Analysis of Patulin in Apple Products Marketed in Belgium: Intra-Laboratory Validation Study and Occurrence

Apple and apple derivatives (e.g., juices, puree) are the most important foodstuffs contaminated with patulin (PAT) in the human diet. To routinely monitor these foodstuffs and ensure that the PAT levels are below the maximum permitted levels, a method using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) has been developed. Afterwards, the method was successfully validated, reaching quantification limits of 1.2 μg/L for apple juice and cider, and 2.1 μg/kg for puree. Recovery experiments were performed with samples fortified with PAT in the range of 25-75 μg/L for juice/cider and 25-75 μg/kg for puree. The results show overall average recovery rates of 85% (RSD_r = 13.1%) and 86% (RSD_r = 2.6%) with maximum extended uncertainty (U_max, k = 2) of 34 and 35% for apple juice/cider and puree, respectively. Next, the validated method was applied to 103 juices, 42 purees and 10 ciders purchased on the Belgian market in 2021. PAT was not found in the cider samples, but it was present in 54.4% of the tested apple juices (up to 191.1 μg/L) and 7.1% of the puree samples (up to 35.9 μg/kg). When comparing the results to the maximum levels set by Regulation EC n° 1881/2006 (i.e., 50 μg/L for juices and 25 μg/kg for puree for adults, and 10 μg/kg for infants and young children), exceedances were observed in five apple juices and one puree sample, for infants and young children. Using these data, a potential risk assessment for consumers can be suggested, and it is found that the quality of apple juices and purees sold in Belgium needs further regular surveillance.

Development of a reliable UHPLC-MS/MS method for simultaneous determination of zearalenone and zearalenone-14-glucoside in various feed products

A reliable ultra-high-performance liquid chromatography–tandem mass spectrometry method (UHPLC-MS/MS) was developed for the simultaneous determination of two mycotoxins, that is, zearalenone (ZEN) and zearalenone-14-glucoside (ZEN-14G) in formula feed, concentrated feed, and premixed feed products. An improved sample pretreatment was achieved with the hydrophilic–lipophilic balance (HLB) cartridges efficiently removing the impurities and enriching the target analytes in different feeds. The critical parameters affecting the performance of the solid-phase extraction (SPE) procedure were carefully optimized, and 20% acetonitrile in water as the loading solution, 50% methanol in water as the washing solvent, and 5 ml of methanol as the elution solvent yielded the optimal purification efficiencies. The established method was thoroughly validated in terms of linearity (R² ≥ 0.999), sensitivity (limit of quantification in the range of 0.50–5.00 μg kg⁻¹), recovery (89.35 ± 2.67% to 110.93 ± 1.56%), and precision (RSD, 3.00–14.20%), and it was then successfully applied to investigate a total of 60 feed samples. Among them, 50 samples were found to be contaminated with ZEN (an incidence of 83.3%) at levels ranging from 0.63 to 615.24 μg kg⁻¹, whereas 22 samples were contaminated with ZEN-14G (an incidence of 36.7%) in the range of 0.89–15.31 μg kg⁻¹. The developed method proved to be a specific and reliable tool for intensive monitoring of ZEN and ZEN-14G in complex feed matrices.

In Vivo Kinetics and Biotransformation of Aflatoxin B1 in Dairy Cows Based on the Establishment of a Reliable UHPLC-MS/MS Method

The in vivo kinetics of aflatoxin B1 (AFB1) and its carry-over as aflatoxin M1 (AFM1) in milk as well as the toxin loads in the tissue of dairy cows were assessed through a repetitive feeding trial of an AFB1-contaminated diet of 4 μg kg-1 body weight (b.w.) for 13 days. This was followed by a clearance period that ended with a single dose trial of an AFB1-contaminated diet of 40 μg kg-1 b.w. An ultra-high performance liquid chromatography tandem mass spectrometry method was developed and successfully validated by the determination of linearity (R 2 ≥ 0.990), sensitivity (lower limit of quantification, 0.1-0.2 ng ml-1), recovery (79.5-111.2%), and precision relative standard deviation (RSD) ≤14.7%) in plasma, milk, and various tissues. The repetitive ingestion of AFB1 indicated that the biotransformation of AFB1 to AFM1 occurred within 48 h, and the clearance period of AFM1 in milk was not more than 2 days. The carry-over rate of AFM1 in milk during the continuous ingestion experiment was in the range of 1.15-2.30% at a steady state. The in vivo kinetic results indicated that AFB1 reached a maximum concentration of 3.8 ± 0.9 ng ml-1 within 35.0 ± 10.2 min and was slowly eliminated from the plasma, with a half-life time (T1/2) of 931.1 ± 30.8 min. Meanwhile, AFM1 reached a plateau in plasma (0.5 ± 0.1 ng ml-1) at 4 h after the ingestion. AFB1 was found in the heart, spleen, lungs, and kidneys at concentrations of 1.6 ± 0.3, 4.1 ± 1.2, 3.3 ± 0.9 and 5.6 ± 1.4 μg kg-1, respectively. AFM1 was observed in the spleen and kidneys at concentrations of only 0.7 ± 0.2 and 0.8 ± 0.1 μg kg-1, respectively. In conclusion, the in vivo kinetics and biotransformation of AFB1 in dairy cows were determined using the developed UHPLC-MS/MS method, and the present findings could be helpful in assessing the health risks to consumers.

