Contamination Of Dairy Products Research Articles

Application of QuEChERS for analysis of contaminants in dairy products: a review.

The safety of dairy products is intrinsically linked to consumer health, and the exceedance of risk indicators, such as pesticide and veterinary drug residues, constitutes one of the primary issues affecting their quality and safety. To assess the safety of dairy products, it is crucial to develop accurate and reliable analytical methods for their detection. Food safety testing involving important indicators such as pesticide residues, veterinary drug residues, mycotoxins and unapproved additives has become a pivotal requirement in the industry field. The QuEChERS (Quick、Easy、Cheap、Effective、Rugged、Safe) method is widely acknowledged as a food safety analysis method currently. This method can effectively extract a wide range of compound classes from diverse matrices in food safety testing, thereby enhancing the accuracy of detection. Additionally, when combined with chromatographic-mass spectrometry techniques, it can simultaneously analyze hundreds of target analytes, rendering it widely applicable in the quality and safety testing of dairy products. Although QuEChERS has rapidly developed in the field of dairy product quality and safety analysis due to its efficiency and speed advantages, certain shortcomings remain, presenting considerable room for improvement. This paper presents a comprehensive review of the utilization and research advancements of the QuEChERS technique in dairy products, with the aim of providing more precise, expeditious, and reliable methods for the safety assessment of dairy products.

Antifungal Activity of Alcoholic Extract of Allium Jesdianum on Fungi-Contaminated Dairy Products.

One of the main sources of contaminated dairy products is moldy fungi, specifically species of Aspergillus and Penicillium. This study aimed to evaluate the effect of the alcoholic extract of Allium jesdianum plant on the growth of molds contaminating dairy products in Isfahan. In this research, 200 samples of dairy products were gathered from different areas of Isfahan city, including 70 samples of cheese, 60 samples of buttermilk, 40 samples of yogurt, 20 samples of curd, and 10 samples of cream. The antifungal activity of Allium jesdianum plant was investigated by the diffusion method in disc, well, and agar dilution in various concentrations. Minimum inhibitory concentration (MIC) and minimum fatal concentration (MFC) were also determined. Aspergillus, Penicillium, Cladosporium, and Acremonium fungi were the most commonly found fungal contaminants of this investigation. Antifungal activity was not observed by disc diffusion and well diffusion methods. In the agar dilution method, ethanolic and methanolic extracts of stem and leaves in concentrations of 80, 60, 40, and 30 mg/ml, and ethanolic and methanolic extracts of plant bulbs in concentrations of 60 and 30 mg/ml revealed antifungal activity against Aspergillus niger, Penicillium notatum, and Penicillium chrysogenum. The MIC of stem and leaf ethanol extracts and onion ethanol for Aspergillus niger was 18.7, and for Penicillium notatum and Penicillium chrysogenum, it was 37.5, 37.5, 37.5, and 37.5 mg/ml. Fungal contamination of dairy products is a serious threat to the public health of society. Therefore, identifying medicinal plants with antifungal activity can be an effective step in preventing fungal contamination and increasing the shelf life of these products. The results of this research have shown that the Allium jesdianum plant can inhibit the growth of Aspergillus niger, Penicillium notatum, and Penicillium chrysogenum.

