Biopreservative activity of tarragon essential oil against Escherichia coli and Staphylococcus aureus in salmon samples

Given the growing consumption of fish and the “clean label” trend in food production, there is an urgent need to develop effective/alternative methods for extending shelf life and ensuring seafood safety. This study aimed to evaluate the antimicrobial effect of tarragon essential oil (EO) against foodborne Escherichia coli and Staphylococcus aureus strains. The examined oil at a selected concentration (100 nL mL − 1 ) did not reduce MTT-based metabolic activity in human normal intestinal CCD 841 CoN cells. The exposure of E. coli to the tested oil increased the abundance of selected unsaturated fatty acids, including C18:1, trans 9 and C18:1, cis 9 in comparison to those in the control E. coli culture. S. aureus responded to the toxic stress of exposure to tarragon EO, as it mostly overproduced C14:0 and decreased the abundance of iso-C15:0, anteiso-C15:0, C16:0, C18:0 and C15:0 in the cell membrane. In this study, tarragon EO inhibited the expression of type II fatty acid synthase system-related genes in the E. coli and S. aureus strains; however, the greatest inhibition was observed for the fabA and fabD genes of E. coli (0.35 and 0.47, respectively) and for the fabG gene of S. aureus (0.35). In situ experiments confirmed the oil’s antimicrobial/biopreservative effects against E. coli and S. aureus strains inoculated into salmon. Sensory evaluations showed that the shelf life of the salmon-based product can be up to 5 days.