Simultaneous Determination of AFB1 and AFM1 in Milk Samples by Ultra High Performance Liquid Chromatography Coupled to Quadrupole Orbitrap Mass Spectrometry

Application of QuEChERS for Analysis of Contaminants in Dairy Products: A Review

The safety of dairy products is intrinsically linked to consumer health, and the exceedance of risk indicators, such as pesticide and veterinary drug residues, constitutes one of the primary issues affecting their quality and safety. To assess the safety of dairy products, it is crucial to develop accurate and reliable analytical methods for their detection. Food safety testing involving important indicators such as pesticide residues, veterinary drug residues, mycotoxins, and unapproved additives has become a pivotal requirement in the industry field. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method is widely acknowledged as a food safety analysis method currently. This method can effectively extract a wide range of compound classes from diverse matrices in food safety testing, thereby enhancing the accuracy of detection. Additionally, when combined with chromatographic-mass spectrometry techniques, it can simultaneously analyze hundreds of target analytes, rendering it widely applicable in the quality and safety testing of dairy products. Although QuEChERS has rapidly developed in the field of dairy product quality and safety analysis due to its efficiency and speed advantages, certain shortcomings remain, presenting considerable room for improvement. This paper presents a comprehensive review of the utilization and research advancements of the QuEChERS technique in dairy products, with the aim of providing more precise, expeditious, and reliable methods for the safety assessment of dairy products.

Coupling of a streamlined solid-liquid extraction protocol with LC-ESI-MS/MS for the regular oversight of illegal bromate additive use: An accurate and sensitive determination method in preliminary and bakery products

A reliable solid-liquid extraction protocol coupled with liquid chromatography-electrospray ionization-tandem mass spectrometry in the negative-ion mode was developed and validated for illegal bromate determination in preliminary and bakery products. Crude and dried-treated samples were directly extracted with acetonitrile-water (4:1, v/v). Bromate was determined using a Phenomenex Synergi™ Polar reversed-phase column and MS/MS under multiple reaction monitoring. The chosen solvent efficiently extracted bromate with all applied extraction-assisting techniques (p > 0.05). Although this assay avoids cleanup procedures, matrix effect of <-11% was achieved. Rapid bromate separation in only 8 min was attained by a reversed-phase column. In both commodities, linearity range, R2, recovery%, repeatability, intermediate precision, LOD and LOQ results were 0.05-100 ng mL-1, >0.9999, 88.6-103%, 2.93-9.80% and 9.64-10.10%, 0.015 μg kg-1 and 0.05 μg kg-1, respectively. Out of 288 tested real samples, 13.9% of violations were observed. This high-sensitivity protocol offers effective oversight and consumer protection.

Survey of the enniatins and beauvericin in raw and UHT cow's milk in Poland

Introduction

The enniatins A, A1, B and B1 (ENNs) and beauvericin (BEA) are structurally related compounds produced by Fusarium species. They occur as contaminants in cereals, such as wheat, barley and maize. They are called "emerging mycotoxins", because they have been reported in feed and food and their toxic effects are not fully known. Data on their levels in food (especially in milk) are limited. The study aimed to evaluate the occurrence of ENNs and BEA in milk.

Material and Methods

A total of 103 bovine milk samples (76 of raw milk and 27 of UHT milk) were collected from different parts of Poland and analysed using liquid chromatography-tandem mass spectrometry.

Results

Among the 76 raw milk samples, 31 (41%) and 15 (20%) samples were contaminated with ENN B and with BEA, respectively. No contamination with other enniatins was found. The highest concentration of BEA was found in raw milk and was 6.17 μg kg-1. Out of the 27 samples of UHT milk, 16 (59%) were contaminated with ENN B at concentrations ranging from 0.157 μg kg-1 to 0.587 μg kg-1 (limit of quantification (LOQ) 0.098 μg kg-1). Beauvericin was detected in 9 UHT milk samples (33%) at concentrations ranging from 0.101 μg kg-1 to 1.934 μg kg-1 (LOQ 0.095 μg kg-1).

Conclusion

This study demonstrated constant but low milk contamination in Poland with ENN B and BEA. The analysis of milk samples revealed that the emerging mycotoxins ENN B and BEA were measured in trace amounts. It does not suggest any immediate risk to milk consumers; however, it is unknown whether long-term exposure to low levels of toxins may be harmful.

