جستجوی مقالات مرتبط با کلیدواژه « شیرخام » در نشریات گروه « پزشکی »

Contamination of milk and its products with heavy metals cause toxic and adverse effects on human health, especially in children. Therefore, the assessment of milk and its other products for the presence of these metals should be highly considered. Therefore, the present study was carried out to assess changes in the levels of mercury, lead, cadmium, and arsenic in raw milk samples during processes of milk powder production.

A total of 50 raw milk, skim milk, and cream samples from a dairy plant in Chaharmahal and Bakhtiari Province, Iran, were assessed. These samples were collected in summers and winters, 2019–2020. Samples were analyzed to investigate their lead, mercury, cadmium, and arsenic using the elemental coupled plasma-optical emission spectroscopy method.

Results showed that the residual quantities of heavy metals in various samples varied; hence, metals such as mercury and lead were more concentrated in the cream phase but cadmium and arsenic metals were more concentrated in skim milk (p < 0.05). Furthermore, residual quantities of all heavy metals in milk powder were much higher than those in cream and skim milk (p < 0.05). Based on the results of this study, international standards (Codex), and Iranian national standards, the average quantities of lead in all products were higher than those of standard levels (20 ppb). Quantities of cadmium in skim milk in the cold season and in condensed milk and milk powder in the two seasons were higher than the standard limits (10 ppb).

Based on the results of the present study, quantities of mercury, cadmium, and especially lead in dry milk are higher than the limit set by the Codex, which can be a potential risk for children consuming milk. Therefore, it is necessary to regularly monitor potential sources of contamination in raw milk and its products.

Milk is considered as one of the most complete foods, consumption of raw milk contained with aflatoxin M1 and antibiotics has raised consumer concerns. The aim of this study was to determine the level of aflatoxin and antibiotic residues in raw milk in Bojnurd, Khorasan province, Iran. In this study, 40 samples of raw milk from their distribution centers in the city of Bojnourd, were taken randomly in summer and fall of 2016. Samples were evaluated for aflatoxin and antibiotic residues by ELISA method and Coupons kit respectively. Descriptive statistics including means and standard deviations were used to summarize the data. Data was analyzed with SPSS 19. According to the results, no residues of antibiotics were found in raw milk and the aflatoxin concentrations were between 5.1 and 65 ng per ml and the levels were lower than the Iran standards in all samples. According to the results, antibiotics residues and aflatoxin M1 levels in raw milk of Bojnoord city are within the acceptable level. However, it is recommended to evaluate these parameters in all seasons.

Despite the beneficial effects of antibiotics in the treatment of infectious diseases, their residuals in food such as meat, milk and its transmission to human body have harmful effects. The purpose of this study was to monitor the residual antibiotics in raw and pasteurized milk of Maragheh and Bonab townships by four-plate test method (FPT).
For this purpose, 7 Dairy industries in Maragheh, 7 Dairy industries in Bonab, 4 traditional dairies in Maragheh, 5 traditional dairies in Bonab, a unit of milk processing plant in Maragheh, and a unit of milk processing plant in Bonab were chosen randomly. 25 milk samples were collected at 4 repeated different times of the remaining four antibiotics and were studied by plate method (FPT).
Findings: 7 (94/24%) samples of raw milk dairy industries of Maragheh, 15 cases (47/53%) samples of raw milk dairies industry of Bonab, 6(5/37%) samples of raw milk dairies of traditional type in Maragheh 4 (20%) samples, and Bonabtraditionaldairymilk1 (25%) samples of pasteurized milk contaminated Maragheh antibiotic residues were detected and Bonab pasteurized milk samples were found as negative. The results showed that the maximum residual antibiotic in the penicillin and macrolid groups (p>0.05) and the least residual antibiotic was confirmed in enrofloxazin group.
Discussion & According to Iranian milk consumption per capita, these rates of contamination affect considerable part of population especially vulnerable groups like children, pregnant women, the elderly, and patients. This research shows the necessity of legislative and food inspecting organizations to control and minimize these contaminations.

Milk is a full meal that can provide an appropriate growing environment for different bacteria. Hence, it can be hazardous to human health in unpasteurized conditions. The present study was conducted in order to assess the prevalence and antimicrobial resistance of Staphylococcus aureus in raw and pasteurized milks of Sari City in the summer of 2014.
This cross-sectional study was conducted in the summer of 2014 in the city of Sari. Totally, 160 samples- each 200 mL of raw milk were collected from collection and distribution centers (80 samples) of raw milk, and pasteurized milk from food stores (80 samples). Under aseptic conditions, confirmatory tests were carried out in Chapman and Blood agar media. Antibiogram test was performed for positive samples. Results were analyzed using SPSS (Ver. 19) software through the t-test descriptive statistical analysis.
The results showed that 38.75% of 80 samples of raw milk collected were contaminated by Staphylococcus aureus, while no contamination was observed in pasteurized milk samples. The average number of colony formation of raw milk was estimated to be within 3×104 to 7×104 Cfu/mL. Maximum sensitivity was found against vancomycin, gentamicin, and Co-trimoxazole antibiotics and the maximum resistance was observed against ampicillin, methicillin and cephalotin antibiotics with of 87.5, 25, and 12.5%, respectively.
The raw milk showed the prevalence of Staphylococcus aureus. Therefore, compliance with and control of sanitation at different steps of preparation, supplying and consumption of milk can prevent the human infection with this type of contamination.

