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.     

Natural mycotoxin contamination of maize (Zea mays L.) in the South region of Brazil

The natural co-occurrence of fungal metabolites in maize samples from the South region of Brazil was studied using an LC-MS/MS based multi-mycotoxin method. All maize samples (n = 148) were contaminated with fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂). Aflatoxin B₁ (AFB₁) and aflatoxin G₁ (AFG₁) were detected in 38 and 11 samples, respectively, while zearalenone (ZEN) and deoxynivalenol (DON), which were first regulated in 2014, were found in 110 and 71 samples, respectively. Apart from regulated mycotoxins, a broad range of non-regulated metabolites, from Aspergillus, Fusarium, Alternaria, Penicillium and other microbes, were also detected in maize sample. Fusarin C, a possible carcinogenic compound to humans, produced by Fusarium species and not addressed by Brazilian legislation, was detected in 54.2% of maize samples. All analysed maize samples were found to be contaminated by at least ten different metabolites, with the largest number of metabolites found in the same sample being 51.     

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.     

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.     

Fumonisin B1 and its co-occurrence with other fusariotoxins in naturally-contaminated wheat grain

The natural occurrence of fumonisin B₁ (FB₁) and its co-occurrence with zearalenone (ZEA), T-2 toxin and deoxynivalenol (DON) were surveyed in 103 winter wheat samples collected after four to six-month storage in family barns from different locations in Serbia. All 103 samples were mycotoxin positive. The mean concentrations of all mycotoxins except ZEA were greater in 2005 than in 2007. FB₁ was detected in 82.1% and 92.0% of all samples with ranges of 750-5400 μg kg⁻¹ (mean, 2079.45 μg kg⁻¹) and 750-4900 μg kg⁻¹ (mean 918.76 μg kg⁻¹) in 2005 and 2007, respectively. Moderate positive correlations were found between FB₁ and DON concentrations (r = 0.56 in 2005 and r = 0.54 in 2007) and between FB₁ and ZEA concentrations (r = 0.48 in 2005 and r = 0.60 in 2007), while a moderate negative correlation was detected between the production of FB₁ and T-2 toxin in 2007 (r = −0.33). This is the first report of FB₁ occurrence in naturally-contaminated wheat grain and its simultaneous occurrence with ZEA, DON and T-2 toxin in Serbia. Moreover, this is one of the rare reports presenting the occurrence of FB₁ on wheat in the world.     

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.     

Screening of deoxynivalenol contamination in durum wheat by MOS-based electronic nose and identification of the relevant pattern of volatile compounds

Fungal volatile metabolites can be used as an indicator of mycotoxins occurrence in cereals. A rapid, easy-to-perform and non-invasive method using an electronic nose based on metal oxide sensors was developed to distinguish the quality of durum wheat samples in three classes based on the content of the mycotoxin deoxynivalenol (DON): class A ([DON] < 1000 μg/kg), class B (1000 ≤ [DON] ≤ 2500 μg/kg;) and class C ([DON] > 2500 μg/kg). Two different approaches were tested by performing 525 analyses of naturally contaminated durum wheat either on whole and ground kernels. Discriminant Function Analysis (DFA) provided calibration models that permitted to classify wheat samples with mean recognition percentages (R) for whole and ground kernels of 69.3% and 86.7%, respectively. Samples belonging to class A were better recognized than those belonging to classes B and C. The e-nose method applied to the analysis of ground wheat showed highest mean recognition percentage (R = 82.1%) in validation. By considering data with recognition percentage rate (R_r) higher than 80% in validation, performances of this method were further improved in terms of either mean recognition percentage (R = 90.1%) and percentage of misclassified samples (4%). An SPME-GC–MS method was also developed that allowed to characterize the pattern of volatile compounds of durum wheat samples. A positive (trichodiene, longifolene, 3-methyl butanal, tridecane, γ-caprolactone, 6,10,14-trimethyl-2-pentadecanone) or negative (hexadecane, 2,3,7-trimethyl-decane, 4,6-dimethyl-dodecane) association with DON content was observed. These results confirm that the developed e-nose method could be used as useful tool for high throughput screening of DON contamination in durum wheat.     

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.     

