Survey of fumonisins B1, B2and B3in conventional and organic retail corn products in Spain and Italy and estimated dietary exposure

Aflatoxins and fumonisins in conventional and organic corn: a comprehensive review

This review analyzes the occurrence and co-exposure of aflatoxins and fumonisins in conventional and organic corn, and compares the vulnerability to contamination of both. The risks of fungal contamination in corn are real, mainly by the genera Aspergillus and Fusarium, producers of aflatoxins and fumonisins, respectively. Aflatoxins, especially AFB1, are related to a high incidence of liver cancer, and the International Agency Research of Cancer (IARC) classified them in group 1A 'carcinogenic to humans'. The occurrence in conventional corn is reported in many countries, including at higher levels than those established by legislation. IARC classified fumonisins in group 2B 'possibly carcinogenic to humans' due to their link with incidence of esophageal cancer. However, comparing corn and organic and conventional by-products from different regions, different results are observed. The co-occurrence of both mycotoxins is a worldwide problem; nevertheless, there is little data on the comparison of the co-exposure of these mycotoxins in corn and derivatives between both systems. It was found that the agricultural system is not a decisive factor in the final contamination, indicating the necessity of effective strategies to reduce contamination and co-exposure at levels that do not pose health risks.

Assessment of Human Mycotoxin Exposure in Hungary by Urinary Biomarker Determination and the Uncertainties of the Exposure Calculation: A Case Study

Urinary biomarkers of mycotoxin exposure were evaluated in the case of healthy people (n = 41) and coeliac patients (n = 19) by using a multi-biomarker LC-MS/MS immunoaffinity based method capable to analyse biomarkers of nine mycotoxins, i.e., fumonisin B1 (FB1), fumonisin B2 (FB2), deoxynivalenol (DON), zearalenone (ZEN), ochratoxin A (OTA), Aflatoxin B1 (AFB1), T-2 toxin, HT-2 toxin and Nivalenol (NIV). Urinary biomarker concentrations were used to calculate the probable daily intake (PDI) of fumonisin B1, deoxynivalenol, zearalenone and ochratoxin A and compared with their tolerable daily intake (TDI). The human urinary excretion rate values reported in the literature and the 24 h excretion rate measured in piglets were used to estimate and compare the PDI values of the four mycotoxins. The highest mean biomarker concentrations were found for DON (2.30 ng/mL for healthy people and 2.68 ng/mL for coeliac patients). Mean OTA concentration was significantly higher (p < 0.001) in healthy people compared to coeliac patients. PDI calculated with piglets excretion data exceeded the TDI values by a much smaller percentage than when they were calculated from human data, especially for FB₁. The uncertainties arising from the different calculations can be well perceived on the basis of these data.

Prevalence and concentration of fumonisins in cereal-based foods: a global systematic review and meta-analysis study

Cereal-based foods are utilized as an essential food segment worldwide. Nevertheless, their contamination by mycotoxins, also fumonisins, could pose a critical health risk. The present research provides the first systematic review regarding the prevalence and concentration of fumonisins in cereal-based food with the aid of a meta-analysis. In this regard, some international databases PubMed, Web of Science, Google Scholar, and Scopus were explored during the last 30 years. Among 9729 screened articles, 73 articles (which meet the proposed inclusion criteria), including 11,132 data, were incorporated in the performed meta-analysis. The overall rank order regarding the concentration of fumonisins in cereal-based foods was corn-based foods > wheat-based foods > other cereal foods > barley-based foods > rice-based foods > oat-based foods. Based on the prevalence of fumonisins, the overall rank order was other cereal foods > corn-based foods > rice-based foods > wheat-based foods > oat-based foods > barley-based food. The present meta-analysis results can be a beneficial database for risk assessment model progress, which can help industries and organizations decrease the presence of fumonisins in cereal-based food.

Dose and Exposure Time-Dependent Renal and Hepatic Effects of Intraperitoneally Administered Fumonisin B₁ in Rats

Male Wistar rats were treated intraperitoneally (i.p.) with fumonisin B₁ (FB₁; 0, 20, 50 and 100 mg/kg dietary dose equivalent) for 5 and 10 days (n = 24⁻24 in each setting) to gain dose- and time-dependent effects on antioxidant status and oxidative stress response, clinical chemical endpoints and liver, kidney and lung histopathology and lymphocyte damage (genotoxicity). FB₁ decreased feed intake, body weight gain and absolute liver weight, irrespective of the toxin dose. Relative kidney weight increased in the 10-day setting. Linear dose response was found for plasma aspartate aminotransferase, alanine aminotransferase, total cholesterol, urea and creatinine, and exposure time-dependence for plasma creatinine level. The latter was coupled with renal histopathological findings, tubular degeneration and necrosis and the detachment of tubular epithelial cells. The pronounced antioxidant response (reduced glutathione accretion, increasing glutathione peroxidase activity) referred to renal cortical response (5⁻10 days exposure at 50⁻100 ppm FB₁). Hepatic alterations were moderate, referring to initial phase lipid peroxidation (exposure time dependent difference of conjugated diene and triene concentrations), and slight functional disturbance (↑ total cholesterol). Lymphocyte DNA damage was moderate, supporting a mild genotoxic effect of FB₁.

