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1.
In this survey aflatoxin, M1 was quantified in raw and processed milk from various areas of two big cities of Punjab province, i.e. Lahore and Multan. The results indicated that approximately 90% of the raw milk samples collected from Lahore city was contaminated with aflatoxin M1. Similarly, around 92% of the raw milk samples collected from Multan city was contaminated with aflatoxin M1. All samples of processed milk and tea whiteners were contaminated and 56% of the contaminated processed milk samples and 66% of the contaminated tea whitener samples were violating the maximum limits. The dietary exposure data of AFM1 among six different groups was calculated, which indicated that the male children population was the most vulnerable group to AFM1, up to 6.68 ng L?1 per day and the least affected one was the female group above 20 years of age with 1.13 ng L?1 per day.  相似文献   

2.
Aflatoxin M1 is one of the most common toxic natural substances found worldwide. It metabolizes from aflatoxin B1 that is present in the diet of mammals. In this study, 84 milk samples were investigated in total, and 63 (75 %) were contaminated with aflatoxin M1 above the limit of detection. No difference was observed between the samples from organic and conventional systems (0.021 vs. 0.018 µg/kg; p > 0.05). There was no difference between pasteurized and raw milk samples (0.018 vs. 0.020 µg/kg; p > 0.05). None of the samples contained aflatoxin M1 above the maximum level permitted by Brazilian Legislation (0.5 µg/kg for fluid milk). The estimated daily intake (EDI) of aflatoxin M1 through organic and conventional milk consumption was also evaluated. In this study, the EDI-values for aflatoxin M1 did not pose a toxicological risk for the population. To our best knowledge, this is the first report on aflatoxin M1 levels in organic milk from Brazil.  相似文献   

3.
An enzyme‐linked immunosorbent assay (ELISA) using a monoclonal antibody was established to detect aflatoxin B1 (AFB1) in tea. The antibody was prepared from a hybridoma derived by fusing Sp2/0‐Ag14 myeloma cells and immunised spleen B cells. The effects from pH, ionic strength, and organic solvents on immunoassay were optimised and the 50% inhibition (IC50) value was 0.057 ± 0.007 ng mL?1. Spiked black and green tea samples at 10, 20 and 50 ng g?1 levels of AFB1 were detected with this proposed ELISA. The recoveries for black tea samples ranged from 68.5% to 117.7% and 73.5 to 114.3% for green tea samples. This immunoassay showed no cross‐reactions with other mycotoxin family but good recognition with related aflatoxins. These results indicate that the ELISA assay could be used as a screening method for aflatoxin detection in tea samples.  相似文献   

4.
Aflatoxin contents in 12 types of herbal teas were determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. Forty eight samples were collected from four local herbal shops in Manisa, Turkey. Of the 48 samples analyzed, 43 were aflatoxin positive. The highest concentration of aflatoxin (34.18 µg/kg) was determined in a sample of camomile tea. The occurrence of AFB1, B2, G1 and G2 was found in samples at levels of 54, 29, 71 and 46 %, respectively. Aflatoxin B1, B2, G1 and G2 contamination levels varied from 0 to 14.2, 0 to 12.4, 0 to 13.5 and 0 to 28.7 µg/kg, respectively. Aflatoxin was not detected in five samples consisting of linseed, lime and fennel tea.  相似文献   

5.
A total of 61 samples comprising sunflower seeds (40) and unrefined sunflower oils (21) samples collected randomly from Singida, Tanzania were analysed by Reverse Phase-high performance liquid chromatography (RP-HPLC). 15% (6/40) of the seed samples were contaminated with aflatoxin B1 ranging from limit of detection (LOD) to 218 ng g?1 with three of them exceeding the European Commission/European Union (EC/EU) and Tanzania Bureau of Standards (TBS)/Tanzania Food and Drug Authority (TFDA) maximum limits of 2 ng g?1 for AFB1 in oilseeds. The levels of total aflatoxins (AFT) in seeds ranged from LOD to 243 ng g?1. Other aflatoxins, except AFG2, were also detected. For the unrefined sunflower oils, the levels of AFB1 ranged from LOD to 2.56 ng mL?1. About 80.9% (17/21) of the analysed oil samples contained AFB1 of which 17.65% (3/17) exceeded the EC/EU and TBS/TFDA maximum limits of 2 ng mL?1. Other aflatoxins were also detected in the oils. The measured levels indicate there is a need for food quality education among food processors.  相似文献   

