Transfer of Fusarium mycotoxins and ‘masked’ deoxynivalenol (deoxynivalenol-3-glucoside) from field barley through malt to beer

The fate of five Fusarium toxins — deoxynivalenol (DON), sum of 15- and 3-acetyl-deoxynivalenol (ADONs), HT-2 toxin (HT-2) representing the main trichothecenes and zearalenone (ZON) during the malting and brewing processes — was investigated. In addition to these ‘free’ mycotoxins, the occurrence of deoxynivalenol-3-glucoside (DON-3-Glc) was monitored for the first time in a beer production chain (currently, only DON and ZON are regulated). Two batches of barley, naturally infected and artificially inoculated with Fusarium spp. during the time of flowering, were used as a raw material for processing experiments. A highly sensitive procedure employing high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was validated for the analysis of ‘free’ Fusarium mycotoxins and DON-conjugate in all types of matrices. The method was also able to detect nivalenol (NIV), fusarenon-X (FUS-X) and T-2 toxin (T-2); nevertheless, none of these toxins was found in any of the samples. While steeping of barley grains (the first step in the malting process) apparently reduced Fusarium mycotoxin levels to below their quantification limits (5–10 µg kg^?1), their successive accumulation occurred during germination. In malt, the content of monitored mycotoxins was higher compared with the original barley. The most significant increase was found for DON-3-Glc. During the brewing process, significant further increases in levels occurred. Concentrations of this ‘masked’ DON in final beers exceeded ‘free’ DON, while in malt grists this trichothecene was the most abundant, with the DON/DON-3-Glc ratio being approximately 5:1 in both sample series. When calculating mass balance, no significant changes were observed during brewing for ADONs. The content of DON and ZON slightly decreased by a maximum of 30%. Only traces of HT-2 were detected in some processing intermediates (wort after trub removal and green beer).     

Relationship between lutein and mycotoxin content in durum wheat

Levels of lutein and a number of mycotoxins were determined in seven varieties of durum wheat (Triticum durum) and two varieties of common wheat (Triticum aestivum) in order to explore possible relationships amongst these components. Durum wheat cultivars always showed both higher lutein and mycotoxin contents than common wheat cultivars. The mycotoxins detected in both common and durum wheat cultivars were produced by the genera Fusarium, Claviceps, Alternaria and Aspergillus. Fusarium was the major producer of mycotoxins (26 mycotoxins) followed by Claviceps (14 mycotoxins), which was present only in some cultivars such as Chevalier (common wheat), Lupidur and Selyemdur (both durum wheat), Alternaria (six mycotoxins) and Aspergillus (three mycotoxins). Positive correlations between the levels of lutein and mycotoxins in durum wheat cultivars were found for the following mycotoxins: deoxynivalenol (DON), its derivative DON-3-glucoside, moniliformin, culmorin and its derivatives (5-hydroxyculmorin and 15-hydroxyculmorin).     

Stability of DON and DON-3-glucoside during baking as affected by the presence of food additives

The mycotoxin deoxynivalenol (DON) is one of the most common mycotoxins of cereals worldwide, and its occurrence has been widely reported in raw wheat. The free mycotoxin form is not the only route of exposure; modified forms can also be present in cereal products. Deoxynivalenol-3-glucoside (DON-3-glucoside) is a common DON plant conjugate. The mycotoxin concentration could be affected by food processing; here, we studied the stability of DON and DON-3-glucoside during baking of small doughs made from white wheat flour and other ingredients. A range of common food additives and ingredients were added to assess possible interference: ascorbic acid (E300), citric acid (E330), sorbic acid (E200), calcium propionate (E282), lecithin (E322), diacetyltartaric acid esters of fatty acid mono- and diglycerides (E472a), calcium phosphate (E341), disodium diphosphate (E450i), xanthan gum (E415), polydextrose (E1200), sorbitol (E420i), sodium bicarbonate (E500i), wheat gluten and malt flour. The DON content was reduced by 40%, and the DON-3-glucoside concentration increased by >100%, after baking for 20 min at 180°C. This confirmed that DON and DON-3-glucoside concentrations can vary during heating, and DON-3-glucoside could even increase after baking. However, DON and DON-3-glucoside are not affected significantly by the presence of the food additives tested.     

