Residues In Food Research Articles

Inactivation kinetics for surrogates of common foodborne pathogens during food residue drying.

Postconsumer household food residues can act as useful substrates for other industries, but transporting high-moisture material corresponds to high fuel use and associated greenhouse gas production. Drying food residues at the household level reduces transportation weight, increases stability, and preserves the nutritional quality of recovered material. Mitigating foodborne microbiological safety risks is crucial to encourage the development of novel methods to rapidly dry and stabilize food residues. The objective of this study was to improve the prediction of bacterial pathogen inactivation under various thermal and drying processes in a synthetic mixture of residual food material (RFM). The log reduction rate was measured forEscherichia coli, Enterococcus faecium, and Listeria innocua (surrogates of common foodborne pathogens) in RFM under different moisture contents (12% and 25% by fresh weight) and temperatures (50, 55, and 60°C). Inactivation data were used to determine D- and z-values and to fit a multiple regression model to predict log(D-values) in response to temperature and moisture content. Across conditions, D-values were measured to be 5.1-120, 4.6-123, and 32-545min for E. coli, L. innocua, and E. faecium, respectively. Temperature sensitivities were significantly higher in lower moisture RFM for E. coli and L. innocua. Applying E. coli inactivation models during RFM at 55°C yielded inactivation rates that aligned with experimental values after 5min (0.1vs. 0-0.1logs), 30min (2.1vs. 1.3-2.3logs), and 90min (7.2vs. 7.1-8.9logs). These results can inform the design of RFM drying and stabilization processes to promote pathogen inactivation and safety in downstream applications of dried material.

A pioneering electrochemical sensor for the simultaneous determination of nitrofurantoin and furazolidone residues in food and municipal wastewater samples

In this study, a pioneering electrochemical sensor was developed for simultaneously determining nitrofurantoin (NFT) and furazolidone (FZD) residues in food and municipal wastewater samples. The sensor was prepared by integrating gold‑silver-alloy nanocoral clusters (Au-Ag-ANCCs) with zinc oxide nanoparticles (ZnO-NPs), carbon paste electrode (CPE) and polyethylene oxide (PEO) nanocomposites. The surface morphology and elemental compositions of Au-Ag-ANCCs/ZnO-NPs-CPE/PEO were characterized by FT-IR, XRD, SEM, EDX, EIS, and CV. The sensor showed exceptional performance over a wide linear range, from 1.0 pM to 250 μM for NFT and 0.9 nM to 360 μM for FZD. The detection and quantification limits were found to be 0.26 pM and 0.88 pM for NFT and 0.023 pM and 0.076 pM for FZD, respectively. In addition, the sensor exhibited excellent repeatability, reproducibility, selectivity, and long-lasting stability. When applied to the detection of AZM and ENF residues in poultry, fish, honey, dairy products and municipal wastewater, it exhibited excellent recoveries of 96.3–102.8% and relative standard deviations between 1.87% and 1.53%. In general, the developed sensor represents a significant advance in the fight against antibiotic residue pollution.

Assessing external exposome by implementing an Environmental Data Management System using Open Data

Due to the increasing importance of exposome in environmental epidemiology, feasibility and usefulness of an Environmental Data Management System (EDMS) using Open Data was evaluated. The EDMS includes data from 10 European cities (Celje (Slovenia), Łódź (Poland), Manchester (UK), Palermo (Italy), Paris (France), Porto (Portugal), Regensburg (Germany), Reus (Spain), Rijeka (Croatia), Thessaloniki (Greece)) about external non-specific and specific exposome factors at the city or country level (2017–2020). Findings showed that the highest values of life expectancy were in Reus females (86 years) and Palermo males (81 years). UK had the highest obesity rate (28%), Croatia the highest prescribed drug consumption (62%), Greece and Portugal the highest smoking rates (37%, 42%) and daily alcohol consumption (21%), respectively. The most polluted cities were Thessaloniki for PM10 (38 µg/m3), Łódź for PM2.5 (25 µg/m3), Porto for NO2 (62 µg/m3) and Rijeka for O3 (92 µg/m3). Thessaloniki had the highest grey space (98%) and Łódź the highest cumulative amount of pollen (39,041 p/m3). The highest daily noise levels ≥ 55 dB was in Reus (81% to traffic) and Regensburg (21% to railway). In drinking water, arsenic had the highest value in Thessaloniki (6.4 µg/L), boron in Celje (24 mg/L) and lead in Paris (46.7 µg/L). Portugal and Greece showed the highest pesticide residues in food (7%). In conclusion, utilizing open-access databases enables the translation of research findings into actionable strategies for public health interventions.

