title: Chemical composition and antimicrobial effects of essential oils of Eucalyptus globulus, Myrtus communis and Satureja hortensis against Escherichia coli O157:H7 and Staphylococcus aureus in minced beef.
abstract: Essential oils (EOs) extracted by hydrodistillation from leaf parts of Algerian Eucalyptus globulus, Myrtus communis and Satureja hortensis were analyzed by gas chromatography/mass spectrometry (GC/MS). The main components of EOs obtained were γ-terpinene (94.48%), 1,8-cineole (46.98%) and carvacrol (46.10%), respectively, for E. globulus, M. communis and S. hortensis. The in vitro antimicrobial activity of the EOs was evaluated against Staphylococcus aureus CECT 4459 and Escherichia coli O157:H7 CECT 4267 using the agar diffusion technique. Results revealed that E. globulus and S. hortensis EOs had more antibacterial effects than that from M. communis. Minimal inhibitory concentrations (MIC) showed a range of 0.05-0.22% (volume by volume [v/v]). Sensitivity of gram-positive S. aureus was much higher than that of gram-negative E. coli. Plant EOs were added to minced beef (two-fold MIC value) at 0.10-0.44%, experimentally inoculated with the same pathogens at a level of 5 × 10(5) colony forming units (cfu)/g and stored at 5 ± 2 °C. Results showed that the EOs of E. globulus and S. hortensis had remarkable antibacterial properties, higher than that of M. communis, against S. aureus and E. coli. Indeed, a reduction of 5.8 log cfu/g (70.74% of reduction) was recorded after 7 days of storage for S. hortensis against E. coli. However, regarding S. aureus, both S. hortensis and E. globulus caused a highly significant (p < 0.05) decrease of microbial counts, most evident after 5 days of storage; S. aureus numbers were 3.50 and 2.50 cfu/g, respectively, corresponding to a reduction of 2.20 and 3.20 log cfu/g (38.60 and 56.14% of reduction) after 1 week of storage. Sensory evaluation revealed that the aroma of minced beef meat treated with EOs was acceptable by panelists at the levels used.
authors: Département de Biochimie et de Microbiologie, Université Mouloud Mammeri. BP 17-15000-Tizi-Ouzou, Algeria.
authors: D
authors: D
authors: Djenane
authors: J
authors: J
authors: Yangüela
authors: T
authors: T
authors: Amrouche
authors: S
authors: S
authors: Boubrit
authors: N
authors: N
authors: Boussad
authors: P
authors: P
authors: Roncalés
mesh_terms: D000462:Algeria; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D002417:Cattle; D000081005:Cyclohexane Monoterpenes; D003511:Cyclohexanols / Q000032:analysis / Q000494:pharmacology; D000081007:Cymenes; D019453:Escherichia coli O157 / Q000187:drug effects*; D000077591:Eucalyptol; D005052:Eucalyptus / Q000737:chemistry*; D005511:Food Handling; D005520:Food Preservatives / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008460:Meat / Q000032:analysis / Q000382:microbiology*; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests; D039821:Monoterpenes / Q000032:analysis / Q000494:pharmacology; D031651:Myrtus / Q000737:chemistry*; D009812:Odorants; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D031362:Satureja / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D000081005:Cyclohexane Monoterpenes; D003511:Cyclohexanols; D000081007:Cymenes; D005520:Food Preservatives; D039821:Monoterpenes; D009822:Oils, Volatile; C018669:gamma-terpinene; C073316:carvacrol; D000077591:Eucalyptol