Antimicrobial Effect of Chitosan Coating Prepared by Neutral Electrolyzed Water against Inoculated Escherichia coli O۱۵۷:H۷ on Rainbow trout fillets

Background and Objectives: Nowadays, to avoid the use of synthetic preservatives, which do more harm than good, numerous studies are currently focused on using natural ingredients to enhance food product quality and shelf life. Since no study has been conducted on combining coatings with electrolyzed water containing natural antimicrobial compounds, the present study has innovation and priority. In the present study, the effect of chitosan coating prepared through Neutral Electrolyzed Water (NEW) on inhibiting the growth of Escherichia coli O۱۵۷:H۷ inoculated in rainbow trout fillet over ۱۲ days at ۴ ˚C was examined. Material and Methods: Fish samples were allocated into six groups following inoculation with E. coli O۱۵۷:H۷ (final concentration: ~ ۱۰۵ CFU/g). Treatments included control (CON), distilled water (DW), neutral electrolyzed water (NEW), chitosan ۲% (CH), chitosan coating prepared by neutral electrolyzed water (CH/NEW), and neutral electrolyzed water followed by chitosan (NEW+CH). Treatments were kept at low temperature (refrigerator) and counting bacteria was done on ۰, ۱st, ۳rd, ۶th, ۹th, and ۱۲th days. Data analyses were done through repeated measure ANVOA and Bonferroni post hoc tests. Results: As indicated by the findings, the reduction rate of EW, CH, CH+WE, and CH/EW samples were ۱.۰۴, ۱.۴۵, ۲.۰۱, and ۲.۰۲ log CFU/g compared with the CON, respectively. The highest reduction rate was observed in the CH/NEW sample, due to the antimicrobial activity of chitosan and neutral electrolyzed water. Conclusion: Chitosan coating can be combined with NEW in fish to increase the safety against pathogenic bacteria and E. coli O۱۵۷:H۷. Therefore, it can suggest the use of these natural antimicrobial compounds in the food industry.

Keywords:

Food Preservation , Escherichia coli O۱۵۷ , Oncorhynchus mykiss , Chitosan , Food Safety