Evaluation of the effect of a sunflower oil-based nanoemulsion with Zataria multiflora Boiss. essential oil on the physicochemical properties of rainbow trout (Oncorhynchus mykiss) fillets during cold storage

- Sunflower oil based nanoemulsion was developed.
- Nanoemulsion had significant effect on Total volatile basic nitrogen.
- Antioxidant effect of the Nanoemulsion was observed.
- We found a decrease in peroxide value and free fatty acids.
- Z. multiflora Boiss. essential oil and the nanoemulsion showed synergistic effect.

The effects of a sunflower oil-based nanoemulsion containing different concentrations of Zataria multiflora Boiss. essential oil (ZMEO, 0.0%, 0.5% and 1%) on the freshness of rainbow trout (Oncorhynchus mykiss) fillets were evaluated by determining the physicochemical and sensory properties during storage at 4 ± 1 °C. The thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), peroxide value (PV), free fatty acids (FFA) and pH were determined on days 0, 5, 10 and 15. The results revealed that the nanoemulsion and ZMEO had synergistic effects on reducing lipid oxidation, as judged by determination of the TBA, FFA and TVB-N, thus extending the shelf life of rainbow trout fillets by at least 15 days.The inhibitory effects of the nanoemulsion were closely related to the concentration of ZMEO due to its high contents of carvacrol and thymol. The quality of fillets treated with the nanoemulsion and 1% ZMEO was significantly different compared with other treatments. Incorporation of ZMEO and the nanoemulsion increased the taste, odour and texture acceptability. Therefore, the nanoemulsion developed in this study could inhibit the development of lipid oxidation during storage at 4 ± 1 °C, representing an option as a food preservative.