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1.
The mycotoxin ochratoxin A (OTA) and its metabolite ochratoxin alpha (OTα) were determined in milk and blood from nine lactating women who provided samples soon after delivery at a hospital in southern Chile. The analytical method applied liquid–liquid extraction with chloroform, and in the case of blood, an extra purification with solid phase extraction prior to HPLC analysis with fluorescence detection. OTA was detected in all human milk samples, with an average concentration of 106?±?45 ng/L (range 44–184 ng/L). Levels of OTα were 40?±?30 ng/L (LOQ 40 ng/L), but increased considerably upon enzymatic hydrolysis with ß-glucuronidase/sulfatase (up to 840?±?256 ng/L) in human milk. By contrast, there was no evidence for conjugates of OTA. The data on OTA in breast milk and levels reported in blood from women in Chile are indicative of an efficient lactational transfer of the mycotoxin. Infant exposure to OTA was estimated by considering their daily OTA intake with human milk at early stages of nursing. For the majority of milk samples, the calculated OTA intake of infants exceeded the tolerable daily intake (TDI) of 5 ng/kg body weight (bw)/day proposed by the Nordic Expert Group, and infant exposure approached the provisional tolerable doses of 14–16 ng/kg bw/day suggested by the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) and by EFSA for adults. The present study documents and confirms the presence of OTA in human milk at levels where the TDI can be exceeded. These results point out the need to continue food and biological monitoring and to develop strategies, e.g. dietary recommendations to pregnant and lactating women, aimed to reduce OTA exposure in early periods of life.  相似文献   

2.
Cyclopiazonic acid (α-CPA) is a tremorgenic mycotoxin that is commonly produced by certain species of the aspergilli, in particular Aspergillus flavus, which is more widely known for production of the aflatoxins. Despite the fact that α-CPA may co-occur with aflatoxins, immunoassay-based methods for monitoring for CPA have not been widely developed. We report the development and evaluation of several monoclonal antibodies (mAbs) for α-CPA. Two mAbs in particular were very sensitive, with IC50s of 1.1 and 1 ng/mL (clones 1418 and 1231, respectively). Tolerances to aqueous methanol or acetonitrile were good, which permitted the development of an antigen-immobilized competitive enzyme-linked immunosorbent assay (CI-ELISA) for detection of CPA in maize. Spiked or naturally contaminated maize, extracted with aqueous methanol, was diluted with buffer for analysis. The working range for the assay (IC20 to IC80) was from 5 to 28 μg/kg. Recoveries from maize spiked over the range from 2 to 50 μg/kg averaged 88.6 ± 12.6%. Twenty-eight samples of maize were tested by both the CI-ELISA and a liquid chromatography-fluorescence (LC-FLD) method. For the five samples above the limits of quantitation of both methods, CI-ELISA tended to overestimate CPA content, a difference that we speculate may be due to related metabolites or perhaps “masked” derivatives of CPA. The antibodies developed and the resulting CI-ELISA will be useful tools for further evaluation of the prevalence of this mycotoxin in maize.  相似文献   

3.
Various cultivars of red chilli were collected from a small town named Kunri, located in the province Sindh, Pakistan. This town is a hub of red chilli production in Asia. A total of 69 samples belonging to 6 cultivars were obtained and analysed for the occurrence of aflatoxins and Aspergillus flavus, to explore the potential of resistant and susceptible germplasm. Aflatoxins were detected by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), while A. flavus was isolated and identified using agar plate, blotter paper, deep freezing and dilution techniques. Molecular characterization using internal transcribed spacer (ITS) 1/4 and A. flavus specific FL1-F/R primers confirmed the identity of A. flavus. The data revealed that 67 and 75% samples contaminated with aflatoxin B1 (AFB1) and with A. flavus, respectively. A highly susceptible chilli cultivar was ‘Nagina’, showing 78.8% frequency of total aflatoxins (1.2–600 μg/kg) and a mean of 87.7 μg/kg for AFB1 and 121.9 μg/kg for total aflatoxins. A. flavus was detected with 93% frequency and 2.14 × 104 colony forming units. In contrast, cultivars ‘Kunri’ and ‘Drooping Type’ were found to be resistant, with low levels of aflatoxins and fungal counts. The study was conducted for the first time to explore two potential cultivars that were less susceptible towards A. flavus and aflatoxin contamination. These cultivars could be preferably cultivated and thereby boost Pakistan’s chilli production.  相似文献   

