A biomarker survey of urinary deoxynivalenol in China: the Shanghai Women's Health Study

Deoxynivalenol (DON) is a trichothecene mycotoxin found on wheat, maize and barley. In ecological surveys in China, DON and other trichothecenes have been implicated in acute poisoning episodes and linked with the incidence of esophageal cancer. In order to better understand exposure patterns, this pilot survey provided a combined measure of urinary un-metabolised or free DON (fD) and its glucuronide metabolite (DG) in a subset of 60 samples taken from the Shanghai Women's Health Study cohort, China. Samples were collected in 1997/1998 from women age 40-70 years. Urinary fD+DG combined was detected in 58/60 (96.7%) samples (mean 5.9 ng DON/mg creatinine; range nd-30.5); a similar frequency, and a mean level approximately half, of that previously observed for women in the UK. Wheat consumption was approximately 25% of that consumed by western diets; thus DON contamination of wheat may be higher in Shanghai than the UK. The de-epoxy metabolite of DON, a detoxification product observed in animals, was not detected, suggesting that humans may be particularly sensitive to DON due to a more restricted detoxification capacity.     

A limited survey of Fusarium mycotoxins nivalenol, deoxynivalenol and zearalenone in 1984 UK harvested wheat and barley

A limited survey for the occurrence of nivalenol (NIV), deoxynivalenol (DON) and zearalenone (ZEN) in 1984 UK-grown cereals (31 samples) have been carried out using a new procedure, which is a rapid and sensitive method for Fusarium mycotoxins. NIV, DON and ZEN were detected in 17 (55%), 20 (65%) and 4 (13%) out of 31 samples, and average levels in positive samples were 101 micrograms/kg, 31 micrograms/kg and 1 microgram/kg, respectively. Additional surveys on two wheat and eight barley samples harvested in Scotland have shown that 30%, 60% and 100% of the samples were contaminated with NIV, DON and ZEN, respectively. The contents averaged 391 micrograms/kg of NIV, 39 micrograms/kg of DON and 9 micrograms/kg of ZEN. The results of this survey show that UK-grown cereals were significantly contaminated with NIV, DON and ZEN in a similar way to that observed in Japan, Korea and China. This is the first evidence of the natural occurrence of NIV in UK cereals.     

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.     

Fusarium toxins in wheat from an area in Henan Province, PR China, with a previous human red mould intoxication episode.

Wheat samples of the 1998 and 1999 crops from Puyang, an area in Henan Province, PR China with a previous human red mould intoxication episode, were analysed for trichothecenes and zearalenone (ZEA). For the 1998 Puyang crop, deoxynivalenol (DON) was the predominant toxin detected abundantly and frequently at a level of up to 14,000 microg kg(-1) (mean 2850 microgkg(-1)) in 30 of 31 (97%) wheat samples. Among these were 21 (70%) with a DON level that exceeded the Chinese regulation of 1,000 microg kg(-1). Nivalenol (NIV) and 15-acetyl-DON (15-ADON) were also found at 578 microg kg(-1) (one sample) and 59-1,800 microg kg(-1) (mean 365 microg kg(-1), 20 samples), respectively. ZEA co-occurred in 21 samples at 9-1,400 microg kg(-1) (mean 209 microg kg(-1)). Twenty-five (89%) wheat samples from Zhumadian, a region without a history of human red mould intoxication in the same province, contained low levels of DON (53-1240, mean 223 microg kg(-1)) with seven (25%) co-contaminated with ZEA (10-217, mean 108 microg kg(-1)). All were free from 15-ADON and NIV. Significant differences in DON, 15-ADON and ZEA concentrations between both areas were found. DON (<1000 microg kg(-1)) and ZEA (5-111 microg kg(-1)) were also detected in the 1999 Puyang wheat. Proper environmental conditions for Fusarium species surviving winter combined with unusual high precipitation during wheat flowering were responsible for a high concentration of Fusarium mycotoxins in the 1998 Puyang wheat.     

