Mycotoxins in wheat flour: occurrence and co-occurrence assessment in samples from Southern Brazil

Influence of regional and yearly weather patterns on multi-mycotoxin occurrence in Austrian wheat: a liquid chromatographic-tandem mass spectrometric and multivariate statistics approach

BACKGROUND

Mycotoxin surveys play an essential role in our food safety system. The obtained occurrence data form the basis for the assessment of the exposure of humans and animals to these toxic fungal secondary metabolites. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has become the gold standard for mycotoxin determination because it enables selective and sensitive multi-toxin analysis. Simultaneous determination of several hundreds of secondary fungal metabolites is feasible using this technique. In this study, we combined a targeted dilute-and-shoot LC-MS/MS-based multi-analyte approach with multivariate statistics for the analysis of Austrian wheat from two different years and different geographical origins.

RESULTS

We quantified 47 secondary fungal metabolites, including regulated emerging and masked mycotoxins. The resulting multi-mycotoxin occurrence data were further analyzed using both multivariate and univariate statistics. Principal component analysis (PCA) and analysis of variance (ANOVA) simultaneous component analysis (ASCA) were employed to identify regional and yearly trends within the dataset and to quantify the variance in metabolite occurrence attributed to the different effects. In addition, secondary fungal metabolites significantly impacted by these factors were selected via ANOVA. Of the 47 secondary metabolites identified, 39 were affected by the year, region or a combined effect. Moreover, our findings show that 43 of the secondary fungal metabolites were significantly influenced by the weather conditions.

CONCLUSION

The results presented in this study underline the added value of combining targeted LC-MS/MS with multivariate statistics for monitoring a broad spectrum of secondary fungal metabolites in food crops. Through multivariate statistics, trends associated with the year or region can be readily studied. The approach presented could pave the way for a better understanding of the impact of climate change on plant pathogenic fungi and its implications for food safety. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The fate of Alternaria toxin tenuazonic acid (TeA) during the processing chain of wheat flour products and risk control strategies for mycotoxins

The fate of Alternaria toxin tenuazonic acid (TeA) during the processing chain of wheat flour products was systemically evaluated. TeA was analyzed by liquid chromatography-mass spectrometry (LC-MS/MS) in wheat grains and the corresponding wheat flour products produced throughout the whole chain. The results indicated that TeA contamination in wheat grains largely determines the level of TeA toxin present in byproducts, semi-finished products, and finished products of the processing of four types of simulated processed wheat flour products (e.g., dry noodles, steamed breads, baked breads, and biscuits). The different food processing techniques had different effects on the fate of TeA. Wheat flour processing can reduce the TeA content in wheat grains by 58.7-83.2 %, indicating that wheat flour processing is a key step in reducing the TeA content in the food chain. Among the four types of wheat flour products, the decreases in TeA content in biscuits (69.8-76.7 %) were greater than those in dry noodles (15.5-22.3 %) and steamed breads (24.9-43.6 %). In addition, the decreasing effect of TeA was especially obvious in the wheat flour product chain with a high level of contamination. The processing factors (PFs) for TeA were as low as 0.20 for the four wheat processing methods and as high as 1.24 for the dry noodle processing method. At the average and 95th percentiles, dietary exposure to TeA in Chinese consumers including infants and young children did not exceed the relevant threshold value of toxicological concern (TTC) of TeA (1.5 µg/kg body weight per day), indicating an acceptable health risk for Chinese consumers via wheat flour products. These findings provide new insight into the fate of TeA in the food chain and mycotoxin control on the safety of wheat flour products and public health.

Negative Effects of Occurrence of Mycotoxins in Animal Feed and Biological Methods of Their Detoxification: A Review

Secondary metabolic products of molds, called mycotoxins, negatively affect animal health and production. They constitute a significant problem in veterinary and medical sciences, and their presence has been confirmed in feed all over the world. Applying appropriate agricultural practices and ensuring proper storage conditions significantly reduces the contamination of agricultural products with mycotoxins. However, this does not guarantee that raw materials are completely free from contamination. Many detoxification methods are currently used, but their insufficient effectiveness and negative impact on the quality of the raw material subjected to them significantly limits their usefulness. The positive results of eliminating mycotoxins from many products have been proven by the specific properties of microorganisms (bacteria, yeast, and fungi) and the enzymes they produce. Biological detoxification methods seem to offer the most promising opportunities to solve the problem of the presence of mycotoxins in animal food. This work, based on literature data, presents the health risks to farm animals consuming mycotoxins with feed and discusses the biological methods of their purification.