The study of deoxynivalenol and its masked metabolites fate during the brewing process realised by UPLC–TOFMS method

The co-occurrence of deoxynivalenol (DON) and deoxynivalenol-3-glucoside (DON-3-Glc) has been recently reported in malt and beer. In this study, the concentration changes were monitored within the brewing process of four beer brands: light, dark tap and two lagers, produced from ground malt mixtures differing in composition, and also mycotoxins content. A simple and rapid method employing DON-dedicated immunoaffinity columns (IAC) for the selective pre-concentration, followed by ultra-performance liquid chromatography coupled to a time-of-flight mass spectrometer (UPLC–TOFMS) system for the reliable quantification at (ultra)trace levels, was validated for all experimental matrices. The results document the key role of the malt contamination nature. While in the first monitoring period a significant increase of both DON and DON-3-Glc occurred (up to 250% and 450%, respectively), fairly different trends were observed when new malts were used for identical technological processing (in some beers a decrease of DON and only a small increase of DON-3-Glc occurred). Worth noticing, that the outcome of the brewing process was surprisingly reproducible for a particular malt mixture. In the final phase, a small monitoring study comparing Czech and Austrian alcohol-free and conventional beers was carried out.     

Effects of phosphorus and zinc fertilizer on cadmium uptake and distribution in flax and durum wheat

Cadmium accumulation in crops presents a potential risk to human health. To understand the difference between dicotyledonous and monocotyledonous species in respect of Cd accumulation, and to develop fertilizer management practices to minimise Cd uptake, a growth chamber study was conducted to evaluate the interactive effects of Cd concentration in phosphate and Zn fertilizer on Cd uptake in flax (Linum usitatissimum L) and durum wheat (Triticum turgidum L). Cadmium concentration was higher in flax than durum wheat shoots. Cadmium concentration was lower and Zn concentration higher in the flax seed and durum wheat grain than in the root, shoot or straw of both species. These results suggest that flax has comparatively ineffective barriers discriminating against the transport of Cd from the root to the shoot via the xylem, and that both crops may restrict Cd translocation to the seed/grain via the phloem. Commercial grade monoammonium phosphate (NH₄H₂PO₄) or triple superphosphate (Ca(H₂PO₄)₂) produced higher seed Cd concentrations than did reagent grade P in flax but not in durum wheat. Application of P significantly decreased seed/grain Zn concentration and increased seed/grain Cd concentration. Zinc addition at 20 mg Zn kg^?1 soil with P decreased seed/grain Cd concentration (average 42.2% for flax, 65.4% for durum wheat), Cd accumulation (average 37.2% for flax, 62.4% for durum wheat) and Cd translocation to the seed/grain (average 20.0% for flax, 34.5% for durum wheat) in both crops. These results indicate that there is an antagonistic effect of Zn on Cd for root uptake and distribution within the plant. Copyright © 2004 Society of Chemical Industry     

Rapid and non-invasive analysis of deoxynivalenol in durum and common wheat by Fourier-Transform Near Infrared (FT-NIR) spectroscopy