Deoxynivalenol and other Fusarium toxins in wheat and rye flours on the Danish market

Information on the contamination of Danish cereals and cereal products with Fusarium toxins is limited and the last survey is from 1984/1985. In the present study, the occurrence of deoxynivalenol (DON), nivalenol (NIV), HT-2 toxin, T-2 toxin and zearalenone (ZON) was investigated in flour of common wheat, durum wheat and rye. The samples were collected from 1998 to 2001 from both mills and the retail market in Denmark. A total of 190 flour samples were analysed for DON and NIV and about 60 samples for HT-2, T-2 toxin and ZON. DON was most frequently detected with an incidence rate of 78% over all samples for all years. The contamination level varied considerably from year to year, and for wheat and rye the highest incidence and DON concentrations were found in samples from the 1998 harvest. There were regular and heavy rainfalls in Denmark during the flowering period of the crops that year, and DON was found in all samples, with mean concentrations in wheat and rye flour of 191 μg kg^-1 (n =14) and 99 μg kg^-1 (n =16), respectively. Comparison of data from each harvest year showed higher contents of DON in samples of wheat (range 20-527 μg kg^-1) than in rye (20-257 μg kg^-1). Contents of NIV, HT-2 toxin and ZON in samples of wheat and rye were generally low, and even in positive samples the contents were close to the detection limit of the methods. The T-2 toxin was detected in only a few of the wheat samples and in low amounts. However, the toxin was found in about 50% of the rye samples collected during 1998-2000, with a mean content of 49 μg kg^-1 (n =25). Durum wheat flour showed the highest DON contamination level, and all samples (n =33) collected during 2000 and 2001 contained DON with means and medians above 1100 μg kg^-1. Over 70% of the samples contained more than 500 μg kg^-1 DON, and the highest observed concentration was 2591 μg kg^-1. The concentration of T-2 toxin in durum wheat flour was also high with five of the 10 analysed samples containing more than 100 g kg^-1.     

脱氧雪腐镰刀菌烯醇解毒酶研究进展

脱氧雪腐镰刀菌烯醇（Deoxynivalenol, DON）是镰刀菌属（Fusariums spp.）产生的剧毒次级代谢产物,主要污染小麦、玉米等粮食及其制品,导致了严重的食品安全风险。目前生物酶法去除DON的技术研究,展现出良好的应用前景。综述了国内外关于DON生物转化的生物酶类型、降解机制、产物结构特征、解毒酶挖掘策略,以及解毒酶分子改造等研究现状,并对人工智能应用于真菌毒素解毒酶的相关研究进行了展望,以期为食品和饲料中DON的生物脱毒技术的研发提供参考。     

Occurrence of deoxynivalenol in an elderly cohort in the UK: a biomonitoring approach

ABSTRACT

Deoxynivalenol (DON) is a Fusarium toxin, to which humans are frequently exposed via diet. Although the elderly are speculated to be sensitive to the toxic effects of DON as a result of age-related conditions, disease and altered DON metabolism, there is lack of available data on DON biomarkers in this age group. This study characterised urinary DON concentrations and its metabolites in elderly aged ≥65years (n = 20) residing in Hull, UK. Morning urinary specimens were collected over two consecutive days together with food records to assess dietary intake over a 24h-period prior to each urinary collection. Free DON (un-metabolised), total DON (sum of free DON and DON-glucuronides or DON-GlcA) and de-epoxy deoxynivalenol (DOM-1) were analysed using a validated LC-MS/MS methodology. Total DON above the limit of quantification 0.25 ng/mL was detected in the urine from 90% of elderly men and women on both days. Mean total DON concentrations on day 1 were not different from those on day 2 (elderly men, day 1: 22.2 ± 26.3 ng/mg creatinine (creat), day 2: 28.0 ± 34.4 ng/mg creat, p = 0.95; elderly women, day 1: 22.4 ± 14.6 ng/mg creat, day 2: 29.1 ± 22.8 ng/mg creat, p = 0.58). Free DON and DON-GlcA were detected in 60–70% and 90% of total urine samples, respectively. DOM-1 was absent from all samples; the LoQ for DOM-1 was 0.50 ng/mL. Estimated dietary intake of DON suggested that 10% of the elderly exceeded the maximum provisional tolerable daily intake for DON. In this single-site, UK-based cohort, elderly were frequently exposed to DON, although mean total DON concentrations were reported at moderate levels. Future larger studies are required to investigate DON exposure in elderly from different regions of the UK, but also from different counties worldwide.     

