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1.
A comparison study of different extraction and clean-up procedures for the liquid chromatographic analysis of fumonisins B1 (FB1) and B2 (FB2) in corn masa flour was performed. The procedures included extraction (heat or room temperature) with acidic conditions or EDTA-containing solvents, and clean-up by immunoaffinity or C18 solid-phase extraction columns. Thereafter an analytical method was optimised using extraction with an acidic mixture of methanol–acetonitrile–citrate/phosphate buffer, clean-up through the immunoaffinity column and determination of fumonisins by liquid chromatography with automated pre-column derivatisation with o-phthaldialdehyde reagent. Recovery experiments performed on yellow, white and blue masa flours at spiking levels of 400, 800 and 1200?µg?kg?1 FB1 and of 100, 200 and 300?µg?kg?1 FB2 gave overall mean recoveries of 99% (±6%) for FB1 and 88% (±6%) for FB2. Good recoveries (higher than 90% for both FB1 and FB2) were also obtained with corn tortilla chips. The limits of quantification of the method (signal-to-noise ratio of 10) were 25?µg?kg?1 for FB1 and 17?µg?kg?1 for FB2. The method was tested on different commercial corn masa flours as well as on white and yellow corn tortilla chips, showing fumonisin contamination levels (FB1?+?FB2) up to 1800?µg?kg?1 (FB1?+?FB2) in masa flour and 960?µg?kg?1 in tortilla chips. Over 30% of masa flours originating from Mexico exceeded the European Union maximum permitted level.  相似文献   

2.
Ethyl carbamate (EC) is a naturally occurring toxic contaminant that may imply a risk to human health and is usually found in alcoholic beverages such as Chinese rice wine. An automated procedure for the rapid determination of EC in Chinese rice wine was developed by headspace solid‐phase microextraction (HS‐SPME) coupled to gas chromatography–mass spectrometry (GC‐MS). Using propyl carbamate as internal standard, the optimized HS‐SPME sampling with a polyacrylic fibre was 45 min at 70°C after applying 38.8% NaCl to saturate the sample. This method showed good linearity over a range of 25–600 µg L?1 (R2 = 0.997). The recovery, relative standard deviation and limit of detection were 90.21–97.35%, lower than 2.89% and 1.19 µg L?1, respectively. Additionally, the ethanol concentration had no effect on the analysis of EC. The total analysis time of 57 min per sample in continuous determination was twice as fast as the widely used solid‐phase extraction–GC‐MS method. This solvent‐free HS‐SPME‐GC‐MS procedure is suitable for the rapid, automated, and therefore convenient, determination of EC in Chinese rice wine. Copyright © 2012 The Institute of Brewing & Distilling  相似文献   

3.
Aspergillus niger has been recently found to produce fumonisin B2 (FB2). Thirty-one strains belonging to four Aspergillus species isolated from grape were evaluated for FB2 production on agar plates. Four out of eight strains of A. niger produced FB2 (29–293 µg g?1). None of the strains of A. uvarum (n = 7), A. tubingensis (8) and A. carbonarius (8) produced detectable amounts of toxin. The capability to produce FB2 was also confirmed by some A. niger strains artificially inoculated on grape berries. Natural occurrence of FB2, at levels of 0.01 and 0.4 µg ml?1, was found in two samples of must collected in Apulian cellars in 2007. This is the first report of FB2 contamination in must. These findings suggest that there is a potential risk of exposure to FB2 in the grape–wine chain for consumers and that A. niger may represent the major fumonisin-producing species among black Aspergilli occurring on grapes.  相似文献   

4.
Fusarium is the agent causing endosepsis (internal rot) in fig fruits and it is widespread in fig orchards in the Aegean region. This research was conducted to determine the natural occurrence of fumonisin B1 (FB1) and B2 (FB2) on dried fig fruits of Sarilop (syn. Calimyrna) variety which are mainly grown in the Big and Small Meander Basins in the Aegean region, representing 60% of world dried fig production. A total of 262 samples belonging to two quality classes, Class A and Class cull, were collected from 12 different locations during the two crop years in 2004 and 2005. The fumonisin detection method is based on extraction with methanol–acetonitrile–water, derivatization with o-phthaldehyde and quantification by reversed-phase high-performance liquid chromatography with fluorescence detection. The mean concentrations of FB1 and FB2 in fumonisin-positive samples were 0.080?±?0.047?µg?g?1 and 0.055?±?0.031?µg?g?1 and ranged from LOD to 0.332?µg?g?1 and from LOD to 0.198?µg?g?1, respectively. The incidence of fumonisins significantly differed between the two crop years. This difference can be attributed to the alteration in the rainfall regime from mid-May to mid-August (7.2?mm in 2004, 90.9?mm in 2005) and number of humid wind currents from a westerly direction (183 in 2004, 492 in 2005) from the end of July and mid-August that may have triggered a higher incidence of Fusarium spp. and thus fumonisin production.  相似文献   

