Abstract:The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of garlic essential oil against two phenylethylamine-and tyramine-producing bacteria-Enterococcus faecalis and Enterococcus faecium-were measured in vitro using the double tube dilution method. The effects of a variety of concentrations of garlic essential oil on the two strains with high phenylethylamine-and tyramine-production were measured by high performance liquid chromatography (HPLC), to determine the inhibitory effect of garlic essential oil on biogenic amine production by the two strains. The results showed that garlic essential oil displayed sstrong antimicrobial activity against E. faecalis and E. faecium, and the corresponding maximum inhibitory rates (IRs) reached 52.41% and 48.20%, respectively. The antimicrobial effect increased as the concentration increased. When the amount of added garlic essential oil was ? MIC, it showed an inhibitory effect on the growth of E. faecalis and E. faecium. At a concentration of 0.025%, the garlic essential oil could significantly reduce the production of phenethylamine and tyramine by the test strains; the production of phenylethylamine and tyramine was reduced by 26.61% and 15.54%, respectively, from of the control. The result indicated that garlic essential oil exhibited a significant inhibitory effect on E. faecalis and E. faecium, thereby reducing the production of phenethylamine and tyramine.