Health risk assessment of lead and cadmium in milk-based products of Iran

The primary objective of this study is to assess the health risks associated with lead (Pb) and cadmium (Cd) contamination in dairy products consumed in Iran. To conduct the research, 132 samples of cow milk, yogurt, cream, and doogh (a traditional Iranian beverage) were collected from both traditional and industrial livestock farms in Zanjan, Iran. The samples were microwave-digested, and an atomic absorption spectrophotometer equipped with a graphite furnace was used to determine toxic metals contents. The findings of the study revealed that the average concentrations of Pb in milk and dairy product exceeded the permitted limits. The mean ± se levels of Pb and Cd in milk, yogurt, doogh, and cream were 92.64 ± 8.73, 52.19 ± 8.42, 78.80 ± 12.89, 106.07 ± 8.94 μg/kg and 2.34 ± 0.22, 1.21 ± 0.20, 2.59 ± 0.57, 5.61 ± 0.63 μg/kg, respectively. For the purpose of exposure assessment, the chronic daily intake (CDI) was utilized, while the Hazard Quotient (HQ) and Total Hazard Quotient (THQ) were employed for non-carcinogenic risk assessment. Additionally, the Incremental Lifetime Cancer Risk (ILCR) was utilized for carcinogenic risk assessment. The results revealed that the highest exposure to Pb and Cd in the P 95th of CDI were observed in milk, followed by yogurt, doogh, and cream. According to our finding, the HQ and THQ values for potentially toxic elements (PTEs) related to the consumption of dairy products in the P 95th of cumulative probability were below 1. The results indicate that the ILCR of Cd (P 95th) due to the consumption of dairy products falls within the acceptable risk range (10−4 to 10−6). While our findings indicate levels of Cd in dairy products, it is important to note that there are currently no established standards for permissible Cd concentrations in Iran. Therefore, further research and regulatory frameworks are needed to ensure public safety.

Quantification of toxic metals contamination and health risk assessment in processed and raw dairy products in Abbottabad city

Toxic metal contamination (such as Cd, Cr and Pb) in processed and raw dairy products is an important environmental and public health concern. The accumulation of these metals in dairy products causes health threats to consumers. Various anthropogenic and natural activities discharge metals into the soil, where they are consumed by plants and become a part of the food chain. In addition, there is a considerable risk of metal contamination in dairy products during various business processes. The present study was carried out to determine the quantities of toxic metals found in dairy product samples. These dairy products have been classified into two groups: raw dairy products, which were self-extracted from cows and buffaloes employing adequate hygiene, and processed dairy products, which were bought from the Abbottabad market. These samples were generated using a double acid digestion approach, and toxic metals were quantified using atomic absorption spectrophotometry (AAS). For health risk assessment, the Health Risk Index (HRI), Target Hazard Quotient (THQ), and the Target Cancer Risk (TCR) indices were used. The relative levels of toxic metals in processed dairy product samples were as follows: Cd levels were highest in cheese (0.106±0.006 mg/kg), followed by butter and desi ghee (0.089±0.066 and 0.074±0.043 mg/kg, respectively). Cr concentrations were maximum in flavored milk (0.471± 0.290 mg/kg) and desi ghee (0.371± 0.01 mg/kg). Pb levels found in cheese were higher (1.753±0.194 mg/kg), then desi ghee and butter (1.025±0.01 and 0.652±0.397 mg/kg, respectively). Toxic metals in raw dairy products were measured in cow samples in the order of Cr ≥ Pb ≥ Cd. In a similar manner for buffalo samples, toxic metals followed the same trend as in cow samples. Though the concentrations of targeted metals in both raw and processed dairy product samples exceeded the threshold levels, the estimated levels of THQ and TCR were within the permissible range. However, our findings suggest that these metals in dairy products should be assessed on a continuous basis, as anthropogenic activities are contributing substantially to metal contamination.

Immunogenic Consideration of a Designed Polypeptide Against Brucellosis Compared to RB51: An In Vivo Study.

