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1.
Dried figs for export from Turkey from crop years 2003 through 2006 were tested for aflatoxin B1 and total aflatoxins. For export to the European Union, consignments of 0.5 to 10 tonnes of dried figs were sampled according to European Commission regulations, and high-pressure liquid chromatography (HPLC) was used to determine concentrations of aflatoxins Bl, B2, G1, and G2. For each consignment of dried figs, a 30-kg sample (comprising 100 subsamples) was divided into three 10-kg subsamples, which were separately blended and analyzed with HPLC. This monitoring effort was conducted for figs from 2003, 2004, 2005, and up to June 2006, for a total of 10,396 30-kg samples (28,489 analyses). The incidence of contamination with aflatoxin B1 at higher than 2 ng/g was on average 0.6, 2.0, 4.0, and 2.4% for 2003, 2004, 2005, and up to June 2006, respectively, whereas contamination with total aflatoxins at higher than 4 ng/g was 2.6, 3.0, 5.1, and 2.7%. There was significant variability in contamination between replicate 1-kg samples, indicating small numbers of individual contaminated figs were probably responsible. There were also substantial differences in the relative proportions of aflatoxins B1, B2, G1, and G2 among samples, suggesting different contributing fungal sources.  相似文献   

2.
Mycoflora, the mycotoxigenic properties of moulds, and natural contamination with mycotoxins such as aflatoxins (AFs), cyclopiazonic acid (CPA), fumonisin B(1) (FB(1)) and ochratoxin A (OTA) were investigated in dried figs. Dry fig samples were collected from orchards during the drying stage in the Aegean Region of Turkey. Fungal isolates were identified using morphological, chemical as well as molecular methods. Mycotoxigenic characteristics of moulds were assessed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Mycotoxins except CPA (by TLC) were determined by HPLC. All the fig samples were contaminated with moulds and 94.7% contained one or more mycotoxigenic species. The most prevalent moulds present in dried figs belong to the Aspergillus section Nigri members, being 93.9% positive for the samples, followed by Fusarium spp., Aspergillus section Flavi and Penicillium spp. On the other hand, Fusarium spp. had the highest count and the number of fumonisin producing Fusarium was also high. A total of 48% of 115 dried fig samples contained OTA (range = 0.1-15.3 ng g(-1)), 74.7% of the samples had FB(1) (range = 0.05-3.65 mg kg(-1)), 10.0% of the samples had aflatoxin (range = 0.1-763.2 ng g(-1)) and 24.3% of the samples were tentatively identified as being contaminated with CPA (range = 25-187 ng g(-1)). Dried fig samples were contaminated with one (33.0%), two (47.0%), three (5.2%) and four mycotoxins (3.5%). A total of 11.3% of dried fig samples were not contaminated with any of the four mycotoxins. To the best of our knowledge, CPA and fumonisin have been found for the first time in dried figs.  相似文献   

3.
Survey of aflatoxin contamination of dried figs grown in Turkey in 1986   总被引:2,自引:0,他引:2  
A total of 284 dried fig samples, collected from fields during drying, and from warehouse and processing units in the Aegean region of Turkey in 1986, were examined for aflatoxin contamination. Aflatoxin B1, B2, and G1 were detected in 4, 2, and 2% of the samples, respectively, which were of the lower grade of figs taken from the drying stage. The average alfatoxin levels in positive samples were estimated to be 112.3 (B1), 50.6 (B2), and 61.4 ng/g (G1). The samples collected from storage (64 samples) and processing units (14 samples) contained no aflatoxins. The results of this survey show that aflatoxin contamination of Turkish dried figs in 1986 was highly correlated with the poorer grade of fig.  相似文献   

4.
A total of 117 dried fruit samples (black sultanas, white sultanas, dates, dried plums, dried figs and apricots) from different origins were analysed both for toxigenic fungi and for the presence of ochratoxin A. Amongst the fungi found, Aspergillus niger was predominant, with 406 isolates, of which 15% were ochratoxin A producers. They were followed by A. ochraceus, with 15 isolates and 87% ochratoxigenics, and A. carbonarius, with only five isolates of which 60% were ochratoxin A producers. The average infection rates for A. niger in black sultanas, plums, figs, dates and white sultanas were 22.0, 8.0, 4.0, 1.5 and 0.5%, respectively. The apricot samples were not contaminated by any fungi or ochratoxin A. Black sultana and dried figs contained the highest contamination with ochratoxin A, with 33 and 26.3% of the samples containing more than 5 µg kg-1 respectively, while all the white sultanas, dates and plums had no sample that exceeded this limit.  相似文献   