Target analysis and retrospective screening of contaminants in ready-to-eat cooked ham samples through UHPLC-Q-Orbitrap HRMS

The use of veterinary drugs (VDs) is widely administered to animals for both therapeutic and prophylactic purposes. However, their improper use may involve their occurrence in the final products intended for human consumption. In this scientific work, a method for the investigation of target (n = 30) VDs residues and retrospective suspect screening followed by confirmation using analytical standards of others 38 contaminants in ready-to-eat cooked ham by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was developed. The extraction was performed based on the QuEChERS approach and validated in accordance with the European Regulation 2021/808. The application of the in-house validated method to ready-to-eat cooked ham showed the occurrence of fourteen VDs residues. Despite the important incidence, the concentration levels found were below the maximum residue limits set for VDs in porcine muscle, except for colchicine. Constant monitoring of animals derived food is strongly recommended to ensure the food safety of consumers.

Mycotoxins in Raw Bovine Milk: UHPLC-QTrap-MS/MS Method as a Biosafety Control Tool

Mycotoxins are compounds produced by several fungi that contaminate agricultural fields and, either directly or by carry-over, final food products. Animal exposure to these compounds through contaminated feed can lead to their excretion into milk, posing threats to public health. Currently, aflatoxin M1 is the sole mycotoxin with a maximum level set in milk by the European Union, as well as the most studied. Nonetheless, animal feed is known to be contaminated by several groups of mycotoxins with relevance from the food safety point of view that can be carried over into milk. To evaluate the multi-mycotoxin occurrence in this highly consumed food product it is crucial to develop precise and robust analytical methodologies towards their determination. In this sense, an analytical method for the simultaneous identification of 23 regulated, non-regulated, and emerging mycotoxins in raw bovine milk using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) was validated. A modified QuEChERS protocol for extraction purposes was used, and further validation was performed by assessing the selectivity and specificity, limits of detection and quantification (LOD and LOQ), linearity, repeatability, reproducibility, and recovery. The performance criteria were compliant with mycotoxin-specific and general European regulations for regulated, non-regulated, and emerging mycotoxins. The LOD and LOQ ranged between 0.001 and 9.88 ng mL−1 and 0.005 and 13.54 ng mL−1, respectively. Recovery values were between 67.5 and 119.8%. The repeatability and reproducibility parameters were below 15 and 25%, respectively. The validated methodology was successfully applied to determine regulated, non-regulated, and emerging mycotoxins in raw bulk milk from Portuguese dairy farms, proving the importance of widening the monitoring scope of mycotoxins in dairy products. Additionality, this method presents itself as a new strategic and integrated biosafety control tool for dairy farms for the analysis of these natural and relevant human risks.

A Novel Preanalytical Strategy Enabling Application of a Colorimetric Nanoaptasensor for On-Site Detection of AFB1 in Cattle Feed

Aflatoxin contamination of cattle feed is responsible for serious adverse effects on animal and human health. A number of approaches have been reported to determine aflatoxin B1 (AFB1) in a variety of feed samples using aptasensors. However, rapid analysis of AFB1 in these matrices remains to be addressed in light of the complexity of the preanalytical process. Herein we describe an optimization on the preanalytical stage to minimize the sample processing steps required to perform semi-quantitative colorimetric detection of AFB1 in cattle feed using a gold nanoparticle-based aptasensor (nano-aptasensor). The optical behavior of the nano-aptasensor was characterized in different organics solvents, with acetonitrile showing the least interference on the activity of the nan-aptasensor. This solvent was selected as the extractant agent for AFB1-containing feed, allowing for the first time, direct colorimetric detection from the crude extract (detection limit of 5 µg/kg). Overall, these results lend support to the application of this technology for the on-site detection of AFB1 in the dairy sector.