Brucellosis in livestock and its transmission to humans through the consumption of contaminated dairy products is an important issue. The introduction of new approaches using immunogenic proteins against and diagnosing brucellosis is a serious issue in human health. Brucella abortus contains five proteins including: MOXR family ATPase-α2, T9SS C-terminal target domain-containing protein, Cobyric acid synthase, Hypothetical protein, and VirB11 type IV Secretion protein, which were considered and the designed recombinant polypeptide was produced and evaluated. The pure recombinant protein ABOR with 549aa in combination with chitin as an adjuvant was injected subcutaneously into guinea pigs to evaluate their immunity responses. The results indicated that the ABOR recombinant protein induced Th1 immunity with high levels of specific IgG (IgG2a) as well as Interferon-γ (IFN-γ), Interleukin-2 (IL-2), IL-12, and Tumor Necrosis Factor-alpha (TNF-α), compared to the control group. Th1/Th2 ratio analysis demonstrated the efficacy of ABOR protein combined with chitin in stimulating cellular immunity in the animals. Designed recombinant polypeptide combined with chitin showed ability for induction of cellular and humoral immunity an guinea pigs compared to RB51 vaccine.

Geographical distribution of caudatoside and ptaquiloside in bracken ferns in Northern Europe

Bracken ferns (genus Pteridium) are among the most prevalent plants worldwide, with their distribution expanding due to their invasive nature. The environmental implications of their proliferation in areas affected by human activity, natural disasters, or land-use changes are concerning, primarily because of the carcinogenic illudane glycosides they produce. These compounds cause domestic and wildlife animal poisoning, as well as contamination of dairy products and drinking water. Several illudane glycosides are known, but usually only ptaquiloside (PTA) is monitored. This study investigates the spatial and temporal variations in illudane glycosides PTA, caudatoside (CAU) and ptesculentoside (PTE) across two phenotypes of Pteridium aquilinum (vars. aquilinum and latiusculum) over a broad geographic range spanning Denmark, Sweden, and Finland, encompassing 66 locations. We analysed different parts of the fern fronds (the tips and the lowest pinnae) using LC–MS and statistically explored the influence of phenotype, frond part, geographic location, sunlight exposure, and the surrounding ecosystem on glycoside content. Our findings reveal that PTA accounts for approximately two-thirds of the total illudane glycoside content, followed by CAU at nearly one-third, and a minor contribution from PTE. Glycoside levels were not influenced by phenotypic varieties or the studied environmental factors, but were significantly affected by geographic location. Specifically, CAU levels increased progressively towards the northeast, while PTA concentrations were highest in Denmark and markedly decreased in northeastern countries by over threefold, presumably due to climatic gradient. It has been further supported by temporal analysis in selected PTA-dominant regions indicating a reduction in PTA towards the end of the growing season, aligning its levels with those of CAU. Our study highlights that CAU concentrations in bracken ferns may equal or surpass PTA, contesting the prevailing view that PTA is the only notable illudane glycoside in Bracken. To provide unbiased assessment of the potential risks posed by P. aquilinum in the region, environmental and toxicological research should include measurements of not only PTA, but also CAU and, if possible, PTE.

Spatial and Bioaccumulation of Heavy Metals in a Sheep-Based Food System: Implications for Human Health.

Heavy metal contamination in agricultural soils presents serious environmental and health risks. This study assessed the bioaccumulation and spatial distribution of nickel, cadmium, zinc, lead, and copper within a sheep-based food chain in the Baia Mare region, Romania, which includes soil, green grass, sheep serum, and dairy products. Using inductively coupled plasma mass spectrometry (ICP-MS), we analyzed the concentrations of these metals and calculated bioconcentration factors (BCFs) to evaluate their transfer through trophic levels. Spatial analysis revealed that copper (up to 2528.20 mg/kg) and zinc (up to 1821.40 mg/kg) exceeded permissible limits, particularly near former mining sites. Elevated lead (807.59 mg/kg) and cadmium (2.94 mg/kg) were observed in industrial areas, while nickel and cobalt showed lower concentrations, but with localized peaks. Zinc was the most abundant metal in grass, while cadmium transferred efficiently to milk and cheese, raising potential health concerns. The results underscore the complex interplay between soil properties, contamination sources, and biological processes in heavy metal accumulation. These findings highlight the importance of continuous monitoring, risk assessment, and mitigation strategies to protect public health from potential exposure through contaminated dairy products.

