Animal-derived Foods Research Articles

Multiclass method for detecting 41 antibiotic residues in bovine liver, muscle, and milk using LC-Q-Orbitrap-HRMS

This study developed and validated an analytical method for the simultaneous identification and quantification of 41 veterinary antibiotic drugs from 9 different classes, including sulfonamides, quinolones, tetracyclines, penicillins, macrolides, nitroimidazoles, cephalosporins, diaminopyrimidines, and amphenicol, in animal-derived food products. The method used modified QuEChERS and liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap HRMS). The method was validated in accordance with Commission Implementing Regulation (CIR) EU 2021/808 at five different concentrations ranging from 0.075 to 10,000 μg kg−1. The mean recoveries ranged from 58 % to 123 %, while repeatability values were all below 21 %. The calibration curves showed good linearity, with correlation coefficients (R2) ranging from 0.9905 to 0.9999. The limits of detection (LOD) and limits of quantification (LOQ) were in the range of 0.005–43.0 μg kg−1 and 0.008–71.7 μg kg−1, respectively. The decision limit (CCα) and detection capability (CCβ) ranges were 0.37–2347 µg/kg and 0.44–3099 µg/kg, respectively. Out of the 1330 samples collected from Egyptian local markets, 1.20 % had antibiotic residues. The applicability of the developed method was proven through successful four proficiency testing (PT). The proposed method was demonstrated to be reliable for the simultaneous analysis of multiclass veterinary drugs in bovine liver, muscle tissue, and milk.

An exonuclease I-assisted quencher-free 2-aminopurine aptasensor based on a multipath paper-based device for ultrasensitive detection of kanamycin

A quencher-free multipath microfluidic paper-based analytical device (µPAD) was constructed for ultrasensitive detection of kanamycin based on exonuclease I (Exo I)-assisted signal enhancement of 2-aminopurine (2-AP). Here, Exo I, a single-stranded DNA-specific nuclease, was introduced to fully liberate 2-AP mononucleotides to greatly enhance biosensing sensitivity. 2-AP, a fluorescent adenine analogue embedded in single-stranded DNA (ssDNA), was employed as the detection signal source. The fluorescence of 2-AP is strong in the mononucleotide state, while it can have low fluorescence and even no fluorescence in ssDNA and dsDNA, respectively. The 2-AP fluorescence probe included 2-AP DNA and kanamycin aptamer. When kanamycin was present, binding occurred between kanamycin and the aptamer, leading to ssDNA, which was further digested by Exo I. In this case, free 2-AP mononucleotides were liberated, indicating strong fluorescence. In addition, the captured kanamycin was released for binding with the new aptamer, which resulted in the formation of a binding-hydrolysis-release cycle with the aid of Exo I. Under optimal conditions, this µPAD exhibited sensitive and multipath detection of kanamycin at concentrations as low as 1.26 × 10−14 M with a wide range of 10−13–10−7 M. Furthermore, satisfactory results were achieved for analysing spiked kanamycin in milk and honey samples. This strategy is a very promising tool for monitoring antibiotics and evaluating the safety of animal-derived foods.

Biofortification of Plant- and Animal-Based Foods in Limiting the Problem of Microelement Deficiencies-A Narrative Review.

With a burgeoning global population, meeting the demand for increased food production presents challenges, particularly concerning mineral deficiencies in diets. Micronutrient shortages like iron, iodine, zinc, selenium, and magnesium carry severe health implications, especially in developing nations. Biofortification of plants and plant products emerges as a promising remedy to enhance micronutrient levels in food. Utilizing agronomic biofortification, conventional plant breeding, and genetic engineering yields raw materials with heightened micronutrient contents and improved bioavailability. A similar strategy extends to animal-derived foods by fortifying eggs, meat, and dairy products with micronutrients. Employing "dual" biofortification, utilizing previously enriched plant materials as a micronutrient source for livestock, proves an innovative solution. Amid biofortification research, conducting in vitro and in vivo experiments is essential to assess the bioactivity of micronutrients from enriched materials, emphasizing digestibility, bioavailability, and safety. Mineral deficiencies in human diets present a significant health challenge. Biofortification of plants and animal products emerges as a promising approach to alleviate micronutrient deficiencies, necessitating further research into the utilization of biofortified raw materials in the human diet, with a focus on bioavailability, digestibility, and safety.

