Survey of aflatoxin B1 and ochratoxin A occurrence in traditional meat products coming from Croatian households and markets

The aim of this study was to investigate the occurrence of aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) in different traditional meat products circulating on Croatian markets, produced by a large number of households situated in different Croatian regions. The study involved a total of 410 samples of traditional pork meat products in terms of hams (n = 105), dry fermented sausages (n = 208), bacon (n = 62) and cooked sausages (n = 35), collected over four years period (2011–2014). Mycotoxin concentrations were quantified and confirmed using validated immunoassay method (ELISA) and high performance liquid chromatography with fluorescence detection (HPLC-FLD), respectively. The maximal observed OTA level in the fermented sausages and hams was around 5 times (5.10 μg/kg) to 10 times (9.95 μg/kg) higher than the maximal recommended level (1 μg/kg) stipulated for pork products in some EU countries. AFB₁ levels found in any given meat product analysed within this frame were not significantly higher (p > 0.05) than the applied method limit of detection. The results showed an occasional mycotoxin contamination of traditional meat products, especially that by OTA, pointing that to avoid such contamination meat and meat products on households should be produced and processed under standardised and well-controlled conditions.     

Occurrence of four mycotoxins in cereal and oil products in Yangtze Delta region of China and their food safety risks

A total of 76 cereal and oil products collected from Yangtze Delta region of China were analyzed for occurrences of aflatoxins (AFs), aflatoxin B₁ (AFB₁), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEN). The mycotoxins were determined by the standard detection procedures using immunoaffinity column clean-up coupled with fluorometer (or HPLC-UV). ZEN was the most prevalent toxin, with the incidence of 27.6% (range = 10.0–440.0 μg kg⁻¹), and 9.2% of the evaluated samples were contaminated with a concentration higher than that of the legislation limit of China (60 μg kg⁻¹). AFs and AFB₁ were detected in 14.5% of the samples analyzed, the concentrations ranging 1.1–35.0 μg kg⁻¹ for AFs, and 1.0–32.2 μg kg⁻¹ for AFB₁; 4.0% of the samples had the concentrations of AFs and AFB₁ higher than that of the corresponding legislation limits of China (5.0, 10.0 and 20.0 μg kg⁻¹ for different products). OTA was detected in 14.5% of the cereal and oil products collected; the concentrations ranged 0.51–16.2 μg kg⁻¹. Only 2 samples showed OTA levels higher than that of the legislation limit of China (5.0 μg kg⁻¹). DON was detected in 7.9% of the samples; the concentrations ranged 100–700 μg kg⁻¹, and none of the samples showed DON concentration higher than that of the legislation limit of China (1.0 mg kg⁻¹). A total of 15.8% cereal and oil products were contaminated with at least two mycotoxins (multiple contaminations with different combinations including AFs-ZEN, AFs-OTA-ZEN, OTA-ZEN, ZEN-DON, OTA-ZEN-DON). The dietary exposure assessment results indicated that AFs (AFB₁), OTA, DON and ZEN from cereal-based products represented a series health risk to both adults and children in Yangtze Delta region of China. This is the first report of safety evaluation associated with major mycotoxins for the area.     

Aflatoxin B1 and ochratoxin A in breakfast cereals from athens market: Occurrence and risk assessment

A method for aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) determination in breakfast cereals is described using a simultaneous methanolic-aqueous extraction followed by immunoaffinity columns clean-up step and High Pressure Liquid Chromatography (HPLC) with Fluorescence Detector (FD). Recoveries were found to be 78% and 83% for AFB₁ and OTA, respectively, while the detection limit (DL) was 0.02 ng g^?1 for both mycotoxins. Both determinations were applied in fifty five samples of breakfast cereals purchased from Athens market. Results revealed the presence of AFB₁ in 56.3% of the samples examined (mean 1.42 ng AFB₁ g^?1). Seven samples (median 3.5 ng AFB₁ g^?1) were found to be contaminated at levels higher than the EU limit (2 g g^?1). OTA was detected in 60% of the samples (mean 0.18 ng g^?1). Nineteen samples were found to be contaminated by both mycotoxins. In addition in the present study the daily exposure to AFB₁ and OTA is discussed.     