Co-contamination and interactions of multiple mycotoxins and heavy metals in rice, maize, soybeans, and wheat flour marketed in Shanghai City

Mycotoxins and heavy metals extensively contaminate grains and grain products, posing severe health risks. This work implements validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and inductively coupled plasma mass spectrometry (ICP-MS) methods to quantify the concentration of 12 mycotoxins and five heavy metals in rice, maize, soybeans, and wheat flour samples marketed in Shanghai. The mixed contamination characteristics were analyzed using correlation cluster analysis and co-contamination index, and the probabilities of all cross combinations of contaminations were analyzed using a self-designed JAVA language program. The results showed that grains and grain products were frequently contaminated with both mycotoxins and heavy metals, mostly with deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON), ochratoxin A (OTA), aflatoxins, fumonisin B1 (FB1), fumonisin B2 (FB2), fumonisin B3 (FB3), arsenic (As), chromium (Cr) and cadmium (Cd). All the samples (100 %) were contaminated with two or more contaminants, and 77.3 % of the samples were co-contaminated with more than four contaminants. In cereals and cereal products, the following combinations were closely associated: (FB3 +3-ADON), (FB1 +As), (FB1 +FB2), (DON+FB1), (DON+Cd), (As+Cd), (DON+Cd+As), (FB1 +FB2 +As), and (DON+3-ADON+15-ADON). The results indicated that mycotoxins and heavy metals frequently co-occurred in Shanghai grains and grain products, and they provided primary data for safety assessments, early warnings, and regulatory measures on these contaminants to protect public health.

Fungal and Toxin Contaminants in Cereal Grains and Flours: Systematic Review and Meta-Analysis

Cereal grains serve as the cornerstone of global nutrition, providing a significant portion of humanity's caloric requirements. However, the presence of fungal genera, such Fusarium, Penicillium, Aspergillus, and Alternaria, known for their mycotoxin-producing abilities, presents a significant threat to human health due to the adverse effects of these toxins. The primary objective of this study was to identify the predominant fungal contaminants in cereal grains utilized in breadmaking, as well as in flour and bread. Moreover, a systematic review, including meta-analysis, was conducted on the occurrence and levels of mycotoxins in wheat flour from the years 2013 to 2023. The genera most frequently reported were Fusarium, followed by Penicillium, Aspergillus, and Alternaria. Among the published reports, the majority focused on the analysis of Deoxynivalenol (DON), which garnered twice as many reports compared to those focusing on Aflatoxins, Zearalenone, and Ochratoxin A. The concentration of these toxins, in most cases determined by HPLC-MS/MS or HPLC coupled with a fluorescence detector (FLD), was occasionally observed to exceed the maximum limits established by national and/or international authorities. The prevalence of mycotoxins in flour samples from the European Union (EU) and China, as well as in foods intended for infants, exhibited a significant reduction compared to other commercial flours assessed by a meta-analysis investigation.

Integrated lncRNA transcriptomics, proteomics, and metabolomics to identify early cellular response variation in deoxynivalenol-treated IPEC-J2 cells

Mycotoxins, especially deoxynivalenol (DON), are common contaminants of food and feed, which also has serious threaten to human health and livestock production. Moreover, DON severely impair intestinal epithelial barrier function. Therefore, it is necessary to investigate the mechanism of intestinal epithelial cell injury induced by DON. Here, intestinal porcine enterocyte cell (IPEC-J2) was incubated with 200 ng/ml or 2000ng/ml DON for 6 h, then lncRNA sequencing, metabolomics and proteomics were applied. Combined with long coding transcriptomics, and proteomics, 200 ng/ml DON treatment (LDON group) significantly upregulated ribosome biogenesis in eukaryotes, spliceosome, and ubiquitin mediated proteolysis, RNA transport, and downregulated metabolic pathways in IPEC-J2, 2000 ng/ml of DON treatment (HDON group) significantly upregulated ribosome biogenesis in eukaryotes, and spliceosome, and downregulated base excision repair, cell cycle, DNA replication, homologous recombination, and mismatch repair in IPEC-J2. Combined with long coding transcriptomics, and proteomics, as compared with LDON group, HDON group significantly upregulated adherens junction, hippo signaling pathway, and pathways in cancer, and downregulated DNA replication pathways in IPEC-J2. In metabolomics, LDON group and HDON group was mainly downregulated biosynthesis of unsaturated fatty acids, and fatty acid metabolism. These results provide a new insight to prevent and treat DON induced intestinal epithelial cell injury.

Determination of Regulated and Emerging Mycotoxins in Organic and Conventional Gluten-Free Flours by LC-MS/MS