4.
The aim of this study was to conduct a survey assessing (a) the ochratoxin A (OTA) content in different samples of Astragalus propinquus root (AR), one of the fundamental herbs in traditional Chinese medicine, and (b) the rate of OTA transfer to AR decoctions that are traditionally used to reduce general weakness and increase overall vitality. A validated method of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was used to determine OTA concentrations in AR samples and AR decoctions. The limit of quantification was 0.35 ng/g; the recovery of the HPLC method for AR samples was 82%; and the relative standard deviation (SD) of repeatability was 2.6%. All 40 tested AR samples were positive, with a mean value of 451.0 ng/g (range, 28.8–1700.0 ng/g). The transfer rate of OTA to decoctions, from a naturally contaminated and homogenized AR sample (internal reference material) with a concentration of OTA of 288.9 ng/g?±?12.3 (SD), was 83.4%?±?8.5 (SD). We believe it is necessary to continue OTA monitoring in AR and other herbal products, estimate the actual human usual intake, and perform health risk assessment.  相似文献   

5.
Aflatoxin contamination has been well known as a world-wide health-threatening problem in tropical countries including Indonesia. This research was undertaken to determine the degree of aflatoxin contamination in different Indonesian foodstuffs. A preliminary survey was carried out to evaluate the level of total aflatoxin (AfT) and aflatoxin B1 (AfB1) contamination of baby foods, peanut products, and corn products, which were purchased from traditional markets and supermarkets in Indonesia during the year 2001-2002. Eighty two peanut products, 12 baby foods products, and 11 corn products from different brands were analysed for AfT and AfB1 using the Enzyme-Linked Immunosorbent Assay (ELISA) method. The results indicate that, of the brands analysed, 35% of the peanut products were contaminated with aflatoxins at various levels (range 5 to 870 μg/kg). Peanut-chilli sauces had the highest percentage of AfT contamination 9/12 (75%), which was followed by traditional snacks 5/11 (45%), peanut butter 4/11 (40%), flour egg coated peanut 6/16 (37%), and peanut cake 3/10 (30%). Fried peanuts and roasted peanut were found to contain aflatoxin at relatively lower percentages of 9% and 8%, respectively. From the 12 analysed baby food samples, on the other hand, no sample was found to be contaminated with aflatoxins. Two of 11 samples (18%) of corn based products were contaminated with AfT, ranging between 5.8 and 12.4 μg/kg. Additionally, 30 selected samples in different concentration ranges were further analysed to verify the correlation between ELISA and HPLC techniques and results were compared.  相似文献   

6.
Forty samples of dried vine fruit (raisin, n?=?22; currant, n?=?18) were collected in 2009?C2011 from the Iranian market. Aflatoxins (AFs) and ochratoxin A (OTA) were determined in these samples after immunoaffinity column clean-up by high performance liquid chromatography (HPLC) with fluorescence detection. The limit of quantification (LOQ) for AFs B1. B2, G1, G2, and OTA were 0.62, 0.50, 0.70, 0.40, and 0.42?ng/g, respectively. AFB1 was found in one sample of raisin (0.64?ng/g) and in two samples of currant (0.20 and 0.63?ng/g). AFB2 (0.33?ng/g) and AFG2 (0.49?ng/g) were found in 2 samples of currant. OTA was detected in 3 of the 22 samples of raisin (mean 2.21?ng/g) and in one sample of currant (2.99?ng/g). The results show that in AFs and OTA levels are well below the regulatory limits both of the European Union and of Iran.  相似文献   

