Effect of gaseous ozone treatments on DON,microbial contaminants and technological parameters of wheat and semolina

Deoxynivalenol (DON) is an important mycotoxin produced by several species of Fusarium. It occurs often in wheat grain and is frequently associated with significant levels of its modified form DON-3-glucoside (DON-3-Glc). Ozone (O₃) is a powerful disinfectant and oxidant, classified as GRAS (Generally Recognised As Safe), that reacts easily with specific compounds including the mycotoxins aflatoxins, ochratoxin A, trichothecenes and zearalenone. It degrades DON in aqueous solution and can be effective for decontamination of grain. This study reports the efficacy of gaseous ozone treatments in reducing DON, DON-3-Glc, bacteria, fungi and yeasts in naturally contaminated durum wheat. A prototype was used to dispense ozone continuously and homogeneously at different concentrations and exposure time, in 2 kg aliquots of durum wheat. The optimal conditions, which do not affect chemical and rheological parameters of durum wheat, semolina and pasta, were identified (55 g O₃ h^?1 for 6 h). The measured mean reductions of DON and DON-3-Glc in ozonated wheat were 29% and 44%, respectively. Ozonation also produced a significant (p < 0.05) reduction of total count (CFU/g) of bacteria, fungi and yeasts in wheat grains.     

Deoxynivalenol suppresses circulating and splenic leukocyte subpopulations in BALB/c mice: dose response,time course and sex differences

It was hypothesized that suppression of peripheral blood leukocyte subsets were markers of exposure to dietary deoxynivalenol (DON), a Fusarium graminearum mycotoxin in grain, at 1.0 mg kg^?1 but not at lesser doses in BALB/c mice. Groups of 10 female and 10 male BALB/c mice were fed 0, 0.25, 0.5, 1.0, and 2.0 mg kg^?1 DON for 14 and 28 days. Using flow cytometry with staining for leukocyte surface markers, the percentage of CD19⁺ leukocytes (B cells) in peripheral blood was decreased in both sexes of BALB/c mice after 14 days of exposure to 1.0 or 2.0 mg kg^?1 DON, whereas exposure to DON over 28 days did not inhibit B cells compared to the control diet. The percentage of mononuclear cells in peripheral blood was decreased in female BALB/c mice fed 1 and 2 mg kg^?1 DON after 14 days compared with control diet. The percentage of CD11b⁺ leukocytes (monocytes) in peripheral blood and total CD11b⁺ splenic leukocytes were decreased only in female mice fed 1.0 and 2.0 mg kg^?1 DON after 28 days compared with control diet, which shows the greater sensitivity to DON in females compared to males. It was concluded that BALB/c mice adapted to DON exposure because peripheral blood cellular effects of DON at 14 days disappeared by 28 days with the exception of monocyte changes in females. This suggests that female sex hormones potentiate one potential marker of DON immunotoxicity in BALB/c mice.     

Effects and biotransformation of the mycotoxin deoxynivalenol in growing pigs fed with naturally contaminated pelleted grains with and without the addition of Coriobacteriaceum DSM 11798

Deoxynivalenol (DON) is one of the most prevalent Fusarium mycotoxins in grain and can cause economic losses in pig farming due to reduced feed consumption and lower weight gains. Biodetoxification of mycotoxins using bacterial strains has been a focus of research for many years. However, only a few in vivo studies have been conducted on the effectiveness of microbial detoxification of fusariotoxins. This study was therefore aimed at investigating the effect of a feed additive containing the bacterial strain Coriobacteriaceum DSM 11798 (the active ingredient in Biomin® BBSH 797) on growth performance and blood parameters, as well as uptake and metabolism of DON, in growing pigs. Forty-eight crossbred (Landrace-Yorkshire/Duroc-Duroc) weaning pigs were fed with pelleted feed made from naturally contaminated oats, with DON at four concentration levels: (1) control diet (DON < 0.2 mg kg^?1), (2) low-contaminated diet (DON = 0.92 mg kg^?1), (3) medium-contaminated diet (DON = 2.2 mg kg^?1) and (4) high-contaminated diet (DON = 5.0 mg kg^?1) and equivalent diets containing DSM 11798 as feed additive. During the first 7 days of exposure, pigs in the highest-dose group showed a 20–28% reduction in feed intake and a 24–34% reduction in weight gain compared with pigs in the control and low-dose groups. These differences were levelled out by study completion. Towards the end of the experiment, dose-dependent reductions in serum albumin, globulin and total serum protein were noted in the groups fed with DON-contaminated feed compared with the controls. The addition of DSM 11798 had no effect on the DON-related clinical effects or on the plasma concentrations of DON. The ineffectiveness of the feed additive in the present study could be a consequence of its use in pelleted feed, which might have hindered its rapid release, accessibility or detoxification efficiency in the pig’s gastrointestinal tract.     

