Emerging technologies to improve plant protein functionality with protein-polyphenol interactions

The global demand for plant-based foods has increased interests to new plant-based materials and processing strategies. Plant protein-polyphenol interactions driven by covalent and/or non-covalent bonds are known to impact sensorial, physicochemical, and functional properties of plant-based foods. Emerging processing technologies have potential to enhance plant protein functionality by promoting protein structural changes owing to plant protein-polyphenol interactions. The latest trends in processing technologies for plant protein-polyphenol interactions and the impact on protein functionality are of interest in food industry. This review highlights plant protein-polyphenol interactions induced by physical and chemical processing technologies and the improvement in functionality of plant proteins subject to changes in protein structure. It presents plant protein-polyphenol interactions subject to protein and polyphenol type, the recent development of physicochemical treatments, examples in food applications, and future research directions. The interaction dynamics between plant proteins and polyphenols are contingent on pH levels and processing technologies. Covalent plant protein-polyphenol conjugates could induce a more significant structural rearrangement of proteins than non-covalent interactions, leading to a greater impact on protein functionality. The addition of polyphenols generally augments protein functionality, often leading to a more unordered and unfolded structure of proteins. Physical and chemical treatments including ultrasound, self-assembly, polysaccharide addition, and combined treatments are promising methods to reinforce plant protein-polyphenol interactions and to improve the protein functionality, advancing the quality, safety, and preservation of nutrients. This critical examination of plant protein-polyphenol interactions provides insights into desirable processing technology of plant proteins in food.