Factors associated with fumonisin contamination of maize in Uganda

BACKGROUND: During production and handling, maize is attacked by many Fusarium species, some of which are prolific producers of fumonisins. Contamination of maize with fumonisins is influenced by climate, agronomic and postharvest practices. This study investigated the factors associated with the occurrence of fumonisins in maize produced in three agroecological zones of Uganda. RESULTS: All the maize samples were positive for fumonisins with levels ranging from 0.27 to 10 mg kg^?1. A positive and significant correlation (P < 0.01) was observed between fumonisin levels and agroecological zone. Maize from high altitude zone had significantly higher (P < 0.05) mean total fumonisin content (4.93 mg kg^?1) than maize from the mid altitude‐moist (4.53 mg kg^?1) and mid altitude‐dry (4.50 mg kg^?1) zones. Five farmer practices, namely intercropping, crop rotation, delayed harvesting, drying maize on bare ground and planting treated seeds were significantly associated with fumonisin production in maize. Intercropping, delayed harvesting and drying maize on bare ground increased fumonisin contamination whereas crop rotation and planting treated seeds reduced the contamination. CONCLUSION: All maize samples obtained from the three agroecological zones were contaminated with fumonisins. The study showed that some of the farmers' practices predispose maize to fumonisin contamination. The findings are important for future studies aimed at designing strategies to control and prevent contamination of maize with fumonisins. Copyright © 2009 Society of Chemical Industry     

Simple intervention method to reduce fumonisin exposure in a subsistence maize-farming community in South Africa

In the Centane magisterial area of South Africa, high rates of oesophageal cancer have been associated with home-grown maize contaminated with fumonisins. The aim of this study was to implement a simple intervention method to reduce fumonisin exposure in a subsistence-farming community. The hand-sorting and washing procedures, based on traditional maize-based food preparation practices, were previously customised under laboratory-controlled conditions. Home-grown maize and maize-based porridge collected at baseline were analysed for fumonisin B₁, B₂ and B₃. The geometric mean (95% confidence interval) of fumonisin contamination in the home-grown maize at baseline was 1.67 (1.21–2.32) mg kg^?1 and 1.24 (0.75–2.04) mg kg ^?1 (dry weight) in the porridge. Fumonisin exposure was based on individual stiff porridge consumption and the specific fumonisin levels in the porridge (dry weight) consumed. Porridge (dry weight) consumption at baseline was 0.34 kg day^?1 and fumonisin exposure was 6.73 (3.90–11.6) µg kg^?1 body weight day^?1. Female participants (n = 22) were trained to recognise and remove visibly infected/damaged kernels and to wash the remaining maize kernels. The discarded kernels represented 3.9% by weight and the fumonisins varied from 17.1 to 76.9 mg kg^?1. The customised hand-sorting and washing procedures reduced fumonisin contamination in the maize and porridge by 84 and 65%, respectively. The intervention reduced fumonisin exposure by 62% to 2.55 (1.94–3.35) µg kg^?1 body weight day^?1. This simple intervention method has the potential to improve food safety and health in subsistence-farming communities consuming fumonisin-contaminated maize as their staple diet.     

Co-occurrence of fumonisins with aflatoxins in home-stored maize for human consumption in rural villages of Tanzania

This study determined maize-user practices that influence the presence of fumonisin and aflatoxin contamination of maize in food consumed in the rural areas of Tanzania. Samples of the 2005 maize harvest in Tanzania were collected from 120 households and examined for fumonisins and aflatoxins. Information on whether the maize was sorted to remove defective (visibly damaged or mouldy) maize before storage and whether the damaged and mouldy maize or the non-dehulled maize was used as food was also collected. In addition, the percentage of defective kernels in the samples was determined. Ninety per cent of the households sorted out defective maize, 45% consumed the defective maize and 30% consumed non-dehulled maize. In 52% of the samples fumonisins were determined at levels up to 11,048 µg kg^?1 (median = 363 µg kg^?1) and in 15% exceeded 1000 µg kg^?1; the maximum tolerable limit (MTL) for fumonisins in maize for human consumption in other countries. Aflatoxins were detected in 18% of the samples at levels up to 158 µg kg^?1 (median = 24 µg kg^?1). Twelve per cent of the samples exceeded the Tanzanian limit for total aflatoxins (10 µg kg^?1). Aflatoxins co-occurred with fumonisins in 10% of the samples. The percentage defective kernels (mean = 22%) correlated positively (r = 0.39) with the fumonisin levels. Tanzanians are at a risk of exposure to fumonisins and aflatoxins in maize. There is a need for further research on fumonisin and aflatoxin exposure in Tanzania to develop appropriate control strategies.     

