Laccase-catalyzed grafting of phenolic acids onto pectin: Engineering bioactive films for food preservation.

Abstract

This study employed a green laccase-catalyzed method for phenolic acid grafting onto pectin to prepare sustainable active packaging films. Under mild conditions, p-hydroxybenzoic acid (Pa), 3,4-dihydroxybenzoic acid (Da), and gallic acid (Ga) were successfully grafted onto pectin with grafting rates of approximately 4%. The functionality of phenolic acid-pectin copolymers was significantly enhanced: Ga-Pe achieved DPPH free radical scavenging rate and β-carotene bleaching inhibition rate of 68.20% and 80.97%, respectively (compared to 1.76% and 16.23% for native pectin); antibacterial rates against E. coli and S. aureus were 55.30% and 50.77%, respectively. Pa-Pe contact angle increased from 44.84° to 93.12°, achieving hydrophobic transformation. Shrimp preservation testing showed Ga-Pe treatment reduced bacterial proliferation by 83.33% and maintained superior tissue integrity. This study provides a green enzymatic strategy for developing multifunctional biodegradable packaging materials.