Biological effects of essential oils and extracts
E. Kianifar; S. Ketabchi
Abstract
Nowadays, considering the side effects of chemical preservatives and the attention of food manufacturers to the natural preservatives, it seems necessary to evaluate the antimicrobial effects of natural preservatives in the laboratory and food models. In this study, the stems and leaves essential oil ...
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Nowadays, considering the side effects of chemical preservatives and the attention of food manufacturers to the natural preservatives, it seems necessary to evaluate the antimicrobial effects of natural preservatives in the laboratory and food models. In this study, the stems and leaves essential oil of Anethum graveolens L. was extracted by Clevenger apparatus and its compounds were identified using GC-MS. The fresh celery juice was stored for 7 days at the room temperature until it was rotten, then the serial dilution was prepared and the bacterial culture was performed using pour plate method. The different bacterial isolates were purified and the antibacterial effect of different essential oil concentrations was investigated by disk diffusion method on the dominant bacteria. The sensitive bacteria to the dill essential oil were identified by the standard microbiological methods and 16S rRNA gene amplification method. Then the effective concentration was added to the celery juice and the effect of essential oil on the population of total and dominant bacteria was investigated. The sensory acceptance of different essential oil concentrations among the population groups was assessed by a five-point hedonic questionnaire. This research was conducted in a completely randomized design with three replications. Based on the GC-MS results, dillapiole (21.2%), α-phellandrene (37.2%), and β-phellandrene (9.2%) were the most important constituents of dill essential oil. The results of sequence blasting showed that Bacillus cereus and Acetobacter fabarum were the most dominant putrefactive bacteria in the celery juice. Based on the results, there was a significant difference between the five concentration groups in terms of halo diameter in the bacteria. The highest halo diameter in both bacteria was obtained at the concentration of 1000. In general, the results of the present study showed that dill essential oil is a suitable additive for the celery juice based on the results of sensory evaluation and in terms of controlling the putrefactive bacteria.
M. Dadashpour; I. Rasooli; F. Sefidkon; M. Taghizadeh; S. Darvish Alipour Astaneh
Abstract
Essential oils with good antioxidant properties could be used for therapeutic, nutritional and food preservation purposes. With the increasing use of medicinal plant products, different aspects need to be considered in terms of useful applications and their potential harm to human health. In the present ...
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Essential oils with good antioxidant properties could be used for therapeutic, nutritional and food preservation purposes. With the increasing use of medicinal plant products, different aspects need to be considered in terms of useful applications and their potential harm to human health. In the present study, antimicrobial, antioxidative and cytotoxic properties of fresh and commercial essential oils of Anethum graveolens L. were studied. The bacterial strains sensitive to Anethum graveolens oils were in the following order: Candida albicans> S. aureus> E. coli> P. aeruginosa. The minimum inhibitory and bactericidal concentrations of the oils were determined. The essential oils had good bactericidal and bacteriostatic properties except for Pseudomonas aeruginosa. Antioxidative properties of the oils were studied using DPPH free radical scavenging and beta-carotene bleaching tests and the results were compared with standard synthetic antioxidants. Lipid peroxidation inhibitions were comparable to the synthetic antioxidants of BHT and BHA. The oil concentration required for 50% free radical scavenging (IC50) was 6.7 μg/ml with total phenol contents of 174.91 μg GAE/mg for fresh oil of A. graveolens, while they were 10.53 μg/ml and 4.34 GAE/mg respectively for the commercial oil. The volatile oils from fresh and commercial A. graveolens displayed cytotoxic effects on human peripheral blood cells (lymphocytes) with IC50 of 7 and 3042μg/ml and on human tumor cell line (HeLa cells) with IC50 of 8.51 μg/ml and 205.65 μg/ml respectively. The results show that essential oils of A. graveolens could be used with caution and after determining the dose.