pH-Shifting-Mediated Coassembly with Polyphenols Reduces Allergenicity and Maintains Functionality of Peanut Protein

Developing effective strategies to reduce peanut protein allergenicity while preserving functionality remains a challenge. This study investigated the pH-shifting-mediated coassembly of peanut protein with quercetin and rutin through spectroscopic and thermodynamic analyses for structural characterization, in vitro digestion, and BMDC-based assays for allergenicity assessment, along with functional analyses. The pH-shifting treatment significantly enhanced the polyphenol binding efficiency, concurrently inducing protein unfolding and the formation of soluble aggregates, thereby reducing surface hydrophobicity and altering the secondary structure. Coassembled complexes exhibited markedly lower IgE-binding and slower gastric digestibility than native or direct-mixed complexes. Immunologically, pH-shifted complexes better inhibited BMDC uptake, down-regulated maturation markers (MHC-II, CD40, CD80, and CD86), promoted a tolerogenic phenotype, and redirected T-cell responses from Th2/Th17 toward Th1/Treg. Functionally, the treatment enhanced foaming capacity but variably affected water-holding capacity, and foam stability may depend on polyphenol structure. Therefore, this study offers a novel strategy for designing hypoallergenic and functional peanut protein ingredients.