Marthe De Boevre

Human exposure to mycotoxins and their masked forms through cereal-based foods in Belgium

In the present study, a quantitative dietary exposure assessment of mycotoxins and their masked forms was conducted on a national representative sample of the Belgian population using the contamination data of cereal-based foods. Cereal-based food products (n=174) were analysed for the occurrence of deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, zearalenone, α-zearalenol, β-zearalenol, T-2-toxin, HT-2-toxin, and their respective masked forms, including, deoxynivalenol-3-glucoside, zearalenone-4-glucoside, α-zearalenol-4-glucoside, β-zearalenol-4-glucoside and zearalenone-4-sulfate. Fibre-enriched bread, bran-enriched bread, breakfast cereals, popcorn and oatmeal were collected in Belgian supermarkets according to a structured sampling plan and analysed during the period from April 2010 to October 2011. The habitual intake of these food groups was estimated from a national representative food intake survey. According to a probabilistic exposure analysis, the mean (and P95) mycotoxin intake for the sum of the deoxynivalenol-equivalents, zearalenone-equivalents, and the sum of HT-2-and T-2-toxin for all cereal-based foods was 0.1162 (0.4047, P95), 0.0447 (0.1568, P95) and 0.0258 (0.0924, P95) μg kg(-1)body weight day(-1), respectively. These values were below the tolerable daily intake (TDI) levels for deoxynivalenol, zearalenone and the sum of T-2 and HT-2 toxin (1.0, 0.25 and 0.1 μg kg(-1)body weight day(-1), respectively). The absolute level exceeding the TDI for all cereal-based foods was calculated, and recorded 0.85%, 2.75% and 4.11% of the Belgian population, respectively.

Dietary mycotoxins, co-exposure, and carcinogenesis in humans: Short review

Mycotoxins, toxic secondary metabolites of fungi, affect global agriculture so prolifically that they are virtually ubiquitous at some concentration in the average human diet. Studies of in vitro and in vivo toxicity are discussed, leading to investigations of co-exposed mycotoxins, as well as carcinogenic effects. Some of the most common and toxicologically significant mycotoxins, such as the aflatoxins, ochratoxins, fumonisins, deoxynivalenol, T-2 toxin, HT-2 toxin, patulin, zearalenone, and some ergot alkaloids are outlined. The wide variety of pathogenic mechanisms these compounds employ are shown capable of inducing a complex set of interactions. Of particular note are potential synergisms between mycotoxins with regard to carcinogenic attributable risk, indicating an important field for future study.

Metabolism of modified mycotoxins studied through in vitro and in vivo models: an overview.

Mycotoxins are toxic, secondary metabolites produced by fungi. They occur in a wide variety of food and feed commodities, and are of major public health concern because they are the most hazardous of all food and feed contaminants in terms of chronic toxicity. In the past decades, it has become clear that in mycotoxin-contaminated commodities, many structurally related compounds generated by plant metabolism, fungi or food processing coexist with their free mycotoxins, defined as modified mycotoxins. These modified xenobiotics might endanger animal and human health as they are possibly hydrolysed into their free toxins in the digestive tract of mammals, and may consequently contribute to an unexpected high toxicity. As modified toxins represent an emerging issue, it is not a surprise that for most toxicological tests data are scarce to non-existent. Therefore, there is a need to elucidate the disposition and kinetics of both free and modified mycotoxins in mammals to correctly interpret occurrence data and biomonitoring results. This review emphasizes the current knowledge on the metabolism of modified mycotoxins using in vitro and in vivo models.

The compositional mosaic of Fusarium species and their mycotoxins in unprocessed cereals, food and feed products in Belgium

Global food safety depends on continuous monitoring of food contaminants such as mycotoxins in cereals and cereal-derived products. Here, we combine this type of investigation with quantitative occurrence data on Fusarium infestation of these products in extensive correlation studies. Finally, this contributes to a thorough understanding of the presence, origin and physiology of Fusarium Head Blight (FHB) related mycotoxins and the correlations within their ranks. Two hundred and thirty-seven samples were analyzed from diverse cereal matrices, representing the most important stages of the cereal food and feed chain in Belgium. Food, feed and non-processed field samples were investigated, with a strong emphasis on whole-grain food products. Two approaches were pursued to estimate the full scope of FHB and its repercussions: UPLC-MS/MS was applied to detect twelve different mycotoxins, and Q-PCR was used to measure the presence of ten Fusarium species. We found that different matrices have different characteristic contamination profiles, and extensive correlation studies identified certain mycotoxins for future assessment (e.g. moniliformin produced by the Fusarium avenaceum/Fusarium tricinctum species group). The investigated harvest year of 2012 yielded many non-processed field materials containing elevated levels of deoxynivalenol (DON), while even in a so-called DON-year less prevalent toxins such as T-2 and HT-2 might be considered problematic due to their consistent co-occurrence with related mycotoxins. Our data illustrate complex interactions between the many Fusarium species that are responsible for FHB and their mycotoxins. Correlation studies demonstrate that consistent co-occurrence of mycotoxins is not to be neglected, and pinpoint issues for future surveillance and legislation.