Meta-analysis on the global prevalence of Arcobacter in food-producing animals and humans

The genus Arcobacter has been associated with illnesses in both animals and humans, where Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii have been linked to numerous cases of gastrointestinal diseases in humans. While isolated instances of Arcobacter infection have been reported in certain areas, comprehensive data reflecting the global impact of Arcobacter infection are lacking. This meta-analysis was conducted with the objective of assessing the aggregated prevalence of Arcobacter across diverse sources on a global scale. We conducted a thorough literature search of the Scopus, PubMed, and ScienceDirect databases to identify studies published from 1992 to 2022 on Arcobacter prevalence in humans and food-producing animals. We utilized multilevel random effects meta-analysis models to gauge the average occurrence of Arcobacter and to examine various factors that could influence incidence outcomes. Seventy-five articles were included in the meta-analysis. The pooled prevalence of Arcobacter spp. from different sources was 21.9% (95% CI: 18.0%–26.1%), and the mean prevalence of A. butzleri, A. cryaerophilus, and A. skirrowii was 15.1%, 2.8%, and 0.1%, respectively. Arcobacter spp. had the lowest prevalence in humans (1.8%; 95% CI: 0.7%–3.3%) and the highest in broilers (38.8%; 95% CI: 28.0%–50.1%). Among animal-derived food products, carcasses or carcass parts exhibited the highest Arcobacter spp. prevalence of 28.6% (28.6%; 95% CI: 23.7%–33.7%). This meta-analysis revealed that A. butzleri is the most prevalent Arcobacter species worldwide, with broilers, as well as seafood, being the primary hosts of Arcobacter spp. We recommend developing appropriate prevention strategies and conducting further local in-depth studies to establish the actual epidemiological burden of Arcobacter.

THE USE OF ANTIBIOTICS IN FOOD ANIMALS – A THREAT TO HUMAN HEALTH

Background: Antibiotics are widely used in food animals to prevent disease, promote growth and maintain productivity. Modern animal production practices involve regular use of antimicrobials, but abusive use can lead to harmful consequences. The aim of this review was to provide comprehensive information regarding the risk of regular application of antibiotics in food animals, the potential consequences and impact on human health, and options for the prevention of antibiotic resistance in the food chain. Review Results: Although organizations such as WHO, UN, and EU have taken steps to reduce and limit the use of antibiotics in animals, these are proving insufficient in developing countries. In many countries, the antibiotics used in animals appear to exceed that in humans. The abuse in food animals promotes the development of antibiotic-resistant bacteria and resistance genes that can be transmitted to humans through food consumption and direct contact with animal food or environment mechanisms. This can lead to human infections with antibiotic-resistant bacteria, causing treatment failure and, therefore, more severe and longer-lasting illnesses, increased hospitalization rates, more deaths and higher costs to society. Furthermore, as food animals and animal-derived foods are traded globally, they contribute to antibiotic resistance in countries far from where the problem originates. Conclusion: Overcoming the problem of antibiotic resistance requires a multidisciplinary approach with effective action coordination and information exchange between the agricultural, food, veterinary and health sectors. Through international cooperation, efforts should focus on reducing unnecessary antibiotics use and reducing the spread of antibiotic-resistant bacteria, but national-level action on antibiotic resistance and food safety is also essential.