A novel K57-specific Klebsiella pneumoniae phage disinfects milk and inhibits biofilm formation

Klebsiella pneumoniae (K. pneumoniae), especially serotype K57, is a major pathogen in dairy bovine mastitis, causing significant economic losses and posing a public health risk through contaminated dairy products. In addition, K57 is highly virulent among serotypes infecting humans, leading to serious conditions such as pyogenic liver abscess. In this study, we isolated and identified a bacteriophage called vB_Kp_Z57 that targets K57 serotype K. pneumoniae isolates from human and bovine sources. The phage has a latent period of 4 min and can produce approximately 233 phages per infected bacterial cell. vB_Kp_Z57 is stable over a temperature range of 4 °C to 60 °C and a pH range of 5–11. Sequencing and assembly of the phage genome revealed DNA molecules consisting of 40,316 base pairs. After genome annotation with bioinformatics software, it was discovered that the phage genome encodes 48 proteins, with no detected lysogeny genes, toxin genes, or tRNA-related genes. vB_Kp_Z57 was classified as a member of genus Przondovirus, family Autographiviridae. The results of bacteriostatic experiments show that vB_Kp_Z57 has a good effect on inhibiting bacterial growth. Notably, vB_Kp_Z57 significantly inhibited the growth of its host bacteria in milk at refrigerated temperatures of 4 °C and room temperature. Biofilm inhibition experiments revealed that phage vB_Kp_Z57 significantly reduced OD595 values in all phage-treated groups, indicating its potential as an effective biocontrol agent against K. pneumoniae. Our findings show the promise of vB_Kp_Z57 as a novel and environmentally friendly solution to address the challenges associated with K. pneumoniae in dairy production.

A spectroscopy-based proof-of-concept (POC) for developing loading of pathogen analyzer (LOPA) for dairy products

Detection of bacterial contamination in dairy products of daily use is a challenge worldwide. We have utilized Methylene Blue Reduction Test (MBRT) for quantification of the microbial count in dairy products (milk) and developed a proof-of-concept (POC) based on this for in-filed applications. In this study, we have used pasteurized milk contaminated with model bacteria Escherichia coli, and Staphylococcus aureus for the calibration and validation of the developed POC. The conversion of MB to Leuco-MB i.e., the colorimetric change due to the reduction of MB to Leuco-MB in presence of microbes has been utilized as the tool to detect presence of microbes in milk. The absorbance peak for methylene blue (MB) at 664 nm decreases significantly in presence of microbes and the blue color becomes faded. In our study, we have employed methylene blue (MB) discolouration phenomenon to estimate the microbial count in milk samples using our developed spectroscopy based POC. The limit of detection (LOD) and the limit of quantitation (LOQ) of the POC were found to be 0.32 CFU/mL and 0.97 CFU/mL. The end users of the developed POC are primarily those involved in the production, processing, testing, regulation, and research of dairy products to ensure they meet safety standards and protect public health. These include retailers, dairy farmers, dairy processors, quality control laboratories, regulatory agencies and research institutions. In our experiment, we have observed a significant change in MB absorption in the milk contaminated with microbes. The indigenously developed sensor strips designed for the working of the POC turn to colorless Leuco-MB compared to milk without the microbes. The analysis of the strips has been measured in the developed device.

The Prevalence of Brucella Spp. in Dairy Products in Iran: A Systematic Review and Meta-Analysis.

