Influence of the industrial process from caryopsis to cornmeal semolina on levels of fumonisins and their masked forms

The influence of cornmeal industrial production processing on the distribution of fumonisins in the various different production chain corn derivatives (corn, corn flour, germ, middlings, broken corn, cornflake and cornmeal flour)was studied.Free and hydrolyzed fumonisin fractions were extracted and their content was determined by HPLC-MS/MS analysis. Results showed that fumonisin amounts decreased significantly after cleaning and corn-flaking processes, achieving a final reduction of about 40% in the cornmeal semolina, while higher level of contamination in corn flour (fumetto) and middlings were detected. Furthermore, in order to better understand the influence of the different treatments on fumonisin distribution, the occurrence of their free and masked forms during this industrial processing was investigated.Results for masked fumonisins showed that they were not detected probably due to different climatic and technological factors.     

Natural mycotoxin contamination of maize (Zea mays L.) in the South region of Brazil

The natural co-occurrence of fungal metabolites in maize samples from the South region of Brazil was studied using an LC-MS/MS based multi-mycotoxin method. All maize samples (n = 148) were contaminated with fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂). Aflatoxin B₁ (AFB₁) and aflatoxin G₁ (AFG₁) were detected in 38 and 11 samples, respectively, while zearalenone (ZEN) and deoxynivalenol (DON), which were first regulated in 2014, were found in 110 and 71 samples, respectively. Apart from regulated mycotoxins, a broad range of non-regulated metabolites, from Aspergillus, Fusarium, Alternaria, Penicillium and other microbes, were also detected in maize sample. Fusarin C, a possible carcinogenic compound to humans, produced by Fusarium species and not addressed by Brazilian legislation, was detected in 54.2% of maize samples. All analysed maize samples were found to be contaminated by at least ten different metabolites, with the largest number of metabolites found in the same sample being 51.     

Distribution of deoxynivalenol and zearalenone in milled germ during wheat milling and analysis of toxin levels in wheat germ and wheat germ oil

A method consisting of solvent extraction using hexane for defatting, multifunctional cleanup column, and HPLC determination was validated for the analysis of deoxynivalenol (DON) and zearalenone (ZEA) in wheat germ and wheat germ oil. A total of 36 batches of grain wheat were subjected to industrial milling and the distribution factors in milled germ were 47% for DON and 71% for ZEA. A survey of 50 samples of germ-based dietary supplements revealed that 60% of wheat germ and 40% of wheat germ oils contained DON at mean values of 111 and 41 μg/kg, respectively, while none of germ samples and 16% oils contained ZEA (mean 6 μg/kg). Contamination levels lead to a daily intake of 1.3 μg DON and 0.03 μg ZEA, representing 1.9% and 0.23% of their respective tolerable daily intakes (TDI).     

Mycotoxins in maize grains grown in organic and conventional agriculture

Maize is traditionally used for bakery in several countries, and autochthonous varieties are increasingly demanded particularly for organic agriculture, but one of the dangers of cereal consumption is mycotoxin contamination. Mycotoxins are dangerous for health and might be present in any grain depending on genotypes and environments. In the present work we assess the natural levels of fumonisin and deoxynivalenol (DON) contaminations in nine diverse open-pollinated maize varieties grown in four different locations, under organic or conventional conditions, in two regions from the humid Spain during two years. Differences were significant among locations and among varieties for fumonisin contamination but not for DON content. Locations were the main environmental source of variation affecting fumonisins while DON was more affected by years. The Basque locations had more fumonisin than the Galician locations, but there were no differences between organic and conventional environments. Fumonisin contamination was more variable than DON among locations and among varieties. Fumonisin and DON were highly correlated on average but correlations were low for each particular environment. Mean fumonisin and DON were below the threshold allowed by the EU, but the white-kernel medium late variety Rebordanes(P)C2 had more than 4.00 mg/kg of fumonisin in one location, while the early yellow variety Sarreaus had the lowest contamination. We conclude warning producers of the danger of natural contamination with mycotoxins for some varieties in specific environments.     

