Stability of the mycotoxin deoxynivalenol (DON) during the production of flour-based foods and wheat flake cereal

Deoxynivalenol (DON) is a mycotoxin found in cereal grains and cereal-based foods. DON concentrations in finished products are reduced under some processing conditions, but not others. DON concentrations in flour, wheat and selected foods made from them under commercially relevant conditions were compared by GC with electron capture detection. Average concentrations (n = 9/item) in cookies, crackers and pretzels ranged from 61% (cookies) to 111% (pretzels) compared with flour (100% = 0.46 μg g?1). Lesser amounts were found in donuts and bread: their respective DON concentrations were 44% and 30% that of flour. Mass balance estimates for DON (μg g?1 flour equivalents) ranged from 50% (bread = 0.23 μg g?1 flour equivalents) to 120% (donuts), indicating that dilution by recipe ingredients contributed to DON reductions in bread and accounted for all of the apparent reduction in donuts. Mass balance estimates averaged 76% (crackers) to 107% (pretzels) for the other flour products. DON concentrations were higher in cereal flakes (0.55 μg g?1 in the finished product and 0.58 μmg g?1 on a mass balance basis) than in wheat (0.40 μg g?1), suggesting that DON concentrations might increase during processing of wheat cereals under some conditions. In summary, DON concentrations of finished food products were reduced ≥ 50% only in bread and donuts. Reduction in bread resulted from a combination of DON ‘loss’ and dilution by recipe ingredients whereas the reduction in donuts was due entirely to dilution. These results are further evidence of DON stability during the preparation of popular flour or wheat-based products.     

Stability of the mycotoxin deoxynivalenol (DON) during the production of flour-based foods and wheat flake cereal

Deoxynivalenol (DON) is a mycotoxin found in cereal grains and cereal-based foods. DON concentrations in finished products are reduced under some processing conditions, but not others. DON concentrations in flour, wheat and selected foods made from them under commercially relevant conditions were compared by GC with electron capture detection. Average concentrations (n?=?9/item) in cookies, crackers and pretzels ranged from 61% (cookies) to 111% (pretzels) compared with flour (100%?=?0.46?µg?g^?1). Lesser amounts were found in donuts and bread: their respective DON concentrations were 44% and 30% that of flour. Mass balance estimates for DON (µg?g^?1 flour equivalents) ranged from 50% (bread?=?0.23?µg?g^?1 flour equivalents) to 120% (donuts), indicating that dilution by recipe ingredients contributed to DON reductions in bread and accounted for all of the apparent reduction in donuts. Mass balance estimates averaged 76% (crackers) to 107% (pretzels) for the other flour products. DON concentrations were higher in cereal flakes (0.55?µg?g^?1 in the finished product and 0.58?µg?g^?1 on a mass balance basis) than in wheat (0.40?µg?g^?1), suggesting that DON concentrations might increase during processing of wheat cereals under some conditions. In summary, DON concentrations of finished food products were reduced?≥50% only in bread and donuts. Reduction in bread resulted from a combination of DON ‘loss’ and dilution by recipe ingredients whereas the reduction in donuts was due entirely to dilution. These results are further evidence of DON stability during the preparation of popular flour or wheat-based products.     

Exposure of consumers to deoxynivalenol from consumption of white bread in Hungary

In view of the frequent occurrence of mycotoxins in cereals, a study was initiated to assess the exposure of the Hungarian adult population. Consumption data for 1360 individuals, based on a 3-day questionnaire, indicated that white bread accounted for the major intake of cereal-based products. Various cereal products were analysed for 16 mycotoxins by a LC/MS/MS multi-toxin method with LOD of 16 μg kg?1 and LOQ of 50 μg kg?1. Deoxynivalenol (DON) was most frequently detected, but no acetyl-deoxynivalenol was present in detectable concentrations. Consumer exposure was calculated with standard Monte Carlo probabilistic modelling and point estimates, taking into account bread consumption and DON contamination in independently taken wheat flour and wheat grain samples. Over 55% of cases the DON intake were below 15% of the provisional maximum tolerable daily intake (PMTDI) of 1 μg/(kg bw)/day. However, in 5-15% of cases, the intake from bread consumption alone exceeded the PMTDI. Wheat grain data led to the higher percentage. Intakes estimated from both data sets were at or below the acute reference dose (ARfD) of 8 μg/(kg bw)/day in 99.94-99.97% of cases.     