Organisation of Multi-Mycotoxin Proficiency Tests: Evaluation of the Performances of the Laboratories Using the Triple A Rating Approach

In accordance with the International Standard Organization ISO 17043, two proficiency tests (PTs) for the simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁, AFG₂); deoxynivalenol; fumonisins FB₁, FB_2, and B₃; ochratoxin A, the T-2 toxin; and the HT-2 toxin were conducted in 2019 and 2020 using cornflakes and rusk flours that were prepared in house. The homogeneity and the stability of these materials were verified according to the criteria laid down in ISO 13528 using randomly selected samples. Most of the targeted toxins were found to be homogenously distributed in both materials with no significant changes during the timescale of the PTs. Next, the materials were distributed to approximately 25 participating laboratories from Europe, Canada, and the United States. The obtained datasets were computed using robust statistics. The outliers were checked and removed, and the toxin concentrations were assigned as the consensus value of the results of the participants at Horwitz ratios <1.2. The z scores were generated for all mycotoxins, and the results were pooled to calculate the relative sum of squared z scores (SZ2) indexes and were clustered according to the triple A rating. Overall, at least 80% of the participating laboratories achieved good and acceptable performances. The most frequent categories assigned to good performances (SZ2 ≤ 2) were AAA (51%) and BAA (13%). Clusters of BBA + CBA (6%) included laboratories reporting acceptable z scores <90% of the total z scores for less than 90% or 50% of the mycotoxins targeted in the 2 matrices. The triple A rating seems to be appropriate in evaluating the performances of laboratories involved in multi-mycotoxin analyses. Accredited and non-accredited analytical methods achieved good and acceptable performances.

Citrinin Determination in Food and Food Supplements by LC-MS/MS: Development and Use of Reference Materials in an International Collaborative Study

The development of incurred reference materials containing citrinin (CIT) and their successful application in a method validation study (MVS) in order to harmonize CIT determination in food and food supplements are demonstrated. CIT-contaminated materials made of red yeast rice (RYR), wheat flour, and Ginkgo biloba leaves (GBL), as well as food supplements made of red yeast rice (FS-RYR) and Ginkgo biloba leaves (FS-GBL), were manufactured in-house via fungal cultivation on collected raw materials. The homogeneity and stability from randomly selected containers were verified according to the ISO 13528. CIT was found to be homogenously distributed and stable in all contaminated materials, with no significant degradation during the timescale of the MVS when storage was performed up to +4 °C. Next, an MVS was organized with eighteen international laboratories using the provided standard operating procedure and 12 test materials, including three RYRs (blank, <50 µg/kg, <2000 µg/kg), two wheat flours (blank, <50 µg/kg), two GBL powders (blank, <50 µg/kg), three FS-RYRs (blank, <50 µg/kg, <2000 µg/kg), and two FS-GBLs (blank, <50 µg/kg). The results of seven CIT-incurred materials showed acceptable within-laboratory precision (RSDr) varying from 6.4% to 14.6% and between-laboratory precision (RSDR) varying from 10.2% to 37.3%. Evidenced by HorRat values < 2.0, the results of the collaborative trial demonstrated that the applied analytical method could be standardized. Furthermore, the appropriateness of producing CIT reference materials is an important step towards food and feed quality control systems and the organization of proficiency tests.

A reliable and accurate UHPLC-MS/MS method for screening of Aspergillus, Penicillium and Alternaria mycotoxins in orange, grape and apple juices

An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for simultaneous determination of 15 mycotoxins, including aflatoxins (B1, B2, G1, and G2), ochratoxins (A, B, and C), citrinin, patulin, and emerging Alternaria toxins (alternariol, alternariol monomethyl ether, altenuene, tentoxin, tenuazonic acid, and altenusin) in orange, grape and apple juices. Different extraction approaches, sorbents, chromatographic columns and mobile phases were investigated for establishment of an optimal QuEChERS procedure and UHPLC-MS/MS conditions. Recoveries were in the range of 74-110%, and the limits of detection (LODs) and limits of quantification (LOQs) ranged from 0.05 to 0.1 ng mL-1 and from 0.1 to 5.0 ng mL-1, respectively. Matrix effects were evaluated and matrix-matched calibration curves were used to compensate for matrix effects and achieve accurate quantification. The correlation coefficients (R2) of linearity were higher than 0.99 and the relative standard deviations (RSDs) of intra- and inter-day precision were under 13%. The method was subsequently applied to 22 fruit juice samples. The high frequencies (90.9%) of mycotoxins not only proved the reliability and sensitivity of the currently established method, but also demonstrated that fruit juices are susceptible to different mycotoxins, which need to be continuously monitored in the future.