Epidemiological and genetic characterization of multidrug-resistant non-O1 and non-O139 Vibrio cholerae from food in southern China

This study reports a comprehensive epidemiological and genetic analysis of V. cholerae strains, specifically non-O1/non-O139 serogroups, isolated from animal-derived food samples in Guangdong province from 2015 to 2019. A total of 21 V. cholerae strains were obtained, which exhibited high resistance rates for nalidixic acid (57.14 %, 12/21), ampicillin (33.33 %, 7/21), and ciprofloxacin (19.05 %, 4/21). The quinolone resistance-related gene, qnrVC, was prevalent in 80.95 % (17/21) of the isolates. Additionally, chromosomally mediated quinolone-resistance mutations, including mutations in GyrA at position 83 (S83I) and ParC at position 85 (S85L), were detected in 47.62 % of the isolates. The combination of target mutation and qnrVC genes was shown to mediate resistance or intermediate resistance to ciprofloxacin in V. cholerae. Furthermore, an IncC-type conjugative plasmid carrying thirteen antibiotic resistance genes, including genes conferring resistance to two clinically important antibiotics, cephalosporins and fluoroquinolones, was identified in the shrimp-derived strain Vc516. While none of our food isolates harbored the toxigenic CTX- and TCP-encoding genes, they did possess genes encoding toxins such as HlyA and Autoinducer-2. Notably, some V. cholerae strains from this study exhibited a close genetic relationship with clinical strains, suggesting their potential to cause human infections. Taken together, this study provides a comprehensive view of the epidemiological features and genetic basis of antimicrobial resistance and virulence potential of V. cholerae strains isolated from food in southern China, thereby advancing our understanding of this important pathogen.

Ultrasensitive Ti3C2Tx@Pt-Based Immunochromatography with Catalytic Amplification and a Dual Signal for the Detection of Chloramphenicol in Animal-Derived Foods.

Herein, a catalytic amplification enhanced dual-signal immunochromatographic assay (ICA) based on Pt nanoparticles (Pt NPs) modified with Ti3C2Tx MXene (Ti3C2Tx@Pt) was first developed for chloramphenicol (CAP) in animal-derived foods. Due to the large specific surface area and abundant active sites of Ti3C2Tx@Pt, they can be loaded with hundreds of Pt NPs to enhance their catalytic activity, resulting in a significant increase in the detection sensitivity; the sensitivity was up to 50-fold more sensitive than the reported ICA for CAP. The LODs of the developed method for milk/chicken/fish were 0.01 μg/kg, the LOQs were 0.03 μg/kg and the recovery rates were 80.5-117.0%, 87.2-118.1% and 92.7-117.9%, with corresponding variations ranging from 3.1 to 9.6%, 6.0 to 12.7% and 6.0 to 13.6%, respectively. The linear range was 0.0125-1.0 μg/kg. The results of the LC-MS/MS confirmation test on 30 real samples had a good correlation with that of our established method (R2 > 0.98), indicating the practical reliability of the established method. The above results indicated that an ICA based on the Ti3C2Tx@Pt nanozyme has excellent potential as a food safety detection tool.

Identification of an Enterococcus faecium strain isolated from raw bovine milk co-harbouring the oxazolidinone resistance genes optrA and poxtA in China

Oxazolidinones are potent antimicrobial agents used to treat human infections caused by multidrug-resistant Gram-positive bacteria. The growing resistance to oxazolidinones poses a significant threat to public health. In August 2021, a linezolid-resistant Enterococcus faecium BN83 was isolated from a raw milk sample of cow in Inner Mongolia, China. This isolate exhibited a multidrug resistance phenotype and was resistant to most of drugs tested including linezolid and tedizolid. PCR detection showed that two mobile oxazolidinones resistance genes, optrA and poxtA, were present in this isolate. Whole genome sequencing analysis revealed that the genes optrA and poxtA were located on two different plasmids, designated as pBN83–1 and pBN83–2, belonging to RepA_N and Inc18 families respectively. Genetic context analysis suggested that optrA gene on plasmid pBN83–1 was located in transposon Tn6261 initially found in E. faecalis. Comprehensive analysis revealed that Tn6261 act as an important horizontal transmission vector for the spread of optrA in E. faecium. Additionally, poxtA-bearing pBN83–2 displayed high similarity to numerous plasmids from Enterococcus of different origin and pBN83–2-like plasmid represented a key mobile genetic element involved in movement of poxtA in enterococcal species. The presence of optrA- and poxtA-carrying E. faecium in raw bovine milk represents a public health concern and active surveillance is urgently warranted to investigate the prevalence of oxazolidinone resistance genes in animal-derived food products.

