Antimicrobial activity of essential oil extracts of various onions (Allium cepa) and garlic (Allium sativum)

Antimicrobial activity of different concentrations (50, 100, 200, 300 and 500ml/l) of essential oil extracts of three type of onions (green, yellow and red) and garlic against two bacteria, Staphylococcus aureus, Salmomella Enteritidis, and three fungi, Aspergillus niger, Penicillium cyclopium and Fusarium oxysporum, was investigated. The essential oil (EO) extracts of these Allium plants (garlic and onions) exhibited marked antibacterial activity, with garlic showing the highest inhibition and green onion the lowest. Comparatively, 50 and 100ml/l concentrations of onions extracts were less inhibitory than 200, 300 and 500ml/l concentrations. However, with garlic extract, high inhibitory activity was observed for all tested concentrations. S. aureus showed less sensitivity towards EO extracts inhibition, however S. Enteritidis was strongly inhibited by red onion and garlic extracts. The fungus F. oxysporum showed the lowest sensitivity towards EO extracts, whereas A. niger and P. cyclopium were significantly inhibited particularly at low concentrations. Conclusively, where seasoning is desired, essential oil extracts of onions and garlic can be used as natural antimicrobial additives for incorporating in various food products. r 2003 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.