5.
The potential risk of exposure to fumonisin B2 (FB2) in the grape-wine chain has recently been revealed after a report of Aspergillus niger in grapes and its ability to produce FB2 and FB4. The occurrence of these two fumonisins in wine was investigated by LC/MS/MS in 51 market samples (45 red, five white and one rosé wine) produced in various Italian regions. Nine samples of red wine were found to be contaminated by fumonisin B2 at levels ranging from 0.4 to 2.4 ng/ml, while FB4 was not detected in any of the tested samples. This is the first report on the natural occurrence of FB2 in wine, indicating that, although at low levels, there is a potential risk of FB2 exposure for the wine-consumer.  相似文献   

6.
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   

7.
Fumonisin B1 (FB1) and fumonisin B2 (FB2) are the most abundant fumonisins (FBs) occurring worldwide in maize, infected mainly by Fusarium verticillioides and F. proliferatum. A total of 307 corn kernel samples were collected from 45 districts of Gansu, Shandong, Ningxia and the Inner Mongolia provinces of the north and northwest China. The samples were analysed for FB1 and FB2 by high-performance liquid chromatography. The FBs (FB1+ FB2) incidence rate in samples from Gansu, Shandong, Ningxia and Inner Mongolia were 31.5%, 81.1%, 46.2% and 53.6%, respectively. Average FBs concentration was 703 μg/kg and the concentrations ranged from ≤11 to 13,110 μg kg?1. Results were compared with the European Commission (EC) regulation for FB1+ FB2 in unprocessed maize for human consumption of 4 mg kg?1. Contamination in 17 samples was higher than these levels. More than 80% of the samples from Liaocheng county, which is located in the Shandong province, were contaminated with FBs, with a mean total FB concentration of 2496 μg/kg. The result was significantly different from that of the Inner Mongolia (1399 μg/kg), Ningxia (373 μg/kg) and Gansu (175 μg/kg). Average exposure to FBs (0.12 μg/kg body weight/day) is within the provisional maximum tolerable daily intake of 2.0 mg/kg of body weight set by the Joint Food and Agriculture Organization and World Health Organization Expert Committee on Food Additives.  相似文献   

8.
The aim of this study was to detect and quantify fumonisin B1 (FB1) in cereal mixtures marketed in Brazil. Fifteen samples from different lots were acquired each month by internet from supermarkets during seven months, adding up to 105 analysed samples. The unit sample constituted of an original package with a minimum of 250 g. Extraction and clean-up of samples for FB1 determination were carried out using immunoaffinity columns. Identification and quantification of FB1 were performed by high performance liquid chromatography. Eighty-eight (83.8%) samples were contaminated with FB1 and four (3.8%) presented levels above 500 µg kg?1 (634, 703, 1269 and 1876 µg kg?1). Maximum FB1 + FB2 levels allowed by Brazilian regulations will reach 1500 µg kg?1 for corn flour in 2016 and 1000 µg kg?1 for others corn products. This study showed that even at levels below the legislative limits, human exposure to this toxin can occur constantly.  相似文献   

9.
Alcohol acetyltransferase (AATase), which is mainly encoded by ATF1, is one of the most important enzymes for acetate ester synthesis. On the other hand, isoamyl acetate is degraded into a higher alcohol under the catalysis of IAH1‐encoded esterase. In this study, Chinese Saccharomyces cerevisiae was used as the parent strain to construct an ATF1 overexpression and IAH1 disruption mutant. The results show that after 5 days of pre‐fermentation, the concentrations of ethyl acetate, isoamyl acetate and isobutyl acetate in the yellow rice wines fermented with EY1 (pUC‐PIAK) increased to 468.94 mg L?1 (which is approximately 22‐fold higher than that of the parent cell RY1), 99.86 and 7.69 mg L?1 respectively. Meanwhile, isoamyl alcohol production was reduced to 56.37 mg L?1 (which is approximately 50% of that produced by the parent strain RY1). Therefore, ATF1 overexpression and IAH1 disruption can significantly increase acetate esters contents and reduce isoamyl alcohol content in Chinese yellow rice wine, thereby paving the way for breeding an excellent yeast strain for high‐quality Chinese yellow rice wine production.  相似文献   