Fourier transform near-infrared spectroscopy (FT-NIR) was used for rapid and non-invasive analysis of deoxynivalenol (DON) in durum and common wheat. The relevance of using ground wheat samples with a homogeneous particle size distribution to minimize measurement variations and avoid DON segregation among particles of different sizes was established. Calibration models for durum wheat, common wheat and durum + common wheat samples, with particle size <500 µm, were obtained by using partial least squares (PLS) regression with an external validation technique. Values of root mean square error of prediction (RMSEP, 306–379 µg kg^–1) were comparable and not too far from values of root mean square error of cross-validation (RMSECV, 470–555 µg kg^–1). Coefficients of determination (r ²) indicated an “approximate to good” level of prediction of the DON content by FT-NIR spectroscopy in the PLS calibration models (r ² = 0.71–0.83), and a “good” discrimination between low and high DON contents in the PLS validation models (r ² = 0.58–0.63). A “limited to good” practical utility of the models was ascertained by range error ratio (RER) values higher than 6. A qualitative model, based on 197 calibration samples, was developed to discriminate between blank and naturally contaminated wheat samples by setting a cut-off at 300 µg kg^–1 DON to separate the two classes. The model correctly classified 69% of the 65 validation samples with most misclassified samples (16 of 20) showing DON contamination levels quite close to the cut-off level. These findings suggest that FT-NIR analysis is suitable for the determination of DON in unprocessed wheat at levels far below the maximum permitted limits set by the European Commission.     

Impact of post-anthesis rainfall,fungicide and harvesting time on the concentration of deoxynivalenol and zearalenone in wheat

Field experiments were conducted to identify the impact of post-anthesis rainfall on the concentration of deoxynivalenol (DON) and zearalenone (ZON) in harvested wheat grain. Winter wheat plots were inoculated with Fusarium graminearum at stem extension (GS31) and prothioconazole was applied at mid-anthesis (GS65) to split plots and plots were subsequently mist irrigated for 5 days. Plots were either covered by polytunnels, irrigated by sprinklers or left as non-irrigated uncovered control plots after medium-milk (GS75). Plots were harvested either when ripe (GS92; early harvest) or three weeks later (late harvest). Fusarium head blight (FHB) was assessed each week from inoculation. At harvest, yield and grain quality was measured and grains were analysed for DON and ZON. Differences in rainfall resulted in contrasting disease pressure in the two experiments, with low FHB in the first experiment and high FHB in the second. Difference in FHB resulted in large differences in grain yield, quality and mycotoxin content. DON concentration was significantly (P < 0.05) higher in irrigated compared to covered and control plots in the first experiment, whereas in the second experiment, DON was significantly (P < 0.05) higher in the covered plots compared to the control and irrigated plots. ZON concentration was significantly (P < 0.05) higher in irrigated plots in both experiments. Later harvesting resulted in an approximate fivefold increase in ZON in the first experiment, but was not significantly different in the second experiment. Prothioconazole significantly (P < 0.05) reduced DON in both experiments, but gave inconsistent reductions to ZON. This is the first report to show that the post-anthesis rainfall can significantly increase ZON in wheat, which can increase further with a delayed harvest but may be significantly reduced with the application of prothioconazole. Importantly, in the absence of moisture late season, ZON remains at very low concentrations even when wheat is severely affected by FHB.     

Effect of fungicides on the development of Fusarium head blight,yield and deoxynivalenol accumulation in wheat inoculated under field conditions with Fusarium graminearum and Fusarium culmorum

The effect of different fungicide treatments on Fusarium head blight (FHB) development, grain yields and deoxynivalenol (DON) accumulation in wheat was evaluated after artificial inoculation under field conditions with a mixture of Fusarium graminearum and F culmorum. The trials were carried out using commercially available products on five different cultivars of soft and durum wheat (Serio, Genio, Bracco, Duilio and Orobel) in two separate experimental fields located in the North of Italy. Treatments with Tiptor^® S (cyproconazole plus prochloraz) and a mixture of Horizon^® 250 EW (tebuconazole) plus Amistar^® 250 SC (azoxystrobin) significantly reduced the FHB disease severity (by between 25 and 77%) and DON content (by between 32 and 89%) in the grain as compared with the inoculated control. Yields (tonne ha^?1) and thousand grain weight (TGW) were higher in plots subjected to fungicide treatments. Tetraconazole (Eminent^® 40 EW) showed a markedly reduced effectiveness compared with the other treatments. Regression analysis showed a strong correlation of disease severity with DON levels (positive correlation) and with yields or TGW (negative correlation) for individual cultivars and locations. Fusarium graminearum, F culmorum and F poae were the species most commonly isolated from all trials, including inoculated and non‐inoculated control plots. Copyright © 2004 Society of Chemical Industry     

