No abstract

Fatty acid composition of foods has a great impact on nutrition and health. Therefore, thе determination and knowledge of the fatty acid composition of food is very important for nutrition. Due to the high nutritional characteristics of ostrich meat and its products, the research determining their quality is of topical interest. The aim of the present investigation was the determination of fatty acid composition of ostrich adipose tissue. The content of fatty acids was determined according to AOAC Official Methods of Analysis and determination was performed using a gas chromatograph with a flame-ionization detector (GC-FID). The results are expressed as a percentage of the total content of fatty acids. The method was validated and whereupon the following parameters were determined: linearity, precision, recovery, limit of detection and limit of quantification. The repeatability was within of 0.99 to 2.15%, reproducibility from 2.01 to 4.57%, while recovery ranged from 94.89 to 101.03%. According to these results, this method is accurate and precise and can be used for analysis of fatty acids in foods. It was concluded that the content of saturated fatty acids (SFA) accounted 34.75%, of monounsaturated fatty acids (MUFA) 38.37%, of polyunsaturated fatty acids (PUFA) 26.88%, of total unsaturated fatty acids (UFA) 65.25% and of desirable fatty acids (DFA) (total unsaturated + stearic acid) 70.37% of the analysed samples. The ratio polyunsaturated/saturated fatty acids accounted 0.77. The most present fatty acid is the oleic (C18:1n9c) with 28.31%, followed by palmitic (C16:0) with 27.12% and linoleic (C18:2n6c) acid with 25.08%. Other fatty acids are contained in significantly lower quantities.

A multi-class and multi-residue/contaminant method for the determination of veterinary drug and pesticide residues and mycotoxins in bovine meat has been developed and validated. The veterinary drug residues/contaminants included antimicrobials, anabolic hormones, lactones, β-agonists, mycotoxins, and pesticides. Isotopic labeled internal standards were included to compensate residual matrix effects. The calibrators used in the method demonstrated linearity with the R2 > 0.98. The decision limit (CCα) values were in the range from 0.067 to 2103.84 μg/kg, while the range for detection capability (CCβ) was from 0.083 to 2482.13 μg/kg. The limit of detection (LOD) and limit of quantification (LOQ) were in the range from 0.059 to 291.36 μg/kg, and 0.081 to 328.13 μg/kg, respectively. The recovery of analytes ranged from 61.28% to 116.20%. The intra-day coefficient of variation (CV) was from 0.97 to 25.93% and the inter-day CV was 2.30–34.04%. The method has been used for the determination of 49 residues/contaminants in bovine meat. Application of the method in routine analysis in bovine samples, revealed in limited samples the presences of enrofloxacin, oxytetracycline and sulfadiazine at the concentration of 35.22 µg/kg, 27.35 µg/kg, and 36.20 µg/kg, respectively.

A confirmatory multi-class LC-MS/MS method have been developed for simultaneous determination of 23 antibiotic drugs from seven different classes in bovine milk. The method was validated in accordance with the criteria prescribed in Commission Decision 2002/657/EC. The linear regression analysis showed good correlation with R2 > 0.9800. LOD are in the range of 0.17-6.94 ng/ml, while the LOQ are in the range of 0.50-22.71 ng/ml. The CCα range from 4.43 to 122.33 ng/mL and CCβ was from 4.88 to 139.78 ng/mL. The recovery of the method ranged from 71.96 to 108.70%. The coefficient of variation for repeatability varied from 1.08 to 20.28% and the coefficient of reproducibility varied from 3.14 to 22.88%. In the present study, 189 bovine milk samples were collected from dairy farms and analyzed using confirmatory multi-class LC-MS/MS method. A total of 14 (7.41%) samples were found positive for antibiotics and sulfonamides. The concentrations of the residues were below the maximum levels established by EU.

Background: Acrylamide (AA) is an important food contaminant resulted from Maillard reaction during thermal processing of carbohydrate rich food commodities. The present paper reports the data for the AA content in some types of thermally processed starch rich food, and assessment of dietary exposure for the population in North Macedonia. Methods: The AA level was determined employing modified and validated ultra high performance liquid chromatography with tandem quadrupole detector. A total of 160 samples divided in seven most frequently consumed commodity groups were collected for determination of their AA content. Finally, chronic exposure of AA in the population was estimated. Statistical analysis was performed applying OriginPro 8 SR4 v8.0951 software package Results: The average AA levels varied from 126.9±122.4 μg/kg for bread samples to 494.5±127.1 μg/kg for French fries samples. The dietary exposure of the population from North Macedonia for the tested food commodities was estimated at 0.643±0.171 μgAA/kgbw/day. The main contributor to the total AA intake was bread, with estimated value at 0.394±0.150 μgAA/kgbw/day. The margin of exposure values were 528 and 264, respectively for neurotoxicity and non-plastic effect calculated on average intake. Conclusion: The risk assessment analysis revealed increased concern for human health regarding the neoplastic effects, especially for infants, toddlers, and adolescents. This is the first study related to AA presence in different food commodities in North Macedonia, and implies that monitoring programs and mitigation strategies must be implemented.

