The Effect of Sodium Caseinate Films Incorporated with Lactobacillus. acidophilus and Lactobacillus. casei Bacteria to Control Listeria monocytogenes Inoculated Silver Carp (Hypophthalmichthys molitrix) Fillet

Casein-based edible films due to high nutritional value have potential to protect the food products. The purpose of this investigation is to prepare sodium caseinate film containing Lactobacillus acidophilus and Lactobacillus casei and determine the antibacterial activity of the film against Listeria monocytogenes inoculated into the silver carp fillet.
In this survey, Lactobacillus acidophilus and Lactobacillus casei bacteria in the form of solution were added to sodium caseinate film and dried at 40°C for 24 hours. The effect of the film to control Listeria monocytogenes was determined on silver carp fillets and culture media during 9 days at 96 hour intervals. The viability of the LAB bacteria within 12 days in culture medium and fish fillet were studied at 96 hours intervals. The effects of incorporated bacteria on the physical and mechanical properties of the film were also examined.
The viability of lactic acid bacteria in fillets was increased. Both bacteria caused reduction in the Listeria count as compared to the control group. Lactic acid bacteria had a significant effect on the solubility percentage, moisture, L index and color difference, however there were not significant differences in tensile strength and elongation percentage.
Due to a significant decrease in L. monocytogenes viable count on culture media, it seems that the incorporation of LAB cells into films could be a useful method to control food pathogens.