Management of fumonisin contamination in maize kernels through the timing of insecticide application against the European corn borer Ostrinia nubilalis Hübner

The European corn borer (ECB), Ostrinia nubilalis, is the principal pest of maize in Central and South Europe. It is known to promote Fusarium verticillioides infection in maize grain, a recognized producer of fumonisins. Field experiments were performed in 2006 and 2007 in two sites in NW Italy to determine the effects of the timing of insecticide application on ECB damage, fungal ear rot and fumonisin contamination under natural conditions. Different insecticide application timings were compared, from maize flowering to approximately 15 days after the flight peak of adult ECB. At harvest, the ears were rated for incidence and severity of ECB damage, fungal ear rot symptoms and fumonisin (FB₁ + FB₂) contamination. In all years/sites, treatments applied at the beginning of consistent ECB flight activity were most effective in controlling insect damage on ears. Fungal ear rot and fumonisin contamination were significantly affected by ECB control. The efficacy of the best timing of insecticide application in controlling fumonisin contamination was, on average, 93% compared to the untreated control. Contamination levels of these mycotoxins increased with either an earlier or later treatment. Furthermore, an earlier insecticide application showed lower fumonisin contamination than a treatment applied after the adult flight peak. Production of maize kernels and maize-based foods that do not exceed the maximum international and EU permitted levels for fumonisins could be enhanced by appropriate insecticide treatment against second generation ECB. The optimum time for insecticide application is between the beginning of consistent adult flight activity and the flight peak.     

On fumonisin incidence in monoculture maize under no‐till,conventional tillage and two nitrogen fertilisation levels

BACKGROUND: Fusarium ear rot and fumonisin contamination are serious problems for maize growers. The lack of maize genotypes highly resistant to fumonisin contamination emphasises the need for management strategies to prevent contamination by this mycotoxin. There are conflicting reports regarding no‐till and nitrogen (N) fertilisation practices in relation to the incidence of fumonisins. In this study the effect of no‐till compared with conventional tillage and of N fertilisation rates on fumonisin occurrence was investigated over three years in Northern Italy. RESULTS: The average contamination of grain by fumonisins B₁ and B₂ over the three years was significantly different, with a lower value in 2000 (516 µg kg^?1) than in the other years (5846 and 3269 µg kg^?1 in 2001 and 2002 respectively). Conventional tillage and no‐till treatments had no significant effect on the incidence of fumonisins. This finding suggests that above‐ground residues infected by Fusarium would not lead to an increase in fumonisin incidence. However, N fertilisation significantly increased fumonisin levels, by 99 and 70% in 2000 and 2001 respectively. CONCLUSION: Maize monoculture does not show a cumulative effect on the occurrence of fumonisins, while high rates of N fertiliser consistently result in elevated fumonisin levels. Both these effects can be influenced by annual meteorological fluctuations. Copyright © 2008 Society of Chemical Industry     

Accumulation of Fumonisins in Maize Hybrids Inoculated under Field Conditions with Fusarium moniliforme Sheldon

The accumulation of fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) after inoculation of 14 maize hybrids with Fusarium moniliforme has been examined in Poland during the seasons 1992–1995. Fumonisins have been detected in all 14 hybrids in amounts ranging from 0·09 mg kg^-1 FB₁+0·02 mg kg^-1 FB₂ to 93·2 mg kg^-1 FB₁+15·8 mg kg^-1 FB₂. Inoculated ears contained from <1% up to 60% of Fusarium damaged (=mouldy) kernels (FDK). Fumonisins' levels in FDK ranged from 5·1 mg kg^-1 FB₁+1·4 mg kg^-1 FB₂ up to 196·0 mg kg^-1 FB₁+62·0 mg kg^-1 FB₂. Significant influence of the year of inoculation on ear infection and fumonisins accumulation was observed. Only one hybrid (Mona) exhibited low disease score, low percentage of FDK (1·1–2·6%) and low levels of fumonisins (FB₁ from 0·09 to 1·66 mg kg^-1 and FB₂ from 0·02 to 0·42 mg kg^-1) during 3 years of experiments. © 1997 SCI.     

