en Food Safety and Hygiene Food Safety and Hygiene پژوهشي Original Article <div style="text-align: justify;"><span style="line-height:1;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><b>Background</b><strong>:</strong> Rainbow trout (<i>Oncorhynchus mykiss</i>) is widely consumed due to its nutritional value; however, it remains highly perishable. In this study, we investigated the effects of an edible coating derived from <i>Vicia villosa</i> protein isolate (VVPI) combined with zinc oxide nanoparticles (ZnO NPs) to prolong the shelf life of rainbow trout fillets under refrigerated conditions (4 &plusmn; 1 &deg;C).<br> <b>Methods:</b> VVPI was extracted from defatted <i>Vicia villosa</i> seeds, and three coating formulations were prepared: VVPI alone, VVPI with10 mg ZnO/100 mL, and VVPI with 20 mg ZnO/100 mL. Rainbow trout fillets were coated and monitored for 12 days. Various chemical indices including pH, free fatty acids, peroxide value, thiobarbituric acid-reactive substances, and total volatile nitrogen along with microbial loads, and sensory attributes were evaluated on Days 0, 4, 8, and 12.<br> <b>Results:</b> The results showed that fillets coated with VVPI-containing ZnO NPs had significantly lower levels of lipid oxidation and microbial growth than the control and VVPI-only samples. Higher concentrations of ZnO NPs (20 mg/100 mL) exhibited the strongest protective effect, delaying the onset of rancidity and maintaining sensory quality. The shelf life of the fillets was effectively extended by four days, highlighting the potential of this approach to preserve fish fillets.<br> <b>Conclusion</b><strong>:</strong> Incorporating ZnO NPs into VVPI-based coatings presents a promising strategy for enhancing the freshness and acceptability of rainbow trout fillets<font color="#000000">.</font></span></span></span></div> Nanocoating, Vicia villosa, Zinc oxide, Rainbow trout, Shelf life, 77 87 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-663-1&slc_lang=en&sid=1 Bahar Lotfi bahar.ltfm@gmail.com 100319475328460015643 100319475328460015643 No Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran. Sara Mehdizadeh Mood smehdizadeh@semnan.ac.ir 100319475328460015644 100319475328460015644 Yes Department of Food Hygiene and Aquatic Animal, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran. Ashkan Jebeli Javan jebellija@semnan.ac.ir 100319475328460015645 100319475328460015645 No Department of Food Hygiene and Aquatic Animal, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran. Behdad Shokrollahi Yancheshmeh behdad.shokrollahi@gmail.com 100319475328460015646 100319475328460015646 No Research Group for Food Production Engineering, National Food Institute, Technical University of Denmark, kgs. Lyngby, Denmark.