Appropriateness to set a group health based guidance value for T2 and HT2 toxin and its modified forms

First Report on Mycotoxin Contamination of Hops (Humulus lupulus L.)

The presence of mycotoxins and other toxic metabolites in hops (Humulus lupulus L.) was assessed for the first time. In total, 62 hop samples were sampled in craft breweries, and analyzed by a multi-toxin LS-MS/MS method. The study collected samples from craft breweries in all of the Croatian counties and statistically compared the results. Based on previous reports on Alternaria spp. and Fusarium spp. contamination of hops, the study confirmed the contamination of hops with these toxins. Alternaria toxins, particularly tenuazonic acid, were found in all tested samples, while Fusarium toxins, including deoxynivalenol, were present in 98% of samples. However, no Aspergillus or Penicillium metabolites were detected, indicating proper storage conditions. In addition to the Alternaria and Fusarium toxins, abscisic acid, a drought stress indicator in hops, was also detected, as well as several unspecific metabolites. The findings suggest the need for monitoring, risk assessment, and potential regulation of Alternaria and Fusarium toxins in hops to ensure the safety of hop usage in the brewing and pharmaceutical industries. Also, four local wild varieties were tested, with similar results to the commercial varieties for toxin contamination, but the statistically significant regional differences in toxin occurrence highlight the importance and need for targeted monitoring.

Frequent Dietary Multi-Mycotoxin Exposure in UK Children and Its Association with Dietary Intake

Mycotoxins are potent fungal toxins that frequently contaminate agricultural crops and foods. Mycotoxin exposure is frequently reported in humans, and children are known to be particularly at risk of exceeding safe levels of exposure. Urinary biomonitoring is used to assess overall dietary exposure to multiple mycotoxins. This study aims to quantify multi-mycotoxin exposure in UK children and to identify major food groups contributing to exposure. Four repeat urine samples were collected from 29 children (13 boys and 16 girls, aged 2.4-6.8 years), and food diaries were recorded to assess their exposure to eleven mycotoxins. Urine samples (n = 114) were hydrolysed with β-glucuronidase, enriched through immunoaffinity columns and analysed by LC-MS/MS for deoxynivalenol (DON), nivalenol (NIV), T-2/HT-2 toxins, zearalenone (ZEN), ochratoxin A (OTA) and aflatoxins. Food diaries were analysed using WinDiet software, and the daily intake of high-risk foods for mycotoxin contamination summarised. The most prevalent mycotoxins found in urine samples were DON (95.6% of all samples), OTA (88.6%), HT-2 toxin (53.5%), ZEN (48.2%) and NIV (26.3%). Intake of total cereal-based foods was strongly positively associated with urinary levels of DON and T-2/HT-2 and oat intake with urinary T-2/HT-2. Average daily mycotoxin excretion ranged from 12.10 µg/d (DON) to 0.03 µg/d (OTA), and co-exposure to three or more mycotoxins was found in 66% of samples. Comparing mycotoxin intake estimates to tolerable daily intakes (TDI) demonstrates frequent TDI exceedances (DON 34.2% of all samples, T-2/HT-2 14.9%, NIV 4.4% and ZEN 5.2%). OTA was frequently detected at low levels. When mean daily OTA intake was compared to the reference value for non-neoplastic lesions, the resulting Margin of Exposure (MoE) of 65 was narrow, indicating a health concern. In conclusion, this study demonstrates frequent exposure of UK children to multiple mycotoxins at levels high enough to pose a health concern if exposure is continuous.

Using Microfluidic Hepatic Spheroid Cultures to Assess Liver Toxicity of T-2 Mycotoxin

The Fusarium fungi is found in cereals and feedstuffs and may produce mycotoxins, which are secondary metabolites, such as the T-2 toxin (T-2). In this work, we explored the hepatotoxicity of T-2 using microfluidic 3D hepatic cultures. The objectives were: (i) exploring the benefits of microfluidic 3D cultures compared to conventional 3D cultures available commercially (Aggrewell plates), (ii) establishing 3D co-cultures of hepatic cells (HepG2) and stellate cells (LX2) and assessing T-2 exposure in this model, (iii) characterizing the induction of metabolizing enzymes, and (iv) evaluating inflammatory markers upon T-2 exposure in microfluidic hepatic cultures. Our results demonstrated that, in comparison to commercial (large-volume) 3D cultures, spheroids formed faster and were more functional in microfluidic devices. The viability and hepatic function decreased with increasing T-2 concentrations in both monoculture and co-cultures. The RT-PCR analysis revealed that exposure to T-2 upregulates the expression of multiple Phase I and Phase II hepatic enzymes. In addition, several pro- and anti-inflammatory proteins were increased in co-cultures after exposure to T-2.

