EFFECTS OF ESSENTIAL OIL FROM MINT (MENTHA-PIPERITA) ON SALMONELLA-ENTERITIDIS AND LISTERIA-MONOCYTOGENES IN MODEL FOOD SYSTEMS AT 4-DEGREES AND 10-DEGREES-C

The effect of mint (Mentha piperita) essential oil (0.5, 1.0 1.5 and 2 .0%, v/w) on Salmonella enteritidis and Listeria monocytogenes in a cu lture medium and three model foods; tzatziki (pH 4.5), taramosalata (p H 5.0) and pate (pH 6.8), inoculated at 10(7) cfu g(-1), at 4 degrees and 10 degrees C for ca 1 week was studied. In the culture medium supp lemented with the essential oil, no growth was observed over 2 d at 30 degrees C determined by a conductance method with a Malthus 2000 grow th analyser. Salmonella enteritidis died in tzatziki in all treatments and declined in the other foods except for pate at 10 degrees C as ju dged with viable counts. Listeria monocytogenes populations showed a d eclining trend towards the end of the storage period but was increased in pitt. Mint essential oil antibacterial action depended mainly on i ts concentration, food pH, composition, storage temperature and the na ture of the micro-organism.