An ultrasensitive gray-imaging-based quantitative immunochromatographic detection method for fumonisin B1 in agricultural products

Fumonisins (FBs) are widely found in rice, maize, peanut, wheat, and other agricultural products. These have been detected using a chromatography technique, whereas the rapid assay by a highly sensitive monoclonal antibody is minimally reported. Herein, a highly sensitive monoclonal antibody (7A11) was successfully developed by hybridoma technique. The 50% inhibition concentration (IC₅₀) of 7A11 monoclonal antibody was 0.32 ng/mL in an optimized buffer. The cross-reactivity between fumonisin B₁ and fumonisin B₂, B₃ was 4.3% and 12.8%, respectively. Based on the newly developed 7A11 antibody, a high sensitivity indirect competitive enzyme-linked immunosorbent assay (icELISA) and gold nanoparticles-based gray imaging quantification immunoassay (GNPs-GI) were established. The analytical range of icELISA was 0.08–1.38 ng/mL and that for GNPs-GI was 0.24–15 ng/mL. Both the methods showed adequate recoveries (80.0–105.8% for icELISA and 78.5–115.2% for GNPs-GI) in spiked samples. Compared to high-performance liquid chromatography (HPLC), icELISA and GNPs-GI indicated reliability that could be used for further detection of fumonisin B₁ in agricultural products.     

Impact of Pediococcus pentosaceus strain L006 and its metabolites on fumonisin biosynthesis by Fusarium verticillioides

The aim of this work was to study the effectiveness of a Pediococcus pentosaceus strain L006, isolated from maize leaf and previously characterised for its high antifungal efficiency, on fumonisin biosynthesis by Fusarium verticillioides. Studies performed in GYEP medium supplemented with amylopectin showed a significant increase in fumonisin production when the F. verticillioides strain was simultaneously co-inoculated with the P. pentosaceus strain or inoculated in a three-day-old culture of this lactic acid bacteria. Our studies also demonstrated that some extracellular metabolites produced in MRS medium by the P. pentosaceus strain L006 were able to significantly reduce fumonisin production in liquid medium as well as on maize kernels. Fumonisin yields by F. verticillioides inoculated on autoclaved maize kernels were reduced by a factor ranging from 75% to 80% after 20 days of incubation. Our results illustrate the potential risk linked to the use of an antagonistic bacterial agent to manage fumonisin contamination, while emphasizing the potential use of bacterial metabolites to counteract fumonisin accumulation in kernels.     

Effect of cleaning,sorting and milling processes in wheat mycotoxin content

Mycotoxins are a ubiquitous contaminant and are difficult to prevent or to diminish; it is, therefore, important to establish the contributions of processing steps to eliminating mycotoxins in the production of safer foods. The objective of this study was to investigate the effects of wheat cleaning, sorting, and milling processes on Fusarium mycotoxin distribution in two naturally contaminated wheat cultivars. The study focused on evaluating the effects of first-stage processing methods, cleaning, and gravity separator, on wheat mycotoxin content. The distribution of Fusarium mycotoxins was analyzed after two milling processes. Firstly, a Laboratory Mill 3100 was used to obtain the whole milled wheat. Secondly, a pilot-scale mill Quadrumat Senior was used to get wheat milled fractions (finished flour and bran). Wheat samples (BRS Parrudo and BRS 374) were collected during the 2014 season that were highly vulnerable to Fusarium outbreaks in Southern Brazil. Fusarium toxin (DON, 3-ADON, 15-ADON, NIV, and ZON) levels were determined for all milled fractions via chromatography (UHPLC-MS/MS). The cleaning and sorting methods employed post-harvest significantly reduced the mycotoxin content in wheat. The reduction of mycotoxin was progressive through each processing method, and the gravity separator equipment resulted in the lowest contamination levels in products intended for human consumption for both cultivars. Through the milling process, the DON contamination in finished flour was significantly lower than in milled wheat; however, there were no significant differences in contamination between the milled wheat and bran. The cleaning and sorting methods for both wheat cultivars generated safer foods when compared with unsorted wheat samples (BRS Parrudo and BRS 374).     