From ribosome to ribotoxins: understanding the toxicity of deoxynivalenol and Shiga toxin, two food borne toxins

Ribosomes that synthesize proteins are among the most central and evolutionarily conserved organelles. Given the key role of proteins in cellular functions, prokaryotic and eukaryotic pathogens have evolved potent toxins to inhibit ribosomal functions and weaken their host. Many of these ribotoxin-producing pathogens are associated with food. For example, food can be contaminated with bacterial pathogens that produce the ribotoxin Shiga toxin, but also with the fungal ribotoxin deoxynivalenol. Shiga toxin cleaves ribosomal RNA, while deoxynivalenol binds to and inhibits the peptidyl transferase center. Despite their distinct modes of action, both groups of ribotoxins hinder protein translation, but also trigger other comparable toxic effects, which depend or not on the activation of the ribotoxic stress response. Ribotoxic stress response-dependent effects include inflammation and apoptosis, whereas ribotoxic stress response-independent effects include endoplasmic reticulum stress, oxidative stress, and autophagy. For other effects, such as cell cycle arrest and cytoskeleton modulation, the involvement of the ribotoxic stress response is still controversial. Ribotoxins affect one organelle yet induce multiple toxic effects with multiple consequences for the cell. The ribosome can therefore be considered as the cellular "Achilles heel" targeted by food borne ribotoxins. Considering the high toxicity of ribotoxins, they pose a substantial health risk, as humans are highly susceptible to widespread exposure to these toxins through contaminated food sources.

Detection of T-2 Toxin in Wheat and Maize with a Portable Mass Spectrometer

T-2 toxin is a mycotoxin routinely found as a contaminant of cereal grains worldwide. A portable mass spectrometer was adapted to enable the detection of T-2 toxin in wheat and maize by APCI-MS. In order to facilitate rapid testing, a rapid cleanup was used. The method was able to detect T-2 toxin in soft white wheat, hard red wheat, and yellow dent maize and could be used to screen for T-2 at levels above 0.2 mg/kg. The HT-2 toxin was only detectable at very high levels (>0.9 mg/kg). Based on these results, the sensitivity was not sufficient to allow the application of the screening method to these commodities at levels recommended by the European Commission. With a cut-off level of 0.107 mg/kg, the method correctly classified nine of ten reference samples of wheat and maize. The results suggest that portable MS detection of T-2 toxin is feasible. However, additional research will be needed to develop an application sensitive enough to meet regulatory requirements.

Mitochondrial Damage Induced by T-2 Mycotoxin on Human Skin-Fibroblast Hs68 Cell Line

T-2 toxin is produced by different Fusarium species and belongs to the group of type A trichothecene mycotoxins. T-2 toxin contaminates various grains, such as wheat, barley, maize, or rice, thus posing a risk to human and animal health. The toxin has toxicological effects on human and animal digestive, immune, nervous and reproductive systems. In addition, the most significant toxic effect can be observed on the skin. This in vitro study focused on T-2 toxicity on human skin fibroblast Hs68 cell line mitochondria. In the first step of this study, T-2 toxin's effect on the cell mitochondrial membrane potential (MMP) was determined. The cells were exposed to T-2 toxin, which resulted in dose- and time-dependent changes and a decrease in MMP. The obtained results revealed that the changes of intracellular reactive oxygen species (ROS) in the Hs68 cells were not affected by T-2 toxin. A further mitochondrial genome analysis showed that T-2 toxin in a dose- and time-dependent manner decreased the number of mitochondrial DNA (mtDNA) copies in cells. In addition, T-2 toxin genotoxicity causing mtDNA damage was evaluated. It was found that incubation of Hs68 cells in the presence of T-2 toxin, in a dose- and time-dependent manner, increased the level of mtDNA damage in both tested mtDNA regions: NADH dehydrogenase subunit 1 (ND1) and NADH dehydrogenase subunit 5 (ND5). In conclusion, the results of the in vitro study revealed that T-2 toxin shows adverse effects on Hs68 cell mitochondria. T-2 toxin induces mitochondrial dysfunction and mtDNA damage, which may cause the disruption of adenosine triphosphate (ATP) synthesis and, in consequence, cell death.