Aflatoxins and fumonisins in rice and maize staple cereals in Northern Vietnam and dietary exposure in different ethnic groups

Mycotoxins in food are increasingly a food safety hazard concern in particular in developing countries. This study was performed to determine the occurrence and determinants of aflatoxin and fumonisin contamination in rice and maize and to assess health risks through dietary intake exposure among ethnic minority groups in northern Vietnam. A total of 111 rice and 102 maize samples, were tested for occurrence of fungi and mycotoxins, i.e. aflatoxins (AF’s) and fuminisin B (FB). Results showed that 107 (96.4%) rice and 84 (82.4%) maize samples were contaminated by fungi. Aspergillus flavus was found in 68 (61.3%) rice and 30 (29.4%) maize samples, Aspergilus parasiticus in 40 (36.0%) rice and 27 (26.7%) maize samples. AF’s - were detected in 27 rice (24.3%) and 27 maize samples (26.4%) at minimum and maximum levels in rice of 2.06 and 77.8 ng/g and 20.5 and 110 ng/g in maize, respectively. Nine (8.1%) rice and 24 (23.5%) maize samples contained FB at ranges of 2.3–624 ng/g in rice and 5.6–89.8 ng/g in maize. Data collected through interviews and observations in households showed that type of crop, storage duration and presence of fungi, particularly mycotoxigenic fungi were important risk factors for AF’s and FB contamination. Based on daily food consumption data, the estimated average exposure dose of aflatoxin B₁(AFB₁) from rice was 21.7 ng/kg bw/day for adults and 33.7 ng/kg bw/day for children. For FB, the rice based average exposure amounted to 536 ng/kg bw/day for adults and 1019 ng/kg bw/day for children. The calculated excess risk of liver cancer incidence by ingestion of cereals containing AFB₁ was 1.5 per 100,000 adults and 2.3 per 100,000 children per year. The average intake of FB was calculated to be lower than the tolerable diet intake (TDI). Our findings highlight that rice and maize are contaminated with mycotoxins at levels representing actual health hazards for the ethnic minority groups consuming these stable cereals. Proper drying and storage conditions in households are likely to reduce the mycotoxin contamination.     

Gold nanoparticles-based lateral flow immunoassay with silver staining for simultaneous detection of fumonisin B1 and deoxynivalenol

A lateral flow immunoassay with silver staining for the simultaneous detection of fumonisin B₁ (FB₁) and deoxynivalenol (DON) in maize samples was reported. The assay was based on the competition between target mycotoxins and corresponding coating antigens immobilized on test lines for binding to limited gold nanoparticles (AuNPs)-labeled antibodies. The detection signal was further amplified by employment of silver staining on AuNPs. In the process, silver ions were catalyzed by AuNPs into metal silver that deposited on the surface of AuNPs, allowing not only the enlargement of particle dimensions of AuNPs but also a more distinguishable black coloration on the test zone. Under optimized conditions, the cut-off values of silver staining lateral flow immunoassay were 2.0 ng mL⁻¹ for FB₁ and 40 ng mL⁻¹ for DON in buffer, which was improved at least 2 times in comparison to those of AuNPs-based method. The assay was further applied to detect FB₁ and DON in naturally contaminated maize samples and a good agreement was found with the data obtained from HPLC-MS/MS.     

Mycological quality and mycotoxin contamination of Sri Lankan peppers (Piper nigrum L.) and subsequent exposure assessment

The aim of the study was to characterize the toxigenic moulds and to screen different mycotoxins in peppers (Piper nigrum L.) of Sri Lankan origin. Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger and Penicillium spp. were found to be the most dominant fungi. Characterization of the moulds was carried out in A. flavus and parasiticus agar (AFPA) and malt extract agar (MEA) in 77 black pepper (BP) and 11 white pepper (WP) samples. In total, 73% of the BP and 64% of the WP samples were contaminated with A. flavus and/or A. parasiticus (AfAp). A BP sample with water activity (a_w) 0.70 recorded the highest count of AfAp (4.3*10⁴ CFU/g). Moreover, 75% of the BP samples exceeded the safe a_w limit (0.65) set by the European Spice Association (ESA). The frequency of occurrence of A. niger in BP was 62% with counts up to 1.3*10³ CFU/g. Penicillium spp. were found in 61% and 55% of the BP and WP samples, respectively. In BP 94% of the samples had a Penicillium contamination below 10³ CFU/g. Other Aspergillus spp, found in peppers included, Aspergillus terrus, Aspergillus tamarii, Aspergillus candidus, Aspergillus penicilloides, Aspergillus sydowii and Aspergillus fumigatus. Mould counts in BP (10²–10⁴ CFU/g) were significantly higher than that of WP (<10² CFU/g). Apart from the occurrence of “classical mycotoxins” of spices, aflatoxins (<LOQ-18 μg/kg) and ochratoxin A (<LOQ-79 μg/kg), other toxins including fumonisin B1 (<LOQ-135 μg/kg), sterigmatocystin (<LOQ-49 μg/kg) and citrinin (<LOQ-112 μg/kg) were detected in peppers. In total, 63% of the BP samples were contaminated with at least one mycotoxin. Mycotoxin contamination in WP was significantly less compared to BP. The exposure to aflatoxins and ochratoxin A by consuming pepper remains harmless considering the existing pepper dietary intake data of the Sri Lankan population.     

