Molecular interactions between 3,4-dihydroxyphenylglycol and pectin and antioxidant capacity of this complex in vitro

Abstract

This study explored the interaction of pectin with 3,4-dihydroxyphenylglycol (DHPG), a potent phenolic antioxidant naturally found in olive fruit, via encapsulation into pectinate beads. MALDI TOF-TOF analysis supported the formation of complexes between DHPG and pectin. A combination of covalent bonds (ester bonds) and non-covalent interactions, mostly hydrogen bonding, were suggested as the cause of DHPG-pectin complex formation. Free radical scavenging assays confirmed that DHPG maintained its antioxidant activity after complexation and after a digestion simulated in vitro with gastric and intestinal fluids. Therefore, DHPG-pectin beads could reach the large intestine and contribute to a healthy antioxidant environment.

Keywords: 3,4-Dihydroxyphenylglycol; Antioxidant; Covalent binding; MALDI TOF-TOF MS; No-covalent binding; Phenol-pectin complex.