Background: Plants are rich source of therapeutic phytochemicals used for treating various
ailments. In specific, spices are used in Indian and Chinese system of medicine. Although spices are
traditionally used as food preservatives besides food color and flavor, their medicinal values remain unrecognized.
This paper discusses the antibacterial activities of essential oil samples extracted from selected
spices (cardamom, ginger and turmeric) belonging to Zingiberaceae, the ginger family.
Methods: The essential oils from rhizomes of ginger (Zingiber officinale R.) and turmeric (Curcuma
longa L.) as well as capsules of cardamom (Elettaria cardamom M.) were extracted by hydrodistillation.
The oil samples were analyzed by gas chromatography/mass spectrometry (GC/MS). The
chemical composition was identified based on the retention index, and also by co-injection with authentic
standards. The oil samples were also evaluated for their antibacterial activities.
Results: The major composition of cardamom is 1,8-cineole (40.11%) and α-terpinyl acetate (39.24%).
In the case of ginger, it is dominated by zingiberene (32.01%) followed by β–sesquiphellandrene
(16.25%) and farnesene (12.52%). In turmeric, the major composition is found to be turmerone
(32.55%) followed by ar-turmerone (23.15%) and curlone (23%). Besides other compounds such as
1,8-cineole, α-curcumene, α-terpinene, α-thujene, β-myrcene, β-sesquiphellandrene, γ-terpinene, limonene,
linalool, terpinolene, (Z)-citral and zingiberene were present in varying levels.
Conclusion: The spice oil samples were more effective against Gram positive than Gram negative
bacteria. The constituents of cardamom oil are highly antibacterial than ginger and turmeric oils. It
was found to inhibit Lactobacillus sp., a probiotic Gram positive bacterium. The probiotic inhibitory
potential of essential oils is in the following order: ginger > cardamom > turmeric. Although essential
oils are generally recognized as safe, it may potentially inhibit probiotic bacteria. Hence, more
research is required in this direction.