Exposure of consumers to deoxynivalenol from consumption of white bread in Hungary

In view of the frequent occurrence of mycotoxins in cereals, a study was initiated to assess the exposure of the Hungarian adult population. Consumption data for 1360 individuals, based on a 3-day questionnaire, indicated that white bread accounted for the major intake of cereal-based products. Various cereal products were analysed for 16 mycotoxins by a LC/MS/MS multi-toxin method with LOD of 16?µg?kg^?1 and LOQ of 50?µg?kg^?1. Deoxynivalenol (DON) was most frequently detected, but no acetyl-deoxynivalenol was present in detectable concentrations. Consumer exposure was calculated with standard Monte Carlo probabilistic modelling and point estimates, taking into account bread consumption and DON contamination in independently taken wheat flour and wheat grain samples. Over 55% of cases the DON intake were below 15% of the provisional maximum tolerable daily intake (PMTDI) of 1?µg/(kg?bw)/day. However, in 5–15% of cases, the intake from bread consumption alone exceeded the PMTDI. Wheat grain data led to the higher percentage. Intakes estimated from both data sets were at or below the acute reference dose (ARfD) of 8?µg/(kg?bw)/day in 99.94–99.97% of cases.     

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.     

Optimization of a fluorescence polarization immunoassay for rapid quantification of deoxynivalenol in durum wheat-based products

A fluorescence polarization immunoassay previously described for deoxynivalenol (DON) screening in wheat was optimized for the rapid quantification of DON in durum wheat kernels, semolina, and pasta. A background signal was observed in both spiked and naturally contaminated samples, strictly depending on the testing matrix. After subtracting the background DON level for durum wheat (0.27 microg of DON per g), semolina (0.08 microg of DON per g), and pasta (0.04 microg of DON per g), an accurate quantification of DON was possible at levels greater than 0.10 microg/g for all matrices. Average recoveries from spiked samples (0.25 to 1.75 microg/g) were 98, 102, and 101% for wheat, semolina, and pasta, respectively. Comparative analyses of 35 naturally contaminated durum wheat samples, 22 semolina samples, and 26 pasta samples performed by both the fluorescence polarization method and high-pressure liquid chromatography/immunoaffinity cleanup showed a good correlation (r > 0.995). The fluorescence polarization method showed better accuracy and precision with respect to the high-pressure liquid chromatography method and is suitable for the rapid and quantitative determination of DON in durum wheat-based products at levels foreseen by existing or coming international regulations.     

添加发芽小麦对小麦粉及制品品质影响

在小麦中添加不同比例的发芽小麦,研究对小麦、小麦粉品质特性及食用品质的影响。选择发芽小麦按照不同比例(1%、5%、10%、15%、20%、25%、30%)与正常小麦进行混合,研究发芽小麦不同添加比例对小麦及小麦粉品质特性产生的影响,并对不同添加比例发芽小麦粉制作的馒头和面条食用品质进行评价。结果表明:随着发芽小麦比例含量的增加,混合小麦及小麦粉品质特性指标中除降落数值逐渐减少,其他特性指标与正常小麦相比较无明显变化。对馒头和面条进行蒸煮实验评价,可以看出当发芽小麦含量不超过15%时,对其食用品质无明显影响,但当发芽小麦含量超过20%时,馒头出现粘牙,当发芽小麦含量超过15%时,面条韧性下降,食用品质受到影响,评分值均在80分以下。     

Aflatoxin B1 and sterigmatocystin in wheat and wheat products from supermarkets in China