7.
Two kinds of monoclonal antibodies (MoAbs), OCA-10A and OCA-1B, were prepared based on their specificity to ochratoxin A (OTA) and ochratoxin B (OTB) and on their tolerance to 40% methanol. In an indirect competitive enzyme-linked immunosorbent assay, the half maximal inhibitory concentration (IC(50)) value of OCA-10A was 27ng/mL for OTA and 17ng/mL for OTB, and that of OCA-1B was 28ng/mL for OTA and 13ng/mL for OTB. Immuno-affinity columns (IACs) using these MoAbs were prepared with agarose gel beads. The IAC with OCA-1B showed a NaCl-dependent binding ability to OTA and OTB, while interestingly, the IAC with OCA-10A bound to them without NaCl. The IAC with OCA-10A showed a high methanol tolerance when compared with existing IACs, as expected from the high methanol tolerance of OCA-10A itself. Such tolerance was maintained for the application of the cocoa extract with 70% methanol and the wheat extract with 60% acetonitrile, while the tolerance was slightly altered by interference from the cocoa extract. Examinations with organic solvents at higher concentrations than the allowable level in existing IACs showed that OTA and OTB spiked with wheat, cocoa and red wine could be purified with high recovery. The newly developed IAC is expected to show sufficient clean-up ability for food analyses.  相似文献   

8.
The effects of several natural antioxidants (copaiba oil, buriti oil, cocoa butter, tucuman butter, oregano and white thyme) were assessed in the enzymatic synthesis of monoglycerides (MAG) from the glycerolysis of babassu oil. The reactions were catalyzed by Burkholderia cepacia lipase immobilized on SiO2–PVA and the assays carried out in batch and continuous runs. Results were compared with those attained in the control reactions (without any strategy to avoid oxidation), and the best approach was tested in a continuous packed-bed reactor. The best performance was obtained using N2 in the reaction medium (60 % of MAG) followed by buriti oil (57.6 % of MAG) and cocoa butter (56.6 % of MAG), preventing the oxidation of babassu oil in batch reaction. However, the incorporation of buriti oil in the medium influenced the MAG profile, leading to the largest formation of monoolein, unlike other runs. Similar results were obtained in continuous reactions, using inert atmosphere and cocoa butter (24–25 % of MAG). Thereby, among the tested antioxidant agents, cocoa butter was the most effective in both systems, because it did not interfere in the MAG profile and also reduced the cost of the process.  相似文献   

9.
The accuracy and precision of a commercially available system based on an indirect competitive immunoassay and planar waveguide technology was evaluated for the analysis of deoxynivalenol (DON), ochratoxin A (OTA), zearalenone (ZEAR), and T-2 toxin in wheat. The system generally performed well at the tested concentrations that were close to the regulatory limits of DON and OTA in wheat. The mean percent recovery of OTA from certified and in-house reference materials ranged from 90 to 111 %, with a relative standard deviation of 8–16 % (at 4.2, 4.9, and 7.0 μg/kg). Mean percent recoveries of DON ranged from 75 to 103 %, with a relative standard deviation of 14–20 % (at 610, 940, and 1300 μg/kg). As analyte concentrations approached the lower limits of the working range of 3 μg/kg OTA and 400 μg/kg DON, the mean percent recoveries and relative standard deviation increased for both DON and OTA. A lack of reference materials precluded a thorough evaluation of the method for the analysis of ZEAR and T-2. The particular strength of the technology was that multiple mycotoxins were analyzed simultaneously.  相似文献   

10.
The effect of processing steps as well preservatives used in French bread making namely propionic acid and/or potassium sorbate (0.2%) on the destruction of aflatoxins B1 and G1 was studied. Mixing and baking processes showed marked destruction of aflatoxins B1 and G1; being 71.2% and 52.5% for aflatoxin B1 after mixing and baking steps, while reaching 73.9% and 54.5% for aflatoxin G1. Fermentation step caused additional 15.3% and 15.0% destruction of aflatoxins B1 and G1. On the other hand, aflatoxin B1 destruction was 79.2% and 50.7% when propionic acid was used and 75.3 and 56.7% in the presence of potassium sorbate and after mixing and baking steps respectively. Concerning aflatoxins G1 it was found that mixing and baking steps showed destruction of 81.9% and 53.4% in the presence of propionic acid and 75.1 and 49.4% in the presence of potassium sorbate in this respective order. Generally, it can be concluded that using propionic acid as preservative appeared to be more effective on the destruction of aflatoxins B1 and G1 than potassium sorbate in French bread making.  相似文献   