Estimation of dietary intakes of fumonisins B1 and B2 from conventional and organic corn

The dietary intakes of fumonisins from 60 samples of conventional and organic corn were assessed. A 13.3% of the conventional corn samples contained fumonisin B₁ and B₂ at mean levels of 43 and 22 ng/g, respectively, while 10% of the organic corn samples contained fumonisins at somewhat lower levels of 35 ng/g (FB₁) and 19 ng/g (FB₂). Overall, the fumonisin levels in the corn samples were much lower than the maximum level of 2000 ng/g (as the sum of FB₁ and FB₂) proposed for unprocessed maize in a recent EU regulation. The fumonisins present in conventional and organic maize are estimated to contribute with very low percentages of 0.21% and 0.17%, respectively, to the level considered at risk for human health. Based on the data exposed in this paper, the farming system is probably not of decisive importance for the final contamination of agricultural products with these mycotoxins.     

Prevalence of Campylobacter in chicken and chicken by-products retailed in Sapporo area,Hokkaido, Japan

The present work was carried out to study the prevalence of Campylobacter in fresh chicken meat and chicken by-products on retail level in Sapporo, Japan. Out of the 170 samples of chicken meat (breasts and thighs) and chicken by products (wings, livers, gizzards and hearts), 110 (64.7%) were contaminated with Campylobacter. Among the different products, chicken wings showed the highest contamination incidence (77.1%) followed by chicken thighs (70%), while chicken gizzards and hearts showed the lowest contamination incidence (45% and 40%, respectively). Of the 341 Campylobacter isolates, 278 (81.5%) were identified as Campylobacter jejuni and 63 (18.5%) isolates were identified as C. coli. All of the 341 Campylobacter strains identified by the conventional culture methods were further confirmed by polymerase chain reaction (PCR), which indicated that almost all (99.4%) of the tested strains were also positive by PCR. Screening of 195 selected Campylobacter isolates for determining their antimicrobial resistance indicated that most of the tested strains (73.3%) were resistant to three or more of antimicrobials examined. The study concluded that high proportion of chicken meat and chicken by-products marketed in Sapporo area are contaminated by Campylobacter, most of which are antimicrobial-resistant strains, with a possible risk from such microorganism especially from consumption of undercooked or post-cooking contaminated chicken products.     

Fumonisins and their masked forms in maize products

In recent years many papers on masked mycotoxins in maize-based products appeared, including reports on fumonisins capable to form non-covalent bonds with food macro constituents. Such so-called “hidden fumonisins” are frequently present in food at quantities higher than the free forms. The aim of this work was to assess levels of free and total (free + hidden) fumonisins (B₁, B₂ and B₃) in 88 maize products available on the Polish retail market. Isotope dilution ion trap mass spectrometery coupled to a high performance liquid chromatography was used. 57% of all tested samples contained free fumonisins at concentrations above our limit of quantification LOQ (mean 390 ± 676 μg/kg). More than 77% of the samples contained free + hidden fumonisins at concentrations above LOQ (mean 574 ± 1177 μg/kg). The highest mean fumonisins concentrations 1006 ± 1131 μg/kg, 1651 ± 2317 μg/kg, respectively for free and free + hidden forms were observed in the group of maize snacks. The lowest fumonisin concentrations were found in maize-based starch concentrate products. None of the tested products within that group had free fumonisins concentrations above LOQ, while mean concentration of free + hidden fumonisins was as low as 82 ± 42 μg/kg. In thermally processed products like corn flakes and various snacks the hidden-to-free fumonisin concentration ratio was higher than in unprocessed products like flour, groats or raw popcorn grains.     

Fate of ochratoxin A during wheat milling and some Chinese breakfast processing

To estimate the dietary intake of ochratoxin A (OTA), information on the fate during wheat processing is needed. The wheat contaminated with OTA at both levels (93.22 and 248.93 μg/kg) was artificially inoculated by Aspergillus ochraceus. Concentrations of OTA were 1.43–1.66 times higher in bran than whole wheat and 1.27–1.50 times higher in shorts than bran. A concentration reduction of 43.29–55.16% for OTA in flour was observed, with the final concentrations of 41.80 and 138.33 μg/kg in flour respectively. Whereas, OTA was not transferred or decomposed during milling, as the total amount of OTA in all milling fractions didn't decreased. The further losses of OTA were various depending on different processes. The concentration of OTA increased by 11–16% when the flour was processed into Chinese steamed bread (CBS), with the OTA concentrations of 49.2 and 161.35 μg/kg in CBS. It revealed fermentation and steaming increased the OTA levels in CBS. The loss of OTA was small in the Chinese fried bread sticks (CFBS) (38.84 and 129.02 μg/kg), being of 6.73–9.63%. A higher reduction of 23.27–23.92% for OTA was detected in the noodles processing, with the final concentration of 32.98 and 108.24 μg/kg in noodles respectively. The result revealed that the temperature, pH values and strains involved the processes exerted different effects. High temperature (180 °C) and alkaline condition (pH > 7) facilitated to the removal of OTA, while fermentation (with dry yeast) increased the OTA levels in products.     

