Predominance of non-covalent interactions of polyphenols with milk proteins and their health promoting properties.

Polyphenols have widely accepted health benefits which are limited by their low uptake, low bioavailability, and rapid degradation in the gut. While milk proteins are excellent carriers for polyphenols, the specific interactions of the polyphenols with the milk proteins, need to be understood to facilitate the utilization of these delivery systems in food and pharmaceutical applications. We have evaluated the relevance of different factors affecting milk protein-polyphenol interactions and the subsequent impact on the bioavailability and health promoting aspects of polyphenols. Hydrophobic forces are the primary binding forces of polyphenols to milk proteins. The significant factors affecting the interactions and binding affinity are the molecular weight and the hydrophobicity of the polyphenols. The interaction of polyphenols with milk proteins improved the antioxidant activity in comparison to milk proteins, while conflicting results exists for comparisons with polyphenols. In-vitro and cell line studies demonstrated enhanced bioavailability of polyphenols in the presence of milk proteins as well as higher anti-cancer and anti-allergy benefits. Overall, this work will pave the way for better understanding of polyphenol interactions with milk proteins and enable the tailoring of complexes through sustainable green processes, enabling higher bioavailability and health promoting effects of the polyphenols in food and pharmaceutical applications.