Search

Fumonisin B1 (FB1) is a representative form of fumonisin and is widely present in food and feed. Hydrolyzed fumonisin B1 (HFB1) emerges as a breakdown product of FB1, which is accompanied by FB1 alterations. While previous studies have primarily focused on the liver or kidney toxicity of FB1, with limited studies existing on its neurotoxicity and even fewer on the toxicity of HFB1, this study focuses on the neurotoxicity of FB1 and HFB1 exposure in mice investigated by the open field test, Morris water maze test, histopathological analysis, and nontargeted metabolomics. Further, the levels of oxidative stress-related indices, neurotransmitters, and sphingolipids in the brain were measured to analyze their correlation with behavioral outcomes. The results showed that both FB1 (5 mg/kg) and HFB1 (2.8 mg/kg) reduced autonomous exploratory behavior in mice, impaired spatial learning and memory, and caused mild abnormalities in the brain structure. Quantitative analysis further indicated that exposure to FB1 and HFB1 disrupted neurotransmitter homeostasis, exacerbated oxidative stress, and significantly increased the sphinganine/sphingosine (Sa/So) ratio. Moreover, HFB1 exhibited neurotoxic effects similar to those of FB1, emphasizing the need to pay attention to the neurotoxicity effect of HFB1. These findings underscore the importance of understanding the risks and potential neurological damage associated with FB1 and HFB1 exposure, highlighting the necessity for further research in this crucial field.

Rice spikelet rot disease (RSRD) caused by Fusarium proliferatum seriously reduces rice yield and produces mycotoxins that threaten human health. The root symbiotic endophytic fungus Phomopsis liquidambaris reduces RSRD incidence and fumonisins accumulation in grain by 21.5 and 9.3%, respectively, while the mechanism of disease resistance remains largely elusive. Here, we found that B3 significantly reduced the abundance of pathogen from 79.91 to 2.84% and considerably enriched resistant microbes Pseudomonas and Proteobacteria in the spikelet microbial community. Further study revealed that B3 altered the metabolites of spikelets, especially hordenine and l-aspartic acid, which played a key role in reshaping the microbiome and supporting the growth of the functional core microbe Pseudomonas , and inhibited the pathogen growth and mycotoxin production. This study provided a feasibility of regulating the function of aboveground microbial communities by manipulating plant subsurface tissues to control disease and mycotoxin pollutants in agricultural production.

The objective of the study was to investigate the efficacy of bentonite and fumonisin esterase, separately or combined, in mitigating the effects of aflatoxins (AF) and fumonisins (FUM) in Boran and Friesian-Boran crossbreed cattle. These effects were studied by measuring mycotoxins, their metabolites, and biomarkers that relate to animal health, productivity, and food safety. The study was divided into three experiments each lasting for 2 weeks. Cows in experiment 1 received in random order aflatoxin B1 (AFB1) [788 μg/cow/day (69.7 μg/kg dry matter intake (DMI)) for Borans and 2,310 μg/cow/day (154 μg/kg DMI) for crossbreeds], bentonite (60 g/cow/day), or both AFB1 and bentonite. Boran cows in experiment 2 received in random order FUM (12.4 mg/cow/day (1.1 mg/kg DMI)), fumonisin esterase (120 U/cow/day), or both FUM and fumonisin esterase. Boran cows in experiment 3 received in random order AFB1 (952 μg/cow/day (84.2 μg/kg DMI)) + FUM (30.4 mg/cow/day (2.7 mg/kg DMI)), bentonite (60 g/cow/day) + fumonisin esterase (120 U/cow/day), or both AFB1 + FUM and bentonite + fumonisin esterase. Feeding AFB1 and/or FUM contaminated feed with or without the addition of the detoxifiers for 14 days did not affect DMI, milk composition, hematology, and blood biochemical parameters. The addition of bentonite in a diet contaminated with AFB1 led to a decrease in milk aflatoxin M1 (AFM1) concentration of 30% and 43%, with the carry-over subsequently decreasing from 0.35% to 0.20% and 0.08% to 0.06% for crosses and Borans, respectively. No significant change was observed in the sphinganine/sphingosine (Sa/So) ratio following feeding with FUM alone or in combination with fumonisin esterase; however, the ability of fumonisin esterase to hydrolyze FUM into less toxic fully hydrolyzed FUM and partially hydrolyzed FUM was evident in the rumen fluid and feces. These results indicate bentonite was effective in decreasing AFM1 concentration in milk, and AFB1 and AFM1 in plasma, while fumonisin esterase can convert FUM into less toxic metabolites and can be a suitable addition to feed cocontaminated with AFB1 and FUM.

Various mycotoxins widely co-exist in agro-products, and their combined effects cause toxicity and potential carcinogenicity to humans and animals. In this work, we developed an economical and sensitive quantum dots (QDs)/QD microbead (QDs/QB)-based multiplex immunochromatographic assay (mICA) for the rapid detection of fumonisin B 1 (FB 1 ), zearalenone (ZEN), and ochratoxin A (OTA) without the building-up process of mycotoxin conjugates. QDs and QBs were selected as fluorescent reporters and conjugated with antimycotoxin monoclonal antibodies for improving sensitivity. Furthermore, phage-displayed FB 1 , ZEN, and OTA mimotope peptide-based soluble and monovalent fusions to maltose-binding protein (MBP) were applied onto the test line of the mICA as the mimetic coating antigen. Under the optimized conditions, the visual detection limits (vLODs) of peptide-MBP-based mICA could be obtained as 0.25 ng/mL for FB 1 , 3.0 ng/mL for ZEN, and 0.5 ng/mL for OTA within 10 min. The results for spiked real sample detection indicate good accuracy, reproducibility, and practicability. In addition, the proposed mICA was comparable with ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) in terms of reliability in detecting FB 1 , ZEN, and OTA using natural samples. From the point of promoting commercial production, these time-saving and low-cost peptide-MBP antigens applied in ICA might provide promising potential for promoting productivity and decreasing the cost of production.

The quantitative multiplex immunochromatographic assay (mICA) has received an increasing amount of attention in multitarget detection. However, the quantitative results in the reported mICAs were obtained by recording the signals on the test lines that with which various analyte-independent factors readily interfere, resulting in inaccurate quantitation. The ratiometric strategy using the T/C value (ratios of signals on the test line to those of the control line) for signal correction can effectively circumvent these issues to enable more accurate detection. Herein, we present for the first time a novel ratiometric mICA strip with multiple T lines for the simultaneous quantitative detection of aflatoxin B 1 (AFB 1 ), fumonisin B 1 (FB 1 ), and ochratoxin A (OTA) using highly luminescent quantum dot nanobeads (QBs) as enhanced signal reporters. To achieve reliable ratiometric signal output, a biotin-streptavidin system was introduced to replace the conventional anti-mouse IgG antibody for reliable reference signals on the control line that are completely independent of the signal probe and analyte. By using stable T/C values as quantitative signals, our proposed QB-mICA method can successfully detect three mycotoxins with concentrations as low as 1.65 pg/mL for AFB 1 , 1.58 ng/mL for FB 1 , and 0.059 ng/mL for OTA. The detection performance of the developed QB-mICA strip, including precision, specificity, and reliability, was further evaluated using artificially contaminated cereal samples. The results demonstrate the improved accuracy and reliability of quantitative determination by comparison with the anti-mouse IgG antibody. Thus, this work provides a promising strategy for developing a ratiometric mICA method for accurately quantifying multiple analytes using the biotin-SA system, opening up a new direction in quantitative mICAs.

