Search Results (73)

Alternaria mycotoxins represent a significant and emerging concern in the field of food safety due to their widespread occurrence in diverse food and feed commodities, including cereals, tomatoes, oilseeds, and dried fruits. Among these, alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and altertoxin-I (ATX-I) are the most frequently detected, often co-occurring at varying concentrations, thereby increasing the complexity of exposure and risk assessment. The gastrointestinal tract (GIT) is a crucial target of these toxins, as well as the liver, particularly considering its detoxifying role. Nevertheless, despite being a source of possible gastrointestinal and hepatic toxicity, there is still scarce data on the toxicokinetics of Alternaria toxins, on their mode of action, and respective toxic effects. To date, in vitro studies have shown that different Alternaria mycotoxins exhibit diverse toxicological effects, which may be dependent on their chemical structure. AOH and ATX-I have shown genotoxicity and cytotoxicity, mainly through interaction with the DNA and apoptosis, respectively. Tentoxin (TEN) has displayed hepatotoxic potential via impairment of detoxification pathways, and altenuene (ALT) has revealed lower toxicity. In vivo, AME and ATX-II revealed genotoxicity, while AOH and ATX-I showed context-dependent variability in their effects. Altogether, this review emphasizes that there is still a great lack of knowledge on these mycotoxins and an urgent need for more comprehensive toxicological and occurrence data to support proper risk assessment and, ultimately, regulatory decision-making. Full article

Emerging Alternaria mycotoxins tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT) and tentoxin (TEN) were detected in samples of spices and herbs. A total of 92 samples purchased in Italian markets were analyzed by using a UPLC-MS/MS method. TeA was the predominant mycotoxin with the highest percentage of positive samples (53%), followed by AME, AOH and TEN with overall means of 801.5, 2.4, 6.2 and 10.8 µg/kg, respectively. All samples were negative to ALT. The spices with higher levels of mycotoxins were flax seeds, paprika, red chili and licorice; regarding herbs, they were basil, sage and oregano. While TeA was found to be the most abundant mycotoxin equally in Italian and Lebanese samples, AOH and AME showed significantly lower levels in Italian samples, as Lebanese samples contained concentrations up to 14 times higher. Considering the mean levels of TeA in samples, the daily consumption of >8.7 g of flax seeds, >9.3 g of paprika and >5.8 g of red chili will exceed the threshold of toxicological concern (TTC) of TeA, which is 1500 ng/kg bw for a day. The high percentage of positive samples and the high levels of some mycotoxins observed demonstrate the susceptibility of spices and herbs to Alternaria mycotoxin contamination. These results provide an overview of emerging Alternaria mycotoxins in spices and herbs marketed in Italy and represent a valuable starting point to assess human exposure and support future studies aimed at establishing safe limits to protect human health. Full article

Mycotoxin contamination is a global threat to food safety and human health, especially in regions facing food insecurity, such as Sub-Saharan Africa. This intervention study evaluates the effectiveness of nixtamalization, a traditional alkaline cooking method, in reducing mycotoxin levels in maize and corresponding urinary biomarkers of exposure. Forty adult healthy volunteers from an informal settlement in Kliptown, Soweto (South Africa), were randomly assigned to consume control maize or visibly moldy maize subjected to nixtamalization. Nixtamalization achieved a reduction in fumonisin B3 and deoxynivalenol (DON) to unquantifiable or undetectable levels in maize, while reducing fumonisin B1 (FB1), fumonisin B2, and zearalenone (ZEN) by 95%, 95%, and 89%, respectively. Aflatoxin B1 was unquantifiable before and eliminated after treatment. Biomarker analysis revealed that after consumption of either control or nixtamalized maize, urinary levels of FB1, ZEN, and its metabolites α- and β-zearalenol (α- and β-ZEL) did not show significant differences between groups (p > 0.05). DON and tenuazonic acid levels were not affected by the intervention (p > 0.05), with urinary detection frequencies remaining above 90%. These results demonstrate nixtamalization effectively lowers mycotoxin levels in maize, resulting in exposure levels comparable to control maize, and highlight human biomonitoring as a sensitive tool for evaluating food safety interventions. Full article

