Characterization and antimicrobial activity of essential oils of industrial hemp varieties (Cannabis sativa L.)

The present study focused on inhibitory activity of freshly extracted essential oils from three legal (THC<0.2% w/v) hemp varieties (Carmagnola, Fibranova and Futura) on microbial growth. The effect of different sowing times on oil composition and biological activity was also evaluated. Essential oils were distilled and then characterized through the gas chromatography and gas chromatography-mass spectrometry. Thereafter, the oils were compared to standard reagents on a broad range inhibition of microbial growth via minimum inhibitory concentration (MIC) assay. Microbial strains were divided into three groups: i) Gram (+) bacteria, which regard to food-borne pathogens or gastrointestinal bacteria, ii) Gram (-) bacteria and iii) yeasts, both being involved in plant interactions. The results showed that essential oils of industrial hemp can significantly inhibit the microbial growth, to an extent depending on variety and sowing time. It can be concluded that essential oils of industrial hemp, especially those of Futura, may have interesting applications to control spoilage and food-borne pathogens and phytopathogens microorganisms. (C) 2009 Elsevier B.V. All rights reserved.