Journal of Food Quality and Hazards Control
Volume:1 Issue: 4, Dec 2014

Sarcocystosis is one of the most widespread parasitic diseases in cattle caused by three main species of Sarcocystis genus. The major aim of this study was to determine the prevalence of Sarcocystis spp. in meat produced in Yazd, central Iran with special reference to species identification, using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). During March 2012 to May 2013, samples were randomly collected from esophagus, heart, diaphragm, intercostal muscle and tongue of 120 slaughtered cattle at Yazd, central Iran. After DNA extraction, PCR-RFLP was used for detection and identification of Sarcocystis spp. The statistical analysis was performed by Chi-Square test, using SPSS software (v. 16.0). The molecular analysis showed that Sarcocystis spp. was found in 112 of 120 (93.3%) slaughtered cattle. The prevalence of S. cruzi, S. hirsuta and S. hominis were 90%, 38.3% and 57.5% respectively. Among the 112 infected cattle, single and multiple (infected by more than one species) infection were seen in 45 and 67 cattle, respectively. No significant association was detected between sex, age, sample type and the prevalence of Sarcocystis spp. (p>0.05). Considering its public health importance, high prevalence of S. hominis should be highlighted in this region. To the best of our knowledge, this study is the first of its kind to be conducted in Iran. More detailed studies are needed to describe the distribution pattern and species identification of Sarcocycstis spp. in other regions of Iran.

The dispersed phase volume fraction plays key role in oil-in-water emulsion stability by different mechanisms like partial flocculation, depletion flocculation and bridging flocculation. Since the mentioned mechanism is affected by emulsifier concentration presented in system, the major aim of this study was to investigate the effect of dispersed phase volume fraction on physical stability of oil-in-water emulsion in the presence of gum tragacanth. The effect of oil concentration on the stability of oil-in-water emulsion systems containing 0.5% w/w gum tragacanth is investigated by considering rheological properties and droplet size distribution. Emulsion stability was monitored by measuring the extent of gravitational phase separation. Rheological properties and droplet size distribution were measured by rheometer and static laser diffraction immediately after preparation at 25 ºC. All treatments were performed three times and the data were analyzed using SPSS 16.0. Oil concentration enhancement from 10% to 30% w/w decreased emulsion stability. Increasing the oil concentration enhances consistency coefficient from 2.01 to 5.73 pa.sn but decreases flow behavior index. Considering the particle size distribution revealed that number mean diameter increase significantly by oil concentration addition. Emulsion stability index decreased by increasing dispersed phase volume fraction. Considering rheological properties and droplet size distribution, it seems that oil concentration addition however, makes the system more structured but it is unable to create a stable system since the emulsifier is insufficient to protect oil droplets from aggregation.

Escherichia coli and Staphylococcus aureus as important food-borne pathogens are the main concerns of food producers and consumers which create a lot of problems worldwide. The objective of this study was to investigate the inhibitory effect of monolaurin alone and in combination with EDTA on viability of E. coli and S. aureus in culture media and Iranian white cheese. The minimum inhibitory concentration of monolaurin and EDTA was determined by broth microdilution susceptibility test. In the next stage, 108 CFU/g of E. coli and S. aureus and different concentrations of monolaurin and EDTA were added. Samples were maintained at 4 °C for 9 days. Antibacterial effect of monolaurin and EDTA was evaluated on days 0, 1, 3, 5, 7 and 9 by the specific media. Statistical analysis was made using analysis of variance (ANOVA) by SPSS program (16.0) to compare means with a significant difference when p<0.05. Monolaurin alone in both in vitro and in vivo condition had limited effect on E. coli growth but this effect was increased when it was used in combination with EDTA (p<0.05). Monolaurin showed strong antibacterial effect on S. aureus which was increased significantly when used in combination with EDTA (p<0.05). Preservation time had significant effect on antibacterial effect of monolaurin on both pathogenic bacteria (p<0.05). Monolaurin can be used in combination with EDTA to decrease contamination risks and growth of pathogenic bacteria in Iranian white cheese.

Considering the wide consumption of some synthetic antioxidants and their probable negative health effects, in this study, the protective effects of Satureja hortensis L. extracts in stabilizing soybean oil against oxidation at different concentrations (200 and 400 ppm) were tested. The aerial parts of S. hortensis L. were collected from Isfahan province and extracted with 100 ml methanol and ethanol. Soybean oil was selected due to its unsaturated fatty acids variety. Antioxidant activity of the extract was evaluated using 2, 2-diphenyl-1-picrylhydrazyl test. A β-carotene-linoleic acid assay was also applied for the antioxidant capacity. Total phenolic and flavonoid content, peroxide value and thiobarbituricacid-reactive substances (TBARs) were measured for the soybean oil samples. Experiments were carried out in triplicates and data were processed with ANOVA test by SPSS software (16.0). S. hortensis L. extracts had significantly (p≤0.05) lower peroxide and thiobarbituric acid value of samples during storage at 60 °C. The half maximal inhibitory concentration (IC50) values for methanol and ethanol extracts were 31.5±0.7 and 37±0 µg/ml, respectively. In the β-carotene/linoleic acid system, methanol and ethanol extracts exhibited 87.5%±1.41 and 74%±2.25 inhibitions against linoleic acid oxidation. The total phenolic and flavonoid contents of methanol and ethanol extracts were (101.58±0.26 mg/g) and (96±0.027 mg/g), (44.91±0.14 mg/g) and (14.3±0.12 mg/g) expressed in gallic acid and quercetin equivalents, respectively. Methanol and ethanol extracts of S. hortensis could be prepared and added to the commercial vegetable oils as natural antioxidant and so they may be suitable alternative for some synthetic antioxidants.

In current study, chemical composition and antibacterial activity of leaves and flowers essential oils of Origanum vulgare ssp. gracile against four food-borne pathogens including Escherichia coli, Listeria monocytogenes, Salmonella thyphimurium and Staphylococcus aureus were examined. The different organs (leaves and flowers) of O. vulgare ssp. gracile were harvested at flowering stage from wild grown plants in Kurdistan province, Iran. Phytochemical properties of the essential oils were identified by GC and GC/MS analysis. Also, antibacterial effects of O. vulgare ssp. gracile against each bacterial strain were detected by calculating the minimum inhibitory concentration and minimum bactericidal concentration using micro dilution method. Data was analyzed by chi square and fisher exact tests using SPSS 16.0. Main components of leaf and flower oils were carvacrol (46.5% and 60.6%), γ-terpinene (13.91% and 16.64%) and ρ-cymene (13.54% and 7.21%). E. coli and S. aureus had similar sensitivity to essential oils, but S. typhimurium showed more sensitivity. Output of composition analysis showed that the O. vulgare ssp. gracile flowers essential oil has more effect than those from leaves. This work showed substantial inhibitory effect of O. vulgare ssp. gracile essential oils on food-borne pathogens. The efficiency of O. vulgare ssp. gracile flowers oils in reduction of the bacterial activity was higher than the leaves essential oils. According to the results of this research, this essential oil can be utilized as a natural preservative in food products.