Interactions between polyphenol oxidation products and salivary proteins: Specific affinity of CQA dehydrodimers with cystatins and P-B peptide

Throughout the apple juice and cider making process, polyphenols undergo enzymatic oxidation which generates a great variety of polyphenol products. Since 5?-O-Caffeoylquinic acid (CQA) is one major phenolic compounds preferential substrate for polyphenoloxidase in juice, its leads to formation newly formed molecules by dehydrodimers (MW 706 Da) are included. Interactions salivary proteins (SP) with native well-known phenomenon, but their interactions products has not been studied yet. In this work, we decided decipher between CQA SP (gPRPs, aPRPs, statherins/P-B peptide, cystatins) using HPLC-UV fluorescence. These results showed that contrary what was expected, presented low interaction PRPs, revealed specific peptide cystatins. This work settles first time