Mycotoxins are secondary metabolites produced by various molds that contaminate many staple foods and cause a broad range of detrimental health effects in animals and humans through chronic exposure or acute toxicity. As such, the worldwide contamination of food and feed with mycotoxins is a significant problem, especially in sub-Saharan Africa. In this study, mycotoxin occurrence in staple foods consumed in Somalia was determined. A total of 140 samples (42 maize, 40 sorghum, and 58 wheat) were collected from a number of markets in Mogadishu, Somalia, and analyzed by a UPLC-MS/MS multimycotoxin method that could detect 77 toxins. All of the maize samples tested contained eight or more mycotoxins, with aflatoxin B 1 (AFB 1 ) and fumonisin B 1 (FB 1 ) levels reaching up to 908 and 17 322 μg/kg, respectively, greatly exceeding the European Union limits and guidance values. The average probable daily intake of fumonisins (FB 1 and FB 2 ) was 16.70 μg per kilogram of body weight (kg bw) per day, representing 835% of the recommended provisional maximum tolerable daily intake value of 2 μg/(kg bw)/day. A risk characterization revealed a mean national margin of exposure of 0.62 for AFB 1 with an associated risk of developing primary liver cancer estimated at 75 cancers per year per 100 000 people for white-maize consumption alone. The results clearly indicate that aflatoxin and fumonisin exposure is a major public-health concern and that risk-management actions require prioritization in Somalia.

Fungicides and, for the first time, microalgal phenolic extracts (MPE) from Spirulina sp. and Nannochloropsis sp. were applied on maize culture media under field conditions to evaluate their ability to minimize Fusarium species development and fumonisin production. An in vitro assay against F. verticillioides was carried out using maize grains as the culture medium. An open-field experiment was carried out in Northwest Italy under natural infection conditions. The compared treatments were factorial combinations of two insecticide treatments (an untreated control and pyrethroid, used against European Corn Borer), four antifungal treatments (an untreated control, MPE from Spirulina sp., MPE from Nannochloropsis sp., and a synthetic fungicide), and two timings of the application of the antifungal compounds (at maize flowering and at the milk stage). The MPE compounds were capable of inhibiting fumonisin production in vitro more efficiently than tebuconazole. Insecticide application reduced the infection by Fusarium species and subsequent fumonisin contamination. However, fumonisins in maize fields were not significantly controlled by either fungicide or MPE application.

This study estimated exposure to multiple mycotoxins in 249 infants aged between 6 and 12 months in three agro-ecological zones of Tanzania. Maize-based complementary food intakes were estimated using two 24 h dietary recalls. Using @Risk software, probabilistic exposure assessment was conducted by modeling maize intake data (kg/kg body weight/day) with previously determined multiple mycotoxin (except for ochratoxin A (OTA) and zearalenone (ZEA), present in only a few samples) contamination data (μg/kg) in maize. Maize intakes ranged from 0.13 to 185 g/child/day (average = 59 ± 36 g/child/day). The estimated mean exposures were higher for aflatoxins (6-fold), fumonisins (3-fold), and deoxynivalenol (2-fold) than health-based guidance values of 0.017 ng/kg body weight/day, 2 μg/kg body weight/day, and 1 μg/kg body weight/day, respectively. The population at risk of exposures above the limits of health concern ranged from 12% for HT-2 toxin through 35% for deoxynivalenol to 100% for aflatoxins. The exposure varied among the agro-ecological zones. Strategies targeting multiple mycotoxins in maize are urgently needed to minimize exposures in Tanzania.

An epidemic fungal disease caused by Fusarium proliferatum, responsible for fumonisin production (FB1, FB2, and FB3), has been reported in the main garlic-producing countries in recent years. Fumonisins are a group of structurally related toxic metabolites produced by this pathogen. The aim of this work was to establish an enzyme-linked immunosorbent assay (ELISA) procedure, mostly applied to cereals, that is suitable for fumonisin detection in garlic and compare these results to those obtained by high-performance liquid chromatography (HPLC) and screening of fresh and dehydrated garlic for toxicological risk. The results show good correlation between the two analytical methods. In fresh symptomatic garlic, fumonisin levels were higher in the basal plates than those in the portions with necrotic spots. Among the 56 commercially dehydrated garlic samples screened, three were positive by ELISA test and only one was above the limit of quantitation. The same samples analyzed by HPLC showed the presence of FB1 in trace amounts that was below the limit of quantitation; FB2 and FB3 were absent. The results are reassuring, because no substantial contamination by fumonisins was found in commercial garlic.

Ultrahigh-performance liquid chromatography using positive electrospray ionization and quadrupole orbital ion trap high-resolution mass spectrometry was evaluated for analyzing mycotoxins in finished cereal and nut products. Optimizing the orbital ion trap mass analyzer in full-scan mode using mycotoxin-fortified matrix extracts gave mass accuracies, δM, of < ± 2.0 ppm at 70,000 full width at half maximum (FWHM) mass resolution (RFWHM). The limits of quantitation were matrix- and mycotoxin-dependent, ranging from 0.02 to 11.6 μg/kg. Mean recoveries and standard deviations for mycotoxins from acetonitrile/water extraction at their relevant fortification levels were 91 ± 10, 94 ± 10, 98 ± 12, 91 ± 13, 99 ± 15, and 93 ± 17% for corn, rice, wheat, almond, peanut, and pistachio, respectively. Nineteen mycotoxins with concentrations ranging from 0.3 (aflatoxin B1 in peanut and almond) to 1175 μg/kg (fumonisin B1 in corn flour) were found in 35 of the 70 commercial grain and nut samples surveyed. Mycotoxins could be identified at δM < ± 5 ppm by identifying the precursor and product ions in full-scan MS and data-dependent MS/MS modes. This method demonstrates a new analytical approach for monitoring mycotoxins in finished grain and nut products.