Fumonisin occurrence in naturally contaminated wheat grain harvested in Argentina

A survey was carried out to determine fumonisin contamination in 135 common and 40 durum wheat samples collected during 2011 harvest season (non-FHB epidemic year) in the main wheat production area of Argentina using LC–MS/MS. A 93% of total samples showed fumonisin contamination, with levels ranging from 0.16 to 680.44 ng/g in common and from 0.15 to 1304.39 ng/g in durum wheat samples, respectively. FB₁ was the fumonisin most frequently found during the evaluated year. Twenty five wheat samples (15 common and 10 durum) were selected for a deoxynivalenol (DON) analysis among all the samples analyzed for fumonisin content using different contamination levels as selection criteria. DON contamination was present in 24 out of 25 wheat samples, the levels ranging from 50.60 to 28650 ng/g. Nine out of 25 wheat samples reached values higher than 1000 ng/g. However there was no correlation between fumonisin and DON contamination. This is the first report of natural fumonisin presence in common wheat grains in Argentina, as well as of DON co-occurrence in both types of wheat.     

Mycotoxin occurrence in grains and the role of postharvest management as a mitigation strategies. A review

Mycotoxins are poisonous compounds produced by certain species of fungi found in contaminated grain. There are five major groups of mycotoxins which can occur in grains: Aflatoxin, fumonisin, deoxynivalenol (DON), ochratoxin (OT), and zearalenone (ZEN). Their occurrence may start in the field, harvesting, handling, storage, and processing. DON, ZEN, and fumonisins may start to cause the grains at the field/or pre-harvest while aflatoxin and OT are mostly occurring during storage due to improper postharvest handling. Most of the grains susceptible to mycotoxins such as maize, peanut/groundnut, sorghum, millet, wheat, and rice were reviewed. The main postharvest factors for the cause of grain mycotoxin contamination are mechanical injury, insect infestation, time of harvesting, drying method, types of storage structure and conditions, handling and processing. Temperature, moisture and humidity are the main factors for the growth and development of mycotoxins. Developing countries especially African are more vulnerable for the causes due to lack of well-established infrastructures, regulations, and standards. Postharvest mitigation strategies are an important and cost-effective method to control the cause. The core grain postharvest interventions used as mitigating strategies of mycotoxin includes rapid and proper drying, postharvest insect control, proper transportation and packaging, good storage conditions, use of natural and chemical agents and irradiation. Grain processing such as sorting, cleaning, milling, fermentation, baking, roasting, flaking, nixtamalization and extrusion cooking are also reported to reduce mycotoxin concentration. In general, system approach to good manufacturing practice and HACCP based implementation are important to mitigate mycotoxins in grains.     

Free and hidden fumonisins in Brazilian raw maize samples

Fumonisins are secondary metabolites produced primarily by fungi strains that belong to the genera Fusarium and Alternaria, which have been shown to be highly prevalent in maize crops. Some authors have documented the presence of hidden forms of fumonisins occurring in raw maize. This purpose of this study was to determine the occurrence of free and hidden fumonisins in raw maize. The concentrations of fumonisins in 72 naturally contaminated maize samples were analyzed using liquid chromatography coupled to mass spectrometry. The performance parameters of the method to determine free fumonisins forms (FB₁ and FB₂) and hydrolyzed fumonisins forms (HFB₁ and HFB₂) were evaluated using the standards from the Commission of the European Communities (Commission, 2002). The analytical methods employed fell within the established guidelines. The amount of total fumonisins measured based on the hydrolyzed forms (HFB₁ + HFB₂) was 1.5–3.8 times greater than the amount of free fumonisins (FB₁ + FB₂). The concentration of hidden fumonisins was calculated by subtracting the levels of free fumonisins from the total fumonisin levels. The levels of hidden fumonisins were calculated to be 0.5–2.0 times greater than the level of free fumonisins. A strong positive correlation (R = 0.97) was observed between free fumonisins (FB₁ + FB₂) and. total fumonisins (HFB₁ + HFB₂). Based on this correlation, a predictive model was generated to estimate the total fumonisin level based on the measured/reported free fumonisin concentration. These results show that the risk of exposure to fumonisins is likely underestimated if only free fumonisins are considered. However, the predictive model could be a novel approach to estimating the total amount of fumonisins in maize samples without needing to perform expensive and time-consuming analytical methods.     