10.
Antibody preparation is the most important step in immunoassays. According to immunity theory (IT) “Antibody tends to recognize the furthest distance of side groups in the coupling league,”; immunogen must be well designed for high-specific antibody production for high-specific antibody preparation. In this research, a novel fumonisin B1 immunogen was synthesized in which protein was conjugated at C2 position to expose the distant two type–feature groups of side chains at C14 and C15 position. After immunization, a high-specific anti-FB1 monoclonal antibody (mAb) was produced with negligible CR value to analogues, including the most structure-related FB2 and FB3. Based on this mAb, a specific ELISA method was developed and validated for FB1 detection in rice with limit of detection at 0.0339 ng kg?1. In real-life samples, 20% were detected positive in 10 samples, with FB1 concentrations at 84 and 20 ng kg?1, respectively.  相似文献   

11.
Fumonisins are a group of structurally related mycotoxins produced mainly in maize by Fusarium verticillioides and F. proliferatum. The most abundant naturally occurring analogue is fumonisin B1 (FB1), with lesser amounts of fumonisin B2 (FB2) and fumonisin B3 (FB3) occurring. The C-series fumonisins (FCs) are structurally analogous to the B-series but lack the C-1 methyl group. Good and mouldy subsistence-grown maize samples were collected from the Centane and Bizana districts in the former Transkei region of South Africa. After extraction with methanol/water and clean-up on strong anion exchange solid phase extraction cartridges, FB1, FB2, FB3, FC1, FC3 and FC4 were determined by reversed-phase LC–MS/MS using positive ion electrospray ionisation. FB1 levels in both good and mouldy maize from Centane (means (±SD) 2.75?±?2.24 and 23.4?±?12.5?mg?kg?1, respectively) were higher than the corresponding levels in maize samples from Bizana (means 0.056?±?0.157 and 3.71?±?5.01?mg?kg?1, respectively). Similarly, FC1 levels in both good and mouldy maize from Centane (means 0.107?±?0.099 and 0.814?±?0.391?mg?kg?1, respectively) were higher than in Bizana, where FC1 was detected in only one (0.018?mg?kg?1) of 19 good maize samples and occurred in mouldy maize with a mean of 0.102?±?0.135?mg?kg?1. A significant correlation (r?=?0.982, p?<?0.01) was observed between FB1 and FC1 levels in all samples, with FC1 levels at 3.3% of the corresponding FB1 levels. FC4 levels were similar to FC1, whereas only low amounts of FC3 were detected.  相似文献   

12.
The aim of this research was to determine the fate of aflatoxins (AFs) and fumonisins (FBs) naturally occurring in raw materials (maize grit and malted barley) during four industrial brewing processes. The aflatoxin B1 (AFB1) level in raw materials varied from 0.31 to 14.85 µg kg?1, while the fumonisin B1 (FB1) level (only in maize grit) varied from 1146 to 3194 µg kg?1. The concentration in finished beer ranged from 0.0015 to 0.022 µg l?1 for AFB1 and from 37 to 89 µg l?1 for FB1; the other aflatoxins and fumonisin B2 were not found in beer samples. The average percentage of toxins recovered in finished beer, referring to the amounts contained in raw materials, were 1.5% ± 0.8% for AFB1 and 50.7% ± 4.7% for FB1. These results were mainly due to the different solubility of the two mycotoxins during the mashing process. If raw materials comply with the limits fixed by European Commission Regulations, the contribution of a moderate daily consumption of beer to AFB1 and FB1 intake does not contribute significantly to the exposure of the consumer.  相似文献   

