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1.
The widespread occurrence of F. moniliforme and the toxic effects of its secondary metabolites, the fumonisins B1(FB1), B2(FB2) and B3(FB3), make it imperative that fumonisin contamination of maize, a major constituent of animal feed as well as the staple diet of many populations, be closely monitored to reduce the risk of fumonisin exposure. Equine leukoencephalomalacia and porcine pulmonary oedema have been associated with the intake of feed heavily contaminated with fumonisins. In addition, high levels of fumonisins in the maize-based staple diets of certain populations have been linked to a high incidence of oesophageal cancer in the Transkei region of South Africa and in Linxian and Cixian Counties, China. Bulk shipments of maize imported into South Africa from the USA and Argentina during 1992 were sampled at the port of entry to determine fumonisin levels. Of the 79 samples from two US shipments, all were positive for fumonisins, with FB1 constituting approximately 71% of the total fumonisins with an overall mean of 2.35 micrograms/gFB1. The maximum FB1 level observed was 3.9 micrograms/g. These levels contrast with those obtained from two Argentinian bulk shipments, which also were all positive for fumonisins, but had a mean FB1 level of 0.31 microgram/g and a maximum observed level of 0.7 microgram/g FB1 measured over 47 composite samples.  相似文献   

2.
Fumonisin B1 (FB1) and fumonisin B2 (FB2) are mycotoxins mainly produced by Fusarium verticillioides and Fusarium proliferatum, which are field pathogens of maize. A survey was conducted on the incidences of FB1 and FB2 in both maize and derived products purchased in Portugal. The analytical method involved extraction with methanol-water, clean-up by immunoaffinity column and derivatization with naphthalene-2,3-dicarboxaldehyde. Determination was carried out by high-performance liquid chromatography (HPLC) with spectrofluorimetric detection, with liquid chromatography/mass spectrometry (LC/MS) confirmation. The presence of FB1 and FB2 was determined in 67 samples of maize and maize-based foods, such as flour, semolina, starch, sweet maize, cornflakes and other breakfast cereals, and snacks collected in 2005. FBs were found in 15 samples at concentrations ranging from 113 to 2026 µg kg-1. Two of the samples showed higher contamination levels than the limits established by the European Commission Regulation. None of the samples contained levels of fumonisins that would lead to an exposure exceeding the tolerable daily intake (TDI).  相似文献   

3.
In Argentina, wheat is the most consumed cereal by the human population. Since fumonisins occurence in wheat grains and wheat-based products have been reported worldwide, a survey was conducted in order to determine fumonisin contamination in 91 wheat-based products (white wheat flour samples, wheat flour used at bakery products and whole-wheat flour samples) collected from different retail stores of Rio Cuarto city in Argentina using HPLC-MS/MS. Sixty-seven samples (74%) showed contamination by fumonisins. From these samples, 16 showed fumonisin levels between LOD and LOQ (between 0.01 to 0.05 ng/g), while fumonisins (FB1 + FB2) in quantifiable samples ranged from 0.05 ng/g to 18.9 ng/g. Although FB1 was more prevalent, FB2 was foun3d in higher levels than FB1. Overall, fumonisin prevalence was high, but concentrations were far below EU or USA limits set for maize and maize-based products.  相似文献   

4.
Sixty samples of corn from both conventional and organic farms were tested for internal fungal contamination. Molds were identified to genus, and those belonging to the genus Fusarium were identified to species. Twenty isolates of Fusarium verticillioides were tested with a high-performance liquid chromatography-naphthalene dicarboxaldehyde-fluorescence method for their ability to produce fumonisins B1 and B2. The internal fungal infection in organic maize (63.20%) was significantly higher than that in conventional maize (40.27%) (P < 0.05). However, the distribution of fungal genera indicated a significantly higher prevalence of Fusarium in conventional (34.93%) than in organic (18.15%) maize, making Fusarium the predominant fungus in conventional maize. This difference in mold distribution between organic and conventional maize was attributed to the difference in cultivation system. The dominant Fusarium species in both conventional and organic samples was F. verticillioides. There were no significant differences in the ability of 20 selected isolates of F. verticillioides to produce fumonisins on conventional or organic corn. Up to 13.3% of the conventional corn samples contained fumonisins B1 and B2 at mean concentrations of 43 and 22 ng/g, respectively. Organic corn samples had somewhat lower levels of contamination: 35 ng/g fumonisin B1 and 19 ng/g fumonisin B2 (P > 0.05). The organic farming system, with well-balanced crop rotation, tillage, and compost fertilization, produced corn that was less likely to be contaminated with Fusarium species, although no significant difference in fumonisin concentrations was found between the two types of contaminated corn.  相似文献   

5.
In order to optimize the analytical method for the determination of fumonisin B1 (FB1) and fumonisin B2 (FB2) in diVerent maize products, five materials (maize flour, cornflakes, extruded maize, muffins and infant formula) were investigated under a variety of experimental conditions organized in a ruggedness test according to a factorial design. The influence of five factors (extraction solvent, extraction mode, volume of extraction solvent, test sample size and clean-up) on method performances was tested by four laboratories using spiked materials (0.5 μg/g and 1.5 μg/g FB1 + FB2) and naturally contaminated materials (ca 1.5 μg/g with FB1 + FB2). The end determination step was performed by high-performance liquid chromatography analysis of the o-phthaldialdehyde derivatized extracts. The ruggedness test permitted identification of two critical factors in the analysis of fumonisins in the above products, namely 'extraction solvent' and 'cleanup procedure'. In particular, the use of acetonitrile (ACN)-water (1 + 1, v + v) as extraction solvent and immunoaffinity column for clean-up provided better recovery of fumonisins and chromatographic resolution as compared with methanol (MeOH)-water (3 + 1, v + v) and strong anion exchange (SAX), respectively. However, phase separation occurring after extraction with ACN-water may have given incorrect results. Based on the information obtained with the present study it was possible to develop a new method horizonhorizontally applicable to all the above mentioned maize-based food matrices.  相似文献   

6.
Fifteen maize samples from four markets and processing sites in Accra, Ghana were analysed for fumonisins B1, B2, and B3. All samples contained fumonisins. Total fumonisin levels for 14 samples ranged from 70 to 4222 microg kg(-1). One sample of visibly mouldy kernels contained 52 670 microg kg(-1) total fumonisins. Mycological examination of the samples showed Aspergillus spp. as the most dominant fungi (76.4%) followed by Penicillium spp. (19.9%). Fusarium formed 2.6% with Fusarium verticillioides as the predominant Fusarium species. Thirty-two Fusarium strains representing five species isolated from the maize samples were tested for the production of fumonisins in maize substrates. From 95% (21 of 22) of the F. verticillioides strains tested, all three types of fumonisins were produced. Total fumonisin levels ranged from 127 to 11 052 microg g(-1). Additional studies on maize samples from 15 processing sites in Accra revealed a co-occurrence of both fumonisins and aflatoxins in 53% (8 of 15) of the samples.  相似文献   

7.
In the Centane magisterial area of South Africa, high rates of oesophageal cancer have been associated with home-grown maize contaminated with fumonisins. The aim of this study was to implement a simple intervention method to reduce fumonisin exposure in a subsistence-farming community. The hand-sorting and washing procedures, based on traditional maize-based food preparation practices, were previously customised under laboratory-controlled conditions. Home-grown maize and maize-based porridge collected at baseline were analysed for fumonisin B1, B2 and B3. The geometric mean (95% confidence interval) of fumonisin contamination in the home-grown maize at baseline was 1.67 (1.21–2.32) mg kg?1 and 1.24 (0.75–2.04) mg kg ?1 (dry weight) in the porridge. Fumonisin exposure was based on individual stiff porridge consumption and the specific fumonisin levels in the porridge (dry weight) consumed. Porridge (dry weight) consumption at baseline was 0.34 kg day?1 and fumonisin exposure was 6.73 (3.90–11.6) µg kg?1 body weight day?1. Female participants (n = 22) were trained to recognise and remove visibly infected/damaged kernels and to wash the remaining maize kernels. The discarded kernels represented 3.9% by weight and the fumonisins varied from 17.1 to 76.9 mg kg?1. The customised hand-sorting and washing procedures reduced fumonisin contamination in the maize and porridge by 84 and 65%, respectively. The intervention reduced fumonisin exposure by 62% to 2.55 (1.94–3.35) µg kg?1 body weight day?1. This simple intervention method has the potential to improve food safety and health in subsistence-farming communities consuming fumonisin-contaminated maize as their staple diet.  相似文献   

8.
伏马茵素分布广泛且毒性较大,丢弃受伏马菌素污染的玉米将造成巨大的经济损失,因此降解和去除玉米及其制品中伏马菌素的技术和方法日益受到人们的重视.介绍了伏马菌素的性质以及伏马菌素污染食品的情况,对去除伏马菌素的方法,如物理法、化学法、生物法进行总结和阐述,并对去除和降解伏马菌素的前景进行展望.  相似文献   

9.
This study determined maize-user practices that influence the presence of fumonisin and aflatoxin contamination of maize in food consumed in the rural areas of Tanzania. Samples of the 2005 maize harvest in Tanzania were collected from 120 households and examined for fumonisins and aflatoxins. Information on whether the maize was sorted to remove defective (visibly damaged or mouldy) maize before storage and whether the damaged and mouldy maize or the non-dehulled maize was used as food was also collected. In addition, the percentage of defective kernels in the samples was determined. Ninety per cent of the households sorted out defective maize, 45% consumed the defective maize and 30% consumed non-dehulled maize. In 52% of the samples fumonisins were determined at levels up to 11,048 µg kg?1 (median = 363 µg kg?1) and in 15% exceeded 1000 µg kg?1; the maximum tolerable limit (MTL) for fumonisins in maize for human consumption in other countries. Aflatoxins were detected in 18% of the samples at levels up to 158 µg kg?1 (median = 24 µg kg?1). Twelve per cent of the samples exceeded the Tanzanian limit for total aflatoxins (10 µg kg?1). Aflatoxins co-occurred with fumonisins in 10% of the samples. The percentage defective kernels (mean = 22%) correlated positively (r = 0.39) with the fumonisin levels. Tanzanians are at a risk of exposure to fumonisins and aflatoxins in maize. There is a need for further research on fumonisin and aflatoxin exposure in Tanzania to develop appropriate control strategies.  相似文献   

10.
Fumonisins B (FBs) can occur in maize as free forms and as hidden FBs (interaction between FBs and matrix macro-constituents). The analytical methods to detect free FBs in maize and derived products usually involve extraction with aqueous methanol and/or acetonitrile; for hidden FBs, alkaline hydrolysis (2 M KOH) and following CH3CN extraction is used. Recently, we proposed a simple phosphate buffer (PB) extraction to detect free FBs in masa and maize samples. This study aimed at evaluating if this method is suitable to detect also hidden FBs; then, a comparison between the most common solvents, PB, and alkaline hydrolysis was carried out. For maize samples, the results showed that 0.4 M PB can extract both free and most hidden FBs; however, this method was not suitable for some categories of maize-based processed food products, in particular cornflakes, chips, and crispbreads. To solve this drawback, a modified PB extraction, which entails the addition of Carrez solutions in order to precipitate proteins, was tested and satisfactory results were obtained. Finally, the alkaline hydrolysis of maize-based food extracts showed that bound FBs can be co-extracted together with free forms by 0.4 M PB and quantified as hydrolyzed FBs.  相似文献   

