Levels Of Fumonisin Contamination Research Articles

Gradient boosting and bayesian network machine learning models predict aflatoxin and fumonisin contamination of maize in Illinois - First USA case study.

Mycotoxin contamination of corn results in significant agroeconomic losses and poses serious health issues worldwide. This paper presents the first report utilizing machine learning and historical aflatoxin and fumonisin contamination levels in-order-to develop models that can confidently predict mycotoxin contamination of corn in Illinois, a major corn producing state in the USA. Historical monthly meteorological data from a 14-year period combined with corresponding aflatoxin and fumonisin contamination data from the State of Illinois were used to engineer input features that link weather, fungal growth, and aflatoxin production in combination with gradient boosting (GBM) and bayesian network (BN) modeling. The GBM and BN models developed can predict mycotoxin contamination with overall 94% accuracy. Analyses for aflatoxin and fumonisin with GBM showed that meteorological and satellite-acquired vegetative index data during March significantly influenced grain contamination at the end of the corn growing season. Prediction of high aflatoxin contamination levels was linked to high aflatoxin risk index in March/June/July, high vegetative index in March and low vegetative index in July. Correspondingly, high levels of fumonisin contamination were linked to high precipitation levels in February/March/September and high vegetative index in March. During corn flowering time in June, higher temperatures range increased prediction of high levels of fumonisin contamination, while high aflatoxin contamination levels were linked to high aflatoxin risk index. Meteorological events prior to corn planting in the field have high influence on predicting aflatoxin and fumonisin contamination levels at the end of the year. These early-year events detected by the models can directly assist farmers and stakeholders to make informed decisions to prevent mycotoxin contamination of Illinois grown corn.

Fumonisins in African Countries.

Maize and other cereals are the commodities most contaminated with fumonisins. The maize acreage is increasing in Africa, and the maize harvest provides important foods for humans and feeds for domestic animals throughout the continent. In North Africa, high levels of fumonisins have been reported from Algeria and Morocco, while low levels have been detected in the rather few fumonisin analyses reported from Tunisia and Egypt. The West African countries Burkina Faso, Cameroon, Ghana, and Nigeria all report high levels of fumonisin contamination of maize, while the few maize samples analysed in Togo contain low levels. In Eastern Africa, high levels of fumonisin contamination have been reported from the Democratic Republic of Congo, Ethiopia, Kenya, Tanzania, and Uganda. The samples analysed from Rwanda contained low levels of fumonisins. Analysis of maize from the Southern African countries Malawi, Namibia, South Africa, Zambia, and Zimbabwe revealed high fumonisin levels, while low levels of fumonisins were detected in the few analyses of maize from Botswana and Mozambique.

Impact of graded dietary fumonisin contamination levels on the growth performance and selected health indices of turbot (Psetta maxima)

ABSTRACT A common problem that arises from the use of plant ingredients is the presence of mycotoxins. The plant meals with more potential to be used in turbot diets have a natural tendency to be contaminated by fumonisins (FUM). Psetta maxima fed: FUM 1.0, FUM 2.0 and FUM 5.0 mg kg−1 diets showed a significantly lower final mean body weight, specific growth rate and protein efficiency ratio, and a concomitantly higher feed conversion ratio, than those fed the Control or FUM 0.5 diet. At dietary concentrations of 1 to 5 mg kg−1, FUMs caused a reduction of the brush border villi length in the distal intestine and a reduction of hepatic lipid inclusion. In conclusion, dietary FUM contamination over the course of 63 days, lead to significant damaging effects on the overall growth performance, nutrient retention, organ morphology and immune status of turbot.

Assessment of aflatoxin and fumonisin contamination levels in maize and mycotoxins awareness and risk factors in Rwanda