Transfer of Fusarium mycotoxins and 'masked' deoxynivalenol (deoxynivalenol-3-glucoside) from field barley through malt to beer

The fate of five Fusarium toxins--deoxynivalenol (DON), sum of 15- and 3-acetyl-deoxynivalenol (ADONs), HT-2 toxin (HT-2) representing the main trichothecenes and zearalenone (ZON) during the malting and brewing processes--was investigated. In addition to these 'free' mycotoxins, the occurrence of deoxynivalenol-3-glucoside (DON-3-Glc) was monitored for the first time in a beer production chain (currently, only DON and ZON are regulated). Two batches of barley, naturally infected and artificially inoculated with Fusarium spp. during the time of flowering, were used as a raw material for processing experiments. A highly sensitive procedure employing high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was validated for the analysis of 'free' Fusarium mycotoxins and DON-conjugate in all types of matrices. The method was also able to detect nivalenol (NIV), fusarenon-X (FUS-X) and T-2 toxin (T-2); nevertheless, none of these toxins was found in any of the samples. While steeping of barley grains (the first step in the malting process) apparently reduced Fusarium mycotoxin levels to below their quantification limits (5-10 microg kg(-1)), their successive accumulation occurred during germination. In malt, the content of monitored mycotoxins was higher compared with the original barley. The most significant increase was found for DON-3-Glc. During the brewing process, significant further increases in levels occurred. Concentrations of this 'masked' DON in final beers exceeded 'free' DON, while in malt grists this trichothecene was the most abundant, with the DON/DON-3-Glc ratio being approximately 5:1 in both sample series. When calculating mass balance, no significant changes were observed during brewing for ADONs. The content of DON and ZON slightly decreased by a maximum of 30%. Only traces of HT-2 were detected in some processing intermediates (wort after trub removal and green beer).     

In vivo toxicity assessment of deoxynivalenol-contaminated wheat after ozone degradation

ABSTRACT

The effect of ozone on deoxynivalenol (DON) detoxification was investigated. Ozone treatment could significantly reduce the levels of DON in wheat; 53% of DON in wheat was decomposed with 90 mg l^–1 of ozone at a flow rate of 15 l min^–1 for 4 h. The safety of DON-contaminated wheats (DCWs) untreated/treated by ozone was also evaluated. Institute of Cancer Research (ICR) mice were divided into a standard diet group and five experimental diet groups for a 51-day orally administration experiment. In the experiment, no remarkable changes in the general appearance of the mice were observed, and all the mice survived until the scheduled necropsy. The results of sub-chronic toxicity indicated that mice fed on DCWs alone had significantly decreased in body weight gain, thymus and spleen weights, ratios of liver, thymus and spleen to body weight, blood indices (red blood cell, haemoglobin, white blood cell), and pro-inflammatory cytokines (interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α)), while showing a significant increase in alanine aminotransferase, aspartate aminotransferase, blood creatinine and blood urea nitrogen levels. Histopathological examination indicate that DON elicited some degree of toxicity on the liver, kidney and thymus tissue. Mice fed on DCWs treated by ozone mitigated the adverse effects compared with mice fed on DCWs. All the results suggested that the deleterious effects of DON could be highly reduced by ozone, and ozone itself shows minor toxic effects on animals in this process.     