11.
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   

12.
A survey was conducted to determine the occurrence of fumonisin B1, B2 and B3 during 2007 in 186 samples of organic and conventional locally available corn products. Samples included baby food (n = 62), corn flour (11), cornflakes (23), pasta (14), cookies (17) and other corn products (59) were obtained from popular markets of Valencia (Spain) and Perugia (Italy). The analytical method used pressurized liquid extraction and liquid chromatography/electrospray ionization tandem mass spectrometry with a triple quadrupole (QqQ) analyser. Of the 104 Spanish samples, 22% contained levels in the range of 2–449 µg kg?1, 2–229 µg kg?1 and 6–105 µg kg?1 for FB1, FB2 and FB3, respectively, while 19 (23%) of the 82 Italian samples were positive with quantifiable levels between 2–235 µg kg?1, 3–187 µg kg?1, and 4–40 µg kg?1 for fumonisins B1, B2 and B3, respectively. Overall, none of the Italian samples and only one organic baby food sample from a Spanish market was above the maximum permitted levels established by European legislation. Fumonisins were found mostly in corn flour followed by cookies and cornflakes. Eleven samples from Spain and nine samples from Italy were organic products, being contaminated the 72% and 77% of the samples, respectively. Analysis of the results showed that levels of fumonisins in corn products were similar in Italy and Spain. The safety of fumonisin intake through corn products was demonstrated by the calculation of the estimated daily intake of both populations considering organic and conventional products separately, which ranged from 1.7 × 10?3 to 0.72 µg kg?1 bw day?1 and comparing them with the provisional maximum total daily intake (PMTDI) of 2 µg kg?1 bw day?1 established by the European Union.  相似文献   

13.
The fate of aflatoxins and fumonisins, two mycotoxins that cooccur in maize, was studied through the traditional processing of naturally contaminated maize in mawe, makume, ogi, akassa, and owo, maize-based foods common in Benin, West Africa. Levels of total aflatoxin and fumonisin were measured at the main unit operations of processing, and the unit operations that induce significant reduction of mycotoxin level were identified. Overall reduction of mycotoxin level was more significant during the preparation of makume (93% reduction of aflatoxins, 87% reduction of fumonisins) and akassa (92% reduction of aflatoxins, 50% reduction of fumonisins) than that of owo (40% reduction of aflatoxins, 48% reduction of fumonisins). Sorting, winnowing, washing, crushing combined with dehulling of maize grains were the unit operations that appeared very effective in achieving significant mycotoxin removal. Aflatoxins and fumonisins were significantly recovered in discarded mouldy and damaged grains and in washing water. Fermentation and cooking showed little effect. During the preparation of ogi and akassa, reduction of fumonisin levels measured in food matrix was lower (50%) compared to mawe and makume, probably due to significant fumonisin release in ogi supernatant. Consequently, the use of ogi supernatant for preparing beverages or traditional herbal medicines could be harmful as it is likely to be contaminated with mycotoxin from the raw maize.  相似文献   

14.
To determine whether pozol, a nixtamalized maize-based food was contaminated with aflatoxins, samples of non-fermented pozol were collected during the period November 2002 to April 2003 from local markets at Comitan in Chiapas, Mexico. The samples were analyzed for the presence of aflatoxins. Nineteen out of one hundred and eleven samples were contaminated with aflatoxin B2 (AFB2) and traces of aflatoxin B1 (AFB1). The percentage of samples contaminated with AFB2 in pozol prepared with white maize was 5.4%. Pozol mixed with toasted cacao paste had a contamination rate of 41.5%. No aflatoxins were detected in pozol prepared with yellow maize. It was found that only 1 of 19 contaminated samples had aflatoxin concentrations above 20 ppb.  相似文献   

