Enhancing Carotenoids’ Efficacy by Using Chitosan-Based Delivery Systems

Carotenoids represent a large group of well-known substances, mainly due to their nature as pigments and their beneficial effects on human health. These compounds are found naturally in microorganisms and plants but are not produced by humans, who must consume them through their diet. However, the mere intake of foods containing even large quantities of carotenoids is insufficient to guarantee their optimum absorption and, therefore, the desired beneficial effects. Due to their physicochemical characteristics, carotenoids are poorly stable and mostly insoluble in polar solvents like water. The conservation and improvement of their properties have become crucial objectives for the nutraceutical and functional food sector. Increasingly innovative delivery systems are being tested and developed. In this context, chitosan, a polysaccharide derived from the deacetylation of chitin, available in the exoskeleton of crustaceans and insects and the cell wall of some fungi and marine microalgae, has proved to be highly advantageous. In this review, we summarize the main characteristics of carotenoids, their benefits on human health, and their bioaccessibility and bioavailability for humans. We analyze the most recent carotenoid delivery systems, focusing on the potential of chitosan in preserving and enhancing the beneficial effects of these valuable pigments.