Abstract: In this study,we used steam distillation to extract clove and cinnamon essential oils.Components of the two essential oils were analyzed by GC.The antimicrobial effects of the plant oils were studied to inhibit five important foodborne pathogens:Staphylococcus aureus,Escherichia coli,Bacillus subtilis,Salmonella typhimurium and Shigella dysenteriae,to be compared with sodium benzoate and potassium sorbate,the chemical preservatives commonly used now.The experimental results showed that the content of eugenol in clove is 78.1%,and that of cinnamaldehyde in cinnamon 86.8%.The antimicrobial effects of clove and cinnamon oils and their components are stronger than those of chemical preservatives.Cinnamon oil and cinnamaldehyde showed that the strongest antimicrobial effects with their MIC range from 200 to 1600mg/L,only 1/64～1/16 of the ranging of sodium benzoate and potassium sorbate(with their MIC ranging from 6400 to 25600mg/L).Clove oil and eugenol are most active against the foodborne pathogens(with their MIC ranging from 800 to 1600mg/L).

Key words: essential oils, steam distillation, antimicrobial test, MIC(minimum inhibition concentration), cinnamaldehyde, eugenol