Listeria monocytogenes is a psychrophilic bacterium with drought-resistant characteristics and also stable in osmotic stress; these abilities of Listeria make it grow in food stuff, leading to contamination. The aim of this study was to assess the frequency of Listeria species in raw milk and traditional unpasteurized dairy products in Isfahan, Iran. A total of 292 samples of raw milk and traditional, unpasteurized dairy products was examined for presence of Listeria spp. using a two-step selective enrichment recommended by USDA. All isolates were subjected to standard biochemical test. L. monocytogenes strains were further confirmed by PCR amplification. Of 292 samples, 21 (7.19%) and 4 (1.36%) were positive for Listeria spp. and pathogenic L. monocytogenes, respectively. The prevalence of Listeria spp. in raw milk, ice cream, cream, and freni was 5/91 (5.49%), 12/63 (19.04%), 3/27 (11.11%) and 1/25 (4%), respectively. Listeria was not detected from yogurt, butter, kashk, and cheese. Listeria innocua at 16/21 (5.44%) was the most prevalent species isolated, followed by L. monocytogenes at 4/21 (19%) and L. seeligeri at 1/21 (4.7%). All strains of L. monocytogenes identified by biochemical tests were also confirmed by PCR. The study shows the prevalence of L. monocytogenes in raw milk and traditional dairy products sold in the market. Consumption of raw milk with mild heat treatment or its usage in traditional dishes is a common practice in Iran. Therefore, the lack of appropriate control measures could pose serious health problems. The lack of knowledge of the risks of Listeriosis transmission indicates the need for implementation of a food safety education program. In addition, the Iranian food safety authorities should urgently set up an effective standard to screen all susceptible food products for presence of Listeria.

Aflatoxins are secondary metabolites produced by certain strains of the fungi Aspergillus such as Aspergillums flavus, Aspergillus parasiticus and rarely Aspergillus nominus. These fungi are everywhere and can occur in an extensive variety of agricultural products, such as cereals, nuts, spices, dried fruit. Aflatoxins are very toxic, mutagenic, immunosuppressive, teratogenic and carcinogenic compounds. The key target organ for toxicity and carcinogenicity’s the liver. Aflatoxin M1 (AFM1) is the monohydroxylated derivate of AFB1, metabolized by cytochrome P450 enzyme system in liver. European community and Codex alimentary determined 50 ng/l the maximum level of AFM in raw milk, liquid.The purpose of this study was to systematically review studies was done in Iran and survey this results in terms of safety in the presence and amount of aflatoxin M1in milk and dairy products.The databases were searched from 2005 to 2013 and 52 relative articles were obtained and 22 papers which them were elected and reviewed. Articles and specific databases such as SID, PubMed, Elsevier, Science Direct, WHO were searched for related subjects cited since 2005.The contamination of milk and other dairy product in most studies are exceeding from the standard set by the Codex Alimentarius Commission and the ISIRI. According to results obtained in this study the focus was in the pasteurized and sterilized milk and in the more of them the contamination of aflatoxin was above of the European community and Codex Alimentary and the incidence and contamination levels of AFM1 in more cities of Iran seem to be a serious problem for public health, especially infants and children.

Milk and milk products are very suitable medium for growing microorganisms (e. g. Bacillus cereus). B. cereus is spore former bacilli، which easily survives during pasteurization and makes several problems in dairy industries. The aim of this study was to investigate aerobic spore and B. cereus of receiving raw milk from three UF plants.

Samples were gathered from raw milk transport tankers arrived to plants during 30 days in winter. Also، the swab test was used for detection of B. cereus residual on milk contact surfaces.

High contamination level of aerobic spores (AeSC) and especially B. cereus were found in most samples compared with the criteria established by national and international standards. Although total viable count (TVC) in samples from industrial farms (IF) was lower than those from traditional farms (TFs) and milk collection centers (MCCs)، considerable AeSC and B. cereus were transmitted to the UF plants from IFs. The highest and lowest TVC and B. cereus were found in samples from IFs and MCCs، respectively. In addition، our investigation in IFs revealed that teats contamination to soil and feces، as well as contaminated bedding might were the most important sources of B. cereus and AeSC of raw milk. Moreover، the results of swab tests confirmed that the “cleaning in place” system may not remove B. cereus effectively.

It seems that for classifying raw milk quality، AeSC might be used as a more effective quality factor than TVC. Management commitment is effective to improve quality by balance between the amount and quality of receiving raw milk. This leads to the lower contamination in dairy plants and final products.