scholarly journals THE DEVELOPMENT OF THE METHOD FOR THE DETERMINATION OF SULFONAMIDES AND TRIMETOPRIM RESIDUAL QUANTITIES IN MILK SAMPLES BY UPLC-MS/MS METHOD AND ITS VERIFICATION THROUGH INTERLABORATORY TESTING

2020 ◽  
Vol 21 (2) ◽  
pp. 170-182
Author(s):  
M. Rydchuk ◽  
S. Plotycya ◽  
D. Yanovych ◽  
Z. Zasadna ◽  
S. Kislova ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Dairy Products ◽  
Milk Powder ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Milk Samples ◽  
Powder Samples ◽  
Tandem Mass Spectrometric ◽  
Fast Procedure

This manuscript presents the results of development and adoption of the confirmatory UPLC- MS/MS method for determination of sulfonamides and trimethoprim residues in whole and powdered cow's milk samples. Sample preparation includes a recovery with water (in the case of milk powder), separation of milk fat by centrifugation at 4 °C, proteins precipitation with acetonitrile using ultrasonic intensification, extraction of analytes with a two-component mixture of organic solvents from weak acidic phosphate buffer solution, concentration of obtained extracts, degreasing and reconstitution with the mobile phase. The use of tandem-mass spectrometric detector in multiple reaction monitoring mode provides high specificity for all ten sulfonamides, which molecules contain the same structural elements, and trimethoprim, as three ion transitions were used for each of the target analytes. The approach of matrix matched calibration on the milk matrix was applied, and it allowed us to disregard taking into consideration the absolute extraction of analytes during sample preparation, as well as the influence of sample matrix components on analytes ionization. The main advantages of the developed technique are simplicity, rapidity and cost effective sample preparation, fast procedure of sample analysis (the time of chromatographic separation is 2.0 min), high selectivity, and sensitivity at the level of ≤ 0.5 μg/kg (as compared with the maximum residues level of sulfonamides in dairy products, viz. 100 μg/kg). According to the European Commission Decision 2002/657/EC, the values of CCα and CCβ for sulfonamides and trimethoprim in milk were calculated. The capability of the method was confirmed on the basis of the established validation parameters, using spiked milk samples and "added – found" approach. The method was tested during the analysis of spiked samples of whole and powdered cow's milk (CV ~ 20%). The developed technique was verified by interlaboratory comparative testing of milk powder samples for sulfonamides content. The UPLC-MS/MS method for the determination of sulfonamides and trimethoprim residues in whole and milk powder samples can be used both for routine laboratory analysis of dairy products and for the examination of suspicious or questionable samples.

scholarly journals Effect of an Italian propolis on the growth of Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus in milk and whey cheese

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Francesca Pedonese ◽  
Giada Verani ◽  
Beatrice Torracca ◽  
Barbara Turchi ◽  
Antonio Felicioli ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Dairy Products ◽  
Skim Milk ◽  
Cow’S Milk ◽  
Alcoholic Extract ◽  
Cow's Milk

Propolis antimicrobial activity has been limitedly studied in food, particularly in dairy products. We studied the antimicrobial activity of an alcoholic extract of an Italian propolis in sterile skim milk, pasteurized cow’s milk, and cow’s and goat’s whey cheese (ricotta). Following the determination of the minimal inhibitory concentration on Gram+ and Gram- bacteria, the extract was employed at 2 and 5% (P2, P5), using controls with the same ethanol concentrations (E2, E5) and without any addition. In milk trials, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Pseudomonas fluorescens were tested. P2 and P5 samples registered significant decreases of Gram+ bacteria in skim milk. The same was true for P5 in cows’ milk, but only with S. aureus for P2. Ricotta was inoculated with L. monocytogenes, S. aureus and B. cereus and stored at 8.5°C. In cow’s milk ricotta, L. monocytogenes counts in P5 were always lower than control during the storage time, significantly so from the 14th day. In goat’s ricotta, L. monocytogenes counts in P5 were at least one logarithm lower than E5, whereas the extract didn’t show a significant effect on S. aureus and B. cereus. The antimicrobial activity of propolis, particularly on L. monocytogenes, could be employed in ready-to-eat refrigerated dairy products.