15.
To evaluate the effectiveness of maize detoxification achieved with a modified tortilla-making process (MTMP), maize contaminated with aflatoxin B(1) (AFB(1)) and aflatoxin B(2) (AFB(2)) at levels of 22.46, 69.62, and 141.48 ng/g (AFB(1)+ AFB(2)) was processed into tortillas. Aflatoxin content was determined according to the 991.31 AOAC official method. Based on the results obtained with spiked samples (0.78 to 25 ng/g), the mean recovery was 92%, with a standard error of 1.2, and a coefficient variation value of 4.4%. The MTMP caused 68, 80, and an 84% decrease in aflatoxin content, respectively. Extract acidification (as occurs during digestion) prior to mycotoxin quantification caused some reformation of the aflatoxin structure in tortillas (up to 3%). According to these results, the MTMP seems to be safe for decontamination since a low percentage of the initial aflatoxin concentration can be reverted to the original fluorescent form upon acidification. PRACTICAL APPLICATION: The potential presence of aflatoxins in maize destined for human consumption is a serious problem to the Mexican food supply, as these toxic compounds may persist during the traditional alkaline-process for tortilla elaboration. Consequently, new detoxification procedures are needed that eliminate or at least minimize the aflatoxin risk, through lowering aflatoxin concentration in maize-based products. Under these considerations, the use of MTMP is recommended, since it has definite advantages including non-production of wastewater and reduced energy/time consumption.  相似文献   

16.
Occurrence of aflatoxins and fumonisins in Incaparina from Guatemala.   总被引:2,自引:0,他引:2  
The occurrence of aflatoxins and fumonisins in Incaparina was investigated. Incaparina is a mixture of corn and cottonseed flour with added vitamins, minerals and a preservative. It has been marketed as a high-protein food supplement, particularly for children on protein-deficient diets. According to estimates, 80% of Guatemalan children in their first year are given Incaparina to provide an adequate diet. Eight samples of Incaparina manufactured in Guatemala were collected. Five were from three different geographical locations in the USA and three were from Guatemala. Seven were examined for fungal contamination and analysed for aflatoxins and fumonisins. Aspergillus flavus was the predominant fungus in all samples purchased in the USA and in one sample purchased from Guatemala, whereas Fusarium verticillioides was present in only two samples (one from the USA and one from Guatemala). All samples contained aflatoxins, ranging from 3 to 214 ng g(-1) and <2 to 32ng g(-1) for aflatoxin B(1) and aflatoxin B(2), respectively; and one sample contained aflatoxin G(1) (7 ng g(-1)). Total aflatoxins present ranged from 3 to 244 ng g(1). All samples contained fumonisins, ranging from 0.2 to 1.7 microg g(-1), <0.1 to 0.6 microg g(-1), and <0.1 to 0.2 microg g(-1) for fumonisins B(1), fumonisin B(2), and fumonisin B(2), respectively. Total fumonisins present ranged from 0.2 to 2.2 microg g(-1). The identity of aflatoxin B(2) was confirmed using both the chemical derivatization method and liquid chromatographic (LC)/mass spectrometric (MS) analysis. Appropriate regulatory action was recommended for the import of Incaparina and has been in effect since 22 December 1998.  相似文献   

17.
Food-grade corn and corn-based food products intended for human consumption were analyzed for the incidence and levels of fumonisin B1 (FB1), fumonisin B2 (FB2), moniliformin, and Fusarium molds. A total of 100 food-grade commercial corn samples were obtained from two corn processing companies at five different locations in the United States. Seventy-one percent of the samples contained FB1 with concentrations ranging from 43 to 1,642 microg/kg. None of the samples contained FB2. Fifty percent of the samples contained moniliformin with concentrations ranging from 26 to 774 microg/kg. All samples were infected by Fusarium molds, and the infection rates ranged from 8 to 88%. Thirty-four samples of corn-based food products were purchased from supermarkets in Arizona, California, Nebraska, and Ohio. Sixty-five percent of the samples contained FB1, ranging in concentrations from 28 to 2,679 microg/kg. FB2 was detected in 29% of the samples with concentrations ranging from 30 to 797 microg/kg. Sixty-eight percent of the samples contained moniliformin with concentrations ranging from 31 to 858 microg/kg. Sixty-two percent of the samples contained viable Fusarium mold propagules ranging from 9.5 x 10(1) to 5.5 x 10(5)/g. The simultaneous occurrence of FB1 and moniliformin was observed in 34% of corn samples and 53% of corn-based food products. This study has shown co-occurrence of fumonisins and moniliformin in food-grade corn and corn-based foods that indicates a risk of simultaneous exposure of consumers to both toxins.  相似文献   

