Effect of black cumin (Bunium persicum) essential oil encapsulated with basil seed gum (Ocimum basilicum L.) on chemical, microbial and sensory changes of rainbow fillet during refrigerated storage

In this study, the antioxidant and antimicrobial effect of nano coating of basil gum with black cumin essential oil (Bunium persicum) was investigated in order to increase the shelf life of rainbow trout fillets. For this purpose, black cumin essential oil was prepared using Clevenger device and the antioxidant activity of different concentrations of it (200, 400, 600, 800 and 1000 ppm) was investigated. According to the results, black cumin essential oil has high antioxidant properties, and as the concentration increased, antioxidant properties were increased too. The cumin essential oil was then nanocapsulated with a basil gum coating. The nano coating, along with the essential oil (according to the electron microscope image), had a spherical and uniform surface with a low porosity percentage. Then, in order to investigate the effect of nano-coating with essential oil on the shelf life of rainbow trout fillet during a 16-day refrigeration period, 4 treatments including control and nano-coating with different concentrations of black cumin essential oil (1, 1.5 and 2 %) produced and periodic chemical parameters (peroxide, thiobarbiotic acid and volatile nitrogen bases) and microbial (total bacterial and total psychrotrophic count) were studied. The results of chemical and microbial analysis showed that, the nano-coating along with the essential oil slowed down the increasing process of oxidation and microbial indices compared to the control treatment. Until the end of the storage period, they had the allowed chemical and microbial range. Therefore, it seems that this treatment can be used as a natural antioxidant and antimicrobial in the meat and fisheries industry.