A survey on the occurrence of aflatoxin M1 in raw milk samples in Bafq and Bahabad, Iran

2021 ◽  
Author(s):  
Vahid Safavizadeh ◽  
Mozhgan Mojkar
Keyword(s):  
Aspergillus Parasiticus ◽  
Raw Milk ◽  
National Standard ◽  
Aflatoxin M1 ◽  
Cow’S Milk ◽  
Elisa Method ◽  
Cow's Milk ◽  
Milk Samples ◽  
The City

Aflatoxins are a group of mycotoxins mostly produced by the fungi called Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomium. Aflatoxin M1 (AFM1) is the major metabolite of aflatoxin B1 and is a hepatotoxic and carcinogenic toxin. The aim of this study was to determine the level of contamination of cow's milk with aflatoxin M1 in Bafq and Bahabad. For this study, samples of raw cow's milk were collected randomly from milk collection centers around the city of Bafq and Bahabad from March to April. The determination of aflatoxin M1 levels was based on the ELISA method. Contamination was observed in 100% of milk samples. According to the results of the study, the rate of contamination with aflatoxin M1 in 43.3% of milk samples was above the acceptable level (50 ng/L) in Iranian national standard. It is concluded that further monitoring of milk production should be carried out in the spring and winter seasons.

scholarly journals Determination of the Level of Heavy Metals in Cow’s Milk Collected from Butajirra and Meskan Districts, South Central Ethiopia.

2021 ◽  
Author(s):  
Amha Teklu Asayehegn ◽  
Ariaya Hymete ◽  
Seifu Hagos ◽  
Ayenew Ashenef
Keyword(s):  
Heavy Metals ◽  
Microwave Digestion ◽  
The Body ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Milk Samples ◽  
Lactating Cows ◽  
Chemical Hazards ◽  
South Central

Abstract BackgroundMilk is a complete food useful to promote growth and development of the infant mammals as it contains vital nutrients including proteins, essential fats, vitamins, and minerals, in a balanced proportion. Milk can also contain chemical hazards and contaminants, such as heavy metals which can be a risk for health. This study was aimed at determining the level of the heavy metals in cow’s milk collected from Butajirra and Meskan districts, south Ethiopia. Cows’ milk was collected from 193 healthy and lactating cows. Samples were digested by optimized microwave digestion method using HNO 3 and H 2 O 2 . Analysis was done using ICP-OES for Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn. MP-AES was used for Ca, Mg, K and Na. ResultsNi was not detected in all the milk samples. The concentrations of metals in the studied milk samples were, Cd (0.0 – 0.03), Cr (0.0 – 0.4), Cu (0.03 – 1.1), Fe (0.0– 1.9), Mn (0.0– 0.7), Pb (0.0– 12.3), Zn (0.0–8.2), Ca (380.1– 532.4), Mg (159.6– 397.9), K (1114.2–1685.8) and Na (495.9–1298.3) ppm. These values were compared with guide lines of different international organizations for food and other available literatures. Cd, Cr, Cu, Mn, Pb, Zn and Mg were found over the permissible limits. ConclusionSpecial attention should be given to the level of heavy metals in cows’ milk, since they are difficult to remove from the body and are dangerous to health once they accumulate to a level greater than their limit.

scholarly journals Staphylococcus aureus of raw cow's milk

2021 ◽  
Vol 23 (102) ◽  
pp. 53-59
Author(s):  
M. D. Kukhtyn ◽  
Y. V. Horiuk ◽  
V. Z. Salata ◽  
V. T. Klymyk ◽  
N. M. Vorozhbit ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Raw Milk ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Milk Samples ◽  
Before And After ◽  
Pure Cultures ◽  
Almost All

