Food Hygiene: 5 (12)

Open Access Article

1 - Prevalence of six genes encoding enterotoxins production of Staphylococcus aureus isolated from white-brined-cheese by multiplex PCR
سامان Mahdavi

Isolation, identification and grouping of Staphylococcal enterotoxins in milk is of great importance since these toxins are considered as a major potential source of human illness. In this study, 22 coagulasepositive strains of Staphylococcus aureus isolated from white More

Isolation, identification and grouping of Staphylococcal enterotoxins in milk is of great importance since these toxins are considered as a major potential source of human illness. In this study, 22 coagulasepositive strains of Staphylococcus aureus isolated from white brine cheese produced in rural areas of Maragheh, were assessed for the existence of six genes encoding enterotoxin synthesis using multiplex PCR. For this, extracted DNA was subjected to multiplex PCR for the presence of enterotoxin a, b, g, h, i and j genes. Amongst seg was the most frequent (8 strains) gene; meanwhile seb gene was not detected in any of the isolates. According to the results, 9 strains (40.9%) harbored the genes encoding enterotoxin production. Four strains (18.18%) contained more than one enterotoxin gene. The results of this study indicated that most of Staphylococcus aureus isolates in traditional cheeses have the potency to produce enterotoxin.  Manuscript profile

Open Access Article

2 - Introduction and comparison of measurement methods of antifungal properties of lactic acid bacteria in cheese
حسین Sedaghat M.H Eskandari مرضیه Moosavi-Nasab S.S Shekarforoush M.A Hanifpour

Various laboratory methods have been developed to evaluate the effectiveness of anti-mould effect of lactic acid bacteria. However, most of these investigations have been conducted in culture medium. Due to the occurrence of complex interaction between food components a More

Various laboratory methods have been developed to evaluate the effectiveness of anti-mould effect of lactic acid bacteria. However, most of these investigations have been conducted in culture medium. Due to the occurrence of complex interaction between food components and antimicrobial substances produced by lactic acid bacteria, the result achieved from these studies may be different from those seen in food model. In various studies growth inhibition of molds on the surface of foods are considered as antifungal activity. Consequently, introduction and comparison of efficient methods for evaluation of anti-mould effect of lactic acid bacteria would be helpful. In this study, antifungal activity of lactic acid bacteria inoculated in cheese was estimated using Microdilution method. Pieces of cheese samples were overlaid with molds and the antifungal effect of this bacteria was studied against Aspergillus flavus and Aspergillus parasiticus. All three methods showed the effectiveness of lactic bacteria on mold inhibition. Comparison of the results showed that there was significant positive correlation between antifungal overlay assay and direct growth of mold on cheese, since this two test showed antifungal effect in the same way including interaction between bacteria and mold and also producing antifungal compound. Manuscript profile

Open Access Article

3 - Validation of histamine determination Method in yoghurt using High Performance Liquid Chromatography
مریم Jahedinia گیتی Karim ایرج Sohrabi Haghdust S.M Razavi Rohani محبوبه Eskandari

   Biogenic amines are organic, basic nitrogenous compounds of low molecular weight that are mainly generated by the enzymatic decarboxylation of amino acids by microorganisms. Dairy products are among the foods with the highest amine content. A wide variety o More

   Biogenic amines are organic, basic nitrogenous compounds of low molecular weight that are mainly generated by the enzymatic decarboxylation of amino acids by microorganisms. Dairy products are among the foods with the highest amine content. A wide variety of methods and procedures for determination of histamine and biogenic amines have been established. Amongst, HPLC method is considered as reference method. The aim of this study was to validate Reversed Phase HPLC method determination of histamine in yoghurt. The mobile phase consisted of acetonitrile/water (18:88 v/v) and the flow rate was set at 0.5 ml/min using isocratic HPLC. Detection was carried out at 254 nm using UV-detector. Calibration curve that was constructed using peak area of standards was linear and value of correlation coefficient (r2) was estimated at 0.998. Good recoveries were observed for histamine under investigation at all spiking levels and average of recoveries was 84%. The RSD% value from repeatability test was found to be %4.4. Limit of detection and limit of quantitation were 0.14 and 0.42 µ/ml, respectively. The results of validation tests showed that the method is reliable and rapid for quantification of histamine in yoghurt. Manuscript profile

Open Access Article

4 - Determination of copper and cadmium concentration in greenhouse tomatoes produced in Hamadan province during 2012
مهرداد Cheraghi مژگان Sohrabi کامران Shayesteh

Excessive accumulation of heavy metals in agricultural soils not only leads to environmental pollution, but also results in increased uptake of heavy metals by plants, which in turn affects the quality and safety of the foods. Cadmium and copper are considered as the ma More

Excessive accumulation of heavy metals in agricultural soils not only leads to environmental pollution, but also results in increased uptake of heavy metals by plants, which in turn affects the quality and safety of the foods. Cadmium and copper are considered as the major pollutants of greenhouse soils that stem from agricultural techniques and chemical materials. This is a study aimed to investigate the contamination of greenhouse tomatoes crop with copper and cadmium in Hamadan province. A total of 72 samples were obtained from 18 greenhouses (4 samples from each) located in 6 cities of the province. Following preparation procedure, the concentrations of the elements were measured using atomic emission. According to the results, the concentrations of cadmium and copper in tomato samples were estimated at the range of 0.08–5.25 and 0.01–9.25 mg/kg, respectively. Statistical analysis showed a correlation between cadmium and copper concentrations. Moreover, comparing the results with the approved level of these elements revealed that the concentration of cadmium and copper in some of the greenhouse tomatoes were above the acceptable level. That is to say, the concentration of cadmium in all of the samples was determined as health threatening level. Manuscript profile

