First report on the metabolic characterization of Sterigmatocystin production by select Aspergillus species from the Nidulantes section in Foeniculum vulgare.

Spices are typically grown in climates that support the growth of toxigenic fungi and the production of mycotoxins. The Aspergilli described in this study, as well as the sterigmatocystin (STC) detected, are causes for concern due to their potential to induce food poisoning. One of the most well-known producers of the carcinogenic STC is Aspergillus nidulans. This research explores the occurrence of STC-producing fungi in Foeniculum vulgare, a spice that is marketed in India and other parts of the world. This innovative study details the mycotoxigenic potential of five Aspergilli belonging to Section Nidulantes, namely Aspergillus latus (02 isolates), Emericella quadrilineata (02 isolates), and Aspergillus nidulans (01 isolate), with respect to STC contamination. These five isolates of Aspergilli were screened to produce STC on yeast extract sucrose (YES) medium in a controlled environment with regard to light, temperature, pH, and humidity, among other variables. The expression patterns of regulatory genes, namely, aflR, laeA, pacC, fluG, flbA, pksA, and mtfA were studied on the Czapek-Dox agar (CDA) medium. STC biosynthesis by the test isolates was done in potato dextrose broth (PDB) under optimum conditions, followed by the extraction and purification of the broth using ethyl acetate. High-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector was utilized to detect compounds in eluted samples. F. vulgare contains Aspergilli that have been shown to have mycotoxigenic potential, which can accumulate in the spice during its active growth and thereby cause the elaboration of mycotoxins.

High-Throughput Analysis of Aflatoxins in Cereals, Nuts, and Processed Products Involving Automated Immunoaffinity Cleanup and Inline HPLC-Fluorescence Detection.

BACKGROUND: The testing of aflatoxins (AFs) in fresh and processed foods is highly in demand to comply with trade regulations. Consequently, commercial laboratories face huge AF sample loads in food consignments. Worldwide, there is a rising interest in implementing automation to increase sample throughput in AF analysis. OBJECTIVE: This study sought to evaluate the performance of an automated cleanup and HPLC analysis system for determination of regulated AFs (B1, B2, G1, G2) in rice, flattened rice, sorghum, raw and processed peanut, almond, peanut butter, and wheat-based cookies. METHODS: The samples were extracted with methanol-water (80:20), diluted with Triton X-100, and subjected to automated analysis, where the cleanup step through immunoaffinity column (IAC) and HPLC-fluorescence analyses (involving postcolumn bromination-derivatization) were performed in 10 and 11 min, respectively. The method was validated in all test matrices at the LOQ and higher levels. The method performance was also evaluated against a conventional workflow where cleanup and HPLC analysis were manually performed. RESULTS: The LOQ for peanut, sorghum, rice, and flattened rice was 0.125 ng/g, while it was 0.5 ng/g for peanut butter, almond, and wheat-based cookies. In all matrices, the recoveries at LOQ and higher levels were satisfactory. The double-cartridge exchange system completed the analysis of ∼96 injections in 18 h. Each IAC could be reused 15 times without incurring any recovery loss. The automated system provided a better precision (RSD < 9%) than the conventional workflow (RSD = 12-15%). CONCLUSIONS: Because of its high-throughput nature, this method is recommended for routine analysis of AFs. HIGHLIGHTS: A high-throughput method is reported where cleanup and HPLC analysis of AFs were automatically performed. Each IAC could be used 15 times without any loss of recovery. The method performance was better than the conventional approach and complied with the analytical quality control guidelines.

Multi-residue analysis of captan, captafol, folpet, and iprodione in cereals using liquid chromatography with tandem mass spectrometry.

In this study, we propose an improved analytical method for the multiresidue analysis of captan (plus its metabolite, tetrahydrophthalimide), folpet (plus its metabolite, phthalimide), captafol, and iprodione in cereals using liquid chromatography tandem mass spectrometry (LC-MS/MS). As captan, captafol, and folpet are easily degraded during homogenisation and extraction, samples were comminuted with liquid nitrogen, and both QuEChERS and ethyl acetate-based extraction workflows provided a satisfactory method performance. The optimised LC-MS/MS procedure with electrospray ionisation did not degrade these compounds, and offered sufficient method selectivity by resolving and minimising co-eluting matrix-derived interferences. The method also resolved the problem of non-specific mass spectra that these compounds usually produce on GC-MS analysis involving electron ionisation. The method performance was satisfactory for all 6 compounds at 0.01 mg kg-1 and higher levels of fortification, and validated as per the SANTE/11813/2017 guidelines of analytical quality control in a wide range of cereals including rice, wheat, sorghum, and corn. The method provides special advantage of simultaneous analysis of captan, and folpet along with their metabolites (tetrahydrophthalimide, and phthalimide, respectively) in combination with captafol, and iprodione in a single chromatographic run. Although iprodione is known to degrade to 3,5-dichloroaniline, since this metabolite is not a part of the residue definition, it was not included in the scope of this method. As the method demonstrates satisfactory selectivity, sensitivity, accuracy, precision, and robustness in a wide range of cereal matrices, it is recommended for regulatory testing of these compounds in cereals.