Antilisterial effect of juniper (Juniperus communis) and its mixed application with winter savory (Satureja montana) in beef protection

Abstract

Juniperus communis essential oil and post-distillation waste were tested for their antibacterial potential against common food contaminants. Results of microdilution assay directed further study of Listeria monocytogenes. Checkerboard assay showed synergistic antilisterial effect of both substances with conventional antibiotics. By evaluating of their cytotoxicity on human colon cells, post-distillation waste was denoted as selective against L. monocytogenes, being able to interfere with its in vitro adhesion on colon cells. On the other hand, the food preservative potential of J. communis essential oil was studied and compared with the activity of Satureja montana essential oil. In a microdilution assay, both substances induced antilisterial effect against reference ATCC 19111 strain and three wild isolates. A checkerboard assay showed synergism against isolates. An in vitro time-kill assay was used to confirm the types of interaction, and to estimate curve MIC values. Finally, in situ antilisterial efficacies of the individual essential oils and their mixture on red wine-marinated beef, previously inoculated with ATCC 19111 strain or primoisolate from beef carcass, were determined. All treatments enhanced the antilisterial potential of wine marinade. In conclusion, derivatives of J. communis possess significant antilisterial potential both in in vitro and in situ conditions, so further research is advised