Mycotoxins are secondary metabolites of fungi that are toxic to humans and animals when consumed in contaminated food and feed. The Rwandan climate conditions like steady temperature and sufficient rainfall favor the growth of fungi leading to high probability of mycotoxins contamination. Mycotoxins get into maize throughout the value chain from the field to processed products. Maize is promoted in Rwanda under the Crop Intensification Program (CIP), for nutrition and food security. The aim of the study was to evaluate mycotoxins (Aflatoxin and fumonisin) levels in maize and assess awareness and factors associated with mycotoxin contamination in Rwanda. Maize samples (227 kg) from season B 2019 were collected in 15 Districts in five provinces of Rwanda after an interview with a representative of the household or cooperative using a structured questionnaire. The samples were analyzed for aflatoxin and fumonisin using Reveal Q+ and AccuScan Gold Reader. From the interview, most of the respondents were not aware about aflatoxin (59.7 %) and 99 % did not know the effect of mycotoxins on human health. The average of aflatoxin contamination in surveyed districts was 6.69±13 μg/kg. In general, 90.4 % of samples scored below the limit of aflatoxin level regulated in East Africa/Kenya regulation standards (10 μg/kg). The levels of aflatoxin ranged between 0 and 100.9 μg/kg. The means aflatoxin levels within districts ranged between 1.36±0.5 μg/kg and 13.75±25 μg/kg. Among 9.6 % of the samples containing aflatoxins above the EU and Kenyan regulations standard limit, 5.7 % were above the US standards of 20 μg/kg. Within clusters, the level of aflatoxin more than 10 μg/kg was 5 %, 7 % and 18 % for stores, household and market samples, respectively. From the study, as mechanical damage of grains, moisture content of grains and the temperature of the store house increased, Aflatoxin level also increased. Fumonisin analyzed in maize ranged from 0 to 2.3 μg/g and only one sample from market showed a slightly higher level of fumonisin than the EU and US limit of 2 μg/g. More effort for aflatoxin mitigation is needed at the market level. Farmers need to be aware and taught how they can improve their agricultural system and more knowledge on mycotoxin control is needed. The results point to appropriate measures to recommend for control ofmycotoxins in Rwanda and awareness creation. Key words: AccuScan, Aflatoxin, Fumonisin, Fungal, Maize, Mycotoxins, Reveal Q+, Rwanda

The effectiveness of regulatory maximum levels for fumonisin mycotoxins in commercial and subsistence maize crops in South Africa

The fumonisins are carcinogenic mycotoxins that have been implicated in various adverse human health effects. Recently, the Codex Alimentarius Commission set maximum levels (MLs) for fumonisin mycotoxins at 4000 μg/kg for raw maize and 2000 μg/kg for maize flour and maize meal and these have been incorporated into South African health regulations. The MLs are intended to be health protective such that fumonisin exposures will be below the provisional maximum tolerable daily intake (PMTDI) of fumonisin of 2 μg/kg body weight/day set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). South Africa has an extensive commercial maize farming industry as well as a large subsistence farming population reliant on home-grown maize. The available data on fumonisin contamination levels indicates that these MLs are readily met by the commercial crop. However, the situation in subsistence farming areas such as in the Eastern Cape Province region is of concern. The daily consumption of large amounts of highly fumonisin-contaminated home-grown maize is of relevance mainly due to rudimentary milling, which is not subject to the reduction in mycotoxin contamination associated with commercial milling. Analysis of historical fumonisin data from the Eastern Cape region indicates that approximately 12.8% of raw maize and 25% of the rural locally produced flour would not meet the respective MLs of 4000 μg/kg ML and 2000 μg/kg. Further analysis shows that given the high maize intake levels of this population, only prohibitively low MLs for raw maize of around 100–300 μg/kg would be health protective for different age groups in this area. Based on this analysis, the lowering of fumonisin exposure in subsistence farmers requires an integrated approach and cannot be achieved purely by regulatory means.

Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides.

Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.

Natural incidence of Fusarium species and fumonisins B1 and B2 associated with maize kernels from nine provinces in China in 2012

Fusarium species, which can produce mycotoxins, are the predominant pathogens causing maize ear rot, a disease that results in severe economic losses and serves as a potential health risk for humans and animals. A survey was conducted in 2012 to investigate the contamination of maize by Fusarium species and fumonisins B1 and B2. A total of 250 maize samples were randomly collected from nine provinces (Hebei, Shanxi, Inner Mongolia, Yunnan, Sichuan, Guizhou, Heilongjiang, Liaoning and Ningxia) in China. Fusarium species were isolated and identified using morphological (electron microscope) and molecular methods (polymerase chain reaction (PCR) and sequencing). Fumonisins B1 and B2 were analysed using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) with OPA (2-Mercaptoethanol, o-phthaldialdehyde) post-column derivatisation. A total of 2321 Fusarium isolates (20.7%) were obtained from all the samples. These isolates included nine Fusarium species, namely, F. graminearum, F. verticillioides, F. subglutinans, F. proliferatum, F. temperatum, F. oxysporum, F. equiseti, F. meridionale and F. chlamydosporum. The incidence of occurrence of Fusarium species in Guizhou was the highest, while in Inner Mongolia it was the lowest. F. verticillioides was the dominant species of maize ear rot in Liaoning, Sichuan, Hebei and Ningxia. F. graminearum was the dominant species in Yunnan, Guizhou and Shanxi. F. subglutinans was the dominant species in Heilongjiang. F. verticillioides and F. graminearum percentages were the same in Inner Mongolia. The incidence of fumonisins in Liaoning was high (up to 81.0%) and in Heilongjiang low (up to 10.3%). Except Shanxi, more than 50% of maize samples from other provinces were contaminated with fumonisins, with concentrations less than 500 ng g−1. About 33% of maize samples from Yunnan were contaminated with high levels of fumonisins, and average of fumonisin levels were 5191 ng g−1. Fusarium species causing maize ear rot in different areas in China were highly diverse and such areas with exposure to high levels of fumonisin contamination have a potential health risk for human and animals.

