Study on antibacterial properties of mucus extract of snakehead (Channa argus) against Escherichia coli and its application in chilled fish fillets preservation

Abstract

The spotlight on natural antimicrobial agents for application in foods is attracting much attention mainly due to their multiple benefits, including non-toxic, good and broad-spectrum antibacterial action. In recent years, various natural active substances have been obtained and identified from fishes due to their unique properties, some of which proved potent for defending against food-borne pathogens. In this study, skin mucus extract (SME) of Channa argus was subjected to efficacy tests against Escherichia coli (E. coli). Its application in chilled fish fillets preservation was further evaluated. The results showed that SME could effectively inhibit the growth of E. coli. Moreover, significant morphological damage and cell mortality rate were observed by scanning electron microscopy and laser scanning confocal microscopy, respectively. Metabolomics analysis revealed that primary metabolic pathways were disturbed under SME stress, resulting in significant metabolite spectra changes. Additionally, SME treatment could extend the shelf-life of chilled fish fillets by approximately 3 days. In conclusion, the present study provided new insights into the bacteriostatic action of SME of C. argus against E. coli and verified the potential value for its application in refrigerated fresh fish fillets preservation.