Dietary exposure assessment and risk characterization of citrinin and ochratoxin A in Belgium

Exposure to mycotoxins is a worldwide problem. To ensure public health, it is imperative to characterize the risks related to these toxins. The present study aims to conduct a dietary exposure assessment of citrinin (CIT) and ochratoxin A (OTA) in the Belgian population using consumption data of a variety of foodstuffs. A total of 367 food samples from different food categories were collected in Belgian supermarkets and analysed for CIT and OTA using a validated liquid chromatography-tandem mass spectrometry method. Daily CIT and OTA exposure to the Belgian population was calculated based on the analytical results and food consumption data in three age categories (3-9, 10-17 and 18-64 years), obtained from a national food consumption survey. Furthermore, a risk characterization was performed for CIT, in which no intake values exceeded the tolerable daily intake (TDI) of 200 ng kg^-1 bw day^-1, indicating no health risk. However, a CIT intake level of 187 ng kg^-1 bw day^-1 was detected for children in the age category of 3-9 years in the worst case scenario for rice, indicating that rice consumption could contain a potential health hazard for young children. For OTA, a potential health risk was detected in several food categories (biscuits, croissants, rice, flour, meat imitates, herbs and spices) in the higher percentiles (P99) or at maximum found concentrations when calculating the margin of exposure (MoE) for neoplastic effects. An attempt to perform a cumulative health risk assessment for both toxins was done. Although a high number of uncertainties is involved, combined margin of exposure (MoET) values indicated a potential health risk related to the combined exposure to CIT and OTA. For the first time, our study demonstrated the potential health risks of CIT and OTA after individual and combined exposure, in particular related to rice consumption. Moreover, further research is recommended concerning multiple mycotoxin exposure in young children.

A Study of Carry-Over and Histopathological Effects after Chronic Dietary Intake of Citrinin in Pigs, Broiler Chickens and Laying Hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans.

Comprehensive toxicokinetic analysis reveals major interspecies differences in absorption, distribution and elimination of citrinin in pigs and broiler chickens

A comprehensive toxicokinetic analysis of citrinin (CIT) revealed interspecies differences for all toxicokinetic parameters and in absolute oral bioavailability. Oral bioavailability for CIT was complete for broilers (113-131%), while ranging from 37 to 44% in pigs. CIT was more rapidly absorbed in pigs (T_max = 0.92 h) compared to broiler chickens (T_max = 7.33 h). The elimination of CIT was slower in pigs (T_1/2el = 26.81 h after intravenous (IV) administration) compared to chickens (T_1/2el = 1.97 h after IV administration), due to the striking difference in clearance (Cl_iv=9.87 mL/h/kg for pigs versus Cl_iv = 863.09 mL/h/kg for broilers). Also, the volume of distribution differed significantly between pigs (Vd = 0.30 L/kg after IV administration) and chickens (Vd = 2.46 L/kg after IV administration). However, plasma protein binding did not differ statistically significant (91-98%). It is imperative to further investigate biotransformation and elimination pathways in different species, including humans.

Development of a QuEChERS-Based UHPLC-MS/MS Method for Simultaneous Determination of Six Alternaria Toxins in Grapes

A simple and reliable analytical method for the simultaneous determination of alternariol (AOH), altenuene (ALT), tentoxin (TEN), altenusin (ALS), tenuazonic acid (TeA), and alternariol monomethyl ether (AME) in grapes was developed by ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure with the extraction by acetonitrile and purification by sodium chloride (0.5 g) and anhydrous magnesium sulfate (0.5 g) was established to recover the six Alternaria toxins. After validation by determining the linearity (R² > 0.99), recovery (77.8–101.6%), sensitivity (limit of detection in the range of 0.03–0.21 μg kg⁻¹, and limit of quantification in the range of 0.09–0.48 μg kg⁻¹), and precision (relative standard deviation (RSD) ≤ 12.9%), the analytical method was successfully applied to reveal the contamination state of Alternaria toxins in grapes. Among 56 grape samples, 40 (incidence of 71.4%) were contaminated with Alternaria toxins. TEN was the most frequently found mycotoxin (37.5%), with a concentration range of 0.10–1.64 μg kg⁻¹, followed by TeA (28.6%) and AOH (26.8%). ALT (10.7%), AME (3.6%), and ALS (5.4%) were also detected in some samples. To the best of our knowledge, this is the first report about the Alternaria toxins contamination in grapes in China.