Wheat is an important cereal but it is often contaminated with mycotoxins. The natural occurrence of aflatoxin B₁ (AFB₁) and sterigmatocystin (STC) was determined in 178 food samples (32 wheat samples and 146 wheat products) purchased from Chinese supermarkets. The methodology was validated, the wheat and wheat products samples were treated with a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). From these samples 18.8% of wheat and 8.2% of cracker samples were contaminated with AFB₁. Mean levels were 0.06 µg/kg and 0.05µg/kg, respectively. There was no AFB₁ contamination in white bread or whole meal bread. Meanwhile 53.1% of wheat, 59.2% of crackers, 20.8% of white bread and 16% of whole meal bread samples were contaminated with STC. The mean levels were 0.07, 0.79, 0.12 and 0.12 µg/kg respectively. Although the levels were low, this demonstrates the need for more comprehensive surveys for these two mycotoxins in wheat and wheat products from China.     

Natural co-occurrence of deoxynivalenol and fumonisins B1 and B2 in Italian marketed foodstuffs

A survey was performed to obtain the frequency and levels of contamination by deoxynivalenol (DON) and fumonisins B₁ and B₂ (FB1, FB2) mycotoxins in Italian marketed foods. Of 202 samples investigated, including raw materials and processed cereal foods (bread, pasta, breakfast cereals, biscuits, baby and infant foods), 84% were contaminated with DON at levels from 0.007 to 0.930 μg g^-1 (median 0.065 μg g^-1); 26% contained FB1 ranging from 0.010 to 2.870 μg g^-1 (0.070 μg g^-1); 35% contained FB2 at 0.010-0.790 μg g^-1 (0.080 μg g^-1). The highest levels of DON and FB1 were detected in raw cereals and wholemeal flours. The highest levels of FB2 were detected in durum wheat pasta. A widespread DON contamination was found in baby and infant foods at levels varying from 0.007 to 0.166 μg g^-1.     

Acrylamide-asparagine relationship in baked/toasted wheat and rye breads

Acrylamide in baked and toasted wheat and rye bread was studied in relation to levels of asparagine in flour, dough, bread and toasts. Asparagine was consumed during bread preparation resulting in reduced acrylamide content in the products. In wheat bread, 12% of the asparagine initially present in the flour (0.14 g kg(-1)) remained after yeast fermentation and baking; for rye bread, 82% of asparagine remained after sourdough fermentation and baking. Asparagine present in untoasted wheat bread had totally reacted after hard toasting. Toasted wheat and rye bread slices contained 11-161 and 27-205 microg kg(-1) acrylamide, respectively, compared to untoasted wheat and rye bread with <5 and 7-23 microg kg(-1) acrylamide, respectively. The dietary intake of acrylamide from bread (untoasted) of 2 microg day(-1) is relatively low; however, acrylamide exposure from bread increases several fold for people eating toasted bread.     

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.     

Occurrence of deoxynivalenol (vomitoxin) in processed cereals and pulses in Turkey

The aim was to investigate the occurrence of deoxynivalenol (DON) in cereal and pulse products in Turkey. DON was detected using high-performance liquid chromatography (HPLC) with ultraviolet detection at 220 nm and positive results greater or equal to 0.60 ppm were confirmed by thin layer chromatography (TLC). An acetonitrile-water (21:4 v/v) extract of the sample was cleaned up on a column packed with alumina-Celite-charcoal (0.35 + 0.25 + 0.40 g). The detection limits for DON were 3 ng/injection (0.10 ppm) and 50 ng/spot (0.60 ppm) for HPLC and TLC, respectively. Eighty-three commercially available cereal and pulse product samples collected from markets and street bazaars were analysed. The recovery rates for boiled, pounded wheat and rice spiked with added DON (1 ppm) were 80.9% (SD 8.37, n =5) and 72.3% (3.85, n =5), respectively. DON was detected in six (8.82%) of 68 cereal and in none of 15 pulse products. The maximum detected amount was 2.67 ppm in a corn flour sample.     

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.     