Animal-derived food allergen: A review on the available crystal structure and new insights into structural epitope.

Immunoglobulin E (IgE)-mediated food allergy is a rapidly growing public health problem. The interaction between allergens and IgE is at the core of the allergic response. One of the best ways to understand this interaction is through structural characterization. This review focuses on animal-derived food allergens, overviews allergen structures determined by X-ray crystallography, presents an update on IgE conformational epitopes, and explores the structural features of these epitopes. The structural determinants of allergenicity and cross-reactivity are also discussed. Animal-derived food allergens are classified into limited protein families according to structural features, with the calcium-binding protein and actin-binding protein families dominating. Progress in epitope characterization has provided useful information on the structural properties of the IgE recognition region. The data reveals that epitopes are located in relatively protruding areas with negative surface electrostatic potential. Ligand binding and disulfide bonds are two intrinsic characteristics that influence protein structure and impact allergenicity. Shared structures, local motifs, and shared epitopes are factors that lead to cross-reactivity. The structural properties of epitope regions and structural determinants of allergenicity and cross-reactivity may provide directions for the prevention, diagnosis, and treatment of food allergies. Experimentally determined structure, especially that of antigen-antibody complexes, remains limited, and the identification of epitopes continues to be a bottleneck in the study of animal-derived food allergens. A combination of traditional immunological techniques and emerging bioinformatics technology will revolutionize how protein interactions are characterized.

Highly electroactive Co–ZnO/GO nanocomposite: Electrochemical sensing platform for oxytetracycline determination

Antimicrobial residues in animal-derived foods have become a major source of concern around the world. Oxytetracycline (OTC), one of these antibiotics that belongs to the tetracycline family should be detected in these matrices. Nanostructured metal oxides have attracted a lot of scientific attention due to their special characteristics that can be exploited for creating innovative nanodevices. Therefore, in the present study, we report the fabrication of cobalt-doped ZnO/GO nanocomposites for OTC sensors using a simple and environmentally friendly method that does not require toxic solvents. Contact angle measurements, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–Vis were used to confirm the successful fabrication of the Co–ZnO/GO nanocomposite and to determine the surface area, Structural, morphological features, chemical composition and purity of the nanocomposite. The electrochemical and electrocatalytic properties were recorded using cyclic voltammetry (CV), electrochemical impedance spectroscopy, and differential pulse voltammetry (DPV). Optimizing parameters such as scan rate, pH value, deposition time, and deposition potential, we achieve a wide linear concentration range from 10−12 M to 10−7 M, with an impressive detection limit of 1.6 10−13 M.Notably, our sensor exhibits remarkable selectivity, demonstrating its usefulness for the detection of oxytetracycline traces in real milk samples. These results emphasize the novelty and practical significance of our work and provide a promising avenue for the development of sensitive and selective electrochemical sensing platforms in various fields.

Detection of selected antimicrobial residues in red meat and kidney of beef cattle slaughtered at Nekemte municipal abattoir, Ethiopia.