Development of an electrochemical aptasensor based on Au nanoparticles decorated on metal-organic framework nanosheets and p-biphenol electroactive label for the measurement of aflatoxin B1 in a rice flour sample

This study purposes designing a new aptasensor to detect aflatoxin B1 (AFB1). The AFB1 aptasensor was developed by growing gold nanoparticles on the surface of nickel-based metal-organic framework nanosheets (AuNPs/Ni-MOF) and an electroactive indicator (p-biphenol, PBP). The AFB1 aptamer was immobilized on the AuNPs/Ni-MOF and then hybridized with the complementary DNA (cDNA). PBP was intercalated within the double helix of the cDNA-aptamer. The difference between electrochemical responses of intercalated PBP before and after incubation of AFB1 with the immobilized aptamer was considered as an analytical response. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to monitor the construction processes of the aptasensor. By recording the differential pulse voltammograms of PBP in phosphate buffer (pH 7.0, 0.1 M), the linear range and the detection limit of AFB1 were found to be 5.0 × 10^-3-150.0 ng mL^-1 and 1.0 × 10^-3 ng mL^-1 (S/N = 3), respectively. Finally, the designed aptasensor has been successfully used to measure AFB1 in a rice flour sample with satisfying results. Schematic illustrated the different steps of constructing the electrochemical aptasensor based on Au nanoparticles decorated on Ni-metal-organic framework nanosheets and p-biphenol electroactive label for measuring aflatoxin B1 (AFB1).

Development of Gold Nanoparticles Decorated Molecularly Imprinted–Based Plasmonic Sensor for the Detection of Aflatoxin M1 in Milk Samples

Aflatoxins are a group of extremely toxic and carcinogenic substances generated by the mold of the genus Aspergillus that contaminate agricultural products. When dairy cows ingest aflatoxin B1 (AFB1)−contaminated feeds, it is metabolized and transformed in the liver into a carcinogenic major form of aflatoxin M1 (AFM1), which is eliminated through the milk. The detection of AFM1 in milk is very important to be able to guarantee food safety and quality. In recent years, sensors have emerged as a quick, low–cost, and reliable platform for the detection of aflatoxins. Plasmonic sensors with molecularly imprinted polymers (MIPs) can be interesting alternatives for the determination of AFM1. In this work, we designed a molecularly–imprinted–based plasmonic sensor to directly detect lower amounts of AFM1 in raw milk samples. For this purpose, we prepared gold–nanoparticle–(AuNP)−integrated polymer nanofilm on a gold plasmonic sensor chip coated with allyl mercaptan. N−methacryloyl−l−phenylalanine (MAPA) was chosen as a functional monomer. The MIP nanofilm was prepared using the light–initiated polymerization of MAPA and ethylene glycol dimethacrylate in the presence of AFM1 as a template molecule. The developed method enabled the detection of AFM1 with a detection limit of 0.4 pg/mL and demonstrated good linearity (0.0003 ng/mL–20.0 ng/mL) under optimized experimental conditions. The AFM1 determination was performed in random dairy farmer milk samples. Using the analogous mycotoxins, it was also demonstrated that the plasmonic sensor platforms were specific to the detection of AFM1.

Multi-mycotoxin occurrence in feed, metabolism and carry-over to animal-derived food products: A review

The world requests for raw materials used in animal feed has been steadily rising in the last years driven by higher demands for livestock production. Mycotoxins are frequent toxic metabolites present in these raw materials. The exposure of farm animals to mycotoxins could result in undesirable residues in animal-derived food products. Thus, the potential ingestion of edible animal products (milk, meat and fish) contaminated with mycotoxins constitutes a public health concern, since they enter the food chain and may cause adverse effects upon human health. The present review summarizes the state-of-the-art on the occurrence of mycotoxins in feed, their metabolism and carry-over into animal source foodstuffs, focusing particularly on the last decade. Maximum levels (MLs) for various mycotoxins have been established for a number of raw feed materials and animal food products. Such values are sometimes exceeded, however. Aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), trichothecenes (TCs) and zearalenone (ZEN) are the most prevalent mycotoxins in animal feed, with aflatoxin M₁ (AFM1) predominating in milk and dairy products, and OTA in meat by-products. The co-occurrence of mycotoxins in feed raw materials tends to be the rule rather than the exception, and the carry-over of mycotoxins from feed to animal source foods is more than proven.