In vivo toxicity assessment of aflatoxin B1-contaminated corn after ozone degradation

Corn is an important food and feedstuff in China and worldwide. The problems caused by aflatoxin B₁-contaminated corn (ACC) are of great concern. Our previous studies have demonstrated that ozone can effectively degrade AFB₁ in corn, prompting us to investigate the in vivo toxicity of treated ACC. In this study, 35 Kunming mice were used to assess the in vivo toxicity of ozone treated ACC. Results indicated that compared to mice fed with basal feedstuff (provided by the Shanghai SLAC Laboratory), those fed with ACC have significantly decreased mean weight as well as total protein (TP), albumin (ALB), and globulin (GLB) contents (p < 0.05). On the other hand, the liver and kidney/body weight ratio as well as the serum alanine transaminase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels significantly increased (p < 0.05). Obvious histopathological changes were found in the liver and kidney. When mice were fed with the ozone-treated ACC, no significant differences were observed in the mean weight, the liver and kidney/body weight ratio and in the major serum indexes ALT, TP, ALB, and GLB (p > 0.05). However, AST and ALP significantly increased (p < 0.05), and slight histopathological changes were found in liver tissues. This study indicated that ACC may lead to significant changes in various physiological characteristics and biochemical indexes in liver and kidney tissues, but ozone treatment of ACC could significantly reduce these changes.     

Tissue distribution and elimination of deoxynivalenol and ochratoxin A in dietary-exposed Atlantic salmon (Salmo salar)

ABSTRACT

Post-smolt Atlantic salmon (Salmo salar) were fed standard feed with added 2 or 6 mg kg^–1 pure deoxynivalenol (DON), 0.8 or 2.4 mg kg^–1 pure ochratoxin A (OTA), or no added toxins for up to 8 weeks. The experiments were performed in duplicate tanks with 25 fish each per diet group, and the feed was given for three 2-h periods per day. After 3, 6 and 8 weeks, 10 fish from each diet group were sampled. In the following hours after the last feeding at 8 weeks, toxin elimination was studied by sampling three fish per diet group at five time points. Analysis of DON and OTA in fish tissues and plasma was conducted by liquid chromatography-mass spectrometry and high-pressure liquid chromatography with fluorescence detection, respectively. DON was distributed to the liver, kidney, plasma, muscle, skin and brain, and the concentrations in liver and muscle increased significantly from 3 to 8 weeks of exposure to the high-DON diet. After the last feeding at 8 weeks, DON concentration in liver reached a maximum at 1 h and decreased thereafter with a half-life (t_1/2) of 6.2 h. DON concentration in muscle reached a maximum at 6 h and was then eliminated with a t_1/2 = 16.5 h. OTA was mainly found in liver and kidney, and the concentration in liver decreased significantly from 3 to 8 weeks in the high-OTA group. OTA was eliminated faster than DON from various tissues. By using Norwegian food consumption data and kinetic findings in this study, we predicted the human exposure to DON and OTA from fish products through carryover from the feed. Following a comparison with tolerable daily intakes, we found the risk to human health from the consumption of salmon-fed diets containing maximum recommended levels of these toxins to be negligible.     

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).     

