en علوم پایه پزشکی Basic Medical Sciences تحقیقی Original article <p style="text-align: justify;"><span style="font-size:14px;"><span style="line-height:150%"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Background and Objectives:</span></span></i></b><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""> 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 <i>Escherichia coli </i>O157:H7 inoculated in rainbow trout fillet over 12 days at 4 ˚C was examined. <b><i></i></b></span></span></span></span><br> <span style="line-height:150%"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Material and Methods:</span></span></i></b><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""> Fish samples were allocated into six groups following inoculation with <i>E. coli</i> O₁₅₇:H₇ (final concentration: ~ 10⁵ CFU/g). Treatments included control (CON), distilled water (DW), neutral electrolyzed water (NEW), chitosan 2% (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 0, 1^st, 3^rd, 6^th, 9^th, and 12^th days. Data analyses were done through repeated measure ANVOA and Bonferroni post hoc tests. </span></span></span></span><br> <span style="line-height:150%"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Results: </span></span></i></b><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">As indicated by the findings, the reduction rate of EW, CH, CH+WE, and CH/EW samples were 1.04, 1.45, 2.01, and 2.02 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. <b><i></i></b></span></span></span></span><br> <span style="line-height:150%"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Conclusion:</span></span></i></b><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""> Chitosan coating can be combined with NEW in fish to increase the safety against pathogenic bacteria and <i>E. coli </i>O₁₅₇:H₇. Therefore, it can suggest the use of these natural antimicrobial compounds in the food industry.</span></span><span style="line-height:150%"><span style="font-family:"Times New Roman","serif""></span></span></span></span></span><br> <br> <span style="line-height:115%"><span sans-serif="" style="font-family:Calibri,"><span style="line-height:115%"><span style="font-family:"Times New Roman","serif""></span></span></span></span></p> Food Preservation,Escherichia coli O157,Oncorhynchus mykiss,Chitosan,Food Safety, 26 34 http://goums.ac.ir/jorjanijournal/browse.php?a_code=A-10-896-1&slc_lang=en&sid=1 Fatemeh Mohajer 10031947532846008331 10031947532846008331 No Department of Food Hygiene and Aquaculture, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Saeid Khanzadi khanzadi@um.ac.ir 10031947532846008332 000000030106587X Yes Department of Food Hygiene and Aquaculture, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Mohammad Hashemi 10031947532846008333 3: 0000-0001-9998-6727 No Medical Toxicology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran/ Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Mohammad Azizzadeh 10031947532846008334 4:0000-0001-9192-5022 No Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran