Assessment of Deoxynivalenol in Wheat, Corn and Its Products and Estimation of Dietary Intake

Prediction of Deoxynivalenol Contamination in Wheat via Infrared Attenuated Total Reflection Spectroscopy and Multivariate Data Analysis

The climate crisis further exacerbates the challenges for food production. For instance, the increasingly unpredictable growth of fungal species in the field can lead to an unprecedented high prevalence of several mycotoxins, including the most important toxic secondary metabolite produced by Fusarium spp., i.e., deoxynivalenol (DON). The presence of DON in crops may cause health problems in the population and livestock. Hence, there is a demand for advanced strategies facilitating the detection of DON contamination in cereal-based products. To address this need, we introduce infrared attenuated total reflection (IR-ATR) spectroscopy combined with advanced data modeling routines and optimized sample preparation protocols. In this study, we address the limited exploration of wheat commodities to date via IR-ATR spectroscopy. The focus of this study was optimizing the extraction protocol for wheat by testing various solvents aligned with a greener and more sustainable analytical approach. The employed chemometric method, i.e., sparse partial least-squares discriminant analysis, not only facilitated establishing robust classification models capable of discriminating between high vs low DON-contaminated samples adhering to the EU regulatory limit of 1250 μg/kg but also provided valuable insights into the relevant parameters shaping these models.

Combined exposure to deoxynivalenol facilitates lipid metabolism disorder in high-fat-diet-induced obesity mice

Deoxynivalenol (DON) is a trichothecene toxin that mainly produced by strains of Fusarium spp. DON contamination is widely distributed and is a global food safety threat. Existing studies have expounded its harmful effects on growth inhibition, endocrine disruption, immune function impairment, and reproductive toxicity. In energy metabolism, DON suppresses appetite, reduces body weight, triggers lipid oxidation, and negatively affects cholesterol and fatty acid homeostasis. In this study, high-fat diet (HFD) induced obese C57BL/6J mice were orally treated with 0.1 mg/kg bw/d and 1.0 mg/kg bw/d DON for 4 weeks. The lipid metabolism of mice and the molecular mechanisms were explored. The data showed that although DON reduced body weight and fat mass in HFD mice, it significantly increased their serum triglyceride concentrations, disturbance of serum lipid metabolites, impaired glucose, and resulted in insulin intolerance in mice. In addition, the transcriptional and expression changes of lipid metabolism genes in the liver and epididymis (EP) adipose indicate that the DON-mediated increase in serum triglycerides is caused by lipoprotein lipase (LPL) inhibition in EP adipose. Furthermore, DON down-regulates the expression of LPL through the PPARγ signaling pathway in EP adipose. These results are further confirmed by the serum lipidomics analysis. In conclusion, DON acts on the PPARγ pathway of white adipose to inhibit the expression of LPL, mediate the increase of serum triglyceride in obese mice, disturb the homeostasis of lipid metabolism, and increase the risk of cardiovascular disease. This study reveals the interference mechanism of DON on lipid metabolism in obese mice and provides a theoretical basis for its toxic effect in obese individuals.

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.

Evaluation of ELISA and immunoaffinity fluorometric analytical tools of four mycotoxins in various food categories

Mycotoxins (MTs) are secondary toxic metabolites that can contaminate food, impacting quality and safety, leading to various negative health effects and serious pathological consequences conferring urgent need to evaluate and validate the currently standard methods used in their analysis. Therefore, this study was aimed to validate ELISA and VICAM immunoaffinity fluorometric, the two common methods used to monitor the level of MTs according to the Egyptian Organization for Standardization and Quality Control. A total of 246 food samples were collected and tested for Aflatoxins (196 samples), Ochratoxin A (139), Zearalenone (70), and Deoxynivalenol (100) using both analytical methods. Results showed that aflatoxins exceeded limits in 42.9, 100, and 13.3% of oily seeds, dried fruits, and chili and spices, respectively. For ochratoxin A, 3.9% of Gramineae and 8% of spices and chili (locally sourced) exceeded the limits, while 17.6% of imported pasta and noodles exceeded the limits for deoxynivalenol. Significant differences for the aflatoxins and ochratoxin A detection among different categories of chocolate, dried fruits, and oily seeds (p-value < 0.05). No zearalenone contamination was detected in the exported, imported, and locally sourced categories. No deoxynivalenol contamination was detected in the tested Gramineae category. In contrast, for pasta and noodles, the imported samples exhibited the highest contamination rate (above the upper limit of 750 µg/kg) with 17.6% of the samples testing positive for deoxynivalenol with no significant difference among different sample categories of Gramineae, pasta, and noodles (p-value > 0.05). In conclusion, our study found no significant differences between the ELISA and immunoaffinity fluorometric analysis in the detection of the respective MTs in various food categories and therefore, they can substitute each other whenever necessary. However, significant differences were observed among different food categories, particularly the local and imported ones, highlighting the urgent need for strict and appropriate control measures to minimize the risk of MTs adverse effects.

3-Acetyldeoxynivalenol induces apoptosis, barrier dysfunction and endoplasmic reticulum stress by inhibiting mTORC1-dependent autophagy in porcine enterocytes

3-Acetyldeoxynivalenol (3-Ac-DON), an acetylated form of deoxynivalenol, is widely present in mycotoxin-contaminated food, feed as well as in other natural sources. Ingestion of 3-Ac-DON may result in intestinal dysfunction, leading to gut diseases in humans and animals. Nevertheless, the molecular mechanism of 3-Ac-DON in intestinal epithelial cytotoxicity remains unclear. In this study, intestinal porcine epithelial cell line 1 (IPEC-1) cells were treated with different concentrations of 3-Ac-DON for 12 h or 24 h, respectively. The results showed that 3-Ac-DON caused decreased cell viability, cell cycle arrest in G1 phase and depolarization of mitochondrial membrane potential. Western blotting analysis showed that 3-Ac-DON significantly decreased the expression of tight junction proteins, inhibited autophagy and activated endoplasmic reticulum (ER) stress in IPEC-1 cells (P < 0.05). Further investigation demonstrated that 3-Ac-DON caused apoptosis, ER stress and barrier dysfunction were reversed after co-treatment with the autophagy activator rapamycin (100 nM), indicating that autophagy plays a key role in the process of 3-Ac-DON-induced cell damage. In addition, we demonstrated that 3-Ac-DON inhibits the occurrence of autophagy mediated by mTORC1 protein. In conclusion, our research indicated that the mTORC1 protein and autophagy played a key role in the 3-Ac-DON-induced cytotoxic in IPEC-1 cells, which would provide new therapeutic targets and ideas for 3-Ac-DON-mediated intestinal injury.

Type B Trichothecenes in Cereal Grains and Their Products: Recent Advances on Occurrence, Toxicology, Analysis and Post-Harvest Decontamination Strategies

Type B trichothecenes (deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol) and deoxynivalenol-3-glucoside (DON-3G) are secondary toxic metabolites produced mainly by mycotoxigenic Fusarium fungi and have been recognized as natural contaminants in cereals and cereal-based foods. The latest studies have proven the various negative effects of type B trichothecenes on human health. Due to the widespread occurrence of Fusarium species, contamination by these mycotoxins has become an important aspect for public health and agro-food systems worldwide. Hence, their monitoring and surveillance in various foods have received a significant deal of attention in recent years. In this review, an up-to-date overview of the occurrence profile of major type B trichothecenes and DON-3G in cereal grains and their toxicological implications are outlined. Furthermore, current trends in analytical methodologies for their determination are overviewed. This review also covers the factors affecting the production of these mycotoxins, as well as the management strategies currently employed to mitigate their contamination in foods. Information presented in this review provides good insight into the progress that has been achieved in the last years for monitoring type B trichothecenes and DON-3G, and also would help the researchers in their further investigations on metabolic pathway analysis and toxicological studies of these Fusarium mycotoxins.

Natural Emulsions Based on Essential Oils as Antifungal and Antimycotoxicogenic Agents on Wheat for Bakery Industry

This study aimed to investigate the antifungal and antimycotoxicogenic effect of binary and tertiary mixtures of Thymus vulgaris, Origanum sativum, and Coriandrum sativum essential oils (EOs), as well as emulsions based on EO mixtures, on fungi developed on wheat grains destined for the bakery industry. The chemical composition of the EO mixtures, the physical characteristics of the emulsions, and the influence of treatments on the proximate composition of wheat seeds were also studied. The methods used included the microbiological analysis of fungi developed on wheat seeds, the ELISA technique for determining the deoxynivalenol content (DON), gas chromatography coupled with mass spectrometry (GC-MS) to detect the chemical composition of the EOs, Zetasizer to analyse the particle sizes and their electric charge at the surface, and NIR analysis of the proximate composition of wheat. The chemical composition analysis revealed that thymol and o-cymene were the major components in the binary mixture of the EOs with thyme, linalool in the binary mixtures of the EOs with coriander and carvacrol, and o-cymene in the binary mixtures of the EOs with oregano. The results showed that, based on the zeta potential, the tertiary mixture ensured maximum emulsion stability, while the emulsion based on thyme and oregano was the less stable system. Regarding the antifungal and antimycotoxicogenic effect, the results showed that the highest inhibition potential on fungi was observed with the binary mixtures of the EOs based on thyme and oregano, and on deoxynivalenol (DON) when the binary emulsion based on the same EOs was applied to wheat seeds. The proximate composition of wheat seeds contaminated with DON showed an increase in protein content and mineral substances, and there were changes in the colour of the wheat seeds after treatment with the EOs. In conclusion, the results obtained in this study showed the possibility of using binary/tertiary mixtures of EOs and emulsions as healthy and environmentally friendly alternatives in the bakery industry.

Deoxynivalenol exposure during pregnancy has adverse effects on placental structure and immunity in mice model

Deoxynivalenol (DON), a highly prevalent food contaminant, is known to induce reproductive and immunotoxicity in humans upon exposure. The present study focused on the consequences of exposure to DON during pregnancy for placental barrier and immune function, as well as fetal survival. Female mice received diets contaminated with DON (6.25 and 12.5 mg/kg of diet), starting immediately after mating until the end of the experiment. On day 17 of pregnancy the animals were killed, and maternal and fetal samples were collected for further analysis. Feeding on DON-contaminated diets decreased fetal survival, and DON was detected at significant levels in the fetus. Placentae from DON-exposed mice revealed a reduction in expression of junctional proteins, ZO-1, E-cadherin and claudins, upregulation of AHR mRNA expressions, and increase in IFN-ꝩ, IL-6 and IL-4 production. In conclusion, results of this study demonstrate harmful effects of DON on the course of pregnancy and fetal survival, which might be due to immunological changes in maternal immune organs and placenta. Altogether, these data underline the importance of the quality of maternal diet during pregnancy as they clearly demonstrate the potential harmful effects of a commonly present food-contaminant.

Protective Effects of Taraxasterol against Deoxynivalenol-Induced Damage to Bovine Mammary Epithelial Cells

Deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, is one of the most prevalent contaminants in livestock feed and causes very large losses to animal husbandry every year. Taraxasterol, isolated from Taraxacum officinale, has anti-inflammatory, antioxidative stress, and antitumor effects. In the present study, bovine mammary epithelial cells (MAC-T) were used as a model, and different concentrations of taraxasterol (0, 1, 5, 10, and 20 μg/mL) were used to protect against DON-induced cell damage. The results showed that taraxasterol at a concentration of 10 μg/mL significantly increased cell viability. Analysis of lactate dehydrogenase (LDH) levels indicated that taraxasterol substantially decreased LDH release caused by DON. Taraxasterol effectively alleviated the depletion of glutathione (GSH), the increase in the lipid peroxidation of malondialdehyde (MDA), the reduction in total superoxide dismutase (T-SOD) activity, and the decrease in total antioxidant capacity (T-AOC) induced by DON. The results further showed that taraxasterol reduced the accumulation of reactive oxygen species (ROS). Taraxasterol was found to relieve endoplasmic reticulum (ER) stress by suppressing the expression of glucose-regulated protein 78 kDa (GRP78), activating transcription factor 6 (ATF6), activating transcription factor 4 (ATF4) and the transcription factor C/EBP homologous protein (CHOP), and reducing cell apoptosis by suppressing the expression of caspase-3 and Bcl2-associated X (BAX) and upregulating the expression of the antiapoptotic protein B-cell lymphoma-2 (Bcl-2). Our research results indicate that taraxasterol could alleviate DON-induced damage to MAC-T cells.

Super-Sensitive LC-MS Analyses of Exposure Biomarkers for Multiple Mycotoxins in a Rural Pakistan Population

High levels of mycotoxin contamination have been reported in various food commodities in Pakistan, however, there has been no exposure assessment study using multiple mycotoxins' biomarkers. This study aimed to simultaneously assess the exposure to the five major mycotoxins: aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), ochratoxin A (OTA) and zearalenone (ZEN) in a Pakistani population using an integrated approach of human biomonitoring. Human urine samples (n = 292) were analyzed by a super-sensitive liquid-chromatography tandem mass spectrometry (LC-MS/MS) method. Rice and wheat were also collected and analyzed for mycotoxins by the LC-MS/MS method. Food consumption data were collected using a 24 h recall method. A high prevalence of urinary AFM1 (66%, mean ± SD 20.8 ± 41.3 pg/mL) and OTA (99%, 134.7 ± 312.0 pg/mL) were found, whilst urinary DON, FB1 and ZEN levels were low. The probable daily intake (PDI) derived from the urinary biomarkers revealed that 89% of the participants had exposure to OTA exceeding the established tolerable daily intake (TDI = 17 ng/kg bw/day). The average PDI of AFB1 for the studied population was 43 ng/kg bw/day, with rice as the main source of AFB1 exposure. In summary, exposure to AFB1 and OTA are of health concern and require further management.

Exposure to Deoxynivalenol During Pregnancy and Lactation Enhances Food Allergy and Reduces Vaccine Responsiveness in the Offspring in a Mouse Model

Deoxynivalenol (DON), a highly prevalent contaminant of grain-based products, is known to induce reproductive- and immunotoxicities. Considering the importance of immune development in early life, the present study investigated the effects of perinatal DON exposure on allergy development and vaccine responsiveness in the offspring. Pregnant mice received control or DON-contaminated diets (12.5 mg/kg diet) during pregnancy and lactation. After weaning, female offspring were sensitized to ovalbumin (OVA) by oral administration of OVA with cholera toxin (CT). Male offspring were injected with Influvac vaccine. OVA-specific acute allergic skin response (ASR) in females and vaccine-specific delayed-type hypersensitivity (DTH) in males were measured upon intradermal antigen challenge. Immune cell populations in spleen and antigen-specific plasma immunoglobulins were analyzed. In female CT+OVA-sensitized offspring of DON-exposed mothers ASR and OVA-specific plasma immunoglobulins were significantly higher, compared to the female offspring of control mothers. In vaccinated male offspring of DON-exposed mothers DTH and vaccine-specific antibody levels were significantly lower, compared to the male offspring of control mothers. In both models a significant reduction in regulatory T cells, Tbet+ Th1 cells and Th1-related cytokine production of the offspring of DON-exposed mothers was observed. In conclusion, early life dietary exposure to DON can adversely influence immune development in the offspring. Consequently, the immune system of the offspring may be skewed towards an imbalanced state, resulting in an increased allergic immune response to food allergens and a decreased immune response to vaccination against influenza virus in these models.

Variation of Deoxynivalenol Levels in Corn and Its Products Available in Retail Markets of Punjab, Pakistan, and Estimation of Risk Assessment

This study investigated the natural incidence of deoxynivalenol (DON) in corn and corn products from corn-producing districts of Punjab, Pakistan. The analysis was carried out using high performance liquid chromatography (HPLC) with UV detector and immunoaffinity cleanup columns. The detection limit (LOD) and limit of quantification were 25 and 50 µg/kg, respectively. A total of 1220 samples of corn and corn products were analyzed to detect DON, and 539 (44.2%) samples were observed to be contaminated with DON (n ≥ LOD). Furthermore, 92 (7.5%) samples of corn and corn products had DON levels that were higher than the proposed limits of the EU. The data are significantly different from a normal distribution of DON in samples of corn and corn products from different locations (p < 0.05) for Shapiro-Wilk and Kolmogorov-Smirnov values. However, a significant difference in DON levels was found between corn and corn-derived products (p ≤ 0.05). The lowest and highest exposures, and hazard quotient (HQ) values of 0.92 and 9.68 µg/kg bw/day, were documented in corn flour samples.

Patulin Contamination of Citrus Fruits from Punjab and Northern Pakistan and Estimation of Associated Dietary Intake

This research aims to assess the natural occurrence of patulin (PAT) in selected citrus fruits from central cities of Punjab and Pakistan's northern cities. A total of 2970 fruit samples from 12 citrus cultivars were examined using liquid chromatography fitted with a UV detector. The detection limit (LOD) and quantification limit were 0.04 and 0.12 µg/kg, respectively. About 56% of samples of citrus fruits from Punjab's central cities, Pakistan, were found to be contaminated with PAT, with values ranging from 0.12 to 1150 µg/kg in samples from central Punjab cities. Furthermore, 31.7% of samples of citrus fruits from northern cities of Pakistan were contaminated with PAT, with values ranging from 0.12 to 320 µg/kg. About 22.1% of citrus fruit samples had PAT levels greater than the suggested limits established by the European Union (EU). The dietary intake levels of PAT ranged from 0.10 to 1.11 µg/kg bw/day in the central cities of Punjab, Pakistan, and 0.13 to 1.93 µg/kg bw/day in the northern cities of Pakistan.

Biomonitoring of Aflatoxin B1 and Deoxynivalenol in a Rural Pakistan Population Using Ultra-Sensitive LC-MS/MS Method

There are limited data on exposure to mycotoxins in Pakistan. Here, we measured exposure to deoxynivalenol (DON), a common contaminant of wheat, and aflatoxin B1 (AFB1), a known contaminant of rice, using biomarkers of exposure. Wheat (n = 195) and rice (n = 62) samples were analyzed for AFB1 and DON levels, and the corresponding urinary biomarkers were analyzed in urine samples from a rural population (n = 264, aged 4-80 years, male 58%) using ultra-sensitive liquid chromatography-tandem mass spectrometry. AFB1 was detected in 66% of rice (5.04 ± 11.94 µg/kg) and 3% of wheat samples. AFM1 (hydroxylated form of AFB1)was detected in 69% of urine samples, mean 0.023 ± 0.048 ng/mL and DON was detected in 20% of urine samples, mean 0.170 ± 0.129 ng/mL. The maximum probable daily intake for DON derived from the urinary biomarker was 59.8 ng/kg b.w./day, which is below the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives' tolerable daily intake (1000 ng/kg b.w./day). However, for aflatoxin, the derived margin of exposure (MoE) of (13.2) was well below the safe MoE (10,000) suggested by the European Food Safety Authority. The calculated aflatoxin-associated cancer risk of 0.514/105 individuals/year suggests that measures should be taken to reduce the AFB1 contamination in food, particularly rice, in Pakistan.