Brucellosis, a significant zoonotic disease, threatens food safety substantially, particularly in developing nations such as the Middle East. This study aimed to comprehensively assess the prevalence of Brucella spp. in Iranian milk and dairy products through a systematic review and meta-analysis. A thorough search of international and domestic databases from January 2008 to October 2023 identified 38 relevant studies encompassing 11,130 samples for meta-analysis. The overall prevalence of Brucella spp. in Iranian dairy products was 22% (95% CI: 16-28%). The highest and lowest overall prevalence of Brucella spp. in milk were found in raw goat milk 27% (95% CI: 11-42%) and raw camel milk 15% (95% CI: -0.42 to 72%), respectively. The overall prevalence of traditional cheese, ice cream, and cream is estimated to be 9% (95% CI: -16 to 35%), 2% (95% CI: -2.78 to 2.82%), and 9% (95% CI: -0.94 to 1.12%). Geographical disparities were evident, with Zanjan province reporting the highest contamination rate, 53%, while Razavi Khorasan province had the lowest, 1%. However, the prevalence of Brucella spp. in Iranian dairy products has fluctuated over time, with a significant association between the study year and sample size. Comprehensive planning, robust policy implementation, and rigorous monitoring are imperative to mitigate and ultimately eliminate Brucella contamination in dairy products effectively. Further research is essential to refine prevalence estimates and develop targeted prevention strategies to safeguard public health.

Seroprevalence of Brucella among Patients Visiting a Single-Center Hospital: A Cross-Sectional Study

Introduction: Brucellosis is a disease that can be contracted by humans through contact with infected animals or animal products. It can be transmitted through contaminated dairy products, so caution must be exercised when handling and preparing food. By taking precautions, the spread of this disease can be mitigated to protect both humans and animals. (1) Brucella spp is a type of bacteria that can cause an infection. The symptoms of this infection can range from mild flu-like symptoms to severe complications that affect different parts of the body. Because Brucella is able to invade the body and avoid the immune system, it's important to get an accurate diagnosis and start treatment as soon as possible. (2). (3)  Method: The study was conducted at Kalkaal Hospital from 2019 to 2023, spanning three years. Patients who went to the hospital's Outpatient department and were screened for Brucella were included in the study. Data on patients' demographics, including their residence, gender, age, and Brucella screening results, were collected and recorded over the study period. The participants' blood samples were gathered and analyzed for Brucella infection through a variety of diagnostic The clinical assessment included an examination of symptoms, medical history, and possible exposure to Brucella. To detect specific antibodies (IgM and IgG) against Brucella present in the blood serum, serological tests such as the Serum Agglutination Test (SAT), ELISA, and Rose Bengal Test were conducted. The blood samples were analyzed to identify the Brucella bacteria through blood cultures. In addition, the presence of Brucella DNA was confirmed in various clinical samples using Polymerase Chain Reaction (PCR). The Kalkaal Hospital Research Review Board gave approval for the study protocol. Data cleaning was carried out with the help of Excel. The analysis of data was performed using SPSS software version 25.  Results: According to the analysis of the data, 30.3% of patients were men, and 69.7% of patients were women. The age ranges were 0–19: 1245 (8.1%), 20–29: 3951 (25.7%), 30-39: 3027 (19.7%), 40–49: 1786 (11.6%), and 50+: 4582. (29.9 percent). In addition, 14884 (97.0%) of the outcomes were negative, while only 465 (3.0%) were positive.  Conclusion: The research carried out at Kalkaal Hospital in Mogadishu, Somalia, has revealed important information about the prevalence of Brucella infection in the area. The results suggest that a significant number of patients have tested positive for Brucella antibodies, which indicates that the disease is a significant burden on the local population. These findings add to the global knowledge of brucellosis and emphasize its severe and long-term effects. It is important for experts in this field to have further discussions and come to a consensus on how to address this issue.

Epidemiological Analysis of Childhood Brucellosis in Duhok, Iraq: A Retrospective Observational Study From 2018 to 2021.