Cereal contamination by mycotoxins represents a major food safety concern. This study aimed to assess the co-occurrence of 15 mycotoxins in 50 couscous samples marketed in Algeria using HPLC/FLD and LC-MS/MS techniques. The samples included various couscous types, differing in ingredients, production method (organic or conventional), processing operations, and granularity. The most frequently detected mycotoxins were tentoxin (76%), deoxynivalenol (74%), tenuazonic acid (72%), and ochratoxin A (54%). For the regulated mycotoxins, none of the concentrations exceeded the maximum levels set by the European Union. In contrast, tenuazonic acid and tentoxin, which are not yet regulated, were the most common compounds detected. Contamination with multiple mycotoxins was commonly observed: 90% of the samples contained at least two mycotoxins, with some containing up to seven. The most frequent combination involved tenuazonic acid-tentoxin-ochratoxin A. These findings highlight the need for frequent and systematic monitoring of couscous and other processed cereal-based products. Full article

This study aimed to assess the prevalence of four Alternaria toxins (alternariol [AOH], alternariol monomethyl ether [AME], tenuazonic acid [TeA], and tentoxin [TEN]) in various foods and assess the risk of Alternaria-toxin exposure in Zhejiang Province, China. A total of 325 samples were collected in this study, and at least one type of Alternaria toxin was detected in 53.85% of the samples. Wheat flour had a high detection rate of 97.41%, and TeA was the most prevalent compound in terms of concentration and detection rate. Assessment of Alternaria toxins using the threshold of toxicological concern (TTC) method showed that the majority of the population had a low exposure risk. Population-wide dietary exposure assessment suggested a potential health risk for some residents with 95th percentile (P95) assessment values 0.0038, 0.0128, and 0.0047 µg/kg b.w. for AOH from wheat flour and AOH and AME from Coix rice, respectively, exceeding the TTC value of 0.0025 µg/kg b.w. Probabilistic assessment showed that the mean exposure of children aged ≤6 years to AOH via wheat flour for P92 and of those aged 7–12 years for P93 were both 0.0025 µg/kg b.w. Exposures to TeA and TEN were within the acceptable limits (below the TTC value of 1.5 µg/kg b.w.). Age-group probabilistic and point assessments indicated that children aged ≤6 and 7–12 years are at higher exposure risk. This study provides a useful reference for developing limiting values and legislation for Alternaria toxins in food. Full article

This study investigated the occurrence of fungi and mycotoxins throughout the rice processing chain, from paddy rice to final white rice, in two rice varieties (variety I and variety II). A total of 75 fungal isolates were identified, belonging to the genera Penicillium, Alternaria, Aspergillus, Fusarium, and Talaromyces. Variety I exhibited a higher prevalence of Penicillium and Alternaria, whereas Variety II was dominated mainly by Alternaria, accounting for 63% of all isolates. Multi-mycotoxin screening of 22 mycotoxins revealed contamination by tenuazonic acid (TeA), zearalenone (ZEN), and 15-acetyl-deoxynivalenol (15-AcDON), with TeA concentrations exceeding 4000 µg/kg in whitened rice of variety II. Cluster analysis showed paddy and brown rice grouping together due to higher fungal loads and toxin levels, whereas whitened and final white rice clustered separately, reflecting reduced fungal counts but persistence of TeA, 15-AcDON, ZEN, and citrinin (CIT). The co-clustering of Alternaria with TeA and ZEN indicates strong field-related contamination. Although processing significantly decreased fungal loads, residual toxins persisted, emphasizing that rice polishing does not fully mitigate mycotoxin risks. These findings underscore the need for comprehensive surveillance and integrated management practices across the rice supply chain to minimize potential health hazards associated with fungal contaminants and their toxic metabolites. Full article