6.
The peanut supply chain in Malaysia is dominated by three main stakeholders (importers, manufacturers, retailers). The present study aimed to determine the levels and critical points of aflatoxin and fungal contamination in peanuts along the supply chain. Specifically, two types of raw peanuts and six types of peanut-based products were collected (N = 178). Samples were analysed for aflatoxins by using high-performance liquid chromatography. Results revealed that the aflatoxin contamination was significantly higher (P ≤ 0.05) in raw peanuts and peanut-based products from the retailers. However, there was no significant difference (P ≥ 0.05) in fungal contamination for both types of peanuts except for the total fungal count in raw peanuts from the retailers. Furthermore, raw peanut kernels from the retailers were the most contaminated ones ranged from <LOD to 1021.4 µg/kg (mean: 120.7 µg/kg, median: 1.4 µg/kg) followed by the samples collected from the manufacturers which was ranged from < LOD to 181.9 µg/kg (mean: 20.5 µg/kg, median: 0.0 µg/kg). About 38% and 22% of the samples from the retailers and manufacturers were found to have exceeded the Malaysian Regulation limit (raw peanuts:15 µg/kg; peanut-based products:10 µg/kg), respectively. In contrast, no aflatoxins were detected in samples from the importers. On the other hand, 15.0% and 5.9% of peanut-based products from retailers and manufacturers, respectively, were found to have exceeded the limit. Fungal contamination (0.3–3.6 log CFU/g) was relatively higher in raw peanuts compared to that of peanut-based products (0.6–2.7 log CFU/g). In conclusion, the manufacturers and retailers were the critical points for aflatoxin contamination in peanuts. However, fungal contamination was more critical in the raw peanuts compared to peanut-based products. The study was limited by a minimal number of samples from the importer. Therefore, further investigations on a larger sample size should be conducted to confirm the findings in this present study.  相似文献   

7.
The objective of the present study was to assess the degree of exposure of broiler chicken to mycotoxins through naturally contaminated feed and the hygienic quality of feeds. For this purpose the total fungal count and occurrence of fumonisins and aflatoxins were evaluated in four feed types intended for broilers (n?=?158), collected from a poultry breeding farm in northern Paraná State, Brazil. In most feed samples (94 % pre-starter, 91 % starter, 99 % grower and 97 % finisher feeds) the total mould and yeast counts were below 1.0?×?104 CFU/g, the maximum limit established to assure a good hygienic quality of the product. Fumonisins were detected in 94.9 % feed samples at mean levels ranging from 0.52 mg/kg (finisher) to 0.68 mg/kg (pre-starter and grower), while aflatoxins were detected in 72.1 % feed samples at mean levels ranging from 0.0022 mg/kg (pre-starter) to 0.0064 mg/kg (grower). The maximum estimated daily intake of fumonisin B1 for broilers (0.057 mg/kg body weight/day) was below the Lowest Observed Adverse Effect Level (2 mg/kg bw/day). Concerning aflatoxins, most of the positive samples (97 %) showed aflatoxin levels below the maximum limit allowed by the European Commission 0.02 mg aflatoxin B1/kg. Nevertheless, a rigorous monitoring program of the feed producing chain is essential in order to minimize human health hazards. To our knowledge, this is the first report on the degree of exposure of broilers to mycotoxins through naturally contaminated feed in Brazil.  相似文献   

