In vitro Antimicrobial Effect of Probiotic Films Based on Carboxymethyl Cellulose-Sodium Caseinate Against Common Food-Borne Pathogenic Bacteria

Consumption of appropriate amount of probiotic microorganisms via food products have health benefits on the host. In recent years, there has been a significant increase in research on the characterization and verification potential use of probiotic films in food industry. The aim of the current study was to investigate in vitro antimicrobial property of probiotic carboxymethyl cellulose-sodium caseinate (CMC-SC) films containing Lactobacillus acidophilus, L. reuteri and Bifidobacterium bifidum against Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus and Escherichia coli O157:H7. 

Preparation of CMC-SC composite films were conducted based on casting method. The in vitro antibacterial property of CMC-SC films was evaluated using agar disk diffusion and broth micro-dilution methods. 

Antimicrobial property of probiotic films (diameter inhibition zone and log differences in population, respectively) were as follow: S. aureus (2.13-5.65 mm and -0.79 - -3.82) > L. monocytogenes (1.76-5.32 mm and -0.65 - -3.34) > S. typhimurium (2.13-4.33 mm and -0.34 - -2.79) > E. coli O157:H7 (1.88-3.86 mm and -0.18 - -2.62). The best antimicrobial property against aforementioned bacterial pathogens was found for film supplemented with L. acidophilus + L. reuteri + B. bifidum. 

It can be concluded that incorporation of some probiotic strains into edible films resulted in excellent antimicrobial property against S. aureus, L. monocytogenes, S. typhimurium and E. coli O157:H7 and probably solve safety related issue in food industry.