Appropriateness to set a group health-based guidance value for fumonisins and their modified forms

The EFSA Panel on Contaminants in the Food Chain (CONTAM) established a tolerable daily intake (TDI) for fumonisin B1 (FB 1) of 1.0 μg/kg body weight (bw) per day based on increased incidence of megalocytic hepatocytes found in a chronic study with mice. The CONTAM Panel considered the limited data available on toxicity and mode of action and structural similarities of FB 2-6 and found it appropriate to include FB 2, FB 3 and FB 4 in a group TDI with FB 1. Modified forms of FBs are phase I and phase II metabolites formed in fungi, infested plants or farm animals. Modified forms also arise from food or feed processing, and include covalent adducts with matrix constituents. Non-covalently bound forms are not considered as modified forms. Modified forms of FBs identified are hydrolysed FB 1-4 (HFB 1-4), partially hydrolysed FB 1-2 (pHFB 1-2), N-(carboxymethyl)-FB 1-3 (NCM-FB 1-3), N-(1-deoxy-d-fructos-1-yl)-FB 1 (NDF-FB 1), O-fatty acyl FB 1, N-fatty acyl FB 1 and N-palmitoyl-HFB 1. HFB 1, pHFB 1, NCM-FB 1 and NDF-FB 1 show a similar toxicological profile but are less potent than FB 1. Although in vitro data shows that N-fatty acyl FBs are more toxic in vitro than FB 1, no in vivo data were available for N-fatty acyl FBs and O-fatty acyl FBs. The CONTAM Panel concluded that it was not appropriate to include modified FBs in the group TDI for FB 1-4. The uncertainty associated with the present assessment is high, but could be reduced provided more data are made available on occurrence, toxicokinetics and toxicity of FB 2-6 and modified forms of FB 1-4.

Fusarium toxins in corn food products: a survey of the Serbian retail market

This paper presents data on the occurrence of Fusarium toxins - zearalenone (ZEA), deoxynivalenol (DON) and fumonisins (FUMs) B1 and B2 - in corn flours and corn flakes marketed in Serbia. A total of 71 samples were collected over 2013-2016 and analysed using HPLC with UV or fluorescence detection. In the case of corn flours, none of the samples taken in 2013 exhibited the presence of ZEA or DON, whereas 90% were positive for FUMs. In 2015, occurrence was very high: ZEA 93%, DON 86% and FUMs 100% (mean 43.3, 322.6 and 323.0 μg kg^-1, respectively), with 21% of the samples exceeding the maximum level for ZEA and 7% for DON and FUMs. In 2016, a lower occurrence was recorded in the case of ZEA (75%) and DON (38%), with drastically lower mean contamination levels (six- and 10-fold, respectively), while FUMs stayed at 97%, with twofold lower mean. The maximum level was exceeded only for ZEA (3%). The frequency of ZEA-DON-FB1 co-occurrence was 86% in 2015 and 25% in 2016. Regarding corn flakes, occurrence summarised for the study period was 87% ZEA, 73% FUMs and 40% DON. One sample (7%) exceeded the maximum levels for both ZEA and DON. Observed occurrence changes were in agreement with the climatic conditions during corn growing seasons preceding the market release of the processed products.

Are Treated Celiac Patients at Risk for Mycotoxins? An Italian Case-Study

Urinary biomarkers of mycotoxin exposure were evaluated in a group of celiac patients (n = 55) and in a control group of healthy subjects (n = 50) following their habitual diet. Deoxynivalenol (DON), zearalenone (ZEN), and fumonisin B1 (FB1) were monitored in 105 urinary samples collected from the two groups. Dietary habits were also recorded through compilation of a seven-day weighed dietary diary. Biomarkers of mycotoxin exposure were detected in 21 celiac patients and in 15 control subjects, corresponding to about 34% of total participants. In particular, ZEN was the most detected mycotoxin among all the studied subjects with a total of 19 positive cases. Results did not show a statistically significant difference in mycotoxin exposure between the two groups, and the presence of specific mycotoxins was not related to the intake of any particular food category. Our findings suggest little urgency of specific regulation for gluten free products, although the prevalence of exposure observed in free-living diets of both celiac and healthy subjects underlines the need of a constant surveillance on mycotoxins occurrence at large.

Fumonisins in corn (Zea mays L.) from Southern Brazil

A total of 232 samples of corn commercialised in Santa Catarina state, Southern Brazil (temperate zone climate), were evaluated from 2007 to 2012 for fumonisins (FBs: FB1 and FB2). Before performing this study, a FBs method with liquid chromatography and fluorescence detection (ex. 335; em. 440 nm) was validated first. FBs were detected in 46.6% (108 samples), with values ranging from 66 to 7832 µg kg(-1) for FB1 and 110 to 1201 µg kg(-1) for FB2. The number of contaminated corn samples for FB1 and FB2 varied and often presented contamination of FB1 only. Per year of analysis, the numbers were: n = 22/8(FB1/FB2), 44/5(FB1/FB2), 25/12(FB1/FB2), 4(FB1), 6(FB1) and 7(FB1) in 2007, 2008, 2009, 2010, 2011 and 2012, respectively. The contamination percentage was 42.3/15.4, 59.5/6.8, 43.8/21.1, 36.4, 35.3 and 33.3%, respectively, during these years. Consumers can be exposed to these mycotoxins and their health can be at risk through the consumption of contaminated corn.