Development and validation of an LC-MS/MS method for the simultaneous determination of citrinin and ochratoxin a in a variety of feed and foodstuffs

An ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI^+/--MS/MS) method for the simultaneous analysis of citrinin (CIT) and ochratoxin A (OTA) in feed (chicken and pig) and food (cereal-based products, fruit, vegetable juices, nuts, seeds, herbs, spices, vegetarian and soy products, alcoholic beverages, baby food products and food supplements) was developed. The mycotoxins were extracted from these matrices using a QuEChERS-based extraction method without any further clean-up step. The samples were 5-fold concentrated. Final extracts were analyzed using a UPLC-MS/MS system and chromatographic separation was achieved by applying a gradient elution for a total run time of 10 min. Mycotoxins were quantified using an internal calibration via analyte/¹³C-labeled internal standard ratio. The developed method was validated according to the criteria described in Commission Regulation No. 401/2006/EC and Commission Decision No. 2002/657/EC. Specificity, linearity, apparent recovery, limit of detection and quantification, intraday and interday precision, measurement uncertainty, matrix effect, and extraction efficiency were the parameters studied. Finally, 90 Belgian chicken and pig feed samples were analyzed, revealing the simultaneous presence of CIT (<LOQ - 3.90 μg/kg) and OTA (<LOQ - 5.60 μg/kg) in more than 50% of these products.

Towards the development of innovative multi-mycotoxin reference materials as promising metrological tool for emerging and regulated mycotoxin analyses

The interest in LC-MS/MS multi-mycotoxin methods unveiled an urgent need for multi-mycotoxin reference material. A multi-fusariotoxin, including deoxynivalenol (DON); zearalenone (ZEN); T-2 toxin (T-2); HT-2 toxin (HT-2); enniatin A, A1, B, and B1 (ENNs); and beauvericin (BEA), contaminated wheat flour was obtained by inoculation Fusarium spp. strains. The candidate material has successfully passed the homogeneity test and submitted to an international interlaboratory study achieved by 19 laboratories from 11 countries using their routine analytical method. The dispersion of the results for ZEN and BEA did not allow the derivation of reliable consensus values, while the assignment was only possible for DON, HT-2, T-2, and ENN A. No link was found between the methods used by the participants and the results. Significant changes in dry matter contents (≥±1.4 % of the initial dry matter) and significant changes in ergosterol contents (≥±10 %) did not occur. Using the mycotoxin contents in wheat flour stored at -80 °C as reference values, statistically significant decreases were observed only for T-2 contents at +24 °C, in contrast to the storage at -20 and +4 °C. For the other involved toxins, the candidate material was found to be stable at -20, +4, or +24 °C. Based on the T-2 decreases, a shelf life of 6 years was derived from isochronous study when the material is kept at -20 °C. At room temperature (e.g., +24 °C) or higher, this time validity drastically decreases down to 6 months. The development of this metrological tool is an important step towards food and feed quality control using multi-mycotoxin analyses. In vivo animal experiments using multi-mycotoxin-contaminated feeds dealing with the carryover or mitigation could further benefit from the methodology of this work.

Screening survey of co-production of fusaric acid, fusarin C, and fumonisins B₁, B₂ and B₃ by Fusarium strains grown in maize grains

Fusarium species isolated from Belgian maize were screened for their ability to produce fusarin C, fusaric acid, fumonisins B1 (FB1), FB2 and FB3 in maize grains. First, cultivation of Fusarium species in Myro liquid medium allowed overcoming the shortage of the standard of fusarin C on the market. All Fusarium verticillioides produced much higher contents of mycotoxins in Myro compared to Fusarium graminearum or Fusarium venenatum. The optimization of the LC-MS/MS method resulted in low limits of detection and quantification for fusarin C, fusaric acid, FB1, FB2 and FB3 determination in maize grains. Its application for screening the potential toxin production ability evidenced that the concentrations of the analytes were significantly increased at various levels when F. verticillioides strains were cultivated in maize grains and reached 441 mg kg(-1) for fusaric acid, 74 mg kg(-1) for fusarin C, 1,301 mg kg(-1) for FB1, 367 mg kg(-1) for FB2 and 753 mg kg(-1) for FB3.

In vitro glucuronidation of ochratoxin a by rat liver microsomes

Ochratoxin A (OTA), one of the most toxic mycotoxins, can contaminate a wide range of food and feedstuff. To date, the data on its conjugates via glucuronidation request clarification and consolidation. In the present study, the combined approaches of ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), UHPLC-Orbitrap-high resolution mass spectrometry (HRMS) and liquid chromatography-multiple stage mass spectrometry (LC-MS(n)) were utilized to investigate the metabolic profile of OTA in rat liver microsomes. Three conjugated products of OTA corresponding to amino-, phenol- and acyl-glucuronides were identified, and the related structures were confirmed by hydrolysis with β-glucuronidase. Moreover, OTA methyl ester, OTα and OTα-glucuronide were also found in the reaction solution. Based on these results, an in vitro metabolic pathway of OTA has been proposed for the first time.