8.
Method validation for quantitative analysis of aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZEA) in cereals using HPLC with fluorescence detector (FLD) is described. Mycotoxins were extracted with methanol?:?water (80?:?20) and purified with a multifunctional AOZ immunoaffinity column before HPLC analysis. The validation of the analytical method was performed to establish the following parameters: specificity, selectivity, linearity, limits of detection (LOD) and quantification (LOQ), accuracy, precision (within- and between-day variability), stability, robustness, measurement of performance, and measurement of uncertainty. Calibration curves were linear (r?>?0.999) over the concentration range, from the LOQ to 26, 40 and 400?ng/g for AFs, OTA and ZEA, respectively. LOD and LOQ were 0.0125 and 0.05?ng/g for aflatoxin B1 (AFB1) and G1 (AFG1), 0.0037 and 0.015?ng/g for aflatoxin B2 (AFB2) and G2 (AFG2), as well as 0.05 and 0.2?ng/g for OTA and 0.5 and 2?ng/g for ZEA, respectively. The mean recovery values were 77–104% for different concentrations of AFs, OTA and ZEA in spiked cereal samples. Both intra- and inter-day accuracy and precision were within acceptable limits. This method was successfully applied for the simultaneous determination of mycotoxins for 60 cereal samples collected from Malaysian markets. Fifty per cent of the cereal samples were contaminated with at least one of these mycotoxins, at a level greater than the LOD. Only one wheat sample and two rice samples were contaminated with levels greater than the European Union regulatory limits for AFs and OTA (4 and 5?ng/g). The means and ranges of mycotoxins obtained for the cereal samples were 0.4?ng/g and 0.01–5.9?ng/g for total AFs; 0.18?ng/g and 0.03–5.3?ng/g for OTA; and 2.8?ng/g and 2.4–73.1?ng/g for ZEA, respectively. The results indicate that the method is suitable for the simultaneous determination of AFs, OTA and ZEA in cereals and is suitable for routine analysis.  相似文献   

9.
A modified QuEChERS method for the determination of 16 phthalate esters (PAEs) in tea samples using GC-MS/MS was developed and validated. The kinds and amounts of adsorbents were optimised, and the crude extracts were purified using primary secondary amine (PSA), graphitised carbon black (GCB) and anhydrous magnesium sulphate (MgSO4). Compared with extraction without matrix hydration, the addition of water could achieve higher extraction efficiency. The recoveries for PAEs obtained against matrix-matched standards at spiking levels of 50, 200 and 500 μg kg–1 ranged from 84.7% to 112.7% with relative standard deviations below 20% (n = 6) for all cases. Limits of detection (0.6–36.0 μg kg–1) and quantitation (2.0–120.0 μg kg–1) were achieved using the proposed method for all PAEs. A total of 105 tea samples were found to be contaminated with PAEs.  相似文献   

10.
Aflatoxin levels in hazelnut samples obtained from exporter companies were monitored over a 3-year period. A total of 3188 samples of raw and processed hazelnuts were analysed using an HPLC method. The total aflatoxin content of the contaminated samples was in the range of 0.02–78.98?µg?kg?1 for hazelnut kernels, 0.07–43.59?µg?kg?1 for roasted hazelnut kernels, 0.02–39.17?µg?kg?1 for roasted sliced hazelnut kernels, and 0.02–11.20?µg?kg?1 for hazelnut purees, respectively, showing that the variations of aflatoxin contamination were very high. The results of aflatoxin analysis revealed that the aflatoxin contamination in the hazelnut samples was at a tolerable level. A total of 3147 samples were contaminated with aflatoxins, although below the legal limits. However, the aflatoxin contents of 41 samples exceeded the legal limits. Therefore, aflatoxin contents of hazelnuts should be monitored regularly to minimise the risk of aflatoxin hazard, and pre- and post-harvest strategies should be developed to prevent aflatoxin formation.  相似文献   