A Sensitive SERS Sensor Combined with Intelligent Variable Selection Models for Detecting Chlorpyrifos Residue in Tea.

Chlorpyrifos is one of the most widely used broad-spectrum insecticides in agriculture. Given its potential toxicity and residue in food (e.g., tea), establishing a rapid and reliable method for the determination of chlorpyrifos residue is crucial. In this study, a strategy combining surface-enhanced Raman spectroscopy (SERS) and intelligent variable selection models for detecting chlorpyrifos residue in tea was established. First, gold nanostars were fabricated as a SERS sensor for measuring the SERS spectra. Second, the raw SERS spectra were preprocessed to facilitate the quantitative analysis. Third, a partial least squares model and four outstanding intelligent variable selection models, Monte Carlo-based uninformative variable elimination, competitive adaptive reweighted sampling, iteratively retaining informative variables, and variable iterative space shrinkage approach, were developed for detecting chlorpyrifos residue in a comparative study. The repeatability and reproducibility tests demonstrated the excellent stability of the proposed strategy. Furthermore, the sensitivity of the proposed strategy was assessed by estimating limit of detection values of the various models. Finally, two-tailed paired t-tests confirmed that the accuracy of the proposed strategy was equivalent to that of gas chromatography-mass spectrometry. Hence, the proposed method provides a promising strategy for detecting chlorpyrifos residue in tea.

A triple-channel sensor array utilizing fluorescent carbon dots for simultaneous discrimination and detection of multiple fluoroquinolones

The presence of fluoroquinolones (FQs) residues in food and the environment has prompted concerns regarding food safety and public health. Consequently, it is of great significance to analyze the types and levels of FQs present. However, the majority of studies have concentrated on the specific detection of individual FQs, with a notable absence of high-throughput and rapid analysis methods for the simultaneous detection of multiple FQs that may coexist in food and the environment. Hereon, a triple-channel sensor array was successfully constructed utilizing fluorescent carbon dots (TA-CDs), with the assistance of Cu2+ and Fe3+, for the qualitative discrimination and quantitative detection of eight types of FQs. The sensor array can distinguish between different concentrations of FQs and various mixtures of FQs, as well as 100 % accuracy in the discrimination of unknown samples. Impressively, the sensor platform can quantitatively detect FQs in animal-derived foods, such as honey, milk, eggs, and pork, as well as in water samples. This research has the potential to be extended to other analytes with similar chemical structures or properties.

Custom-printed microfluidic chips using simultaneous ratiometric fluorescence with "Green" carbon dots for detection of multiple antibiotic residues in pork and water samples.

In the evolving field of food safety, rapid and precise detection of antibiotic residues is crucial. This study aimed to tackle this challenge by integrating advanced inkjet printing technology with sophisticated microfluidic paper-based analytical devices (µPADs). The µPAD design utilized "green" quantum dots synthesized via an eco-friendly hydrothermal method using green white mulberry leaves as the carbon source, serving as the key fluorescent detection material. The action mechanism involved a photoinduced electron transfer system using red carbon dots (CDs) as electron donors and blue CDs combined with two-dimensional layered molybdenum disulfide (MoS2) nanosheets as electron acceptors. This system could quickly detect antibiotics within 10min in pork and water samples, demonstrating high sensitivity and recovery rates: 6.5pmol/L at 99.75%-110% for sulfadimethoxine, 3.3pmol/L at 99%-105% for sulfamethoxazole, and 8.5pmol/L at 98.5%-105% for tetracycline. It achieved a relative standard deviation under 5%, ensuring reliability and reproducibility. The fabricated sensor offered a promising application for the rapid and efficient on-site detection of antibiotic residues in food.