Cross-reactivity of some commercially available deoxynivalenol (DON) and zearalenone (ZEN) immunoaffinity columns to DON- and ZEN-conjugated forms and metabolites

Seven commercially available deoxynivalenol (DON) and zearalenone (ZEN) immunoaffinity columns (IACs) were tested for cross-reactivity to conjugated forms (3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, DON-3-glucoside, DON-3-glucuronide, ZEN-glucosides, ZEN-glucuronide) and metabolites (de-epoxydeoxynivalenol, α-zearalenol, β-zearalenol) and nivalenol (NIV), using a semi-quantitative multi-mycotoxin ultra-performance liquid chromatography-tandem mass spectrometry method. The DON IACs showed cross-reactivity for nearly all DON derivatives tested. The ZEN IACs showed limited cross-reactivity to some of the ZEN derivatives. The IACs were evaluated for their potential use as sample clean-up for mycotoxins in serum.

Cross-reactivity of antibodies in some commercial deoxynivalenol test kits against some fusariotoxins

Cross-reactivity of antibodies in AGRAQUANT, DON EIA, VERATOX, ROSA LF-DONQ, and MYCONTROLDON designed for deoxynivalenol (DON) determination in food and feedstuffs was evaluated against nivalenol, 3-acetylDON, 15-acetylDON, de-epoxy metabolite 1 of DON, DON-3β-glucoside, T2-toxin, HT2-toxin, fusarenone X, diacetoxyscirpenol, verrucarol, and zearalenone. Cross-reactivity measurements were run in water using the 50% reduction of absorbance of the blank for ELISA kits or through direct DON determination upon using the standards of mycotoxins via ROSA LF-DONQ or MYCONTROLDON. For the tested toxin concentrations, all DON kits have low cross-reactivity toward diacetoxyscirpenol, T2-toxin, HT2-toxin, verrucarol, and zearalenone and moderate cross-reactivity toward 15-AcetylDON and fusarenone X. AGRAQUANT, DON EIA, and VERATOX kits showed high cross-reactivity in various ranking orders against DON-3-Glc, DOM-1, and 3AcDON. DON EIA showed also high cross-reactivity against nivalenol and fusarenone X. These mycotoxins could coexist in food or feedstuffs, and analytical results can be wrongly interpreted. Cross-reactivity does not allow checking the compliance with the legal norms, but it does allow an overall risk assessment for the consumers. Updating regularly the cross-reactivity evaluation of the produced batches is recommended for 3-acetylDON, nivalenol, DON-3-Glc, de-epoxy metabolite 1, and fusarenone X.

Mycotoxin analyses in some home produced eggs in Belgium reveal small contribution to the total daily intake

Low levels of deoxynivalenol (DON, range: 2.6-17.9 ng/g) and its metabolite de-epoxy-DON (DOM-1, range: 2.4-23.7 ng/g) were found in 20 home-produced egg samples collected in Belgium during autumn 2006 (from 10 breeders) and spring 2007 (same breeders). DON intake assessment showed that the consumption of these eggs may contribute to less than 1% of the provisional maximum tolerable daily intake of 1 microg/kg body weight established by FAO/WHO. None of the egg samples analyzed had quantifiable levels of zearalenone (ZEA), alpha-zearalenol, beta-zearalenol, ochratoxin A (OTA) and citrinin (CIT). Intake of DON, ZEA, OTA and CIT via the consumption of home produced eggs seems not to be a matter of concern. Despite this, we recommend to continue in screening other eggs allowing to increase the sample size and the subsequent conclusion for mycotoxin contamination in eggs. As home produced food is generally not submitted to any compliance control and may be consumed in large quantities by their producers and other household members, it is worthwhile to further pay attention to the quality of feed as well as the environment in which the hens live.

Assessment of the chemical contamination in home-produced eggs in Belgium: general overview of the CONTEGG study

This overview paper describes a study conducted for the Belgian Federal Public Service of Health, Food Chain Safety and Environment during 2006-2007. Home-produced eggs from Belgian private owners of hens were included in a large study aiming to determine concentration levels of various environmental contaminants. By means of the analyses of soil samples and of kitchen waste samples, obtained from the same locations, an investigation towards the possible sources of contaminants was possible. Eggs, soils, faeces and kitchen waste samples were checked for the presence of dioxins, PCBs (including dioxin-like PCBs), organochlorine pesticides, trace elements, PAHs, brominated flame retardants and mycotoxins. The study design, sampling methodology and primary conclusions of the study are given. It was found that in some cases dioxin-like compounds were present at levels that are of concern for the health of the egg consumers. Therefore, measures to limit their contamination in eggs, produced by hens of private owners, were proposed and deserve further attention.