Risk Assessment of Combined Exposure to Multiple Chemicals at the European Food Safety Authority: Principles, Guidance Documents, Applications and Future Challenges

Human health and animal health risk assessment of combined exposure to multiple chemicals use the same steps as single-substance risk assessment, namely problem formulation, exposure assessment, hazard assessment and risk characterisation. The main unique feature of combined RA is the assessment of combined exposure, toxicity and risk. Recently, the Scientific Committee of the European Food Safety Authority (EFSA) published two relevant guidance documents. The first one "Harmonised methodologies for the human health, animal health and ecological risk assessment of combined exposure to multiple chemicals" provides principles and explores methodologies for all steps of risk assessment together with a reporting table. This guidance supports also the default assumption that dose addition is applied for combined toxicity of the chemicals unless evidence for response addition or interactions (antagonism or synergism) is available. The second guidance document provides an account of the scientific criteria to group chemicals in assessment groups using hazard-driven criteria and prioritisation methods, i.e., exposure-driven and risk-based approaches. This manuscript describes such principles, provides a brief description of EFSA's guidance documents, examples of applications in the human health and animal health area and concludes with a discussion on future challenges in this field.

Human biomonitoring of multiple mycotoxins in hair: first large-scale pilot study

Human biomonitoring (HBM) represents the most accurate approach for assessing the exposure to mycotoxins, but traditional matrices fail to provide information about long-term exposure due to the rapid excretion rates and short half-lives of mycotoxins. Hair emerges as a promising matrix considering that contaminants can form stable links with hair components, such as keratins and melanin. Hence, the aim of the present study was to monitor the presence of up to ten mycotoxins (aflatoxins and Fusarium mycotoxins) in human hair samples (n=100) through a high-performance liquid chromatography coupled to Q-TOF high resolution mass spectrometry. A prevalence of 43% at concentrations ranging from 2.7 to 106.1 ng/g was observed, being enniatins and aflatoxin B1 the most prevalent compounds. Co-occurrence of up to three mycotoxins was observed in 42% of the positive samples. Retrospective untargeted analysis of hair samples tentatively identified up to 128 mycotoxins and related metabolites. These results confirm the accumulation of toxicologically relevant mycotoxins in hair matrix, thus standing as a suitable matrix for assessing long-term exposure.

T-2 Toxin Induces Ferroptosis by Increasing Lipid Reactive Oxygen Species (ROS) and Downregulating Solute Carrier Family 7 Member 11 (SLC7A11)

T-2 toxin is a trichothecene mycotoxin commonly found in animal feed and agricultural products. Evidence indicates that T-2 toxin induces apoptosis and autophagy. This study investigated the role of ferroptosis in T-2 toxin cytotoxicity. RAS-selective lethal compound 3 (RSL3) and Erastin were applied to initiate ferroptosis. RSL3- and Erastin-initiated cell death were enhanced by T-2 toxin. Treatment with the ferroptosis inhibitor ferrostatin-1 markedly restored the sensitizing effect of T-2 toxin to RSL3- or Erastin-initiated apoptosis, suggesting that ferroptosis plays a vital role in T-2 toxin-induced cytotoxicity. Mechanistically, T-2 toxin promoted ferroptosis by inducing lipid reactive oxygen species (ROS), as N-acetyl-l-cysteine significantly blocked T-2 toxin-induced ferroptosis. Moreover, T-2 toxin decreased the expression of solute carrier family 7 member 11 (SLC7A11) and failed to further enhance ferroptosis in SLC7A11-deficient cells. SLC7A11 overexpression significantly rescued the enhanced ferroptosis caused by T-2 toxin. T-2 toxin induces ferroptosis by downregulating SLC7A11 expression. Ferroptosis mediates T-2 toxin-induced cytotoxicity by increasing ROS and downregulating SLC7A11 expression.

Agronomic Factors Influencing the Scale of Fusarium Mycotoxin Contamination of Oats

Seven agronomic factors (crop season, farming system, harvest date, moisture, county, oat variety, and previous crop) were recorded for 202 oat crops grown across Ireland, and samples were analysed by LC-MS/MS for four major Fusarium mycotoxins: deoxynivalenol (DON), zearalenone (ZEN), T-2 toxin and HT-2 toxin. Type A trichothecenes were present in 62% of crops, with 7.4% exceeding European regulatory limits. DON (6.4%) and ZEN (9.9%) occurrences were relatively infrequent, though one and three samples were measured over their set limits, respectively. Overall, the type of farming system and the previous crop were the main factors identified as significantly influencing mycotoxin prevalence or concentration. Particularly, the adherence to an organic farming system and growing oats after a previous crop of grass were found to decrease contamination by type A trichothecenes. These are important findings and may provide valuable insights for many other types of cereal crops as Europe moves towards a much greater organic-based food system.