Detection and adsorption of florfenicol in milk using bifunctional carbon dot-doped molecularly imprinted polymers.

Detection of florfenicol (FF) residues in animal-derived foods, as one of the most widely used antibiotics, is critically important to food safety. The fluorescent molecularly imprinted polymer (MIP) was synthesized by surface-initiated atom transfer radical polymerization technique with poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres, 4-vinylpyridine, ethylene glycol dimethacrylate, and FF as the matrix, functional monomer, crosslinker, and template molecule, respectively. Meanwhile, N-S co-doped carbon dot (CD) was synthesized with triammonium citrate and thiourea as precursors under microwave irradiation at 400W for 2.5min and then integrated into FF-MIP to obtain CD@FF-MIP. For comparison, non-imprinted polymer (NIP) without FF was also prepared. The adsorption capacity of CD@FF-MIP to FF reached 53.1mgg-1, which was higher than that of FF-MIP (34.7mgg-1), whereas the adsorption capacity of NIP was only 17.3mgg-1. The adsorption equilibrium of three materials was reached within 50min. Particularly, CD@FF-MIP exhibited an excellent fluorescence quenching response to FF in the concentration range of 3-50 µmolL-1. As a result, CD@FF-MIP was successfully utilized to extract FF in milk samples, which were analyzed by high-performance liquid chromatography. The standard recoveries were 95.8%-98.2%, and the relative standard deviation was 1.6%-4.2%. The method showed the advantages of simple operation, high sensitivity, excellent selectivity, and low cost, and also demonstrated a great application prospect in food detection.

Screening and Simultaneous Determination of 80 Veterinary Drug Residues in Food by HPLC-MS/MS

Screening and Simultaneous Determination of 80 Veterinary Drug Residues in Food by HPLC-MS/MS

Rapid analysis of salbutamol residues in animal-derived food based on the fluorescence of MOFs/MIPs paper-based chips

Mimetic recognition materials for rapid and selective analysis of foodborne contamination from complex foodstuff becomes a hot research topic in the field of food safety. In this work, borate-affinity-functionalized MOF/molecularly imprinted polymer paper-based microfluidic chips (FSU-BA@MIP) were prepared by growing functionalized MOFs on paper surface with 3-carboxyphenylboronic acid (3-CPBA) as the ligands, followed by coating of a MIP layer of salbutamol (SAL) through a borate-affinity surface imprinting strategy. Using the obtained paper-based chip as a mimetic recognition and specific enrichment module, the fluorescence sensing platform achieved visual rapid quantitative analysis of SAL with a linear range of 0.1 × 10−2–5.0 mg L−1. The limits of detection and quantification were calculated to be 0.095 and 0.290 μg kg−1, respectively, and the sample loading via lateral flow aid could be completed within 30 min. The obtained MOFs/MIPs paper chips provide an effective way for the rapid analysis of harmful contaminants from different animal-derived foods.

Magnetic Immunoassay Based on Au Pt Bimetallic Nanoparticles/Carbon Nanotube Hybrids for Sensitive Detection of Tetracycline Antibiotics.