Intake of ochratoxin A and deoxynivalenol through beer consumption in Belgium

Estimations of ochratoxin A (OTA) and 4-deoxynivalenol (DON) exposure of the Belgian population through beer consumption were made using the results of the recent Belgian food survey and the compiled data set of OTA and DON levels in conventionally and organically produced beers in 2003-05. For the consumers of organic beers, the daily intake of OTA was 0.86 (in 2003), 1.76 (in 2004) and 0.72 (in 2005) ng kg(-1) body weight (bw), considering the mean beer consumption (0.638 litres) and the average level of OTA in 2003, 2004 and 2005, respectively. Using the 97.5th percentile of beer consumption (1.972 litres), the corresponding OTA daily intakes were 2.65, 5.44 and 2.24 ng kg(-1) bw, which are close or above the tolerable daily intake (TDI) of 5 ng kg(-1) bw. For the consumers of conventional beers, the OTA intakes were low: 0.23, 0.23 and 0.11 ng kg(-1) bw day(-1) for the average beer consumption, in 2003, 2004 and 2005 against 0.72, 0.73 and 0.34 ng kg(-1) bw day(-1) when the 97.5th percentile level was considered. As for the DON intake, the estimates were quite low for both conventional and organic beer consumers when the provisional maximum TDI (PMTDI) of 1 microg kg(-1) bw was considered. Average consumption of organic beer led to daily intakes of 0.05 and 0.04 microg DON kg(-1) bw in 2003 and 2004, respectively, whilst for conventional beer, daily intakes were 0.07 and 0.05 microg DON kg(-1) bw. At the 97.5th percentile level of beer consumption, daily intakes of 0.15 and 0.13 microg kg(-1) bw were obtained for organic beers against 0.23 and 0.17 microg kg(-1) bw for conventional ones. The results showed that beer could be an important contributor to OTA exposure in Belgium, even though a declining trend seems to be apparent during the last year of monitoring. Therefore, efforts should be devoted to maintain the OTA levels as low as reasonably achievable, especially for organic beer.

Comparison of ochratoxin A and deoxynivalenol in organically and conventionally produced beers sold on the Belgian market

Beer was chosen as a cereal-derived and homogeneous product for a comparison of organic and conventional production methods in terms of mycotoxin contamination levels. Ochratoxin A (OTA, a storage mycotoxin) and deoxynivalenol (DON, a field mycotoxin) were assessed by HPLC in organically and conventionally produced beers sold in Belgium. Immunoaffinity column (OchraTest and DONPrep) purification was used prior to HPLC analysis. For in-house validation, recovery experiments, carried out with the spiked beers in the ranges of 50-200 ng OTA l-1 and 20-100 microg DON l-1, led to the overall averages of 91% (RSD = 10%, n = 9) and 93% (RSD = 5%, n = 27), respectively. Organic beers collected during 2003-2004 were more frequently OTA-contaminated (95%, n = 40) than their conventional counterparts (50%, n = 40). Conventional beers were OTA-contaminated at a mean concentration of 25 ng l-1 (range: 19-198 ng l-1), while organic beers contained a mean level of 182 ng l-1 (range: 18-1134 ng l-1). High OTA contamination above the limit of 200 ng l-1 (up to 1134 ng l-1) occasionally occurred in organically produced beers. A complementary survey performed with the same brands in 2005 did not confirm this accidental presence of excessive OTA loads (range: 3-67 ng l-1 for 10 conventional beers and 19-158 ng l-1 for 10 organic beers). Establishing a maximum of 3 microg OTA kg-1 in malt, the application of the regulation EC No. 466/2001 (entered in force before the last sampling) may be related to the observed improvement. The overall incidence of DON was 67 and 80% in conventional and organic beers, respectively. DON concentrations ranged from 2 to 22 microg DON l-1 (mean = 6 microg DON l-1) in conventional beers, while organic beers ranged from 2 to 14 microg DON l-1 (mean=4 microg DON l-1). Thus, DON in beers does not appear to be a major matter of concern. From the statistical tests, it was concluded that the variation between different batches was significant (P < 0.0001), in contrast to that observed between different brands, showing a lack of homogeneity in the raw materials. This occurs either in organically or in conventionally produced materials. Considering these results, an optimized frequency of controls according to European Regulations EC No 466/2001 and EC No 856/2005 should be recommended to reject the irregular batches.