Analysis of fumonisin contamination and the presence of Fusarium in wheat with kernel black point disease in the United States

The ability of the fungus Fusarium proliferatum to cause kernel black point disease in wheat was previously established, but natural contamination of black point wheat with both F. proliferatum and fumonisin mycotoxins has not been studied in the United States. Low levels of fumonisins were detected in nine of 43 wheat samples with kernel black point disease that were obtained from across the United States. A subset of samples was contaminated with F. proliferatum as well as with F. fujikuroi, F. nygamai, F. thapsinum and F. verticillioides, species closely related to F. proliferatum and morphologically similar to it in that they produce chains of asexual spores, or conidia. Nevertheless, of conidial chain-forming fusaria isolated from symptomatic wheat, F. proliferatum dominated. In greenhouse tests, isolates of F. proliferatum and the other species recovered from wheat samples were able to cause symptoms of kernel black point and, in some cases, low levels of fumonisin contamination of wheat. These data add to the understanding of the risk of fumonisin contamination of wheat and the potential for Fusarium species to cause kernel black point disease and fumonisin contamination of wheat. Further, the results of this study indicate that while US-grown wheat can sporadically be contaminated by fumonisins, the natural contamination levels seem to be low. The observations made provide evidence that fumonisins are not likely to be a factor contributing to the ability of Fusarium to cause kernel black point disease.

Effect of Planting Density, Irrigation Regimes, and Maize Hybrids with Varying Ear Size on Yield, and Aflatoxin and Fumonisin Contamination Levels

Corn (maize, Zea mays L.) hybrids expressing the flexibility trait in ear size (number of kernels per ear) are marketed for ability to give higher yields under adverse conditions. Altered kernel number is associated with altered number of silk, a major route for infection of kernels by aflatoxin-producing fungi such as Aspergillus flavus. The effect of plant density and irrigation level on yield and accumulation of aflatoxins and fumonisins in harvested grain was compared in a fixed-ear hybrid (Pioneer 33K81), a semi-flexible ear hybrid (Pioneer 3223) and a flexible ear hybrid (Golden Acres 8460) over a range of seeding densities (49,400, 61,750, 74,700, 86,450, and 98,800 seeds·ha–1) in non-irrigated, moderately-irrigated (6.4 cm soil water deficit) and well-irrigated plots (3.8 cm soil water deficit), during three years with variable rainfall. Irrigation increased yields in all hybrids, but in the absence of irrigation, yields were highest with the semi-flexible ear trait hybrid. In general, the hybrid with the flexible ear trait had lower optimal seeding densities than the other hybrids for each soil water regime. In general, kernel number was least affected by seeding density in the hybrid with fixed-ear trait compared to the semi- and flexible ear hybrids. The lowest levels of aflatoxin and of fumonisin contamination in harvested grain were associated with the flexible ear trait at all rainfall and irrigation levels, but there was no evidence that reducing stress by lowering seeding density reduced mycotoxin contamination. Inoculation with A. flavus resulted in much higher levels of aflatoxin and significantly higher levels of fumonisin contamination in grain of all hybrids under most conditions of rainfall and irrigation, suggesting that factors that promote A. flavus infection can affect production of both mycotoxins.