A study was carried out to identify the filamentous fungi and yeasts present in rotten wine grapes from two subzones of the Southern oasis of Mendoza winegrowing region, to assess the occurrence of tenuazonic acid (TA), a mycotoxin produced by the Alternaria genus, and to evaluate the wine spoilage potential of the associated yeasts in vitro and during microvinifications. The main fungal genera present were Alternaria (69.3%), followed by Aspergillus (16.8%), Penicillium (9.3%), and Cladosporium (4.6%), while the dominant yeast species Metschnikowia pulcherrima (23.1%), Aureobasidium pullulans (20.2%) and Hanseniaspora uvarum (13.0%) were followed by H. vineae (11.6%), Zygosaccharomyces bailii (10.4%), and H. guilliermondii (9.2%). Additionally, 94.1% of the rotten samples were contaminated with TA, with the highest level found in the Cabernet Sauvignon variety. No geographic association was found in the incidence of the different fungal genera or yeast species, nor in the occurrence of TA. Almost all of the tested yeasts produced H₂S, the majority of the Hanseniaspora strains produced acetic acid, and only one M. pulcherrima strain produced off-flavours in in vitro tests. Wines co-fermented with H. uvarum L144 and S. cerevisiae showed higher volatile acidity and lower fruity aroma and taste intensity. Therefore, processing bunch rot could pose a toxicological and microbiological risk to winemaking due to the high incidence of Alternaria and TA, as well as the potential of the associated yeasts to spoil wine. Full article

Concerns about mycotoxin contamination by Alternaria spp. in tomato-based products emphasize the need for understanding the effect of the environment on their production. In the current study, we focused on three species frequently associated with tomato (A. alternata, A. solani, and A. tenuissima) by evaluating the effects of different temperatures (5 to 40 °C) and substrata (PDA and V8) on mycelial growth and the production of mycotoxins (alternariol, alternariol monomethyl ether, and tenuazonic acid). Both biological processes were supported between 5 and 35 °C, with optimal temperatures between 20 and 30 °C, depending on the species. Temperature and its interaction with species significantly (p < 0.05) affected both processes. However, the species factor alone was not significant (p > 0.05), indicating that environmental conditions affect Alternaria spp. growth and mycotoxin production more than the species itself does. Mathematical equations were developed to describe the effect of temperature on mycelial growth, as well as on the production of AOH, AME, and TeA, for each Alternaria species. High concordance (CCC ≥ 0.807) between observed and predicted data and low levels of residual error (RMSE ≤ 0.147) indicated the high goodness of fit of the developed equations, which may be used for the development of models to predict Alternaria contamination both in field and during post-harvest storage. Full article

Alternaria species are important fungal pathogens occurring worldwide in wheat, causing both productive and qualitative losses, and posing a toxicological risk to human health due to the production of their mycotoxins in kernels. This study aimed to investigate the occurrence of Alternaria species and their mycotoxins in 48 wheat grain samples collected from the northeast to the southeast of Algeria. Seventy-two representative Alternaria strains were molecularly analyzed using a multi-locus sequence approach and evaluated for their capability to produce mycotoxins under in vitro conditions. Alternaria alternata, representing 42% of the strains, was the dominant species, followed to a lesser extent by species included in the Infectoriae section (26%). In addition, three species not previously reported in Algerian wheat, A. eureka, A. consortialis and A. tellustris, were identified, accounting for 5% of the total strains. Mycotoxin analyses showed high contamination of grains with alternariol monomethyl ether, alternariol and tenuazonic acid, occurring in 75, 69 and 35% of the samples, respectively. Moreover, 41 out of 48 samples showed the co-occurrence of multiple Alternaria mycotoxins. This study provides, for the first, time a clear picture of the occurrence and the distribution of Alternaria species on wheat in Algeria. Finally, the extensive monitoring activities carried out revealed the great biodiversity of Alternaria species able to colonize wheat grains. Moreover, findings on mycotoxin contamination raise concerns about the significant mycotoxigenic risk in Algerian wheat, emphasizing the need for strict monitoring and regulatory measures on Alternaria mycotoxins in food and feed. Full article

