Development of a multicomponent method for Fusarium toxins using LC-MS/MS and its application during a survey for the content of T-2 toxin and deoxynivalenol in various feed and food samples.

A reliable, sensitive and selective method was developed to determine different Fusarium mycotoxins (trichothecenes Type A and B, zearalenone) simultaneously in cereals and cereal-based samples using liquid chromatography with tandem mass spectrometry (LC-ESI-MS/MS). Sample preparation is based on a standard solvent extraction step followed by two different kinds of solid-phase clean-up procedures: using a multifunctional MycoSep material for trichothecenes and zearalenone. The average recoveries for trichothecenes ranged from 65% for nivalenol (NIV) up to 96% for deoxynivalenol (DON) and 89% for zearalenone (ZON). The limit of quantification varied between 0.02 and 10 ppb for each substance. In addition, a screening survey with 685 samples was carried out to compare contents of T-2 toxin and deoxynivalenol and to investigate potential coherence in contamination pattern.     

Simple and high-throughput method for the multimycotoxin analysis in cereals and related foods by ultra-high performance liquid chromatography/tandem mass spectrometry

A rapid, reliable and sensitive method was developed to determine 12 mycotoxins (deoxynivalenol, aflatoxins B1, B2, G1, G2 and M1, fumonisins B1 and B2, ochratoxin A, HT-2 and T-2 toxin and zearalenone) simultaneously in maize, walnuts, biscuits and breakfast cereals. The method is based on a single extraction step using acetonitrile/water mixture (80/20 v/v) followed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS). The selectivity of the MS/MS detection allowed the elimination of further clean up steps. Extraction, chromatographic and detection conditions were optimised in order to increase sample throughput and sensitivity. Matrix-matched calibration was used for quantification and recoveries of the extraction process ranged from 70.0% and 108.4%, with relative standard deviations lower than 25% in all the cases, when samples were fortified at 5 and 50 μg/kg. Limits of detection ranged from 0.01 to 2.1 μg/kg and limits of quantification ranged from 0.03 to 6.30 μg/kg, which were always below the tolerance levels of mycotoxins set by European Union in the matrices evaluated. Several samples were analysed and aflatoxins B1, B2, G1, G2 and T-2 toxin were detected in one maize sample, with concentrations lower than 6.0 μg/kg and deoxynivalenol was detected in a breakfast cereal at 42.1 μg/kg.     

Determination of mycotoxins in cereals by liquid chromatography tandem mass spectrometry

A liquid chromatography tandem mass spectrometry (LC–MS/MS) method is described for simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB₁ and FB₂), T2 and HT2-toxin in cereals. One-step extraction using solvent mixtures of acetonitrile:water:acetic acid (79:20:1) without any clean-up was employed for extraction of these mycotoxins from cereals. The mean recoveries of mycotoxins in spiked cereals ranged from 76.8% to 108.4%. Limits of detection (LOD) and quantification (LOQ) ranged 0.01–20 and 0.02–40 ng/g, respectively. The developed method has been applied for the determination of mycotoxins in 100 cereal samples collected from Malaysian markets. A total of 77 cereal samples (77%) contaminated with at least one of these mycotoxins. Occurrence of mycotoxins in commercial cereal samples were 70%, 40%, 25%, 36%, 19%, 13%, 16, and 16% for aflatoxins, OTA, ZEA, DON, FB₁, FB₂, T2 and HT2-toxin, respectively. The results demonstrated that the procedure was suitable for the determination of mycotoxins in cereals and could be implemented for the routine analysis.     

Multiresidue method for determination of 88 pesticides in berry fruits using solid-phase extraction and gas chromatography–mass spectrometry: Determination of 88 pesticides in berries using SPE and GC–MS

A method using solid phase extraction (SPE) cleanup followed by gas chromatography–mass spectrometry (GC–MS) has been established for quantitative determination of 88 pesticide residues in berry fruits including raspberry, strawberry, blueberry and grape. Based on an appraisal of the characteristics of GC–MS, validation experiments were conducted for 88 pesticides. In the method, solid-phase extraction was carried out using Envi-Carb cartridge coupled with NH₂-LC cartridge with acetonitrile–toluene (3:1, v/v) as the eluted solvent. In the linear range of each pesticide, the correlation coefficient was R² ? 0.99. At the low, medium and high three fortification levels of 0.05–0.5 mg kg⁻¹, recoveries fell within 63–137%. The relative standard deviation was between 1% and 19% for all 88 pesticides. Low limits of detection (0.006–0.05 mg kg⁻¹) and quantification (0.02–0.15 mg kg⁻¹) were readily achieved with this method for all tested pesticides.     