Mycotoxins: occurrence, toxicology, and exposure assessment

Mycotoxins are abiotic hazards produced by certain fungi that can grow on a variety of crops. Consequently, their prevalence in plant raw materials may be relatively high. The concentration of mycotoxins in finished products is usually lower than in raw materials. In this review, occurrence and toxicology of the main mycotoxins are summarised. Furthermore, methodological approaches for exposure assessment are described. Existing exposure assessments, both through contamination and consumption data and biomarkers of exposure, for the main mycotoxins are also discussed.

Study of the chemical reduction of the fumonisins toxicity using allyl, benzyl and phenyl isothiocyanate in model solution and in food products

Fumonisins (FBs) are bioactive compounds produced by several strains of Fusarium spp. which contain a polyketide structure similar to sphinganine. These mycotoxins contain a free amino group that could work as an electron donor and react with the electrophile carbon present within the isothiocyanate (ITC) group. The objective of this study was to determine the effect of ITCs (allyl, benzyl and phenyl) on the stability of FB(1), FB(2) and FB(3). Firstly, PBS solutions at three pH levels (4, 7 and 9) were prepared and added with pairs of one FB (1 mg/L) plus one ITC (1 mg/L). Then, gaseous ITC was used to fumigate corn kernels and corn flour contaminated with FBs produced by Gibberella moniliformis CECT 2987 in situ. Mycotoxin levels were evaluated using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS), while products formed from the reaction of FBs and ITCs were examined by liquid chromatography coupled to mass spectrometry-linear ion trap (LC-MS-LIT). The reduction of FB(1) and FB(2) in solution ranged from 42 to 100% on a time-dependent manner. This variance was greatly influenced by pH. In general, lower pH levels eased the reaction between ITCs and FBs. ITC fumigation treatment (50, 100 and 500 μL/L) was able to reduce 53-96% of FB(1) levels, 29-91% of FB(2) and 29-96% of FB(3). Four reaction products between the bioactive compounds employed in this study were identified, corresponding to FB + ITC conjugates.

Mycobiota and mycotoxin contamination of maize flours and popcorn kernels for human consumption commercialized in Spain

Mycobiota and co-occurrence of aflatoxins, citrinin, ochratoxin A and zearalenone in 30 samples of maize flours and 30 of popcorn kernels purchased in Spain for human consumption were determined. The mycotoxin-producing ability of Aspergillus, Fusarium and Penicillium spp. was also studied. Total fungal counts of maize flours ranged from <10 to 8.4 × 10(4) CFU/g and predominant mycobiota belonged to Aspergillus spp. and Penicillium spp. In popcorn kernels samples the most frequent species were Aspergillus spp., Mucorales, Fusarium spp. and Penicillium spp. Aflatoxins were produced by Aspergillus flavus and Aspergillus parasiticus, citrinin by Penicillium citrinum and Penicillium verrucosum, ochratoxin A by Aspergillus niger and patulin by Aspergillus clavatus and Penicillium griseofulvum. Identification of all the mycotoxin-producing strains as well as some Aspergillus spp. difficult to identify using phenotypic characters only was also performed by molecular methods. Aflatoxins were detected in 14 maize flours and 2 popcorn kernels samples, while ochratoxin A was detected in 4 maize flours and 10 popcorn samples. Co-occurrence of aflatoxins and ochratoxin A was found in the 4 ochratoxin-positive maize flour samples. Citrinin and zearalenone were not detected. This is the first report of aflatoxins and ochratoxin A contamination in maize flours and popcorn kernels commercialized in Spain.

Determination of fumonisins B1 and B2 in maize-based baby food products by HPLC with fluorimetric detection after immunoaffinity column clean-up

A method for the determination of fumonisin B1 (FB1) and B2 (FB2) in different commercial maize-based products for infants and young children was developed and tested in a limited validation study involving 3 laboratories. The method used extraction at 55 °C with an acidic mixture of methanol-acetonitrile-phosphate/citrate buffer, clean-up through immunoaffinity column and fumonisin determination by high performance liquid chromatography with automated pre-column derivatisation with o-phthaldialdehyde. Recovery experiments were performed at five spiking levels in the ranges of 80-800 µg/kg FB1 and 20-200 µg/kg FB2. Mean recoveries ranged from 83 to 97% for FB1 and from 61 to 78% for FB2. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 5 to 12% for FB1 and from 8 to 13% for FB2, whereas relative standard deviation for between-laboratory reproducibility (RSDR) ranged from 6 to 10% for FB1 and from 9 to 16% for FB2. The limit of quantification of the method (signal to noise ratio of 6) was 2.8 µg/kg for FB1 and 2.2 µg/kg for FB2. Fumonisins were found in 6 out of 19 maize-based baby foods obtained from the Italian retail market at levels up to 53 µg/kg.