ESSENTIAL OIL COMPOSITION AND ANTIOXIDANT CAPACITY OF CARUM COPTICUM AND ITS ANTIBACTERIAL EFFECT ON STAPHYLOCOCCUS AUREUS, ENTEROCOCCUS FAECALIS AND ESCHERICHIA COLI O157:H7

摘要

Antibacterial activity, also antioxidant capacity of Carum copticum was evaluated; in addition, a mechanism for its antibacterial action against both Gram positive and Gram negative bacteria were introduced. Presence of antimicrobial constituents (thymol, p-cymene, c-terpinene) were confirmed by gas chromatography/ mass spectrometry. Micro-well dilution and disk diffusion assays were applied to assess the antibacterial activity of C. copticum against Staphylococcus aureus, Enterococcus faecalis and Escherichia coli O157:H7. The mechanism of the antibacterial activity was also evaluated by scanning electron microscopy. Total phenolic concentration of EO was 831.1663.75 mg of gallic acid equivalents per gram of oil. The minimum inhibitory concentrations of EO against S. aureus, E. faecalis and E. coli O157:H7 were 0.044%, 0.07% and 0.05%, (vol/vol) respectively. Moreover addition of C. copticum EO to minced beef at concentrations of 0.75 and 1% significantly enhanced fresh meat odor and color.