A multi-spectroscopic study on the interaction of food polyphenols with a bioactive gluten peptide: From chemistry to biological implications

•Polyphenol-peptide binding occurs through an entropy-driven hydrophobic effect.•Polyphenol-peptide binding depends on polyphenol substitution pattern and polymerization.•Polyphenols bound to 32-mer Tyr, Leu and Phe containing domains.•Procyanidins B3 and C2 reduced the 32-mer transepithelial translocation in vitro.•In addition to peptide binding, other regulatory mechanisms are involved.