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).     

Further data on the levels of emerging Fusarium mycotoxins enniatins (A,A1, B,B1), beauvericin and fusaproliferin in breakfast and infant cereals from Morocco

Sixty-eight samples of cereals products, including breakfast cereals (n = 48) and infant cereals (n = 20), purchased from supermarkets and pharmacies in Rabat-Salé area from Morocco were analysed for the determination of six emerging mycotoxins: four enniatins ENs (ENA, ENA1, ENB and ENB1), beauvericin (BEA) and fusaproliferin (FUS). Samples were extracted with a mixture of acetonitrile:water (85:15, v/v), using an Ultra-Turrax® homogeniser. Mycotoxins were then identified and quantified by liquid chromatography (LC) with diode array detection (DAD). Positive samples were confirmed by LC–MS/MS.     

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).     

Occurrence of deoxynivalenol and T-2 toxin in bread and pasta commercialised in Spain

Deoxynivalenol and T-2 toxin were extracted from wheat-based bread (n = 75) and pasta (n = 75) samples using a mixture of acetonitrile:water (86:14 v/v); for analysis, gas chromatography/mass spectrometry after derivatisation with trifluoroacetic anhydride was utilised. The recovery of deoxynivalenol and T-2 toxin from both food matrixes ranged from 90.1 to 94.0%. The occurrence of these mycotoxins in bread was 28.0% and 2.6% for deoxynivalenol and T-2 toxin, respectively, whereas in pasta, the occurrence of both mycotoxins was higher, varying from 9.3 to 62.7%. The mean content of deoxynivalenol (42.5 μg/kg) in bread was lower than the content of T-2 toxin (68.37 μg/kg), while in pasta the content of deoxynivalenol (137.1 μg/kg) was superior. The estimated daily intake of deoxynivalenol and T-2 toxin from the consumption of these products represents 8.4% and 0.2% of the tolerable daily intake, respectively. These results back up the necessity to take a vigilant attitude in order to prevent human intake of trichothecenes. This information is necessary and of high priority in order to protect the consumer’s health from the risk of exposure to these toxins.     

Occurrence of Fusarium species and trichothecenes in Nigerian maize

A total of 180 maize samples meant for human consumption from four maize-producing states of southwestern Nigeria were screened for twelve major Fusarium mycotoxins (trichothecenes). Mycological examination of the samples showed that Fusarium verticillioides was the most commonly isolated fungi (71%), followed by F. sporotrichioides (64%), F. graminearum (32%), F. pallidoroseum (15%), F. compactum (12%), F. equiseti (9%), F. acuminatum (8%), F. subglutinans (4%) and F. oxysporum (1%). The trichothecenes include deoxynivalenol (DON), 3, mono-acetyldeoxynivalenol (3-AcDON), 15, mono-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), HT-2 toxin (HT-2), neosolaniol (NEO), T-2 toxin (T-2), T-2 tetraol and T-2 triol, diacetoxyscirpenol (DAS), MAS-monoacetoxyscirpenol (MAS) and fusarenone-X. Quantification was by high performance liquid chromatography coupled with mass spectroscopy (HPLC/MS); the detection limits for each of the mycotoxins varied between 20 and 200 microg kg(-1). Sixty six samples (36.3%) were contaminated with trichothecenes, DON (mean: 226.2 microg kg(-1); range: 9.6-745.1 microg kg(-1)), 3-AcDON (mean: 17.3 microg kg(-1); range: 0.7-72.4 microg kg(-1)) and DAS (mean: 16.0 microg kg(-1); range: 1.0-51.0 microg kg(-1)) were detected in 22%, 17% and 9% of total samples respectively. There were no 15-AcDON, NIV, HT-2, NEO, T-2, T-2 tetraol, T-2 triol, MAS and fusarenone-X detected. This is the first comprehensive report about the natural occurrence of DON, AcDON and DAS in maize for direct human consumption in Nigeria.     