Misusage of tetracycline (TC) antibiotics residue in animal food has posed a significant threat to human health. Therefore, there is an urgent need to develop highly sensitive and robust assays for detecting TC. In the current study, gold and platinum nanoparticles were deposited on carbon nanotubes (CNTs) through the superposition method (Au@Pt/CNTs-s) and one-pot method (Au@Pt/CNTs-o). Au@Pt/CNTs-s displayed higher enzyme-like activity than Au@Pt/CNTs-o, which were utilized for the development of sensitive magnetic immunoassays. Under the optimized conditions, the limits of detection (LODs) of magnetic immunoassays assisted by Au@Pt/CNTs-s and Au@Pt/CNTs-o against TCs could reach 0.74 ng/mL and 1.74 ng/m, respectively, which were improved 6-fold and 2.5-fold in comparison with conventional magnetic immunoassay. In addition, the measurement of TC-family antibiotics was implemented by this assay, and ascribed to the antibody used that could recognize TC, oxytetracycline, chlortetracycline, and doxycycline with high cross-reactivity. Furthermore, the method showed good accuracy (recoveries, 92.1-114.5% for milk; 88.6-92.4% for pork samples), which also were applied for determination of the targets in real samples. This study provides novel insights into the rapid detection of targets based on high-performance nanocatalysts.

Is it necessary to stop glucagon-like peptide-1 receptor agonists prior to endoscopic procedure? A retrospective study.

Glucagon-like peptide-1 receptor agonists (GLP-1 RA) are effective in diabetes and obesity, reducing hyperglycemia by increasing insulin release and delaying gastric emptying. However, they can cause gastroparesis, raising concerns about aspiration during procedures. Recent guidelines advise discontinuing GLP-1 RA before surgery to reduce the risk of pulmonary aspiration. To evaluate the effect of GLP-1 RAs on gastric residual contents during endoscopic procedures. A retrospective chart review at BronxCare Health System, New York, from January 2019 to October 2023, assessed gastric residue and aspiration in GLP-1 RA patients undergoing endoscopic procedures. Two groups were compared based on dietary status before the procedure. Data included demographics, symptoms of gastroparesis, opiate use, hemoglobin A1c, GLP-1 agonist indication, endoscopic details, and aspiration occurrence. IBM SPSS was used for analysis, calculating means, standard deviations, and applying Pearson's chi-square and t-tests for associations, with P < 0.05 as being significant. During the study, 306 patients were included, with 41.2% on a clear liquid/low residue diet and 58.8% on a regular diet before endoscopy. Most patients (63.1%) were male, with a mean age of 60 ± 12 years. The majority (85.6%) were on GLP-1 RAs for diabetes, and 10.1% reported digestive symptoms before endoscopy. Among those on a clear liquid diet, 1.5% had residual food at endoscopy compared to 10% on a regular diet, which was statistically significant (P = 0.03). Out of 31 patients with digestive symptoms, 13% had residual food, all from the regular diet group (P = 0.130). No complications were reported during or after the procedures. The study reflects a significant rise in GLP-1 RA use for diabetes and obesity. A 24-hour liquid diet seems safe for endoscopic procedures without aspiration. Patients with upper gastrointestinal symptoms might have a higher residual food risk, though not statistically significant. Further research is needed to assess risks based on diabetes duration, gastroparesis, and GLP-1 RA dosing, aiming to minimize interruptions in therapy during procedures.

Comparison of nitrogen and helium as carrier gases for determination of pesticide residues in foods via gas chromatography–tandem mass spectrometry with atmospheric pressure chemical ionization

The applicability of nitrogen as an alternative carrier gas to helium for the multiresidue analysis of pesticides using gas chromatography–tandem mass spectrometry with atmospheric pressure chemical ionization (GC–(APCI)MS/MS) was examined. The methods using both carrier gases were validated for 151 pesticides in foods at a spiking level of 0.01 ppm, maintaining identical conditions for both gases, including the GC column and carrier gas flow rate. The use of nitrogen resulted in slightly broader peaks and lower peak intensities that those observed upon using helium. However, sufficient sensitivity was achieved for all target compounds because of the high sensitivity of the GC–(APCI)MS/MS method. Further, target-compound separation was not significantly affected by the carrier gas type, and no interfering peaks were observed, demonstrating the high selectivity of the nitrogen-based method, even beyond the optimum linear velocity. Finally, the analytical performance of the nitrogen-based method was comparable to those of the helium-based method. Considering cost-effectiveness of nitrogen, this method is highly valuable in the event of helium shortages and for routine pesticide residue monitoring.