11.
Brewer’s yeasts are rich in vitamins of the B-group and contain other nutritive factors; therefore, they are recommended as valuable food supplements for people with special dietary requirements like pregnant women, children, and adolescents, or for people with high physical activity. Additionally, certain strains of brewer’s yeast are known to be capable of adsorbing xenobiotics such as mycotoxins. Because of that, these yeasts are regarded as having positive effects in food, beverage, and feed technology. Their potential to bind mycotoxins such as ochratoxin A (OTA), however, can subsequently lead to a contamination of such brewer’s yeasts used as food supplements. In the present study, we analyzed 46 samples of brewer’s yeasts for the occurrence of OTA by HPLC with fluorescence detector (HPLC-FLD) and for confirmatory measurements by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Nearly 90 % of the samples were contaminated with OTA, the levels ranging from the limit of detection (LOD, 0.01 μg/kg) to 4.2 μg/kg. The mean and median levels of contamination were 0.49 and 0.27 μg/kg, respectively. Based on these results, the additional weekly OTA exposure by regularly consuming such supplements was assessed. Depending on different subpopulations (adults, children) and levels of contamination used for calculation, the additional OTA intake via brewer’s yeast products ranged from 9.3 % (mean case) to 114 % (worst case) of the published mean weekly OTA intake in Germany (adults 279.3 ng, children 195.3 ng). At present, maximum levels for OTA in nutritional supplements like brewer’s yeast do not exist. Based on our results, however, it is recommended that producers of these dietary supplements should include mycotoxin analyses in ongoing and future self-monitoring programs and in product quality checks.  相似文献   

12.
The aim of this study was to compare ochratoxin A (OTA) levels in pig tissues and biological fluids after animal exposure to contaminated diet (250 μg OTA/kg of feed) during 4 weeks of fattening. OTA concentrations were quantified using a validated immunoassay method (ELISA) and high-performance liquid chromatography with fluorescence detector (HPLC-FD). The highest mean OTA concentration in pig tissues was determined in kidneys of exposed animals (13.87?±?1.41 μg/kg), followed by lungs (10.47?±?1.97 μg/kg), liver (7.28?±?1.75 μg/kg), spleen (4.81?±?0.99 μg/kg), muscle tissue (4.72?±?0.86 μg/kg), fat tissue (4.11?±?0.88 μg/kg), heart (3.71?±?1.09 μg/kg), and brain (3.01?±?0.25 μg/kg). Furthermore, on the last day of exposure (day 28), significantly higher mean OTA levels were determined in urine (16.06?±?3.09 μg/L) in comparison to serum (4.77?±?1.57 μg/L) showing that OTA urine analysis could be a good marker to identify elevated levels of this contaminant in porcine tissues used for human consumption. This study gave guidelines for the most efficient OTA control in pig-derived biological materials that can be exercised at slaughterhouses.  相似文献   

