Preparation of acylated pectins with phenolic acids through lipase-catalyzed reaction and evaluation of their preservation performance

This study investigated the acylation of pectin with p- coumaric and caffeic acids through an enzymatic method to enhance its physical and chemical properties. Ultraviolet–visible, Fourier transform infrared and 1 H nuclear magnetic resonance spectral analyses indicated the successful grafting of p- coumaric and caffeic acids onto the carboxyl group of pectin molecule. The 1,1-diphenyl-2-picryl hydrazine (DPPH) clearance and inhibition ratio in the β-carotene bleaching assay of native pectin (Na–Pe) were 0.13% and 42.60%, respectively, while their corresponding values increased to 1.04% and 55.59 for the pectin acylated with p -coumaric acid (Co–Pe) and 87.52% and 94.05% for the pectin acylated with caffeic acid (Ca–Pe). Meanwhile, the inhibition of Escherichia coli and Staphylococcus aureus was increased from 2.56% to 6.59% (Na–Pe) to 17.28% and 25.79% (Co–Pe) and 23.59% and 36.94% (Ca–Pe), respectively. Furthermore, Co-Pe or Ca-Pe coating was shown to significantly enhance the shelf life of small yellow croaker ( Larimichthys polyactis ) fillets.