Cytoprotective Effects of Fish Protein Hydrolysates against H2O2-Induced Oxidative Stress and Mycotoxins in Caco-2/TC7 Cells

Many studies report the potent antioxidant capacity for fish protein hydrolysates, including radical scavenging activity and inhibition ability on lipid peroxidation (LPO). In this study, the in vitro cytotoxicity of protein hydrolysates from different salmon, mackerel, and herring side streams fractions was evaluated in the concentration range from 1 to 1:32 dilution, using cloned human colon adenocarcinoma cells TC7 (Caco-2/TC7) by MTT and PT assays. The protein hydrolysates' antioxidant capacity and oxidative stress effects were evaluated by LPO and reactive oxygen species (ROS) generation, respectively. The antioxidant capacity for pure and bioavailable hydrolysate fraction was also evaluated and compared. Additionally, mycotoxin levels were determined in the fish protein hydrolysates, and their cytoprotective effect against T-2 toxin was evaluated. Both hydrolysates and their bioavailable fraction induced similar cell viability rates. The highest cytoprotective effect was obtained for the salmon viscera protein hydrolysate (HSV), which increased the cell viability by 51.2%. ROS accumulation induced by H₂O₂ and LPO was suppressed by all pure hydrolysates. The cytoprotective effect of hydrolysates was observed against T-2. Moreover, the different fish fraction protein hydrolysates contain variable nutrients and unique bioactive peptide composition showing variable bioactivity, which could be a useful tool in developing dietary supplements with different target functional properties.

Mycotoxin Occurrence and Risk Assessment in Gluten-Free Pasta through UHPLC-Q-Exactive Orbitrap MS

Celiac disease (CD) is a genetic-based autoimmune disorder which is characterized by inflammation in the small intestinal mucosa due to the intolerance to gluten. Celiac people should consume products without gluten, which are elaborated mainly with maize or other cereals. Contamination of cereals with mycotoxins, such as fumonisins (FBs) and aflatoxins (AFs) is frequently reported worldwide. Therefore, food ingestion is the main source of mycotoxin exposure. A new analytical method was developed and validated for simultaneous analysis of 21 mycotoxins in gluten-free pasta, commonly consumed by celiac population as an alternative to conventional pasta. Ultrahigh-performance liquid chromatography coupled to quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Exactive Orbitrap MS) was used for analyte separation and detection. The mycotoxins included in this work were those widely reported to occur in cereal samples, namely, ochratoxin-A (OTA), aflatoxins (AFB1, AFB2, AFG1 and AFG2), zearalenone (ZON), deoxynivalenol (DON), 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol (3-AcDON and 15-AcDON, respectively), nivalenol (NIV), neosolaniol (NEO), fusarenone-X, (FUS-X), T-2 toxin (T-2) and HT-2 toxin (HT-2), fumonisin B1 and B2 (FB1 and FB2, respectively), enniatins (ENN A, ENN A1, ENN B and ENN B1) and beauvericin (BEA). The validated method was successfully applied to 84 gluten-free pasta samples collected from several local markets of Campania region (Italy) during September to November 2020 to monitor the occurrence of mycotoxins and to assess the exposure to these food contaminants. A significant number of samples (95%) showed mycotoxin contamination, being Fusarium mycotoxins (FB1, ZON and DON) the most commonly detected ones. Regarding the risk assessment, the higher exposures were obtained for NIV, DON and FB1 for children and teenagers age group which can be explained due to their lower body weight.

Mycotoxins in Beverages

Mycotoxins are secondary metabolites produced by fungi that contaminate raw materials such as cereals, fruits, dried fruits, coffee, and grapes when they have been produced or maintained in a temperature and/or humidity conditions that favor fungi growth [...]

Detection Methods for Aflatoxin M1 in Dairy Products

Mycotoxins are toxic compounds produced mainly by fungi of the genera Aspergillus, Fusarium and Penicillium. In the food chain, the original mycotoxin may be transformed in other toxic compounds, reaching the consumer. A good example is the occurrence of aflatoxin M1 (AFM1) in dairy products, which is due to the presence of aflatoxin B1 (AFB1) in the animal feed. Thus, milk-based foods, such as cheese and yogurts, may be contaminated with this toxin, which, although less toxic than AFB1, also exhibits hepatotoxic and carcinogenic effects and is relatively stable during pasteurization, storage and processing. For this reason, the establishment of allowed maximum limits in dairy products and the development of methodologies for its detection and quantification are of extreme importance. There are several methods for the detection of AFM1 in dairy products. Usually, the analytical procedures go through the following stages: sampling, extraction, clean-up, determination and quantification. For the extraction stage, the use of organic solvents (as acetonitrile and methanol) is still the most common, but recent advances include the use of the Quick, Easy, Cheap, Effective, Rugged, and Safe method (QuEChERS) and proteolytic enzymes, which have been demonstrated to be good alternatives. For the clean-up stage, the high selectivity of immunoaffinity columns is still a good option, but alternative and cheaper techniques are becoming more competitive. Regarding quantification of the toxin, screening strategies include the use of the enzyme-linked immunosorbent assay (ELISA) to select presumptive positive samples from a wider range of samples, and more reliable methods-high performance liquid chromatography with fluorescence detection or mass spectroscopy-for the separation, identification and quantification of the toxin.