Determination of trichothecenes in cereals and cereal-based products by liquid chromatography-tandem mass spectrometry

A sensitive, accurate and precise method for the simultaneous determination of nivalenol (NIV), deoxynivalenol (DON), T-2 toxin (T-2) and HT-2 toxin (HT-2) in different food matrices, including wheat, maize, barley, cereal-based infant foods, snacks, biscuits and wafers, has been developed. The method, using liquid chromatography coupled with atmospheric pressure chemical ionization triple quadrupole mass spectrometry (LC-APCI-MS/MS), allowed unambiguous identification of the selected trichothecenes at low µg per kg levels in such complex food matrices. A clean-up procedure, based on reversed phase SPE Oasis® HLB columns, was used, allowing good recoveries for all studied trichothecenes. In particular, NIV recoveries significantly improved compared to those obtained by using Mycosep® #227 columns for clean-up of the extracts. Limits of detection in the various investigated matrices ranged 2.5-4.0 µg kg^-1 for NIV, 2.8-5.3 µg kg^-1 for DON, 0.4-1.7 µg kg^-1 for HT-2 and 0.4-1.0 µg kg^-1 for T-2. Mean recovery values, obtained from cereals and cereal products spiked with NIV, DON, HT-2 and T-2 toxins at levels from 10 to 1000 µg kg^-1, ranged from 72 to 110% with mean relative standard deviation lower than 10%. A systematic investigation of matrix effects in different cereals and cereal products was also carried out by statistically comparing the slopes of standard calibration curve with matrix-matched calibration curve for each of the four toxins and the eight matrices tested. For seven of the eight matrices tested, statistically significant matrix effects were observed, indicating that, for accurate quantitative analysis, matrix-matched calibration was necessary. The method was applied to the analysis of 57 samples of ground wheat originated from South Italy and nine cereal food samples collected from retail markets.     

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.     

Fluorescence polarization as a tool for the determination of deoxynivalenol in wheat.

The mould Fusarium graminearum is found worldwide as a pathogen of cereal grains, in particular of wheat and maize, and it produces a mycotoxin known as deoxynivalenol (DON or vomitoxin). Each year, the presence of this compound and related trichothecenes causes substantial losses to agricultural productivity. Rapid methods for the measurement of the toxin in grains are required to monitor and divert effectively contaminated grain from the food supply. A fluorescence polarization (FP) immunoassay using a previously described monoclonal antibody for DON was developed. The assay was based on the competition of unlabeled DON from a sample with a fluorescently tagged DON, DON-fluorescein (DON-FL), for a DON-specific monoclonal antibody in solution. The FP of the tagged DON was increased upon binding with the antibody. In the presence of free toxin, less of the DON-FL was bound and the polarization signal was decreased. The assays were very simple to perform, requiring only mixing of an aqueous extract of wheat with the DON-FL and antibody. The sensitivity of the assay was strongly dependent upon the time between mixing of the sample with the tracer and measurement of the fluorescence polarization, with midpoints for the competition curves ranging from 0.03 microg ml(-1) with a 15-s incubation to >1 microg ml(-1) with a 12-min incubation. Samples of wheat naturally contaminated with DON were evaluated by FP and by an HPLC-UV method, with a good correlation (r2 = 0.97). Although the FP method tended to overestimate DON slightly in the wheat samples, by approxiamtely 20%, the assay was easy to use and very useful for the screening of wheat.     

Determination of total mercury in foods of plant origin in Poland by cold vapour atomic absorption spectrometry.

Total mercury concentrations were determined in 573 samples of agricultural crops and foods of plant origin which included cereals, fruit and vegetables and their products commercially available on the Polish market. The method of cold vapour atomic absorption spectrometry (CVAAS) after a wet-acid digestion in a closed-vessels and microwave oven was used and the reliability of the procedure demonstrated. Mercury concentrations in the agricultural crops and plant foods were generally below the maximum permissible limits in Poland and rarely exceeded 5 microg x kg(-1). Values ranged from <0.1 to 14 microg x kg(-1), mean 2.4 +/- 2.3 microg x kg(-1) in wheat and rye grains; from <0.1 to 2.4 microg x kg(-1), mean 0.5 +/- 0.4 microg x kg(-1) in nine varieties of vegetables; from <0.1 to 5.1 microg x kg(-1), mean 1.1 +/- 0.9 microg x kg(-1) in seven varieties of fruit; from <0.1 to 5.6 microg x kg(-1) in cereal products and jams; and from <0.1 to 3.0 microg x l(-1) in fruit and vegetable juices, nectars and beverages. The contribution of the mercury in the analysed agricultural crops and foods of plant origin to the weekly dietary intake of total mercury was 8 microg/person, which represents only 3% of the provisional tolerable weekly intake (PTWI) for this metal.     