5.
Approximately 200 samples of rice (including white, brown, red, black, basmati and jasmine, as well as wild rice) from several different countries, including the United States, Canada, Pakistan, India and Thailand, were analysed for aflatoxins, ochratoxin A (OTA) and fumonisins by separate liquid chromatographic methods in two different years. The mean concentrations for aflatoxin B(1) (AFB(1)) were 0.19 and 0.17 ng g(-1) with respective positive incidences of 56% and 43% (≥ the limit of detection (LOD) of 0.002 ng g(-1)). Twenty-three samples analysed in the second year also contained aflatoxin B(2) (AFB(2)) at levels ≥LOD of 0.002 ng g(-1). The five most contaminated samples in each year contained 1.44-7.14 ng AFB(1) g(-1) (year 1) and 1.45-3.48 ng AFB(1) g(-1) (year 2); they were mostly basmati rice from India and Pakistan and black and red rice from Thailand. The average concentrations of ochratoxin A (OTA) were 0.05 and 0.005 ng g(-1) in year 1 and year 2, respectively; incidences of samples containing ≥LOD of 0.05 ng g(-1) were 43% and 1%, respectively, in the 2 years. All positive OTA results were confirmed by LC-MS/MS. For fumonisins, concentrations of fumonisin B(1) (FB(1)) averaged 4.5 ng g(-1) in 15 positive samples (≥0.7 ng g(-1)) from year 1 (n = 99); fumonisin B(2) (FB(2)) and fumonisin B(3) (FB(3)) were also present (≥1 ng g(-1)). In the second year there was only one positive sample (14 ng g(-1) FB(1)) out of 100 analysed. All positive FB(1) results were confirmed by LC-MS/MS.  相似文献   

6.
BACKGROUND: Detection and quantification of ochratoxin A (OTA) in dried fig samples purchased in Spain has been carried out using high‐performance liquid chromatography with fluorescence detection after extraction with methanol and sodium bicarbonate, and clean‐up by using an immunoaffinity column. RESULTS: The detection limit of the method was 0.06 ng g?1, and the limit of quantification 0.18 ng g?1. OTA was detected in 31 (88.6%) out of 35 samples of dried figs analysed, with concentrations that ranged from < 0.1 to 277 ng g?1. However, only three samples contained OTA concentrations above the tolerable level set by European Commission regulations for dried vine fruits (10 ng g?1). CONCLUSION: The results of this survey show the value of monitoring OTA in dried figs especially if they are home grown. Copyright © 2011 Society of Chemical Industry  相似文献   

7.
Mycoflora, the mycotoxigenic properties of moulds, and natural contamination with mycotoxins such as aflatoxins (AFs), cyclopiazonic acid (CPA), fumonisin B1 (FB1) and ochratoxin A (OTA) were investigated in dried figs. Dry fig samples were collected from orchards during the drying stage in the Aegean Region of Turkey. Fungal isolates were identified using morphological, chemical as well as molecular methods. Mycotoxigenic characteristics of moulds were assessed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Mycotoxins except CPA (by TLC) were determined by HPLC. All the fig samples were contaminated with moulds and 94.7% contained one or more mycotoxigenic species. The most prevalent moulds present in dried figs belong to the Aspergillus section Nigri members, being 93.9% positive for the samples, followed by Fusarium spp., Aspergillus section Flavi and Penicillium spp. On the other hand, Fusarium spp. had the highest count and the number of fumonisin producing Fusarium was also high. A total of 48% of 115 dried fig samples contained OTA (range?=?0.1–15.3?ng?g?1), 74.7% of the samples had FB1 (range?=?0.05–3.65?mg?kg?1), 10.0% of the samples had aflatoxin (range?=?0.1–763.2?ng?g?1) and 24.3% of the samples were tentatively identified as being contaminated with CPA (range?=?25–187?ng?g?1). Dried fig samples were contaminated with one (33.0%), two (47.0%), three (5.2%) and four mycotoxins (3.5%). A total of 11.3% of dried fig samples were not contaminated with any of the four mycotoxins. To the best of our knowledge, CPA and fumonisin have been found for the first time in dried figs.  相似文献   