Brucellosis is a zoonotic disease that can spread from animal to human through contaminated dairy products, raw vegetables, and water or via direct contact with infected animal tissues. While the disease affects individuals of all ages, research on its prevalence and clinical profile, particularly in Iraq, is limited. To address this knowledge gap, a retrospective observational study was conducted using data from the Bacterial Serology Laboratory of Heevi Pediatric Teaching Hospital, Duhok, Iraq, from 2018 to 2021. Of the 1,032 suspected cases of brucellosis in children, 72 cases that met the inclusion were analyzed. The study found a 7% prevalence of childhood brucellosis in the Duhok region, with the highest incidence of 7.8% in 2020. The infection rate was age-dependent, with most cases occurring in the year's third quarter. No statistically significant relationship was found between sex and the infection rate. These findings highlight the importance of targeted public health interventions and improved diagnostic protocols to reduce the prevalence of brucellosis among children in this region.

A multicriteria assessment of food safety measures for a large dairy farm in hot weather conditions

Dairy farms are vulnerable to the impacts of climate change through the alteration of raw milk quality and pressure on animal health. Measures in dairy farms are necessary to reduce microbiological risks that may impact animal health and may be passed on to humans through the consumption of contaminated dairy products. However, these additional controls should incur lower environmental impact, have a low cost of implementation, minimal impact on milk property, and sufficient effectiveness to control risks. This study selected a dairy farm located under hot weather conditions to demonstrate how these challenges may be considered. Our objective was to present how a multi-criteria decision analysis (MCDA) could be used to select the appropriate mitigation strategy for this farm among fifteen potential food safety measures.The MCDA framework brought together ten criteria classified into four supra criteria: stakeholder acceptance, food safety effectiveness, environmental impact, and impact on milk properties. The relative performances of various food safety measures scored against the ten criteria were expressed either in qualitative or quantitative values. Ultimately, the outranking MCDA technique, PROMETHEE II, was used to rank the measures.This study ranked the selected four food safety measures, namely, sand bedding, chitosan supplementation, cooling mister operation, and phage spray, after a series of preselection filters. It was found that none of these dominated the others on the ten criteria. However, MCDA has allowed the determination of the best compromise among the selected measures. It was found that an increase in the frequency of changing the sand bedding ranked first, and an increase in the operation of cooling misters was ranked last.The study demonstrated the benefit of MCDA in combining criteria of different nature (stakeholder acceptance, food safety effectiveness, environmental impact, milk properties), values, and scales to prioritize food safety measures. The approach can be applied to other dairy farms eager to limit the impacts of climate change while guaranteeing food safety.

Aflatoxins in maize, milk and dairy products from Serbia

ABSTRACT This study presents data on the occurrence of aflatoxins B1, B2, G1 and G2 in maize and aflatoxin M1 (AFM1) in milk and dairy products from Serbia in 2022. A total of 100 maize samples were analysed using liquid chromatography tandem mass spectrometry, while 107 cow and goat milk, besides dairy products were tested with an ELISA method. Aflatoxins contaminated 78% of the maize samples, with aflatoxin B1 as the most prevalent aflatoxin, also at the highest determined level. All milk samples tested positive for AFM1, while contamination in dairy products ranged from 14% to 100%. The hot and dry weather during the 2022 maize growing season, characterised by moderate to extreme drought conditions, significantly increased maize contamination with aflatoxins, impacting subsequent milk and dairy products contamination. The findings of this study confirm the continuous trend and persistent challenge in Serbia concerning the prevalence of aflatoxins in maize and milk, closely linked to climate change.

Contamination of dairy products with tris(2,4-di-tert-butylphenyl) phosphite and implications for human exposure