Effect of fermentation on naturally occurring deoxynivalenol (DON) in Argentinean bread processing technology.

The stability of naturally occurring DON was evaluated during the fermentation stage of the bread-making process on a pilot scale. Two different products, French bread and Vienna bread, were prepared with naturally contaminated wheat flour (150 mg kg(-1)) under controlled experimental conditions. Dough was fermented at 30, 40 and 50 degrees C according to standard procedures employed in Argentinean low-technology bakeries. When the dough was fermented at 50 degrees C, the maximum reduction was 56% for the Vienna bread, with French bread being reduced by 41%. DON reduction during bread-making occurs not only in the baker due to thermal decomposition, but also during the fermentation step. The Argentinean traditional bread-making process might reduce DON levels during the fermentation stages if the dough is leavened at temperatures > 30 degrees C.     

Contaminants in organically and conventionally produced winter wheat (Triticum aestivum) in Belgium

A database has been compiled with the levels of important contaminants (mycotoxins, heavy metals and pesticides) measured from 2002 to 2005 in winter wheat (Triticum aestivum) grown in Belgium according to the organic and conventional farming systems. Assuming no further change in contaminant levels during cereal processing and during the preparation of foodstuffs, conservative intakes are estimated for the consumers of cereal-based products such as flour, bread, breakfast cereals, dough and pastry. The results show that for the consumer of organic foodstuffs, estimated daily intakes are 0.56 µg deoxynivalenol (DON), 0.03 µg zearalenone (ZEA), 0.19 µg Cd, 0.28 µg Pb and 0.0006 µg Hg kg^-1 body weight, taking into account the average contaminant levels in unprocessed grains and the average cereal products consumptions in Belgium. For the consumers of conventional foodstuffs, the corresponding estimated daily intakes are 0.99 µg DON, 0.06 µg ZEA, 0.17 µg Cd, 0.12 µg Pb and 0.0007 µg Hg kg^-1 body weight. In addition, it appears that for the consumers of conventional products, intakes of some post-harvest insecticides have to be taken into account (0.11 µg chlorpyriphos-methyl, 0.2 µg dichlorvos and 0.24 µg pirimiphos-methyl kg^-1 bw). When expressed as a percentage of the tolerable/acceptable daily intake (TDI/ADI), it seems that the corresponding estimated (conservative) intakes are the highest for DON (56% for organic and 99% for conventional cereal products), ZEA (16% for organic and 32% for conventional cereal products), and Cd (19% for organic and 17% for conventional cereal products), all other estimated intakes of contaminants (including pesticides) being lower than 10% of the TDI/ADI.     

Immunoassay based on monoclonal antibodies versus LC-MS: deoxynivalenol in wheat and flour in Southern Brazil

An indirect competitive enzyme-linked immunosorbent assay (ELISA) method using a monoclonal antibody for deoxynivalenol (DON) detection in wheat and flour was standardised and validated (detection limit?=?177.1?μg?kg(-1)) and its performance was compared with LC-MS, quantification limit?=140?μg?kg(-1)). DON recovery ranged from 88.7% to 122.6% for wheat grain and from 70.6% to 139.3% for flour. Among the 38 wheat samples evaluated, DON was detected in 29 samples (76.3%) by ic-ELISA (281.6-12?291.4?μg?kg(-1)) and in 22 samples (57.9%) by LC-MS (155.3-9906.9?μg?kg(-1)). The 0.93 correlation coefficient between ic-ELISA and LC-MS data in 19 positive DON wheat samples demonstrated the reliability and efficiency of ic-ELISA. Results indicated that standardised ic-ELISA was suitable for DON screening in wheat samples and the need for continuous monitoring of mycotoxin levels in foodstuffs.