Mycorrhizal colonization and grain Cd concentration of field‐grown durum wheat in response to tillage,preceding crop and phosphorus fertilization

BACKGROUND: A 3‐year field trial was conducted to investigate the effect of agricultural management practices including tillage, preceding crop and phosphate fertilization on root colonization by arbuscular mycorrhizal (AM) fungi and grain cadmium (Cd) concentration of durum wheat (Triticum turgidum L.). The relationship between grain Cd and soil and plant variables was explored to determine the primary factors affecting grain Cd concentration. RESULTS: Mycorrhizal colonization of the roots was reduced by conventional tillage or when the preceding crop was canola (Brassica napus L.), compared to minimum tillage or when the preceding crop was flax (Linum usitatissimum L.). In contrast, grain Cd was not consistently affected by any treatment. Grain Cd was generally below the maximum permissible concentration (MPC) of 100 µg Cd kg^?1 proposed by WHO. Grain Cd varied substantially from year to year, and could be predicted with 70% of variance accounted for by using the model: grain Cd concentration = ? 321.9 + 44.5× ln(grain yield) + 0.26× soil DTPA‐Cd + 182.5× soil electrical conductivity (EC)? 0.98× grain Zn concentration. CONCLUSIONS: These common agricultural management practices had no effect on grain Cd concentration in durum wheat though they impacted mycorrhizal colonization of roots. Grain yield and to a lesser extent soil conditions of EC and DTPA‐Cd and grain Zn influenced grain Cd, whereas mycorrhizal colonization levels did not. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd     

Application of ozone for degradation of mycotoxins in food: A review

Mycotoxins such as aflatoxins (AFs), ochratoxin A (OTA) fumonisins (FMN), deoxynivalenol (DON), zearalenone (ZEN), and patulin are stable at regular food process practices. Ozone (O₃) is a strong oxidizer and generally considered as a safe antimicrobial agent in food industries. Ozone disrupts fungal cells through oxidizing sulfhydryl and amino acid groups of enzymes or attacks the polyunsaturated fatty acids of the cell wall. Fusarium is the most sensitive mycotoxigenic fungi to ozonation followed by Aspergillus and Penicillium. Studies have shown complete inactivation of Fusarium and Aspergillus by O₃ gas. Spore germination and toxin production have also been reduced after ozone fumigation. Both naturally and artificially, mycotoxin‐contaminated samples have shown significant mycotoxin reduction after ozonation. Although the mechanism of detoxification is not very clear for some mycotoxins, it is believed that ozone reacts with the functional groups in the mycotoxin molecules, changes their molecular structures, and forms products with lower molecular weight, less double bonds, and less toxicity. Although some minor physicochemical changes were observed in some ozone‐treated foods, these changes may or may not affect the use of the ozonated product depending on the further application of it. The effectiveness of the ozonation process depends on the exposure time, ozone concentration, temperature, moisture content of the product, and relative humidity. Due to its strong oxidizing property and corrosiveness, there are strict limits for O₃ gas exposure. O₃ gas has limited penetration and decomposes quickly. However, ozone treatment can be used as a safe and green technology for food preservation and control of contaminants.     

Utilising an LC-MS/MS-based multi-biomarker approach to assess mycotoxin exposure in the Bangkok metropolitan area and surrounding provinces