Development and application of analytical methods for the determination of mycotoxins in organic and conventional wheat

The aim of this study was to develop a multicomponent analytical method for the determination of deoxynivalenol (DON), ochratoxin A (OTA) and zearalenone (ZEN), nivalenol (NIV), 3-acetyl-DON (3-acDON), 15-acetyl-DON (15-acDON), zearalenol (ZOL) and citrinin (CIT) in wheat. It also aimed to survey the presence and amounts of DON, OTA and ZEN in Belgian conventionally and organically produced wheat grain and in wholemeal wheat flours. After solvent extraction, an anion-exchange column (SAX) was used to fix the acidic mycotoxins (OTA, CIT), whilst the neutral mycotoxins flowing through the SAX column were further purified by filtration on a MycoSep cartridge. OTA and CIT were then analysed by high-performance liquid chromatography (HPLC) using an isocratic flow and fluorescence detection, while the neutral mycotoxins were separated by a linear gradient and detected by double-mode (ultraviolet light fluorescence) detection. The average DON, ZEN and OTA recovery rates from spiked blank wheat flour were 92, 83 and 73% (RSDR = 12, 10 and 9%), respectively. Moreover, this method offered the respective detection limits of 50, 1.5 and 0.05 microg kg-1 and good agreement with reference methods and inter-laboratory comparison exercises. Organic and conventional wheat samples harvested in 2002 and 2003 in Belgium were analysed for DON, OTA and ZEN, while wholemeal wheat flour samples were taken from Belgian retail shops and analysed for OTA and DON. Conventional wheat tended to be more frequently contaminated with DON and ZEN than organic samples, the difference being more significant for ZEN in samples harvested in 2002. The mean OTA, DON and ZEA concentrations were 0.067, 675 and 75 microg kg-1 in conventional samples against 0.063, 285 and 19 microg kg-1 in organically produced wheat in 2002, respectively. Wheat samples collected in 2003 were less affected by DON and ZEN than the 2002 harvest. Organic wholemeal wheat flours were more frequently contaminated by OTA than conventional samples (p < 0.10). The opposite pattern was shown for DON, organic samples being more frequently contaminated than conventional flours (p < 0.10).

Ochratoxin A and citrinin loads in stored wheat grains: Impact of grain dust and possible prediction using ergosterol measurement

Crop storage should be carried out under hygienic conditions to ensure safe products, but sometimes grain dust which has settled from previous storage may be left over and incorporated to the following stored grains. This paper describes the results obtained using a lab model developed in order to assess the impact of grain dust incorporation for its direct contribution as a contaminant but also as an inoculum in stored wheat. Settled grain dust (4 samples) released from Belgian grain storages were collected and analysed by HPLC for ergosterol, ochratoxin A (OTA) and citrinin (CIT) content. For OTA and for ergosterol, there was a high degree of variability in concentrations found in the dust samples (from 17.3-318 ng g(-1) and from 39-823 microg g(-1), respectively) whilst for CIT, the range was less significant (from 137-344 ng g(-1)). Incorporation of grain dust into wheat storage contributed to an increase in the concentrations of mycotoxins in the stored grain. Dust acts as a contaminant and as an inoculum. According to these two ways, patterns of mycotoxin generation vary with the nature of the mycotoxin, the mycotoxigenic potential of dust and the water activity of the wheat. OTA and CIT showed a very versatile image when considering the amounts of toxins produced under the selected experimental conditions. The development of a robust tool to forecast the mycotoxigenicity of dust was based on the determination of ergosterol content as a general marker of fungal biomass. Present results suggest that this predictive tool would only be valid for predicting the contamination level of CIT and OTA at reasonable moisture content (14-20%). The potential risk of having highly contaminated batches from stock to stock may thus occur and this paper discusses possible pathways leading to OTA and CIT contamination either under wet or dry storage conditions. We therefore, recommend taking precautionary measures not only by controlling and maintaining moisture at a reasonable level during storage of the raw materials but also by paying more attention to the cleaning of the stores before loading in the new harvests.

Patulin in domestic and imported apple-based drinks in Belgium: occurrence and exposure assessment

Apple-based beverages are regularly consumed by adults and children in Belgium. They are locally produced or imported from other countries. The apples used as starting material for these productions are frequently contaminated by mycotoxin-producing moulds and damaged during transport and handling. The current study was undertaken to investigate whether patulin (PAT) is present in the industrial or handicraft-made apple juices and ciders consumed by the Belgian population and to assess the population's exposure to this mycotoxin through apple-based drinks. Belgian (n = 29) and imported (14) apple juices as well as ciders (7) were assayed for PAT by high-performance liquid chromatography with ultraviolet light detection. PAT was detected respectively in 79, 86 and 43% of these tested samples. However, no contaminated sample exceeded the safe level of 50 microg PAT l(-1). Levels of PAT contamination were comparable in Belgian and imported juice samples. The overall mean PAT concentrations were 9.0 and 3.4 microg l(-1) for contaminated apple juices and ciders, respectively. This study also indicates that there was no statistically significant difference in the mean PAT contamination between clear (7.8 microg l(-1)) and cloudy (10.7 microg l(-1)) apple juices, as well as between handicraft-made apple juices (14.6 microg l(-1)) and industrial ones (7.0 microg l(-1)). On the basis of the mean results, a consumer exposure assessment indicates that a daily intake of 0.2 litres apple juice contributes to 45% of the provisional maximum tolerable daily intake for a child of 10 kg body weight.

