Study On Preparation And Properties Of Linalool/Chitosan Quaternary Ammonium Salt/Fish Gelatin Emulsified Antibacterial Films

In this thesis,chitosan quaternary ammonium salt/fish gelatin antibacterial films and linalool/chitosan quaternary ammonium salt/fish gelatin emulsified antibacterial films were prepared using fish gelatin as film-forming matrix,chitosan quaternary ammonium salt and linalool as antibacterial agents.Based on the study of its antibacterial properties,the mechanical properties,moisture resistance and thermal stability of the antibacterial film were explored.By means of the microstructure of the films,we also investigated the relationship between microstructure and properties of films.And we will provide the theoretical basis and experimental data for industrial application.The main research contents are as follows:Firstly,chitosan quaternary ammonium salt/fish gelatin antibacterial films were prepared by using chitosan quaternary ammonium salt and fish gelatin as raw materials.It is found that chitosan quaternary ammonium salt can not only impart good antibacterial property of fish gelatin films,but also can improve the ductility and thermal stability of fish gelatin films effectively.The multi-function of the films will be realized,which has laid a good foundation for its practical application.Secondly,linalool/chitosan quaternary ammonium salt/fish gelatin emulsified antibacterial films were prepared based on the difference of antibacterial mechanism of chitosan quaternary ammonium salt and linalool.When the concentration of linalool was 1.2 wt%,the elongation at break of the as-prepared films increased up to 61.7%and the tensile strength was still up to 37.8 MPa.At the same time,moisture resistance of the as-prepared films was increased up to 39.3%.When the concentration of linalool was 0.8 wt%,the water contact angle increased from 57.0° to 81.5°.The results showed that linalool not only enhanced the antibacterial activity of the as-prepared films,but also increased the elongation at break,light resistance,moisture resistance and water resistance of the as-prepared films,which will be beneficial to the practical application of emulsified antibacterial films.Thirdly,the antibacterial kinetics of chitosan quaternary ammonium salt and linalool was tested by microplate method.It was found that the inhibitory effect of chitosan quaternary ammonium salt and linalool on S.aureus and E.coli were concentration-dependent manner and time-dependent manner,and the inhibition rate of E.coli was 89.8%when the ratio of chitosan quaternary ammonium salt and linalool was 3:5,it were significantly greater than the single component of both.It was proved that chitosan quaternary ammonium salt and linalool had synergistic antibacterial effect.