CHAPTER 8: Carotenoids: Concept, Dietary Sources and Structure–Activity Relationships for Antioxidant and Health-related Properties

Carotenoids are liposoluble pigments naturally found in fruits, vegetables and some animals and microorganisms, with color ranging from yellow to red. The tetraterpene structure of carotenoids with attached chemical groups conjugated with a series of conjugated double bonds is responsible for their ability to absorb light and for their relevant chemical/biochemical reactions, including their in vitro and in vivo antioxidant potential. In terms of physiological relevance, carotenoids are not only known for the provitamin A activity of selected carotenoids, but they also belong to the main class of exogenous compounds with antioxidant properties, and their roles against in vivo oxidative stress and in oxidative-related processes in foods are receiving great attention from the scientific community. In this chapter, carotenoid degradation through reversible and irreversible reactions along with primary and secondary formed compounds are discussed, as well as some food dietary sources, intake of carotenes and xanthophylls and the structure–activity relationships for antioxidant capacity and associated health-related benefits.