Characterization of resveratrol-milk protein interaction

Resveratrol is a natural polyphenolic compound which is poorly soluble in aqueous solutions. Due to its polyphenolic structure, it possesses antioxidant activity and anticancer effects. Two different milk proteins (β-lactoglobulin (BLG), β-casein (BCN) and bovine serum albumin (BSA)) were used to investigate the influence of protein-resveratrol interaction and its influence on the binding sites, structure and the conformational changes of the proteins. Circular dichroism results showed that resveratrol did not caused any significant change to the secondary structure of proteins. However, steady-state fluorescence results indicated that resveratrol was able to quench the intrinsic fluorescence of the proteins. Fluorescence results were used to calculate the affinity constants between resveratrol and the three proteins. BLG was the protein with the highest accessible fluorophore exposure in comparison with BSA and BNC. In addition, transmission electron microscopy experiments were carried out to visualize the complex resveratrol-protein formation.