Bioaccessibility of Polycyclic Aromatic Hydrocarbons (PAHs) in Grilled Meat: The Effects of Meat Doneness and Fat Content

Exposure to polycyclic aromatic hydrocarbons (PAHs) through diet is gaining concern due to the risk it poses to human health. This study evaluated the bioaccessibility of PAHs contained in charcoal-grilled beef and chicken in different segments of the gastrointestinal tract (GIT) with regard to the degree of doneness and fat content of the meats. The levels of 15 PAHs in the grilled meat samples and bioaccessible fractions were determined using high-performance liquid chromatography (HPLC) equipped with PAH column, and UV and fluorescence detectors. Total PAHs were found in beef (30.73 ng/g) and chicken (70.93 ng/g) before its digestion, and different PAHs’ bioaccessibility were observed in the different segments of GIT, with the highest in the stomach followed by the small intestine, despite the relatively higher bioaccessibility of individual PAHs in grilled beef as compared to those in grilled chicken. Additionally, the PAHs’ bioaccessibility increased with the increase in the degree of doneness. Positive linear correlation was observed for the PAHs’ bioaccessibility and the fat contents of grilled meat. Overall, this study highlights the influence of meat doneness (cooking time) and fat contents on the bioaccessibility and bioaccumulation of PAHs.

Morphological, Biochemical and Genotypic Analysis of Zoonotic Campylobacter jejuni Isolated from Chicken Meat Samples

Background: Campylobacter species are a leading cause of most important food-borne diarrhoeal illness worldwide while, poultry has been identified as a significant cause of Campylobacter infection in humans. C. jejuni is highly effective in colonizing chicken intestinal mucosa without causing any clinical manifestations and the consumption of poultry meat is the major source of transmission of bacteria to humans. Methods: The total of 19 chicken meat samples collected from retail markets in Chennai were screened by cultural examination, further subjected to phenotypic characterization using biochemical test and genotypic characterization using polymerase chain reaction assay targeting hip O and map A genes. Result: All the isolates showed growth on modified blood free charcoal cefoperazone deoxycholate agar media (mCCDA) and 18 (94.73%) samples showed typical morphological characteristics. The 12 (63.15%) isolates showed biochemical reactions positive. The results from polymerase chain reaction showed that 10 (83.33%) isolates were positive for C. jejuni. This study suggested that, it is essential to investigate the incidence of Campylobacter jejuni infection in poultry and the risk factors at all production stages of meat production to help reducing the disease in humans in terms of food safety.

Effect of the Addition of Thyme “Thymus vulgaris” Leaves on the Sensory and Nutritional Quality of Lamb Meat

Background: The shelf life of meat products can be increased by adding synthetic antioxidants. These antioxidants have long been used, but their safety has recently come into dispute due to a suspected carcinogenic potential. This is why meat technologies have extracted new natural antioxidants from spices and herbs, which are the best alternatives to synthetic compounds. So, the addition of natural flavors (essential oils, powder or extract of aromatic plants) to the meat can improve organoleptic quality and consumer acceptability. Methods: This study was conducted to evaluate the physicochemical and organoleptic qualities of meat fortified with thyme powder. With this purpose, 16 samples from four muscles of legs from 4 lambs were used in this work. The muscles were divided into two groups, control group (meat without any supplementation) and thyme group (meat supplemented with thyme). In this later group, a dose of 5% of ground thyme dry leaves was added to the meat. Result: Results showed no significant differences were found among groups for cooking loss, but was slightly higher for meat treated with thymus (33.29 vs. 28.36%). No significant differences between the two groups were observed for the ash, fat and crude protein contents of the meat. At the same manner, no effect was observed on meat lightness (L) and yellowness (b*) (P greater than 0.05), on the contrary, redness (a*) of the meat was affected by addition of thyme (11.28±1.23 vs. 23.06±9.80). Also, significant (P less than 0.05) differences were observed in texture scores, flavor, color and taste between control and the 5% thyme-supplemented meat samples. The overall acceptability of supplemented meat samples was highest (P≤0.05) as compared to control (5.91±2.32 vs. 4.35±2.66). In conclusion, addition of thyme leaves did not affect the physical and chemical properties of meat, except for redness and improved sensory quality.

