Molecular property–affinity relationship of the interaction between dietary polyphenols and bovine milk proteins

Abstract

The relationship between the molecular properties of dietary polyphenols and their affinities for bovine milk proteins (BMP) was investigated. The affinities of polyphenols for BMP were determined by means of fluorescence titration. The affinities of polyphenols for BMP increased with increasing partition coefficient and decreased with increasing hydrogen bond acceptor number of the polyphenol. From this point, the hydrophobic force played an important role in the binding interaction between polyphenols. It was found that the topological polar surface area value decreases with increasing binding constant of the polyphenol for BMP, which illustrates that the glycosylation of hydroxyl groups in polyphenols weakens their binding affinity for BMP. A strong correlation between Mulliken electronegativity and binding affinity was found (R = 0.64626), and Mulliken electronegativity values were found to increase with increasing binding constant of polyphenols for BMP. This illustrates that electrostatic interactions play a key role in binding dietary polyphenols to BMP.