Preparation and characterization of grass carp collagen-chitosan-lemon essential oil composite films for application as food packaging.

Encapsulation effectively delays the volatilization of lemon essential oil (LEO). Here, various chitosan (CS)-LEO nanoparticles were prepared by emulsification using different CS and Tween-80 concentrations and CS:TPP and CS:LEO ratios. The CS-LEO nanoparticles were spherical, small in size (58 ± 9 nm), had a low polydispersity index (0.15), and were highly stable under the right conditions. FTIR spectra indicated that they were fully encapsulated in the films. The composite films are characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscope (SEM) and X-ray diffraction (XRD). Relative to grass carp collagen (GCC) films, edible GCC/CS-LEO had lower oxygen permeability (OP), higher tensile strength (TS), and higher elongation at break (EB). The LEO release rate increased with decreasing GCC:CS-LEO ratio. At GCC:CS-LEO ratio = 7:3, a maximum LEO release rate of 83.6 ± 9.7% was achieved over 15 days. GCC/CS-LEO films can effectively inhibit lipid oxidation, prevent microbial proliferation, and delay the deterioration of pork at 4 °C for 21 days.