Timing clorpirifos + cypermethrin and indoxacarb applications to control European corn borer damage and fumonisin contamination in maize kernels

BACKGROUND: European corn borer (ECB) is the main maize pest in central and southern Europe and it promotes the infection of maize with Fusarium verticillioides, which is able to produce fumonisins. Field experiments were performed from 2006 to 2007 in northwestern Italy to determine the effects of the timing of insecticide applications on maize fungal ear rot and fumonisin contamination in natural infection conditions. Four application timings and two insecticides (clorpirifos + cypermethrin and indoxacarb) were compared each year. RESULTS: In both years, the treatments applied at the beginning of a consistent ECB flight activity and at the flight peak showed the best efficacy to control the insect damage on ears. Fungal ear rot and fumonisin contamination were clearly affected by ECB control. The efficacy of the best application timing to control fumonisin occurrence was 73% in 2006 and 84% in 2007. Earlier insecticide applications showed lower fumonisin contamination than treatments applied after the adult flight peak. CONCLUSION: The production of maize and maize‐based foods with a low fumonisin content may be enhanced through correct insecticide application against the second ECB generation. The optimum timing of insecticides is between the beginning of a consistent adult flight activity and the flight peak. Copyright © 2009 Society of Chemical Industry     

Mycotoxin contamination of maize hybrids after infection with Fusarium proliferatum

The ear rot severity of nine maize hybrids and the accumulation of fumonisin B₁(FB₁), fumonisin B₂(FB₂), beauvericin (BEA) and fusaproliferin (FP) after artificial inoculation in the field with a toxigenic strain of Fusarium proliferatum have been investigated. Different degrees of ear rot were observed in different hybrids. Inoculated ears contained 11–38% of Fusarium-damaged kernels (FDK). Mycotoxin analyses showed a pronounced contamination of FDK with concentrations ranging from 116 to 343 mg kg⁻¹ for FB₁, from 8 to 29 mg kg⁻¹ for FB₂, from 1 to 14 mg kg⁻¹ for BEA and from 2 to 10 mg kg⁻¹ for FP. Lower levels of contamination were found in healthy-looking kernels (up to 26, 2, 0.2 and 0.3 mg kg⁻¹ for FB₁, FB₂, BEA and FP respectively). A good correlation was observed between mycotoxin contamination and the Fusarium ear rot index, calculated on the basis of average ear infection with a scale ranging from 0 to 500 to represent healthy cobs and totally rotted cobs respectively. © 1999 Society of Chemical Industry     

Fumonisin detection and analysis of potential fumonisin‐producing Fusarium spp. in asparagus (Asparagus officinalis L.) in Zhejiang Province of China

BACKGROUND: Fumonisins are mycotoxins produced by a number of Fusarium species, including several pathogens of asparagus plants. China is one of the largest asparagus producers in the world. In this study, we analysed the contamination of fumonisins and fumonisin‐producing fungi in asparagus spear samples from Zhejiang Province, the major asparagus production province in China. RESULTS: The asparagus did not contain a detectable level of fumonisins. However, the recovery of Fusarium in asparagus was 72.7%, including F. proliferatum (40.9%), F. oxysporum (22.7%), F. acuminatum (4.55%) and F. equesti (4.55%). A multiplex PCR targeting the internal transcribed spacer sequence (ITS), translation elongation factor 1‐α (TEF), and key biosynthetic genes FUM1 and FUM8, was used to simultaneously determine the identity and the biosynthetic ability of the fungal isolates. Fungal isolates containing the FUM genes also produced fumonisins in cultures, ranging from 28 to 4204 µg g^?1. F. proliferatum was the only fumonisin‐producing Fusarium species in asparagus. CONCLUSION: Although no fumonisin contamination was detected in asparagus in the current survey, we found that the majority of samples contained Fusarium spp. Because F. proliferatum is a high fumonisin‐producing species, potential health risks for human consumption of asparagus exist, if the appropriate environmental conditions are present for this fungus. Copyright © 2010 Society of Chemical Industry     