Effects of agrochemical treatments on the occurrence of Fusarium ear rot and fumonisin contamination of maize in Southern Italy

The efficacy of agrochemical treatments, based on three different fungicides combined with an insecticide, was tested in southern Italy for two years on three maize hybrids to control Fusarium ear rot of maize and the accumulation in the maize kernels of the carcinogenic mycotoxins fumonisins. Insect damage incidence and severity, disease incidence and severity, identification of Fusarium species and levels of fumonisin contamination in kernels were determined. Field trials showed in both years that natural colonization of maize kernels by the fumonisin producing species Fusarium proliferatum and F. verticillioides (up to 81.5 and 26.5%, respectively) and total fumonisin contamination (up to 68.2 μg g −1) were highly severe. For all hybrids and in both years, the treatment with the insecticide applied alone reduced the insect damage severity consistently and the content of fumonisins in the kernel only in half of the cases, whereas fungicide treatments applied in combination with the insecticide showed a further significant reduction of fumonisin contamination in the three hybrids and in both years.

Comparison of methods and optimisation of the analysis of fumonisins B1 and B2 in masa flour, an alkaline cooked corn product

A comparison study of different extraction and clean-up procedures for the liquid chromatographic analysis of fumonisins B1 (FB1) and B2 (FB2) in corn masa flour was performed. The procedures included extraction (heat or room temperature) with acidic conditions or EDTA-containing solvents, and clean-up by immunoaffinity or C18 solid-phase extraction columns. Thereafter an analytical method was optimised using extraction with an acidic mixture of methanol–acetonitrile–citrate/phosphate buffer, clean-up through the immunoaffinity column and determination of fumonisins by liquid chromatography with automated pre-column derivatisation with o-phthaldialdehyde reagent. Recovery experiments performed on yellow, white and blue masa flours at spiking levels of 400, 800 and 1200 µg kg−1 FB1 and of 100, 200 and 300 µg kg−1 FB2 gave overall mean recoveries of 99% (±6%) for FB1 and 88% (±6%) for FB2. Good recoveries (higher than 90% for both FB1 and FB2) were also obtained with corn tortilla chips. The limits of quantification of the method (signal-to-noise ratio of 10) were 25 µg kg−1 for FB1 and 17 µg kg−1 for FB2. The method was tested on different commercial corn masa flours as well as on white and yellow corn tortilla chips, showing fumonisin contamination levels (FB1 + FB2) up to 1800 µg kg−1 (FB1 + FB2) in masa flour and 960 µg kg−1 in tortilla chips. Over 30% of masa flours originating from Mexico exceeded the European Union maximum permitted level.

Levels of total fumonisins in maize samples from Italy during 2006–2008

We analysed a total of 2258 grain samples over a 3-year period (2006–2008) from 93 storage centers in the principal maize cultivation area of Italy to establish the levels of fumonisin contamination. Fumonisin concentrations were measured using ELISA (RIDASCREEN) fumonisin test kits. Mean levels of contamination were remarkably high in each year, with the highest value in 2006 (10.9 mg/kg) and the lowest in 2008 (4.8 mg/kg). Similarly, for each year, variations were quite large: from <LOQ to 77.0 mg/kg, < LOQ to 26.3, and 0.1 to 19.0 mg/kg, respectively, in 2006, 2007 and 2008. The highest fumonisin concentration was found in samples harvested in Veneto (11.1 mg/kg) and Friuli Venezia Giulia (8.9 mg/kg), while the lowest were recorded in Emilia Romagna and Piemonte (4.6 mg/kg).

Electronic nose predicts high and low fumonisin contamination in maize cultures

The ability of an electronic nose, based on a 6 metal oxide semiconductor chemical sensors array, to diagnose fungal contamination, to detect high fumonisin content and to predict fumonisin concentration was evaluated in vitro. Maize cultures were inoculated with Fusarium verticillioides, F. proliferatum, F. oxysporum, F. semitectum, F. solani and F. subglutinans. Sterilised maize cultures were used as reference. Fungal colonies and fumonisin content of the maize samples were used as covariates for statistical analyses and for electronic nose training. Univariate and multivariate exploratory data analysis showed that the electronic nose discriminated the inoculated maize culture samples according to their fumonisin content. Partial Least Square was also implemented to build a multivariate regression model based on EN signals for quantitative fumonisin prediction. The EN could correctly recognize high and low fumonisin content of maize cultures and provide a fair quantitative estimation. The validity of EN technology to perform a rapid screening of maize cultures in order to identify levels of fumonisin contamination below the acceptability threshold was established.

