Exploring non-covalent interactions of β-casein with six polyphenols.

β-casein is a promising delivery agent for polyphenols that protect their bioactivity. However, limited evidence has been reported on their optimal combination ratios of polyphenols with β-casein and elucidated the factors affecting their interactions. Herein, correlation analysis was used to study the impact of structural, physical, and chemical properties of six polyphenols that are found in abundance in fruits, on their interactions with β-casein, following multi-spectroscopy analysis of optimal molar concentration ratio evaluation. Quenching efficiency was primarily positively influenced by polyphenol molecular weight to its number of hydroxyl groups ratio. Interactions of flavonoids with β-casein were positively affected by their hydrophobicity, whereas phenolic acids were negatively correlated to their charge. The optimal polyphenol to β-casein molar ratio was at or below 20:40. Our findings contribute to an enhanced comprehension of the mechanisms governing milk protein-polyphenol interactions, facilitating the cost-effective applications of polyphenols across food and pharmaceutic industries.