Updated Review of the Toxicity of Selected Fusarium Toxins and Their Modified Forms

Mycotoxins are one of the most dangerous food and feed contaminants, hence they have significant influence on human and animal health. This study reviews the information reported over the last few years on the toxic effects of the most relevant and studied Fusarium toxins and their modified forms. Deoxynivalenol (DON) and its metabolites can induce intracellular oxidative stress, resulting in DNA damage. Recent studies have also revealed the capability of DON and its metabolites to disturb the cell cycle and alter amino acid expression. Several studies have attempted to explore the mechanism of action of T-2 and HT-2 toxins in anorexia induction. Among other findings, two neurotransmitters associated with this process have been identified, namely substance P and serotonin (5-hydroxytryptamine). For zearalenone (ZEN) and its metabolites, the literature points out that, in addition to their generally acknowledged estrogenic and oxidative potentials, they can also modify DNA by altering methylation patterns and histone acetylation. The ability of the compounds to induce alterations in the expression of major metabolic genes suggests that these compounds can contribute to the development of numerous metabolic diseases, including type 2 diabetes.

Overall Exposure of European Adult Population to Mycotoxins by Statistically Modelled Biomonitoring Data

This study presents the exposure scenario to mycotoxins of adult population throughout Europe. The urinary biomarkers values were obtained by modelling data from two European projects. Exposure to AFB1, OTA, CIT, FBs, DON, NIV and T2/HT2 are presented. The main output obtained refers to a concern for public health about AFM1, FBs, T2/HT2 and NIV, and low concern for OTA, DON and CIT. The margin of exposure for AFM1 did not respect the reference value of 10,000 considered of low priority for risk; for Fusarium toxins, FBs and T2/HT2, probable daily intake (PDI) values resulted about ten times higher than their tolerable daily intake and NIV presented the most critical situation with a calculated PDI 30 times higher than the reference TDI value. North and South Europe scenarios were also depicted by clustering biomonitoring data. OTA and DON showed to be prevalent in Northern countries and the opposite was noticed for ZEN, higher in Southern countries. The critical issues of the availability of records feeding the dataset and of the accuracy of excretion rate for some mycotoxins are source of uncertainty for the reliability of the outputs, nevertheless the time is ripe for asking for more concrete HBM values and/or HBM-HBGV which would help in interpreting the burden of mycotoxins in Europe.

Mycotoxins in Pistachios (Pistacia vera L.): Methods for Determination, Occurrence, Decontamination

The consumption of pistachios (Pistacia vera L.) has been increasing, given their important benefit to human health. In addition to being an excellent nutritional source, they have been associated with chemical hazards, such as mycotoxins, resulting in fungal contamination and its secondary metabolism. Aflatoxins (AFs) are the most common mycotoxins in pistachio and the most toxic to humans, with hepatotoxic effects. More mycotoxins such as ochratoxin A (OTA), fumonisins (FBs), zearalenone (ZEA) and trichothecenes (T2, HT2 and DON) and emerging mycotoxins have been involved in nuts. Because of the low levels of concentration and the complexity of the matrix, the determination techniques must be very sensitive. The present paper carries out an extensive review of the state of the art of the determination of mycotoxins in pistachios, concerning the trends in analytical methodologies for their determination and the levels detected as a result of its contamination. Screening methods based on immunoassays are useful due to their simplicity and rapid response. Liquid chromatography (LC) is the gold standard with new improvements to enhance accuracy, precision and sensitivity and a lower detection limit. The reduction of Aspergillus' and aflatoxins' contamination is important to minimize the public health risks. While prevention, mostly in pre-harvest, is the most effective and preferable measure to avoid mycotoxin contamination, there is an increased number of decontamination processes which will also be addressed in this review.

The Influence of Zearalenone on Selected Hemostatic Parameters in Sexually Immature Gilts

Vascular toxicity induced by xenobiotics is associated with dysfunctions or damage to endothelial cells, changes in vascular permeability or dysregulation of the vascular redox state. The aim of this study was to determine whether per os administration of zearalenone (ZEN) influences selected hemostatic parameters in prepubertal gilts. This study was performed on female gilts divided into a control group which received placebo and an experimental group which received ZEN at a dose of 5.0 µg·kg-1 b.w. × day-1. On days 14, 28 and 42, blood samples were collected from the animals for analyses of hematological, coagulation and fibrinolysis parameters, nitric oxide, von Willebrand factor antigen content and catalase activity. The results demonstrated that the treatment of gilts with ZEN at a dose below no observable adverse effect level did not affect the primary hemostasis and the blood coagulation cascade. However, ZEN could have temporarily affected the selected indicators of endothelial cell function (increase of von Willebrand factor, decrease of nitric oxide levels) and the oxidative status plasma (decrease of catalase activity) of the exposed gilts. In summary, these results suggest that the adaptive response to ZEN-exposure can induce a transient imbalance in the vascular system by acting on vascular endothelial cells.

