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

Abstract

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 1H 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.