The presence of Staphylococcus aureus in raw milk is considered a direct danger to consumers. Almost all types of dairy products normalize the amount of Staphylococcus aureus in 1 g (cm3) of product, due to their ability to produce thermostable enterotoxins. The aim of the study was to investigate the role of incision of teats of healthy and sick mastitis cows and milking equipment for irradiation of cow's milk with Staphylococcus aureus. Sanitation of milking equipment in farms was carried out with alkaline detergents based on sodium hypochlorite and acid based on phosphoric acid. Blood agar with 5 % sodium chloride was used to isolate staphylococci from washes and milk. Species identification of pure cultures of staphylococci was performed using RapID Staph Plus kits. At the same time before and after milking the skin of teats with Udder Wash and Udder Forte reduces the incidence of Staphylococcus aureus to 4.1 ± 0.3 % of cases. Quantitative determination of staphylococci, including golden on the skin of the teats revealed a decrease in the latter from 283.5 ± 21.2 to 27.6 ± 2.1 CFU/cm3 flush after milking. It has been established that the number of staphylococci, including golden, on the skin of teats increases sharply under subclinical or clinical ointment. Thus, it was found that in the subclinical form of staphylococcal mastitis from the skin of teats isolated S. aureus in the amount of 790.6 ± 65.4 CFU/cm3 of wash. At the same time, in the clinical form of mastitis, the amount of S. aureus increased, on average to 8 thousand CFU/cm3 of flush. It was found that under the condition of sanitary treatment of milking equipment with alternate use of alkaline and acid detergents and disinfectants, only 25 % of washes were staphylococci, and gold – up to 5 % of samples. It was found that in 43.7 ± 3.9 % of raw milk samples Staphylococcus aureus was not detected in 1 cm3. The number of milk samples containing Staphylococcus aureus up to 100 CFU/cm3 was 39.1 ± 3.3 %, and 17.2 ± 1.4 % of milk samples were contaminated with Staphylococcus aureus in the amount of 101 to 200 CFU/cm3. Therefore, the presence of more than 200 CFU/cm3 in freshly milked Staphylococcus aureus in milk indicates the ineffectiveness of antimastitis measures, skin remediation of teats and sanitation of milking equipment.

scholarly journals Determination of some minerals and heavy metal levels in Urfa cheese and cow's milk

2021 ◽  
Vol 7 (3) ◽  
pp. 185-193
Author(s):  
Serap Kılıç Altun ◽  
Mehmet Emin Aydemir
Keyword(s):  
Heavy Metal ◽  
Cow Milk ◽  
Cow’S Milk ◽  
Cow's Milk ◽  
Milk Samples ◽  
Icp Ms ◽  
Metal Contents ◽  
Metal Levels ◽  
Retail Outlets

This research was carried out to determine the levels of some minerals and heavy metals in Urfa cheeses and cow's milk offered for sale in Şanlıurfa. Mineral and heavy metal levels were determined by analysing 18 Urfa cheese and 21 cow milk samples collected from retail outlets with ICP-MS. Mean mineral and heavy metal contents in Urfa cheese samples were; magnesium (Mg) 129.8 ±31.14 mg/kg, calcium (Ca) 2712.66 ±1002.4 mg/kg, potassium (K) 272.06 ±127.21 mg/kg, titanium (Ti) 7.48 ±2.63 mg/kg, zinc (Zn) 40.4 ±16.33 mg/kg, selenium (Se) 10.6 ±3.51 mg/kg. In cow milk samples, average selenium (Se) 0.22 ±0.04 mg/kg, titanium (Ti) 0.07 ±0.009, mg/kg, copper (Cu) 0.0068 ±0.01 mg/kg and chromium (Cr) was detected at the level of 0.019 ±0.001 mg/kg. Arsenic (As), cadmium (Cd), lead (Pb) and thallium (Tl) levels were below the detectable levels in Urfa cheese and cow's milk samples. As a result, it was concluded that the samples do not pose a significant danger to public health in terms of heavy metal pollution and can contribute significantly to nutrition with the mineral substances it contains.