Evaluation of Mycotoxins in Infant Breast Milk and Infant Food, Reviewing the Literature Data

In this review, an analysis focusing on mycotoxin determination in infant breast milk and infant food has been summarised for the last fifteen years of research focused on the intended population group of 1-9 months. The objective was to know the level of exposure of the child population to an estimated daily intake (EDI) of mycotoxins from the consumption of habitual foods. The EDI was compared with the tolerable daily intake (TDI) established by EFSA to estimate risk. In breast milk, the high prevalence and levels were for samples from Africa (Egypt and Tanzania) with aflatoxin M1 (1.9 μg/L and 10%), and Asia (Iran) with ochratoxin-A (7.3 μg/L and 100%). In infant formulas, high incidences and values were for samples with aflatoxin M1 from Burkina Faso (167 samples, 84%, 87 μg/kg). In cereal products, the highest incidence was for DON from the United States (96 samples), and the highest value was an Italian sample (0.83 μg/kg of enniatin B). In fruit products, patulin was the most detected in Italian (78) and Spanish (24) samples. The highest risk was observed in breast milk during the first month of age, the highest EDI for aflatoxin M1 was reported for Egypt (344-595 ng/kg bw/day) and ochratoxin-A for Iran (97-167ng/kg bw/day), representing a public health problem.

Dietary exposure to mycotoxins of 1- and 2-year-old children from a Dutch Total Diet Study

In 2017, a Total Diet Study was conducted in the Netherlands in which mycotoxins were analysed in foods and beverages consumed by 1- and 2-year-old children. These mycotoxins were aflatoxins, Alternaria toxins, citrinin, ergot alkaloids, fumonisins, ochratoxin A, patulin, sterigmatocystin, trichothecenes, and zearalenone. Long-term exposure was calculated by combining concentrations in foods and beverages with consumed amounts of these products. Analysed foods and beverages with a concentration below the detection limit that could contain the mycotoxin, were assigned a concentration equal to half this limit value. To assess if the exposure could result in a possible health risk, the high long-term exposure (95th percentile) was compared with a health-based guidance value (HBGV) or a margin of exposure (MOE) was calculated. Exposure to aflatoxins, Alternaria toxins, ochratoxin A and T-2/HT-2 sum may pose a health concern. Foods that contributed most to the exposure of these mycotoxins were bread, biscuits, breakfast cereals, chocolates, dried fruit, follow-on formula and fruit juices.

Controlled Production of Zearalenone-Glucopyranoside Standards with Cunninghamella Strains Using Sulphate-Depleted Media

In recent years, conjugated mycotoxins have gained increasing interest in food safety, as their hydrolysis in human and animal intestines leads to an increase in toxicity. For the production of zearalenone (ZEN) glycosides reference standards, we applied Cunninghamellaelegans and Cunninghamella echinulata fungal strains. A sulphate-depleted medium was designed for the preferred production of ZEN glycosides. Both Cunninghamella strains were able to produce zearalenone-14-β-D-glucopyranoside (Z14G), zearalenone-16-β-D-glucopyranoside (Z16G) and zearalenone-14-sulphate (Z14S). In a rich medium, Cunninghamellaelegans preferably produced Z14S, while Cunninghamellaechinulata preferably produced Z14G. In the sulphate-depleted medium a dramatic change was observed for Cunninghamellaelegans, showing preferred production of Z14G and Z16G. From 2 mg of ZEN in sulphate-depleted medium, 1.94 mg of Z14G and 0.45 mg of Z16G were produced. Following preparative Liquid Chromatography-Mass Spectrometry (LC-MS) purification, both fractions were submitted to 1H and 13C NMR and High-Resolution Mass Spectrometry (HRMS). These analyses confirmed that the purified fractions were indeed Z14G and Z16G. In conclusion, the presented research shows that a single Cunninghamella strain can be an effective and efficient tool for the controlled biotransformation of ZEN glycosides and other ZEN metabolites. Additionally, the biotransformation method was extended to zearalanone, β-zearalenol and other mycotoxins.

Effects of a Low Dose of T-2 Toxin on the Percentage of T and B Lymphocytes and Cytokine Secretion in the Porcine Ileal Wall

Plant materials used in the production of pig feed are frequently contaminated with mycotoxins. T-2 toxin is a secondary metabolite of selected Fusarium species, and it can exert a harmful influence on living organisms. Most mycotoxins enter the body via the gastrointestinal tract, and they can modulate the gut-associated lymphoid tissue (GALT) function. However, little is known about the influence of low T-2 toxin doses on GALT. Therefore, the aim of this study was to evaluate the effect of T-2 toxin administered at 50% of the lowest-observed-adverse-effect level (LOAEL) on the percentage of CD2+ T cells, CD4+ T helper cells, CD8+ cytotoxic T cells, CD4+CD8+ double-positive T cells, TCRγδ+ cells, CD5+CD8- B1 cells, and CD21+ B2 cells, and the secretion of proinflammatory (IFN-γ, IL-1β, IL-2, IL-12/23p40, IL-17A), anti-inflammatory, and regulatory (IL-4, IL-10, TGF-β) cytokines in the porcine ileal wall. The results of the study revealed that T-2 toxin disrupts the development of tolerance to food antigens by enhancing the secretion of proinflammatory and regulatory cytokines and decreasing the production of anti-inflammatory TGF-β. T-2 toxin triggered the cellular response, which was manifested by an increase in the percentage of CD8+ T cells and a decrease in the percentage of B2 and Tγδ lymphocytes.