Cross-linked chitosan polymers as generic adsorbents for simultaneous adsorption of multiple mycotoxins

The primary objective of this study was to synthesize three types of cross-linked chitosan polymers and further investigate their adsorption capability for multiple mycotoxins, including aflatoxin B₁ (AFB₁), ochratoxin A (OTA), zearalenone (ZEN), fumonisin B₁ (FB₁), deoxynivalenol (DON) and T-2 toxin (T2). Among these synthetic adsorbents, cross-linked chitosan-glutaraldehyde complex presented the highest adsorption capability for AFB₁ (73%), OTA (97%), ZEN (94%) and FB₁ (99%), but no obvious adsorption for DON and T2 (<30%). The effect of various incubation conditions (contact time, dosage and pH) was also studied. Subsequently, the experimental data were fitted to Langmuir, Freundlich and Hill models. The best fitting model to describe AFB₁ and FB₁ adsorption was Langmuir model (R² ≥ 0.99), with the theoretical maximum adsorption amounts of 5.67 mg/g for AFB₁ and 15.7 mg/g for FB₁. The Hill model was the best model for OTA and ZEN adsorption (R² > 0.98), with the predicted maximum adsorption amounts were 24.8 mg/g for OTA and 9.18 mg/g for ZEN. In addition, the adsorption capability of adsorbent for the simultaneous presence of multiple mycotoxins was also evaluated in buffer system and simulated gastrointestinal condition. The results indicated that the coexisted multiple mycotoxins didn't affected the adsorption capability of adsorbent, whereas the adsorption amounts of toxins were decreased by some gastrointestinal components. The findings of this research suggest that chitosan–glutaraldehyde complex has the potential to be applied as multitoxin adsorbent material for reducing the combined adverse effect of multiple mycotoxins on humans and animals.     

A survey of mycotoxins in random street-vended snacks from Lagos,Nigeria, using QuEChERS-HPLC-MS/MS

A survey in African snacks was carried out in order to evaluate the intake of 23 mycotoxins. The African snack samples were purchased from street vendors within Lagos metropolis (Nigeria) and evaluated for the presence of 23 mycotoxins using a modified QuEChERS procedure coupled with liquid chromatography-triple quadrupole linear ion trap mass spectrometer. The snacks included akara, baked coconut, coconut candy, donkwa, groundnut cake (kulikuli), lafun, milk curd (wara), fresh and dried tiger-nuts, and yam flour. Only three mycotoxins were detected in 23.8% of the studied snacks, and at concentrations ranging from 6 to 54 μg kg⁻¹. The concentrations of aflatoxin B₁ (AFB₁) and AFB₂ reached 23 μg kg⁻¹ and 3 μg kg⁻¹, respectively. Moreover a sample of baked coconut contained α-zearalenol (α-ZOL), which was up to 54 μg kg⁻¹ in coconut candy. As considers prevalence, aflatoxins and α-ZOL were not detected in lafun and groundnut-based snacks (donkwa and kulikuli), whereas each of the three mycotoxins contaminated 12.5% (1/8) of the coconut-based samples. This is the first report of α-ZOL in cassava and coconut, and their products. AFB₁ and total aflatoxins (TAFs) concentrations exceeded the maximum allowable limit recommended by National Agency for Food and Drug Administration and Control Nigeria (NAFDAC) in one sample of baked coconut (AFB₁ = 23 μg kg⁻¹ and TAFs = 26 μg kg⁻¹) and donkwa (AFB₁ = 19 μg kg⁻¹ and TAFs = 21 μg kg⁻¹).     

Annual and regional variations of aflatoxin B1 levels seen in grains and feed coming from Croatian dairy farms over a 5-year period

The aim of the study was to investigate annual and regional differences in the level of aflatoxin B₁ (AFB₁) in grains and dairy cattle feed. Maize (n = 972), wheat (n = 201), barley (n = 147), oat (n = 136), grain mixtures (n = 168), and dairy cattle feed (n = 325) were sampled from 2009 to 2013 on different farms and in different farm factories situated in four Croatian regions. The samples were analysed for AFB₁ using the validated ELISA immunoassay. AFB₁ was determined in 16.4% of all investigated samples, among which maize was proven to be the most contaminated, with 21.7% of the samples recovered during 2013 harbouring AFB₁ in concentrations over the permissible ones. Levels higher than permitted were observed in 17.9% and 12.3% of grain mixtures and dairy cattle feed, respectively, whereas concentrations of AFB₁ determined in other crops throughout the investigated period met the stipulated requirements. The results revealed the AFB₁ occurrence to be significantly (p < 0.05) dependent on the cultivation region, with the highest levels generally found in maize harvested in 2013 and consequently in grain mixtures and cattle feed that can most likely be associated with climatic conditions as the most critical factor for mould formation, and thus also AFB₁ production.     

