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1.
A total of 85 nuts and their products marketed in South Korea were assessed for aflatoxins using a monitoring scheme consisting of enzyme-linked immunosorbent assay (ELISA) for rapid screening, high performance liquid chromatography (HPLC) for quantification and LC–mass spectrometry (MS) for confirmation. Thirty-one out of 85 samples gave ELISA readings above 0.06 and were screened as possible positive samples. Aflatoxin contents of possible positive samples were determined using HPLC with a detection limit of 0.08–1.25 μg/kg and a quantification limit of 0.15–2.50 μg/kg. Nine samples including 1 raw peanut, 4 roasted peanuts, 2 peanut butters, 1 pistachio and 1 seasoned assorted nut were contaminated with aflatoxins (10.6% of incidence), ranging in various levels up to 28.2 μg/kg. LC–MS analysis on contaminated samples revealed that peaks eluting at 4.4, 5.2, 9.1 and 11.9 min were confirmed as aflatoxin G1, aflatoxin B1, aflatoxin G2 and aflatoxin B2, respectively.  相似文献   

2.
Two-hundred-and-forty-one samples representing cereals, legumes, oil seeds and nuts were collected from two coastal regions in Egypt. Mouldy samples were collected from lots stored under different conditions. Forty-eight per cent ((116 samples) of the samples gave bright greenish-yellow fluorescence, whereas 8% (19 samples) contained aflatoxins. Hazel nut, soybean and cottonseed meal samples were free from aflatoxins whilst white corn, yellow corn, peanuts and almonds had relatively higher concentrations of aflatoxins than other crops. Aflatoxin B1 was present in all contaminated samples whilst G2 was found only in peanuts. Aflatoxin G1 was found only in yellow corn, paddy rice and peanut samples. High concentrations of aflatoxins were found in mouldy samples of cereals and legumes which are popular in Egyptian diets. The high concentrations of aflatoxins found in contaminated samples may be due to the method of sampling and to unfavourable storage conditions.  相似文献   

3.
The aim of this study was to determine the contamination of aflatoxins B1, B2, G1, G2 in some selected spices (n = 84) in the Kuyavian-Pomeranian province of Poland. Aflatoxins were found in 63.1 % of the analysed samples. The presence of these compounds was confirmed in all the samples of pepper, nutmeg and turmeric. The maximum content for the sum of aflatoxins B1, B2, G1, G1 exceeding the acceptable level (10 μg/kg) was 16.91 μg/kg in one sample of nutmeg and 12.1 μg/kg in one sample of pepper, whereas in one sample of nutmeg the maximum content was equal to the regulatory limit. The lowest degree of contamination was found in black pepper.  相似文献   

4.
Aflatoxins in nuts assayed by immunological methods   总被引:2,自引:0,他引:2  
 Different kinds of raw and processed nuts available in the local retail market were investigated for aflatoxin content. Total aflatoxins and aflatoxin B1 content were determined by immunoaffinity chromatography with fluorescence detection after reaction with bromine solution and by immunoenzymatic test kits. Of 29 investigated samples, 38% were contaminated. The total aflatoxin content in contaminated samples was between 1.20 μg/kg for peanuts and 5.50 μg/kg for walnuts. The concentration of aflatoxin B1 found in contaminated samples was between 0.35 μg/kg for cashew nuts and 4.04 μg/kg for walnuts. The mean recovery of total aflatoxins was 95% for the Ridascreen test and 92% for immunoaffinity chromatography with fluorescence detection. For aflatoxin B1 the mean recovery was 84%. Received: 4 March 1999 / Revised version: 17 May 1999  相似文献   

