Development and characterization of an LDPE/chitosan composite antimicrobial film for chilled fish storage

An antimicrobial packaging material was developed by uniformly embedding 1, 3 and 5% chitosan (w/w) in low density polyethylene matrix using maleic anhydride grafted LDPE as a compatible agent. The materials were mixed by compounding and blown into monolayer films via blown film extrusion. The developed films showed good barrier properties against oxygen. Characterization of the composite films with Fourier transform infrared spectroscopy revealed that chitosan and LDPE interacted well with each other. Overall migration showed better release of chitosan adduct from the LDPE matrix which enhanced the antibacterial properties of the films. The interaction between the LDPE/CS and maleic anhydride grafted LDPE had a decreasing effect on the tensile strength and heat sealing properties. Investigation on antimicrobial properties of LDPE/CS films showed 85-100% inhibition of Escherichia coli. Efficacy of LDPE/CS films was evaluated by using them as packaging material for chilled storage of Tilapia (Oreochromis mossambicus). Analysis of storage quality indices (peroxide value, free fatty acid, total volatile base nitrogen and aerobic plate count) revealed good antibacterial property and extension of shelf life of Tilapia in the chitosan incorporated novel composite films compared to virgin LDPE film.