Open Access Article

5 - Effect of light-salting and drying pre-treatments on physical characteristics and oil uptake in rainbow trout (Oncorhynchus mykiss) nuggets
بهاره Shabanpour انیسه Jamshidi

Reduction of oil uptake in battered and breaded products is one of the critical aspects to obtain a safe and good quality product. In this study, combined effects of light salting (8, 10 %) and microwaving (180 °C, for 30, 60 and 90 s) pre-treatments on physical par More

Reduction of oil uptake in battered and breaded products is one of the critical aspects to obtain a safe and good quality product. In this study, combined effects of light salting (8, 10 %) and microwaving (180 °C, for 30, 60 and 90 s) pre-treatments on physical parameters and oil uptake in rainbow trout nuggets were investigated. Based on results, highest moisture content was observed in control (p˂0.05) group. Moreover, the treatment with 10% light salting and 30 s pre-drying in 180 °C resulted in lowest oil uptake (p˂0.05). No significant differences was observed on the product yield, adhesion of coating, water holding capacity and sensory properties among the treatments. In comparison with control group, all treatments demonstrated lower levels of color indices as well as lower percentage of oil uptake (p˂0.05). As a result, treating the product with 10% light salting and pre-drying in microwave at 180 °C for 30 s is recommended for the reduction of oil uptake in rainbow trout nuggets.   Manuscript profile

Open Access Article

6 - Isolation of coagulase-positive Staphylococcus aureus from meat and intestine of native ducks of Tabriz area
افشین Javadi سیروس Rafei فرهاد Shahian, حامد Ghazi Hashtroudi

Coagulase-positive Staphylococcus aureus is introduced as the third major source of animal origin food borne disease. This bacterium can proliferate and produce toxin in protein and carbohydrate foods leading to food-poisoning. The aim of this study was isolation, ident More

Coagulase-positive Staphylococcus aureus is introduced as the third major source of animal origin food borne disease. This bacterium can proliferate and produce toxin in protein and carbohydrate foods leading to food-poisoning. The aim of this study was isolation, identification and enumerating of S. aureus in meat as well as intestinal contents of native duck around Tabriz area. For this purpose, a total number of 35 native ducks randomly was purchased in the nearby villages of Tabriz. Fifty g of thigh meat together with 10 g of intestinal content of each carcass were sampled and analyzed according to the ISIRI protocols. The isolates were confirmed by PCR technique. Results showed that 17.14% of meat and fecal samples were found contaminated with S. aureus. Mean values of S. aureus load in meat and feces were estimated at 87 CFU/g and 64 CFU/g, respectively. It was assumed that contamination of duck meat with S. aureus can be occurred through non-hygienic practices during slaughter as well as contamination with intestinal contents and/or skin of the carcass. Manuscript profile

Open Access Article

7 - Comparison of calorimetric and HPLC methods in measuring nitrate content of meat products: An economic evaluation
مسعود moradi کیومرث SHarafi سهراب Delangizan ستار Jamshidpoor

Nitrate is a flavors compound, color stabilizer and growth inhibitor of anaerobic microorganisms in meat products. High concentration of nitrate in food can cause methaemoglobinaemia and is recognized as carcinogenic. Therefore, accurate determination of nitrate is cruc More

Nitrate is a flavors compound, color stabilizer and growth inhibitor of anaerobic microorganisms in meat products. High concentration of nitrate in food can cause methaemoglobinaemia and is recognized as carcinogenic. Therefore, accurate determination of nitrate is crucial to ensure consumers’ health. Regularly, nitrate is estimated by colorimetric and HPLC methods. In measurement of nitrate, the efficiency, accuracy, speed and amount of material are important from economical point of view. In this study, the cost of initial investment, staff, consumable material and equipments used by the two methods were calculated and finally Net Present Value (NPV) was estimated for each of them. The rate of interest was considered from 4 until 30%. According to the results the amount of initial investment, annual cost of staff and consumable materials for colorimetric method were determined as 274000000, 379080000 and 214289130 Rials, respectively. These costs for HPLC method were 342000000, 252720000 and 7633080 Rials, respectively. NPV in minimum and maximum rates of interest (4 and 30%) for colorimetric method were 8368344000 and 2242330000 Rials and for HPLC method were estimated at 4035848000 and 1207544000 Rials. As a consequence, HPLC is more economical and could be recommended for the routine measurement of nitrate in of food safety laboratories. Manuscript profile

Open Access Article

8 - Evaluation of organophosphorus pesticide Diazinon residue in greenhouse crops using spectrophotometry (Case Study: Mushroom)
سهیل Sobhanardakani سیمین دخت Sadri سعید Jameh Bozorgi

Pesticides are among the chief sources of environmental pollutants that have impacts on living creatures and humans health. The purpose of this study was to evaluate the concentration of organophosphorus pesticide Diazinon residues in mushroom using Spectrophotometry. A More

Pesticides are among the chief sources of environmental pollutants that have impacts on living creatures and humans health. The purpose of this study was to evaluate the concentration of organophosphorus pesticide Diazinon residues in mushroom using Spectrophotometry. A total number of 10 mushroom samples was collected from the active greenhouses around Hamedan city as well as commercial brands that present their products in Hamedan retails. The samples were prepared and Diazinon residue in samples was read by Spectrophotometer in 3 replicates. Mean value of Diazinon concentration in different commercial brands was estimated at 0.126, 0.125, 0.166, 0.040, 0.130, 0.081, 0.129, 0.132, 0.128 and 0.129 mg/kg that were above the Europe Union Maximum Residue Limit (MRL). Moreover, the comparison of results achieved from the different samples show significant different between greenhouses of 3, 4 and 6 (p>0/05). It was concluded that training of farmers to use appropriate amounts of pesticides would guaranty the safety and health of consumers of agriculture products. Manuscript profile

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