Encapsulated chitosan-moringa oil- based coating for preservation of rainbow trout (Oncorhynchus mykiss) fillets

Abstract Nanotechnology provides effective strategies in food preservation, especially through nanoemulsion-based systems that enhance stability and the controlled delivery of bioactive compounds.The aim of the present study was to investigate the bioactive effect of moringa oil ( Moringa oleifera ) (Mo) encapsulated in a nanoemulsion system containing chitosan (Ch) on the quality parameters of rainbow trout fillets. In line with this objective, characterization studies of Mo and Ch based nanoemulsion (Mo-N), which is known for its high antimicrobial and antioxidant content, were carried out by ultrasonic emulsification method. Than the Oncorhynchus mykiss fillets were coated with this nanoform and monitored for changes in microbiological, chemical and sensory parameters during 12 days of storage. TEM analysis confirmed the regular and spherical morphology of the nanoemulsion; the droplet size of 110.5 nm and PDI value of 0.32 indicated a relatively uniform distribution, suggesting favorable physical characteristics of the system. FT-IR analysis shows that the functional groups of the key components are retained after high-energy treatment. The findings revealed that Mo-N treatment effectively suppressed and delayed bacterial growth and had a positive effect on consumer acceptance. In addition, Mo-N minimized lipid and protein oxidation and discoloration of fillets and preserved the sensory parameters of fillets during storage compared to the control sample. According to the shelf life assessment, the developed Mo-N coating proved to be effective in preserving the quality characteristics of rainbow trout fillets, thus extending the shelf life by at least 3 days.