13.
Citrinin (CIT) and Ochratoxin A (OTA) are nephrotoxic mycotoxins which can co-occur in food commodities, resulting in internal exposure. Studies in many countries reported on the presence of OTA in human blood; however, such biomonitoring data for CIT is still scarce. This study was conducted to characterize both CIT and OTA biomarker levels in plasma of volunteers since food analysis data are insufficient to assess human exposure in Bangladesh. In total 104 blood samples were collected from university students in 2013 (sampling 1: n?=?64, midsummer) and 2014 (sampling 2: n?=?40, end winter) for analysis of CIT and OTA and their metabolites HO-CIT and OTα by LC-MS/MS and HPLC-FD techniques, respectively. CIT and HO-CIT were detected in 90% (max 2.70 ng/mL) and 85% (max 1.44 ng/mL) of all samples. Mean levels in sampling 2 (CIT 0.47 ng/mL; HO-CIT 0.40 ng/mL) were higher than in sampling 1 (0.25 ng/mL; 0.37 ng/mL) indicative of variable CIT exposure. OTA was present in all (max 6.63 ng/mL) and OTα in 98% (max 0.99 ng/mL) of the samples. In sampling 1, mean OTA (0.85 ng/mL) was higher than in sampling 2 (0.51 ng/mL); the reverse situation was found for OTα mean levels. The calculated dietary OTA intake among the students (mean 9.9; max 91.7 ng/kg bw/week) was lower than the tolerable weekly intake for this mycotoxin (120 ng/kg bw/week) set by EFSA. But frequent co-exposure to CIT should be considered, and the results of this study indicate the necessity to identify major sources of CIT and OTA intake in the Bangladeshi population.  相似文献   

14.
A survey of aflatoxins in sesame in Iran   总被引:1,自引:0,他引:1  
A study of the occurrence of aflatoxins (AF) in sesame seeds was conducted in the Khorasan province of Iran between September 2009 and August 2010. Samples (n = 182) were analyzed by liquid chromatography (LC), and detection limits for AFB1, AFB2, AFG1 and AFG2, were 0.45, 0.19, 0.61, and 0.22 ng/g, respectively. AFB1 was detected in 33 samples (18.1%), at a mean level of 1.62 ± 1.32 ng/g, and a maximum level of 5.54 ng/g. AFB1 levels exceeded the European Union (EU) maximum tolerated level (MTL, 2 ng/g) in 9 samples, and the Iran MTL (5 ng/g) in 1 sample. Regarding total aflatoxins (AFT), the mean level was 0.92 ± 1.36 ng/g, and the maximum level was 5.54 ng/g. No sesame sample exceeded the Iran MTL (15 ng/g), but two samples exceeded the EU MTL (4 ng/g) for AFT. It is concluded that low levels of AFs occur frequently in sesame from Iran.  相似文献   

15.
Humans are constantly exposed to mycotoxins (e.g. aflatoxins, ochratoxins), mainly via food intake of plant and animal origin. The health risks stemming from mycotoxins may result from their toxicity, in particular their carcinogenicity. In order to prevent these risks, the International Agency for Research on Cancer (IARC) in Lyon (France)—through its IARC Monographs programme—has performed the carcinogenic hazard assessment of some mycotoxins in humans, on the basis of epidemiological data, studies of cancer in experimental animals and mechanistic studies. The present article summarizes the carcinogenic hazard assessments of those mycotoxins, especially aflatoxins (aflatoxin B1, B2, G1, G2 and M1), fumonisins (fumonisin B1 and B2) and ochratoxin A (OTA). New information regarding the genotoxicity of OTA (formation of OTA-DNA adducts), the role of OTA in oxidative stress and the identification of epigenetic factors involved in OTA carcinogenesis–should they indeed provide strong evidence that OTA carcinogenicity is mediated by a mechanism that also operates in humans–could lead to the reclassification of OTA.  相似文献   

16.
In 2004–2005, samples of several selected Polish foods such as cereal products, nuts, dried fruits, coffee and culinary spices collected from Warsaw market and taken from food producers were analyzed on presence of aflatoxin B1, B2, G1, G2 (AF), ochratoxin A (OTA), zearalenone (ZEA) and deoxynivalenol (DON). After extraction and clean-up of extracts on immunoaffinity columns (IAC), mycotoxin analyses were carried out by HPLC using fluorescence and UV detectors. The concentrations of aflatoxins and ochratoxin A depending on the kind of sample ranged from 0.02 to 7.8 (one sample, of peanuts) and 0.02–11.9 μg/kg (one coffee sample), respectively. The levels of ZEA and DON were found to be below 50 °g/kg.  相似文献   

