Assessment of multi-mycotoxin contamination throughout the supply chain of maize-based poultry feed from selected regions of Malaysia by LC-MS/MS

Development of an immunoassay for the detection of mycotoxins using xMAP technology and its evaluation in black tea samples

Mycotoxins, a natural food contaminant, are secondary metabolites of fungi. Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are two major mycotoxins found in various food commodities. These mycotoxins are hepatotoxic, nephrotoxic, cytotoxic, mutagenic and carcinogenic, thus they are a public health concern and their monitoring in food commodities is necessary. There are several conventional techniques available for mycotoxin detection, such as HPLC, LCMS, and ELISA. However, extensive nature and huge cost allowances make it challenging to deploy these techniques for monitoring of mycotoxins in the large sample size. Therefore, a robust, responsive and high-throughput technique is required. Here, we aimed to develop a multiplexed Luminex suspension assay based on multi analyte profiling (xMAP) technology for the simultaneous detection of AFB1 and OTA in the black tea, which is found to be contaminated with these mycotoxins during the cultivation or processing steps. Limit of detection for AFB1 and OTA, was 0.06 ng/ml and 0.49 ng/ml, respectively without any cross-reactivity with other mycotoxins and this assay is suitable for simultaneous detection of AFB1 and OTA in the same sample. Collectively, based on the results, we suggest that the developed Luminex suspension assay is sensitive, accurate, rapid and suitable for high-throughput screening of multiple mycotoxins.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05848-3.

Evaluation of reduced graphene oxide-based nanomaterial as dispersive solid phase extraction sorbent for isolation and purification of aflatoxins from poultry feed, combined with UHPLC-MS/MS analysis

Poultry feed comprises cereals and their by-products and is vulnerable to aflatoxins contamination. This study utilised reduced graphene oxide-titanium dioxide (rGO-TiO2) nanomaterial as a dispersive solid phase extraction (d-SPE) adsorbent to extract, enrich and purify aflatoxins (aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2). The synthesis of rGO-TiO2 nanomaterials through hydrothermal process and characterisation by transmission electron microscopy, scanning electron microscopy, Brunauer-Emmett-Teller (BET) and X-ray diffraction reveals that the nanomaterials have a single-layer structure embedded with TiO2 nanoparticles. The matrix-spiked technique was employed for the extraction process, optimisation of d-SPE, and analytical method validation. The most appropriate extraction solvent was acetonitrile/water/formic acid (79/20/1, v/v/v), with 30 min of extraction time assisted by ultra-sonication. The optimised d-SPE parameters were: 50 mg of rGO-TiO2 as sorbent amount, 2% methanol as the sample loading solvent, 30 min as adsorption time, and absolute ethanol as the washing reagent. The d-SPE method exhibited good desorption efficiency with 3 mL of acetonitrile/formic acid (99/1, v/v) and 20 min desorption time. After validation, the UHPLC-MS/MS analytical method has an acceptable range of specificity, linearity (R2 ≥ 0.999), sensitivity (LOQ 0.04-0.1 µg kg-1), recoveries (74-105% at three matrix-spiked levels) and precision (RSD 1.5-9.6%). Poultry feed samples (n = 12) were pretreated by this method to extract, enrich and analyse aflatoxins, which were detected in all poultry feed samples. The contamination levels were within the permissible limits.

Deoxynivalenol Degradation by Various Microbial Communities and Its Impacts on Different Bacterial Flora

Deoxynivalenol, a mycotoxin that may present in almost all cereal products, can cause huge economic losses in the agriculture industry and seriously endanger food safety and human health. Microbial detoxifications using microbial consortia may provide a safe and effective strategy for DON mitigation. In order to study the interactions involving DON degradation and change in microbial flora, four samples from different natural niches, including a chicken stable (expJ), a sheep stable (expY), a wheat field (expT) and a horse stable (expM) were collected and reacted with purified DON. After being co-incubated at 30 °C with 130 rpm shaking for 96 h, DON was reduced by 74.5%, 43.0%, 46.7%, and 86.0% by expJ, expY, expT, and expM, respectively. After DON (0.8 mL of 100 μg/mL) was co-cultivated with 0.2 mL of the supernatant of each sample (i.e., suspensions of microbial communities) at 30 °C for 96 h, DON was reduced by 98.9%, 99.8%, 79.5%, and 78.9% in expJ, expY, expT, and expM, respectively, and was completely degraded after 8 days by all samples except of expM. DON was confirmed being transformed into de-epoxy DON (DOM-1) by the microbial community of expM. The bacterial flora of the samples was compared through 16S rDNA flux sequencing pre- and post the addition of DON. The results indicated that the diversities of bacterial flora were affected by DON. After DON treatment, the most abundant bacteria belong to Galbibacter (16.1%) and Pedobacter (8.2%) in expJ; Flavobacterium (5.9%) and Pedobacter (5.5%) in expY; f_Microscillaceae (13.5%), B1-7BS (13.4%), and RB41 (10.5%) in expT; and Acinetobacter (24.1%), Massilia (8.8%), and Arthrobacter (7.6%) in expM. This first study on the interactions between DON and natural microbial flora provides useful information and a methodology for further development of microbial consortia for mycotoxin detoxifications.