A survey on the occurrence of Fusarium mycotoxins in Bavarian cereals from the 1987 harvest

Bavarian cereals and wheat flour from the 1987 harvest were analysed for nivalenol (NIV) and deoxynivalenol (DON) using high performance liquid chromatography (HPLC) and for T-2 toxin and zearalenone (ZEA) by enzyme-linked-immunosorbent assay (ELISA). The study included 190 field samples of wheat, barley, rye and oat with visibly damaged ears, 45 samples of wheat intended for feed production and two series of wheat flour (type 550) and whole wheat flour collected in October 1987 and June 1988. The field samples examined showed a high DON contamination of wheat (87%) with an average of 3.96 mg/kg and a maximum of 43.8 mg/kg. Mean levels between 0.33 mg/kg and 0.27 mg/kg DON could be detected in barley, rye and oat. Of the wheat samples, 58% contained ZEA with a maximum of 1.560 mg/kg. The highest levels of ZEA were detected in samples which also showed high concentrations of DON. The NIV and T-2 toxin levels were comparatively low. Thirty percent of the samples showed NIV concentrations between 0.04 mg/kg and 0.29 mg/kg and 38% contained between 0.005 and 0.60 mg/kg of T-2. In the wheat samples for feed production, only DON was detected with an average of 0.190 mg/kg and a maximum of 0.75 mg/kg. The highest DON levels (0.58 mg/kg) from October 1987 were found in the wheat flour samples which were lower than the highest DON concentration (3.24 mg/kg) detected in the samples collected during June 1988. This fact was probably due to a substantial amount of non-contaminated wheat from 1986. The toxin concentrations in the whole wheat flour were not higher than in the type 550 flour.(ABSTRACT TRUNCATED AT 250 WORDS)     

Deoxynivalenol exposure assessment in a cohort of pregnant women from Bradford, UK

Deoxynivalenol (DON) is a ubiquitous contaminant of cereal crops in temperate regions of the world. It causes growth faltering and immune suppression in animals. Limited information is available on DON exposure in UK subpopulations. The objective of this study was to provide DON exposure assessment in a subset of pregnant women scheduled for an elective caesarean in a large multi-ethnic mother/infant birth cohort from Bradford, UK. Women aged 16-44 years (n = 85) provided a urine sample for DON analysis in the last trimester of pregnancy, and concurrently completed a food-frequency questionnaire (FFQ). The urinary DON biomarker was detected in all measured samples (geometric mean (GM)?= 10.3 ng DON mg(-1) creatinine, range = 0.5-116.7 ng mg(-1)). Levels were higher in women classified as South Asian in origin (GM: 15.2 ng mg(-1); 95% CI = 10.7-21.5 ng mg(-1)) compared with non-South Asians (GM = 8.6 ng mg(-1); 95% CI = 6.6-11.8 ng mg(-1)), p = 0.02). Estimated DON intake from FFQ data and typical levels of DON contamination of food suggest that this was mainly due to higher levels of exposure from bread, particularly daily intake of DON from chapattis in South Asians (estimated mean = 2.4 μg day(-1); 95% CI = 1.2, 3.7 μg day(-1)) compared with non-South Asians (estimated mean = 0.2 μg day(-1); 95% CI = 0-0.4 μg day(-1)), p < 0.001. This is the first biomarker demonstration of DON exposure in pregnant women, and several urinary DON levels were the highest ever recorded in any study. A larger survey within this birth cohort is warranted to investigate any potential risk to mothers and their babies, from DON exposure during pregnancy.     

酶联免疫吸附法测定小麦中脱氧雪腐镰刀菌烯醇

目的 建立小麦中脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)含量测定的酶联免疫吸附(ELISA)分析方法。方法 选取山东省4地区小麦样品80份, 用不同溶剂对小麦中的DON进行提取后,构建小麦中DON的ELISA检测方法, 根据国家标准对检测结果进行评价。结果 选用84%的乙腈水溶液作为提取溶剂, 其平均回收率可达100.2%, 较为理想。该ELISA方法检测小麦中DON, 线性范围是5~5000 ng/g, 回归方程Y= 0.0419X 0.0222, 相关系数r=0.9868, 样品中DON含量为5.27~3639.38 ng/g , 中位数为79.25 ng/g, 在所检测的80份样品中, 有4份超出了国家规定的上限标准(1000 ng/g), 76份符合国家规定, 合格率为95％。结论 该方法灵敏、快捷, 适用于小麦中脱氧雪腐镰刀菌烯醇的检测。     

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.     