This paper reports the development of a screening fluorescence polarization immunoassay (FPIA) for the simultaneous detection of fumonisins B1 (FB1) and B2 (FB2) in maize. Three FB1 tracers including FB1-fluorescein isothiocyanate isomer I (FB1-FITC), FB1-5-([4,6-dichlorotriazine-2-yl]amino)-fluorescein (FB1-5-DTAF), and FB1-Texas Red-X succinimidyl ester (FB1-TRX) were synthesized and studied to select appropriate tracer-antibody pairs using seven previously produced monoclonal antibodies (mAbs). An FPIA employing the pair of FB1-FITC and mAb 4B9 showing 98.9% cross-reactivity (CR) toward FB2 was used to simultaneously detect FB1 and FB2. Maize flour samples were extracted with methanol/water (2:3, v/v). After optimization, the FPIA revealed a limit of detection (LOD) of 157.4 μg/kg for FB1 and an LOD of 290.6 μg/kg for FB2, respectively. Recoveries were measured for spiked samples of FB1 or FB2 separately, ranging from 84.7 to 93.6%, with a coefficient of variation (CV) of <9.9%. Total time needed for FPIA including sample pretreatment was <30 min. The FPIA was used to screen naturally contaminated maize samples. Results detected by FPIA showed good agreement with that of HPLC-MS/MS with a fit of R(2) = 0.99 for the simultaneous detection of FB1 and FB2. The established method offered a rapid, simple, sensitive, and high-throughput screening tool for the detection of fumonisins in maize.

A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U-(13)C-labeled FB2 and OTA as internal standards. Mixing 20% isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50% and decreased the ion-suppression with 50-75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.

The aim of the present work was to assess the influence of the baking process on the fumonisin content in gluten-free bread. The dough was made using two methods: without sourdough and with sourdough. Fumonisins were determined using high-performance liquid chromatography with ion-trap mass spectrometry. This study showed that the bread baking process caused a statistically significant drop in the mean concentration of free fumonisins: the reduction levels were 30 and 32% for the direct and sourdough-based methods, respectively. The lower reduction after baking was observed for hidden fumonisins: 19 and 10%, respectively. The presence of some compounds (such as proteins or starch) capable of stabilizing fumonisins during the baking process might be responsible for the observed increase in the hidden-to-free ratio from an initial 0.72 in flour to 0.83 in bread made from sourdough and to 0.95 in sourdough-free bread.

We developed a stable isotope dilution assay with liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine multiple mycotoxins in baby foods and animal feeds. Samples were fortified with [(13)C]-uniformly labeled mycotoxins as internal standards ([(13)C]-IS) and prepared by solvent extraction (50% acetonitrile in water) and filtration, followed by LC-MS/MS analysis. Mycotoxins in each sample were quantitated with the corresponding [(13)C]-IS. In general, recoveries of aflatoxins (2-100 ng/g), deoxynivalenol, fumonisins (50-2000 ng/g), ochratoxin A (20-1000 ng/kg), T-2 toxin, and zearalenone (40-2000 ng/g) in tested matrices (grain/rice/oatmeal-based formula, animal feed, dry cat/dog food) ranged from 70 to 120% with relative standard deviations (RSDs) <20%. The method provides sufficient selectivity, sensitivity, accuracy, and reproducibility to screen for aflatoxins at ng/g concentrations and deoxynivalenol and fumonisins at low μg/g concentrations in baby foods and animal feeds, without using conventional standard addition or matrix-matched calibration standards to correct for matrix effects.

Field trials were conducted from 2007 to 2010 to compare grain fumonisin levels among non-Bt maize hybrids and Bt hybrids with transgenic protection against manual infestations of European corn borer (ECB) and Western bean cutworm (WBC). HPLC and ELISA were used to measure fumonisin levels. Results of the methods were highly correlated, but ELISA estimates were higher. Bt hybrids experienced less insect injury, Fusarium ear rot, and fumonisin contamination compared to non-Bt hybrids. WBC infestation increased fumonisin content compared to natural infestation in non-Bt and hybrids expressing Cry1Ab protein in five of eight possible comparisons; in Cry1F hybrids, WBC did not impact fumonisins. These results indicate that WBC is capable of increasing fumonisin levels in maize. Under WBC infestation, Cry1F mitigated this risk more consistently than Cry1Ab or non-Bt hybrids. Transgenically expressed Bt proteins active against multiple lepidopteran pests can provide broad, consistent reductions in the risk of fumonisin contamination.

A fluorescence-based immunochromatographic assay (ICA) for fumonisin B1 (FB1) that employs conjugates of fluorescent microspheres and monoclonal antibodies (FM-mAbs) as detection reporters is described. The ICA is based on the competitive reaction between FB1-bovine serum albumin (BSA; test line) and the target FB1 for binding to the FM-mAb conjugates. A limit of detection (LOD) for FB1 of 0.12 ng/mL was obtained, with an analytical working range of 0.25-2.0 ng/mL (corresponding to 250-2000 μg/kg in maize flour samples, according to the extraction procedure). The recoveries of the ICA to detect FB1 in maize samples ranged from 91.4 to 118.2%. A quantitative comparison of the fluorescence-based ICA and HPLC-MS/MS analysis of naturally contaminated maize samples indicated good agreement between the two methods (r(2) = 0.93). By replacing the target of interest, the FM-based ICA can easily be extended to other chemical contaminants and thus represents a versatile strategy for food safety analysis.

To clarify the changes in rice fumonisin (FUM) concentrations, we conducted field cultivation of 10 forage rice cultivars and inoculation with fumonisin-producing fungal isolates. We cultivated 10 forage rice cultivars at the NARO Institute of Livestock and Grassland Science and one cultivar at two additional farmland sites in Japan in 2011 and 2012. Fusarium fujikuroi, which primarily infects plants shortly after heading, was inoculated on rice just after heading, and we sampled heads at the yellow-ripe and full-ripe stages to assess FUM concentrations. We found differences among cultivars in the FUM concentration and differences among the sites for the same cultivar, but no cultivar had high levels in leaves and stems. Fusarium fujikuroi was the main fumonisin producer. The FUM concentration in heads increases from <1 to 4760 μg/kg DM after the yellow-ripe stage. To control FUM levels, it is necessary to select low-FUM cultivars and manage the cultivation environment.

(18)O labeling is a well-known method for the stable isotope labeling of proteins and peptides. This study describes a modified procedure for using (18)O labeling on small molecules. Fumonisin B1, a worldwide occurring mycotoxin, which is routinely analyzed by HPLC-MS/MS, was chosen as model compound. (18)O labeling was achieved by acid-catalyzed oxygen exchange from H2(18)O. A mixture of different isotopologues was obtained from the exchange, which, however, could be used as an internal standard for HPLC-MS/MS analysis. The identity of the (18)O-labeled fumonisin B1 was confirmed by NMR and HRMS measurements. The applicability as internal standard has been verified by comparison of results obtained from the method described in this paper to results obtained by reference methods. The presented method is of special interest as the (18)O labeling can be generally applied to a large group of small molecules containing carboxylic groups.