Occurrence and risk assessment of population exposed to deoxynivalenol in foods derived from wheat flour in Brazil

Deoxynivalenol (DON) is the most important of the trichothecenes in terms of amounts and occurrence in wheat. This compound was shown to be associated with a glomerulonephropathy involving an increase of immunoglobulin A in humans. This study assessed the occurrence of DON in wheat flour and the exposure of Brazilian teenagers, adults and elderly to this mycotoxin due to intake of wheat flour-based products. DON extraction in wheat flour was carried out by solid phase extraction and the quantification was performed by ultra-high proficiency liquid chromatography with diode-array detection. A total of 77.9% of all samples were positive for DON, with concentrations ranging from 73.50 to 2794.63 µg kg^?1. The intake was calculated for the average and 90th percentile of the contamination levels of DON in foods based-wheat for teenagers, adults and elderly in Brazil, and compared with the provisional maximum tolerable daily intakes (PMTDI). Females of all age groups were exposed to DON at higher levels when compared to males in regard of consumption of breads and pastas. Teenagers were the main consumers of foods derived from wheat flour, with maximum probable daily intakes of 1.28 and 1.20 µg kg^?1 b.w. day^?1 for females and males, respectively. This population is at an increased risk of exposure to DON due to consumption of wheat flour-based foods in Brazil.     

Co-occurrence and distribution of deoxynivalenol,nivalenol and zearalenone in wheat from Brazil

Fusarium mycotoxins deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) were investigated in wheat from the 2009 and 2010 crop years. Samples (n = 745) from commercial fields were collected in four wheat producing regions (WPR) which differed in weather conditions. Analyses were performed using HPLC-DAD. Contamination with ZEN, DON and NIV occurred in 56, 86 and 50%, respectively. Also, mean concentrations were different: DON = 1046 µg kg^?1, NIV < 100 µg kg^?1 and ZEN = 82 µg kg^?1. Co-occurrence of ZEN, DON and NIV was observed in 74% of the samples from 2009 and in 12% from 2010. Wet/cold region WPR I had the highest mycotoxin concentration. Wet/moderately hot region WPR II had the lowest mycotoxin levels. Furthermore, the mean concentration of each mycotoxin was higher in samples from 2009 as compared with those from 2010. Precipitation during flowering or harvest periods may explain these results.     

Annual variation of dietary deoxynivalenol exposure during years of different Fusarium prevalence: a pilot biomonitoring study

Dietary exposure to deoxynivalenol (DON) has been reported previously in the UK, but levels were low and most individuals are well protected by the maximum permitted levels in food set by the European Commission. However, no information is available on annual fluctuation in dietary DON exposure. We hypothesised that dietary DON exposure may vary when individuals consume cereals derived from harvests with low (2011) and high (2012) Fusarium prevalence. In this pilot study, spot urine samples were collected in years 1 and 2 from 15 volunteers following their habitual diet. Urinary DON was analysed by LC-MS/MS to estimate 24-h DON excretion and daily dietary DON intake. DON was detectable in all urine samples with an average excretion of 10.08 ± 9.13 µg/24-h urine in year 1 which significantly (p = 0.005) increased to 24.84 ± 13.83 µg/24-h urine in year 2. This resulted from an estimated dietary intake of 195.94 ± 166.44 ng DON kg^–1 BW in year 1 and 518.64 ± 292.49 ng DON kg^–1 BW in year 2. Based on these estimates, the tolerable daily intake for DON was exceeded in 13% of occasions in year 2 and none in year 1. This pilot study is based on estimates of DON intake derived from urinary DON excretion. Results suggest that DON exposure varies annually and that current maximum levels might not sufficiently protect consumers during years of high Fusarium prevalence.     

Effects of oral exposure of pigs to deoxynivalenol (DON) sulfonate (DONS) as the non-toxic derivative of DON on tissue residues of DON and de-epoxy-DON and on DONS blood levels

