A review on the biological activities of key carotenoids: Structures, sources, market, economical features, and stability

Bioactive compounds present in marine species are abundant, and marine carotenoids in particular have drawn interest due to their potential benefits for health. Because of their unique characteristics, marine carotenoids always have a special appeal among the hundreds of carotenoids that are isolated from various natural biomass. Due to their distinctive colors and various bioactivities, these carotenoids are well known for improving the nutritional content and visual appeal of food products. Consequently, they are essential components in driving the development of the food industry. This review presents the chemistry and classification of all carotenoids and the nutraceutical effects of six widely used carotenoids, lycopene, lutein, astaxanthin, β-carotene, fucoxanthin, and canthaxanthin, on human health. Their production by natural resources such as algae and their various uses in the global market are also discussed. In addition, pioneering companies involved in the production of carotenoids have also been investigated. Furthermore, the stability of valuable pigments can be enhanced by the used techniques in entrapment methods, such as spray drying, supercritical micronization, emulsification, etc. was described. In this regard, the emulsion technique was superior to other techniques owing to its higher availability, safety, and low energy consumption.