Effects of Fusarium toxin-contaminated wheat and feed intake level on the biotransformation and carry-over of deoxynivalenol in dairy cows

An experiment was carried out to examine the effects of feeding Fusarium toxin-contaminated wheat (8.21 mg deoxynivalenol (DON) and 0.09 mg zearalenone (ZON) per kg dry matter) at different feed intake levels on the biotransformation and carry-over of DON in dairy cows. For this purpose, 14 ruminal and duodenal fistulated dairy cows were fed a diet containing 60% concentrate with a wheat portion of 55% (Fusarium toxin-contaminated wheat (mycotoxin period) or control wheat (control period)) and the ration was completed with maize- and grass silage (50 : 50) on a dry matter basis. Daily DON intakes ranged from 16.6 to 75.6 mg in the mycotoxin period at dry matter intakes of 5.6-20.5 kg. DON was almost completely biotransformed to de-epoxy DON (94-99%) independent of the DON/feed intake, and the flow of DON and de-epoxy DON at the duodenum related to DON intake ranged from 12 to 77% when the Fusarium toxin-contaminated wheat was fed. In the serum samples, de-epoxy DON was detected in the range of 4-28 ng ml^-1 in the mycotoxin period, while concentrations of DON were all below the detection limit. The daily excretion of DON and de-epoxy DON in the milk of cows fed the contaminated wheat varied between 1 and 10 µg and between 14 and 104 µg, respectively. The total carry-over rates as the ratio between the daily excretion of DON and de-epoxy DON into milk and DON intake were in the ranges of 0.0001-0.0002 and 0.0004-0.0024, respectively. Total carry-over rates of DON as DON and de-epoxy DON into the milk increased significantly with increasing milk yield. In the urine samples, de-epoxy DON was the predominant substance as compared with DON with a portion of the total DON plus de-epoxy DON concentration to 96% when the Fusarium toxin-contaminated wheat was fed, whereas the total residues of DON plus de-epoxy DON in faeces ranged between 2 and 18% of DON intake in the mycotoxin period. The degree of glucuronidation of de-epoxy DON was found to be approximately 100% in serum. From 33 to 80% of DON and from 73 to 92% of de-epoxy DON, and from 21 to 92% of DON and from 86 to 100% of de-epoxy DON were glucuronidated in the milk and urine, respectively. It is concluded that DON is very rapidly biotransformed to de-epoxy DON in the rumen and only negligible amounts of DON and de-epoxy DON were transmitted into the milk within the range of 5.6-20.5 kg day^-1 dry matter intake and milk yields (fat corrected milk) between 10 and 42 kg day^-1.     

Fusarium mycotoxin content of UK organic and conventional wheat

Each year (2001–2005), 300 samples of wheat from fields of known agronomy were analysed for ten trichothecenes by gas chromatography-mass spectrometry (GC/MS) including deoxynivalenol (DON), nivalenol, 3-acetyl-DON, 15-acetyl-DON, fusarenone X, T2 toxin, HT2 toxin, diacetoxyscirpenol, neosolaniol and T-2 triol and zearalenone by high-performance liquid chromatography (HPLC). Of the eleven mycotoxins analysed from 1624 harvest samples of wheat, only eight were detected, and of these only five–deoxynivalenol, 15-acetyl-DON, nivalenol, HT-2 and zearalenone–were detected above 100 µg kg^?1. DON was the most frequently detected Fusarium mycotoxin, present above the limit of quantification (10 µg kg^?1) in 86% of samples, and was usually present at the highest concentration. The percentage of samples that would have exceeded the recently introduced legal limits varied between 0.4% and 11.3% over the five-year period. There was a good correlation between DON and zearalenone concentrations, although the relative concentration of DON and zearalenone fluctuated between years. Year and region had a significant effect on all mycotoxins analysed. There was no significant difference in the DON concentration of organic and conventional samples. There was also no significant difference in the concentration of zearalenone between organic and conventional samples, however organic samples did have a significantly lower concentration of HT2 and T2. Overall, the risk of UK wheat exceeding the newly introduced legal limits for Fusarium mycotoxins in cereals intended for human consumption is low, but the percentage of samples above these limits will fluctuate between years.     