Alternaria species produce diverse secondary metabolites that act as critical virulence factors during plant pathogenesis. In cultivation areas of Chrysanthemum morifolium ‘Fubai’—a key cultivar for herbal tea—black spot disease caused by A. alternata manifests as necrotic leaf lesions progressing to wilting. Despite this disease’s economic impact, information on its associated toxins is limited, and the types of toxins produced by the black spot pathogen of Chrysanthemum morifolium ‘Fubai’ in particular remain unclear. Furthermore, whether toxins are present in the flowers when the leaves show symptoms is uncertain, but their inflorescence is not visibly infected. Using two previously characterized A. alternata strains (F16/F20) isolated from ‘Fubai’ in earlier studies, we demonstrated the concomitant production of altenuene (ALT) and tenuazonic acid (TeA) in both strains, with strain-specific yield variations (F20 TeA: 342.16 µg/mL vs. F16: 21.84 µg/mL; ALT: 0.28 µg/mL vs. 0.90 µg/mL). Time-course monitoring revealed coordinated accumulation of both toxins in inoculated petals, reaching 18.07 μg/g ALT and 2.59 µg/g TeA by day 9. Notably, these two toxins were detected only in flower samples from black spot-infected plants, and their concentrations correlated closely with disease severity in the leaves. Moreover, although the inflorescences did not display symptoms, both fresh and dried flowers retained detectable toxin levels. We established a technical system for the extraction and quantitative detection of the toxins ALT and TeA produced by the black spot pathogen in tea chrysanthemum. This work provides the first confirmation of ALT/TeA co-contamination in Chrysanthemum morifolium ‘Fubai’, revealing substantial dietary exposure risks through tea consumption. Our findings suggest that, from a food safety risk reduction perspective, integrated management strategies should be developed to minimize toxin contamination in tea chrysanthemum, including improved disease prevention measures and potential regulatory considerations. Full article

During postharvest storage, the yellow peach (Amygdalus persica) is susceptible to infection by Alternaria alternata, which causes fruit decay and produces multiple Alternaria toxins (ATs), leading to economic losses and potential health risks. The present study investigated the inhibitory effects of infrared radiation treatment against A. alternata on yellow peaches. Our in vitro experimental results indicated that infrared radiation at 50 °C for 30 min could completely inhibit fungal growth and AT production. Furthermore, infrared treatments prior to cold storage effectively delayed the onset of decay and significantly reduced the lesion diameter, decay rate, and AT levels in the yellow peaches inoculated with A. alternata. After the peaches underwent infrared radiation at 50 °C for 30 min and then cold storage for 60 days, the levels of tenuazonic acid, alternariol, alternariol methyl ether, and altenuene in the yellow peaches decreased by 95.1%, 98.6%, 76.1%, and 100.0%, respectively. Additionally, infrared radiation caused slight changes in their firmness, total soluble solids, and concentrations of sugar and organic acids, indicating minor negative impacts on the quality of the yellow peaches. Therefore, the present work provides a novel strategy for controlling A. alternata and AT contamination, thereby extending the shelf-life of yellow peaches, and improving food safety administration. Full article

