42 research outputs found
Inhibitory Effects of Several Essential Oils towards Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B
Plant essential oils are natural products extracted from plants and because of their antimicrobial properties can be used as natural additives in foods. They are also useful for decontamination of food-borne pathogens and can be a safe additive in foods. The antimicrobial activities of essential oils belonging to Saturiea hortensis, Thymus vulgaris, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint) were investigated at different concentrations (0.1, 0.3, 0.5, 1, 2, 5 and 10%v/v) against Salmonella typhimurium, Salmonella paratyphi A and Salmonella paratyphi B by using the agar well diffusion method. Essential oils showed inhibitory effect on Salmonella spp. in the agar well diffusion assay. In addition, the capability of essential oils for decontamination of minced row beef, ground beef, minced raw chicken and minced raw fish inoculated with Salmonella spp. at 0.1 and 0.5%v/v were assessed. Reduction of the Salmonella spp. population was observed following the inoculation of the cultures with 0.1 and 0.5%v/v essential oils
Decontamination of tomato, red cabbage, carrot, fresh parsley and fresh green onion inoculated with Shigella sonnei and Shigella flexneri by some Essential oils (in vitro condition)
Background: Essential oils and their major constituents are useful sources of antimicrobial compounds. There are a few reports on the decontamination and antimicrobial activity of essential oils towards Shigella spp.Materials and Methods: In this study, the antimicrobial and decontamination potentials of essential oils at different concentrations, belonging to plants such as Thymus vulgaris, Saturiea hortensis, Mentha polegium, Cuminum cyminum, Lavandula officinalis and Mentha viridis L. (spearmint), towards Shigella sonnei and Shigella flexneri were investigated. The disk diffusion method demonstrated the antimicrobial potential of the essential oils.Results: The ability of essential oils to decontaminate vegetables such as, tomato, red cabbage, carrot, fresh parsley and fresh green onion that were previously inoculated with Shigella spp. was determined. Inhibitory effects of essential oils towards Shigella spp. were noted in the disk diffusion method. There was a reduction in Shigella population following inoculation of cultures with 0.5% and 0.1% (v/v) essential oils.Conclusion: This study confirmed that essential oils have the potential to be used for decontamination of vegetables
Analysis of chlorpheniramine in human urine samples using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography
A simple and environmentally friendly microextraction technique was used for determination of chlorpheniramine (CPM), an antihistamine drug, in human urine samples using dispersive liquid-liquid microextraction (DLLME) followed by high performance liquid chromatography with diode array detection (HPLC-DAD). In this extraction technique, an appropriate mixture of acetonitrile (disperser solvent) and carbon tetrachloride (extraction solvent) was rapidly injected into the urine sample containing the target analyte. Tiny droplets of extractant were formed and dispersed into the sample solution and then sedimented at the bottom of the conical test tube by centrifugation. Under optimal conditions, the calibration curve was linear in the range of 0.055-5.5 µg mL-1, with a detection limit of 16.5 ng mL-1. This proposed method was successfully applied to the analysis of real urine samples. Low consumption of toxic organic solvents, simplicity of operation, low cost and acceptable figures of merit are the main advantages of the proposed technique
Effect of different strains of Saccharomyces cerevisiae on reduction of aflatoxin B1, B2, G1 and G2
Saccharomyces cerevisiae is one of the major microorganisms widely used in food fermentation, and the ability of its strains to reduce the level of aflatoxins has been reported. The aim of this study was to test the capability of S. cerevisiae strains on reduction of aflatoxin B1, B2, G1 and G2 levels. For this reason, standard strains of PTCC 5052 and PTCC 5269 were cultivated on Yeast Mold Agar. Afterwards, cell suspension containing 107 cell/ml was spiked into PBS (pH= 7.2) containing 20 ng/ml of each B1, B2, G2 and G1 aflatoxins. Aflatoxin levels were determined using HPLC and immunoaffinity columns. The results show that different strains of S. cerevisiae reduced the aflatoxin levels in a different rate and various durations. At the time 320 min the PTCC 5052 strain reduced the aflatoxin B1, B2, G1 and G2 levels to 11.2 , 13.9, 8.0 and 8.1%, respectively; meanwhile, these results for the PTCC 5269Â strain 9.5, 8.0, 2.3 and 16.2%, respectively. Results suggested that different strains of S. cerevisiae had a different reduction rate on aflatoxins. Moreover, the strains need to have sufficient time to absorb the maximum amounts of aflatoxin