A UPLC-MS/MS for simultaneous determination of aflatoxins, ochratoxin A, zearalenone, DON, fumonisins, T-2 toxin and HT-2 toxin, in cereals

An ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method is described for simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB₁ and FB₂), T-2 and HT-2 toxins in cereals. Mycotoxins were separated by reverse phase liquid chromatography (RP-LC) and detected by tandem mass spectrometry using an electro spray-ionization interface (ESI) in both positive- and negative- ion modes. The mean recoveries of mycotoxins from spiked cereals ranged from 83.5% to 107.3%, whereas the limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.01 to 25 ng/g and 0.02-40 ng/g, respectively. The multi-mycotoxin method developed in this work was applied for the simultaneous determination of mycotoxins in 80 cereal samples collected from Malaysian markets. A total of 60 cereal samples (75%) were contaminated with at least one of these mycotoxins at levels greater than the LOD. Only one maize sample and two rice samples were contaminated at levels exceeding the European regulatory limits for aflatoxins and OTA (4 and 5 ng/g, respectively). The rates of the occurrence of mycotoxins in the commercial cereal samples were 50, 30, 19, 30, 16, 14, 14 and 12% for the aflatoxins (the total amount of AFB₁, AFB₂, AFG₁ and AFG₂), OTA, ZEA, DON, FB₁, FB₂, T-2 and HT-2 toxins, respectively. The results demonstrated that the procedure was suitable for the simultaneous determination of these mycotoxins in cereals and could be performed for their routine analysis in mycotoxin laboratories.     

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

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

Storage stability of maize-groundnut composite flours and an assessment of aflatoxin B1 and ochratoxin A contamination in flours and porridges

Defatting of groundnut flour used for composite development can not only improve nutritional quality of its products but also the storage stability. Maize, groundnut and their composite (full fat and defatted) flours were prepared and stored at room temperature over a period of 3 months. Storage stability of these products was assessed based on changes in water activity, peroxide value (PV), free fatty acids (FFA), thiobarbituric acid (TBA), microbiological profiling and levels of mycotoxins that included aflatoxin B₁ (AFB₁) and ochratoxin A (OTA). Overall results revealed that the rate of change of PV, FFA and TBA significantly (p ≤ 0.05) increased with increasing storage time, which was highest for full fat flours than in the defatted flours. For example, PV of the FFG and DFG were respectively, 0.88 and 0.40 mEq/kg, meanwhile TBA was 4.53 and 2.71 mg malonaldehyde/kg. There was a much higher rate of increase in FFA (%) with increasing storage time in full fat and composite flours when compared to that of their defatted counterparts. Generally, microbiological data demonstrated an increase in total microbial counts during storage in these foods possibly resulting in mycotoxins, AFB₁ (range: 9.08–38.48 μg/kg) and OTA (range: 0.33–19.50 μg/kg) in all samples with groundnut and maize having the highest contamination levels. A 127.8% increase in OTA level was noted when maize flour inclusion level in the full fat composite increased from 55 to 85%, but only a 24.7% increase in OTA level was noted in defatted composites during storage. Reducing the inclusion level of groundnut flour, the main source of AFB₁ as found, resulted in a drastic reduction in AFB₁ level in full fat and defatted composite flours by 54.1 and 76.4%, respectively, during storage. The findings highlight that shelf life stability of composites can be maintained upon defatting during the fortification process. It can therefore, be inferred that monitoring quality and safety of the raw materials as well as that of the final products during storage is crucial.     

Natural co-occurrence of aflatoxins and ochratoxin A in spices

The present study aims to determine the co-occurrence of aflatoxins (AFs) and ochratoxin A (OTA) in spices marketed in Turkey. During the period from November 2010 to August 2011, 105 samples of spices were checked for targeted mycotoxins. The mycotoxins were determined by high-performance liquid chromatography coupled with fluorescence detection (HPLC-FD) after immunoaffinity column (IAC) clean-up. The method was validated for selectivity, sensitivity, accuracy and repeatability as relative standard deviation (RSD). Good recoveries (80.7–95.7%) were obtained for mycotoxins in each food matrix, with RSD values lower than 15%.Aflatoxins were detected in 79.2% of red chilli flake, 63.6% of red chilli powder, 30.4% of black pepper powder and 21.1% of cumin samples, while none of the cinnamon powder samples contained AFs at detectable levels. Four red chilli flake and three red chilli powder samples were above the EU regulatory limit of 5 μg kg⁻¹ for AFB₁. OTA was found in 75% of red chilli flake, 54.5% of red chilli powder, 17.4% of black pepper powder, with four red chilli flake and three red chilli powder samples exceeding EU limit of 30 μg kg⁻¹. No OTA was found in cinnamon powder samples, while detectable levels of OTA were found in only one cumin sample. The co-occurrence of AFB₁ and OTA was detected in 62.5% of red chilli flake, 40.9% of red chilli powder and 4.3% of black pepper powder samples. This study reports for the first time the natural co-occurrence of AFs and OTA in spices from Turkey.     