The influence of local factors on the prediction of fumonisin contamination in maize

BACKGROUND: Contamination by mycotoxins is a major concern to the maize industry in north‐east Italy where maize grain is often spoiled by Fusarium spp. In this work, fumonisins, deoxynivalenol and zearalenone were determined and an artificial neural network (ANN) model suitable for predicting mycotoxin contamination of maize at harvest time was developed. RESULTS: The occurrence of deoxynivalenol and zearalenone was very limited, while fumonisins concentration ranged from 163 and to 3663 µg kg^?1 in 2007, and from 333 to 11473 µg kg^?1 in 2008. Statistical data analysis of factors affecting fumonisins concentration revealed that irrigation, chemical treatment against the European corn borer and harvest date significantly affected the level of contamination (P < 0.05), although the relevance of the factors was different in 2007 and 2008. The neural network approach showed a significant correlation between ascertained values and predictions based on agronomic data. CONCLUSION: This is the first time that an artificial neural network has been used to predict fumonisin accumulation in maize: the prediction has been shown to have the potential for the development of a new approach for the rapid cataloging of grain lots. Copyright © 2012 Society of Chemical Industry     

Analysis of potential fumonisin‐producing Fusarium species in corn products from three main maize‐producing areas in eastern China

BACKGROUND: Fusarium species are common fungal contaminants of maize and a number of them can produce mycotoxin fumonisins. China is one of the largest maize producers in the world. This study investigated the contamination of maize samples from three areas in eastern China by Fusarium and fumonisin‐producing fungi as well as their fumonisin‐producing potential. RESULTS: A total of 22 Fusarium strains were isolated, 19 of which were able to produce fumonisin. Among the 19 strains, 16 belonged to F. verticillioides, two to F. subglutinans and one to F. proliferatum. The majority (17/19) of the fumonisin‐forming strains were high FB₁ producers, which is a potential health risk for the population in these areas. Fusarium contamination in samples from the mideastern area was the most serious (11 Fusarium strains, with nine producing fumonisin, isolated from 24 samples), followed by the northeastern area (nine Fusarium strains, with all nine producing fumonisin, isolated from 21 samples) and the southeastern area (two Fusarium strains, with one producing fumonisin, isolated from 19 samples). CONCLUSION: Although the overall levels of FBs and contamination by fumonisin‐producing fungi in corn samples were not serious, the contaminating Fusarium strains possessed fairly strong toxicogenic ability and potential risk for food safety. © 2012 Society of Chemical Industry     

Relative severity of fumonisin contamination of cereal crops in West Africa

Traditional and improved varieties of maize, pearl millet and sorghum were planted by small-scale farmers under the direction of the International Institute for Tropical Agriculture in two Nigerian agro-ecological zones: the Sudan Savanna and the Northern Guinea Savanna. Samples were collected for the determination of Fusarium infection and fumonisin (B₁, B₂ and B₃) contamination. A previous paper reported Aspergillus infection and aflatoxin contamination of these samples. Fusarium infection levels, measured by per cent kernels infected, were modest with mean levels for the above cereals of 16% ± 11% (SD), 12% ± 7% and 13% ± 16%, respectively. However, the Fusarium species recovered from maize were predominantly the fumonisin producers F. verticillioides and F. proliferatum, together making an infection rate of 15% ± 10%, whereas these species were present to a limited extent only in the other two cereals, 1% ± 1% for pearl millet and 2% ± 6% for sorghum. Fumonisin contamination was variable but reflected the diversity of Fusarium producers in these three cereals. Mean levels were 228 ± 579 µg kg^–1 (range < 5–2860 µg kg^–1) for maize, 18 ± 7 µg kg^–1 (range = 6–29 µg kg^–1) for pearl millet and 131 ± 270 µg kg^–1 (range < 5–1340 µg kg^–1) for sorghum. Together with previous results on aflatoxin, this study confirmed the co-occurrence of aflatoxins and fumonisins in maize as well as in the traditional African cereals, millet and sorghum (89% co-occurrence across all three cereals). The low fumonisin levels may be ascribed to the use of good agricultural practices. Of the Fusarium species present, those in maize consisted mainly of fumonisin producers, the opposite of what was observed in pearl millet and sorghum. It is concluded that replacement of maize by pearl millet and sorghum could improve food safety with regards to aflatoxin B and fumonisin B exposure.     