Determination of type B trichothecenes and macrocyclic lactone mycotoxins in field contaminated maize

A sensitive, reliable liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for determining some commonly found mycotoxins produced by Fusarium strains in maize was evaluated and applied to field samples. The selected substances were: trichothecenes B (nivalenol, deoxynivalenol, fusarenon X, 3- and 15-acetyldeoxynivalenol) and some macrocyclic lactones (zearalenone, α- and β-zearalenol, zearalanone, α- and β-zearalanol). Analytes were extracted from a 1 g sample by homogenization with acetonitrile/water (75:25, v/v, 25 mL final volume). 5 mL of crude extracts was cleaned-up on Carbograph-4 cartridges. Two fractions were obtained and were analyzed by HPLC-electrospray ionization (ESI) in negative mode. Recoveries for spiked maize samples were in the range 79–106% and method detection limits (MDLs) were ⩽6 ng/g for all compounds, except fusarenon X (12 ng/g). 25 random maize samples were analyzed both by the ELISA-based methods specific for deoxynivalenol and zearalenone and by this method for trichothecenes B and macrocyclic lactones. Results were comparable for zearalenone (R² = 0.982), but disagreed for deoxynivalenol. Finally, a total of 78 freshly harvested maize samples, collected from central and northern Italy during 2002, and divided in two different experiments, were analyzed by the developed method. Data show that there exists a phenomenon of random contamination from the target fusariotoxins just before harvest and an increase of trichothecene B and zearalenone abundance on field crop possibly related to damp climate, temperature range and delayed harvest period. Deoxynivalenol was the most abundant (up to 3430 ng/g) and frequent mycotoxin (40%) detected, followed by acetyldeoxynivalenol. Derivatives of zearalenone were present in traces and β-zearalanol was never found.     

Mycotoxins produced by Fusarium genus in maize: determination by screening and confirmatory methods based on liquid chromatography tandem mass spectrometry

A confirmatory method for fusariotoxin analysis in maize meal, based on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS), was developed, and compared with a previously published screening method, based on the same technique. By eluting selectively from a Carbograph-4 clean-up cartridge trichothecenes, fumonisins and macrocyclic lactones, and optimizing LC–MS/MS conditions for every chemical class, a sensitive and reliable determination was performed. Method quantification limits for confirmatory and screening methods were in the range 0.001–0.019 mg/kg and 0.003–0.125 mg/kg, respectively.     

Migration of mycotoxins into rice starchy endosperm during the parboiling process

Considering the occurrence of rice contamination by mycotoxins and the increase in rice consumption, the present work had the objective of assessing the migration of mycotoxins into the starchy endosperm during the parboiling process, as to propose conditions that provide lower contamination levels. The newly harvested rice grain sample was examined for the natural occurrence of mycotoxins (aflatoxin B₁, aflatoxin B₂, deoxynivalenol, ochratoxin A, and zearalenone); only the presence of aflatoxin B₁ was found (17 ng/g). The samples were then artificially contaminated with deoxynivalenol and zearalenone, and the parboiling process was conducted according to a 2³ factorial planning with central point, having as variables the contamination level deoxynivalenol 720, 1440, and 2160 ng/g, and zearalenone 476, 952, and 1428 ng/g the soaking time (4, 5, and 6 h) and autoclave time (15, 22.5, and 30 min). Mycotoxins aflatoxin B₁ (AFA B₁), deoxynivalenol (DON), and zearalenone (ZEA) were confirmed and determined through gas chromatography. Findings showed a lower migration trend for AFA B₁ under 6 h of soaking and 30 min of autoclaving, for DON under 6 h of soaking regardless of the autoclaving time, and for ZEA under 4 h of soaking and 15 min of autoclaving. This information can contribute to the choice of process parameters that limit the migration of these mycotoxins if they happen in the raw material.     

Identification of irradiated meats by determining o- and m-tyrosine as markers

To identify the irradiated meats, various parameters that affect extraction efficiency of tyrosine positional isomers were evaluated. The optimum procedure employed simple extraction by 0.1% formic acid and protein precipitation by acetone. Baseline separation for the extract was carried out on LC–fluorescence detection (FLD) and LC–tandem mass spectrometry (MS/MS). The LC–FLD and LC–MS/MS method had LOD of 1.7–2.1 and 0.3–0.5 ng/mL, respectively, and showed excellent linear correlation over three orders of magnitude, obtained ideal recoveries (78.68–88.90%) and RSD (≤ 8%). The methods were successfully applied in multiple samples. For o- and m-tyrosine, the order of descending trend was: chicken > beef > hairtail > pork and chicken > hairtail > beef > pork, respectively. The radiation dose could be quantitatively evaluated by the nonlinear correlation (y = A₀x² + A₁x + A₂) with coefficients of determination r² > 0.998 in individual meat samples.     