QuEChERS LC-MS/MS Screening Method for Mycotoxin Detection in Cereal Products and Spices

We developed and validated a screening method for mycotoxin analysis in cereal products and spices. Ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) was used for the analysis. Dispersive solid-phase extractions (d-SPEs) were used for the extraction of samples. Ochratoxin A (OTA), zearalenone (ZEA), aflatoxins (AFLA; AFB1, AFB2, AFG1, AFG2), deoxynivalenol (DON), fumonisin (FUMO; FB1, FB2, FB3), T2, and HT2 were validated in maize. AFLA and DON were validated in black pepper. The method satisfies the requirements of Commission Regulation (EC) no. 401/2006 and (EC) no. 1881/2006. The screening target concentration (STC) was under maximum permitted levels (MLs) for all mycotoxins validated. The method's performance was assessed by two different proficiencies and tested with 100 real samples.

Fusarium Head Blight From a Microbiome Perspective

The fungal genus Fusarium causes several diseases in cereals, including Fusarium head blight (FHB). A number of Fusarium species are involved in disease development and mycotoxin contamination. Lately, the importance of interactions between plant pathogens and the plant microbiome has been increasingly recognized. In this review, we address the significance of the cereal microbiome for the development of Fusarium-related diseases. Fusarium fungi may interact with the host microbiome at multiple stages during their life cycles and in different plant organs including roots, stems, leaves, heads, and crop residues. There are interactions between Fusarium and other fungi and bacteria as well as among Fusarium species. Recent studies have provided a map of the cereal microbiome and revealed how different biotic and abiotic factors drive microbiome assembly. This review synthesizes the current understanding of the cereal microbiome and the implications for Fusarium infection, FHB development, disease control, and mycotoxin contamination. Although annual and regional variations in predominant species are significant, much research has focused on Fusarium graminearum. Surveying the total Fusarium community in environmental samples is now facilitated with novel metabarcoding methods. Further, infection with multiple Fusarium species has been shown to affect disease severity and mycotoxin contamination. A better mechanistic understanding of such multiple infections is necessary to be able to predict the outcome in terms of disease development and mycotoxin production. The knowledge on the composition of the cereal microbiome under different environmental and agricultural conditions is growing. Future studies are needed to clearly link microbiome structure to Fusarium suppression in order to develop novel disease management strategies for example based on conservation biological control approaches.

Drinking Green Tea: Despite the Risks Due to Mycotoxins, Is It Possible to Increase the Associated Health Benefits?

Tea has been consumed for thousands of years. Despite the different varieties, particular emphasis has been placed on green tea (GT), considering the associated health benefits following its regular consumption, some of which are due to its polyphenol constituents, such as epigallocatechin-3-gallate (EGCG). Tea is not prone to the growth of microorganisms, except fungus, when proper storage, handling, and packing conditions are compromised. Consequently, mycotoxins, secondary metabolites of fungi, could contaminate tea samples, affecting human health. In the present study, we aimed to assess the balance between risks (due to mycotoxins and high levels of EGCG) and benefits (due to moderate intake of EGCG) associated with the consumption of GT. For this, 20 GT samples (10 in bulk and 10 in bags) available in different markets in Lisbon were analyzed through a LC-MS/MS method, evaluating 38 different mycotoxins. Six samples revealed detectable values of the considered toxins. Current levels of mycotoxins and EGCG intake were not associated with health concerns. Scenarios considering an increasing consumption of GT in Portugal showed that drinking up to seven cups of GT per day should maximize the associated health benefits. The present study contributes to the future establishment of GT consumption recommendations in Portugal.

