Insights into interactions between polyphenols and proteins and their applications: An updated overview

Polyphenols, as critical secondary metabolites in nature, are widely distributed in vegetables, fruits, grains, and other foods. Polyphenols have attracted widespread attention in the fields of food industry and nutrition due to their unique structure and various biological activities (antioxidant, anti-inflammatory, anti-tumor, hypoglycemic, immunological activities, etc). However, their application in food systems are limited due to their chemical instability and sensitivity to environmental factors. The interaction between polyphenols and proteins largely determines the stability and functional characteristics of polyphenols in food processing and storage. Hence, this topic has attracted widespread attention in recent years. This article systematically reviews the interaction modes between polyphenols and proteins. Moreover, the review comprehensively summarizes the characterization methods including ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), isothermal titration calorimetry (ITC), nuclear magnetic resonance (NMR), and molecular docking techniques for their interactions. Furthermore, this paper systematically outlines the effects of the interaction between polyphenols and proteins on their physicochemical and functional properties, and introduces the application of the polyphenol-protein complexes. The findings can provide important references for in-depth exploration of the interaction between polyphenols and proteins in the field of food. • Polyphenols bind to proteins through covalent and non-covalent interactions. • The interaction between polyphenol and protein is characterized by different methods. • The interaction between polyphenol and protein alters the their properties.