5.
This research aimed at evaluating the safety, and the type, level and prevalence of mycotoxins in grain sorghum of four sub-Saharan African (SSA) countries (Burkina Faso, Ethiopia, Mali and Sudan). A multi-analyte LC-MS/MS method for quantification of 23 mycotoxins (nivalenol, deoxynivalenol, fusarenon X, neosolaniol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, diacetoxyscirpenol, roquefortine C, HT-2 toxin, alternariol, T-2 toxin, FB1, FB2, FB3, zearalenone, aflatoxin G1, aflatoxin G2, aflatoxin B1, aflatoxin B2, sterigmatocystin, OTA, altenuene, alternariol monomethylether) was applied to different sorghum matrices. Of the 1533 analysed samples, 33% were contaminated with at least one of the following mycotoxins: aflatoxins, fumonisins, sterigmatocystin, Alternaria toxins, OTA and zearalenone. Country of origin, colour, source and collection period of sorghum samples significantly influenced the type, level and prevalence of mycotoxins. Sterigmatocystin (15%), fumonisins (17%) and aflatoxins (13%) were the most prevalent. FB1 (274 ± 585 µg/kg) had the highest mean concentration followed by FB2 (214 ± 308 µg/kg) while diacetoxyscirpenol (8.12 ± 19.2 µg/kg) and HT-2 (11.9 ± 0.00 µg/kg) had the lowest concentrations. Neosolaniol, fusarenon-X, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, T-2 toxin, nivalenol and roquefortine C were not detected in any of the samples. Sudan had the lowest prevalence and mean concentration of all mycotoxins. Pink sorghum had the highest concentrations of fumonisins and aflatoxins. Mycotoxins from Aspergillus spp. and Alternaria spp. are the mycotoxins of concern in SSA grain sorghum with regard to prevalence, concentration and possible health risk from exposure. Based on the performed risk characterisation, daily consumption of sorghum containing aflatoxins, alternariol, alternariol monomethyl ether, sterigmatocystin and OTA could result in exceeding the established health-based guidance values for these toxins.  相似文献   

6.
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   

7.
This study reports the fungal and bacterial metabolites associated with natural contamination of 38 composite samples of locally processed rice from five agro-ecological zones of Nigeria (AEZs). The samples were evaluated for the presence of microbial metabolites by LC-MS/MS. Among the identified metabolites, 63 fungal and 5 bacterial metabolites were measured at varying concentrations and occurrence levels. Fusarium toxins had the highest incidence of 79%, but occurred in low amounts with fumonisin B1 (FB1) having the highest percentage incidence of 39.5% and a mean of 18.5 µg/kg. Among the Aspergillus toxins, aflatoxins (AFs) occurred in 36.9% of the rice samples, with aflatoxin B1 (AFB1) having the highest occurrence level of 18.4% and a mean value of 5 µg/kg. About 12 metabolites had incidence levels > 50%, including beauvericin (BEA) and tryptophol, which had occurrence levels of 100%. Among the emerging toxins under evaluation by international organisations such as the European Food Safety Authority (EFSA) and the Food and Agriculture Organisation of the United Nations (FAO), citrinin, sterigmatocystin (STER) and beauvericin were detected with maximum values of 207, 125 and 131 μg/kg, respectively. This paper also reports the first documented evidence of the contamination of Nigerian rice by bacterial and Alternaria metabolites, nivalenol, kojic acid, STER, moniliformin, fusaric acid, fumonisin B3, citrinin, 3-nitropropionic acid, andrastin A, cytochalasins, emodin and physicon.  相似文献   

8.
This study presents a method validation procedure for the determination of aflatoxin B1, B2, G1, and G2 in hazelnut, hazelnut paste, walnut, peanut, pistachio, corn, and wheat. The method consisting of clean-up with immunoaffinity column, high performance liquid chromatography with postcolumn derivatization and fluorescence detection was validated in accordance with Commission Regulation 2004/882/EC. The selectivity, linearity, decision limit, detection capability, detection and quantification limits, precision, recovery, ruggedness, and measurement uncertainty of the method were determined. The limit of detection and limit of quantification values (μg/kg) were: aflatoxin B1, 0.02, 0.07; aflatoxin B2, 0.01, 0.02; aflatoxin G1, 0.02, 0.07; and aflatoxin G2, 0.01, 0.03. The relative standard deviation values for the repeatability and within-laboratory reproducibility were below 4 and 5 %, respectively. The recovery values of the spiked samples ranged from 80 to 105 %. These results complied with minimum performance criteria established by regulation 2006/401/EC. Therefore, the procedure can be implemented for the routine analysis of aflatoxins in the studied matrices.  相似文献   