11.
Method validation for quantitative analysis of aflatoxins (AFs), ochratoxin A (OTA) and zearalenone (ZEA) in cereals using HPLC with fluorescence detector (FLD) is described. Mycotoxins were extracted with methanol : water (80 : 20) and purified with a multifunctional AOZ immunoaffinity column before HPLC analysis. The validation of the analytical method was performed to establish the following parameters: specificity, selectivity, linearity, limits of detection (LOD) and quantification (LOQ), accuracy, precision (within- and between-day variability), stability, robustness, measurement of performance, and measurement of uncertainty. Calibration curves were linear (r > 0.999) over the concentration range, from the LOQ to 26, 40 and 400 ng/g for AFs, OTA and ZEA, respectively. LOD and LOQ were 0.0125 and 0.05 ng/g for aflatoxin B1 (AFB1) and G1 (AFG1), 0.0037 and 0.015 ng/g for aflatoxin B2 (AFB2) and G2 (AFG2), as well as 0.05 and 0.2 ng/g for OTA and 0.5 and 2 ng/g for ZEA, respectively. The mean recovery values were 77-104% for different concentrations of AFs, OTA and ZEA in spiked cereal samples. Both intra- and inter-day accuracy and precision were within acceptable limits. This method was successfully applied for the simultaneous determination of mycotoxins for 60 cereal samples collected from Malaysian markets. Fifty per cent of the cereal samples were contaminated with at least one of these mycotoxins, at a level greater than the LOD. Only one wheat sample and two rice samples were contaminated with levels greater than the European Union regulatory limits for AFs and OTA (4 and 5 ng/g). The means and ranges of mycotoxins obtained for the cereal samples were 0.4 ng/g and 0.01-5.9 ng/g for total AFs; 0.18 ng/g and 0.03-5.3 ng/g for OTA; and 2.8 ng/g and 2.4-73.1 ng/g for ZEA, respectively. The results indicate that the method is suitable for the simultaneous determination of AFs, OTA and ZEA in cereals and is suitable for routine analysis.  相似文献   

12.
This study aimed to assess aflatoxin and fumonisin intake through corn tortilla consumption in Veracruz city. Between October 2013 and February 2015, a total of 120 corn tortilla samples (2 kg samples, 40 samples per year) were randomly collected. Aflatoxins and fumonisins were quantified by high performance liquid chromatography coupled with a fluorescence detector. A probability density function (PDF) was used for describing corn tortilla intake, body weight of the Veracruz city population, mycotoxin content of corn tortilla samples and estimated mycotoxin daily intake. The Monte Carlo method with 10,000 iterations was employed to assess the population exposure risk. The highest level of total aflatoxins (AFT) was 22.17 μg kg?1, and 526.6 μg kg?1 for fumonisins B1 plus B2, with 85% and 90% of contaminated samples respectively. Up to 69.7 % of the population was estimated to consume a higher aflatoxin dose than that recommended by the JECFA (1 ng kg?1 of body weight per day); it was found that the recommended dose was exceeded to a greater extent in the male population, due to higher consumption of corn. The risk of fumonisin intake was less than 5 % due to the low presence and levels of these toxins in corn tortillas. The results suggest that corn tortilla consumers are at dietary risk caused by AFT contamination; this information should be considered when taking action to protect public health.  相似文献   