Occurrence of Fusarium Mycotoxins in Cereal Crops and Processed Products (Ogi) from Nigeria

In Nigeria, maize, sorghum, and millet are very important cash crops. They are consumed on a daily basis in different processed forms in diverse cultural backgrounds. These crops are prone to fungi infestation, and subsequently may be contaminated with mycotoxins. A total of 363 samples comprising of maize (136), sorghum (110), millet (87), and ogi (30) were collected from randomly selected markets in four agro-ecological zones in Nigeria. Samples were assessed for Fusarium mycotoxins contamination using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Subsequently, some selected samples were analysed for the occurrence of hidden fumonisins. Overall, 64% of the samples were contaminated with at least one toxin, at the rate of 77%, 44%, 59%, and 97% for maize, sorghum, millet, and ogi, respectively. Fumonisins were the most dominant, especially in maize and ogi, occurring at the rate of 65% and 93% with mean values of 935 and 1128 μg/kg, respectively. The prevalence of diacetoxyscirpenol was observed in maize (13%), sorghum (18%), and millet (29%), irrespective of the agro-ecological zone. Other mycotoxins detected were deoxynivalenol, zearalenone, and their metabolites, nivalenol, fusarenon-X, HT-2 toxin, and hidden fumonisins. About 43% of the samples were contaminated with more than one toxin. This study suggests that consumption of cereals and cereal-based products, ogi particularly by infants may be a source of exposure to Fusarium mycotoxins.

The Status of Fusarium Mycotoxins in Sub-Saharan Africa: A Review of Emerging Trends and Post-Harvest Mitigation Strategies towards Food Control

Fusarium fungi are common plant pathogens causing several plant diseases. The presence of these molds in plants exposes crops to toxic secondary metabolites called Fusarium mycotoxins. The most studied Fusarium mycotoxins include fumonisins, zearalenone, and trichothecenes. Studies have highlighted the economic impact of mycotoxins produced by Fusarium. These arrays of toxins have been implicated as the causal agents of wide varieties of toxic health effects in humans and animals ranging from acute to chronic. Global surveillance of Fusarium mycotoxins has recorded significant progress in its control; however, little attention has been paid to Fusarium mycotoxins in sub-Saharan Africa, thus translating to limited occurrence data. In addition, legislative regulation is virtually non-existent. The emergence of modified Fusarium mycotoxins, which may contribute to additional toxic effects, worsens an already precarious situation. This review highlights the status of Fusarium mycotoxins in sub-Saharan Africa, the possible food processing mitigation strategies, as well as future perspectives.

In vitro and in vivo metabolism of ochratoxin A: a comparative study using ultra-performance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry

AbstractOchratoxin A (OTA) is a mycotoxin that frequently contaminates a wide variety of food and feedstuffs. The metabolism of OTA greatly affects fate and toxicity in humans and animals, because of its possible carcinogenic character (International Agency for Research on Cancer (IARC), group 2B). To completely characterize the metabolites of OTA, the metabolism of OTA in liver microsomes of rats, chickens, swine, goats, cows, and humans was investigated using ultra-performance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry (UPLC-Q/TOF-MS). In addition, an in vivo comparative metabolism study of OTA was performed among rats and chickens after oral administration of OTA. As a result, a clear metabolic profile of OTA in different species was proposed, and a total of eight metabolites were identified, of which three hydroxylated metabolites at the phenylalanine moiety were discovered for the first time (preliminarily identified as 9′-OH-OTA, 7′-OH-OTA, and 5′-OH-OTA). Considerable amounts of 7′-OH-OTA were detected in different species’ liver microsomes, especially in chickens and humans. Moreover, the metabolism of OTA in chickens was elucidated for the first time in the present study. The 7′-OH-OTA proved to be the main metabolite in vitro and in vivo in chickens. Furthermore, the 4(S)-OH-OTA isomer was the major one, and 4(R)-OH-OTA the minor metabolite in chickens, which was different from others where 4R was the major. OTA undergoes metabolism via three different pathways, namely hydroxylation, dechlorination, and conjugation. The proposed metabolic pathways of OTA in various species provide the scientific community useful data for the toxicological safety evaluation of OTA among different species, and will further facilitate the food safety evaluation of OTA. Graphical abstractIn Vitro and in Vivo Metabolism of Ochratoxin A: A Comparative Study Using Ultra-Performance Liquid Chromatography-Quadrupole/Time-of-Flight Hybrid Mass Spectrometry

