Advances in protein–polyphenol complexation: Unraveling mechanisms, modulation, and functional outcomes

Abstract Polyphenolic compounds have attracted increasing market demand and extensive attention due to their potential health benefits and bioactivities. Meanwhile, proteins are widely used in the food industry for their nutritional and functional properties. However, the application of proteins in the food industry is often limited by challenges, such as their tendency, to induce allergic reactions and poor emulsifying properties. During food processing and human digestion, proteins readily form complexes with polyphenolic compounds. The interactions enhance the stability, bioactivity, functional properties of polyphenols, and change the conformational structure of proteins, thereby reducing their allergenicity and improving their functional characteristics such as solubility, emulsifying capacity, and emulsion stability. Based on this, this review initially outlines the basic properties of proteins and polyphenolic compounds as well as the research progress on their binary complexes. Subsequently, the interaction mechanisms between polyphenols and proteins and the influencing factors were explored. Finally, it systematically summarizes the effects of these interactions on the structure and functional characteristics of protein–polyphenol complexes. This review focuses on polyphenol–protein complexes aiming to advance their applications in functional food development and food nanocarriers. The findings seeks to provide a theoretical foundation and practical guidance for future food processing technologies.