9.
Mycotoxin analysis is usually carried out by high performance liquid chromatography after immunoaffinity column cleanup or in enzyme-linked immunosorbent assay tests. These methods normally involve determination of single compounds only. EU legislation already exists for the aflatoxins, ochratoxin A and patulin in food, and legislation will come into force for deoxynivalenol, zearalenone and the fumonisins in 2007. To enforce the various legal limits, it would be preferable to determine all mycotoxins by routine analysis in different types of matrices in one single extract. This would also be advantageous for HACCP control purposes. For this reason, a multi-method was developed with which 33 mycotoxins in various products could be analysed simultaneously. The mycotoxins were extracted with an acetonitrile/water mixture, diluted with water and then directly injected into a LC–MS/MS system. The mycotoxins were separated by reversed-phase HPLC and detected using an electrospray ionisation interface (ESI) and tandem MS, using MRM in the positive ion mode, to increase specificity for quality control. The following mycotoxins could be analysed in a single 30-min run: Aflatoxins B1, B2, G1 and G2, ochratoxin A, deoxynivalenol, zearalenone, T-2 toxin, HT-2 toxin, α-zearalenol, α-zearalanol, β-zearalanol, sterigmatocystin, cyclopiazonic acid, penicillic acid, fumonisins B1, B2 and B3, diacetoxyscirpenol, 3- and 15-acetyl-deoxynivalenol, zearalanone, ergotamin, ergocornin, ergocristin, α-ergocryptin, citrinin, roquefortin C, fusarenone X, nivalenol, mycophenolic acid, alternariol and alternariol monomethyl ether. The limit of quantification for the aflatoxins and ochratoxin A was 1.0 µg kg?1 and for deoxynivalenol 50 µg kg?1. The quantification limits for the other mycotoxins were in the range 10–200 µg kg?1. The matrix effect and validation data are presented for between 13 and 24 mycotoxins in peanuts, pistachios, wheat, maize, cornflakes, raisins and figs. The method has been compared with the official EU method for the determination of aflatoxins in food and relevant FAPAS rounds. The multi-mycotoxin method has been proven by the detection of more than one mycotoxin in maize, buckwheat, figs and nuts. The LC–MS/MS technique has also been applied to baby food, which is subject to lower limits for aflatoxin B1 and ochratoxin A, ergot alkaloids in naturally contaminated rye and freeze-dried silage samples.  相似文献   

10.
A survey for total aflatoxins (aflatoxins B1, B2, G1, and G2) was conducted on 88 spices and processed spice products commercialized in Korea. The presence of aflatoxins was determined by high-performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. Total aflatoxins (AFs) are detected in 12 samples (13.6% of incidence) including seven red pepper powder, two red pepper pastes (Kochujang), two curry and one ginger product. The contamination levels are 0.08–4.45 μg/kg as aflatoxin B1 and 0.08–4.66 μg/kg as AFs. The liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis on contaminated samples was conducted for the confirmation of detected aflatoxins. The 12 samples which showed aflatoxins by HPLC/FLD were confirmed as aflatoxins by LC–MS/MS.  相似文献   

11.
An easy and quick sample pretreatment method, air-assisted dispersive liquid–liquid microextraction (AA-DLLME), has been introduced for the isolation and enrichment of aflatoxins B1, B2, G1, and G2 from rice samples prior to HPLC-FLD analysis. The method has also been compared with immunoaffinity column clean-up (IAC) method. In the case of AA-DLLME, the dispersion of extractant is formed in the absence of a disperser solvent and with the help of air bubbles. Several crucial factors, including the volume and type of extraction solvent, the volume of aqueous phase, and the number of extraction cycles were studied to obtain the optimal conditions. Under the optimal conditions, the suggested technique showed linearity in the range of 0.08–10 ng/mL with low limits of detection (0.68, 0.68, 0.13, and 0.13 ng/g for aflatoxins B1, G1, B2, and G2, respectively) and good sensitivity with limits of quantification of 2.0, 2.0, 0.4, and 0.4 ng/g for aflatoxins B1, G1, B2, and G2, respectively. The proposed procedure was successfully used to evaluate aflatoxins (AFs) in rice samples and acceptable recoveries in the range of 76.0–109.3% with appropriate precision (RSD?<?14.2%) were obtained.  相似文献   

12.
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   

13.
ABSTRACT

A study was conducted to evaluate the natural occurrence of aflatoxins (AFB1, AFB2, AFG1, AFG2) in cotton seeds (n = 110) and cotton seed cake (CSC; n = 110) from Pakistan. All samples were screened by Enzyme-Linked ImmunoSorbent Assay (ELISA). Positive samples were further quantified by IAC-HPLC-FLD. Total contamination frequency and aflatoxins mean levels were 80% and 69 μg/kg in cotton seeds and the corresponding values for cotton seed cake 88% and 89 μg/kg, respectively. Aflatoxin B1was found in all positive samples and co-occurred with AFB2, AFG1, and AFG2. Sixty-four cotton seeds and 71 CSC samples contained aflatoxins levels higher than the ML set for animal feed (20 µg/kg). The results of the present study will help the regulatory authorities to formulate strategies for monitoring aflatoxins in animal feeds.  相似文献   