Alternaria toxins (ATs) are a group of toxins produced by Alternaria fungi that frequently contaminate tomatoes and tomato products. Recently, the European Food Safety Authority evaluated ATs for their genotoxic and carcinogenic properties. Alternaria infestation is often controlled using ad hoc treatment strategies (fungicides). In this study, two analytical methods were developed, validated and applied for the determination of five ATs and 195 pesticides in tomato products collected from the Italian market. Two distinct groups, organic (n = 20) and conventional (n = 20) Italian tomato sauces, were characterized in depth. Tenuazonic acid, alternariol and alternariol monomethyl ether were found up to 517, 27 and 7.1 µg/kg, respectively, while pesticides were detected between 0.0026 and 0.0421 mg/kg in conventional products, and, interestingly, up to 0.0130 mg/kg in organic products. No correlation emerged between the detected levels of ATs and pesticides and the type of tomato cultivation, but the probability of pesticide contamination in conventional products was eight times higher than in organics. Some considerations about exposure assessment and risk characterization for ATs were also proposed in the overall population and in more sensitive and/or exposed subgroups, underlining the need for new focused toxicological and monitoring studies to establish reliable reference values. Moreover, these data highlight that fungicide treatments may not protect tomatoes from ATs contamination, although it may remove fungi infestation. As organic product consumption is increasing, it is important to lay down dedicated regulations for maximum permitted levels to ensure the food safety of these products that are often perceived by consumers as a healthier and environmentally friendlier choice. Full article

In this paper, we present a novel class of hybrid polyketides, tenuazamines A–H (1–8), which exhibit a unique tautomeric equilibrium from Alternaria alternata FL7. The elucidation of the structures was achieved through a diverse combination of NMR, HR-ESIMS, and ECD methods, with a focus on extensive spectroscopic data analysis. Notably, compounds 1, 4, 8–9 exhibited potent toxic effects on the growth of Arabidopsis thaliana. This research expands the structural diversity of tenuazonic acid compounds derived from endophytic fungi and provides potential hit compounds for the development of herbicides. Full article

Tenuazonic acid (TeA), usually found in cereals, fruits, vegetables, oil crops, and their products, was classified as one of the highest public health problems by EFSA as early as 2011, but it has still not been regulated by legislation due to the limited toxicological profile. Moreover, it has been reported that the coexistence of TeA and patulin (PAT) has been found in certain agricultural products; however, there are no available data about the combined toxicity. Considering that the gastrointestinal tract is the physiological barrier of the body, it would be the first target site at which exogenous substances interact with the body. Thus, we assessed the combined toxicity (cell viability, ROS, CAT, and ATP) in Caco-2 cells using mathematical modeling (Chou-Talalay) and explored mechanisms using non-targeted metabolomics and molecular biology methods. It revealed that the co-exposure of TeA + PAT (12.5 μg/mL + 0.5 μg/mL) can induce enhanced toxic effects and more severe oxidative stress. Mechanistically, the lipid and amino acid metabolisms and PI3K/AKT/FOXO signaling pathways were mainly involved in the TeA + PAT-induced synergistic toxic effects. Our study not only enriches the scientific basis for the development of regulatory policies but also provides potential targets and treatment options for alleviating toxicities. Full article

Mycotoxins, natural toxins produced by fungi, contaminate nearly 80% of global food crops. Alternaria mycotoxins, including alternariol (AOH), alternariol monomethylether (AME), and tenuazonic acid (TeA), present a health concern due to their prevalence in various plants and fruits. Exposure to these toxins exceeds the threshold of toxicological concern in some European populations, especially infants and toddlers. Despite this, regulatory standards for Alternaria toxins remain absent. The lack of toxicokinetic parameters, reference levels, and sensitive detection methods complicates risk assessment and highlights the necessity for advanced biomonitoring (HBM) techniques. This study addresses these challenges by developing and validating ultra-high performance liquid chromatography method coupled with tandem mass spectrometry to quantify AOH, AME, TeA, and their conjugates in multiple biological matrices. The validated method demonstrates robust linearity, precision, recovery (94–111%), and sensitivity across urine (LOD < 0.053 ng/mL), capillary blood (LOD < 0.029 ng/mL), and feces (LOD < 0.424 ng/g), with significantly lower LOD for TeA compared to existing methodologies. The application of minimally invasive microsampling techniques for the blood collection enhances the potential for large-scale HBM studies. These advancements represent a step toward comprehensive HBM and exposure risk assessments for Alternaria toxins, facilitating the generation of data for regulatory authorities. Full article