Magnetic Quantum Dot Nanobead-Based Fluorescent Immunochromatographic Assay for the Highly Sensitive Detection of Aflatoxin B1 in Dark Soy Sauce

Herein, we synthesized bifunctional magnetic fluorescent beads (MFBs) with a distinct core/shell structure by encapsulating octadecylamine-coated CdSe/ZnS QDs (OC-QDs) and oleic acid-modified iron oxide nanoparticles (OA-IONPs) into two polymer matrixes with different hydrophobic properties. The OC-QDs and OA-IONPs were mainly distributed in the outer layer of MFBs. The resultant MFBs displayed ca. 226-fold stronger fluorescence emission relative to the corresponding OC-QDs and retained ca. 45.4% of the saturation magnetization of the OA-IONPs. The MFBs were used to purify and enrich aflatoxin B1 (AFB1) from dark soy sauce and then utilized as a fluorescent reporter of immunochromatographic assay (ICA) for the sensitive detection of AFB1. Under the optimal detection conditions, the MFB-based ICA (MFB-ICA) displayed a dynamic linear detection of AFB1 in sauce extract over the range of 5-150 pg/mL with a half maximal inhibitory concentration of 27 ± 3 pg/mL ( n = 3). The detection limits for AFB1 in sauce extract and real dark soy sauce were 3 and 51 pg/mL, respectively, which are considerably better than those of the previously reported fluorescent bead-based ICA methods. The analytical performance of the proposed MFB-ICA in terms of selectivity and accuracy was investigated by analyzing AFB1-spiked dark soy sauce samples. The reliability of the proposed method was further confirmed by ultraperformance liquid chromatography with fluorescence detection. With the combined advantages of QDs and IONPs, the resultant MFBs offer great potential as reporters of ICA for the sensitive detection of trace pollutants in complex matrix samples.

Quantum bead-based fluorescence-linked immunosorbent assay for ultrasensitive detection of aflatoxin M1 in pasteurized milk, yogurt, and milk powder

Herein, we reported a novel direct competitive fluorescence-linked immunosorbent assay (dcFLISA) for the ultrasensitive detection of aflatoxin M₁ (AFM₁) in pasteurized milk, yogurt, and milk powder using 150-nm quantum dot beads (QB) as the carrier of competing antigen. Large QB were applied to decrease the binding affinity of the competing antigen to antibody and enhance the fluorescent signal intensity. The aflatoxin B₁ molecule was used as the surrogate of AFM₁ to label with BSA on the surface of QB because of its 63% cross reaction to anti-AFM₁ mAb. The binding affinity of the competing antigen to mAb was tuned by changing the labeled molar ratios of aflatoxin B₁ to BSA. Through combining the advantages of QB as the carrier of the competing antigen, including low binding affinity to mAb and highly fluorescent signal output, the proposed dcFLISA exhibited an ultrahigh sensitivity for AFM₁ detection, with a half-maximal inhibitory concentration of 3.15 pg/mL in 0.01 M phosphate-buffered saline solution (pH 7.4), which is substantially lower than that of the traditional horseradish peroxidase-based ELISA. The proposed method also exhibited very low detection limitations of 0.5, 0.6, and 0.72 pg/mL for real pasteurized milk, yogurt, and milk powder, respectively. These values are considerably below the maximum permissible level of the European Commission standard for AFM₁ in dairy products. In summary, the proposed dcFLISA offers a novel strategy with an ultrahigh sensitivity for the routine monitoring of AFM₁ in various dairy products.