The fate of mycotoxins during secondary food processing of maize for human consumption

Mycotoxins are naturally occurring fungal metabolites that are associated with health hazards and are widespread in cereals including maize. The most common mycotoxins in maize that occur at relatively high levels are fumonisins (FBs), zearalenone, and aflatoxins; furthermore, other mycotoxins such as deoxynivalenol and ochratoxin A are frequently present in maize. For these toxins, maximum levels are laid down in the European Union (EU) for maize raw materials and maize-based foods. The current review article gives a comprehensive overview on the different mycotoxins (including mycotoxins not regulated by EU law) and their fate during secondary processing of maize, based on the data published in the scientific literature. Furthermore, potential compliance with the EU maximum levels is discussed where appropriate. In general, secondary processing can impact mycotoxins in various ways. Besides changes in mycotoxin levels due to fractionation, dilution, and/or concentration, mycotoxins can be affected in their chemical structure (causing degradation or modification) or be released from or bound to matrix components. In the current review, a special focus is set on the effect on mycotoxins caused by different heat treatments, namely, baking, roasting, frying, (pressure) cooking, and extrusion cooking. Production processes involving multiple heat treatments are exemplified with the cornflakes production. For that, potential compliance with FB maximum levels was assessed. Moreover, effects of fermentation of maize matrices and production of maize germ oil are covered by this review.

Occurrence and Exposure Assessment of Mycotoxins in Ready-to-Eat Tree Nut Products through Ultra-High Performance Liquid Chromatography Coupled with High Resolution Q-Orbitrap Mass Spectrometry

Tree nuts have become popular snacks due to their attributed benefits in the health state. Nevertheless, their susceptibility to fungal contamination lead to the occurrence of potentially dangerous mycotoxins. Hence, the aim of this work was to evaluate the presence of mycotoxins in ready-to-eat almonds, walnuts, and pistachios from Italian markets. The most relevant mycotoxin found in almonds was α-zearalanol in 18% of samples (n = 17) ranging from 3.70 to 4.54 µg/kg. Walnut samples showed frequent contamination with alternariol, present in 53% of samples (n = 22) at levels from 0.29 to 1.65 µg/kg. Pistachios (n = 15) were the most contaminated commodity, with β-zearalenol as the most prevalent toxin present in 59% of samples ranging from 0.96 to 8.60 µg/kg. In the worst-case scenario, the exposure to zearalenone-derived forms accounted for 15.6% of the tolerable daily intake, whereas it meant 12.4% and 21.2% of the threshold of toxicological concern for alternariol and alternariol monomethyl-ether, respectively. The results highlighted the extensive presence of Alternaria toxins and zearalenone-derived forms, scarcely studied in ready-to-eat tree nut products, highlighting the necessity to include these mycotoxins in analytical methods to perform more realistic risk assessments.

Intestinal Metabolism of α- and β-Glucosylated Modified Mycotoxins T-2 and HT-2 Toxin in the Pig Cecum Model

The type A trichothecene mycotoxins T-2 and HT-2 toxin are fungal secondary metabolites produced by Fusarium fungi, which contaminate food and feed worldwide. Especially as a result of the high toxicity of T-2 toxin and their occurrence together with glucosylated forms in cereal crops, these mycotoxins are of human health concern. Particularly, it is unknown whether and how these modified mycotoxins are metabolized in the gastrointestinal tract and, thus, contribute to the overall toxicity. Therefore, the comparative intestinal metabolism of T-2 and HT-2 toxin glucosides in α and β configuration was investigated using the ex vivo pig cecum model, which mimics the human intestinal metabolism. Regardless of its configuration, the C-3 glycosidic bond was hydrolyzed within 10-20 min, releasing T-2 and HT-2 toxin, which were further metabolized to HT-2 toxin and T-2 triol, respectively. We conclude that T-2 and HT-2 toxin should be evaluated together with their modified forms for risk assessment.

Matrix binding of T-2 toxin: structure elucidation of reaction products and indications on the fate of a relevant food-borne toxin during heating

This study deals with the influence of food matrix components on the degradation of the mycotoxins T-2 toxin (T-2) and HT-2 toxin (HT-2) and with the binding of T-2 to starch during thermal food processing. Both mycotoxins were heated in a simulated food environment and subsequently analyzed via HPLC-HRMS to generate degradation curves and to draw conclusions regarding the thermal degradation under food processing conditions. Thermal degradation increased generally with increasing time and temperature with a maximum degradation rate of 93% (T-2) and 99% (HT-2). Furthermore, HRMS data were exploited to screen the samples for degradation products. In model heating experiments, T-2 was bound to 1-O-methyl-α-D-glucopyranoside, a model compound that was used to simulate starch. The formed reaction products were isolated and identified by NMR, giving detailed insights into a potential binding of T-2 to starch. In the next step, further model heating experiments were performed, which proved the covalent binding of T-2 to starch. Finally, the amount of matrix-bound T-2 was estimated roughly in a semi-quantitative approach in the model heating experiments as well as during cookie-making via GC-MS analysis of the isovaleric acid ester moiety of T-2, released after alkaline hydrolysis.