The Fusarium toxin deoxynivalenol (DON) is of outstanding importance in pig nutrition because of its frequent occurrence in cereal grains at levels high enough to cause adverse effects such as a decrease in feed intake and impairment of the immune system. Thus, simple decontamination procedures would be useful. The present study aimed to examine the effects of wet preservation of triticale contaminated with DON and zearalenone (ZON) with sodium metabisulphite (SBS) on the treatment-related non-toxic derivative of DON (DON-sulfonate, DONS), and on ZON and its metabolites in blood and various physiological specimens of piglets. The uncontaminated control triticale (CON) and the DON-contaminated triticale (FUS) were included in the diets either untreated or SBS treated (CON-SBS, FUS-SBS) and fed to piglets for 28 days starting from weaning. The diet concentrations for DON were 0.156, 0.084, 2.312 and 0.275 mg kg^?1, for DONS were <0.05, <0.05, <0.05 and 1.841 mg kg^?1, and for ZON were <0.001, 0.006, 0.017, and 0.016 mg kg^?1 for each of CON, CON-SBS, FUS and FUS-SBS, respectively. DONS was present in the blood of piglets fed the FUS-SBS at a median concentration of 15.5 ng ml^?1 (3–67 ng ml^?1), while the median DON concentration amounted to 2 ng ml^?1 (0–5 ng ml^?1) at the same time. The median DON concentration in the blood of piglets fed the FUS diet reached a median concentration of 10.5 ng ml^?1 (5–17 ng ml^?1). Moreover, the relative differences between the DON concentrations in other physiological specimens (muscle, liver, kidney, bile and urine) in piglets fed the FUS-SBS and the FUS diet were comparable with the blood DON concentration differences. Although these differences can be taken as an indication for DONS stability after absorption and distribution further studies examining DONS in these other physiological specimens directly are necessary to substantiate this conclusion. Moreover, ZON and α-zearalenol could only be detected in bile and urine where their levels were not influenced by the SBS treatment.     

Evaluation of the TLC quantification method and occurrence of deoxynivalenol in wheat flour of southern Brazil

ABSTRACT

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R² = 0.99). A negative matrix effect (?28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2–105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.     

Efficacy of detoxification of deoxynivalenol-contaminated corn by Bacillus sp. LS100 in reducing the adverse effects of the mycotoxin on swine growth performance

Biodetoxification of mycotoxins is a novel strategy to control mycotoxicoses in animals. Bacillus sp. LS100, which transforms deoxynivalenol (DON) to a less toxic chemical de-epoxy DON (DOM-1), was evaluated for its efficacy in reducing the adverse effects of DON on swine growth performance. A feeding trial was conducted in growing pigs with four treatments: (1) corn meal without detectable DON served as control (Non-toxic Corn); (2) Fusarium-infected corn giving a toxic diet containing 5?µg DON?g^?1 (Toxic Corn); (3) Toxic Corn detoxified with Bacillus sp. LS100 giving a detoxified diet containing 5?µg DOM-1 g^?1 (LS100-De-toxic Corn); (4) Non-toxic Corn treated with Bacillus sp. LS100 serving as bacterial control (LS100-Non-toxic Corn). During 9 days of exposure to the treatments, pigs on Toxic Corn showed a significant reduction in daily feed consumption, daily weight gain and feed efficiency by 29, 48 and 29%, respectively, compared to pigs on Non-toxic Corn. These parameters of the pigs fed LS100-De-toxic Corn diet were 45, 82 and 32% greater, respectively, than those of pigs fed Toxic Corn diet, and were similar to those pigs fed Non-toxic Corn and LS100-Non-toxic Corn diets. There were no significant differences between the treatments of LS100-Non-toxic Corn and Non-toxic Corn diets, implying that the bacterial isolate might not have significantly affected nutrition and palatability of the feed or had negative effects on the pig's feeding performance. The results have proved that microbial detoxification of DON in contaminated feed can eliminate negative effects of the mycotoxin, and the pre-feeding detoxification approach may be applied in the livestock industry.     

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.     

An immunogen synthesis strategy for the development of specific anti-deoxynivalenol monoclonal antibodies

An immunogen synthesis strategy was designed to develop anti-deoxynivalenol (DON) monoclonal antibodies with low cross-reactivity against structurally similar trichothecenes. A total of eight different DON immunogens were synthesised, differing in the type and position of the linker on the DON molecule. After immunisation, antisera from mice immunised with different DON immunogens were checked for the presence of relevant antibodies. Then, both homologous and heterologous enzyme-linked immunosorbent assays (ELISAs) were performed for hybridoma screening. Finally, three monoclonal antibodies against DON and its analogues were generated. In addition, monoclonal antibody 13H1 could recognise DON and its analogues in the order of HT-2 toxin > 15-acetyldeoxynivalenol (15-ADON) > DON, with IC₅₀ ranging from 1.14 to 2.13 µg ml^–1. Another monoclonal antibody 10H10 manifested relatively close sensitivities to DON, 3-acetyldeoxynivalenol (3-ADON) and 15-ADON, with IC₅₀ values of 22, 15 and 34 ng ml^–1, respectively. Using an indirect ELISA format decreases the 10H10 sensitivity to 15-ADON with 92%. A third monoclonal antibody 2A9 showed to be very specific and sensitive to 3-ADON, with IC₅₀ of 0.38 ng ml^–1. Using both 2A9 and 10H10 monoclonal antibodies allows determining sole DON contamination.     