Highly sensitive detection of environmental toxic fenitrothion in fruits and water using a porous graphene oxide nanosheets based disposable sensor

Monitoring fenitrothion (FNT) residues in food and the environment is crucial due to its high environmental toxicity. In this study, we developed a sensitive, reliable electrochemical method for detecting FNT by using screen-printed carbon electrodes (SPCE) modified with porous graphene oxide (PGO) nanosheets. PGO surface properties have been meticulously characterized using advanced spectroscopic techniques. Electrochemical impedance spectroscopy and cyclic voltammetry were used to test the electrochemical properties of the PGO-modified sensor. The PGO-modified sensor exhibited remarkable sensitivity, achieving a detection limit as low as 0.061 μM and a broad linear range of 0.02–250 μM. Enhanced performance is due to PGO's high surface area and excellent electrocatalytic properties, which greatly improved electron transfer. Square wave voltammetry was used to demonstrate the sensor's efficacy as a real-time, on-site monitoring tool for FNT residues in fruit and water. The outstanding performance of the PGO/SPCE sensor underscores its applicability in ensuring food safety and environmental protection.

Advancing Sustainable Agriculture: A Comprehensive Review of Organic Farming Practices and Environmental Impact

Organic farming, characterized by the exclusion of synthetic fertilizers and chemical pesticides, represents a sustainable approach to agriculture. This study investigates the impact of organic farming practices on soil health, focusing on the proliferation and activity of soil microorganisms. Natural fertilizers such as farmyard manure, poultry litter, composts, green manures, and oil-free cakes were utilized to enhance soil fertility. The research reveals that these practices significantly improve soil health by fostering a robust microbiome, which is essential to the cycling of nutrients and overall health of the soil vitality. The safety and nutritional benefits of organic food products were also evaluated. Comparative analysis with conventionally grown foods indicates that organic produce contains lower levels of harmful residues such as pesticides, nitrates, metals, and antibiotics. This reduction in contaminants mitigates potential risks to human health associated with conventional farming practices. Furthermore, organic foods are found to be richer in essential nutrients, vitamins, and antioxidants, thereby offering superior nutritional value. The economic implications of organic farming were explored, highlighting its potential to enhance the economic viability of small-scale farmers. With increasing consumer awareness and demand for organic products, farmers practicing organic methods can command higher prices for their produce, thereby improving their economic sustainability and resilience. In conclusion, organic farming emerges as an environmentally friendly and economically viable alternative to conventional agriculture. By promoting soil health, reducing chemical residues in food, and meeting consumer demand for nutritious products, organic farming offers a pathway towards sustainable agricultural practices.

Pesticide residues in food of plant origin commercialized in Brazil from 2010 to 2020 – An update from the two national monitoring programs

The objective of this study was to investigate the results of the two Brazilian national pesticide residue monitoring programs obtained from January 2010 to December 2020. A total of 35,321samples of 44 different food crops were analyzed, of which 55.3% tested positive for at least one compound, with pear, peach, strawberry and sweet pepper having over 90% of the analyzed samples containing residues. Approximately one-third of the positive samples had at least one irregularity, of which 86.7% due to the presence of non-authorized pesticides for the crop, 26.3% exceeding the maximum residue level, and 13.1% showing both irregularities. A total of 191 different compounds were detected, primarily organophosphorus (OP) (37.4% of positive samples, of which over 60% of cereal/flour, potatoes, and peanuts). Chlorpyrifos, acephate, pirimiphos-methyl, and methamidophos were the main OPs detected. Triazoles were present in 27.2% of the positive samples, mainly rice, and pyrethroids in 22.4% of the positive samples, mainly in popcorn. Dithiocarbamates were present in 19.7% of the positive samples, predominantly in apples, and 5.0% of the positive samples contained N-methyl carbamates, mainly in sweet peppers. Carbendazim was the most detected pesticide (30% of positive samples), mainly in papaya (18.2% of samples containing this pesticide). About 60% of positive samples contained multiple residues, primarily in sweet pepper, pear, strawberry, and orange (over 80% of positive samples). Compared to the previous decade (2001–2010), these results indicated increased percentages of positive, irregular and of samples containing multiple residues. Dithiocarbamates were no longer the most detected pesticide group, while carbendazim remained the most detected pesticide in both periods.