Antibiotics are commonly used drugs in farm animals for therapeutic, prophylactic and diagnosis purposes. As a result of the use of antibiotics in livestock, residues of antibiotics may be present in animal-derived foods, especially in meat. This study aimed at determining the antibiotic residues in cattle slaughtered at Nekemte municipal abattoir and assessing the knowledge, attitude and practice (KAP) level of the community about antibiotic residue in food of cattle origin. A cross-sectional study was conducted on randomly selected kidney and muscle samples slaughtered at Nekemte municipal abattoir. The samples were collected aseptically and analysed using liquid chromatography mass spectrometer. In addition the KAP of cattle handlers, butcher men and meat users were collected using structured questionnaire. The data was analysed by SPSS and intercooled Stata version 7.0, 2001. Results are presented as percentages and frequency distributions in tabular and graphical form. From 120 individuals interviewed, only 25.83% knew about withdrawal time and had limited knowledge on effect of antibiotic residue on human health, whereas about 47.5% did not heard about antibiotic residue in meat. Tetracycline was detected in all the sampled meat 60 (100%), whereas oxytetracycline residues were detected in half 15 (50%) of the samples. In the current study doxycycline, sulphadiazine, penicillin G and enrofloxacin were not detected in all samples. Oxytetracycline residue levels ranged from 0.00 to 463.35µg/kg for the kidney and 0.00 to 354.55µg/kg for muscle samples. About 10% of kidney and 3.33% muscle samples collected had oxytetracycline residues above maximum residue limits. In general, the study revealed that oxytetracycline residues were prevalent among antimicrobial residues analysed from the study area. The study indicated the presence of high antimicrobial residue and hence exposes for antimicrobial resistance of pathogens warranting coordinated effort to mitigate its health effect on the animal and hence human being.

Realization path and connotation of the Healthy China strategy: macroscopic perspective of dietary structure and the entry of individual health consciousness

BackgroundDietary rationality and health concept have certain influence on individual health level. This study aims to explore the characteristics and existing problems of Chinese residents’ health behaviors from both macro and micro perspectives, and explore the feasibility and realization path of Healthy China strategy.MethodsWe utilized regression models to evaluate the correlation between diet and the risk of disease causes of death. By use of the linear regression analysis model, we distinguished the impact of each dimension on health literacy index at the individual level. Then, we explored the influential factors of the diet health index using the binary logit regression model.ResultsIncreased consumption of animal-derived foods in China has contributed to the burden of non-communicable diseases. The individuals’ health awareness is still weak, and the health literacy index is greatly affected by the diet, while the individual gender and age are positively correlated with the diet health index, and the individual body mass index (BMI) level is negatively correlated with the diet health index.ConclusionsThis study provided a comprehensive understanding of existing problems of Chinese residents’ health behaviors. We have proposed a path model for the implementation of the Healthy China strategy from the perspectives of “diet health, physical health, conceptual health and environmental health,” which is also a great contribution to the world.

Exploring Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli in Food-Producing Animals and Animal-Derived Foods.

Antimicrobials serve as crucial treatments in both veterinary and human medicine, aiding in the control and prevention of infectious diseases. However, their misuse or overuse has led to the emergence of antimicrobial resistance, posing a significant threat to public health. This review focuses on extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in animals and their associated food products, which contribute to the proliferation of antimicrobial-resistant strains. Recent research has highlighted the presence of ESBL-producing E. coli in animals and animal-derived foods, with some studies indicating genetic similarities between these isolates and those found in human infections. This underscores the urgent need to address antimicrobial resistance as a pressing public health issue. More comprehensive studies are required to understand the evolving landscape of ESBLs and to develop strategic public health policies grounded in the One Health approach, aiming to control and mitigate their prevalence effectively.

The Bioaccessibility and Bioavailability of Pentachlorophenol in Five Animal-Derived Foods Measured by Simulated Gastrointestinal Digestion.

Pentachlorophenol (PCP) is a ubiquitous emerging persistent organic pollutant detected in the environment and foodstuffs. Despite the dietary intake of PCP being performed using surveillance data, the assessment does not consider the bioaccessibility and bioavailability of PCP. Pork, beef, pork liver, chicken and freshwater fish Ctenopharyngodon Idella-fortified by three levels of PCP were processed by RIVM and the Caco-2 cell model after steaming, boiling and pan-frying, and PCP in foods and digestive juices were detected using isotope dilution-UPLC-MS/MS. The culinary treatment and food matrix were significantly influenced (p < 0.05) in terms of the bioaccessibility and bioavailability of PCP. Pan-frying was a significant factor (p < 0.05) influencing the digestion and absorption of PCP in foods, with the following bioaccessibility: pork (81.37-90.36%), beef (72.09-83.63%), pork liver (69.11-78.07%), chicken (63.43-75.52%) and freshwater fish (60.27-72.14%). The bioavailability was as follows: pork (49.39-63.41%), beef (40.32-53.43%), pork liver (33.63-47.11%), chicken (30.63-40.83%) and freshwater fish (17.14-27.09%). Pork and beef with higher fat content were a key factor in facilitating the notable PCP bioaccessibility and bioavailability (p < 0.05). Further, the exposure of PCP to the population was significantly reduced by 42.70-98.46% after the consideration of bioaccessibility and bioavailability, with no potential health risk. It can improve the accuracy of risk assessment for PCP.