Associations of planting date,drought stress,and insects with Fusarium ear rot and fumonisin B1 contamination in California maize

Fusarium ear rot, caused by Fusarium verticillioides, is one of the most common diseases of maize, causing yield and quality reductions and contamination of grain by fumonisins and other mycotoxins. Drought stress and various insects have been implicated as factors affecting disease severity. Field studies were conducted to evaluate the interactions and relative influences of drought stress, insect infestation, and planting date upon Fusarium ear rot severity and fumonisin B₁ contamination. Three hybrids varying in partial resistance to Fusarium ear rot were sown on three planting dates and subjected to four irrigation regimes to induce differing levels of drought stress. A foliar-spray insecticide treatment was imposed to induce differing levels of insect injury. Populations of thrips (Frankliniella spp.), damage by corn earworm (Helicoverpa zeae), Fusarium ear rot symptoms, and fumonisin B₁ levels were assessed. There were significant effects of hybrid, planting date, insecticide treatment, and drought stress on Fusarium ear rot symptoms and fumonisin B₁ contamination, and these factors also had significant interacting effects. The most influential factors were hybrid and insecticide treatment, but their effects were influenced by planting date and drought stress. The more resistant hybrids and the insecticide-treated plots consistently had lower Fusarium ear rot severity and fumonisin B₁ contamination. Later planting dates typically had higher thrips populations, more Fusarium ear rot, and higher levels of fumonisin B₁. Insect activity was significantly correlated with disease severity and fumonisin contamination, and the correlations were strongest for thrips. The results of this study confirm the influence of thrips on Fusarium ear rot severity in California, USA, and also establish a strong association between thrips and fumonisin B₁ levels.     

Occurrence of the C-series fumonisins in maize from the former Transkei region of South Africa

Fumonisins are a group of structurally related mycotoxins produced mainly in maize by Fusarium verticillioides and F. proliferatum. The most abundant naturally occurring analogue is fumonisin B₁ (FB₁), with lesser amounts of fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃) occurring. The C-series fumonisins (FCs) are structurally analogous to the B-series but lack the C-1 methyl group. Good and mouldy subsistence-grown maize samples were collected from the Centane and Bizana districts in the former Transkei region of South Africa. After extraction with methanol/water and clean-up on strong anion exchange solid phase extraction cartridges, FB₁, FB₂, FB₃, FC₁, FC₃ and FC₄ were determined by reversed-phase LC–MS/MS using positive ion electrospray ionisation. FB₁ levels in both good and mouldy maize from Centane (means (±SD) 2.75?±?2.24 and 23.4?±?12.5?mg?kg^?1, respectively) were higher than the corresponding levels in maize samples from Bizana (means 0.056?±?0.157 and 3.71?±?5.01?mg?kg^?1, respectively). Similarly, FC₁ levels in both good and mouldy maize from Centane (means 0.107?±?0.099 and 0.814?±?0.391?mg?kg^?1, respectively) were higher than in Bizana, where FC₁ was detected in only one (0.018?mg?kg^?1) of 19 good maize samples and occurred in mouldy maize with a mean of 0.102?±?0.135?mg?kg^?1. A significant correlation (r?=?0.982, p?<?0.01) was observed between FB₁ and FC₁ levels in all samples, with FC₁ levels at 3.3% of the corresponding FB₁ levels. FC₄ levels were similar to FC₁, whereas only low amounts of FC₃ were detected.     

