نشریه بهداشت مواد غذایی
پیاپی 1 (بهار 1390)

The antimicrobial effect of of different concentrations of Zataria multiflora Boiss. essential oil at supplementation levels of (0, 0.005, 0.015, 0. 03%), on E. Coli O157:H7 was examined in minced beef meat. All of the above concentrations showed acceptable organoleptic properties in minced beef. Eo at 0.03% possessed a strong antibacterial activity against E.Coli O157:H7 in minced beef. The correlation coefficient of different concentrations of zataria multiflora Boiss. essential oil with logarithm of the numbers of E. Coli O157:H7 was –0.701, –0.599 at 4 and 10°C respectively. It was found that effect of different concentrations of essential oil on growth rate of E. coli O157:H7 was statistically significant (p<0.01). In this study, it was found that treatment of minced beef meat with different concentrations of essential oils showed an inhibitory effect on E. Coli O157:H7 during storage at 4°C, but not at 10°C. According to the results of present study, storage at a proper refrigerated storage (4°C) is suggested.

The biological activity of probiotics is affected by various environmental factors which can influence the performance as well as the growth of probiotics for increasing the health of the consumers. This study aims to investigate the effect of inulin, concentrate 0.5, 1, 1.5 and 2% of the primary culture and temperature of 35, 38, 41 and 44°C on the growth and metabolism of L. acidophilus La5 in UHT milk. In order to achieve this, the milk fermented with L. acidophilus La5 (as the culture ferment) was used for incubating the milk sample; incubation at 35, 38, 41 and 44°C were used in order to find the optimum temperature for the growth of microorganisms. The acidity and the pH of the milk samples were measured during 0, 2, 4 and 8 h and lactobacillus counts were performed at 0.4 and 8 h after the incubation period. In order to measure the effect of inulin, 0.5% (w/v) was added to the milk samples, and the resulted samples together with the control sample, were kept at 41°C. Then the acidity, pH and the total number of L. acidophilus of milk samples were determined during the above mentioned periods. Every of above operations were replicate ten times; then, utilizing statistical tests, the average of acidity, pH and enumeration of L. acidophilus were compared with one another during the above mentioned periods. The findings of the study indicat that, lactobacillus count and the amount of acidity in the incubated milk samples at 41 and 44°C were significantly greater than the other temperatures (P<0.05). The growth rate of the bacterium in samples containing 2% of starter culture during the fourth h of incubation was significantly greater than the other samples (P<0.05). However, this difference in 8 h after the incubation was not significant (P>0.05). Concerning the use of prebiotic inulin, the number of L. acidophilus and the acidity of milk samples containing inulin was significantly greater than the number of the bacterium in control sample (P<0.05). It is concluded from this study that, the best alternative temperature for this purpose is an incubation temperature ranging from 41 to 44°C. Addition of inulin enhance significantly the growth of L. acidophilus La5.

This study is done on 200 sheep and 200 goats before slaughtering in Tabriz industrial abattoir. In the middle month of each season, blood samples were achieved from jugular vein, of 50 sheep and 50 goats. Blood samples were stained with Gimsa staining method. The stained slides were assayed with light microscope ´100. According to the results obtained from 200 sheep samples, we observed 37 cases (18.5%) were infected with different blood parasites. Among these samples, 9 cases (9.5%) were infected with babesia ovis, 6 cases (3%) with both babesia ovis and babesia motasi, 11 cases (5.5%) were infected with theileria ovis and 1 case (0.5%) infected with anaplasma ovis. From 200 goats surveyed, we observed 34 cases (17%) were infected with different blood parasites. Among them 28 cases (14%) were infected with babesia ovis, 6 cases (3%) were infections with both babesia ovis and babesia motasi. According to the results obtained, from point of view of blood parasites, in sheep and goats slaughtered in Tabriz industrial abattoir, we observes that the highest rate of infection belongs to babesia ovis and the lowest rate to anaplasma ovis. From seasonal point of view, summer showed the highest rate of infection and winter showed the lowest rate. The infection rate between male and females or between sheep and goats showed no significant differences (P> 0.05).

Antibiotics belong to a category of drugs called “antimicrobials,” and include medicines like penicillin, tetracycline, and amoxicillin. These drugs are used to kill or inhibit the growth of bacteria without causing significant harm to the host (such as a human or an animal). When humans and animals are injected or introduced with antibiotics, the drugs accumulate in the body. These accumulated drugs are called antibiotic residue. Antibiotic residue is detectible in the blood, muscle tissue and body fluids, like milk which can be harmful for consumer’s health as well as dairy industries. The first study was carried out in 1962 in Iran. The results show an increasing trend of antibiotics residue in milk over four decades in the country. It seems that an effective strategy to involve different dimensions of the matter that is government authorized body, farmers and dairy industries for solving the problem is necessary.

The aim of study was to identify intestinal parasitic helminthes among restaurant workers of Tabriz in 2009. For this reason, stool specimens of 270 restaurant workers were collected and examined for the presence of intestinal parasitic helminthes. Three types of techniques were used: direct examination, saline sedimentation and formol-ether concentration. Most of the samples were contaminated at least with one kind of parasite (Hymenolepis nana, Ascaris lumbricoides, Ancylostoma duodenale and Schistosoma mansoni). Whereas, 3 cases were infected with two parasite (Hymenolepis nana, Ancylostoma duodenale). The prevalence rate was 4.8% for Hymenolepis nana, and 1.1% for Ascaris lumbricoides, meanwhile the prevalence rate was 1.8% for Ancylostoma duodenale. Additionally, the blood parasite Schistosoma mansoni was also detected in 2 cases. The infection with these parasites accompanies by abdominal disorders such as diarrhea, constipation and nausea and vomiting. These results indicated that, sanitary measurements were not satisfactory. Therefore, hygienic measures along with efficient pre-employment screening tests must be performed.

Origin of contamination for traditional ice cream consist of using of using primarily contaminated or unpasteurized ingredients (i.e., milk or cream). Determination of coliform- Enterococcns ratio is among methods used for investigation of fecal coliform's origin. This study aims to enumerate fecal coliform and Enterococci as well as their ratio, in order to find out the origin of contamination in traditional ice cream. Consequently, 21 traditional ice cream samples were collected throughout Tabriz. Samples were prepared and then enumation of fecal coliforms and Enterococci were performed according to the Iranian standards (No. 356, 2946 and 2198 respectively). Mean level of contamination for fecal coliforms was 6.67 and for Enterococci was 307.1. on the other hand, the fecal coliforms-Enterococci ratio was determined as 0.0217. Regarding the normal mean ratio of coliforms and Enterococci in cow's intestine, therefore the origin of contamination for traditional ice creams were distinguished as cow's feces which could enter cow's milk direct and lor indirectly.

Milk is one of the most important sources of human nutrition and because of high nutrient content; it is a very suitable medium for microbial growth and spoilage. Sometimes farmers cheat and add some additives to milk in order to cover the spoilage or other defects in milk. In this study 120 samples of bulk raw milk (10 samples each month) were collected from dairy farms of Pakdasht under sterile condition and send to veterinary faculty of Garmsar University. The following tests were done on each sample: Anti-microbial residues, residues milk acidity neutralizer, evaluation of sugar, formalin, Hydrogen peroxide, Salicylic acid and salt presence. Results were analyzed with Spss software and the results of the first six months of the year were compared statistically with the results of the second six months of the year. The mean of antimicrobial agents, milk acid neutralizer, formalin, hydrogen peroxide and salicylic acid showed no significant difference. But sugar in first semester were more than second semester (p<0.05). Also, salt of all samples were determined in normal value.