17.
18.
M. Jalili  S. Jinap  S. Radu 《Mycopathologia》2010,170(4):251-258
The concentration of ochratoxin A (OTA) in 120 commercial pepper (84 pre-packed and 36 bulk samples), which consist of local and imported white and black pepper in powder and seed form in Malaysia were determined. The objective of the study was to investigate and compare OTA concentration in black pepper and white pepper being commercialized in Malaysia. Determination method was based on HPLC with fluorescence detection coupled with immunoaffinity column clean-up step. Mobile phase consisted of acetonitrile–water–acetic acid (49.5:49.5:1.0, v/v/v), and flow rate was 1 ml/min. The LOD was 0.02 ng/g, and the average recovery values of OTA ranged from 79.5 to 92.0% in black pepper and 81.2–90.3% in white pepper. A total of 57 samples (47.5%) were contaminated with OTA ranging from 0.15 to 13.58 ng/g. The results showed that there was a significant difference between type of pepper and brands. OTA concentration in black pepper was significantly higher than white pepper (p < 0.05). The highest concentration of ochratoxin, 13.58 ng/g, was detected in a sample of black pepper seed followed by 12.64 ng/g in a sample of black pepper powder, both were bulk samples purchased from open market.  相似文献   

19.
The purpose of this study was to determine the distribution of aflatoxins in rice milling fractions and to estimate dietary intakes. A total of 413 rice samples (paddy 58, parboiled 69, brown 84, white 93, and broken 109) were analyzed by HPLC with fluorescence detector. The results showed that 64?% paddy (16.35?±?1.67???g/kg), 38?% parboiled (14.20?±?2.04???g/kg), 33?% brown (9.85?±?1.25???g/kg), 42?% white (7.10?±?1.39???g/kg), and 50?% broken (8.5?±?1.71???g/kg) rice samples were contaminated with aflatoxins. It was found that paddy rice was most contaminated with aflatoxins while white rice was least contaminated. The percentage of samples exceeding EU maximum contents for total aflatoxins in rice (4???g/kg) varied from 14 to 36?% when compared to the analyzed rice fractions. The total estimated amount of aflatoxin intake for average rice consumers ranged from 19.1 to 26.6?ng/kg body weight/day, much higher than the reference value of 1?ng/kg body weight/day. This is the first report discovering that rice is a major contributor to the dietary intake of aflatoxins in Pakistan.  相似文献   

20.
Ochratoxin A (OTA) and citrinin (CIT) are both nephrotoxic and teratogenic in animals, and the occurrence of these mycotoxins in food may cause adverse health effects in humans. Data on the combined exposure to these food contaminants are still scarce, especially in pregnancy. Therefore, a biomonitoring study was conducted to determine the presence of urinary biomarkers of exposure to OTA and CIT in pregnant women in Bangladesh. In total, 54 spot urine samples were collected from residents of a rural and a suburban area of the Savar region in Dhaka district for analysis of OTA and CIT urinary biomarkers by previously validated HPLC-FD and LC-MS/MS methods. Most urines were positive for OTA and CIT biomarkers, with OTA being detected in 93 % (range 0.01–0.84 ng/mL) and CIT biomarkers in 87 % (range 0.02–6.93 ng/mL) of all samples. The mean levels of OTA were different between the rural (0.06?±?0.07 ng/mL) and suburban (0.15?±?0.19 ng/mL) study participants. CIT and its metabolite dihydrocitrinone (HO-CIT) were more than twofold higher in the rural (0.42?±?1.20 and 0.55?±?1.04 ng/mL, respectively) than the suburban (CIT 0.15?±?0.13 ng/mL; HO-CIT 0.23?±?0.18 ng/mL) participants. When a provisional daily intake for CIT was calculated, it exceeded the preliminary tolerable value set by European Food Safety Authority (0.2 μg/kg/day) in 9 % of the rural participants but in none of the urban participants. Urinary biomarker levels for OTA and CIT did not show significant association with intake of certain types of food consumed by the pregnant women, although total CIT biomarker levels were considerably higher among participants who consumed more rice in a day. Overall, this study indicates a frequent co-exposure to OTA and CIT among pregnant women in Bangladesh, at levels similar to those determined recently in the general population of this country.  相似文献   

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