Binding of carotenoids to proteins: A review

Carotenoids are lipophilic natural pigments distributed in plants, certain types of algae, fungi and animals. The extensive conjugated double bond system in carotenoids is responsible for their unique color, antioxidant capacity and provide health benefits. However, the hydrophobic nature of carotenoids impacts their color and bioactivity during the development of food products due to their low solubility in aqueous media. The complexation of these molecules with proteins has proven to be an efficient approach for enhancing carotenoid’s solubility and protection against oxidative degradation and hence improving their functional properties and biological activities. This review compiles the molecular interactions between carotenoids and proteins, their physiological relevance, potential applications and characterization of their binding affinities, stabilities, and activities in terms of in-silico analysis and beyond. Overall, the deep understanding and interpretation of binding at the molecular level provide fundamental aspects for the inclusion of carotenoid bioactive compounds in fortified foods and pharmaceuticals.