of bioavailability and stability when included in foods. Although many solutions were proposed, more research is required to determine the stability of other carotenoids under various food processing techniques. Furthermore, future studies should focus on improving bioavailability and accessibility after digestion in order to benefit from all added carotenoids. Modern technology and a fast-paced lifestyle necessitate the inclusion and acceptance of microalgal carotenoids, particularly for the most vulnerable populations, children, and pregnant women.