Determination of fumonisins in maize by HPLC with ultraviolet detection of o-phthaldialdehyde derivatives

Fumonisins are mycotoxins that are produced by various Fusarium species and occur naturally in maize and maize-based foods. Fumonisins are carcinogenic, causing liver cancer in rats, and are associated with oesophageal cancer and neural tube defects in humans. Analytical methods for individual fumonisin analogues in maize rely on reversed-phase high-performance liquid chromatographic (HPLC) separation after suitable extraction and clean-up. As fumonisins lack a useful chromophore or fluorophore, HPLC detection is achieved by suitable derivatization and sensitive, specific fluorescence detection. A widely used and validated method involves extract clean-up on strong anion exchange solid phase extraction cartridges and pre-column derivatization with o-phthaldialdehyde (OPA). However, many laboratories requiring infrequent fumonisin analysis are only equipped with HPLC with ultraviolet (UV) detection. A HPLC system equipped with both UV and fluorescence detectors connected in series was used to determine the extent to which UV offers an alternative to fluorescence detection in the above analytical method. Comparison of the detection systems using fumonisin standards indicated that fluorescence is about 20-times more sensitive than UV. Analysis of maize samples with differing fumonisin contamination levels indicated that, at fumonisin B1 levels above 1,000µg/kg, the two detection systems were comparable and gave repeatabilities equal or less than 10% on six replicate analyses. Although a sensitive fumonisin analysis requires fluorescence detection, UV may offer an alternative in certain circumstances.

Difficulties in fumonisin determination: the issue of hidden fumonisins

In this paper, the results obtained by five independent methods for the quantification of fumonisins B(1), B(2), and B(3) in raw maize are reported. Five naturally contaminated maize samples and a reference material were analyzed in three different laboratories. Although each method was validated and common calibrants were used, a poor agreement about fumonisin contamination levels was obtained. In order to investigate the interactions among analyte and matrix leading to this lack of consistency, the occurrence of fumonisin derivatives was checked. Significant amounts of hidden fumonisins were detected for all the considered samples. Furthermore, the application of an in vitro digestion protocol to raw maize allowed for a higher recovery of native fumonisins, suggesting that the interaction occurring among analytes and matrix macromolecules is associative rather than covalent. Depending on the analytical method as well as the maize sample, only 37-68% of the total fumonisin concentrations were found to be extractable from the samples. These results are particularly impressive and significant in the case of the certified reference material, underlying the actual difficulties in ascertaining the trueness of a method for fumonisin determination, opening thus an important issue for risk assessment.

A decision tool for evaluating the agronomic risk of exposure to fumonisins of different maize crop management systems in Italy

Fumonisins constitute a group of carcinogenic metabolites produced mainly by Fusarium verticillioides, the most common fungi associated with maize grain. The limits fixed for fumonisins in maize for food and feed by the European Union (EU) could represent a serious problem for maize areas in the south of Europe where F. verticillioides encounters extremely favourable meteorological and environmental conditions for its life cycle. Prevention strategies through pre-harvest agronomic management can achieve the quality and safety standards required by EU regulations. On the basis of results from agronomic field trials conducted in the North of Italy, the first version of an agronomic decision tool has been created to help farmers, collectors and processors manage fumonisin contamination in order to respect the EU fumonisin limits and the constraints required by a given market outlet. The tool is based on the concept of agronomic exposure to fumonisin risk (AEFR), which is a qualitative evaluation of the impact that a crop management system can have on fumonisin contamination. The validation has shown the validity of the decision tool, which was able to correctly classify the crop management systems of real farms according to their agronomic exposure to fumonisin risk: increasing levels of fumonisin contamination corresponded to increasing AEFR levels.

Implication of pre-drying steps with natural fumonisin contamination levels in freshly harvested corn

Maize quality regarding fumonisin contamination of 390 freshly harvested samples used by maize processing industries in the Northern region of Parana State, Brazil (2003 crop) was evaluated and correlated to the time elapsed from harvesting to the pre-drying step. Sampling was carried out at three points of the maize production chain, immediately after harvesting (n=100), at the industry delivery posts (n=200) and before the drying process (n=90). Fumonisin B1 (FB1) was detected in all the samples from the three points of the maize production chain. FB1 levels ranged from 0.11 to 12.68 µg/g (mean 1.81±2.12 µg/g) in the field samples, 0.10 to 11.83 µg/g (mean 1.83±1.75 µg/g) in the reception samples and from 0.02 to 10.98 µg/g (mean 2.31±2.38 µg/g) in the pre-drying samples. FB2 levels ranged from 0.01 to 5.26 µg/g (mean 0.84±0.94 µg/g) in the field samples, from 0.02 to 5.25 µg/g (mean 0.74±0.69 µg/g) in the reception samples and from 0.07 to 7.89 µg/g (mean 1.25±1.29 µg/g) in the pre-drying samples. Although there was no significant difference in mean fumonisin levels among the field, reception and pre-drying samples by the Tukey multiple comparison test (P&lt;0.05), there was a positive correlation (P&lt;0.05) between fumonisin levels and the time elapsed (p=0.95) from harvesting to the pre-drying step. Therefore reduction in the harvest/drying interval would be essential to assure product quality and safety and minimise potential health hazards.

