Active packaging coatings based on pectin modified with phenolic acids and its application in seabass fillet preservation

In this study, three variants of phenolic acids, namely p-hydroxybenzoic acid (PHBA), p-hydroxyphenylacetic acid (PHAA), and p-hydroxyphenylpropionic acid (PHPA), were integrated into pectin through an enzymatic approach to enhance the preservation efficacy of seabass fillets. Structural elucidation revealed that, under lipase catalysis, each phenolic acid variant was successfully grafted onto pectin via esterification, with the corresponding phenolic acid content being 0.719, 0.699, and 0.731 mmol/g in the p-hydroxyphenylacetic acid-modified pectin (Hb-Pe), p-hydroxyphenylacetic acid-modified pectin (Ha-Pe), and p-hydroxyphenylpropionic acid-modified pectin (Hp-Pe), respectively. Regarding antioxidative activity, the modified pectins showcased a more pronounced inhibition of β-carotene bleaching than their original forms, though there was no noticeable variance in 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging. Additionally, the enhanced pectin displayed increased antibacterial activity against Escherichia coli and Staphylococcus aureus, with the Hp-Pe type presenting the most potent inhibitory effect. Moreover, the application of modified pectin as a coating markedly extended the storage duration of seabass fillets, with the Hp-Pe variant being particularly effective.