18.
A liquid chromatography-high-resolution mass spectrometry-based method is reported for the quantification of 20 selected mycotoxins and the simultaneous screening for 200 fungal metabolites in food. For regulated mycotoxins, such as aflatoxins, fumonisins, ochratoxin A, zearalenone and trichothecenes, the evaluation of the method performance characteristics, such as precision, trueness, limit of detection and matrix effects, has been exemplified for the matrix maize. In the case of the limit of detection, an alternative evaluation approach for high-resolution FT-Orbitrap data is proposed. Measurements of the signal-to-noise ratios obtained from 'full-profile mode' data led to detection limits between 8 and 160?ng?g(-1). Eight naturally contaminated wheat- and maize-based matrix test materials, originating from interlaboratory comparison studies, were used to confirm the trueness of the method for deoxynivalenol, zearalenone, fumonisin B(1) and B(2), HT-2, and T-2 toxin. In addition to accurate quantification of the most relevant mycotoxins, the full-scan chromatograms were used to investigate the potential of the FT-Orbitrap to screen simultaneously for a large number of fungal metabolites. First, a list of 200 metabolites, potentially being present in food samples, was established. Next, specific detection and identification criteria were defined, which are based on accurate mass, peak intensity and isotopologue ratio. The application of these criteria to the suspected metabolites from the list resulted in the putative identification of 13 fungal metabolites in addition to the target toxins.  相似文献   

19.
Fumonisins B1 and B2 in black tea and medicinal plants   总被引:4,自引:0,他引:4  
Fumonisins are mycotoxins produced by Fusarium moniliforme that are prevalent in cereals and other agricultural products. These mycotoxins have been pointed to as a natural cause of equine leukoencephalomalacia, porcine pulmonary edema, and human esophageal cancer. A total of 87 samples, 18 black tea samples and 69 samples of four different medicinal plants (chamomile, leaves of the orange tree, leaves and flowers of the linden tree, and corn silk), for infusions preparations were acquired from supermarkets in Lisbon, Portugal. The samples were analyzed for the incidence and levels of fumonisin B1 (FB1) and fumonisin B2 (FB2) by high-performance liquid chromatography. The detection limit was 20 microg/kg for both FB1 and FB2. FB1 was detected in 55 (65.5%) of the 87 samples. The highest number of positive samples was found in black tea (88.8%). with levels ranging from 80 to 280 microg/kg. Relative to the medicinal plants, the leaves of the orange tree had higher concentrations of FB1 (range, 350 to 700 microg/kg) followed by leaves and flowers of the linden tree (range, 20 to 200 microg/kg). The samples of corn silk and chamomile had less contamination of FB1, with concentrations ranging from 50 to 150 microg/kg and 20 to 70 microg/kg, respectively. None of the samples tested had contamination of FB2. This is the first report of the natural occurrence of fumonisins in black tea and medicinal plants in Portugal. We reinforce the necessity to implement risk management measures for safety control of this kind of product.  相似文献   

20.
伏马菌素是一种重要的真菌毒素,主要存在于受镰孢菌污染的玉米及其制品中。伏马菌素能够引起人畜多种疾病,严重危害人畜的健康。为了减少伏马菌素对人畜健康的危害,采用挤压膨化法、氢氧化钙浸泡湿磨法降低玉米及其制品中的伏马菌素。结果表明,在不添加葡萄糖的情况下,挤压膨化能够降低玉米中40.42%~44.52%的伏马菌素,而添加葡萄糖(2.5%、5.0%和7.5%)的情况下,降解率则能达到71.82%~90.16%。氢氧化钙浸泡湿磨能明显降低玉米中伏马菌素的含量,并且随浸泡时间(8~24h)的延长,去除率逐渐升高,在0.03mol/L的氢氧化钙浸泡24h的条件下,湿磨玉米能够去除80.71%的伏马菌素。  相似文献   

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