Residues of deoxynivalenol (DON) in pig tissue after feeding mash or pellet diets containing low concentrations

Residues of deoxynivalenol (DON) and its metabolite de-epoxy-DON (DOM) were analyzed in specimens of pigs fed diets containing 0, 25, and 50% contaminated wheat (2.5 mg DON/kg) fed as mash or pellets over the final growing period of 11 wk. Median DON concentrations decreased from bile > kidney > serum > liver = muscle, while DOM was only detected in bile and kidney. Maximum carry over rates were 0.0319 for kidney, 0.0064 for liver, and 0.0043 for muscle, demonstrating that the contribution of animal derived food to the consumers' exposure is very low. The high interindividual variation of DON concentrations in all analyzed specimen of pigs fed diets containing similar concentrations of DON does not allow a diagnostic differentiation of animals fed diets containing DON concentrations of approximately 61% of the guidance level of 0.9 mg DON/kg, and those fed diets containing 137% of this concentration. The different feed forms did not affect residue concentrations in any of the investigated specimens.     

Impact of agronomic factors on fusarium mycotoxins in harvested wheat

ABSTRACT

The aim of this study was to model fusarium mycotoxins against agronomic factors in order to identify those that have the greatest impact on mycotoxin levels in harvested wheat. To achieve this, fusarium mycotoxins levels were monitored, and associated agronomic data collected, in approximately 150 English wheat fields/year between 2006 and 2013. Results showed large seasonal variation in fusarium mycotoxin levels, with high levels in 2008 (13% and 29% exceeding legal limit for unprocessed soft wheat intended for human consumption for deoxynivalenol (DON) and zearalenone (ZON), respectively) and 2012 (10% and 15% exceeding legal limit for unprocessed soft wheat intended for human consumption for DON and ZON, respectively) and low levels in 2006 and 2011 (no samples exceeding legal limits for unprocessed soft wheat intended for human consumption for DON or ZON). Analysis of agronomic factors identified previous crop, cultivation and variety as the greatest risk factors. The greatest risk of mycotoxin development in grain was following maize as a previous crop and minimum tillage. The combined effect of these factors gave respective average DON and ZON levels 20 and 14 times higher than other previous crop and cultivation combinations. A newly quantified risk factor was harvest date. A 1-month delay in harvest resulted in a 10 and 25 times greater mean DON and ZON concentration, respectively, when compared to crops harvested around the long-term regional average harvest date. These results highlight the highly seasonal variation in fusarium mycotoxins in wheat and the agronomic factors that should be avoided to minimise fusarium mycotoxin levels in harvested wheat.     

A survey on the occurrence of Fusarium mycotoxins in Bavarian cereals from the 1987 harvest

Summary Bavarian cereals and wheat flour from the 1987 harvest were analysed for nivalenol (NIV) and deoxynivalenol (DON) using high performance liquid chromatography (HPLC) and for T-2 toxin and zearalenone (ZEA) by enzyme-linked-immunosorbent as say (ELISA). The study included 190 field samples of wheat, barley, rye and oat with visibly damaged ears, 45 samples of wheat intended for feed production and two series of wheat flour (type 550) and whole wheat flour collected in October 1987 and June 1988. The field samples examined showed a high DON contamination of wheat (87%) with an average of 3.96 mg/kg and a maximum of 43.8 mg/kg. Mean levels between 0.33 mg/kg and 0.27 mg/kg DON could be detected in barley, rye and oat. Of the wheat samples, 58% contained ZEA with a maximum of 1.560 mg/kg. The highest levels of ZEA were detected in samples which also showed high concentrations of DON. The NIV and T-2 toxin levels were comparatively low. Thirty percent of the samples showed NIV concentrations between 0.04 mg/kg and 0.29 mg/kg and 38% contained between 0.005 and 0.60 mg/kg of T-2. In the wheat samples for feed production, only DON was detected with an average of 0.190 mg/kg and a maximum of 0.75 mg/kg. The highest DON levels (0.58 mg/kg) from October 1987 were found in the wheat flour samples which were lower than the highest DON concentration (3.24 mg/kg) detected in the samples collected during June 1988. This fact was probably due to a substantial amount of non-contaminated wheat from 1986. The toxin concentrations in the whole wheat flour were not higher than in the type 550 flour. The regional distribution of the mean DON concentrations showed the highest levels in Middle and Lower-Franconia.