13.
The development of screening methodologies for a rapid identification of crops contaminated with aflatoxin is of great interest to agro-food industry. The objective of this work was to develop an image algorithm able to identify bright greenish yellow fluorescence (BGYF) on pistachio nuts and cashews. Previous researchers established that the presence of BGYF indicates that there is a high probability of aflatoxin contamination. Since BGYF is not a definitive indicator of aflatoxin contamination, samples emitting fluorescence should be removed and tested for aflatoxins by chemical means. This study, conducted in a static way, is an important step towards the development of a new more accurate and automatic aflatoxin screening method based on a vision system. In this work, a total of 352 samples of pistachio nuts and cashews were evaluated, half of which came from lots contaminated with aflatoxin. Two images in the 410–600 nm optical range were acquired for each sample. Imaging algorithms were developed to identify samples with fluorescent stains caused by BGYF. According to the image analysis results, nut samples were classified into two groups: fluorescent stains (FS) and non-fluorescent stains. Both BGYF and non-fluorescent samples were analyzed for aflatoxin. The laboratory analysis results showed a high correlation with the camera classification: pistachios and cashews placed in the FS group by the vision system contained 92 % and 82 % of the total number of nuts contaminated with aflatoxin, respectively. Moreover, a discriminant analysis of reflectance data was carried out in order to select the optimal optical range to detect BGYF, both in pistachio nuts, i.e., 480 and 520 nm, and in cashews, i.e., 440 and 600 nm.  相似文献   

14.
The presence of Aspergillus section Flavi and aflatoxin (AF) contamination was investigated in 112 samples of peanuts, almonds and dried figs collected in Algeria. The occurrence of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) in different commodities has been determined with a sensitive method based on high performance liquid chromatography (HPLC) coupled with fluorescence detection with post-column photochemical derivatisation. Analytical results indicated that 28 samples of peanuts, 16 samples of almonds and 26 samples of dried figs contained detectable levels of AFs. A total of 69 samples (61.6%) were contaminated with AFB1 ranging from the limit of quantification to 174 µg kg?1. AFB2 was found in 12 samples (10.7%) and varied from 0.18 to 193 µg kg?1. Seven samples revealed AF concentrations lower than the limit of quantification. Eleven peanut and fourteen dried fig samples exceeded the European maximum limits for AFB1.  相似文献   

15.
Wheat is an important cereal but it is often contaminated with mycotoxins. The natural occurrence of aflatoxin B1 (AFB1) and sterigmatocystin (STC) was determined in 178 food samples (32 wheat samples and 146 wheat products) purchased from Chinese supermarkets. The methodology was validated, the wheat and wheat products samples were treated with a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). From these samples 18.8% of wheat and 8.2% of cracker samples were contaminated with AFB1. Mean levels were 0.06 µg/kg and 0.05µg/kg, respectively. There was no AFB1 contamination in white bread or whole meal bread. Meanwhile 53.1% of wheat, 59.2% of crackers, 20.8% of white bread and 16% of whole meal bread samples were contaminated with STC. The mean levels were 0.07, 0.79, 0.12 and 0.12 µg/kg respectively. Although the levels were low, this demonstrates the need for more comprehensive surveys for these two mycotoxins in wheat and wheat products from China.  相似文献   

16.
In this study, total number of samples analysed were 20 packages of sesame and 20 cans of peanut butter, which were collected from Ankara local markets, Turkey. Extraction and determination of aflatoxins have been made by immunoaffinity column technique and high-performance liquid chromatography (HPLC) method. Mean levels (±SE) of aflatoxins B1, B2, G1 were found to be 15.756±3.129 ng/g, 1.232±0.244 ng/g and 9.689±1.005 ng/g, respectively in peanut butter samples. Regarding the sesame samples, mean level of aflatoxin G1 was found to be 0.754±0.213 ng/g. Our data revealed that while aflatoxin levels found in sesame samples were within the Turkish Food Codex (TFC) values, for peanut butter samples, they were higher than the TFC values.  相似文献   

