engleski

Antibacterial effect of natural bioprotective agent enterocin EF-101 in meat

Bacteriocins are bacterial ribosomal peptides that exhibit antimicrobial activity. Their use in food can affect bacterial foodborne pathogens and spoilage bacteria. In this work, the antibacterial effect of enterocin EF-101 was investigated in minced meat packed in aerobic conditions and cold-stored during the shelf life. Enterocin was semi-purified from the neutralised supernatant (pH = 7 ; 10 N NaOH) of Enterococcus faecalis EF-101 culture by ammonium sulphate precipitation (484.54 g/L). The activity of enterocin (AU/mL) was tested against Listeria monocytogenes NCTC 10527 and the appropriate solution of enterocin in phosphate buffer (pH = 7) was added to minced meat (2560 AU/kg). Minced meat with and without enterocin was microbiologically analysed on days 0, 1, 2, 3 and 4 in triplicate for the aerobic mesophilic bacteria count, enterobacteria, psychrophiles, staphylococci, coliforms, Escherichia coli, lactic acid bacteria, L monocytogenes and pH values. The number of aerobic mesophilic bacteria, enterobacteria, psychrophiles, staphylococci, coliforms and lactic acid bacteria was expected to increase during storage period in both groups of samples, while pH was not significantly changed. However, the antimicrobial effect of enterocin may be the reason for 0.5 and 1.2 logs lower population of lactic acid bacteria and enterobacteria at the end of storage period, respectively. Still, the strongest antimicrobial effect was noted on day 0 or immediately after the addition of enterocin to the population of psychrophiles, coliforms, staphylococci and aerobic mesophilic bacteria. The obtained results indicate the activity of enterocin in the meat substrate, but with a limited antimicrobial effect probably due to its rapid degradation by tissue enzymes. It is necessary to further evaluate the stability and activity of enterocin EF-101 in combination with other antimicrobial technologies.

enterocin, meat, microbiota

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