Carotenoids and Their Antioxidant Power

Abstract

Carotenoids are natural products found in photosynthetic organisms such as plants, algae, and some bacteria species. Humans and animals cannot synthesize carotenoids, and they obtain these molecules through their diet. The common structure of carotenoids contains conjugated double bonds that provide color formation in the visible spectrum, at 400–500 nm. In photosynthetic organisms, carotenoids contribute to color formation for various purposes, such as sex selection, protection from predators, and light-harvesting to increase the spectral range of photosynthesis. The conjugated double bonds not only provide color formation but also provide antioxidant properties to carotenoid molecules. Studies have shown that carotenoids are capable of scavenging free radicals and reactive oxygen species, as well as quenching singlet oxygen molecules. The antioxidant power of carotenoids results in several health benefits. These include anticancer, neuroprotective, and anti-atherosclerotic activities. This chapter aims to review the antioxidant activities and health benefits of major carotenoids, beginning with their structure and synthesis, and also discussing their natural sources.