Chemical composition, antioxidant effects and antimicrobial activities of some spices essential oils on food pathogenic bacteria

• Published in: African journal of biotechnology Vol. 15; no. 16; pp. 649 - 656
• Main Authors: Florentine, M C Ndoye Foe, Maximilienne, A Nyegue, Sylvain, L S Kamdem, Riwom, H S Essama, Fran ccedil ois Xavier, Etoa
• Format: Journal Article
• Language: English
• Published: 20.04.2016
• Subjects: Cinnamomum zeylanicum; Citrobacter freundii; Enterobacter cloacae; Escherichia coli; Morganella morganii; Ocimum gratissimum; Proteus vulgaris; Salmonella typhimurium; Shigella; Staphylococcus aureus; Thymus vulgaris
• ISSN: 1684-5315; 1684-5315
• DOI: 10.5897/AJB2015.15070

Thymus vulgaris, Cinnamomum zeylanicum and Ocimum gratissimum are spices widely used as aroma enhancers and food preservatives. This work assessed the chemical composition, antioxidant and antimicrobial effect of their essential oils on some food pathogenic bacteria, namely, Staphylococcus aureus, Citrobacter freundii, Enterobacter cloacae, Morganella morganii, Escherichia coli, Salmonella typhimurium, Proteus vulgaris and Shigella flexineri. After chemical analyses of the essential oils by gas chromatography and gas chromatography coupled to mass spectroscopy, the antimicrobial effects were subsequently assessed by disk and microdilution methods, while the antioxidant evaluations were performed by free radical scavenging activity. T. vulgaris essential oil composed of p-cymene (45.90%) and thymol (23.72%) which exhibited the highest inhibitory diameters of 20.33 plus or minus 0.58 and 18.00 plus or minus 1 mm, respectively, on the growth of S. aureus and C. freundii. O. gratissimum essential oil with thymol as major compound (47.11%) was more active to inhibit the growth of C. freundii and S. flexineri with respective inhibitory diameters of 18 plus or minus 1.73 and 16 plus or minus 2 mm. Essential oil from dry leaves of C. zeylanicum containing cinnamaldehyde (82.23%) and linalool (12.12%) was found to have the lowest values for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) ( less than or equal to 3.53 mg/mL) considering the growth of S. flexineri, C. freundii and E. cloacae. Regarding the antioxidant effect, C. zeylanicum and T. vulgaris essential oil showed the most scavenging effect with half-maximal DPPH scavenging concentration (SC sub(50)) of 2.5 10 super(-5) and 6.5 10 super(-5) mg/ml, respectively. Their antioxidant effects were higher than conventionally used antioxidants in food products, butylhydroxyltoluene (BHT) and vitamin C.