Sampling of Wheat Dust and Subsequent Analysis of Deoxynivalenol by LC-MS/MS

An LC-MS/MS method was developed and validated for the determination of deoxynivalenol in wheat dust. Extraction was carried out with acetonitrile/water/acetic acid (79/20/1, v/v/v) followed by a hexane defatting step. Analysis was performed using a Waters Acquity UPLC system coupled to a Quattro Premier XE mass spectrometer. The method was validated according to the criteria mentioned in Commission Decision 2002/657/EC. Due to a high contamination level of wheat dust compared to wheat, limit of detection and limit of quantitation levels of 358 ng/g and 717 ng/g, respectively, were obtained. A small survey was executed on raw wheat materials and their corresponding dust samples (n = 12). The samples were analyzed according to the developed procedure. A linear correlation (R² = 0.941) was found for the deoxynivalenol concentration in dust versus the deoxynivalenol concentration in wheat. Therefore, it would be possible to estimate the cereal contamination through dust contamination.

Unraveling the in vitro and in vivo metabolism of diacetoxyscirpenol in various animal species and human using ultrahigh-performance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry.

AbstractDiacetoxyscirpenol (DAS), a Fusarium mycotoxin belonging to the trichothecene type A mycotoxins, is able to contaminate food and feed worldwide. Only limited information is available regarding the metabolism of DAS. The present study used ultrahigh-performance liquid chromatography-quadrupole/time-of-flight hybrid mass spectrometry (UHPLC-Q/TOF) to investigate the in vitro phase I and II metabolism of DAS by rat, chicken, swine, goat, cow, and human liver microsomes. An extensive metabolization profile of DAS has been observed. A total of seven phase I and three phase II metabolites of DAS were detected. Among the identified molecules, four phase I metabolites (8β-hydroxy-DAS, neosolaniol, 7-hydroxy-DAS, and its epimer) and two phase II metabolites (4-deacetyl-DAS-3-glucuronic acid and 4-deacetyl-DAS-4-glucuronic acid) were identified for the first time. These results indicate that the major metabolic pathways of DAS in vitro were hydrolyzation (M1–M3), hydroxylation (M4–M7), and conjugation (M8–M10). Qualitative differences in phase I and II metabolic profiles of DAS between the five animal species and human were observed. 4-Deacetyl-DAS was the primary metabolite from liver microsomes of all species, especially human. The in vivo metabolism of DAS in rats and chickens after oral administration of DAS was also investigated and compared. The major metabolites for rats and chickens were 4-deacetyl-DAS and 7-hydroxy-DAS. These results will help to gain a more detailed insight into the metabolism and toxicity of DAS among different animal species and human. Graphical AbstractThe metabolism of diacetoxyscirpenol in farm animals and human

Awareness and Prevalence of Mycotoxin Contamination in Selected Nigerian Fermented Foods

Fermented food samples (n = 191) including maize gruel (ogi), sorghum gruel (ogi-baba), melon seed (ogiri), locust bean (iru) and African oil bean seed (ugba) from Southwest Nigeria were quantified for 23 mycotoxins, including aflatoxin B1 (AFB1), fumonisin B1 (FB1), and sterigmatocystin (STE) using liquid chromatography-tandem mass spectrometry. The practices, perceived understanding and health risks related to fungal and mycotoxin contamination amongst fermented food sellers was also established. Data obtained revealed that 82% of the samples had mycotoxins occurring singly or in combination. FB1 was present in 83% of ogi-baba samples, whereas 20% of ugba samples contained AFB1 (range: 3 to 36 µg/kg) and STE was present in 29% of the ogi samples. In terms of multi-mycotoxin contamination, FB1 + FB2 + FB3 + STE + AFB1 + alternariol + HT-2 co-occurred within one sample. The awareness study revealed that 98% of respondents were unaware of mycotoxin contamination, and their education level slightly correlated with their level of awareness (p < 0.01, r = 0.308). The extent to which the analyzed mycotoxins contaminated these food commodities, coupled with the poor perception of the population under study on fungi and mycotoxins, justifies the need to enact fungal and mycotoxin mitigation strategies along the food chain.