QuEChERS-HPLC-MS/MS法检测谷类杂粮制品中4种真菌毒素

建立了一种快速、高效的QuEChERS-高效液相色谱-质谱联用法（QuEChERS-HPLC-MS/MS）测定谷类杂粮制品中脱氧雪腐镰刀菌烯醇（DON）、3-乙酰脱氧雪腐镰刀菌烯醇（3-ADON）、15-乙酰脱氧雪腐镰刀菌烯醇（15-ADON）和玉米赤霉烯酮（ZON）共4种真菌毒素。样品前处理采用乙腈-水溶剂提取,经Florisil+C18+无水硫酸镁净化后检测。以0.10%甲酸-乙腈作为流动相,在质谱检测器的多反应监测模式下进行分析。结果表明,4种真菌毒素在各自的线性范围内线性关系良好,相关系数R2均大于0.999,回收率在85.1%～102.0%,相对标准偏差（RSD）为2.11%～6.22%。该方法具有前处理简单、净化效果好、灵敏度高和检测速度快的优点,适用于谷类杂粮制品中DON、3-ADON、15-ADON 和ZON的分析和定量检测。     

花生油和玉米油中多组分真菌毒素高效液相色谱-串联质谱检测方法的建立

建立花生油和玉米油中黄曲霉毒素、玉米赤霉烯酮、单端孢霉烯族化合物等13种真菌毒素的高效液相色谱-串联质谱检测方法。样品经乙腈-水提取、Multi Sep 226多功能净化柱净化后,分别用电喷雾正离子模式和负离子模式检测。经优化,正离子模式流动相为含2 mmol/L甲酸铵的0.1%甲酸-甲醇溶液,负离子模式流动相为0.1%氨水-乙腈溶液。该方法对花生油和玉米油中13种真菌毒素的检出限为0.05~3.00μg/kg,定量限为0.10~10.00μg/kg,平均加标回收率为66.6%~114.9%。所建方法操作简单、灵敏度高、重复性好,可用于花生油和玉米油中多组分真菌毒素的协同测定。     

Incidence of trichothecenes and zearalenone in poultry feed mixtures from Slovakia

A total of 50 samples of poultry feed mixtures of Slovakian origin were analyzed for eight toxicologically significant Fusarium mycotoxins, namely zearalenone (ZON), A-trichothecenes: diacetoxyscirpenol (DAS), T-2 toxin (T-2) and HT-2 toxin (HT-2) and B-trichothecenes: deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON) and nivalenol (NIV). The A-trichothecenes and the B-trichothecenes were detected by means of high pressure liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and gas chromatography electron capture detection (GC-ECD), respectively. Reversed phase-high performance liquid chromatography with a fluorescence detector (RP-HPLC-FLD) was used for ZON detection. The most frequent mycotoxin detected was T-2, which was found in 45 samples (90%) in relatively low concentrations ranging from 1 to 130 microg kg(-1) (average 13 microg kg(-1)), followed by ZON that was found in 44 samples (88%) in concentrations ranging from 3 to 86 microg kg(-1) (average 21 microg kg(-1)). HT-2 and DON were detected in 38 (76%) and 28 (56%) samples, respectively, in concentrations of 2 to 173 (average 18 microg kg(-1)) for HT-2 and 64 to 1230 microg kg(-1) sample (average 303 microg kg(-1)) for DON. The acetyl-derivatives of DON were in just four samples, while NIV was not detected in any of the samples investigated. In as many as 22 samples (44%), a combination of four simultaneously co-occurring mycotoxins, i.e. T-2, HT-2, ZON and DON, was revealed. Despite the limited number of samples investigated during this study poultry feed mixtures may represent a risk from a toxicological point of view and should be regarded as a potential source of the Fusarium mycotoxins in Central Europe. This is the first reported study dealing with zearalenone and trichothecene contamination of poultry mixed feeds from Slovakia.     

