Covalent bonding between polyphenols and proteins: Synthesis of caffeic acid-cysteine and chlorogenic acid-cysteine adducts and their quantification in dairy beverages

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

Protein-polyphenol interactions affect the structure, stability, and functional properties of proteins and polyphenols. Oxidized polyphenols (o-quinones) react rapidly with the sulfhydryl group of cysteine (Cys) residues, inducing covalent bonding between proteins and polyphenols. However, quantitative data on such reactions remain elusive, despite the importance of depicting the significance of such interactions on food structure and function. This work reports the synthesis, purification, and characterization of caffeic acid-cysteine (CA-Cys) and chlorogenic acid-cysteine (CGA-Cys) adducts and their stable isotope analogs, CA-[13C3,15N]Cys and CGA-[13C3,15N]Cys. A sensitive LC-MS/MS isotope dilution method was developed to simultaneously quantify these adducts in foods and beverages. Protein-bound CA-Cys and CGA-Cys were detected in the micro-molar range in milk samples with added CA and CGA, confirming covalent bonding between milk proteins and CA/CGA. These adducts were detected in commercial coffee-containing beverages but not in cocoa-containing drinks. Furthermore, the adducts were found to be partially stable during enzymatic protein hydrolysis.

Details

OriginalspracheEnglisch
Aufsatznummer134406
FachzeitschriftFood chemistry
Jahrgang403
PublikationsstatusVeröffentlicht - 1 März 2023
Peer-Review-StatusJa

Externe IDs

PubMed 36191424
ORCID /0000-0001-8528-6893/work/173053305

Schlagworte

Schlagwörter

  • Michael addition, Milk proteins, Phenolic acids, Polyphenol oxidation, Polyphenol-protein adducts, Protein-phenol interaction