8.
In the spring and autumn of 1994, a total diet study, in which 123 participants collected duplicates of their 24-hour diets, was carried out. The goal of this study was to determine the mass fractions of a number of analytes in these duplicate diets, so as to be able to establish oral daily intake values. After measurements were carried out for pesticides, PCBs, elements, sterols, nitrate and nitrite, and fatty acids, the duplicate diet study was concluded with analyses for aflatoxin M1, aflatoxin B1 and ochratoxin A. For this purpose a method of analysis was developed, that could simultaneously determine these mycotoxins at very low levels. The method involved chloroform extraction, liquid-liquid extraction, immunoaffinity cleanup and liquid chromatography. The method was supplemented with a procedure to confirm the identity of chromatographic peaks, assumed to represent aflatoxin M1, aflatoxin B1 and ochratoxin A. The method was in-house validated. Recoveries ranged from 68-74% for aflatoxin M1 (at spiking levels from 30-120 ng/kg, c.v. 7.6%), from 95-97% for aflatoxin B1 (at spiking levels from 50-200 ng/kg, c.v. 2.8%), and from 75-84% for ochratoxin A (at spiking levels from 150-600 ng/kg, c.v. 4.3%). Limits of quantitation (defined as signal/noise = 10) were estimated to be 24, 5 and 16 ng/kg lyophilised material for aflatoxin M1, aflatoxin B1 and ochratoxin A respectively. The newly developed method was used to analyse 123 samples of 24-hour diets. Aflatoxin M1 was detectable in 48% of the samples; the toxin contents remained below the limit of quantitation in all samples. Aflatoxin B1 could be detected in 42% of the samples; in 25% of the samples the levels were above the limit of quantitation. Ochratoxin A could be quantified in all samples. The analytical results were further processed to estimate levels of intake. Intake levels for the aflatoxins were very low, and could not reliably be established. The mean ochratoxin A intake was estimated to be 1.2 ng/kg body weight per day. This is well below the tolerable daily intake established by JECFA at 14 ng/kg body weight per day. The current dietary intake of ochratoxin A in the Netherlands is concluded to pose no appreciable health risk.  相似文献   

9.
Dried figs are sensitive commodities to aflatoxin contamination. Although preventive methods are the logical solution to aflatoxin problems, once the product is contaminated, decontamination procedures are inevitable. In this study, the effectiveness of a procedure consisted of acidification/alkalization, and heat treatment in degradation of aflatoxins was evaluated. The pH of dried fig extracts was adjusted to 3.1, 3.5, 6, 8 or 10 by adding acid or base. Extracts were heated at 50, 75 or 98C for 1 or 2 h, and then the residual aflatoxin B1, B2, G1 and G2 were determined. The highest level of degradation for aflatoxin B1 (97  ±  1%) and B2 (87  ±  1%) were observed at pH 10 in samples heated at 98 and 50C, respectively. Some treatments resulted in 100% degradation of aflatoxin G1 and G2 so that they could not be detected.

PRACTICAL APPLICATIONS


Aflatoxin contamination is a serious problem for a number of processed and non-processed foods, including dried figs. This not only presents severe risks to human and animal health but also causes economic problems for countries such as Turkey, U.S.A., Greece and Spain, which produce and export dried figs. It is clear that detoxifying studies are unavoidable when the amount of crop contaminated by toxins is considered. Therefore, the food industry is in search of applications that are effective in mycotoxin detoxification and adaptable to food processes. This is the first report on degradation of aflatoxins in naturally contaminated dried figs by such a promising method.  相似文献   

10.
We conducted a survey of aflatoxin B1, B2, G1, and G2, ochratoxin A, and fumonisin B1, B2, and B3 contamination in various foods on the retail market in Japan in 2004 and 2005. The mycotoxins were analyzed by high-performance liquid chromatography, liquid chromatography-mass spectrometry, or high-performance thin-layer chromatography. Aflatoxins were detected in 10 of 21 peanut butter samples; the highest concentration of aflatoxin B1 was 2.59 microg/kg. Aflatoxin contamination was not found in corn products, corn, peanuts, buckwheat flour, dried buckwheat noodles, rice, or sesame oil. Ochratoxin A was detected in oatmeal, wheat flour, rye, buckwheat flour, green coffee beans, roasted coffee beans, raisins, beer, and wine but not in rice or corn products. Ochratoxin A concentrations in contaminated samples were below 0.8 microg/kg. Fumonisins were detected in popcorn, frozen corn, corn flakes, and corn grits. The highest concentrations of fumonisins B1, B2, and B3 in these samples were 354.0, 94.0, and 64.0 microg/kg, respectively.  相似文献   