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Vorkommen von Fusarium Mykotoxinen in bayerischem Getreide der Ernte 1987

Zusammenfassung Cerealien und Weizenmehle der bayerischen Ernte 1987 wurden mittels hochauflösender Flüssigchromatographie (HPLC) auf Nivalenol (NIV) und Deoxynivalenol (DON) Bowie mit Enzymimmunoassay auf T-2 Toxin und Zearalenon (ZEA) analysiert. Die Untersuchungen umfaßten 190 Feldproben von Weizen, Gerste, Roggen und Hafer, die alle optisch erkennbaren Fusarienbefall aufwiesen, 45 Futterweizenproben Bowie zwei Probenserien von Weizenmehlen der Type 550 und Vollkornweizenmehlen, die im October 1987 und im Juni 1988 gezogenwurden. — Die Untersuchungen der Feldproben ergaben eine hohe DON-Kontamination des Weizens (87%) mit einem durchschnittlichen Gehalt von 3,96 mg/kg und einem Maximalgehalt von 43,8 mg/kg. In Gerste, Roggen und Hafer konnten durchschnittlich zwischen 0,33 mg/kg und 0,27 mg/kg DON-nachgewiesen werden. 58% der Winterweizenproben wiesen Zearalenon mit einem Maximalgehalt von 1,56 mg/kg auf. Die höchsten ZEA-Werte wurden in Proben ermittelt, die gleichzeitig einen hohen DON-Gehalt aufwiesen. Die Konzentrationen von NIV und T-2 Toxin waren vergleichsweise niedrig. 30% der Proben hatten NIV-Gehalte zwischen 0,04 mg/kg und 0,29 mg/kg und 38% enthielten T-2 Toxin zwischen 0,005 mg/kg und 0,06 mg/kg. In den Futterweizenproben konnte DON als einziges Toxin mit einem Gehalt von durchschnittlich 0,19 mg/kg und maximal 0,75 mg/kg festgestellt werden. Die Weizenmehle, die im October 1987 gezogen wurden, wiesen maximal 0,58 mg/kg DON auf. Die Gehalte lagen damit medriger als die der Mehlproben vom Juni 1988, die maximal 3,24 mg/kg und durchschnittlich 0,26 mg/kg DON enthielten. Dieser Sachverhalt könnte auf Anteile von nicht kontaminiertem Weizen der Ernte 86 an den im October gezogenen Mehlproben zurückgeführt werden. Die Toxingehalte der Vollkornmehle waren nicht höher als die der Weizenmehle der Type 550. Die höchsten Durchschnittsgehalte von DON wurden in Mittel- und Unterfranken festgestellt.

     

Fusarium mycotoxin content of UK organic and conventional barley

Each year (2002–2005), approximately 100 samples of barley from fields of known agronomy were analysed for ten trichothecenes by gas chromatography-mass spectrometry (GC/MS) including deoxynivalenol (DON), nivalenol, 3-acetyl DON, 15-acetyl DON, fusarenone X, T-2 toxin (T2), HT-2 toxin (HT2), diacetoxyscirpenol, neosolaniol, and T-2 triol. Samples were also analysed for moniliformin and zearalenone by high-performance liquid chromatography (HPLC). Of the ten trichothecenes analysed from 446 harvest samples of barley, only two, diacetoxyscirpenol and neosolaniol, were not detected. The concentrations of type A trichothecenes were similar to those that occurred in wheat over the same period, whilst those of type B trichothecenes were markedly lower. Deoxynivalenol was the most frequently detected Fusarium mycotoxin, present above the limit of quantification (10 µg kg^?1) in 57% of samples, and was usually present at the highest concentration. A single sample (0.2%) exceeded the legal limit for DON in unprocessed barley over the 4-year period. Moniliformin and zearalenone were both rarely detected (2% of samples greater than 10 µg kg^?1 for both toxins) with maximum concentrations of 45 and 44 µg kg^?1, respectively. Year and region had a significant effect on DON and HT2 + T2, but there was no significant difference in the concentration of these mycotoxins between organic and conventional samples. Overall, the risk of UK barley exceeding the newly introduced legal limits for Fusarium mycotoxins in cereals intended for human consumption is very low, but the percentage of samples above these limits will fluctuate between years.     