Ochratoxin A in domestic and imported beers in Belgium: occurrence and exposure assessment

Determination of ochratoxin A (OTA) concentration was performed in commercial beer in Belgium using immunoaffinity column (OchraTest) clean-up and liquid chromatography. The procedure was validated and fulfilled the European Committee for Standardization's criteria. It offered a detection limit of 3 ng l(-1) and a quantification limit of 10 ng l(-1). Recovery experiments carried out with the spiked samples in the range 50-200 ng OTA l(-1) showed an overall average recovery rate of 97% (RSD = 2.8%). The validated method was applied to the analysis of 62 Belgian beers and 20 commercial beers imported from Denmark, France, Germany, Ireland, Mexico, The Netherlands and Scotland. None of these beers exceeded the previously suggested EU limit of 200 ng l(-1). However, OTA was detected in 60 Belgian beers and in all imported beers. The average levels of contamination were 33 ng l(-1) (RSD = 112%) and 32 ng l(-1) (RSD = 81%), respectively. The highest level found was 185 ng l(-1). On the basis of the established tolerable daily intake (TDI) of 5 ng kg(-1) body weight, accepted by the scientific committee on food of the EU, this study indicates that beer consumption in Belgium is not likely to contribute to more than a few per cent of the TDI based on the average consumption. This study also shows variability of the OTA contamination in beer with time. Thus, there is a potential risk of having highly contaminated batches from time to time. We therefore recommend to control further the OTA contamination in brewery products and to take precautionary measures during harvest, transport and storage of the raw materials to maintain the OTA intake at the lowest achievable level.

Occurrence of ochratoxin A in black pepper, coriander, ginger and turmeric in India

Ochratoxin A (OA) contamination of black pepper, coriander seeds, powdered ginger and turmeric powder was estimated using indirect competitive ELISA. Samples (1 g) were extracted with 0.5% potassium chloride (KCl) in 70% methanol (5 ml) and diluted subsequently to give two-fold to ten-fold step-wise dilutions in phosphate-buffered saline containing 0.05% Tween 20 and 0.2% bovine serum albumin (PBS-T BSA). For extracts from the spices analysed, ELISA estimates of OA concentrations were compared with those made by HPLC. All estimates were within 1-2 standard deviation of the ELISA values. More than 90% of OA added to spice samples was recovered from samples containing between 5 and 100 microg/kg OA. Extracts of OA-free spice samples contained substances that interfered with ELISA, presumably because of non-specific reactions. This effect was avoided by preparing all the test solutions in extracts of OA-free spice samples. In 126 samples obtained from retail shops, OA was found to exceed 10 microg/kg in 14 (in the range of 15-69 microg/kg) of 26 black pepper samples, 20 (in the range of 10-51 microg/kg) of 50 coriander samples, two (23 microg/kg and 80 microg/kg) of 25 ginger samples and nine (in the range of 11-102 microg/kg) of 25 turmeric samples. This is the first record in India of the occurrence of OA in what are some of the most widely used spices in Indian cooking.

Transfer of ochratoxin A during lactation: exposure of suckling via the milk of rabbit does fed a naturally-contaminated feed

The transfer of ochratoxin A from the blood to the milk of lactating rabbit does and subsequently the exposure of their sucklings to the mycotoxin were investigated. An effective transfer of ochratoxin A from blood to milk was shown in lactating rabbit does fed a naturally-contaminated diet (10-20 g/kg of body weight/day) throughout a lactation period of 19 days. The ochratoxin A concentrations in plasma and in milk did not significantly change throughout the lactation period with a mean milk/plasma concentration ratio of 0.015. These variables were however significantly correlated (p < 0.05), as were the ingested amounts and milk concentrations. At slaughter, the highest concentration of ochratoxin A accumulated in the body of the rabbit does were found in kidney (1.2 g/kg) followed by liver (158 ng/kg), mammary gland (105 ng/kg) and muscle (38 ng/kg). A linear relationship was found between the ochratoxin A concentrations in milk and in the plasma of the sucklings, indicating an effective transfer of the toxin to the sucklings. If the same is true in humans, the exposure of the breast-fed infant to the toxin, which has been largely reported in the literature, should be a major matter of concern for human health.