11.
High levels of ochratoxin A in licorice and derived products   总被引:1,自引:0,他引:1  
The ochratoxin A (OTA) content of 30 samples of licorice root and derived products (licorice-confectionery, licorice block, and licorice extract) was analyzed by a standard HPLC-fluorescence technique and confirmed by methyl-ester formation. All analyzed samples of licorice and derived products were found to contain ochratoxin A, and some of them showed extremely high concentrations up to 252.8 ng/g of OTA. Highest levels of ochratoxin A were found in dry licorice root, averaging 63.6 ng/g, while mean contents in fresh licorice root were 9.2 ng/g. Licorice-confectionery (sweets) contained 3.8 ng/g of OTA. Ochratoxin A was also abundant in two licorice derivatives, liquid licorice extract (16.0 ng/g) and solid licorice block (39.5 ng/g). The ochratoxin levels found in licorice and derived products are higher than those reported in the literature for other food commodities. The experiments of OTA transfer into the tea beverages showed that almost 5% of the OTA present in dry licorice root is transferred to the corresponding decoction tea, whereas only 1% of OTA remains in infusion tea. The significance of the levels of ochratoxin A in licorice and its derivatives is discussed in the context of existing data on ochratoxin contamination in foods.  相似文献   

12.
Sun drying of seedless grapes (Vitis vinifera cv. Sultanina) is widely practised in the western Aegean Region providing Turkey with a significant share in the world trade of sultanas. Research was initiated in 1998 to determine the incidence of ochratoxin A (OTA), to identify the major factors resulting in contamination and to develop techniques to reduce or prevent contamination. This paper assesses OTA formation in five experimental vineyards located in Manisa province of Turkey between 1998 and 2003. The cultural practices recorded were tillage (type and timing), fertilisation, plant protection, irrigation, trellising, pruning, GA(3) application, harvest maturity and date, and drying practices (type of drying yard, dipping into alkaline solution, length of drying period). In the experimental vineyards, no OTA was found at veraison. OTA levels in grapes harvested at fresh maturity ranged between 相似文献   

13.
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   

14.
This survey examined 30 samples of rice (n = 10), maize (n = 10) and peanuts (n = 10) from C?te d'Ivoire for aflatoxin B1, fumonisin B1 and zearalenone using immunoassays, and ochratoxin A using a validated HPLC method with fluorescence detection. In C?te d'Ivoire, as in other countries, several mycotoxins are present in the same commodities. These mycotoxins are from different structural families: aflatoxin B1, fumonisin B1, zearalenone and ochratoxin A, normally produced by fungal species from Aspergillus, Penicillium and Fusarium genera. Some samples contained four mycotoxins (86%). Four peanuts samples did not show ochratoxin A (14%), whereas they contained aflatoxin B1 concentrations above the EU regulatory limits. Concentrations of ochratoxin A, zearalenone and fumonisin B1 were low and may not cause problems per se; however, fears remain that the tolerable daily intake may be exceeded due to eating habits and synergistic effects could be important with the combination of several mycotoxins. Investigations in this direction are underway, together with isolation and characterization of the fungal species involved.  相似文献   

15.
From 1998 to 2001, 216 ingredients intended for incorporation into chicken feed, which included groundnut cake, maize, millets, rice bran, sorghum, soybean, sunflower, and mixed feeds, were assayed for aflatoxins and ochratoxin A contamination using an indirect competitive enzyme-linked immunosorbent assay. Thirty-eight percent of the samples were contaminated with aflatoxins and 6% with ochratoxin A. The incidence scores of aflatoxin contamination in excess of 10 microg/kg were 41 of 95 for maize, 18 of 30 for mixed feeds, 10 of 37 for groundnut, 6 of 29 for sorghum, 5 of 10 for sunflower, 3 of 14 for rice bran, and 1 of 8 for millet. Ochratoxin A contamination, in excess of 10 microg/kg, was found in 9 of 29 sorghum samples, 1 of 27 groundnut samples, 1 of 14 rice bran samples, 1 of 10 sunflower samples, and 2 of 8 millet samples. Ochratoxin A was not found in maize and mixed feeds. None of the three soybean samples contained ochratoxin A. This is the first report, to our knowledge, of co-occurrence of aflatoxins and ochratoxin A in Indian poultry feeds. The results confirm the importance of analysis of ingredients before incorporating them into mixed feeds.  相似文献   

16.
The mold flora of 50 dried fig samples consumed in Turkey was examined and the aflatoxigenic ones were determined. Among 127 fungi isolated, 74 were Aspergillus, 24 were Trichoderma, 16 were Fusarium and 13 were Acremonium. Of the isolates, 17 were aflatoxigenic and four of them were capable to produce aflatoxin, three of which were characterized as A. flavus and one as A. parasiticus. Aflatoxin production of four strains was confirmed by high pressure liquid chromotography. The effect of UV irradiation on mold count and aflatoxin quantity was also tested. It was found that UV irradiation led to a decrease in the mold count and aflatoxin quantity.