Introduction Multi-class and multi-residue analyses are very complex procedures because of the physico-chemical properties of veterinary drug residues and other contaminants. The purpose of the study was to develop an analytical method for the sensitive determination of 69 analytes in bovine milk by liquid chromatography electrospray ionisation–tandem mass spectrometry. Material and Methods Antimicrobial, anabolic hormone, lactone, β-agonist, mycotoxin and pesticide residues were analysed in 120 raw milk samples from different dairy farms in North Macedonia. Stable isotopically labelled internal standards were used to facilitate effective quantification of the analytes. Results The linear regression coefficients were higher than 0.99, the limits of detection ranged from 0.0036 to 47.94 μg/L, and the limits of quantification ranged from 0.053 to 59.43 μg/L. The decision limit values ranged from 0.062 to 211.32 μg/L and the detection capability from 0.080 to 233.71 μg/L. Average recoveries of the analytes spiked in raw milk were in the range of 70.83% to 109%, intra-day coefficient of variation (CV) values from 2.41% to 22.29%, and inter-day CV values from 3.48% to 23.91%. The method was successfully applied in the testing of bovine milk samples. In five samples residues were detected. They were sulfadimethoxine (in two samples), enrofloxacin, tetracycline and oxytetracycline and were at concentrations below the EU maximum residue limit. Conclusion The method is useful for routine testing for this group of chemical hazards in bovine milk.

A different, reliable, and cost-effective strategy for the analysis of aflatoxins, ochratoxin A, and zearalenone in corn-based foods was proposed, including one multi-toxin immunoaffinity column (IAC) sample preparation and three different high-performance liquid chromatography fluorescence detection methods. The analytical procedures were tested and verified, keeping in mind their occurrence at trace levels in corn-based foods. With the validation of the proposed multi-toxin IAC methodology and comparison of the performance characteristics with methods using a single-toxin IAC, we confirmed the reliability of the multi-toxin IAC procedure versus the single-toxin IAC. The methods were validated by revealing satisfactory performance characteristics; for example, the obtained values of limit of detection were significantly lower than the maximum limits for all mycotoxins of concern. In addition, the recovery values were between 70.9 % and 106.1 % for all mycotoxins of interest, with precision values lower than 10.5 %.

Milk is one of the most important food products in the human diet and contains all the macronutrients, that are, proteins, carbohydrates, fat, vitamins (A, D and B groups) and trace elements, especially calcium, phosphorus, magnesium, zinc and selenium. Milk contamination is largely due to the grazing of animals on contaminated grass and drinking water. Grass is a direct source or route of radionuclides to animals and humans through the consumption of meat and milk. One of the important tasks of the veterinary activity is veterinary-sanitary supervision of the production and sale of milk and dairy products, whose main goal is the provision of biologically good milk and dairy products from healthy animals. The purpose of this study was to determine the activity concentrations of 226 Ra, 232 Th 40 K and 137 Cs in milk samples most commonly used in daily consumption in the Republic of North Macedonia and based on the results, the risk of radiation to the population can be estimated. An instrument -gamma spectrometer (Canberra Packard) with a high purity germanium detector and GENIE 2000 programme was used for measurement of the samples. On the basis of the performed tests, the main activity concentrations of 226 Ra, 232 Th, and 40 K were 1.76 ± 0.23; 1.05 ± 1.00; 31.9 ± 5.07 (Bq•kg -1 ), respectively. 40 K has the highest value compared to other radionuclides due to the process of transfer from soil to grass and from grass and water to milk. The activity of 137 Cs is below the detection limit for all tested milk types. This shows that there is no risk of radiation to the population, i.e., the safety limits are not exceeded, which points out the insignificant threat of radiation arising from radionuclides that are naturally or artificially present in the tested milk, and that reach humans through the food chain.