A lateral flow dual immunoassay (LFDIA) was developed for rapid quantitative detection of zearalenone (ZEN) and fumonisin B1 (FB1) in corn and wheat samples on a single test strip. Two test lines and the control line on the nitrocellulose membrane were coated with ZEN and FB1 conjugates and goat anti-mouse IgG, respectively. Colloidal gold nanoparticles were conjugated with monoclonal antibodies against ZEN or FB1. The intensity of the test lines was analyzed by a photometric strip reader to determine the concentrations of ZEN and FB1 based on the calibration curves of known concentrations versus intensity readings. Test parameters such as types of buffers, ratio of the two gold-labeled antibodies, and dilution of the sample extracts and the gold-labeled antibodies were optimized. The detection limit was 0.35 and 5.23 ng/mL for ZEN and FB1, respectively, and the corresponding detection ranges were 0.94-7.52 and 9.34-100.45 ng/mL, respectively. Spiked and natural samples were analyzed using both LFDIA and liquid chromatography-tandem mass spectrometry. The two methods had a good correlation (R(2) = 0.96). The dual quantitative LFDIA is sensitive, rapid, and easy-to-use for on-site testing of a large number of samples.

An ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of 34 mycotoxins in dietary supplements containing green coffee bean (GCB) extracts was developed, evaluated, and used in the analysis of 50 commercial products. A QuEChERS-like procedure was used for isolation of target analytes from the examined matrices. Average recoveries of the analytes were in the range of 75-110%. The precision of the method expressed as relative standard deviation was below 12%. Limits of detection (LODs) and limits of quantitation (LOQs) ranged from 1.0 to 50.0 μg/kg and from 2.5 to 100 μg/kg, respectively. Due to matrix effects, the method of standard additions was used to ensure accurate quantitation. Ochratoxin A, ochratoxin B, fumonisin B1 and mycophenolic acid were found in 36%, 32%, 10%, and 16% of tested products, respectively. Mycotoxins occurred in the following concentration ranges: ochratoxin A, <1.0-136.9 μg/kg; ochratoxin B, <1.0-20.2 μg/kg; fumonisin B1, <50.0-415.0 μg/kg; mycophenolic acid, <5.0-395.0 μg/kg. High-resolution mass spectrometry operated in full MS and MS/MS mode was used to confirm the identities of the reported compounds.

Anti-fumonisin B(1) (FB(1)) McAb 1D11 was used as the target for biopanning from a phage random loop-constrained heptapeptide library. After three cycles of panning, seven phages with three mimotope peptides were selected to mimic the binding of FB(1) to 1D11. After the identification of phage ELISA, the phage clone that showed the best linear range of detection was chosen for further research. One peptide with the inserted peptide sequence of the phage was synthetized, named CT-452. An indirect competitive ELISA (peptide ELISA) for detecting FB(1) was established using the CT-452-bovine serum albumin conjugate as coating antigen. The linear range of the inhibition curve was 1.77-20.73 ng/mL. The half inhibitory concentration (IC50) was 6.06 ng/mL, and the limit of detection was 1.18 ng/mL. This method was compared with conventional indirect ELISA (commercial ELISA kit) and high-performance liquid chromatography (HPLC), and the results showed the reliability of the peptide ELISA for the determination of FB(1) in cereal samples. The relationship between the CT-452 and FB(1) standard concentrations in peptide ELISA was evaluated. The results indicated that synthetic peptide CT-452 can replace the FB(1) standard to establish an immunoassay free of FB(1).

This study was designed to investigate the role of hybrids in maize Fusarium section Liseola interaction and fumonisin production, with particular emphasis on the occurrence and accumulation of hidden fumonisins in maize (masking phenomenon). In this 2 year study, naturally infected field crops were chosen with 10 maize hybrids, six of them grown in both years. Maize samples collected in 2010 showed a higher incidence of fungal infection as well as higher fumonisin contamination than those obtained in 2009 but a very similar incidence of F. section Liseola. Fumonisin masking was confirmed in raw maize, with a lower amount of hidden forms as compared to free fumonisins detected in the year with higher contamination. The chemical composition of the different hybrids was determined and correlated with the contamination data: the results obtained highlight the main role of fatty acids, with a higher fumonisin contamination in hybrids showing a higher linoleic acid content and a higher masking action in hybrids with higher oleic to linoleic ratio. These results represent a good basis to explain maize hybrid susceptibility to F. section Liseola infection, fumonisin contamination, and masking not related to a specific commercial hybrid but extendable to all hybrids.

Distiller's dried grains with solubles (DDGS) is a major coproduct of the fuel-ethanol industry and is becoming a popular low-cost ingredient for animal feed. Uncertainties regarding the risk factors in DDGS, such as level of mycotoxins, could limit its application in the animal feed industry. To provide a scientifically sound assessment of the prevalence and levels of mycotoxins in U.S. DDGS, we measured aflatoxins, deoxynivalenol, fumonisins, T-2 toxin, and zearalenone in 67 DDGS samples collected from 8 ethanol plants in the midwestern United States from 2009 to 2011. Among the five mycotoxins, deoxynivalenol was the main focus of the study because the crop year of 2009 was favorable for deoxynivalenol occurrence in corn. We learned that no more than 12% of the samples contained deoxynivalenol levels higher than the minimum advisory level for use in animal feed provided by the U.S. FDA, and the deoxynivalenol levels in all DDGS collected in 2011 were <2 mg/kg. Besides, intensive study showed that the enrichment of deoxynivalenol from contaminated corn to DDGS was about 3.5 times. With regard to the other mycotoxins in DDGS, the study suggested that (1) almost none of the DDGS samples produced in 2010 contained detectable aflatoxins and the highest level of aflatoxins in DDGS was 5.7 μg/kg; (2) no more than 6% of the samples contained fumonisin levels higher than the guidance level for feeding equids and rabbits provided by the U.S. FDA; (3) none of the samples contained T-2 higher than the detection limit; (4) most samples contained zearalenone levels between 100 and 300 μg/kg. This study was based on representative DDGS samples from the U.S. ethanol industry, and the data were collected using state-of-the-art analytical methodology. This study provided a comprehensive and scientifically sound assessment of the occurrence and levels of mycotoxins in DDGS produced from 2009 to early 2011 by the U.S. ethanol industry.

