Ochraotoxin [FITC]

This study reports the fabrication of orange peels (OP) extract (water:ethanol:acetonitrile) modified organic-inorganic hybrid bentonite (OP-bentonite). The synthesized composite was employed for the adsorptive removal of carcinogenic mycotoxins (aflatoxin B1 (AFB1), fumonisin B1(FB1) and ochratoxin (OTA)). The product was texturally characterized by BET, FTIR, XRD, TGA, SEM, EDX and XPS techniques while quantification of toxins was performed using HPLC/LC-MS. The effect of reaction temperature, pH, adsorbent dosage, coexisting mycotoxins and gastro-intestinal fluids on the adsorption performance of OP-bentonite was systematically investigated. Isothermal data (pH 2.5 and 7.0) for toxins adsorption agreed well with the Langmuir isotherm model revealing maximum adsorption capacity (q(max)) (mg/g) of 166 and 121 for AFB1, 3.87 and 1.78 for FB1 and 1.97 and 3.19 for OTA respectively. The adsorption kinetics followed pseudo-second-order kinetic model while its adsorption capacity surpassed many adsorbents reported for AFB1, FB1 and OTA with orders of magnitude. Therefore, attributed to the advantages of being efficient, green and simplified synthesis, OP-bentonite could be envisaged as a promising adsorbent for the enhanced sequestration of mycotoxins.

Purpose With the present work, we aimed to assess the occurrence of ochratoxigenic fungi and Ochratoxin A (OTA) in dried grapes from Tunisia. Methods Dried grapes samples (n= 90) were investigated for the presence of ochratoxigenic fungi, which were further characterized at the species level through amplification of the internal transcribed spacer (ITS) region and polymerase chain reaction (PCR) product sequencing. Fungal isolates were tested for their ochratoxigenic potential by high-performance liquid chromatography with fluorescence detection (HPLC-FLD), as well as dried grapes samples after an immunoaffinity column (IAC) clean-up procedure. Results Black Aspergilli isolates were the dominant genre among the filamentous fungi found in dried grapes samples and were the only OTA-producing fungi encountered.Aspergillus nigeraggregate were the most frequently found isolates reaching 70%, 80%, and 85% in dried grapes samples from regions of Kelibia, Sfax, and Rafraf, respectively, while covered 100% of the relevant mycobiota found in imported samples.Aspergillus carbonariusisolates were found only in Sfax's and Kelibia's samples, while uniseriate Aspergilli were found between 7 and 20% in dried grapes from Kelibia, Sfax, and the imported samples. The in vitro OTA production test showed that 88.9% of OTA-producing isolates belonged toA. carbonariuswith OTA levels varying from 0.06 to 1.32 mu g/g of Czapek Yeast Agar (CYA). The remaining OTA-producing fungi (11.1 %) belonged toA. nigeraggregate group having a maximum OTA potential of 2.88 mu g/g CYA, and no uniseriate Aspergilli isolate was able to produce OTA. All dried grapes samples were free of OTA presence. Conclusion According to the present study's findings, no OTA contamination was recorded in the investigated samples from Tunisian market. Nevertheless, the presence of strong OTA producersA. carbonariusin samples originated from the two out of three studied Tunisian regions, as well the high incidences ofAspergillus nigeraggregate group with an attested potential for OTA production in all samples, necessitates further research on Tunisian dried grapes. Additionally, a continuous analysis of staple food of the Mediterranean diet is imperative to insure the best quality for the consumers and prevent potential health problems.