Tris(2,4-di-tert-butylphenyl) phosphite (AO168), an organophosphite antioxidant, can be oxidized to tris(2,4-di-tert-butylphenyl) phosphate (AO168 = O) during the production, processing, and application of plastics. AO168 = O can be further transformed to bis(2,4-di-tert-butylphenyl) phosphate and 2,4-di-tert-butylphenol. Here, we discovered the contamination of AO168 and its transformation products in dairy products for the first time. More samples contained AO168 (mean concentration: 8.78 ng/g wet weight [ww]), bis(2,4-di-tert-butylphenyl) phosphate (mean:11.1 ng/g ww) and 2,4-di-tert-butylphenol (mean: 46.8 ng/g ww) than AO168 = O (mean: 40.2 ng/g ww). The concentrations of AO168 and its transformation products were significantly correlated, and differed with the packaging material and storage conditions of the product. Estimated daily intakes (EDIs) of AO168 and its transformation products were calculated. Although the overall dietary risks were below one, transformation products accounted for 96.7% of the total hazard quotients. The high-exposure EDIs of total AO168 were above the threshold of toxicological concern (300 ng/kg bw/day), and deserve continual monitoring.

Importance of Rigorous and Ongoing Monitoring of Animal Feed Quality and Storage Conditions to Mitigate Aflatoxin M1 Contamination in Dairy Products in Iran: A Health Policy Brief

Background: Milk and dairy products are essential for global nutrition, and ensuring their safety is crucial. Aflatoxin M1 (AFM1), a carcinogen from contaminated animal feed, poses a significant threat to consumers. Objectives: This “health policy brief" highlights the critical need for meticulous and constant monitoring of Iran's animal feed quality and storage conditions to minimize AFM1 contamination in dairy products. Methods: Comprehensive review papers on AFM1 were reviewed in Iranian dairy products, drawing evidence from various databases. Results: The prevalence of AFM1 contamination in Iranian dairy products, particularly risky for children due to extensive consumption, exceeds safety limits, with livestock feed identified as the primary source. Public health demands rigorous monitoring practices, such as stricter feed quality and storage regulations, regular AFM1 testing, stakeholder collaboration, and public awareness. There are many benefits associated with these measures, including lowering AFM1 levels in dairy products, improving food safety standards, minimizing AFM1 exposure risks, especially for children, and increasing consumer confidence in the integrity of the Iranian dairy industry. Conclusions: Continuous monitoring of animal feed is crucial to safeguard public health and ensure the safety of Iranian dairy products, particularly for children. This comprehensive approach, collaboration, and public awareness are vital to mitigating AFM1 contamination and promoting Iran's safe and robust dairy industry.

Microbial risk assessment of dairy products from retail marketplaces in Basrah province, Iraq.

Milk-borne bacteria cause degradation of milk products and constitute a significant risk to public health. The objectives of the present study are to determine the microbiological quality of dairy products and to investigate pathogenic microorganisms. A total of 60 samples of raw milk, homemade cheese, and yogurt were randomly selected from different retail marketplaces in Basrah. The bacteriological and biochemical tests were utilized to identify the pathogens in dairy samples, as well as the molecular technique was used as an accurate diagnostic test. The prevalence of contamination of milk products with various isolates was estimated as 50% (95% Cl: 36.8-63.2). The mean of total bacteria count for cheese was 7.29 ± 2.70, raw milk 4.62 ± 2.86, and yogurt 2.87 ± 1.05, with a significant p-value (p = 0.001). The mean count of aerobic spore-forming (ASF) contaminated raw milk was analyzed as 3.77 ± 1.18 and less contamination detected in the yogurt samples with mean of ASF was estimated as 2.52 ± 1.47 SD log 10 CFU/ml. A range of important microorganisms to human health were identified by employing the VITEK_2 system and sequencing 16S rDNA gene, including Staphylococcus aureus, Escherichia coli, Pseudomonas aerogenosa, and Bacillus cereus. The study indicates that there is a high level of bacterial contamination in dairy products with different bacteria species, which is medically important. Therefore, food safety management must be implemented to reduce biological risks carried by dairy products and ensure healthy food for consumers.