Gluten-free cereal products have grown in popularity in recent years as they are perceived as "healthier" alternatives and can be safely consumed by celiac patients, and people with gluten intolerance or wheat allergies. Molds that produce mycotoxins contaminate cereal crops, posing a threat to global food security. Maximum levels have been set for certain mycotoxins in cereal flours; however, little is known about the levels of emerging mycotoxins in these flours. The aim of this study was to develop an efficient, sensitive, and selective method for the detection of four emerging (beauvericin and enniatins A1, B, and B1) and three regulated (aflatoxin B1, zearalenone, and deoxynivalenol) mycotoxins in gluten-free flours. Ultrasound-assisted matrix solid-phase dispersion was used in the extraction of these mycotoxins from flour samples. The validated method was utilized for the LC-MS/MS analysis of conventional and organic wholegrain oat and rice flours. Six of the seven target mycotoxins were detected in these samples. Multi-mycotoxin contamination was found in all flour types, particularly in conventional wholegrain oat flour. Despite the low detection frequency in rice flour, one sample was found to contain zearalenone at a concentration of 83.2 μg/kg, which was higher than the level set by the European Commission for cereal flours. The emerging mycotoxins had the highest detection frequencies; enniatin B was present in 53% of the samples at a maximum concentration of 56 μg/kg, followed by enniatin B1 and beauvericin, which were detected in 46% of the samples, and at levels reaching 21 μg/kg and 10 μg/kg, respectively. These results highlight the need to improve the current knowledge and regulations on the presence of mycotoxins, particularly emerging ones, in gluten-free flours and cereal-based products.

Performance Evaluation of Biochip Chemiluminescent Immunoassay for Screening Seven Mycotoxins in Wheat Flour Simultaneously

Background

Wheat grains are susceptible to mycotoxins, toxic natural secondary metabolites generated by certain fungi on agricultural produce in the field during growth, harvest, transportation, or storage. Therefore, wheat flour can be contaminated with mycotoxins, which seriously threaten human health.

Methods

A rapid method for screening seven mycotoxins in wheat flour was validated in accordance with Commission Decision 2002/657/EC. With this multi-analytical screening method, 7 prevalent mycotoxins (fumonisin B1, ochratoxin A, aflatoxin G1, deoxynivalenol, T-2 toxin, aflatoxin B1, and zearalenone) can be determined simultaneously. The method's applicability was demonstrated by screening 7 mycotoxins in 39 wheat flour samples collected from different bakeries in Tehran province, Iran.

Results

The validation results indicated that for all 7 mycotoxins, the positivity threshold (T) was above the cut-off value (Fm), and no false positive results were obtained for any of the mycotoxins. The screening results of 12 packaged and 27 bulk wheat flour samples indicated that the concentrations of all mentioned mycotoxins were higher than the cut-off (in the relative light unit [RLU]), and all the samples were compliant.

Conclusions

The present study revealed that the biochip-based technique is valid for identifying and assessing the levels of 7 mycotoxins in grain samples, such as wheat flour, at the measured validation concentrations. The method was simple, fast, and able to screen 7 mycotoxins simultaneously. The test process of the kit is easy to conduct, and the results are straightforward to interpret.

Occurrence and Exposure Assessment of Deoxynivalenol and Its Acetylated Derivatives from Grains and Grain Products in Zhejiang Province, China (2017–2020)

Deoxynivalenol (DON) together with its acetylated derivatives cause detrimental effects on human health, and the purpose of this study was to assess the prevalence of DON and its acetylated derivatives from grains and grain products in Zhejiang province, China, and to assess the risk of DON and its acetylated derivatives due to multiple consumptions of grains and grain products among the Zhejiang population. Food samples numbering 713 were collected, and the LC-MS/MS method was used to determine the toxins. The levels of toxins from grains and grain products were relatively low: DON was the toxin at the highest levels. The food frequency questionnaire was used to collect food consumption data. The result of exposure assessments showed that the population was overall at low levels of toxin exposure. The probable mean group daily intake of toxins was 0.21 μg/kg bw/day, which was far from the group provisional maximum tolerable daily intake of 1 μg/kg bw/day, but 0.71% of participants were at high exposure levels. Rice and dried noodles (wheat-based food) were the main sources of toxin exposure, and reducing the consumption of rice and dried noodles while consuming more of other foods with lower levels of toxins is recommended.

The Fungal Microbiome of Wheat Flour Includes Potential Mycotoxin Producers

Consumers are increasingly demanding higher quality and safety standards for the products they consume, and one of this is wheat flour, the basis of a wide variety of processed products. This major component in the diet of many communities can be contaminated by microorganisms before the grain harvest, or during the grain storage right before processing. These microorganisms include several fungal species, many of which produce mycotoxins, secondary metabolites that can cause severe acute and chronic disorders. Yet, we still know little about the overall composition of fungal communities associated with wheat flour. In this study, we contribute to fill this gap by characterizing the fungal microbiome of different types of wheat flour using culture-dependent and -independent techniques. Qualitatively, these approaches suggested similar results, highlighting the presence of several fungal taxa able to produce mycotoxins. In-vitro isolation of fungal species suggest a higher frequency of Penicillium, while metabarcoding suggest a higher abundance of Alternaria. This discrepancy might reside on the targeted portion of the community (alive vs. overall) or in the specific features of each technique. Thus, this study shows that commercial wheat flour hosts a wide fungal diversity with several taxa potentially representing concerns for consumers, aspects that need more attention throughout the food production chain.