Essential oil from five Zingiberaceae for anti food-borne bacteria

Essential oil from five Zingiberaceae species: ginger (Zingiber officinale Roscoe.), galanga (Alpinia galanga Sw.), turmeric (Curcuma longa L.), kaempferia (Boesenbergia pandurata Holtt.) and bastard cardamom (Amomum xanthioides Wall.) obtained by hydrodistillation and two solvent extractions (petroleum ether and ethanol) was characterized. Their antibacterial effects towards Escherichia coli, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were tested by a disc diffusion assay. Essential oil of kaempferia and bastard cardamom obtained by hydrodistillation extraction could inhibit growth of all tested bacteria. Essential oil of ginger extracted by hydrodistillation had the highest efficiency against three positive strains of bacteria (S. aureus, B. cereus and L. monocytogenes), with a minimum concentration to inhibit B. cereus and L. monocytogenes of 6.25 μg/ml. Volatile compounds of all extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). The major components of ginger, galanga, turmeric, kaempferia, and bastard cardamom obtained by hydrodistillation, were zingiberene, methyl chavicol, turmerone, γ-terpinene, and methyl chavicol, respectively.