Characterization and Antibacterial Activity of Nanochitosan -Nisin Biocomposite Film Prepared from Shrimp Shells

Nanochitosan composite film containing Nisin (NCH-N) was synthesized by solution cast method. Chitosan nanoparticles were prepared from shrimp shell.Characterizations of the prepared chitosan-nanoparticles were performed using Dynamic Light Scattering (DLS) and Fourier Transform Infrared Spectroscopy (FTIR) technique. The DLS analysis showed that the average size of chitosan- nanoparticles was 84.8 nm. Antimicrobial properties of edible (NCH-N) solution were also tested against pathogenic bacteria such as E. coli, P. aeruginosa, S. aureus, B. cereus, L. monocytogenes, E. faecalis, and eight clinical multidrug resistances K. pneumonia and E. coli. Addition of nisin to film significantly enhances the antimicrobial activity of the film against these tested pathogenic bacteria. This solution was also used as an antimicrobial coating on peaches. Based on the results, the peach coated with the film-forming NCH-N solutions presented a significantly lower amount of microorganisms growth than the uncoated peach, and significantly increased the shelf life of peaches. The color of the peach was not influenced by the films. The similarity of peaks in the spectrum of FTIR films confirms the absence of relevant interaction between the nisin and the polymer. The films were also analyzed by Scanning Electron Microscopy (SEM) to investigate the surface topography. Nanohitosan films were smooth and homogeneous. With the addition of nisin to nanochitosan films, the film became more uniform and homogeneous. The incorporation of nisin into edible nanochitosan films or coatings may be an attractive and convenient method for biopreservation of food.