Isolation and characterization of a Bacillus subtilis strain with aflatoxin B1 biodegradation capability

Aflatoxins are type of mycotoxins mainly produced by Aspergillus flavus and a common contaminant of food and grain, posing a serious economic and health problem worldwide. In order to find efficient bacteria to remove or detoxify these mycotoxins, a bacterial strain capable of degrading aflatoxin B₁ (AFB₁) was isolated from soil samples using a culture medium containing coumarin as the sole carbon source. Based on 16S rRNA gene sequence analysis, this isolate was identified as Bacillus subtilis JSW-1; its further characterization showed that it could inhibit the growth of A. flavus with an inhibition ratio of 58.3% and could degrade AFB₁ by 67.2% after incubation at 30 °C for 72 h. The aflatoxin B₁-degrading activity of isolate JSW-1 was predominantly attributed to the cell-free supernatant and this activity was found to be heat stable but sensitive to proteinase K treatment, indicating that the extracellular proteins or enzymes are responsible for the AFB₁ degradation. In addition, no degradation products of AFB₁ could be detected by liquid chromatography-mass spectrometry (LC-MS) analysis, indicating that the parent AFB₁ might be biotransformed to compounds with chemical properties different from that of AFB₁.     

Survey of aflatoxins and ochratoxin A in retail market chilies and chili sauce samples

The aim of this study was to determine the levels of the aflatoxins (AFs) and ochratoxin A (OTA) in 312 samples of whole chili, chili powder, crushed chili and chili sauce samples from suburbs, open market and food restaurants of Punjab, Pakistan. The analysis was carried out using HPLC with fluorescence detector, after immunoaffinity column clean-up. The results have shown that 176 out of 312 (56.4%) samples were to be positive with AFs and 126 out of 312 (40.4%) sample of chilies were found to be contaminated with OTA. Total mean level of AFB₁ and total AFs in chilies were 12.50 ± 1.91, 15.16 ± 2.22 μg/kg, respectively. The total mean level of OTA in chilies was found 16.68 ± 2.58 μg/kg, ranged from LOD to 120.9 μg/kg. Sample 39.5, 26.3 and 32.7% of chilies were found containing level of AFB₁, total AFs and OTA, higher than the recommended limits for EU, respectively. The dietary levels of 3.26, 3.52, and 3.84 μg/kg were determined for AFB₁, total AFs and OTA in chilies. The incidence and levels of AFs and OTA in chilies are higher and could pose serious health hazards for consumers.     

Co-occurrence of aflatoxins and ochratoxin A in spices commercialized in Italy

A total of 130 spice samples coming from India, China, South America, USA, Northern Africa, Europe and Sub-Saharan Africa were collected in different stores of Northern Italy. They were analysed for aflatoxins (AFs: AFB₁, AFB₂, AFG₁, AFG₂) and ochratoxin A (OTA) content by liquid chromatography with mass spectroscopy and positive electrospray ionization (LC/ESI-MS/MS), and HPLC with fluorescence detector (FLD), respectively. The analysis showed that 20 (15.4%) and 31 (23.8%) out of 130 samples were contaminated with AFs and OTA, respectively. A low level of total AFs contamination was found in the positive samples, the average concentration was 0.64 ng g⁻¹, far below the maximum threshold admitted by the European legislation (5 ng g⁻¹ for AFB₁, and 10 ng g⁻¹ for total aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂). A higher incidence of OTA was found in chili (60.0%) more than in pepper (13.3%), ranging from 2.16 to 16.35 ng g⁻¹, and from 1.61 to 15.85 ng g⁻¹, respectively. Moreover, three spice samples (2.3%) contaminated by OTA trespassed the threshold admitted by the European Regulation (EC, 2010). The co-occurrence of OTA and AFs in spices was detected in 6 out of 130 samples (4.6%), ranging from 1.61 to 15.85 ng g⁻¹ and from 0.57 to 3.19 ng g⁻¹, respectively.     