Glucosylation of T-2 and HT-2 toxins using biotransformation and chemical synthesis: Preparation, stereochemistry, and stability

Plant-derived phase II metabolites of T-2 toxin (T2) and HT-2 toxin (HT2) were first described in 2011 and further characterized in the following years. Since then, some efforts have been made to understand their biosynthesis, occurrence, toxicity, toxicokinetics, and finally relevance for consumers. Thus, the probably most important question is whether and how these metabolites contribute to toxicity upon hydrolysis either during food processing or the gastrointestinal passage. To answer this question, firstly, knowledge on the correct stereochemistry of T2 and HT2 glucosides is important as this affects hydrolysis and chemical behavior. So far, contradictory results have been published concerning the number and anomericity of occurring glucosides. For this reason, we set up different strategies for the synthesis of mg-amounts of T2, HT2, and T2 triol glucosides in both α and ß configuration. All synthesized glucosides were fully characterized by NMR spectroscopy as well as mass spectrometry and used as references for the analysis of naturally contaminated food samples to validate or invalidate their natural occurrence. Generally, 3-O-glucosylation was observed with two anomers of HT2 glucoside being present in contaminated oats. In contrast, only one anomer of T2 glucoside was found. The second aspect of this study addresses the stability of the glucosides during thermal food processing. Oat flour was artificially contaminated with T2 and HT2 glucosides individually and extruded at varying initial moisture content and temperature. All four glucosides appear to be more stable during food extrusion than the parent compounds with the glucosidic bond not being hydrolyzed.

Metabolic profile of the masked mycotoxin T-2 toxin-3-glucoside in rats (in vitro and in vivo) and humans (in vitro)

The metabolic profile of T-2 toxin-3-glucoside (T2-Glc) in humans and rats was investigated using ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF). When rat and human liver microsomes were incubated with T2-Glc, a total of five metabolites were detected. T2-Glc exposed a higher metabolic stability in rats and human than T-2 toxin (T-2). The metabolism of T2-Glc by the intestinal microbiota of human and rats was also investigated, and three metabolites were observed. T2-Glc was reconverted to T-2 during incubation with fresh faeces. Furthermore, in vivo metabolism of T2-Glc in rats after oral administration was carried out, and three metabolites were detected in rat urine and faeces (T-2, HT-2 toxin and 3'-OH-T2-Glc). In vivo metabolism results indicated that T2-Glc was mainly metabolised in the gastro-intestinal tract with a low absorption level in rats. The results demonstrated that hydroxylation (C-3' and C-4'), hydrolysis (C-4 and C-8) and deconjugation are the main metabolic pathways of T2-Glc in mammals.

Analysis of the Masked Metabolite of Deoxynivalenol and Fusarium Resistance in CIMMYT Wheat Germplasm

Fusarium head blight (FHB) causes significant grain loss and contamination of grains with harmful mycotoxins, especially deoxynivalenol (DON). Fusarium resistance and DON accumulation have been extensively investigated in various cultivars; however, the level of DON-3-O-glucoside (D3G) has not been as carefully studied. In this study, we measured accumulated DON and D3G levels in CIMMYT wheat elite germplasm using an analytical method validated in-house. Co-occurring nivalenol (NIV) and ergostrerol (ERG) were also analyzed. LC-MS/MS and LC-UV analyses were applied to the 50 CIMMYT elite wheat lines. D3G showed rather high correlation with DON (r = 0.82), while FHB symptoms showed slight correlation with DON and D3G (r = 0.36 and 0.32, respectively). D3G/DON ratio varied widely from 8.1 to 37.7%, and the ratio was not related with FHB resistance in this dataset.

Appropriateness to set a group health based guidance value for nivalenol and its modified forms

The EFSA Panel on Contaminants in the Food Chain (CONTAM) reviewed new studies on nivalenol since the previous opinion on nivalenol published in 2013, but as no new relevant data were identified the tolerable daily intake (TDI) for nivalenol (NIV) of 1.2 μg/kg body weight (bw) established on bases of immuno- and haematotoxicity in rats was retained. An acute reference dose (ARfD) of 14 μg/kg bw was established based on acute emetic events in mink. The only phase I metabolite of NIV identified is de-epoxy-nivalenol (DE-NIV) and the only phase II metabolite is nivalenol-3-glucoside (NIV3Glc). DE-NIV is devoid of toxic activity and was thus not further considered. NIV3Glc can occur in cereals amounting up to about 50% of NIV. There are no toxicity data on NIV3Glc, but as it can be assumed that it is hydrolysed to NIV in the intestinal tract it should be included in a group TDI and in a group ARfD with NIV. The uncertainty associated with the present assessment is considered as high and it would rather overestimate than underestimate any risk.