A survey was carried out to determine Fusarium species and fumonisin contamination in 55 durum wheat (Triticum turgidum L. var. durum) samples collected during two harvest seasons (2007 and 2008) using HPLC and further LC-MS/MS confirmation. All samples showed Fusarium contamination with infection levels ranging from 8 to 66%, F. proliferatum being the species most frequently isolated during 2007 and the second most frequently isolated one during the 2008 harvest season, respectively. Natural contamination with fumonisins was found in both harvest seasons. In 2007, 97% of the samples showed total fumonisin (FB(1) + FB(2)) levels ranging from 10.5 to 1245.7 ng/g, while very low levels of fumonisins were detected in samples collected during 2008. These results could be explained by differences in the amount of rainfall during both periods evaluated. A selected number (n = 48) of F. proliferatum isolates showed fumonisin production capability on autoclaved rice. This is the first report of the presence of natural fumonisins in durum wheat grains.

Fumonisin B(2) (FB(2)) was recently found to be produced by Aspergillus niger . When grape-derived products were subsequently analyzed, FB(2) contamination was found in raisins, must, and wine. This study evaluated 681 strains of black aspergilli species isolated from Portuguese wine grapes for FB(2) production when grown on Czapek yeast agar. FB(2) was not detected in Aspergillus carbonarius (n = 75) or Aspergillus ibericus (n = 9) strains, but it was detected in 176 (29%) of the strains belonging to A. niger aggregate (n = 597). The amount of FB(2) produced by these strains ranged from 0.003 to 6.0 mg/kg with a mean of 0.66 mg/kg. The Alentejo region had the lowest percentage (10%) of fumonisinogenic strains, whereas the Douro region had the highest percentage of fumonisinogenic strains (38%). Only 10 strains were found to produce FB(2) and ochratoxin A simultaneously.

Concerns that raisins may be contaminated by fumonisins stem from the persistent occurrence of Aspergillus niger spores on raisins and the recent discovery of fumonisin production by A. niger on grapes, which leads to the widespread occurrence of fumonisin B(2) in wine. This study presents an LC-MS/MS survey of fumonisins in retail raisins. In 10 of 21 brands collected in Denmark, Germany, and The Netherlands, fumonisins B(2) and B(4) were detected at levels up to 13 and 1.3 μg/kg, respectively. Only fumonisin B(2) has been detected in wine, so the presence of fumonisin B(4) in raisins suggests that the fumonisins are produced mainly during the drying process concomitant with the decreasing water activity. Analysis of multiple packages from one manufacturer showed a 3-fold package-to-package variation, suggesting that a few raisins per package are contaminated.

Hidden fumonisins have received great attention in the last years as they have been frequently found in maize products in addition to the free forms. Several papers have shown that interaction with macromolecular components such as protein and starch is at the base of the phenomenon: although the nature of the interaction (covalent or not) is still not clarified, the occurrence of hidden forms is generally revealed by the application of an alkaline hydrolysis procedure. In this study, an in vitro digestion model has been applied to raw maize to evaluate the possible release of hidden fumonisins under gastrointestinal conditions. Upon digestion of the food matrix, an increased amount of total detectable fumonisins was observed in comparison with the analysis on the nondigested matrix, an amount even higher than that calculated through the application of the hydrolysis procedure. Besides the analytical issues, our data have serious implications, since consumers may be exposed to a systematic higher risk than that estimated by conventional techniques.

In this work the presence and migration behavior of mycotoxins formed in sweet pepper, inoculated by Fusarium species involved in internal fruit rot, were investigated. Two different commercial sweet pepper cultivars were inoculated with two different Fusarium proliferatum isolates that were sampled from diseased peppers. After 10 days of incubation at 20 °C in a closed container, the lesion caused by the fungal infection was dissected. Around the lesion, up to three concentric rings of pepper fruit tissue with a width of 5 mm were cut out and analyzed using a multimycotoxin LC-MS/MS method. The analyses resulted in the detection of beauvericin and fumonisins B(1), B(2), and B(3). Beauvericin was detected only in the lesions (95%), and the levels varied between 67 and 73800 μg/kg. Fumonisins B(1), B(2), and B(3) were detected in the lesions and in the surrounding tissue, indicating migration of these toxins into healthy parts of the sweet pepper. In the lesion the fumonisin B(1) level varied between 690 and 104000 μg/kg. Even in the outer ring fumonisin B(1) was still present. Mostly it was present at a lower level than in the lesion, with a maximum level of 556 μg/kg. A similar migration behavior was obtained for fumonisins B(2) and B(3), but lower levels were detected in the lesions, up to 10900 and 1287 μg/kg, respectively. The analysis of 20 pepper samples resulted in the detection of beauvericin or alternariol. Seven samples were contaminated, and the level of beauvericin was 124 μg/kg (N = 1), whereas the level of alternariol varied from below the LOQ (6.6 μg/kg) to 101 μg/kg (N = 6).

In an earlier study using maize seedlings grown from kernels inoculated with Fusarium verticillioides, fumonisin B(1) (FB(1)) was preferentially accumulated in leaf tissue compared to FB(2) and FB(3). The present study tested whether maize seedlings preferentially translocate FB(1) when plants are watered with FB(1) and/or FB(2), without the fungus present. The results show that neither FB(1) nor FB(2) was translocated when administered in the watering solution, and although both FB(1) and FB(2) were taken up by the roots, the accumulation of FB(2) in roots was significantly less than expected, indicating that FB(1) was preferentially accumulated. In addition, there was clear evidence of ceramide synthase inhibition in the roots and sphingoid base and sphingoid base 1-phosphates accumulated in leaf tissue presumably due to translocation from the roots. These findings suggest that the fungus-plant interaction is necessary for FB(1) translocation in maize seedlings infected with F. verticillioides.

Fumonisins are important mycotoxins because they are suspected to cause human and animal toxicoses by the consumption of contaminated corn-based food and feeds. However, with the discovery of fumonisin production in grapes by Aspergillus niger , wine may also be a fumonisin-containing commodity. In the present study, we have developed a simple and quantitative cation-exchange-based purification method for the subsequent isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of fumonisins in wine. A comparative study of seven different solid-phase extraction (SPE) columns showed that polymeric mixed-mode reversed-phase (RP) cation-exchange columns were superior to classic silica-based cation and mixed-mode cation-exchange columns. A total of 77 wine samples from 13 countries were subsequently tested, and surprisingly, 18 (23%) were found to contain fumonisin B(2) in the range of 1-25 microg/L. These findings were further confirmed by immunoaffinity purification and re-analysis of the positive cation-exchanged extracts.

The recent discovery of fumonisin production in Aspergillus niger, raises concerns about the presence of these mycotoxins in grapes and raisins as well as other commodities where A. niger is a frequent contaminant. Here we investigate the potential production of fumonisins in A. niger cultured on grapes and raisins. Sixty-six A. niger, 4 A. tubingensis, and 16 A. acidus strains isolated from raisins were tested for fumonisin production on laboratory media. Neither A. tubingensis nor A. acidus strains produced fumonisins, but 77% of A. niger strains did. None of the strains produced ochratoxin A. Ten selected fumonisin producing A. niger strains were further able to produce fumonisin B(2) and fumonisin B(4) on grapes in the range 171-7841 microg fumonisin B(2)/kg and 14-1157 microg fumonisin B(4)/kg. Four selected strains were able to produce fumonisin B(2) (5-6476 microg/kg) and fumonisin B(4) (12-672 microg/kg) on raisins.