Determination of multi-mycotoxin occurrence in maize based porridges from selected regions of Tanzania by liquid chromatography tandem mass spectrometry (LC-MS/MS), a longitudinal study

Residents of certain areas of Tanzania are exposed to mycotoxins through the consumption of contaminated maize based foods. In this study, 101 maize based porridge samples were collected from villages of Nyabula, Kikelelwa and Kigwa located in different agro-ecological zones of Tanzania. The samples were collected at three time points (time point 1, during maize harvest; time point 2, 6 months after harvest; time point 3, 12 months after harvest) over a 1-year period. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was used to detect and quantify 9 mycotoxins: aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁), aflatoxin G₂ (AFG₂), fumonisin B₁ (FB₁), fumonisin B₂ (FB₂), deoxynivalenol (DON), ochratoxin A (OTA) and zearaleneone (ZEN) in the samples following a QuEChERS extraction method. Eighty two percent of samples were co-contaminated with more than one group of mycotoxins. Fumonisins (FB₁ + FB₂) had the highest percentage occurrence in all 101 samples (100%) whereas OTA had the lowest (5%). For all three villages the mean concentration of FB₁ was lowest in samples taken from time point 2. Conversely, In Kigwa village there was a distinct trend that AFB₁ mean concentration was highest in samples taken from time point 2. DON concentration did not differ greatly between time points but the percentage occurrence varied between villages, most notably in Kigwa where 0% of samples tested positive. ZEN occurrence and mean concentration was highest in Kikelelwa. The results suggest that mycotoxin contamination in maize can vary based on season and agro-ecological zones. The high occurrence of multiple mycotoxins found in maize porridge, a common weaning food in Tanzania, presents a potential increase in the risk of exposure and significant health implications in children.     

Multiple mycotoxin co-occurrence in maize grown in three agro-ecological zones of Tanzania

In this study, the co-occurrence of multiple mycotoxins in maize kernels collected from 300 households' stores in three agro-ecological zones in Tanzania was evaluated by using ultra high performance liquid chromatography/time-of-flight mass spectrometry (TOFMS) with a QuEChERS-based procedure as sample treatment. This method was validated for the analysis of the main eleven mycotoxins of health concern that can occur in maize: aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁), aflatoxin G₂ (AFG₂), ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B₁ (FB₁), fumonisin B₂ (FB₂), HT-2 toxin, T-2 toxin and zearalenone (ZEN). From each zone one major maize producing district for home consumption was chosen and 20 villages for each district were randomly selected for sampling. All mycotoxins of health concern, except for T-2 toxin, were detected in the maize samples. Particularly high levels of AFB₁ (50%; 3–1,081 μg kg⁻¹), FB₁ (73%; 16–18,184 μg kg⁻¹), FB₂ (48%; 178–38,217 μg kg⁻¹) and DON (63%; 68–2,196 μg kg⁻¹) were observed. Some samples exceeded the maximum limits set in Tanzania for aflatoxins or in European regulations for other mycotoxins in unprocessed maize. Eighty seven percent of samples were contaminated with more than one mycotoxin, with 45% of samples co-contaminated by carcinogenic mycotoxins, aflatoxins and fumonisins. Significant differences in contamination pattern were observed among the three agro-ecological zones. The high incidence and at high levels (for some) of these mycotoxins in maize may have serious implications on the health of the consumers since maize constitute the staple food of most Tanzanian population. Effective strategies targeting more than one mycotoxin are encouraged to reduce contamination of maize with mycotoxins.     

Effect of gamma radiation on reduction of mycotoxins in black pepper

Gamma ray was applied to reduce mycotoxins, i.e. ochratoxin A (OTA) and aflatoxins B₁, B₂, G₁ and G₂ (AFB₁, AFB₂, AFG₁ and AFG₂) in black pepper. Response surface methodology (RSM) was applied to evaluate the effect of dose of gamma ray ranging from 0 to 60 kGy and mycotoxin concentration ranging from 10 to 100 ng g⁻¹ on the mycotoxin reduction. The maximum reduction was found at 60 kGy which was 52%, 43%, 24%, 40% and 36% for OTA, AFB₁, AFB₂, AFG₁ and AFG₂, respectively. Results showed the gamma rays even at 60 kGy were not effective in completely destroying of ochratoxin and aflatoxins.     