Enumeration and characterization of Listeria monocytogenes in novelty ice cream samples manufactured on a specific production line linked to a listeriosis outbreak

Listeriosis is an invasive illness typically caused by the ingestion of foods contaminated with Listeria monocytogenes. In 2015, an outbreak of listeriosis was linked to ice cream products produced on a specific production line at Facility X. The United States Food and Drug Administration (FDA) obtained samples representing several lots of three products manufactured on that line from May 2014 through January 2015. Two of these products, A and B, while not linked to any reported illnesses, were analyzed to determine the frequency of contamination and the contamination level for risk assessment and dose-response analyses. These enumerations were performed utilizing a Most Probable Number (MPN) method, with a lower detection limit of 0.03 MPN/g, on 344 samples of Product A and 95 samples of Product B. Ten lots of Product A were analyzed and 77% of the samples tested were found to be positive for L. monocytogenes. Five lots of Product B were analyzed and 46% of the tested samples were found to be positive. Additionally, the level of contamination of positive Product B samples was always less than 1 MPN/g. The contamination levels of both products, overall, were low with median values of 0.1 MPN/g and 0.02 MPN/g for Products A and B, respectively. A majority of Product A samples (52%) were contaminated at levels of less than 1 MPN/g and only one sample was above 100 MPN/g. Whole genome sequencing (WGS) of L. monocytogenes isolated from ice cream samples produced in the line suggested minor strain differences related to product type, possibly due to differences in the food matrices and/or differences in the manufacturing equipment. Overall, the data showed a consistent low level of contamination in products produced from a single production line over a nine month period.     

Multi-spectral kernel sorting to reduce aflatoxins and fumonisins in Kenyan maize

Maize, a staple food in many African countries including Kenya, is often contaminated by toxic and carcinogenic fungal secondary metabolites such as aflatoxins and fumonisins. This study evaluated the potential use of a low-cost, multi-spectral sorter in identification and removal of aflatoxin- and fumonisin-contaminated single kernels from a bulk of mature maize kernels. The machine was calibrated by building a mathematical model relating reflectance at nine distinct wavelengths (470–1550 nm) to mycotoxin levels of single kernels collected from small-scale maize traders in open-air markets and from inoculated maize field trials in Eastern Kenya. Due to the expected skewed distribution of mycotoxin contamination, visual assessment of putative risk factors such as discoloration, moldiness, breakage, and fluorescence under ultra-violet light (365 nm), was used to enrich for mycotoxin-positive kernels used for calibration. Discriminant analysis calibration using both infrared and visible spectra achieved 77% sensitivity and 83% specificity to identify kernels with aflatoxin >10 ng g⁻¹ and fumonisin >1000 ng g⁻¹, respectively (measured by ELISA or UHPLC). In subsequent sorting of 46 market maize samples previously tested for mycotoxins, 0–25% of sample mass was rejected from samples that previously tested toxin-positive and 0–1% was rejected for previously toxin-negative samples. In most cases where mycotoxins were detected in sorted maize streams, accepted maize had lower mycotoxin levels than the rejected maize (21/25 accepted maize streams had lower aflatoxin than rejected streams, 25/27 accepted maize streams had lower fumonisin than rejected streams). Reduction was statistically significant (p < 0.001), achieving an 83% mean reduction in each toxin. With further development, this technology could be used to sort maize at local hammer mills to reduce human mycotoxin exposure in Kenya, and elsewhere in the world, while at once reducing food loss, and improving food safety and nutritional status.     