A survey for fumonisins B1 and B2 (FB1 and FB2, respectively) was performed on 180 samples of high-consumption food commodities and 15 feed samples randomly collected from various regions of Tunisia. The determination of fumonisin level was performed by an in-house validated high-performance liquid chromatography and an enzyme-linked immunosorbent assay (ELISA) methods. Detection limit by ELISA for fumonisins sum was 25 microg/kg, and those by HPLC were 50 microg/kg for FB1 and 70 microg/kg for FB2. Recoveries of fumonisins spiked at 130 microg/kg ranged from 68.5 to 75.6% by ELISA, whereas those by HPLC for FB1 at 400 microg/kg and for FB2 at 300 microg/kg varied from 75.2 to 90.5%. Naturally occurring fumonisins were found in 10.5% of food samples with levels ranging from 70 to 2130 microg/kg. All contaminated samples contained FB1, and 31.5% of them contained FB2. In addition, the most contaminated commodities were corn foods and sorghum, whereas no fumonisin contamination was found in any nut or rice samples. For analyzed feed samples, fumonisins were detected in 86.6% of them with concentrations ranging from 50 to 2800 microg/kg. In addition, the performance of analytical methods was investigated in a comparison between ELISA and HPLC results for samples analyzed by both methods.

Fumonisins in maize (Zea mays L.) grain silo bags in the conditions of three Argentine provinces were analyzed to determine how this kind of storage affects contamination and if differential storage durations or times of the year of silo bag closing and opening are factors that could modify it. Moisture content, water activity (a(w)), molds and yeasts present, and fumonisins were analyzed in 163 maize silo bags, at the moment of closing and later at opening. Storage durations ranged from 120 to 226 days. The analysis was centered on fumonisins since most samples were only contaminated with these toxins. Fumonisins, moisture content, and a(w) increased significantly, whereas mold propagules/g and yeasts CFU/g did not present significant differences between silo opening and closing. The date on which silo bags were closed and later opened, however, did affect the level of fumonisin contamination.

The aims of this research were to monitor the presence of fumonisins in maize crops in northern Italy over a 6 year period, to study the role of the cropping system on fumonisin levels, and to contribute to the development of a predictive system for fumonisin contamination. In the 6 year period from 2002 to 2007, 438 maize samples were collected in five regions, supported by agronomic data, and analyzed for fumonisin content. Fumonisin was detected in almost all of the grain samples, but 2007 was less and 2005 more contaminated compared to the other years. Preceding crop, maturity class of hybrids, nitrogen fertilization, sowing and harvest week, and grain moisture significantly affected the level of contamination. The logistic regression developed explained around 60% of variability with major roles for longitude, maturity class, and growing weeks. The function can be used to quantify the effect of these factors in a predictive system.

Mycotoxin and Aspergillus flavus levels in soil-surface corn debris left by no-till agriculture methods (stover, cobs, and cobs with grain) were determined during the December-March fallow period for near-isogenic Bt and non-Bt hybrid corn. By December, average mycotoxin levels in non-Bt corn were many times higher in cobs with grain than in grain harvested in September (total aflatoxins, 774 vs 211 ng/g; total fumonisins, 216 vs 3.5 microg/g; cyclopiazonic acid, 4102 vs 72.2 microg/g; zearalenone, 0.2 vs < 0.1 microg/g). No trichothecenes were detected. Levels of mycotoxins and A. flavus propagules were approximately 10- to 50-fold lower in cobs without grain and stover, respectively, for all mycotoxins except zearalenone. Mycotoxin levels in corn debris fractions decreased during winter but began to rise in March. Levels of all mycotoxins and A. flavus propagules were lower in harvested grain and debris from Bt than non-Bt corn, but differences were significant (p < 0.05) only for aflatoxins.

Under unfavorable climatic conditions, Fusarium spp. can contaminate corn plants in the field and produce toxins that are present at the time of ensiling. The stability of deoxynivalenol, fumonisins B1 and B2, and zearalenone in corn silage was tested over two consecutive years. Variables studied were corn dry matter (DM) and storage length and temperature. The concentration of all Fusarium toxins decreased upon ensiling ( P < 0.001). Increasing the length of storage and ensiling with low DM resulted in a higher rate of toxin disappearance, particularly for the water soluble toxins deoxynivalenol and fumonisin B1. Toxin disappearance ranged from 50% for zearalenone to 100% for deoxynivalenol. In contrast, temperature did not have any effect on stability ( P > 0.05). These results indicate that low DM at ensiling as well as a prolonged storage could be a practical way to reduce or eliminate some Fusarium toxins in contaminated silages.

This study was designed to determine the efficacy of extrusion in reducing fumonisin B1 in corn flaking grits in the presence and absence of glucose. In addition, degradation products of fumonisin B1 during extrusion were identified and quantitated with a mass balance approach. Uncontaminated clean corn grits, grits spiked with 30 microg/g fumonisin B1, and grits fermented with Fusarium verticillioides M-2552 (40-50 microg/g fumonisin B1) were extruded in the presence and absence of glucose (10%, w/w) using a single-screw extruder. Extrusion decreased fumonisin B1 by 21-37%, whereas the same process with added glucose further decreased fumonisin B1 by 77-87%. LC-fluorescence and LC-MS showed that most fumonisin in the extruded samples without added glucose was the fumonisin B1 form, whereas the main degradation product in grits extruded with glucose was N-(deoxy- d-fructos-1-yl)fumonisin B1. The formation of hydrolyzed fumonisin B1 was not significant during extrusion. Results suggest that extrusion in the presence of glucose may reduce fumonisin B1 in corn grits significantly.

