Antibacterial activity of essential oils and their active components from Thai spices against foodborne pathogens

Abstract

As the popularity of organic food especially fresh vegetables is increasing, it is a common practice to replace chemical fertilizers by manure which leads to high bacterial contamination. Some essential oils such as Thymus vulgaris (thyme) and Ocimum basilicum (basil) oils reduce spoilage flora and foodborne pathogens when used in washing water. This information prompted us to search for effective essential oils from Thai spices for vegetable washing products. Seven out of nine essential oils; fingerroot (Boesenbergia pandurata (Roxb.) Schltr.), galanga (Alpinia galanga (L.) Willd.), holy basil (Ocimum tenuiflorum L.), makrut leaf, makrut peel (Citrus hystrix DC.), sweet basil (O. basilicum L.), and turmeric (Curcuma longa L.) oils showed antibacterial activity. The active components were identified by thin layer chromatography (TLC) bioautography, preparative TLC, and gas chromatography-mass spectrometry. The results indicated that the active components were major components of the oils. The essential oils exhibited higher potency than their active components suggesting that the whole essential oils were more suitable than the pure compounds for product development.