MAIN TECHNOLOGICAL CHARACTERISTICS OF COW’S MILK IN ACCORDANCE WITH EU REQUIREMENTS

The study is focused on considering the issues of harmonization of domestic standards in accordance with EU requirements, the importance of studies of the quality of cow’s milk in relation to microbial contamination, and the informational capabilities of the indicator of the number of somatic cells in milk. It is outlined that the production of milk in Ukraine has decreased over the last decade, nevertheless, an increase in the average annual milk yield per cow is being monitored, which indicates improvement in the genetic material. The normative documents establishing requirements for the quality of milk and dairy products in accordance with European standards, in particular, for indicators of total bacterial insemination, number of somatic cells, freezing point, fat and protein percentage, were considered. The mentioned indicators in the leading countries for the production of dairy products and the peculiarities of determining its quality were analyzed, in particular, in relation to psychrotrophic microflora. In this sense, the temperature range of contamination of milk by bacteria of various types is given. The main sources and the share of their impact on milk contamination, which spreads through the internal and external environment, are established in the study, as well as the means of their avoidance are indicated. The sanitary condition of milking equipment, the speed and quality of milk cooling after milking (in general, about 70%) have the greatest influence on the contamination of dairy products. Important influencing factors are proper care of the udder, the condition of the floor, the sanitary and hygienic condition of the location of the animals, feed, water, air in the premises, as well as the labour hygiene of the workers on the dairy farm. The important indicator of milk quality is the content of somatic cells, which is the main indicator of infection in the animal’s body and makes it possible to identify cows with mastitis in time. Regular control of the content of somatic cells in milk is especially important during the subclinical course of mastitis. In this sense, it is promising to use express methods of mastitis diagnosis, to establish relationships between the synthesis of milk components and the physiological state of the cow, to determine the genetic determinant of the sensitivity of cows to mastitis pathogens, and therefore to prevent mastitis by targeted selection of animals.

A review of the stability of antibiotic residues in animal products during food processing

Residues of antimicrobials in food have received much attention in recent years because of growing food safety and public health concerns. The ingestion of veterinary drug residues in edible animal parts and contaminated dairy products constitutes a potential health hazard for its consumers, including, specifically, the possibility of developing multidrug resistance, carcinogenicity, and disruption of intestinal normal microflora. Therefore, the aim of the study was to review the stability of food processing on the antibiotic residues in animal products. We have seen that different cooking procedures, heating temperatures, storage times (cooling and freezing), fermentation, and pH have the significant reduction of drug residues in animal products. Several studies have reported the use of thermal treatments and sterilization to decrease the quantity of antibiotics such as tetracycline, oxytetracycline, macrolides, sulfonamides, azithromycin, chlortetracycline, and doxycycline in animal products. The presence of antibiotic residues in raw milk samples is more than prescribed limits by international regulations, leading to inhibition of growth of starter microorganisms during manufacturing processes of dairy products. Time and temperature of heating, freezing degree, medium pH, and antibiotic type were the most important factors the effect on the stability of the antibiotic residue in food products.

Resultado de pesquisa global sobre resistência antimicrobiana na pecuária leiteira

ABSTRACT Antimicrobials are pivotal in treating bacterial infections. More often than any other class of antimicrobial, antibiotics are a class of antimicrobials used primarily to treat bacterial infections. Thus, both human health and life longevity, as well as the welfare of animals, have greatly improved with the development of antibiotics as a means of treating infectious diseases. Dairy farming is essential to satisfying the world's demand for dairy products. Nevertheless, improper use of antibiotics in dairy farming contributes greatly to the formation of antimicrobial resistance. Moreover, the resulting antimicrobial resistance can be transferred to humans by consuming contaminated dairy products. Therefore, the scientific community has been intensively studying the relationship between dairy farming and antimicrobial resistance since 1983. And, due to the increasing awareness of antimicrobial resistance worldwide, studies on antimicrobial resistance in dairy farming have rapidly increased 89 times in the last twenty years. Today, the development of antimicrobial resistance in dairy farming is among the trending research topics. For this purpose, this study is the first bibliometric approach that aims to guide future studies by revealing all aspects of the studies on this subject between 1983 and 2023.