Simultaneous determination of Fusarium mycotoxins in wheat grain from Morocco by liquid chromatography coupled to triple quadrupole mass spectrometry

In the present study, eighteen (18) mycotoxin produced by the genus Fusarium (fumonisins (FB1, FB2 and FB3), type-B trichothecenes (NIV, DON, FUS-X, 3Ac-DON and 15Ac-DON), type-A trichothecenes (NEO, DAS, T2 and HT2), zearalenone (ZEA), beauvericin (BEA), and enniatins (ENA, ENA₁, ENB and ENB₁)) were monitored in different samples of wheat grain commercialized in Morocco. A liquid chromatography coupled to triple quadrupole mass spectrometry method previous matrix solid phase dispersion extraction was used for sample analysis. A total of eighty (80) samples of durum wheat were collected in different local markets from several areas in Morocco. Analytical results showed that 54 out of 80 total wheat samples (68%) were contaminated. The mycotoxins found were ENA, ENA₁, ENB and ENB₁, DON and BEA. The rest of investigated mycotoxins were below the limits of quantification. In positive samples, enniatins levels ranged between 2.5 and 2570 μg/kg. DON levels ranged between 121 and 1480 μg/kg and BEA levels were between 5.4 and 16 μg/kg. Among enniatins, ENB was predominant with a frequency of 61%. Co-presence of DON, enniatins and BEA from durum wheat from Morocco was found for the first time.     

Mycotoxin contamination in corn smut (Ustilago maydis) galls in the field and in the commercial food products

Corn infected with Ustilago maydis, causal agent of common smut disease, produces galls that are used as food in certain cultures, but may be contaminated with mycotoxins. The objective of this study was to determine mycotoxin levels in common smut galls (CSGs) collected from the field at corn ear reproductive stages R1 through R5 and in commercial CSGs products. The study was conducted in 2012 and 2013. A simple extraction method for five mycotoxins was devised and the results showed the presence of these compounds in CSGs in corn during ear development at various physiological stages. Fumonisin was the major mycotoxin in CSG samples in both 2012 (63%, ≤150.7 μg g⁻¹) and 2013 (46.9%, ≤20.9 μg g⁻¹); followed by aflatoxin (2012: 2%, ≤14.7 ng g⁻¹; 2013: 30.6%, ≤10.8 ng g⁻¹) and zearalenone (2012: ≤41.70 ng g⁻¹; 2013: ≤12.40 ng g⁻¹). Deoxynivalenol (DON) was only detected in 2012 (≤1.6 μg g⁻¹), and cyclopiazonic acid was only detected in 2013 (≤3.18 μg g⁻¹). Commercial canned and fresh CSG samples also contained detectable amounts of mycotoxins including aflatoxin, fumonisin, CPA, and DON. Aspergillus flavus was isolated from selected 2013 CSG field samples at R2 or older (0–1.6 × 10⁶ cfu/g), whereas Fusarium spp were isolated at R1 or older (0–7.5 × 10⁷ cfu/g). These results indicate that CSGs can be infected with mycotoxigenic fungi and contaminated with mycotoxins. The incidence of mycotoxins in commercially available CSG products was highly variable and warrants further study.     

Co-occurrence and evaluation of mycotoxins in organic and conventional rye grain and products

A study on the co-occurrence of Fusarium toxins in conventional and organic grain and derived products was carried out. A total of 117 samples were collected during the period 2009–2012. Eight mycotoxins were determined using the LC-MS/MS method. Among the investigated mycotoxins, four were of major importance: DON, ZEN, T-2 and HT-2. DON was present at the highest concentration in both the agricultural systems, with its maximum level of 254 ± 23 μg kg⁻¹ being present in conventional rye grain. The co-occurrence of two or more mycotoxins was observed in more than 50% of samples, with the most frequent combination being DON + ZEN. The correlation between the concentrations of T-2 and HT-2, DON and ZEN, as well as T-2 and ZEN was confirmed statistically. The concentration of DON, HT-2 and T-2 was significantly higher in conventional products. Also the higher level of ZEN in organic grain in comparison to derived products was significant. None of the samples contained DAS, while NlV, MAS and 3ADON concentrations were close to the detection limits.     