Fluorescence quenching biomimetic ELISA based on quantum dots for enrofloxacin detection in animal-derived foods

In this study, two novel fluorescence quenching biomimetic enzyme-linked immunosorbent assays were constructed for the sensitive detection of enrofloxacin (ENRO) in animal-derived foods. In this strategy, the fluorescence of quantum dots (QDs) was efficiently quenched by the enzymatic formation of horseradish peroxidase (HRP) and Prussian blue nanoparticles (PBNPs) in biomimetic enzyme-linked immunosorbent (BELISA). Under the optimal conditions, the detection limit (IC15) of the method using HRP was 1.67 ng/L, and the sensitivity (IC50) was 0.57 μg L−1, while IC15 of the method using PBNPs reached to 1.02 ng/L, and IC50 was 0.04 μg L−1. The recoveries of these proposed methods ranged from 83.37 to 118.08 %, with the CV values of 0.32–17.01 %. The results from the proposed methods showed high agreement with results yielded by using HPLC. In a conclusion, this conversion of the absorption signal into fluorescent signals led to an increase in the sensitivity of ENRO detection in animal-derived foods. And it is worth noting that compared to the proposed fluorescence quenching BELISA using HRP as catalyst, the method using PBNPs as catalyst showed a higher sensitivity with a 14-fold lower IC50, demonstrating the good application prospect of nano-enzyme in biomimetic immunoassay.

Halogenated aromatic pollutants in routine animal-derived food of south China: Occurrence, sources, and dietary intake risks

Halogenated aromatic pollutants (HAPs) including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) exhibit diverse toxicities and bio-accumulation in animals, thereby imposing risks on human via animal-derived food (ADF) consumption. Here we examined these HAPs in routine ADFs from South China and observed that PBDEs and PCBs showed statistically higher concentrations than PCDD/Fs and PBDD/Fs. PCDD/Fs and PCBs in these ADFs were mainly from the polluted feed and habitat of animals, except PCDD/Fs in egg, which additionally underwent selective biotransformation/progeny transfer after the maternal intake of PCDD/F-polluted stuff. PBDEs and PBDD/Fs were mostly derived from the extensive use of deca-BDE and their polluted environments. Significant interspecific differences were mainly observed for DL-PCBs and partly for PBDD/Fs and PBDEs, which might be caused by their distinct transferability/biodegradability in animals and the different living habit and habitat of animals. The dietary intake doses (DIDs) of these HAPs via ADF consumption were all highest for toddlers, then teenagers and adults. Milk, egg, and fish contributed most to the DIDs and risks for toddlers and teenagers, which results of several cities exceeded the recommended thresholds and illustrated noteworthy risks. Pork, fish, and egg were the top three risk contributors for adults, which carcinogenic and non-carcinogenic risks were both acceptable. Notably, PBDD/Fs showed the lowest concentrations but highest contributions to the total risks of these HAPs, thereby meriting continuous attention.

