The β-casein-resveratrol complex: Physicochemical characteristics and implications for enhanced nutrition

Food proteins have been widely used as carrier materials for the encapsulation and protection of bioactive molecules. Clarification the mechanism of protein-bioactive molecule interaction is important for the development protein-based carrier systems. Interaction of b-casein with resveratrol, a natural polyphenol, was studied using ultraviolet-visible absorption and fluorescence spectroscopy. It was found that the interaction shifted the protein fluorophores to a more hydrophilic environment but the polyphenol to a more hydrophobic environment. Formation of the complex with b-casein did not affect trans-cis isomerization of resveratrol or the total antioxidant activity of the protein-polyphenol system, as analyzed respectively using spectrophotometry and 2,2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid assay. The protective effect of resveratrol against the photodecomposition of folic acid was not affected by binding to b-casein. The data obtained should provide insight into protein-polyphenol interaction mechanisms and aid the development of b-casein-based carrier systems for the delivery of bioactive molecules