Evaluation of Sample Preparation Methods for the Determination of Ca, Cu, Fe, K, and Na in Milk Powder Samples by ICP-OES

2015 ◽  
Vol 9 (3) ◽  
pp. 777-784 ◽  
Author(s):  
Eliézer Q. Oreste ◽  
Alexander O. de Souza ◽  
Camila C. Pereira ◽  
Meibel T. Lisboa ◽  
Mirla Janaína A. Cidade ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Milk Powder ◽  
Icp Oes ◽  
Preparation Methods ◽  
Powder Samples ◽  
Sample Preparation Methods

scholarly journals Comparative Characteristics of the Amino Acids Composition of Sheep Milk from Breeds of Northern Kazakhstan

2021 ◽  
Vol 9 (3) ◽  
pp. 980-987
Author(s):  
Aknur Muldasheva ◽  
Gulmira Zhakupova ◽  
Dulat Ibrayev ◽  
Aigul Omaralieva ◽  
Zhuldyz Satayeva
Keyword(s):  
Chemical Composition ◽  
Dairy Products ◽  
Milk Protein ◽  
Genetically Modified Organisms ◽  
Milk Powder ◽  
Soviet Period ◽  
Cow’S Milk ◽  
Lactation Period ◽  
Cow's Milk ◽  
Sheep Milk

Kazakhstan is characterized by a wide variety of natural, climatic, economic, and ethnic factors that have a specific impact on the development of sheep farming. The production of dairy products from sheep is limited due to the low productivity of animals and the seasonality of milk production throughout the year, as well as the short lactation period. Also, one of the problems is manual milking of sheep, which does not allow obtaining sheep milk on an industrial scale. The market of dairy products, currently in the Republic of Kazakhstan is represented only by-products made from cow's milk, and at the same time, most of them are products made from cow's milk powder, so the development of products made from sheep's milk is an urgent task. In addition, sheep's milk is a national product, and one of the tasks is to revive the traditional products of the Kazakh people. The analysis of literature studies shows that in-depth studies of the chemical composition of sheep's milk have not been conducted in Kazakhstan. The chemical composition data obtained during the Soviet period only give an idea of the primary chemical parameters obtained by generally accepted basic methods and do not provide reliable information about the deep chemical composition of the milk of local ewes. According to the results of studies, the content of the essential amino acid valine in cow's milk (0.21 g/100g) is also lower than in sheep's milk (9.69-3.79 g/100g). Sheep's milk protein is digested in the human body by 99.1%, and cow's milk protein by 91.9%. According to world experts, one of the advantages of Kazakhstan's domestic milk products is its naturalness, a low share of the use of genetically modified organisms, and environmentally friendly pastures, due to which they receive high-quality and safe products. Therefore, the designated research topic and its analysis are appropriate and relevant.

Human Breast Milk Contains Bovine lgG. Relationship to Infant Colic?

PEDIATRICS ◽  
1991 ◽  
Vol 87 (4) ◽  
pp. 439-444
Author(s):  
Patrick S. Clyne ◽  
Anthony Kulczycki
Keyword(s):  
Breast Milk ◽  
Human Milk ◽  
Milk Protein ◽  
Cow’S Milk ◽  
Human Breast Milk ◽  
Human Breast ◽  
Cow's Milk ◽  
Milk Samples ◽  
Infant Colic ◽  
Β Lactoglobulin

Previous studies have suggested that an unidentified cow's milk protein, other than β-lactoglobulin and casein, might play a pathogenetic role in infant colic. Therefore, a radioimmunoassay was used to analyze human breast milk and infant formula samples for the presence of bovine IgG. Milk samples from 88 of the 97 mothers tested contained greater than 0.1 µg/mL of bovine IgG. In a study group of 59 mothers with infants in the colic-prone 2- to 17-week age group, the 29 mothers of colicky infants had higher levels of bovine IgG in their breast milk (median 0.42 µg/mL) than the 30 mothers of noncolicky infants (median 0.32 µg/mL) (P < .02). The highest concentrations of bovine IgG observed in human milk were 8.5 and 8.2 µg/mL. Most cow's milk-based infant formulas contained 0.6 to 6.4 µg/mL of bovine IgG, a concentration comparable with levels found in many human milk samples. The results suggest that appreciable quantities of bovine IgG are commonly present in human milk, that significantly higher levels are present in milk from mothers of colicky infants, and that bovine IgG may possibly be involved in the pathogenesis of infant colic.

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