13.
The absorption, distribution and elimination of fumonisin B1 (and B2) after oral administration of Fusarium verticillioides (MRC 826) fungal culture, mixed into the experimental feed for 10 days, was studied in weaned barrows. In order to determine the absorption of FB1 from the feed marked by chromium oxide, a special T-cannula was implanted into the distal part of pigs’ ileum. During the feeding of toxin-containing diet (45 mg FB1 kg?1) and until the tenth day after the end of treatment, the total quantity of urine and faeces was collected and their toxin content analysed. At the end of the trial, samples of lung, liver, kidney, brain, muscle, and fat were also collected and their fumonisin content analysed by LC-MS. The fumonisins appeared to decrease the reduced glutathione content in blood plasma and red blood cell haemolysate, possibly associated with in vivo lipid peroxidation. From a data set of 80 individual data and the concentration and rate of C r and fumonisins (FB1, partially hydrolysed FB1 and aminopentol) in the chymus, it could be established that the accumulative absorption of fumonisin B1 was 3.9% ± 0.7%. In the chymus, the FB1 conversions into aminopentol and partially hydrolysed FB1 were 1.0 and 3.9%, respectively. The degree of metabolism in faeces was variable, although the main product was the partially hydrolysed form, with very small amounts of the aminopentol moiety being recovered. In the investigated tissues the FB1 conversion to aminopentol and partially hydrolysed FB1 was 30 and 20%, respectively.  相似文献   

14.
Fumonisin B1 (FB1) is often a co-contaminant with aflatoxin (AF) in grains and may enhance AF's carcinogenicity by acting as a cancer promoter. Calcium montmorillonite (i.e. NovaSil, NS) is a possible dietary intervention to help decrease chronic aflatoxin exposure where populations are at risk. Previous studies show that an oral dose of NS clay was able to reduce AF exposure in a Ghanaian population. In vitro analyses from our laboratory indicated that FB1 (like aflatoxin) could also be sorbed onto the surfaces of NS. Hence, our objectives were to evaluate the efficacy of NS clay to reduce urinary FB1 in a rodent model and then in a human population highly exposed to AF. In the rodent model, male Fisher rats were randomly assigned to either FB1 control, FB1?+?2% NS or absolute control group. FB1 alone or with clay was given as a single dose by gavage. For the human trial, participants received NS (1.5 or 3?g?day?1) or placebo (1.5?g?day?1) for 3 months. Urines from weeks 8 and 10 were collected from the study participants for analysis. In rats, NS significantly reduced urinary FB1 biomarker by 20% in 24?h and 50% after 48?h compared to controls. In the humans, 56% of the urine samples analysed (n?=?186) had detectable levels of FB1. Median urinary FB1 levels were significantly (p?<?0.05) decreased by >90% in the high dose NS group (3?g?day?1) compared to the placebo. This work indicates that our study participants in Ghana were exposed to FB1 (in addition to AFs) from the diet. Moreover, earlier studies have shown conclusively that NS reduces the bioavailability of AF and the findings from this study suggest that NS clay also reduces the bioavailability FB1. This is important since AF is a proven dietary risk factor for hepatocellular carcinoma (HCC) in humans and FB1 is suspected to be a dietary risk factor for HCC and oesophageal cancer in humans.  相似文献   

15.
A total of 57 samples of corn and corn‐based products collected from various districts of Egypt were analyzed for Fusarium mycotoxins (T‐2, diacetoxyscripenol (DAS( deoxynivalenol (DON) and fumonisin B1 (FB1) and aflatoxins. FB1 was detected in about 80%, 53.85%, 33.3%, and 28.57% of yellow corn, corn meal, white corn, and popcorn samples, respectively. The levels of FB1 ranged from 10 to 780 μg/kg. T‐2 and DAS were detected in 5% and 10% of yellow corn samples, respectively, and DON was detected in white corn and popcorn samples at levels of 28.8 and 10.1 μg/kg, respectively. Starch samples were found to be free from Fusarium mycotoxins. Baking balady bread at 450°C/min reduced FB1 to 72.4% while baking Franco bread at 250°C/20 min reduced FB1 to 57.4%. Boiling of macaroni and corn in water completely removed FB1 from contaminated samples. On the other side, corn flakes samples were found to be contaminated with aflatoxins B1 and G1 at levels ranging from 6 to 10 ppm, whereas 2.9% of samples were contaminated with aflatoxin B1 > 35 ppm and G1 > 16 ppm.  相似文献   

16.
Fumonisins B1, B2 and B3 (FB1, FB2 and FB3) and aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) are both major mycotoxins of food concern, because of their wide range of concentration and possible co-occurrence. Therefore, a contamination survey in corn and wheat flour by liquid chromatography–tandem mass spectrometry was carried out. Quantification of fumonisins and aflatoxins was based on internal calibration (by the use of 13C34-fumonisin) and external calibration, respectively. Fumonisins were detected in 95% of corn samples and in 7% of wheat flour samples, with the mean level (FB1?+?FB2?+?FB3) of 441?µg?kg?1 and 0.09?µg?kg?1, respectively. Low levels of aflatoxins were detected in 37% of the samples with a mean level (B1?+?B2?+?G1?+?G2) of 0.12?µg?kg?1. Fumonisins and aflatoxins were not detected in 29% of the samples analysed. Simultaneous occurrence of fumonisins and aflatoxins was observed in 12% of samples.  相似文献   

