Effect of <i>Ocimum basiicum</i> L. essential oil microemulsion on the quality of snakehead (<i>Channa argus</i>) under different dipping conditions during cold storage

Abstract Background Ocimum basiicum L. essential oil (OBEO) is an herbal essential oil that inhibits microbial activity during food preservation. However, preservation of aquatic products is susceptible to environmental factors. The efficacy of different impregnation techniques was evaluated. In this study, we investigated the application of OBEO in the cold storage process of snakehead fish fillets. Results In terms of microbiological and ammonia content, the best freshness of snakehead fillets was observed under normal impregnation. On the 18th day, the essential oil impregnated group without ultrasonic and vacuum treatment showed a reduction in trimethylamine content by 5.14 mg/100 g, total volatile base nitrogen by 16.32 mg N/100 g, K value by 50.82%, and H 2 S content by 134.73 mmol/g, as compared to the control group. Similarly, the indexes such as the pH value, free amino acid (FAA) value and ammonia content reflected the bacteriostatic properties of OBEO and the degree of spoilage of snakeheads. In a word, the results showed that although the homogeneity of the emulsion was improved after ultrasonic treatment, it tends to destabilize the snakehead fillets. Conclusion Therefore, this study demonstrated that snakehead fillets exhibited better preservation under normal or vacuum conditions in combination with OBEO impregnation.