The antimicrobial activity of essential oils of oregano, thyme, basil, marjoram, lemongrass, ginger, and clove was
investigated in vitro by agar dilution method and minimal inhibitory concentration (MIC) determination against
Gram-positive (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative strains (Escherichia coli and
Salmonella Enteritidis). MIC90% values were tested against bacterial strains inoculated experimentally in irradiated
minced meat and against natural microbiota (aerobic or facultative, mesophilic, and psychrotrophic bacteria)
found in minced meat samples. MIC90% values ranged from 0.05%v=v (lemongrass oil) to 0.46%v=v
(marjoram oil) to Gram-positive bacteria and from 0.10%v=v (clove oil) to 0.56%v=v (ginger oil) to Gramnegative
strains. However, the MIC90% assessed on minced meat inoculated experimentally with foodborne
pathogen strains and against natural microbiota of meat did not show the same effectiveness, and 1.3 and 1.0
were the highest log CFU=g reduction values obtained against tested microorganisms