Biogas production performance using soybean residue and hydrothermal pretreated food waste hydrolysate in a continuously anaerobic two-stage pilot plant

In this study, a continuously anaerobic two-stage pilot plant was established for bioenergy production, comprising 5 major pieces of equipment: a mixing tank, 1st anaerobic digester (AD), 2nd AD, sediment tank, aeration tank, and final sediment tank, all operating at ambient conditions. The operation of the continuously anaerobic two-stage pilot plant was automatically controlled by a programmable logic controller (PLC) using a designed control logic concept to set the hydraulic retention time (HRT) and inlet substrate concentration. The organic loading rate, pretreatment of hydrolysis pressure, and microbial community analysis were investigated for their effects on biogas production performance using different substrates: soybean residue (SR) and food waste hydrolysate (FWH), respectively. It was found that the peaks of biogas production rate on daily volumetric feeding were 1.20 m³·m⁻³·d⁻1, and the biogas yield on VS added was 760 dm³·kg⁻1 from food waste hydrolysate with a pretreatment hydrolysis pressure of 10 kg cm⁻2, at an OLR in COD concentration of 3.56 kg m⁻³·d⁻1, and an HRT of 11 days, respectively. The Methanobrevibacter genus was found to be abundant in the 1st AD, approximately 6.7 times more abundant than in the 2nd AD. The continuous anaerobic two-stage pilot plant was properly examined for its application in treating food waste and soybean residue with the goal of obtaining renewable bioenergy.

Enterobacteriaceae Antibiotic Resistance Identification in Slender-billed Gull Species Migrating to Libya

The Libyan coast has various types of wetlands that are passed by many migratory birds throughout the year, however, studies on bacterial isolation from these birds in Lybia are scarce. The present study aimed to isolate enteropathogenic bacterial species from the seagulls that migrated to the Libyan coast as well as identification of the antibiotics that are resistant to these bacteria. A total of 50 fresh fecal samples were collected from slender-billed gulls in January 2023 at Farwa Island near the city of Zuwara, in Western Libya. Bacteria were isolated by conventional culturing method, identified using the Enterosystem 18R, and antibiotic susceptibility tests were conducted on the isolated bacteria. The results revealed the isolation of 46 bacteria, but only 32 of them were identified using biochemical tests. These identified bacteria belong to six species of Enterobacteriacae, namely Citrobacter (C.) freundii, Pantoea (P.) agglomerans, Escherichia (E.) coli, Enterobacter (En.) cloacae, Serratia liquifaciens, and Proteus mirabilis, with percentages of 53.125%, 31.25%, 6.25%, 3.125%, 3.125%, and 3.125%, respectively. All isolated bacteria were 100% sensitive to gentamicin (10 µg) and ciprofloxacin (5 µg). The highest resistance result was observed against the antibiotic cefoxitin (30 µg), with both C. freundii (5 samples) and P. agglomerans (4 samples). Resistance was observed in 5 samples of C. freundii and 4 samples of P. agglomerans out of 11 samples. Resistance to antibiotics, such as azithromycin (15 µg), ceftriaxone (30 µg), and ampicillin (10 µg), was also noted in a few isolates. The results indicated that C. freundii was the most antibiotic-resistant bacterial species isolated in this study. The highest multiple antibiotic resistance index was demonstrated by bacteria C. freundii, P. agglomerans, and En. cloacae, with a value of 0.33 for each of them. In conclusion, slender-billed gulls carry multi-drug-resistant bacteria. The study recommends the implementation of a national program to survey antibiotic-resistant bacteria, determine their prevalence, and assess the presence of antibiotic residues in animal-derived food. Furthermore, the present study advises expanding scientific studies on risk analysis, and antibiotic alternatives in migratory birds.