Elixirs of Life, threats to Human and Environmental Well-being: Assessment of Antibiotic Residues in Raw Meat Sold Within Central Market Kaduna Metropolis, Kaduna State, Nigeria

Antibiotics, which are commonly used to treat human illnesses, are also used in animals for therapy, prophylaxis, and growth promotion. Sub-therapeutic antibiotic doses have typically been utilized for the last-mentioned purpose, which has contributed to resistance development. According to scientific data, certain antibiotic applications in food-producing animals can result in antibiotic resistance in intestinal bacteria, which can then be passed to the general population, causing treatment-resistant sickness. These antibiotic applications can also result in antibiotic resistance in non-pathogenic bacteria, whose resistance genes can be passed to disease-causing bacteria, resulting in antibiotic-resistant illnesses in people. Thus, this study assessed the antibiotics residues in raw meat sold in 6 slaughter houses in Kaduna State. The study is a descriptive cross-sectional study involving 6 slaughter houses in Central market Kaduna. Muscle, Kidney and liver samples were collected from each slaughterhouse. The antibiotic residues in the meat samples were analyzed using high performance liquid chromatography (HPLC) for tetracycline, ciprofloxacin and oxytetracycline residue results were presented in charts and tables. 18 different samples of beef (6 Muscles, 6 Liver and 6 Kidney) collected from abattoirs and meat vendors, the results shown that all beefs use three or more antimicrobial drugs. This research result revealed that 4(67%) tetracycline (oxytetracycline)were detected in meat samples at higher concentration), Oxytetraxycline (352.88, 221.58) of muscles is higher than (332.2, 217.05 of Liver and (263.33, 153.98) of Kidney is lower to muscles and liver. The Concentration of oxytetracycline were highest in muscles in samples 2. 3 and 6 which is above the WHO maximum residual limit. The concentration of streptomycin in the muscle, liver and kidney were detected (182.78, 56.23), (169.2, 58.39), (155.1, 50.20) but were within WHO Maximum residual limit. These high level of oxytetracycline residues in greater proportion of muscle samples destined for human consumption beyond MRLs could be as a result of the abuse of veterinary drugs as commonly practiced among livestock producers and vendors without observing withdrawal period prior to slaughter. The high-contamination rate of beef meat in the study areas is likely that consumers experience a high risk of exposure to drug residues.

Virulence Gene Profile, Antimicrobial Resistance and Multilocus Sequence Typing of Salmonella enterica Subsp. enterica Serovar Enteritidis from Chickens and Chicken Products

This study was undertaken to determine the virulence, antimicrobial resistance and molecular subtypes of Salmonella in the Central Region of Peninsular Malaysia. A total of 45 Salmonella Enteritidis were detected from live chicken (cloacal swab), and chicken products (fresh and ready-to-eat meat) samples upon cultural isolation and serotyping. Similarly, an antimicrobial susceptibility test based on the Kirby Bauer disk diffusion method as well as antimicrobial resistance AMR genes, virulence determinants and multilocus sequence typing (MLST) typing were conducted after the Whole Genome Sequencing and analysis of the isolates. The results indicate that sequence types ST1925 (63.7%), and ST11 (26.5%) were the predominant out of the seven sequence types identified (ST292, ST329, ST365, ST423 and ST2132). The phenotypic antimicrobial profile corresponds to the genotypic characterization in that the majority of the isolates that exhibited tetracycline, gentamycin and aminoglycoside resistance; they also possessed the tetC and blaTEM β-Lactam resistance genes. However, isolates from cloacal swabs showed the highest number of resistance genes compared to the chicken products (fresh and ready-to-eat meat) samples. Furthermore, most of the virulence genes were found to cluster in the Salmonella pathogenicity island (SPI). In this study, all the isolates were found to possess SPI-1, which codes for the type III secretion system, which functions as actin-binding proteins (SptP and SopE). The virulence plasmid (VP) genes (spvB, spvC) were present in all genotypes except ST365. The findings of this study, particularly with regard to the molecular subtypes and AMR profiles of the Salmonella Enteritidis serotype shows multidrug-resistance features as well as genetic characteristics indicative of high pathogenicity.