Samples from 10 different corn-based food products commercially sold in the Federal District of Brazil were analyzed for fumonisins (FB1 and FB2) using HPLC/fluorescence following naphthalene-2,3 dicarboxaldehyde (NDA) derivatization (limit of quantification (LOQ) = 0.020 mg/kg). Samples were also analyzed for aflatoxins (B1, B2, G1, and G2) on a thin-layer chromatrography (TLC) plate under UV light (LOQ of 2 microg/kg). From the 208 samples analyzed, 80.7 and 71.6% had quantifiable levels of FB1 and FB2, respectively. Mean levels of total fumonisins (FB1 + FB2) ranged from 0.127 mg/kg for corn flakes to 2.04 mg/kg for cornmeal ( creme de milho). No FBs were detected in any of the fresh, sweet corn on the cob samples analyzed. Aflatoxins were not detected in any of the 101 samples analyzed. The daily intakes of fumonisins through the consumption of corn-based food products was estimated using consumption data estimated from the 2002/2003 Brazilian Household Budget Survey and the level of fumonisins found in this and other studies conducted in Brazil. In the Federal District, the calculated total daily intake for the total and the consumers-only populations represented, respectively, 9.0 and 159% of the provisional maximum total daily intake (PMTDI) of 2 microg/kg body weight per day. At the national level, the intakes were calculated based on the fumonisin levels found in the Federal District and on published data from studies conducted elsewhere in the country. They represented 24.1 and 355% PMTDI for the total and the consumers-only populations, respectively. The high incidence of fumonisins in some corn-based products and the exposure levels found for specific subpopulations in the present study indicate the need for setting safe regulatory levels for fumonisins in food in Brazil.

Fusarium moniliforme and Fusarium proliferatum are the most frequently isolated fungi from maize (Zea mays L.) in Spain. Both Fusarium species produce toxins potentially dangerous for animals and humans, the fumonisins being the most significant of those toxins. White maize is preferred for human consumption, and extra care should be taken to avoid kernel mycotoxin contamination. The objectives of this study were to identify and quantify kernel infection by Fusarium spp. and contamination by fumonisin on white maize hybrids, to search for white maize sources of resistance to infection by Fusarium spp. and mycotoxin contamination, and to preliminarily study the genetics involved in such resistances. Ten F(1) single crosses derived from a diallel mating design among five white maize inbreds were evaluated in a randomized complete block design with three replications in 2002 at two locations. Fusarium verticilloides and F. proliferatum were detected on kernels of white maize hybrids cultivated in northwestern Spain. No differences in fungal infection were found among maize genotypes, but differences in fumonisin contamination were significant and could be related, in part, to differences in husk tightness. Among the genotypes studied, general combining ability (GCA) effects were the most important for resistance to fumonisin contamination. Inbreds EP10 and EC22 showed the most favorable GCA effects for husk tightness and fumonisin content, and the cross between them, EP10 x EC22, had the most favorable specific combining ability (SCA) effect for husk tightness. Inbreds EP10 and EC22 showed favorable GCA effects for fumonisin contamination and husk tightness, and the cross EP10 x EC22 was the only one with an average fumonisin level below 1 mug/g. Although this should be confirmed with more extensive studies, white maize inbreds developed from white maize landraces could be sources of resistance to fumonisin contamination.

A total of 52 corn samples collected in 2000 from four main corn production provinces of Iran (Fars, Kermanshah, Khuzestan, and Mazandaran) were analyzed for contamination with Fusarium verticillioides and fumonisins (FB(1), FB(2), FB(3), and 3-epi-FB(3)). The mean incidence of F. verticillioides (percent of kernels infected) for these four areas was 26.7, 21.4, 24.9, and 59.0%, respectively. The incidence in Mazandaran was significantly (p < 0.05) above that of the other areas. All samples from Mazandaran were contaminated with fumonisins with a mean level of total fumonisins of 10674 microg/kg. In contrast, the incidence of fumonisin contamination above 10 microg/kg was 53 (8/15), 42 (5/12), and 57% (8/14) in the samples from Fars, Kermanshah, and Khuzestan, respectively, and the corresponding mean total fumonisin levels were 215, 71, and 174 microg/kg, respectively. No statistical differences (p > 0.05) were observed in the fumonisin levels of the corn samples from these three provinces, which were significantly (p < 0.05) lower than the fumonisin contamination in samples from Mazandaran.

Nineteen dietary and 30 medicinal wild plants used by residents of the Eastern Cape Province of South Africa were investigated for the presence of fumonisin B1 and aflatoxin B1. The plants were extracted in water, and cleanup was undertaken on immunoaffinity cartridges; analysis was by HPLC using fluorescence detection. None of the plant extracts contained detectable levels of aflatoxin B1; however, eight plants, four dietary and four medicinal, were positive for fumonisin B1 at levels ranging from 34 to 524 microg/kg and from 8 to 1553 microg/kg, respectively. The presence of fumonisin B1 was confirmed by LC-MS/MS using positive ion electrospray ionization. Fumonisin B1 provided characteristic fragment ions at m/z 704, 686, 546, 528, 370, and 352 corresponding to sequential loss of H2O and tricarboxylic acid moieties from the alkyl backbone. These results indicate that exposure to fumonisin B1 is much more widespread than initially thought and is the first report of mycotoxin contamination in South African medicinal and dietary wild plants.

A rapid enzyme-linked immunosorbent assay (ELISA) test (microwell plate) and a membrane-based colloidal gold immunoassay in flow-through and lateral-flow formats for the rapid detection of fumonisin B1 (FB1) were developed. The rapid microwell assay can be completed within 20 min with the detection limit of 0.5 +/- 0.2 microg/L. Membrane-based colloidal gold immunoassays had a visual detection limit of 1.0 microg/L for FB1 with the detection time of <10 min. Matrix interference was eliminated by 15-fold dilutions of methanol extracts with buffer. These immunoassays can be used as quantitative or qualitative tools for the rapid detection of FB1 residues in 10-20 min on-site.

The production and consumption of home-brewed Xhosa maize beer is a widespread traditional practice in the former Transkei region of South Africa. HPLC determination of fumonisins B1 (FB1), B2 (FB2), and B3 (FB3) in maize beer samples collected in two magisterial areas, Centane and Bizana, showed a wide range of levels. All samples were positive for FB(1), with a mean level of 281 +/- 262 ng/mL and a range from 38 to 1066 ng/mL. Total fumonisins (FB1 + FB2 + FB3) ranged from 43 to 1329 ng/mL, with a mean of 369 +/- 345 ng/mL. Data on the consumption of home-brewed beer are not available. On the basis of published data for the consumption of commercial beer in South Africa, the fumonisin exposure in these districts among the consumers of maize beer was found to be well above the provisional maximum tolerable daily intake of 2 mug/kg of body weight/day set by the Joint FAO/WHO Expert Committee on Food Additives.

The fumonisin mycotoxins are mainly produced by the fungi Fusarium verticillioides and Fusarium proliferatum, which are both field pathogens of maize. The natural occurrence of fumonisins has been verified in maize and a large range of maize-based products in many countries of the world. However, occasional reports have emerged of fumonisins being detected in wheat, despite the main producing fungi not being pathogens of this cereal. An investigation was conducted into a recent report of the natural occurrence of fumonisins in the 2003/2004 South African wheat crop at levels up to 1.7 mg/kg, as determined by immunoaffinity column cleanup and direct fluorometric measurement. An AOAC International high-performance liquid chromatographic (HPLC) method for the determination of fumonisins in maize was modified and validated for the determination of fumonisins in spiked wheat samples. HPLC analysis of the wheat samples previously found to be positive for fumonisins revealed no detectable (<5 microg/kg) fumonisins in the 30 samples analyzed. These results, which lay doubt on previous reports of fumonisins in wheat, emphasize the fact that screening methods, especially if used outside their range or matrix of applicability, can produce false positive results despite the use of immunoaffinity cleanup. Such results should be validated and confirmed with a more definitive technique.