Fragmentation characteristics-based nontargeted screening method of exogenous chemical residues in animal-derived foods using reversed-phase and hydrophilic interaction liquid chromatography–high-resolution mass spectrometry

Fragmentation characteristics are crucial for nontargeted screening to discover and identify unknown exogenous chemical residues in animal-derived foods. In this study, first, fragmentation characteristics of 51 classes of exogenous chemical residues were summarized based on experimental mass spectra of standards in reversed-phase and hydrophilic interaction liquid chromatography–high-resolution mass spectrometry (MS) and mass spectra from the MassBank of North America (MoNA) library. According to the proportion of fragmentation characteristics to the total number of chemical residues in each class, four screening levels were defined to classify 51 classes of chemical residues. Then, a nontargeted screening method was developed based on the fragmentation characteristics. The evaluation results of 82 standards indicated that more than 90 % of the chemical residues with MS/MS spectra can be identified at concentrations of 100 and 500 μg/kg, and about 80 % can be identified at 10 μg/kg. Finally, the nontargeted screening method was applied to 16 meat samples and 21 egg samples as examples. As a result, eight chemical residues and transformation products (TPs) of 5 classes in the exemplary samples were found and identified, in which 3 TPs of azithromycin were identified by fragmentation characteristics-assisted structure interpretation. The results demonstrated the practicability of the nontargeted screening method for routine risk screening of food safety.

Ratiometric fluorescence platform for the ultrasensitive detection of kanamycin based on split aptamer co-recognition triggers Mg2+-DNAzyme-driven DNA walker systems

In this work, a novel 3D-DNA walker signal amplification strategy was designed to construct a fluorescent aptasensor for the detection of kanamycin (KAN). The aptasensor utilizes split aptamers for the synergistic recognition of KAN. The presence of KAN induces the split aptamers recombination to form the Mg2+-DNAzyme structure, which is activated by Mg2+ to drive the 3D-DNA walker process for cascading signal amplification. Employing gold nanoflowers (AuNFs) as walking substrate material increases the local DNA concentration to enhance the walker efficiency. The prepared fluorescent aptasensor achieved efficient and sensitive detection of KAN with satisfactory results in the concentration range of 1 × 10−8 - 1 × 10−3 μg/kg and the detection limit of 5.63 fg/kg. Meanwhile, the designed fluorescent aptasensor exhibited favorable specificity, anti-interference, storage stability and reproducibility, and verified the feasibility of its application in milk samples. The present work provides an effective tool for the regulation of KAN contamination in animal-derived foods with promising prospects.

New evidence for gut-muscle axis: Lactic acid bacteria-induced gut microbiota regulates duck meat flavor

The interaction between gut microbiota and muscles through the gut-muscle axis has received increasing attention. This study attempted to address existing research gaps by investigating the effects of gut microbiota on meat flavor. Specifically, lactic acid bacteria were administered to ducks, and the results of e-nose and e-tongue showed significantly enhanced meat flavor in the treatment group. Further analyses using GC–MS revealed an increase in 6 characteristic volatile flavor compounds, including pentanal, hexanal, heptanal, 1-octen-3-ol, 2,3-octanedione, and 2-pentylfuran. Linoleic acid was identified as the key fatty acid that influences meat flavor. Metagenomic and transcriptomic results further confirmed that cecal microbiota affects the duck meat flavor by regulating the metabolic pathways of fatty acids and amino acids, especially ACACB was related to fatty acid biosynthesis and ACAT2, ALDH1A1 with fatty acid degradation. This study sheds light on a novel approach to improving the flavor of animal-derived food.

Highly sensitive molecularly imprinted sensor modified with BC/AuNPs@ZIF-8 for the detection of norfloxacin in animal-derived foods

In this work, we constructed a molecularly imprinted sensor for the specific detection of trace norfloxacin in animal-derived foods, using activated biochar (BC) and gold nanoparticle-modified zeolite imidazolium skeleton-8 (AuNPs@ZIF-8) as the surface modification materials. The prepared materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to optimize the preparation conditions of activated biochar and the molecularly imprinted polymerization and detection conditions. Under the optimal conditions, the constructed sensors exhibited a wide linear range (2–5 nM,5–120 nM) with a limit of detection (LOD) of 1.84 nM. For real sample detection, the prepared sensor achieved satisfactory results in the detection of pork, chicken and milk samples, and the recovery was between 91.35 % and 108.00 %. The results of this study demonstrate that the sensor had great potential for the detection of norfloxacin in food.