14.
Three class-specific monoclonal antibodies against aflatoxins were screened by a designed strategy in which aflatoxin G2 was used as competitor in the screening ELISA system. With a high cross-reactivity (65%) to aflatoxin G2, antibody 10C9 had the most similar sensitivity for five aflatoxins (AFB1, AFB2, AFG1, AFG2 and AFM1), whose I50 values were in a range of 2.1–3.2 ng ml−1. So, antibody 10C9 was selected to develop an ELISA for determination of aflatoxin B1, B2, G1, G2 and total of them in peanut samples. And spiked recoveries were from 87.5% to 102.0%. The results indicate that the ELISA developed can accurately determine total aflatoxins in samples of peanuts after the simple and rapid extraction procedure.  相似文献   

15.
The objective of this study was to determine the distribution of an economically important class of mycotoxins, the aflatoxins, in rice milling fractions. Rice plants grown under field production conditions are frequently infected with types of pathogenic fungi that produce toxic metabolites (mycotoxins). Paddy (seeds) rice from healthy plants in the field was collected and stored on a farm under humid, poorly ventilated conditions. Samples were milled into four fractions (hulls, brown rice, bran and white rice) and analysed for aflatoxins (B1, B2, G1 and G2) using a validated method. Rice fractions from healthy plants, which contained low levels of aflatoxins (less than 1?µg?kg?1), were used to determine the efficiency of the extraction method. Seeds stored under poor conditions were found to be contaminated with aflatoxins B1 and B2 as were the fractions. The sums of AFB1 and AFB2 in stored paddy rice, hulls, brown rice, bran and white rice were 141, 39, 158, 367 and 56?µg?kg?1, respectively. The ratio of aflatoxin B1 and B2 was about 10?:?1. AFG1 and AFG2 were less than 1?µg?kg?1. Thus, brown rice contained 92.9% of the aflatoxins in paddy rice, whereas white rice contained only 27.9%.  相似文献   

16.
Dried figs (4917 samples) destined for export from Turkey to the European Union were collected between September and December during the very dry crop year of 2007 and tested for aflatoxins B1, B2, G1 and G2 by immunoaffinity column clean-up and reverse-phase high-performance liquid chromatography (RP-HPLC). While 32% of the samples contained detectable levels of total aflatoxins, 9.8% of them exceeded the European Union limits. Aflatoxin levels were in the range of 0.2–259.46 µg kg?1 and 2.04–259.46 µg kg?1 for all samples and samples that exceeded the limits, respectively. A substantial increase in the incidence of aflatoxins was observed in 2007 compared with previous years, most likely due to the drought stress, high temperatures and low relative humidity encountered during the period from January to September of that year. In 2007, the mean temperature was 1–2°C higher, there was 300 mm less total rain, and the mean relative humidity was 10–15% lower than in 2002–06. The average concentration of individual aflatoxins present in the samples was quantified to determine whether the drought conditions promoted certain types of aflatoxins. Among the contaminated samples, aflatoxin B1 occurred in 97% of the contaminated samples, followed by G1 in 47%, B2 in 24%, and G2 in 6% of samples. Concentrations of individual aflatoxins exhibited great variability among the samples but were not significantly different from those reported in previous studies, which were conducted under conditions without drought and high temperatures.  相似文献   

17.
To determine differences in mean aflatoxin contamination and subsample variance from dry and slurry homogenizations, 10 kg of six different, naturally contaminated dried fig samples were collected from various exporting companies in accordance with the EU Commission Directive. The samples were first dry-mixed for 5 min using a blender and sub-sampled seven times; the remainder was slurry homogenized (1 : 1, v/v) and sub-sampled seven times. Aflatoxin B1 and total aflatoxin levels were recorded and coefficient of variations (CV) computed for all sub-samples. Only a small reduction in sub-sample variations, indicated by the lower CV values, and slight differences in mean aflatoxin B1 and total aflatoxin levels were observed when slurry homogenization was applied. Therefore, 7326 dried figs, destined for export from Turkey to the EU and collected during the 2008 crop year, were dry-homogenized and tested for aflatoxins (B1, B2, G1 and G2) by immunoaffinity column clean-up using RP-HPLC. While 34% of the samples contained detectable levels of total aflatoxins (0.20–208.75 µg kg?1), only 9% of them exceeded the EU limit of 4 µg kg?1 in the range 2.0–208.75 µg kg?1, respectively. A substantial increase in the incidence of aflatoxins was observed in 2008, most likely due to the drought stress experienced in Aydin province as occurred in 2007.  相似文献   

