Effect of electrolyzed water and chitosan coating incorporated with thymol and carvacrol on inoculation of Escherichia coli O157H7, Pseudomonas aeruginosa, Listeria monocytogenes, in rainbow trout fillet

Abstract

Background and objectives: The objective of the present study was to assess the effects of electrolyzed water and chitosan coating incorporated with thymol and carvacrol, on the inoculation of Escherichia coli O157:H7, Pseudomonas aeruginosa, and Listeria monocytogenes in rainbow trout fillets. This assessment was conducted during cold storage on days 0, 1, 3, 6, 9, and 12. Furthermore, the antimicrobial effectiveness of thymol and carvacrol was assessed against the designated bacteria through the determination of their minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). Results: The MIC and MBCvalues for both thymol and carvacrol exhibited uniformity among all strains. Relative to the control samples, the chitosan coatings produced using electrolyzed water containing either thymol or carvacrol (EW/CH/THY and EW/CH/CAR) exhibited the most significant reduction in Listeria monocytogenes (approximately 3 log10 CFU/g), Pseudomonas aeruginosa (around 3 log10 CFU/g), and Escherichia coli O157:H7 (about 2 log10 CFU/g). Furthermore, when chitosan or electrolyzed water was used individually, a decrease of approximately 1 log10 CFU/g in bacterial growth was observed compared to the control samples. Additionally, on day 0, a reduction rate of 1–3 log10 CFU/g in bacterial growth was recorded when compared to the control. Conclusions: The study suggests that a combination of chitosan, electrolyzed water, and essential oils can provide protection against pathogenic bacteria in food products. The findings highlight the possibility of utilizing chitosan coating as a feasible and secure substitute for artificial preservatives.

Keywords

• Food safety
• Antimicrobial agents
• Pathogenic bacteria