MycotoxinDB: A Data-Driven Platform for Investigating Masked Forms of Mycotoxins.

Mycotoxins are likely to be converted into masked forms when subjected to plant metabolism or food processing. These masked forms of mycotoxins together with their prototypes may cause mixture toxicity effects, causing adverse effects on animal welfare and productivity. The structure elucidation of masked mycotoxins is the most challenging task in mycotoxin research due to the limitations of traditional analysis methods. To assist in the rapid identification of masked mycotoxins, we developed a data-driven online prediction tool, MycotoxinDB, based on reaction rules. Using MycotoxinDB, we identified seven masked DONs from wheat samples. Given its widespread applications, we expect that MycotoxinDB will become an indispensable tool in future mycotoxin research. MycotoxinDB is freely available at: http://www.mycotoxin-db.com/.

Mycotoxins Contamination in Rice: Analytical Methods, Occurrence and Detoxification Strategies.

The prevalence of mycotoxins in the environment is associated with potential crop contamination, which results in an unavoidable increase in human exposure. Rice, being the second most consumed cereal worldwide, constitutes an important source of potential contamination by mycotoxins. Due to the increasing number of notifications reported, and the occurrence of mycotoxins at levels above the legislated limits, this work intends to compile the most relevant studies and review the main methods used in the detection and quantification of these compounds in rice. The aflatoxins and ochratoxin A are the predominant mycotoxins detected in rice grain and these data reveal the importance of adopting safety storage practices that prevent the growth of producing fungi from the Aspergillus genus along all the rice chain. Immunoaffinity columns (IAC) and QuECHERS are the preferred methods for extraction and purification and HPLC-MS/MS is preferred for quantification purposes. Further investigation is still required to establish the real exposition of these contaminants, as well as the consequences and possible synergistic effects due to the co-occurrence of mycotoxins and also for emergent and masked mycotoxins.

The Occurrence and Co-Occurrence of Regulated, Emerging, and Masked Mycotoxins in Rice Bran and Maize from Southeast Asia.

Raw feed materials are often contaminated with mycotoxins, and co-occurrence of mycotoxins occurs frequently. A total of 250 samples i.e., rice bran and maize from Cambodia, Laos, Myanmar, and Thailand were analysed using state-of-the-art liquid chromatography-mass spectrometry (LC-MS/MS) for monitoring the occurrence of regulated, emerging, and masked mycotoxins. Seven regulated mycotoxins - aflatoxins, ochratoxin A, fumonisin B1, deoxynivalenol, zearalenone, HT-2, and T-2 toxin were detected as well as some emerging mycotoxins, such as beauvericin, enniatin type B, stachybotrylactam, sterigmatocystin, and masked mycotoxins, specifically zearalenone-14-glucoside, and zearalenone-16-glucoside. Aspergillus and Fusarium mycotoxins were the most prevalent compounds identified, especially aflatoxins and fumonisin B1 in 100% and 95% of samples, respectively. Of the emerging toxins, beauvericin and enniatin type B showed high occurrences, with more than 90% of rice bran and maize contaminated, whereas zearalenone-14-glucoside and zearalenone-16-glucoside were found in rice bran in the range of 56-60%. Regulated mycotoxins (DON and ZEN) were the most frequent mycotoxin combination with emerging mycotoxins (BEA and ENN type B) in rice bran and maize. This study indicates that mycotoxin occurrence and co-occurrence are common in raw feed materials, and it is critical to monitor mycotoxin levels in ASEAN's feedstuffs so that mitigation strategies can be developed and implemented.

Intestinal hydrolysis and microbial biotransformation of diacetoxyscirpenol-α-glucoside, HT-2-ß-glucoside and N-(1-deoxy-d-fructos-1-yl) fumonisin B1 by human gut microbiota in vitro.

Fusarium mycotoxins are common contaminants in cereals and often co-occur with plant-derived mycotoxin sugar conjugates. Several of these modified mycotoxins are not degraded in the small intestine and hence carried through to the large intestine where microbial transformation may occur. This study aims to assess the gastrointestinal stability of the trichothecenes HT-2 toxin (HT-2), HT-2-ß-glucoside (HT-2-Glc), diacetoxyscirpenol (DAS), DAS-α-glucoside (DAS-Glc) and fumonisin B1 (FB1), N-(1-deoxy-d-fructos-1-yl) fumonisin-B1 (NDF-FB1). All tested modified mycotoxins were stable under upper gastrointestinal (GI) conditions. In faecal batch culture experiments, HT-2-Glc was hydrolysed efficiently and no further microbial biotransformation of HT-2 was observed. DAS-Glc hydrolysis was slow and DAS was de-acetylated to 15-monoacetoxyscripenol. NDF-FB1 was hydrolysed at the slowest rate and FB1 accumulation varied between donor samples. Our results demonstrate that all tested modified mycotoxins are stable in the upper GI tract and efficiently hydrolysed by human gut microbiota, thus potentially contributing to colonic toxicity. Hence the microbial biotransformation of any novel modified mycotoxins needs to be carefully evaluated.