A total of 205 cornflake samples collected in Belgian retail stores during 2003-2004 were surveyed for the natural occurrence of fumonisin B1 (FB1), B2 (FB2), and B3 (FB3). These cornflake samples, originating from conventional as well as from organic production, were analyzed using an intralaboratory-validated LC-MS/MS method. Additionally, 90 cornflake samples were subjected to rapid screening using a flow-through enzyme immunoassay method to demonstrate the practicability of a screening test coupled to a validated confirmatory LC-MS/MS method for the management of food safety risks. FB(1) concentrations ranged from not detected (nd) [LOD (FB1) = 20 microg/kg] to 464 microg/kg with mean and median concentrations of respectively 104 +/- 113 and 54 microg/kg. For FB2 and FB3, the concentration ranges varied respectively from nd [LOD (FB2) = 7.5 microg/kg] to 43 microg/kg and from nd [LOD (FB3) = 12.5 microg/kg] to 90 microg/kg. Mean concentrations for FB2 and FB3 were respectively 12 +/- 8 and 21 +/- 15 microg/kg, while the median concentration was 11 microg/kg for FB2 and 19 microg/kg for FB3. From the statistical tests (chi2 and ANOVA model III), it could be concluded that the agricultural practice did not have any significant effect on the fumonisin concentrations but that the variation between different batches was significant (p < 0.0001).

The selection of synthetic antibody fragments from large phage libraries has become a common method for the generation of specific antibodies. The technique is particularly valuable when antibodies against small, non-immunogenic molecules (haptens) or highly toxic substances have to be produced. In addition, haptens are usually coupled to protein carriers, bearing the risk that the free hapten is not detectable. Here, a single variable chain antibody (scFv) against the highly toxic mycotoxin fumonisin B1 has been produced. The hapten was coupled via a linker to biotin. Using this conjugate and a naive scFv library, it was possible to circumvent both the necessity of immunization and the risk of a disguised hapten. The scFv obtained after three panning rounds was found to bind specifically to both free fumonisin B1 and fumonisin-biotin conjugate. Also fumonisin B2 was bound by the scFv. Modeling of both scFv and fumonisin B1 molecule revealed a good fitting of structures. The antibody obtained can potentially be used for developing a rapid and affordable immunoassay for detection of food contamination and can be applied in immunoaffinity chromatography, usually carried out prior to HPLC analysis of mycotoxin-contaminated food and feed.

Essential oils extracted by hydrodistillation from local plants in Benin, western Africa, and oil from seeds of the neem tree (Azadirachta indica) were evaluated in vitro and in vivo for their efficacy against Fusarium verticillioides infection and fumonisin contamination. Fumonisin in corn was quantified using a fluorometer and the Vicam method. Oils from Cymbopogon citratus, Ocimum basilicum, and Ocimum gratissimum were the most effective in vitro, completely inhibiting the growth of F. verticillioides at lower concentrations over 21 days of incubation. These oils reduced the incidence of F. verticillioides in corn and totally inhibited fungal growth at concentrations of 8, 6.4, and 4.8 microL/g, respectively, over 21 days. At the concentration of 4.8 microL/g, these oils did not affect significantly fumonisin production. However, a marked reduction of fumonisin level was observed in corn stored in closed conditions. The oils adversely affected kernel germination at 4.8 microL/g and therefore cannot be recommended for controlling F. verticillioides on stored corn used as seeds, when used at this concentration. The oil of neem seeds showed no inhibitory effect but rather accelerated the growth of F. verticillioides.

Four small tortilla plants were visited in Cameron County, Texas, where observations were made on their production methods. Samples of liquids and solids were collected at each stage of the nixtamalization process, and the pH was recorded. Samples were analyzed for fumonisin B(1) (FB(1)) using an immunoaffinity column/HPLC method chosen for its sensitivity for FB(1). It was found that production methods were highly variable among the producers visited, with major differences particularly in the amount of lime added and boiling times. As reported by others working in Mexico and Central America, FB(1) was found in some tortillas. This led to studies of the effects of the various recipes and across a greater range of initial FB(1) concentration/damaged corn than has typically been reported. Five initial concentrations of FB(1) were tested using irradiated corn kernels inoculated with Fusarium verticillioides MRC 826 as the source of FB(1). The amount of FB(1) detected in the masa and tortillas decreased as the concentration of Ca(OH)(2) increased, and boiling time had no apparent effect. Unexpectedly, as the initial concentrations were increased in the corn prior to nixtamalization, greater percentage reductions in FB(1) were observed.

Fumonisins were monitored in corn grain collected from Bt hybrids grown in 107 locations across the United States in 2000-2002. Bt corn hybrids contain the Cry1Ab protein from Bacillus thuringiensis that controls European corn borers and other stalk-boring pests. Fumonisin levels were frequently lower in grain from Bt hybrids grown in field trials under conditions of natural (FACT trials) or manual insect infestation (university trials). Over three years of FACT trials, there were 126/210 comparisons when fumonisin levels in grain from control hybrids were >2 ppm, exceeding U.S. FDA guidance levels of 2 ppm for human food. Grain from Bt hybrids was at or below 2 ppm of fumonisins for 58 of the 126 comparisons. The use of Bt hybrids can increase the percentage of corn grain that would be suitable for use in food and feed.

Corn silage was dried, ground, and then extracted with 0.1 M ethylenediaminetetraacetic acid. The filtrate was applied to a FumoniTest immunoaffinity column. Fumonisins were derivatized with naphthalene-2,3-dicarboxaldehyde, separated on a C(18) liquid chromatographic column, and detected by fluorescence. The detection limits for fumonisin B(1), fumonisin B(2), and fumonisin B(3) were 50, 25, and 25 ng/g of dried silage, respectively. Recoveries of fumonisin B(1), fumonisin B(2), and fumonisin B(3) from wet and dried corn silage spiked over the range of 100-5000 ng/g averaged 91-106%. The method was applied to corn silage samples collected from the midwestern area of the United States during 2001-2002. Of 89 corn silage samples, fumonisin B(1), fumonisin B(2), and fumonisin B(3) were found in 86 (97%), 64 (72%), and 51 (57%) of the samples. The mean positive levels of fumonisin B(1), fumonisin B(2), and fumonisin B(3) were 615, 93, and 51 ng/g, respectively, in dried silage. This suggests that fumonisins may be frequent low level contaminants in corn silage.