Effect of Chitosan Coating Nano-emulsion Containing Zataria multiflora and Bunium persicum Essential Oils on Escherichia Coli O157:H7 in Vacuum-packed Rainbow Trout Fillet

Background: Active antimicrobial packaging is a novel method for increasing the safety and shelf life of food products. The present study aimed to investigate the inhibitory effects of chitosan coating nano-emulsion incorporated with Zataria multiflora and Bunium persicum essential oils at the concentrations of 0.5% and 1%, respectively on E. coli O157:H7 in vacuum-packed fish samples during 12 days of refrigeration. Methods: The samples were divided into various groups, including control (no coating), 2% chitosan, 2% chitosan nano-emulsion, and chitosan coating nano-emulsion containing Zataria multiflora and Bunium persicum essential oils at the concentrations of 0.5% and 1%, respectively. The samples were vacuum-packed and stored at refrigeration temperature, and bacterial counting was performed on days zero, one, two, four, six, eight, and 12. Results: The mean bacterial count had a significant difference between the study groups during 12 days of storage (P < 0.001). The most significant inhibitory effect on the growth of E. coli O157:H7 was observed with nano-emulsion of chitosan containing 1% of Bunium persicum. Conclusion: According to the results, using the nano-emulsion of chitosan coating with essential oils could effectively decrease the growth of E. coli O157:H7 in food products, especially fish.in food especially fish.