Borax attenuates oxidative stress, inflammation, and apoptosis by modulating Nrf2/ROS balance in acrylamide-induced neurotoxicity in rainbow trout

Acrylamide (ACR) can have adverse environmental effects because of its multiple applications. Relevant scientific literatures of the existence of ACR residues in foods following processing steps have raised concern in the biochemistry, chemistry and safety of this vinyl substance. The interest has focused on the hepatotoxicity of ACR in animals and humans and on the ACR content mitigation and its detoxification. Borax (BX), as a naturally occurring antioxidant featured boron compound, was selected in this investigation to assess its possible neuro-protective potential against ACR-induced neurotoxicity. Nrf2 axis signaling pathways and detoxification response to oxidative stress after exposure to ACR in brains of rainbow trout, and the effect of BX application on reducing ACR-induced neurotoxicity were investigated. Rainbow trout were acutely exposed to ACR (12.5 mg/L) alone or simultaneously treated with BX (0.75 mg/L) during 96h. The exposed fish were sampled at 48th and 96th and oxidative stress response endpoints, 8-OHdG, Nrf2, TNF-α, caspase-3, in addition to IL-6 activities and the levels of AChE and BDNF in brain tissues of rainbow trout (Oncorhynchus mykiss) were evaluated. Samples showed decreases in the levels of ACR-mediated biomarkers used to assess neural toxicity (SOD, CAT, GPx, AChE, BDNF, GSH), increased levels of MDA, MPO, DNA damage and apoptosis. ACR disrupted the Nrf2 pathway, and induced neurotoxicity. Inhibited activities’ expressions under simultaneous administration experiments, revealed the protective effects of BX against ACR-induced toxicity damage. The obtained data allow the outline of early multi-parameter signaling pathways in rainbow trout

Visual Analysis of Carbendazim Residues in Carrot Tubers via Postionization Mass Spectrometry Imaging

Carbendazim (CBZ) residues in food are a severe threat to food safety, and their detection is a challenging problem in food science. We introduce here a new method based on laser desorption postionization mass spectrometry imaging (LDPI-MSI) for detecting CBZ residues in carrots. In the novel LDPI-MSI method, two distinct laser beams simultaneously exert dissociation and ionization, which offers several advantages over traditional techniques based on single-photon matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), including simplified sample preparation, streamlined operation workflow, and a lower limit of detection (LOD). The LOD, in the proposed method, has been lowered to 0.019 ppm. Coupled with mass spectrometry imaging (MSI), the LDPI-MS method enabled in situ detection of small molecular compounds, such as chemical pesticides, and provided comprehensive and accurate results. The image obtained from the characteristic mass spectrometric signature of CBZ at m/z 191 illustrated that most of the CBZ could not enter the carrot tubers directly, but a small amount of CBZ entered the carrot root and was mainly concentrated in the central xylem. The results suggest that the proposed method could potentially be used in pesticide analysis.

Highly sensitive antibiotic sensing based on optical weak value amplification: A case study of chloramphenicol

The public health concern of antibiotic residues in animal-origin food has been a long-standing issue. In this work, we present a novel method for antibiotic detection, leveraging optical weak value amplification and harnessing an indirect competitive inhibition assay, which significantly boosts the system's sensitivity in identifying small molecule antibiotics. We chose chloramphenicol as a model compound and mixed it with chloramphenicol-bovine serum albumin conjugates to bind to the chloramphenicol antibody competitively. We achieved a broad linear detection range of up to 3.24 ng/mL and a high concentration resolution of 33.20 pg/mL. To further validate the universality of our proposed detection methodology, we successfully applied it to testing gibberellin and tetracycline. Moreover, we conducted regeneration experiments and real-sample correlation studies. This study introduces a novel strategy for the label-free optical sensing of small molecule antibiotics, greatly expanding the range of applications for sensors utilizing optical weak value amplification.