PRACTICAL APPLICATIONS


Studies have shown that the concentration of aflatoxins may exceed the determined limits in dried figs. Its presence can be a potential threat to the health of consumers. Dried figs are one of the major agricultural export products of Turkey ( Senyuva et al. 2005 ). The effects of UV irradiation on mold flora of dried figs and aflatoxins have been examined. The Aspergillus flavus and parasiticus agar (AFPA) medium is used for detection of aflatoxigenic species, and coconut agar medium (CAM) is used to detect the aflatoxin-producing ability of aflatoxigenic strains. It was found that the reproduction of the molds in dried figs, consequently the aflatoxigenic mold strains, can be depressed by UV irradiation. It was found that increasing time of UV irradiation led to a decrease in the mold count in dried figs. In addition, a UV irradiation applied for 90 min, was found to decrease the aflatoxin quantity in dried figs in an amount of 25%. Because of inexpensiveness and easiness of the application it was concluded that the UV irradiation can be used as a practical application.  相似文献   

17.
The presence of ochratoxin A in foods and wines is of current interest owing to its toxic effects. Ochratoxin A is a widely distributed mycotoxin with nephrotoxic activity. It constitutes a new restrictive agent for the export of vinicultural products and is thus important from an economic as well as a scientific point of view. In this study the determination of ochratoxin A in Greek wines was made by means of commercial immunoaffinity columns for purification followed by HPLC with fluorescence detection for quantification of the toxin. The method was applied to 28 dry wines (14 red, 13 white, one rosé) and seven sweet wines (three red, four white) obtained by various viticultural and oenological practices. The levels of ochratoxin A ranged from <0.02 to 3.2 ng ml?1, with sweet wines containing higher levels than dry wines. Most of the wines contained relatively low concentrations of ochratoxin A (0.02–0.5 ng ml?1), which do not represent a serious risk to consumer health. © 2003 Society of Chemical Industry  相似文献   

18.
Aflatoxin B1-contaminated fruits were sorted out from 250 kg dried figs (five Turkish and three Greek batches) by bright-greenish-yellow fluorescence under UV light. The aflatoxins of the fluorescent figs were extracted by simple soaking in methanol. Aflatoxin B1 was determined by thin-layer chromatography. Parallel to this, an extraction for the determination of aflatoxin B1 was developed by a competitive ELISA and the two methods were compared with each other. In a highly contaminated batch of Turkish figs, statistically there was one fig among 350 which had a high aflatoxin content (greater than 100 ng/g fig) and one fig amongst 140 fruits with an aflatoxin B1 content of greater than 10 ng B1/g fig.  相似文献   

19.
Past surveys indicated that the occurrence of aflatoxins, zearalenone and ochratoxin A was not a problem in corn and corn products in the state of São Paulo, Brazil. However, according to recent studies, a change in pattern has been detected. To obtain a better overview, these toxins were searched for in 110 samples of freshly harvested corn, corresponding to 48 commercial cultivars planted at three different locations in the state. Aflatoxin contamination was found in 60 (54.5%) of the samples, in levels ranging from 6 to 1600 µg kg?1 aflatoxin B1. Insect control was exercised, so this was not the main route of corn infection. Endosperm type, germplasm type, number of days to flowering, and length of time the mature corn remained in the field had no effect on aflatoxin contamination. Ochratoxin A was found in two samples (206 and 128 µg kg?1) and zearalenone in one sample (4640 µg kg?1). Possible causes of the increase in aflatoxin levels may lie in the changing nature of the commercial cultivars employed, associated with the forsaking of the original landraces, and in a change in the toxigenicity pattern of the corn mycoflora Aspergillus flavus/Aspergillus parasiticus prevailing strains. © 2001 Society of Chemical Industry  相似文献   

20.
This survey examined 140 samples of raw maize as received at ports or at major maize mills in the UK and 12 after initial cleaning. Samples were examined for aflatoxins B1, B2, G1 and G2, ochratoxin A, zearalenone and fumonisins B1, B2 and B3 using fully validated analytical HPL C methods with detection limits of 0.1 mu g/kg for each aflatoxin and ochratoxin A, 4 mu g/ kg for zearalenone and 10 mu g/kg for each fumonisin. 95.0% and 92.1% of samples met the new EC statutory maximum permissible level for total aflatoxins and aflatoxin B1 respectively. The maximum concentration of ochratoxin A found was 1.5 mu g/kg. Zearalenone and fumonisins were detected in almost every sample with 41.7% of maize containing more than 100 mu g/kg of zearalenone and 48% of samples containing more than 1000 mu g/kg total fumonisins. Initial cleaning of raw maize reduced aflatoxin concentrations by about 40% and total fumonisins by 32%.  相似文献   

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