No carry over of unmetabolised deoxynivalenol in milk of dairy cows fed high concentrate proportions

To examine the carry over of deoxynivalenol (DON) and its metabolite de-epoxy DON (DOM-1) in milk, lactating German Holstein cows (n = 13) were fed an isoenergetic total mixed ration in Period 1 with 50% concentrates and 5.3 mg DON/kg dry matter (DM) over 11 wk and were compared with control cows (n = 14). In Period 2 (18 wk), an elevated concentrate proportion was compared to a low concentrate ration by dividing the cows into four Groups (n = 8): Control-30 (30% concentrates), Myco-30 (30% concentrates, 4.4 mg DON/kg DM), Control-60 (60% concentrates) and Myco-60 (60% concentrates, 4.6 mg DON/kg DM). Taken both periods together, no unmetabolised DON was detected in milk samples using the HPLC-UV method. DOM-1 concentrations ranged between below the LOD and 3.2 microg/kg milk in mycotoxin fed cows, while control cows did not excrete any measurable amounts of DOM-1. Regarding the concentrate effects, the carry over of DON as DOM-1 in milk was negligible (between 0.0001 and 0.0011) but significantly higher in Group Myco-30 than in Group Myco-60. This effect may result from an altered bioavailability of DON from maize silage which made up a higher proportion of the daily ration.     

Utilization of highly deoxynivalenol-contaminated wheat via extrusion processing

Deoxynivalenol (DON) is a toxic natural metabolite produced by Fusarium graminearum. In this study we investigated the effects of sodium bisulfite and extrusion cooking under high temperature and pressure on DON levels in wheat grain and mill fractions. Samples of highly naturally DON-contaminated soft winter wheat were soaked for 1 h in water or aqueous sodium bisulfite (SB) solutions (0.5, 1.5, 2.5, or 5% SO2 equivalent) and extruded. The soaking treatment with SB solution (5% SO2 equivalent) lowered DON from 7.3 microg/g to 0.8 microg/g without extrusion and to 0.3 microg/g with an extrusion process. When the contaminated kernels were tempered with water or SB solutions (5 or 10% SO2 equivalent) and milled, the flour samples, as expected, showed lower levels of DON (from 7.3 to 3.1 microg/g). Extrusion of milled flour and whole meal samples, both obtained from SB-tempered wheat, did not change DON levels significantly under the studied extrusion conditions as compared to the nonextruded milled flour and whole meal samples. However, the extrusion process can be utilized to remove moisture and/or odor of chemicals used in the soaking solutions and to produce potentially useful extruded products.     

Deoxynivalenol exposure assessment in a cohort of pregnant women from Bradford,UK

Deoxynivalenol (DON) is a ubiquitous contaminant of cereal crops in temperate regions of the world. It causes growth faltering and immune suppression in animals. Limited information is available on DON exposure in UK subpopulations. The objective of this study was to provide DON exposure assessment in a subset of pregnant women scheduled for an elective caesarean in a large multi-ethnic mother/infant birth cohort from Bradford, UK. Women aged 16–44 years (n?=?85) provided a urine sample for DON analysis in the last trimester of pregnancy, and concurrently completed a food-frequency questionnaire (FFQ). The urinary DON biomarker was detected in all measured samples (geometric mean (GM)?=?10.3?ng?DON?mg^?1 creatinine, range?=?0.5?116.7?ng?mg^?1). Levels were higher in women classified as South Asian in origin (GM: 15.2?ng?mg^?1; 95% CI?=?10.7?21.5?ng?mg^?1) compared with non-South Asians (GM?=?8.6?ng?mg^?1; 95% CI?=?6.6?11.8?ng?mg^?1), p?=?0.02). Estimated DON intake from FFQ data and typical levels of DON contamination of food suggest that this was mainly due to higher levels of exposure from bread, particularly daily intake of DON from chapattis in South Asians (estimated mean?=?2.4?µg?day^?1; 95% CI?=?1.2, 3.7?µg?day^?1) compared with non-South Asians (estimated mean?=?0.2?µg?day^?1; 95% CI?=?0?0.4?µg?day^?1), p?<?0.001. This is the first biomarker demonstration of DON exposure in pregnant women, and several urinary DON levels were the highest ever recorded in any study. A larger survey within this birth cohort is warranted to investigate any potential risk to mothers and their babies, from DON exposure during pregnancy.