18.
A sensitive and reliable multi-mycotoxin method was developed for the simultaneous determination of 16 toxicological important mycotoxins, such as aflatoxins B1, B2, G1, and G2; enniatins A, A1, B, and B1; beauvericin; ochratoxin A; fumonisin B1, B2, and B3; diacetoxyscirprenol; HT-2; and T-2 toxin in dried fruits using liquid chromatography combined with electrospray ionization-triple quadrupole tandem-mass spectrometry. Mycotoxins have been extracted from the samples using a modified quick, easy, cheap, effective, rugged, and safe procedure. The method was based on a single extraction with acidified acetonitrile, followed by partitioning with salts, avoiding any further clean-up step. Limits of detections ranged from 0.08 to 15 μg kg?1 and limits of quantification ranged from 0.2 to 45 μg kg?1, which were below the legal limit set by the European Union for the legislated mycotoxines. The recoveries in spiked samples ranged from 60 to 135 % except for beauvericin using matrix-matched calibration curves for quantification, with good inter- and intraday repeatability (respective relative standard deviation ≤20 and 9 %). The developed method was applied to 15 commercial dried fruits: raisins, figs, apricots, plums, and dates purchased in local markets from Spain. Among the mycotoxins studied, enniantins and aflatoxins were the most predominant mycotoxins.  相似文献   

19.

ABSTRACT

The main focus of our study was to implement a rapid, inexpensive and reliable method that could be utilized to check the cereals for safety (i.e., screening for total aflatoxins, as well as individual B1, B2, G1, G2 aflatoxins and ochratoxin A). We developed a protocol by which we were able to isolate mycotoxins from cereals collected from different regions of Romania. After extraction in chloroform, the mycotoxins were separated by thin‐layer chromatography (TLC) and quantified using densitometry. Forty‐three samples of different cereals (wheat, maize, rye and Triticale) were analyzed. Twenty‐five of the 43 samples (58.14% of the total number) were found to be contaminated with different mycotoxins in various concentrations: aflatoxin B1 (1.6–5.7 µg/kg), aflatoxin B2 (0.89–4 µg/kg), aflatoxin G1 (1.2–5.76 µg/kg), aflatoxin G2 (0.96–3.4 µg/kg) and/or 4.3–30 µg/kg ochratoxin A. The concentration of total aflatoxin contamination ranged from 11.2 to 10.8 µg/kg. Among the different cereals, the highest number of contaminated samples was found to be in the wheat samples (62.5%). The method outlined in this study has been adopted already by our laboratory for current analyses of mycotoxins. The results obtained using this method is in compliance with the strict regulatory guidelines developed both in Romania, as well as in the European Union.

PRACTICAL APPLICATIONS

Thin‐layer chromatography (TLC) is a rapid, inexpensive and convenient method that can be used routinely to screen for mycotoxins. This article describes the detailed procedures for the extraction, purification and quantification of aflatoxins and ochratoxin A, using TLC. Using this method one can identify concomitantly five different mycotoxins and by coupling it with densitometry a quantitative determination is also possible. Therefore, this could become a routine technique in regional laboratories responsible for checking agrifood safety.  相似文献   

20.
A simple and rapid high performance liquid chromatographic with fluorescence detection method for the determination of the aflatoxin B1, B2, G1 and G2 in peanuts, rice and chilli was developed. The sample was extracted using acetonitrile:water (90:10, v/v%) and then purified by using ISOLUTE® multimode solid phase extraction. After the pre-column derivatisation, the analytes were separated within 3.7 min using Chromolith® performance RP-18e (100–4.6 mm) monolithic column. To assess the possible effects of endogenous components in the food items, matrix-matched calibration was used for the quantification and validation. The recoveries of aflatoxins that were spiked into food samples were 86.38–104.5% and RSDs were <4.4%. The method was applied to the determination of aflatoxins in peanut (9), rice (5) and chilli (10) samples. Liquid chromatography–tandem mass spectrometry analysis using triple quadruple analyser and operated in the multiple reaction monitoring modes on the contaminated samples was performed for confirmation.  相似文献   

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