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This study was designed and conducted to investigate the mechanical and physical properties of fish gelatin films and the effect of Glutaraldehyde crosslinking on antimicrobial control of poly-l-lysine. In this study, the film was prepared by casting method and then 0.05% Glutaraldehyde and 0.05% poly-l-lysine added to fish gelatin film. After that, physical and mechanical properties, antimicrobial activity and release of poly-l-lysine from the film were observed. The results showed that the addition of glutaraldehyde to the fish gelatin film increased tensile pressure (6.80 MPa) and reduced solubility (38.51%), moisture (8.05%), and water vapor permeability (2.03 mm/h mm²kpa×10^-6­). The fish gelatin film with glutaraldehyde as a crosslinking agent was showed a smooth surface without porosity according to the SEM results. Moreover, the release of poly-l-lysine from the biopolymer containing the Glutaraldehyde was slower and more continuous due to crosslinking. Considering the mechanical and physical properties of the films and release control of the antimicrobial compound, it seems that films containing crosslinking agents can be used in food storage.

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Antimicrobial effect of caseinat edible film containing the essential oil of Zataria multiflora Bioss was investigated against tow gram-negative bacteria named Salmonella typhymurium (ATCC14028), Escherichia coli O157:H7 (ATCC35218) and agram-positive bacteria Staphylococcous aureus (PTCC1431). The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the tested essential oil were determinate by using a broth dilution susceptibility test at 6 different concentrations (125, 250, 500, 1000, 2000 and 4000 ppm). The essential oil from Avishan Shirazi( Zataria multiflora Bioss) was most effective against S. aureus, the MIC and MBC values  in the presence of E. coli O157:H7 and S. typhymurium were 500 for both of them. The antimicrobial effect of caseinate film was studing using disk diffusion method. Our result showed that the larger inhibitory diameter was belonged to S. aureus (mean=25.17mm) mean diameters of inhibitory effect for S. typhymurium and E. coli O157:H7 were 15.20 and 17.62 mm respectively.