Food Safety Concerns of Pesticides, Veterinary Drug Residues and Mycotoxins in Meat and Meat Products

Determination of residues of pesticides, anabolic steroids, antibiotics, and antibacterial compounds in meat products in Oman by liquid chromatography/mass spectrometry and enzyme-linked immunosorbent assay

BACKGROUND AND AIM

Meat is a rich source of many nutrients and plays a vital role in human life however, meat safety is one of the top priorities of great concern for consumers today. More than 90% of human exposure to harmful materials is due to consumption of contaminated meat products. This study was designed to compare four valid analytical methods for the determination of organochlorine pesticides 2,4 D (2,4-dichlorophenoxyacetic acid), dichlorodiphenyldichloroethylene/dichlorodiphenyltrichloroethane, alachlor, organophosphate, anabolic steroids (progesterone, testosterone, and estrogen), antibiotics (tetracycline, sulfonamides, gentamycin, and cephalexin), antibacterial compounds (Macrolide, ß-Lactam, Chloramphenicol, Sulphur drugs, and Gentamicin) residues in 135 beef, buffalo, and sheep meat samples (fresh, frozen meats, minced, and sausage samples) of local, regional, and international brands available in Omani markets.

MATERIALS AND METHODS

Triplicate meat samples from each brand within each species were extracted with acetonitrile and purified with acetonitrile-saturated n-hexane to remove all impurities. To dry the sample after heating, the residue was passed across a Sep-Pak C18 cartridge for sample cleaning before gas chromatography (GC) (Brand GCMS-QP2010 Plus) coupled with different detectors, including a mass spectrometer or GC-electron capture detector (GC-ECD). Liquid chromatography/mass spectrometry (LC-MS) was also employed for the quantification of the residues in meat products. Enzyme-linked immunosorbent assay (ELISA) kits were employed to assess veterinary drug residues, anabolic steroids, and pesticides. The CHARM II instrument was employed to detect chloramphenicol, gentamicin, sulfa-drug, ß-lactam, and macrolide residues in meat and meat product samples.

RESULTS

A thin-layer chromatographic (TLC) method should be considered as another method of choice to determine concentrations of veterinary drugs and anabolic steroids. The TLC results were validated by LC-MS. The three described methods permit the multi-residue analysis of anabolic steroid residue levels of 0.06-1.89 ppb in meat product samples. There were three violative residues of anabolic steroids in red meat products that were above the maximum residue limits (MRLs). Although, the levels of organochlorine pesticides and antibiotic concentrations in meat products were below the MRLs, the long-term consumption is considered a health hazard and will affect the wellbeing of consumers.

CONCLUSION

The four techniques (GC, high-performance liquid chromatography, ELISA and CHARM II) provided results that were reliable and precise for the detection of chessssmical residues in meat and meat products.

A highly sensitive immunoassay of pesticide and veterinary drug residues in food by tandem conjugation of bi-functional mesoporous silica nanospheres

A novel type of enzyme-antibody conjugation using mesoporous silicon nanospheres (MSN) was developed, which amplified the labeling signal and highly increased the sensitivity of enzyme-linked immunosorbent assay (ELISA) for the determination of pesticide and veterinary drug residues in food. First, conjugates were prepared through layer-by-layer immobilization of an enzyme and an antibody on an MSN scaffold. Then the MSN scaffold was employed for labeling and signal amplification to develop a sensitive colorimetric immunoassay through the catalytic oxidation reaction of 5,50-tetramethylbenzidine (TMB). When this MSN-based ELISA was applied to detect chloramphenicol, avermectin, tetracycline and streptomycin in food samples, it provided linear ranges of 0.025 ng ml-1-25 ng ml-1, 0.05 ng ml-1-10 ng ml-1, 0.025 ng ml-1-10 ng ml-1 and 0.05 ng ml-1-25 ng ml-1, respectively, with low detection limits down to 0.011 ng mL-1, 0.134 ng mL-1, 0.015 ng ml-1 and 0.106 ng ml-1, respectively. For avermectin, it provided a 16.7-fold decrease of the limit of detection in contrast to that of standard ELISA without the loss of method specificity and accuracy. This novel immunoassay was hypersensitive, simple and easy-to-use, which made it high potential in applying for the accurate analysis of harmful substances in food.

Determination of gentamicin use in poultry farms in Enugu state, Nigeria, and detection of its residue in slaughter commercial broilers

Background and Aim: Gentamicin is a broad-spectrum antimicrobial used in the treatment of a variety of bacterial infections in poultry, its residue in tissues is known to have a deleterious effect in man when consumed. The study aimed to determine the use of gentamicin by poultry farmers and the presence and occurrence of gentamicin residue in tissues of commercial broilers in Ikpa slaughterhouse Nsukka. Materials and Methods: The study adopted a cross-sectional survey using questionnaire and immunological screening. A total of 108 broilers were sampled, testing 108 each of muscle, liver, and kidney tissues for gentamicin residue using enzyme-linked immunosorbent assay. Results: The questionnaire survey revealed that in the management practices, 55.2% of the farms used intensive deep litter, 21% intensive battery cage, and 23.6% extensive farming system. Twenty-seven (71%) farms reared only broilers, 10.5% layers, and 18.4% both. The feeding management showed that 21.1% of farmers produced their own feed (medicated) while 78.8% used commercial feed, of which 11.5% incorporated antibiotics. Hundred (100%) of the respondents used gentamicin and only 47.3% were aware of the consequences of antimicrobial residue in foods of animal origin, with knowledge of the legislation on the prudent use of antimicrobials in food animals. The occurrence of gentamicin residue in surveyed birds was 65% with tissue distribution as follows: Muscle (44.4%), liver (51.9%), and kidney (59.3%). Conclusion: Poultry farms in the study area make constant use of gentamicin without observing its withdrawal period before sale, and a high percentage of the commercial birds meant for human consumption contains gentamicin residue. Therefore, consumers might be at risk of consuming gentamicin as a parent drug or its metabolites in commercial poultry.

Determining anthelmintic residues in goat milk in Brazil

SUMMARY Anthelmintics are used to combat nematodes. The misuse of anthelmintics can raise the cost of milk production. The objective of this research was to determine the presence of anthelmintics in goat milk. Twenty goats were used, divided into four groups of five animals: I- animals treated with an ivermectin-based anthelmintic; II- animals treated with moxidectin; III- animals treated with levamisole hydrochloride; and IV: animals treated with albendazole. Milk samples were collected individually: before, and 1, 2, 3, 15 and 21 days after administration of the anthelmintics. Determination of anthelmintic residues was performed by liquid chromatography-mass spectrometry (LC-MS). According to the results, there was an exponential effect (P<0.05) for ivermectin and moxidectin. Moxidectin was the anthelmintic that left a residue in the milk for the longest time, up to 21 days. However, with all the anthelmintics researched, residues were below the maximum limit recommended by the inspecting agencies.