The Feasibility of Two Handheld Spectrometers for Meat Speciation Combined with Chemometric Methods and Its Application for Halal Certification

Handheld visible-near-infrared (Vis-NIR) and near-infrared (NIR) spectroscopy can be cost-effective, rapid, non-destructive and transportable techniques for identifying meat species and may be valuable for enforcement authorities, retail and consumers. In this study, a handheld Vis-NIR (400–1000 nm) and a handheld NIR (900–1700 nm) spectrometer were applied to discriminate halal meat species from pork (halal certification), as well as speciation of intact and ground lamb, beef, chicken and pork (160 meat samples). Several types of class modeling multivariate approaches were applied. The presented one-class classification (OCC) approach, especially with the Vis-NIR sensor (95–100% correct classification rate), was found to be suitable for the application of halal from non-halal meat-species discrimination. In a discriminant approach, using the Vis-NIR data and support vector machine (SVM) classification, the four meat species tested could be classified with accuracies of 93.4% and 94.7% for ground and intact meat, respectively, while with partial least-squares discriminant analysis (PLS-DA), classification accuracies were 87.4% (ground) and 88.6% (intact). Using the NIR sensor, total accuracies of the SVM models were 88.2% and 81.5% for ground and intact meats, respectively, and PLS-DA classification accuracies were 88.3% (ground) and 80% (intact). We conclude that the Vis-NIR sensor was most successful in the halal certification (OCC approaches) and speciation (discriminant approaches) for both intact and ground meat using SVM.

The Prevalence of Shiga Toxin-Producing Escherichia coli and Enteropathogenic Escherichia coli Isolated from Raw Chicken Meat Samples

Background. Shiga toxin-producing Escherichia coli (STEC) is known as a crucial zoonotic food-borne pathogen. A total of 257 raw chicken meat samples were collected from different markets in Hamadan, west of Iran, from January 2016 to May 2017. Materials and Methods. The samples were cultured in selective and differential culture media, and the virulence genes of E. coli isolates were analyzed by PCR assay. The antibiotic resistance patterns of E. coli isolates were determined by the disk diffusion method. The genetic relatedness of the E. coli O157 isolates was analyzed by ERIC-PCR. Results. In total, 93 (36% ± 3.12) of the isolates were identified as E. coli in this study. Based on serological and microbiological tests, 36 (38.7% ± 9.9), 7 (7.5% ± 5.35), and 12 (12.9% ± 6.81) of the E. coli isolates were characterized as STEC, enteropathogenic E. coli (EPEC), and attaching and effacing E. coli (AEEC) strains, respectively. A high level of resistance to nalidixic acid (91.4% ± 5.7), tetracycline (89.2% ± 6.31), ampicillin (82.8% ± 7.67), and trimotoprime-sulfametoxazole (71% ± 9.22) was detected among the E. coli isolates. The analysis of the ERIC-PCR results showed five different ERIC types among the E. coli O157 isolates. Conclusions. Based on our findings, control and check-up of poultry meats should be considered as a crucial issue for public health.

A Water-Dispersible Carboxylated Carbon Nitride Nanoparticles-Based Electrochemical Platform for Direct Reporting of Hydroxyl Radical in Meat

In this paper, carboxylated carbon nitride nanoparticles (carboxylated-g-C3N4 NPs) were prepared through a one-step molten salts method. The synthesized material was characterized by transmission electron microscope (TEM), Fourier transform-infrared spectra (FTIR), and X-ray photoelectron spectroscopy (XPS), etc. An electrochemical sensor based on single-stranded oligonucleotide/carboxylated-g-C3N4/chitosan/glassy carbon electrode (ssDNA/carboxylated-g-C3N4/chitosan/GCE) was constructed for determination of the hydroxyl radical (•OH), and methylene blue (MB) was used as a signal molecule. The sensor showed a suitable electrochemical response toward •OH from 4.06 to 122.79 fM with a detection limit of 1.35 fM. The selectivity, reproducibility, and stability were also presented. Application of the sensor to real meat samples (i.e., pork, chicken, shrimp, and sausage) was performed, and the results indicated the proposed method could be used to detect •OH in practical samples. The proposed sensor holds a great promise to be applied in the fields of food safety.