Carvacrol is an essential oil derived from oregano that is used as a natural additive to improve the efficiency of livestock nutrition. Residues of natural additives such as carvacrol should be monitored in food of animal origin to ensure consumer safety. The aim of this study was to appraise the quick, easy, cheap, effective, rugged and safe (QuEChERS) approach coupled with liquid chromatography and mass spectrometry as a means of carvacrol analysis in chicken tissue. A 5 ± 0.05 g portion of plasma, lung, muscle and liver was mixed for 15 min with 5 mL of 1-butanol and 20 mL of water, then centrifuged. A 0.5 mL volume from the top layer was transferred, then 60 mg of octadecylsilane sorbent, 30 mg of primary and secondary amine and 200 mg of MgSO₄ were added. The extract was mixed and centrifuged. The top layer was filtered and then transferred to an autosampler vial for analysis by high-performance liquid chromatography–tandem mass spectrometry. The limit of detection was calculated at 0.06 μg g⁻¹ and the limit of quantification was 0.2 μg g⁻¹, with relative standard deviation repeatability and reproducibility below <20%. The validation results showed that this method could be a good alternative to determination of carvacrol by gas chromatography and is suitable for carvacrol analysis in different matrices.

The major difficulty in analysis of nitrofurans in feed, feed water, and food of animal origin is that nitrofurans have low molecular weights and fast metabolism. The principal goal of this study was to prepare a procedure for the determination of nitrofurans and their metabolites by a single method in different types of feed, feed water, and food of animal origin. Two-gram samples were subjected to hydrolysis and derivatisation processes by addition of hydrochloric acid and 2-nitrobenzaldehyde. After incubation the sample was purified by solid phase extraction technique. Nitrofurans were analysed using ultra-high-pressure liquid chromatography-MS/MS (UHPLC-MS/MS). The results of validation fulfil the requirement of the confirmatory criteria according to the European Commission Decision 2002/657/EC regarding apparent recoveries (88.9%–107.3%), repeatability (2.9%–9.4%) and within-laboratory reproducibility (4.4%–10.7%). The method can be successfully applied to monitor nitrofurans and their metabolites in different matrices.

Introduction: The main problem in determination of chloramphenicol in food of animal origin is a large number of matrices. The main target of this study was to create a method for determination and confirmation of chloramphenicol in products and food of animal origin. Material and Methods: Each 5 g matrix sample was mixed with 5 mL of water and 10 mL of acetonitrile/ethyl acetate, homogenised, and centrifuged. The organic layer was evaporated and redissolved in 6 mL of 4% NaCl. The extract was cleaned up by SPE technique. Chloramphenicol was analysed by LC-MS/MS in electrospray mode. Results: The procedure was validated according to the Commission Decision No. 2002/657/EC. The apparent recoveries were in the range of 92.1% to 107.1% with a repeatability less than 11.0% (4.4%-11.0%) and within-laboratory reproducibility below 13.6% (4.7%-13.6%). Conclusion: The method was successfully validated and proved to be efficient, precise, and useful for quantification of chloramphenicol in more than 20 different matrices.

The organic food sector and consumer interest in organic products are growing continuously. The safety and quality of such products must be at least equal to those of conventional equivalents, but attaining the same standards requires overcoming a particular problem identified in organic food production systems: the occurrence of bacterial pathogens such as Salmonella, Campylobacter, Listeria monocytogenes, Staphylococcus aureus and pathogenic Escherichia coli. These food-borne microorganisms were detected in the production environments of such food. The prevalence of pathogenic bacteria in organic livestock and products may be higher, but may also be the same as or lower than in like material from conventional farms. Furthermore, the incidence of antimicrobial-resistant bacteria was more often detected in conventional than in organic production. The aim of this review was to present the recent information on the microbiological safety of food of animal origin produced from raw materials from organic farms.

Introduction: The main problem in poultry farming is the difficulty in producing food of animal origin without using antibacterial agents. Because most antibacterial compounds are dispensed in water, some water supply systems can be contaminated by antibiotics which are then administered to the animals unintentionally. This can lead to unexpected increases in antibiotic residues in food of animal origin. The aim of the present study was to determine whether the constant exposure of chicken broilers to enrofloxacin affects the withdrawal time of a therapeutic doxycycline that is intentionally administered to the chickens.Material and Methods: The concentrations of doxycycline, enrofloxacin, and ciprofloxacin were determined by LC-MS/MS in muscles and liver of the chickens.Results: Doxycycline residue concentrations in the chicken tissues from the group that received trace amounts of enrofloxacin were nearly 50% greater than those of the group that received only doxycycline.Conclusion: These results indicated that constant exposure to enrofloxacin in trace amounts significantly influences the residual doxycycline concentration in chicken tissues.

The transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) from a contaminated environment into the food chain is a serious consumer safety problem. As part of the Polish National Surveillance Program of PCDD/Fs and PCBs in food of animal origin, a concentration of PCDD/Fs of 4.61 ± 0.75 pg WHO-TEQ/g fat was determined in a sample of free-range eggs, which exceeded the permitted limit of 2.5 pg WHO-TEQ/g. The aim of the study was to investigate the source of the egg contamination and the risk for the eggs’ consumers. Eggs, muscles, feed and soil from the place where backyard waste burning had been carried out in the past and ash from a household stove tipped onto the paddock were analysed using the isotope dilution technique with high-resolution gas chromatography coupled with high-resolution mass spectrometry. The concentration in ash was low at 0.20 pg WHO-TEQ/g and the congener profile did not indicate the source of contamination. The dioxin content in soil from the backyard waste-burning site was 2.53 pg WHO-TEQ/g dry matter (d.m.) and the soil’s profile of PCDD/F congeners matched the profile of the contaminated eggs. By reason of the congener profile similarity, the investigation concluded, that the cause of the contamination was the backyard waste-burning site soil which the animals had access to. Frequent consumption of contaminated eggs from the analysed farm could pose a health risk due to chronic exposure, especially for vulnerable consumers.