Aflatoxin contamination of dried red chilies: Contrasts between the United States and Nigeria,two markets differing in regulation enforcement

Dried red chilies are among the world’s most consumed spices. From farm to fork, chilies go through cropping, harvest, drying, processing and storage. Chilies are susceptible to infection by aflatoxin producing fungi and subsequent contamination by aflatoxins at every stage. Aflatoxins are highly regulated, hepatotoxic carcinogens produced by fungi in Aspergillus section Flavi. The current study examined prevalence of aflatoxin B₁ (AFB₁) in chilies from markets across the United States (US) and Nigeria, and determined predisposition of chilies to aflatoxins post-harvest. Aflatoxin B₁ was detected in 64% chilies from US markets (n = 169), and 93% of Nigerian chilies (n = 55) with a commercial lateral flow assay (Limit of Detection = 2 μg/kg). Two percent of US samples exceeded the aflatoxin regulatory limit of 20 μg/kg, while the highest concentration detected was 94.9 μg/kg. Aspergillus spp. could be recovered only from 40% of samples from the US, and aflatoxin levels did not correlate with quantities of Aspergillus section Flavi (Colony Forming Units g⁻¹), suggesting fungi associated with chilies in US markets were killed during processing. Both average AFB₁ concentrations and fungal quantities were significantly higher (p < 0.01) in Nigerian chilies. The most contaminated sample contained 156 μg/kg AFB₁. Aflatoxin concentrations in Nigerian chilies increased as an exponential function of the quantities of Aspergillus section Flavi (r² = 0.76). Results indicate that high rates of chili consumption may be associated with unacceptable aflatoxin exposure.     

A minor survey of deoxynivalenol in Fusarium infected wheat from Yangtze–Huaihe river basin region in China

Deoxynivalenol (DON) is frequently present in infected cereals such as wheat, barley and maize. Fusarium asiaticum and Fusarium graminearium are the key fungal species which produces DON, when they infect wheat in China. Our present study is to do a minor survey on the presence of DON in the highly infected wheat regions from Jiang su and An hui province, China, harvested during the year 2010. A total of 56 wheat samples which are naturally infected by Fusarium sp., of which 35 samples from Jiang su province and 21 samples from An hui province were taken up for the study. The samples were analyzed for the presence of DON by using high performance liquid chromatography (HPLC) combined with ultraviolet detection. The recoveries of DON from the spiked samples (500–15,000 μg/kg) were obtained in the range of 85.7–90.2%, with the average relative standard deviation of 2.7%. The average percentage of contamination in all the samples was 89.3%, with the DON concentration ranging between 259 and 4975 μg/kg, and with the mean of 1962 μg/kg. According to the Chinese standard limits for DON, nearly 70% of the samples were above the maximum tolerable level of 1000 μg/kg. However, only 44% of the samples exceeded the European commission limits for unprocessed wheat of 1750 μg/kg. Regions where there was higher level of Fusarium sp. contamination due to climatic changes like heavy rainfall with high humidity, showed the presence of higher levels of DON in the samples. Cropping of Fusarium resistant wheat cultivars like Sumai 3 in the regions where the wheat is highly susceptible for the Fusarium contamination could help in the reduction of contamination in wheat.     

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.     

Multimycotoxin analysis of sorghum (Sorghum bicolor L. Moench) and finger millet (Eleusine coracana L. Garten) from Ethiopia

The natural contamination of sorghum and finger millet by toxigenic fungi and associated mycotoxins has been studied. All the tested sorghum and finger millet samples were found to be contaminated by Fusarium and Aspergillus species. Sorghum was considerably more likely to be contaminated by both genera than finger millet. Penicillium, Alternaria, Rhizopus and Epicoccum species were also present in both grains albeit at lower frequencies. Multimycotoxin analysis using LC–MS/MS revealed the contamination of sorghum and finger millet by 84 and 62 metabolites, respectively. The prevalence of major mycotoxins was lower than 15% in sorghum except zearalenone that occurred in one third of the samples at average level of 44 μg/kg. In finger millet major mycotoxins occurred at a prevalence of 6–52% with zearalenone being the dominant and occurring at average level of 76 μg/kg. Aflatoxins B₁, B₂, G₁, G₂ and M₁ were detected in at least one sorghum sample while only aflatoxins B₁ and G₁ were present in finger millet samples. The average aflatoxins B₁ and G₁ concentrations in sorghum have been higher than European standards. But the level of B₂, G₂ and M₁ in sorghum and that of B₁ and G₁ in finger millet have been lower. Apart from aflatoxin precursors and other Fusarium metabolites, a broad range of additional metabolites were detected in sorghum and finger millet.     

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.