Preparation And Application Of Gelatin-chitosan Composite Film Crosslinked By Genipin

Biological macromolecule based biodegradable packaging is becoming a research hotspot due to increasing environmental pollution.The aim of this paper is to use chitosan nanoparticles(CSNPs)and genipin(Ge)to reinforce gealtin(G)film in order to improve its performance.In addition,the potential application of the composite film in fresh meat storage was investigated in this study.First,G/CSNPs films were fabiricated through mixing gelatin solution with three kinds of chitosan nanoparticles.The results showed that tensile strength of G/CSNPs film was increased while elongation percentage,water vapour permeability and solubility were decreased.The tensile strength of the composite film increased to 37.37 MPa and the water vapor permeability decreased to 1.20 g-mm/(h·m2·KPa)as the particle size of nanoparticles decreased.A good compatibility between gelatin and chitosan nanoparticles was obsearved by scanning electron microscope.FTIR and DSC displayed that there might be a strong interaction between gelatin and chitosan nanoparticles,such as electrostatic attraction or hydrogen bonding,which increased strength,water resistance as well as thermal stability of.the composite film.Secondly,G/CS/Ge films were prepared based on gelatin and chitosan with genipin as a kind of natural crosslinking agent.Tensile strength of composite film increased to 60.29 MPa,water vapour permeability decreased to 1.22 g·mm/(h·m2·KPa)and solubility decreased to 15.02%with the concentration of genipin gradually increased to 0.45%and the increase of molecular weight of chitosan.And the intermolecular interactions between geniping and amino group of gelatin and chitosan,lower weight-loss rate and the compact,uniform structure were discovered.With the concentration of genipin gradually increased from 0.45%to 0.75%,the properties of the composite films were not significantly improved,which demonstrated by scanning electron microscopy,FTIR spectra,TGA curve and cross-linking degree.Finally,this paper discussed G/CSNPs films and G/CS/Ge films applied to fresh meat preservation,and the results indicated that two kinds of composite film can delay the spoilage of fresh meat and better than gealtin film.In addition,there is still a demand for deep research on how to improve the antibacterial properties of the biodegradable composite film as food packaging.