Occurrence of Fusarium mycotoxins in maize imported into the UK, 2004–2007

This study examined a total of 82 consignments of French and Argentinean raw maize as received at maize mills in the UK between 2004 and 2007. Samples were analysed for deoxynivalenol (DON), nivalenol (NIV), other trichothecenes, zearalenone (ZON), and fumonisins B₁, B₂, and B₃ (FB₁, FB₂, and FB₃) using fully validated analytical methods with limits of quantification of 10 µg kg^?1 for DON, NIV, and each fumonisin mycotoxin and 3 µg kg^?1 for ZON. All samples except two containing fumonisins met the European Commission statutory maximum permissible levels for DON, ZON, and FB₁ + FB₂ as operating in 2007. The maximum concentrations found for DON, NIV, ZON, and FB₁ + FB₂ were 444, 496, 165 and 5002 µg kg^?1, respectively. Fumonisins were detected in almost every sample with 65% of Argentinean maize containing more than 1000 µg kg^?1 of FB₁ + FB₂. In contrast, ZON was not detectable in almost 50% of consignments. During this period there was a distinct difference in mycotoxin concentrations between harvests and geographic origin. Flint maize from Argentina usually contained lower concentrations of DON and related trichothecenes and higher levels of fumonisins than maize from France, although concentrations of fumonisins up to 2000 µg kg^?1 or greater occurred in samples from both regions. The incidence and concentrations of fumonisins were similar to those in a similar previous survey, while zearalenone concentrations were lower. The distribution of mycotoxins in multi-hold ships was also investigated showing that fumonisins were much more evenly distributed than DON, thus indicating their general level in the ship as a whole. The effect of cleaning regimes was found to be very variable, especially for DON, ranging from no removal of mycotoxins to greater than 50% in some instances, but was not related to concentration. Evidence here suggests that while cleaning is essential for removing foreign bodies before milling, it cannot be used as a reliable tool for reducing mycotoxins.     

Quantification of mycotoxins in vegetable oil by UPLC-MS/MS after magnetic solid-phase extraction

ABSTRACT

The detection of mycotoxin contamination in foodstuffs is highly significant for public health. Herein we report an analytical method based on magnetic solid-phase extraction (MSPE) and UPLC-MS/MS for the simultaneous determination of mycotoxins, including fumonisins B₁ (FB₁), zearalenone (ZON) and ochratoxin A (OTA), in vegetable oil. Magnetic nanoparticles coated with double layers of silicon dioxide were synthesised and found to be an effective MSPE adsorbent for mycotoxins. The proposed MSPE procedure serves not only for sample clean-up but also for mycotoxin enrichment that enhances greatly the assay’s sensitivity. Under the selected MSPE conditions, linear matrix-matched calibration curves were obtained for mycotoxins in a concentration range from 0.178 to 625 μg kg^–1. The limits of detection were 0.210 μg kg^–1 for FB₁, 0.0800 μg kg^–1 for OTA and 1.03 μg kg^–1 for ZON. The proposed MSPE UPLC-MS/MS method was applied for the determination of mycotoxins in vegetable oil samples, including maize oil, rapeseed oil and soybean oil. ZON was detected in a maize oil at 101 μg kg^–1, which is below the European Union limit of 200 μg kg^–1 in foodstuffs.     

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.     

Distribution of Fusarium mycotoxins in UK wheat mill fractions

The EU has set maximum limits for the Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZON). The maximum permitted level decreases from unprocessed wheat, through intermediary products, e.g. flour, to finished products such as bakery goods and breakfast cereals. It is, therefore, important to understand the effects of processing on the mycotoxin distribution in mill fractions. Between 2004 and 2007, samples were taken at commercial flour mills at various points in the milling process and analysed for trichothecenes and ZON. Samples with a range of mycotoxin concentrations harvested in 2004 and 2005 were processed in a pilot mill and the mycotoxins in the different mill fractions quantified. In the commercial samples, DON was the predominant mycotoxin with highest levels detected in the bran fraction. Analysis of the pilot mill fractions identified a significant difference between the two years and between mycotoxins. The proportion of DON and nivalenol in the mill fractions varied between years. DON and nivalenol were higher in flour fractions and lower in bran and offal in samples from 2004 compared to samples from 2005. This may be a consequence of high rainfall pre-harvest in 2004 resulting in movement of these mycotoxins within grains before harvest. There was no significant difference in the distribution of ZON within mill fractions between the two years. For DON, higher concentrations in the grain resulted in a greater proportion of DON within the flour fractions. Understanding the factors that impact on the fractionation of mycotoxins during milling will help cereal processors to manufacture products within legislative limits.