Occurrence of deoxynivalenol in wheat flour,instant noodle and biscuits commercialised in Brazil

A total of 134 samples, consisting of 58 wheat flour, 40 instant noodle and 36 biscuits, were analysed for the presence of deoxynivalenol (DON). The samples were obtained from retail markets of the city of São Paulo during the period 2010–2014. DON was determined by high performance liquid chromatography with ultraviolet detection and immunoaffinity sample clean-up. Method validation followed international guidelines. The LOD and LOQ were 60 and 200 µg kg^?1, respectively, considering the three different types of samples analysed. The lowest recovery found in this study was 91.8% with RSD 4.5% for instant noodles. DON was detected in 91.4%, 97.5% and 97.2% of samples wheat flour, instant noodles and biscuits, respectively, resulting in a total of 94.8% with levels ranging from LOD to 1720.0 µg kg^?1.     

Influence of temperature and pH on the degradation of deoxynivalenol (DON) in aqueous medium: comparative cytotoxicity of DON and degraded product

Deoxynivalenol (DON), a toxic fungal metabolite, is stable under different processing conditions; however, its stability in aqueous medium at different temperatures and low pH (1–2) (present in the gastrointestinal tract) has not been investigated. In the present study, DON standard was used to study the influence of temperature and pH on DON stability in aqueous medium, the characterisation of the degraded product, and the comparative toxicity profile of the degraded and the parent compound. The results suggest that standard DON was unstable at 125–250°C showing 16–100% degradation whereas DON at pH 1–3 had 30–66% degradation, with a concomitant increase in the formation of a degraded product. Further ESI-MS characterisation of the dominant precursor ion of the HPLC eluate of the DON-degraded product was found to be m/z 279, resembling the known metabolite DOM-1. The degraded product of DON was reconfirmed as DOM-1 by comparison with standard DOM-1 and both gave a similar λ_max at 208 nm. Comparative studies of both standard DOM-1 and the degraded product of DON showed no cytotoxicity up to 6400 ng ml^–1 while significant cytotoxicity was observed for DON (400 ng ml^–1). The results suggest that a highly acidic environment (pH 1–2) could be responsible for the de-epoxydation of DON leading to the formation of DOM-1.     

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.     

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).     

Mycotoxins in wheat flour and intake assessment in Shandong province of China

In the present study, the occurrence and contamination levels of eight mycotoxins were investigated in wheat flour samples (n = 359) from Shandong Province of China. Samples were determined using a multi-mycotoxin method based on isotope dilution ultrahigh performance liquid chromatography–tandem mass spectrometry. The results indicated that the most frequently found mycotoxins were deoxynivalenol (DON) (97.2%), nivalenol (40.4%) and deoxynivalenol-3-glucoside (33.4%), and mean contamination levels in positive samples were 86.7, 3.55 and 3.34 µg kg^?1, respectively. The obtained data were further used to estimate the daily intake of the local population, and indicated that wheat flour consumption contributes little to DON exposure. However, with the aim to keep the contamination levels under control and to establish a more precise evaluation of the mycotoxin burden in Shandong Province, more sample data from different harvest years and seasons are needed in the future.     

Deoxynivalenol in wheat from the Northwestern region in China

ABSTRACT

Because of global warming and changes in farming systems, Fusarium head blight has gradually spread towards high-latitude regions such as Northwestern China. A survey was conducted to assess the prevalence and concentration of deoxynivalenol (DON) in wheat harvested during 2013 from the Shaanxi, Ningxia, Gansu, and Xinjiang provinces in China. DON concentration in 181 wheat samples was analysed by high-performance liquid chromatography combined with ultraviolet detection. Of the wheat samples, 82.9% were contaminated with DON, with a mean DON concentration of 500 μg/kg. According to the Chinese standard limits for DON, 10% of the positive samples were above the maximum limit of 1000 μg/kg. Regions with higher humidity showed higher levels of DON in the wheat samples. These results show the necessity of raising awareness of DON contamination in people from Northwestern China to protect their health from the risk of exposure to DON.