Human exposures to mycotoxins through dietary intake are a major health hazard and may result in various pathophysiological effects. Although Thailand is a country at increased risk due to its climatic conditions, no comprehensive dataset is available to perform proper exposure assessment of its population with regard to mycotoxins. Therefore, this pilot study was conducted to investigate and evaluate the exposure levels of major mycotoxins (aflatoxin B₁, ochratoxin A, fumonisins, zearalenone and trichothecenes). Sixty first-morning urine samples were collected from healthy volunteers who live in the Bangkok metropolitan area and surrounding provinces (Pathumthani, Nonthaburi, Samutprakarn and Samutsakorn). Urine samples were analysed by a LC-MS/MS-based multi-biomarker method following a so-called ‘dilute and shoot’ approach. Results generally indicated low mycotoxin exposures in most individuals through the determination of the four biomarkers that were detected in urine samples, i.e. aflatoxin M₁, ochratoxin A (OTA), as well as the deoxynivalenol (DON) metabolites DON-3-glucuronide and DON-15-glucuronide in 10 of 60 individuals. The maximum concentrations were used to estimate the daily intake confirming that none of the individuals exceeded the tolerable daily intake (TDI) of DON (maximum 26% of TDI) or OTA (maximum 22% of TDI). However, the maximum exposure of aflatoxin B₁, estimated to be 0.91 µg (kg bw)^–1 day^–1, should raise some concerns and suggests further studies utilising a more sensitive method. Low exposure to Fusarium toxins was also confirmed by the absence of zearalenone, α-zearalanol, β-zearalanol and zearalenone-14-glucuronide as well as T-2 toxin, HT-2 toxin, nivalenol and free DON. This is the first multi-mycotoxin biomarker study performed in Southeast Asia.     

Mycoflora and deoxynivalenol in whole wheat grains (Triticum aestivum L.) from Southern Brazil

The fungal species Fusarium graminearum is related to deoxynivalenol (DON) formation. The aim of this study was to evaluate mycoflora and DON occurrence in 53 whole wheat grain samples collected in Southern Brazil during the 2012 crop. Wheat grains showed adequate values of water activity ranging from 0.48 to 0.72, within the required limits of moisture content, ranging from 9.1% to 13.9%. In addition, low counts of fungal colonies, ranging from 10 to 8.2 × 10², were found. For Fusarium genera, there was predominance of Fusarium verticillioides (34%) and F graminearum (30.2%). For Aspergillus species, 37.7% of Aspergillus flavus was determined. Regarding the Penicillium species, Penicillium digitatum (49%) was the most found species. DON was detected in 47.2% (25 out of 53) of the samples analysed, with levels ranging from 243.7 to 2281.3 µg kg^?1 (mean: 641.9 µg kg^?1).     

Effect of phosphate source,rate and cadmium content and use of Penicillium bilaii on phosphorus,zinc and cadmium concentration in durum wheat grain

Field studies were conducted over 3 years at several locations in Alberta and Manitoba, Canada to evaluate the impact of phosphate fertiliser containing varying concentrations of Cd on grain yield and P, Zn and Cd concentration in durum wheat grain. The effect of a seed treatment with Penicillium bilaii, a phosphate‐solubilising fungus, was also examined. P bilaii had little effect on crop yield, nutrient concentration or the concentration of Cd in the grain under the conditions of this study. Fertilisation with monoammonium phosphate consistently increased Cd concentration and Cd/Zn ratio and decreased Zn concentration in durum wheat. Increases in Cd concentration in durum wheat were unrelated to Cd concentration in the fertiliser, although the concentration of Cd in the fertiliser sources varied from 0.2 to 186.0 µg g^?1. Increased Cd concentration with phosphate application may be related to high ionic strength, reduced pH and enhanced root proliferation in the microregion around the fertiliser granules. Enhanced root development in response to phosphate fertilisation may increase the accumulation of Cd. Reduction in Zn accumulation associated with phosphate application may also contribute to the increase in Cd concentration in durum grain, possibly through enhancement of Cd translocation to the grain. While reduction in Cd concentration in phosphate fertilisers will reduce long‐term Cd accumulation in soils, use of low‐Cd fertiliser at commercially practical levels of fertilisation is unlikely to reduce Cd concentration in durum wheat in the year of application. © 2002 Society of Chemical Industry     

Analysis of deoxynivalenol, masked deoxynivalenol, and Fusarium graminearum pigment in wheat samples, using liquid chromatography-UV-mass spectrometry