17.
A survey was carried out to determine the co-occurrence of ochratoxin A and aflatoxin B1 in dried figs from Turkey. Samples from two seasons of crops (2003 and 2004) intended for export to the European Union and the 2004 crop obtained from the domestic Turkish market were analyzed. Affinity column cleanup methods were employed for determining separately ochratoxin A and aflatoxin B1, but for ochratoxin A an alkaline extraction procedure was employed (in contrast to the conventionally employed acidic extraction), which gave consistently higher toxin recovery. In-house validation of the ochratoxin A method gave a limit of detection of 0.15 ng/g and a limit of quantification of 0.5 ng/g with a repeatability of 5.8% in the range 5 to 10 ng/g (with a mean recovery of 94% for spiked samples). Positive results for ochratoxin A were confirmed by liquid chromatography-mass spectrometry. For the 2003 export figs (58 samples), 7 samples contained only aflatoxin B1, 2 samples contained only ochratoxin A, and 2 samples contained both toxins (with maximum concentrations of 35.1 ng/g for aflatoxin B1 and 13.0 ng/g for ochratoxin A). Similarly for the 2004 export figs (41 samples), 16 samples contained only aflatoxin B1, 4 samples contained only ochratoxin A, and 2 samples contained both toxins (with maximum concentrations of 20.6 ng/g for aflatoxin B1 and 26.3 ng/g for ochratoxin A). Of 20 retail samples of dried figs from Turkey, only one sample contained ochratoxin A (2.0 ng/g) and none were contaminated with aflatoxin B1. This survey revealed a 14 to 15% incidence of occurrence of ochratoxin A for 2 years, which is higher than previously reported.  相似文献   

18.
Response surface methodology was applied to optimise the aflatoxin reduction in both naturally and artificially contaminated samples using dry oven. The effect of initial aflatoxin concentration (0–400 ng g?1), heating time (30–120 min) and temperature (90–150 °C) was evaluated. The maximum reduction of AFB1 (78.4%) and AFB2 (57.3%) of artificially contaminated samples with initial aflatoxin concentration of 237 and 68 ng g?1, and those of AFG1 (73.9%) and AFG2 (75.2%) with initial aflatoxin concentration of 215 and 75 ng g?1 was obtained at 150 °C. The maximum reduction of AFB1 (80.2%) and AFB2 (69.7%) of naturally contaminated samples with initial aflatoxin concentration of 174 and 25 ng g?1 was obtained at 150 °C and 130 °C, respectively.  相似文献   

19.
Polycyclic aromatic hydrocarbons (PAHs) are food-processing contaminants considered to be carcinogenic and genotoxic. Due to its drying process stage, teas may be contaminated with PAHs. The aim of the study was to validate an analytical method involving QuEChERS and HPLC-FLD for the determination of PAH4 in teas and evaluate the contamination levels in 10 different types of teas from Brazil. Recoveries varied from 54% to 99% and relative standard deviations from 1% to 21%. Limits of detection and quantification were from 0.03 to 0.3 µg/kg and 0.1 to 0.5 µg/kg, respectively. Mate tea presented the highest PAH levels, with PAH4 varying from 194 to 1795 µg/kg; followed by black (1.8–186 µg/kg), white (24–119 µg/kg), and green teas (3.1–92 µg/kg). Teas with lowest PAH4 were strawberry, lemongrass, peppermint, and boldo. Only trace levels of PAHs were detected in tea infusions, so apparently it would not affect PAH intake by Brazilian population.  相似文献   

20.
This study was conducted to assess major Aspergillus species and aflatoxins associated with groundnut seeds and cake in Eastern Ethiopia and evaluate growers’ management practices. A total of 160 groundnut seed samples from farmers’ stores and 50 groundnut cake samples from cafe and restaurants were collected. Fungal isolation was done from groundnut seed samples. Aspergillus flavus was the dominant species followed by Aspergillus parasiticus. Aflatoxin analyses of groundnut seed samples were performed using ultra performance liquid chromatography; 22.5% and 41.3% of samples were positive, with total aflatoxin concentrations of 786 and 3135 ng g?1 from 2013/2014 and 2014/2015 samples, respectively. The level of specific aflatoxin concentration varied between 0.1 and 2526 ng g?1 for B2 and B1, respectively. Among contaminated samples of groundnut cake, 68% exhibited aflatoxin concentration below 20 ng g?1, while as high as 158 ng g?1 aflatoxin B1 was recorded. The study confirms high contamination of groundnut products in East Ethiopia.  相似文献   

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