Network and vulnerability analysis of international spice trade

The spice trade network is one of the oldest and substantially vulnerable systems of the agri-food supply chains. Based on statistical analysis of spice paprika (chilli red pepper) and black pepper trade flows within the EU member states, stochastic simulation models have been developed for prognosis of the proliferation of contaminated products between the member states as a function of the source-state of the contaminated products. Results highlight the rapidity of proliferation, and offer a simple, but robust tool for prediction of contamination patterns among states, serving the formation of a targeted defence strategy and policy Traditional geostatistical methods (e.g. Morens’ I of spatial autocorrelation) in most cases are not suitable to predict the geographic distribution of contaminated products among countries, due to complexity and inter-connectedness of the European spice network. The pattern of proliferation of contaminated products between member states was analysed using a dyadic network of relational data, applying additive and multiplicative effects model. Results of analysis prove the importance of long-distance, international trade in distribution of contaminated products.     

Multi-mycotoxins analysis in ginger and related products by UHPLC-FLR detection and LC-MS/MS confirmation

The aim of this study was to optimize and validate a powerful method for the simultaneous analysis of aflatoxins B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁), G₂ (AFG₂) and ochratoxin A (OTA) in ginger and related products collected from local markets in Beijing, China. The optimized analytical procedure was based on immunoaffinity column (IAC) clean-up, followed by ultra-high performance liquid chromatography with fluorescence (UHPLC-FLR) detection. Limits of detection (LOD) and quantification (LOQ) for the five mycotoxins were 0.005–0.2 and 0.0125–0.5 μg kg⁻¹, respectively. The average recoveries ranged from 84.2 to 97.3% with relative standard deviations (RSDs) from 0.63 to 7.86% at three spiking levels. Good linearity was observed for the analytes with correlation coefficients all higher than 0.9995. The established method was applied to 30 samples of 10 different species of ginger and related products, and all positive samples were confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The results showed that 5 samples of ginger products were contaminated with AFB₁ at 0.13–1.38 μg kg⁻¹, while 3 samples of ginger and 2 samples of ginger products were contaminated with OTA at 0.31–5.17 μg kg⁻¹. All the contamination levels were below the legally allowable limits.     

Concentration of ochratoxin A in breakfast cereals and snacks consumed in the United States

A total of 144 breakfast cereal and snack samples collected from six areas in the United States (U.S.) were surveyed for the presence of ochratoxin A (OTA). All samples are the processed products including mainly corn, oat, wheat, and rice. The analytical methods in this study were immunoaffinity columns (IAC) and high performance liquid chromatography (HPLC) with fluorescence detection (FLD). The method provided recoveries of OTA from all sample matrices in the range of 95–100%. The limits of detection and limits of quantification for OTA were 0.032 and 0.10 ng/g for corn, wheat, and rice based samples; 0.038 and 0.12 ng/g for oat based samples, respectively. Analytical results showed that 75 samples (52%) were contaminated with OTA in the range of 0.10 and 7.43 ng/g. Among the OTA contaminated samples, 40% were labeled as organic and 60% were conventional with mean concentrations of 1.21 and 1.07 ng/g, respectively. There were ten contaminated samples, all from oat based products, exceeding the maximum limits for OTA by European Commission Regulation (3 ng/g) in cereal based products.     

Control of Fusarium moulds and fumonisin B1 in seeds by gamma-irradiation

The distribution of naturally occurring Fusarium moulds producing fumonisin B₁ in seeds was determined. Fusarium infection of seed samples ranged from 10% to 60%, Fusarium moniliforme was the predominant species. Fusarium counts in wheat seeds were 8.1 × 10⁴ CFU/g, 6.3 × 10⁶ CFU/g in maize and 4.8 × 10³ CFU/g in barley. Wheat, maize and barley seeds naturally contaminated with varying levels of fumonisin B₁ 1.4–5.8, 8.0–13.8 and 0.1–0.5 μg/g, respectively. F. moniliforme and Fusarium proliferatum were major Fusarium contaminants producing fumonisin B₁. The effect of gamma irradiation on Fusarium moulds and levels of fumonisin B₁ was also determined. The viable counts of Fusarium in seeds decreased by increasing the radiation dose levels and the growth of Fusarium spp. was inhibited at 4.0 kGy for barley and 6.0 kGy for wheat and maize. Application of radiation dose at 5 kGy inactivated fumonisin B₁ by 96.6%, 87.1% and 100% for wheat, maize and barley, respectively, and a dose of 7 kGy was sufficient for complete destruction of fumonisin B₁ in wheat and maize.