Tolerable limits set for deoxynivalenol (DON) do not consider DON conjugates such as DON-3-glucoside. Conjugates may be metabolized in vivo to DON. Such masked mycotoxins and the potentially toxic Fusarium pigment are not routinely analyzed in cereals. We quantified DON, DON-3-glucoside, and a red Fusarium pigment in hard red spring wheat, using a new liquid chromatography-mass spectrometry method. Extraction protocols using centrifugation and shaking, and methanol-methylene chloride (50:50 [vol/vol]) or acetonitrile-water (84:16 [vol/vol]) were assessed. Purposively and randomly selected hard spring wheat samples were extracted with solvent filtered through a C18 column and analyzed using liquid chromatography-UV-mass spectrometry. Isocratic mobile phase (70% methanol) was used. Recoveries were 96.4% (DON) and 70.0% (DON-3-glucoside), while limits of detection were 1 microg/kg (MS) and 10 microg/kg (UV), and limits of quantification were 1 microg/kg (UV) and 0.5 microg/kg (MS), respectively. The pigment limits of quantification and limits of detection on the MS were 4.3 and 0.0005 microg/kg, respectively. The purposively selected samples had DON, DON-3-glucoside, and pigment averages of 3.4 +/- 4.0 microg/g, 3.8 +/- 8.3 microg/g, and 0.31 +/- 3.71 g/kg, respectively. The randomly selected spring wheat had lower mean levels of DON (1.4 +/- 2.3 microg/g), DON-3-glucoside (0.2 +/- 1.0 microg/g), and pigment (147.93 +/- 247.84 microg/g). Analytical tools such as this new liquid chromatography-UV-mass spectrometry method can be used to quantify masked and parent mycotoxins, plus a potentially toxic pigment for risk assessment.     

In vitro-cultured wheat spikes provide a simplified alternative for studies of cadmium uptake in developing grains

BACKGROUND: An immature wheat spike culture system was used to monitor cadmium (Cd) accumulation in grains, hulls and awns of bread wheat and durum wheat. Immature spikes were cultured prior to anthesis in a medium containing 50 g L^?1 sucrose and 0.4 g L^?1 L ‐glutamine, supplemented with 0, 0.1, 0.5, 1, 2, 3, 4, 5, 10, 15, 20 or 25 mg L^?1 cadmium chloride (CdCl₂). Grains were collected at maturity and their Cd accumulation was determined using inductively coupled plasma mass spectrometry (ICP‐MS). RESULTS: Cd accumulation at CdCl₂ concentrations of 3 mg L^?1 and above was higher in grains of durum wheat compared with bread wheat. In hulls a similar trend was observed at CdCl₂ concentrations above 15 mg L^?1. Starch concentration in grains increased slightly at 3 and 4 mg L^?1 CdCl₂. Cd accumulation negatively affected grain protein concentration. Expression patterns of Cd‐related genes glutathione reductase (TaGR), metallothionein (MT) and phytochelatin synthase (PCS) in spikes cultured in media containing 0, 5, 10, 15 and 25 mg L^?1 CdCl₂ at 5 days post‐anthesis showed that TaGR and PCS expression in bread wheat was up‐regulated at 5 mg L^?1 CdCl₂ but down‐regulated at other CdCl₂ concentrations. However, in durum wheat, expression of all three genes was down‐regulated or remained unchanged. CONCLUSION: This study demonstrates that immature spike culture can be used to study Cd accumulation in grains and can delineate hyper‐accumulating durum wheat from bread wheat at CdCl₂ concentrations of 2 mg L^?1 and above. Copyright © 2011 Society of Chemical Industry     

Deoxynivalenol in wheat,maize, wheat flour and pasta: surveys in Hungary in 2008–2015

Among Fusarium mycotoxins, deoxynivalenol (DON) is the most common contaminant in case of cereals and cereal-based foods in Hungary. In this study, Hungarian wheat (n = 305), maize (n = 108), wheat flour (n = 179) and pasta (n = 226) samples were analysed (N = 818). The samples were collected during 2008–2015 in Hungary. Applied methods of analysis were enzyme-linked immunosorbent assay and liquid-chromatography coupled with a mass spectrometer. Results were compared and evaluated with Hungarian weather data. Among cereal samples, in 2011, wheat was contaminated with DON (overall average ± standard deviation was 2159 ± 2818 µg kg^?1), which was above the maximum limit (ML). In case of wheat flour and pasta, no average values above ML were found during 2008–2015, but higher DON contamination could be observed in 2011 as well (wheat flour: 537 ± 573 µg kg^?1; pasta: 511 ± 175 µg kg^?1).     

