Antimicrobial effect of essential oils: a systematic review

Regarding the harmful effects of chemical foods preservatives on human body, it is crucial to find out safe antimicrobials among essential oils and herbs. This study aimed to address the effects of different essential oils on various bacterial species through a systematic review. A wide range of published papers in national and international data bases have been searched for the relevant articles. For this reason, the keywords used in searching were: "essential oils in food", "antimicrobial effect" and "vegetable oils". Among 462 retrieved articles, 76 papers were selected for further reviewing based on their title and abstracts. Based on results, the antimicrobial effects of different essential oils on pathogenic and spoilage organisms were compared. Moreover, the most effective as well as the least effective essential oils on microbial growth were identified. It was concluded that essential oils are more effective on gram positive bacteria rather than gram negatives. Besides, it was evident that some essential oils negatively affected the useful organisms such as lactobacilli.