Detection of aflatoxin B1 by aptamer-based biosensor using PAMAM dendrimers as immobilization platform

We report an aptamer-based biosensor for detection of aflatoxin B₁ (AFB₁), a mycotoxin identified as contaminant in food. The sensor is assembled in a multilayer framework that utilizes cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) for acquiring the signal response by means of redox indicators: K[Fe(CN)₆]^−3/−4. Poly (amidoamine) dendrimers of fourth generation (PAMAM G4) immobilized on gold electrode covered by cystamine, were employed for attachment of single stranded amino-modified DNA aptamers specific to AFB₁. The cystamine-dendrimers (Cys-PAMAM) layers were compared with other immobilization platforms such as cystamine (Cys), 11-mercaptoundecanoic acid (MUA) and 11-mercaptoundecanoic acid-dendrimers (MUA-PAMAM), being the first approach the most appropriate for producing sensitive and reproducible signal in the range of concentrations 0.1–10 nM AFB₁. The sensor was validated in certified contaminated peanuts extract as well as in spiked samples of peanuts-corn snacks and the sensing response was evaluated and compared in terms of the matrix effect. The aptamer specificity was analyzed by testing the sensor in other mycotoxins such as aflatoxin B₂ (AFB₂) and ochratoxin A (OTA). The limit of detection achieved by this sensor was LOD = 0.40 ± 0.03 nM, it was regenerable in 0.2 M glycine-HCl and it did not lose its stability up to 60 h storing at 4 °C. Atomic Force Microscopy (AFM) studies were also performed for illustrating individual steps of biosensor assembly.     

Natural incidence of aflatoxins,ochratoxin A and zearalenone in chicken meat and eggs

Aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZEN) were analyzed in 115 chicken meat and 80 eggs samples, collected from central areas of Punjab, Pakistan. The study was carried out using reverse phase HPLC, equipped with fluorescence detector. The results revealed that 35% samples of chicken and 28% samples of eggs were found contaminated with AFs, and maximum level of AFB₁ and total AFs was found in the liver part of chicken (layer) 7.86 and 8.01 μg/kg, respectively. Furthermore, 41% samples of chicken and 35% sample of eggs were found contaminated with OTA and maximum level 4.70 μg/kg was found in the liver part of chicken meat. However, 52% samples of meat and 32% samples of eggs were found contaminated with ZEN and maximum level 5.10 μg/kg was found in the liver part of chicken meat. The occurrence and incidence of AFs, OTA and ZEN in chicken meat and eggs are alarming and it may produce health hazards and urged the need of continuous monitoring for these toxins in chicken meat and eggs.     

Aflatoxins and ochratoxin A in Brazilian paprika

Seventy paprika samples collected in the city of São Paulo, Brazil, from January to April 2006 were analysed for aflatoxins and ochratoxin A (OTA) using an immunoaffinity column clean-up and HPLC-FLD. For aflatoxins, the limit of quantification (LOQ) were 0.23, 0.23, 0.45 and 0.45 μg/kg for AFB₁, AFB₂, AFG₁ and AFG₂, respectively. For OTA the LOQ was 0.80 μg/kg. Aflatoxins were found in 82.9% of samples and AFB₁ was detected in 61.4% at levels ranging from 0.5 to 7.3 μg/kg with mean concentration of 3.4 μg/kg. OTA was found in 85.7% at levels ranging from 0.24 to 97.2 μg/kg with mean concentration of 7.0 μg/kg.     

Natural occurrence of mycotoxins in cereals and spices commercialized in Morocco

Sixty samples of cereals (20 of corn, 20 of barley, and 20 of wheat) and 55 samples of spices (14 of paprika, 12 of ginger, 14 of cumin, and 15 of pepper) purchased from popular markets of Rabat and Salé in Morocco were analyzed for mycotoxins.Cereals samples were all analyzed for ochratoxin A (OTA). The average levels of contamination were 1.08, 0.42, and 0.17 μg/kg for corn, wheat, and barley, respectively. Samples of corn were also analyzed for zearalenone (ZEA) and fumonisin B₁ (FB₁) the average contaminations were 14 and 1930 μg/kg, respectively. Co-occurrence of OTA, FB₁, and ZEA was also checked. Spices samples were analyzed only for aflatoxins (AFs) and the average contaminations found for aflatoxin B₁ (AFB₁) were 0.09, 0.63, 2.88 and 0.03 μg/kg for black pepper, ginger, red paprika and cumin, respectively. The higher level of contamination was found in red paprika (9.68 μg/kg).The present report is the first one ever drafted on the natural co-occurrence of OTA, FB₁ and ZEA in cereals and on the occurrence of AFs in spices from Morocco.