Determination of Deoxynivalenol and Nivalenol in Wheat by Ultra-Performance Liquid Chromatography/Photodiode-Array Detector and Immunoaffinity Column Cleanup

An ultra-performance liquid chromatography (UPLC®) method has been developed for the simultaneous determination of deoxynivalenol (DON) and nivalenol (NIV) in wheat. Ground sample was extracted with water and the filtered extract was cleaned up through an immunoaffinity column containing a monoclonal antibody specific for DON and NIV. Toxins were separated and quantified by UPLC® with photodiode-array detector (λ?=?220 nm) in less than 3 min. Mean recoveries from blank wheat samples spiked with DON and NIV at levels of 100–2,000 μg/kg (each toxin) ranged from 85 to 95 % for DON and from 81 to 88 % for NIV, with relative standard deviations less than 7 %. Similar recoveries were observed from spiked samples when methanol/water (80:20, v/v) was used as extraction solvent. However, by using a wheat sample naturally contaminated with DON and NIV, the one-way analysis of variance (Student–Newman–Keuls test) between different extraction solvents and modes showed that water extraction provided a significant increase (P?<?0.001) in toxin concentrations (mean values of six replicate analyses) with respect to methanol/water (80:20, v/v). No significant difference was observed between shaking (60 min) and blending (3 min). The limit of detection (LOD) of the method was 30 μg/kg for DON and 20 μg/kg for NIV (signal-to-noise ratio 3:1). The immunoaffinity columns showed saturation of DON/NIV binding sites at levels higher than 2,000 ng in blank wheat extracts spiked with the corresponding amount of mycotoxin, as single mycotoxin or sum of DON and NIV. The range of applicability of the method was from LOD to 4,000 μg/kg, as single mycotoxin or sum of DON and NIV in wheat. The analyses of 20 naturally contaminated wheat samples showed DON contamination in all analyzed samples at level ranging from 30 to 2,700 μg/kg. NIV was detected in two samples at negligible toxin levels (up to 46 μg/kg). This is the first UPLC® method using immunoaffinity column cleanup for the simultaneous and sensitive determination of DON and NIV in wheat.     

Survey of 11 mycotoxins in wheat flour in Hebei province,China

A survey of 11 mycotoxins in 348 wheat flour samples marketed in Hebei province of China were analysed by liquid chromatography-tandem mass spectrometry, was carried out. The selected mycotoxins consisted of four aflatoxins (AFs: AFB₁, AFB₂, AFG₁ and AFG₂) and seven Fusarium toxins, i.e. deoxynivalenol (DON), nivalenol, 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol, zearalenone, Fusarenon-X and deoxynivalenol-3-glucoside. Results indicated that most of the wheat samples analysed were contaminated with mycotoxins. Wheat was most susceptible to DON (91.4% contamination), with a mean level of 240 μg kg^?1. On average the probable daily intake (PDI, expressed as µg kg^?1 body weight day^?1) of mycotoxins was within the provisional maximum tolerable daily intake (PMTDI, 2.0 µg kg^?1 of body weight day^?1) as set by the Joint FAO/WHO Expert Committee on Food Additives. Nevertheless, exposure assessment revealed that the maximum PDI of mycotoxins was 4.06 µg kg^?1 body weight day^?1, which was twice the PMTDI value. Thus, consistent monitoring is recommended, as to keep the contamination level under control.