Local post-harvest practices associated with aflatoxin and fumonisin contamination of maize in three agro ecological zones of Tanzania

A survey was undertaken of a total of 120 farmers, 40 from each of the three studied agro-ecological zones of Tanzania, to determine local post-harvest management practices associated with aflatoxin (AF) and fumonisin (FB) contamination of maize. Data on practices (collected using a structured questionnaire) and maize samples were obtained from each of the 120 farmers. FB and AF contamination in the samples were analysed by HPLC. A total of 45% and 85% of maize samples were positive for AF and FB respectively, with levels ranging from 0.1 to 269 μg kg^?1 for AF and from 49 to 18 273 μg kg^?1 for FBs. Significant differences in contamination level were observed among the three agro-ecological zones. Farmers in the three agro-ecological zones practised similar practices in varying degrees. Drying, sorting and protecting maize against insect infestation are practices that showed significant association with AF or FB contamination of maize. Drying maize on mat/raised platform, sorting (damaged, discoloured and moulded grains) and application of synthetic insecticides during storage are practices that were associated with less contamination of maize with AF and FB. The results can be used to advise on effective post-harvest strategies for prevention of AF and FB contamination of maize in rural Tanzania.     

Fumonisins exposure from freshly harvested and stored maize and its relationship with traditional agronomic practices in Rombo district,Tanzania

The exposure to fumonisins from the maize harvest of 2006 (before and after sorting and storage) for 67 families was assessed along with its statistical association with agronomic practices in Rombo, Tanzania. Fumonisins were determined by high-performance liquid chromatography (HPLC) and exposure estimated based on 60 kg body weight and maize intake of 356 g per person day^?1. Based on contamination in the unsorted maize, exposure for 27% of the families would exceed the provisional maximum tolerable daily intake of 2 µg kg^?1 body weight. The odds ratio of fumonisin exposure from maize hybrid 614 (H614) were: two times higher compared with non-H614 maize (p = 0.089); and five times higher when the maize was grown without fertilizer (p = 0.004). Sorting maize before storage reduced the percentage of families with unacceptable exposures to 6%. Therefore, the results imply that planting of the non-H614 seeds using fertilizers combined with pre-storage sorting of maize significantly minimizes fumonisins exposure in Rombo. A field experiment to verify these findings is needed.     

Sensitive enzyme‐linked immunosorbent assay and rapid one‐step immunochromatographic strip for fumonisin B1 in grain‐based food and feed samples

BACKGROUND: Maize contaminated with mycotoxin fumonisin B1 poses a global threat to agricultural production. In this study, polyclonal antibodies (pAb) specific to fumonisin B1 were generated from rabbits immunised with fumonisin B1–keyhole limpet haemocyanin (KLH). These antibodies were used to establish a sensitive competitive direct enzyme‐linked immunosorbent assay (cdELISA) and gold nanoparticle immunochromatographic strip for detecting fumonisin B1 levels in maize‐based foods and feeds. RESULTS: In cdELISA, fumonisins B1, B2 and B3 at concentrations of 0.42, 0.58 and 81.5 ng mL^?1 respectively caused 50% inhibition (IC₅₀) of binding of fumonisin B1–horseradish peroxidase (HRP) to the antibodies. Effective on‐site detection of fumonisin B1 was achieved by developing a rapid and sensitive pAb‐based gold nanoparticle immunochromatographic strip. This strip had a detection limit of 5 ng mL^?1 for fumonisin B1 in maize‐based samples. Additionally, the whole analytical process could be completed within 10 min. Close examination of 15 maize‐based samples by cdELISA revealed that 11 were fumonisin‐positive, with a mean concentration of 435 ± 20.1 ng g^?1. These results correlated well with those obtained by immunochromatographic strip. CONCLUSION: Both cdELISA and immunochromatographic strip methods established in this study are sensitive for rapid detection of fumonisins in agricultural commodities. Copyright © 2010 Society of Chemical Industry     

Fusarium infection of maize and maize-based products and exposure of a rural population to fumonisin B1 in Limpopo Province,South Africa

