جستجوی مقالات مرتبط با کلیدواژه « fractional inhibitory concentration » در نشریات گروه « صنایع غذایی »

Malva sylvestris belongs to Malvaceae familyThe biological active compounds of Malva sylvestris describe probably it’s biological activities and therapeutic activity. The purpose of this study was to investigate the antibacterial effect of Malva sylvestris on some pathogenic bacteria “in vitro”.In this study, the extraction was carried out by the maceration method. The pour plate method and disk diffusion method were adopted to determine the susceptibility of the pathogenic strains against Malva sylvestris extracts. The broth microdilution and fractional inhibitory concentration index (FICI) were employed to determine antimicrobial effect. The minimum bactericidal concentration was measured by pour plate method. The concentration 100 mg/ml of the ethanolic extract showed the best result on Streptococcus pyogenes and Staphylococcus aureus (p<0.05).  Enterobacter aeruginosa was resistant to most of the aqueous and ethanolic Malva sylvestris extracts. Minimum inhibitory concentration of the ethanolic extract of Malva sylvestris for Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli and Enterobacter aeruginosa were 8, 8, 64 and 64 mg/ml, respectively and the aqueous extract were 16, 32, 128, and 128 mg/ml, respectively.The ethanolic extract of Malva sylvestris had more inhibitory effect than the aqueous extracts on pathogenic strains. Furthermore, aqueous and ethanolic Malva sylvestris extracts showed greater inhibitory effect on gram-positive bacteria in comparison with gram-negative bacteria.

Clove and Fennel have been widely used in traditional medicine for treatment of diseases. Regarding the existence of the active biological compounds in these plants, it seems that these plants have considerable antibacterial effects.In this experimental study, the Kirby–Bauer, the dilution method in the liquid medium and minimum bactericidal concentration (MBC) were used to evaluate and compare the antibacterial effects of the Clove and Fennel essential oils. The interactions were determined by calculating fractional inhibitory concentration (FIC), according to the European Committee for antimicrobial susceptibility testing protocol. The checkerboard method was performed using 96-well microtiter plates. The results showed that Staphylococcus epidermidis was the most sensitive strain to Clove and Fennel essential oils. The effects of interaction of Clove and Fennel essential oils with chloramphenicol antibiotic on all bacteria showed synergistic status (except for the fennel essential oil on Bacillus cereus). Calculation of fractional inhibitory concentration indicated that there was no interaction between the Clove and Fennel essential oils on Salmonella typhi, Enterobacter aerogenes and Staphylococcus epidermidis. Regarding the checkerboard data, one FICIs (>0.5 to 1) indicated the additive effect (Bacillus cereus). Bacillus cereus is one of the most important bacteria that causing food poisoning, it is possible to use a combination of Fennel and Clove essential oils as a natural preservative in the food industry.

Hyssopus officinalis and frankincense (Boswellia carteri), as valuable medicinal herbs, are widely used in traditional medicine. Due to the increased resistance of pathogenic microorganisms to antibiotics and increasing of treatment costs, attentions has been focused to compounds of natural origin. In this study, Hyssop and Frankincense oils were extracted separately by water distillation. The essential oils components were identified by GC/MS. Determination of inhibition zone diameter and minimum inhibitory concentration were performed by disk agar diffusion and macro dilution methods, respectively. Wells with no discoloration were used to detect the minimum bactericidal (fungicidal) concentration. In this research, 24 and 22 compounds were identified in Hyssop and Frankincense, respectively. The main component of Hyssop oil was cis-3-pinanone (%28.2), and the main component of Frankincense oil was α- pinene (%22). Both Hyssop and Frankincense oils had the highest effect on Staphylococcus aureus and Bacillus cereus, and the lowest growth zone diameter was related on Escherichia coli and Pseudomonas aeruginosa. Also, it was found that the Candida albicans was more sensitive than Aspergillus niger against both essential oils (p<0.05). The results showed that plants are rich in secondary products such as terpenoids, alkaloids and flavonoids, most of which have antimicrobial activity.

The complex composition of the essential oils and the variety of chemical structures of their constituents are responsible of a wide range of biological activities many of which are of increasing interest in the field of foodstuff preservation (Romanazzi et al. 2012). Regarding that higher amount of EOs are required for food preservation, their application can negatively influence taste or odor. To avoid this unwanted side effect, several EOs can be combined. On the other hand the synergistic possible effect produced by the combination of plant essential oils was referred as an efficient strategy to combat microbial development(Wagner. 2011). The main purpose of this study was to evaluate the antifugal synergistic effect of combination of some essential oils including thyme, cinnamon, rosemary and marjoram aginst apple rot fungi during posthrvest storage. In this experiment, chemical composition of the essential oils was analyzed by gas chromatography. For evaluation of antifungal activity based on MIC, against Alternaria alternanta, Penicillium expansum and Botrytis cinerea, an agar dilution method was used. EOs interactions were assessed using a checkerboard microdilution method. The evaluated concentrations were in the range of 5 dilutions below the MIC to twice the MIC. For the double combinations, a two-dimensional checkerboard with twofold dilutions of each EOs was used (six double combinations). The maximum antifungal activity was demonstrated by thyme oil which showed MIC values 1250 μg/mL for A. alternanta and P.expansum and 625 μg/mL for B. cinerea .Cinnamon oil with MIC values1250 μg/mL against A. alternanta and B. cinerea and 2500 μg/mL against P.expansum displayed more inhibitory effects than rosemary and marjoram essential oils. In antifungal synergy testing, some double combinations (thyme/rosemary, thyme/cinnamon and cinnamon/marjoram) were found to be synergistic (FICi≤0. 5). The in vivo assay also demonstrated considerable inhibitory effects of EO combination treatments. Results from artificial wounding of trated apple indicated that double combination of thyme/cinnamon (156, 312 μg/mL) has more inhibitory effect than single EO treatments. Although the major components of thyme and cinnamon (especially thymol, carvacrol and cinnamaldehyde) are very important for their antifungal activity, other less-active compounds in rosemary and marjoram (such as α–Pinene, 1.8-cineole, Terpinene-4-ol and γ-Terpinene) play a significant role, as they can strengthen the effects of major components, though synergistic effects have also been observed

Essential oils are aromatic compounds that come from different parts of the plant and is widely used in the food industry. In the present study, it is evaluated the antioxidant activity, phenolic compounds, antimicrobial effect and interaction of the essential oils of Curcuma longa and Ocimum basilicum on some pathogenic bacteria.The essential oil was extracted through the hydrodistillation method. The antibacterial effects Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the essential oils were assessed on pathogenic bacteria, listeria innocua, Staphylococcus epidermidis, Salmonella typhi and Enterobacter aerogenes by microdilution technique using chloride Triphenyltetrazolium. Interaction of basil and turmeric essential oils were also studied by fractional inhibitory concentration (FIC).Total phenolic content (TPC) and antioxidant capacity of essential oils were evaluated using the Folin–Ciocalteu method and DPPH assay. The DPPH of the basil and turmeric essential oil were equal to 31.2 and 18, respectively. The results showed that the ranges of minimum inhibitory concentration of the oils were 4.6-73.6 and 2.3-36.8 mg/ml, respectively, for Curcuma longa and Ocimum basilicum . the ranges of minimum bactericidal concentration of the oils were 9.2-147.2 and 4.6-73.6 mg/ml, respectively. Basil essential oil is effective to control the growth of bacteria. Moreover, the combination of basil and turmeric essential oils confirmed additive activities against the listeria innocua and Enterobacter aerogenes.