Control of psychrotrophic bacteria and Escherichia coli in frescal type fish sausage using oregano essential oil

Abstract

The aim of this work was to prepare frescal fish sausage using oregano essential oil as a preservative. For this, Minimum Inhibitory Concentration (MIC) of oregano essential oil against six food-borne pathogens was determined. The antimicrobial activity of oregano oil (0.08% and 0.16% concentrations) was tested in fish sausage kept under refrigeration, by counting the cultivable psychrotrophic bacteria (CPB) after 20 days and by intentionally inoculation with Escherichia coli (72 h). The oregano essential oil exhibited a strong antibacterial activity (MIC 50-800 μg mL^-1), with bactericidal action (MBC 1600 μg mL^-1). The development of E. coli was inhibited in the frescal fish sausage prepared with 0.08% oregano oil, and the addition of 0.16% oregano essential oil resulted in a better control of CPB. Oregano essential oil can, therefore, be used as an additional barrier against the development of spoilage bacteria and E. coli in food.