Fusarium species (spp.) and fumonisin B₁ (FB₁) contaminations were monitored in maize and porridge consumed by a rural population of Limpopo Province, South Africa. Faecal samples were also analysed for FB₁ as a means of estimating the degree of dietary exposure to this mycotoxin. In total, 142 samples of maize (n?=?54), porridge (47) and faeces (41) were screened for Fusarium spp. using a serial dilution technique followed by DNA sequencing, while FB₁ was further screened and quantified by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), respectively. At least four species of Fusarium were identified, of which F. verticillioides was the most prevalent in all three sample types analysed. The contamination levels of FB₁ were significantly higher in 87% of maize sampled (range?=?101–53,863?µg?kg^?1) as compared with porridge (74% incidence rate; range?=?0.2–20?µg?kg^?1) and faecal samples (100% incidence rate; range?=?0.3–464?µg?kg^?1). Thus, it can be deduced that the level of human exposure to FB₁ via the consumption of maize was high as several samples contained levels exceeding 1000?µg?kg^?1, which was strongly supported by the levels found in faecal samples. Further data revealed that a high proportion of FB₁ is destroyed or removed by processing maize into porridge. As maize porridge is consumed as a staple, the low levels found provide a means to limit exposure to FB₁. Levels of FB₁ found in the faeces which were higher indicate that other foods contaminated with the toxin are also consumed.     

Survey of fumonisins B1, B2 and B3 in conventional and organic retail corn products in Spain and Italy and estimated dietary exposure

A survey was conducted to determine the occurrence of fumonisin B₁, B₂ and B₃ during 2007 in 186 samples of organic and conventional locally available corn products. Samples included baby food (n = 62), corn flour (11), cornflakes (23), pasta (14), cookies (17) and other corn products (59) were obtained from popular markets of Valencia (Spain) and Perugia (Italy). The analytical method used pressurized liquid extraction and liquid chromatography/electrospray ionization tandem mass spectrometry with a triple quadrupole (QqQ) analyser. Of the 104 Spanish samples, 22% contained levels in the range of 2–449 µg kg^?1, 2–229 µg kg^?1 and 6–105 µg kg^?1 for FB₁, FB₂ and FB₃, respectively, while 19 (23%) of the 82 Italian samples were positive with quantifiable levels between 2–235 µg kg^?1, 3–187 µg kg^?1, and 4–40 µg kg^?1 for fumonisins B₁, B₂ and B₃, respectively. Overall, none of the Italian samples and only one organic baby food sample from a Spanish market was above the maximum permitted levels established by European legislation. Fumonisins were found mostly in corn flour followed by cookies and cornflakes. Eleven samples from Spain and nine samples from Italy were organic products, being contaminated the 72% and 77% of the samples, respectively. Analysis of the results showed that levels of fumonisins in corn products were similar in Italy and Spain. The safety of fumonisin intake through corn products was demonstrated by the calculation of the estimated daily intake of both populations considering organic and conventional products separately, which ranged from 1.7 × 10^?3 to 0.72 µg kg^?1 bw day^?1 and comparing them with the provisional maximum total daily intake (PMTDI) of 2 µg kg^?1 bw day^?1 established by the European Union.     

Risk assessment of exposure to mycotoxins (aflatoxins and fumonisins) through corn tortilla intake in Veracruz City (Mexico)

This study aimed to assess aflatoxin and fumonisin intake through corn tortilla consumption in Veracruz city. Between October 2013 and February 2015, a total of 120 corn tortilla samples (2 kg samples, 40 samples per year) were randomly collected. Aflatoxins and fumonisins were quantified by high performance liquid chromatography coupled with a fluorescence detector. A probability density function (PDF) was used for describing corn tortilla intake, body weight of the Veracruz city population, mycotoxin content of corn tortilla samples and estimated mycotoxin daily intake. The Monte Carlo method with 10,000 iterations was employed to assess the population exposure risk. The highest level of total aflatoxins (AFT) was 22.17 μg kg^?1, and 526.6 μg kg^?1 for fumonisins B₁ plus B₂, with 85% and 90% of contaminated samples respectively. Up to 69.7 % of the population was estimated to consume a higher aflatoxin dose than that recommended by the JECFA (1 ng kg^?1 of body weight per day); it was found that the recommended dose was exceeded to a greater extent in the male population, due to higher consumption of corn. The risk of fumonisin intake was less than 5 % due to the low presence and levels of these toxins in corn tortillas. The results suggest that corn tortilla consumers are at dietary risk caused by AFT contamination; this information should be considered when taking action to protect public health.