Natural occurrence of mycotoxins and mycoflora of argentinien popcorn.

Argentina is the first popcorn exporting country worldwide. In 1997-1998 harvest season, 40,000 ha were sown with a production of 125,000 tons; 120,000 tons of this production were exported to more than 40 countries. The objectives of this study were to isolate and to identify the fungi present in this cereal and to assess the occurrence of mycotoxins in freshly harvested popcorn in Buenos Aires province, Argentina, in 1999. All popcorn samples showed fungal contamination. A total of 4,211 isolates were recovered from popcorn kernel samples. The prevalent species isolated wasFusarium verticillioides followed byPenicillium funiculosum, F. graminearum andAlternaria alternata. No aflatoxins, zearalenone, deoxynivalenol or ochratoxin A were detected in the 42 popcorn simples. All samples but one were contaminated with fumonisins (FB) in a range in ug/kg of (not detected-529) for FB1; (not detected-216) for FB2 and (not detected-103) for FB3. Fumonisin contamination levels in Argentinean popcorn were lower than observed in flint corn. No significant differences in fungal and fumonisins contamination levels were observed in the different tested hybrids.

Natural occurrence of fumonisins in corn from Iran.

Corn collected in the Mazandaran and Isfahan Provinces of Iran was analyzed for fumonisin B(1) (FB(1)), fumonisin B(2) (FB(2)), and fumonisin B(3) (FB(3)). The samples from Mazandaran Province, situated on the Caspian littoral of Iran, were random samples from farmers' corn lots collected in September 1998, whereas those from Isfahan Province, situated further south in the center of Iran, were bought as corn cobs in the local retail market during October 1998. All 11 samples from Mazandaran showed high levels of fumonisin contamination with FB(1) levels between 1.270 and 3.980 microg/g, FB(2) levels between 0.190 and 1.175 microg/g, and FB(3) levels between 0.155 and 0.960 microg/g. Samples from Isfahan showed lower levels of contamination with eight of eight samples having detectable FB(1) (0.010-0.590 microg/g), two of eight samples having detectable FB(2) (0.050-0.075 microg/g), and two of eight samples having detectable FB(3) (0.050-0.075 microg/g). This is the first report of fumonisin contamination of corn from Iran, in which samples from the area of high esophageal cancer on the Caspian littoral have been shown to contain high levels of fumonisins.

Incidence and levels of fumonisin contamination in Colombian corn and corn products.

A survey was conducted to determine the levels of fumonisins B1 and B2 in corn and corn-based products available in Colombia for human and animal consumption. A total of 120 samples were analyzed by acetonitrile-water extraction, cleanup with a strong-anion-exchange column, and liquid chromatography with o-phthaldialdehyde-2-mercaptoethanol derivatization and fluorescence detection. The samples of corn and corn-based products for animal intake were taken at different feed manufacturing plants, whereas the samples used for human foods where purchased from local retail stores. The number of positive samples for fumonisin B1 was 20.0% higher in corn and corn-based products for animal intake (75.0%) than in corn and corn-based products for human consumption (55.0%). The levels of fumonisin B1 were also higher in corn and corn-based products for animal intake (mean = 694 μg/kg; range = 32-2964 μg/kg), than in corn and corn-based products for human intake (mean = 218 μg/kg; range = 24-2170 μg/ kg). The incidence and levels of fumonisin B2 were lower than those for fumonisin B1. Corn and corn-based products for animal consumption had an incidence of fumonisin B2 of 58.3%, with a mean value of 283 μg/kg, and a range of 44-987 μg/kg. The incidence of fumonisin B2 in corn-based products for human intake was 35.0%, with a mean value of 118 μg/kg and a range of 21-833 μg/kg. The highest incidence and levels of fumonisins were found in samples of hominy feed, with concentrations ranging from 86 to 2964 μg/kg fumonisin B1 and 57 to 987 μg/kg fumonisin B2.