Investigation of the effect of essential oil along with nanocoatings containing gums in the development of fish fillet storage time

Abstract

In this study, the antioxidant activity of Bunium persicum essential oil (EO) at different concentrations of 1%, 1.5%, and 2% (W/V) was evaluated. Also, antibacterial effect of three types of nano-coatings, i.e., basil seed gum (BSG), Lepidium perfoliatum seed gum (LPSG), and their combination (1:1 ratio), was examined for extending the shelf life of rainbow trout (Oncorhynchus mykiss) fillets for 16 days at 4 °C. The amount of phenolic compounds for Bunium persicum was 133.81 ± 2.74 mg/g. The antioxidant activity of EO was assessed by two methods of DPPH and beta-carotene at different concentrations (200, 400, 600, 800, and 1000 mg/L). The size of the prepared nano-coatings ranged from 265.17 to 454.66 nm and the zeta potential was negative for all of them. In order to study the effect of nanocomposite coating on the shelf life, 10 treatments including control, BSG, LPSG, and their combination with EO (at 1, 1.5, and 2%) were prepared and peroxide value, thiobarbituric acid, as well as pH, total volatile nitrogen, total viable count, total psychrotrophic count were measured in 4-day intervals. The results showed that the nano-coatings containing EO had antioxidant and antimicrobial properties and were able to improve the above-mentioned properties. The data obtained from this study revealed that the nano-coatings containing EO could delay the oxidation process and microbial spoilage of the treatments (p < 0.05); by increasing the concentration of EO, better results were observed. According to the results, BSG-LPSG containing 2% EO can be used as a proper substitute for artificial and chemical food preservatives.