17.
Fumonisins are well known mycotoxins produced by Fusarium verticillioides, F. proliferatum and other Fusarium species. Many new fumonisins and fumonisin-like compounds have been detected by mass spectrometry in cultures of F. verticillioides. Recently, fumonisins B2 and B4 were produced by Aspergillus niger isolated from coffee and fumonisin B2 in A. niger from grapes. Fumonisin B2 was itself detected in coffee beans, wine and beer, adding to the list of foodstuffs and feedstuffs other than corn (maize) and sorghum in which fumonisins have been found in recent years. Fumonisin B1 (FB1) can bind to proteins (PB FB1) and to other matrix components during food processing involving heat. The occurrence of bound fumonisins in processed corn foods is common. Another type of binding (or association) relates to observed instability of fumonisins in rice flour, corn starch and corn meal at room temperature; this can affect the immunoaffinity column clean-up procedure in analysis of naturally contaminated starch-containing corn foods for fumonisins. The occurrence of N-fatty acylated fumonisin derivatives in retail fried corn foods has also been demonstrated. Bioaccessibility of free FB1 and total bound FB1 (TB FB1) present in corn flakes has been estimated by in vitro digestion experiments. Intentional binding of fumonisins to cholestyramine has been demonstrated in vivo and is a potential means of detoxification of animal feed.  相似文献   

18.
Fusarium species (spp.) and fumonisin B1 (FB1) contaminations were monitored in maize and porridge consumed by a rural population of Limpopo Province, South Africa. Faecal samples were also analysed for FB1 as a means of estimating the degree of dietary exposure to this mycotoxin. In total, 142 samples of maize (n?=?54), porridge (47) and faeces (41) were screened for Fusarium spp. using a serial dilution technique followed by DNA sequencing, while FB1 was further screened and quantified by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), respectively. At least four species of Fusarium were identified, of which F. verticillioides was the most prevalent in all three sample types analysed. The contamination levels of FB1 were significantly higher in 87% of maize sampled (range?=?101–53,863?µg?kg?1) as compared with porridge (74% incidence rate; range?=?0.2–20?µg?kg?1) and faecal samples (100% incidence rate; range?=?0.3–464?µg?kg?1). Thus, it can be deduced that the level of human exposure to FB1 via the consumption of maize was high as several samples contained levels exceeding 1000?µg?kg?1, which was strongly supported by the levels found in faecal samples. Further data revealed that a high proportion of FB1 is destroyed or removed by processing maize into porridge. As maize porridge is consumed as a staple, the low levels found provide a means to limit exposure to FB1. Levels of FB1 found in the faeces which were higher indicate that other foods contaminated with the toxin are also consumed.  相似文献   

19.
In a survey carried out on 87 rotted fig fruits samples collected in the Apulia region of Italy, the authors isolated 126 Fusarium strains identified as F. ramigenum (69 strains), F. solani (49), F. proliferatum (five) and three not identified. Investigation on the fertility of the strains belonging to F. proliferatum and F. ramigenum revealed that only strains of F. proliferatum were fertile. The identity of F. ramigenum strains was confirmed by sequencing a portion of the translation elongation factor-1α gene. When Fusarium species were analysed for their toxigenicity, 37/69 strains of F. ramigenum produced fusaric acid (FA) up to 525 mg kg?1; 30 strains produced beauvericin (BEA) up to 190 mg kg?1; 60 strains produced fumonisin B1 (FB1) and fumonisin B2 (FB2) up to 1575 mg kg?1 of total FBs; and two strains produced fusaproliferin (FUP) up to 345 mg kg?1; all five strains of F. proliferatum produced FA at low levels; two strains produced BEA up to 205 mg kg?1; one strain produced FB1 and FB2, 1100 and 470 mg kg?1, respectively; and one strain produced FUP, 820 mg kg?1; F. solani (30 strains) produced FA, 13 strains up to 215 mg kg?1. Few fungal extracts showed high toxicity toward brine shrimp larvae and in some cases in relation to BEA and FA content. A pathogenic assay on fig fruits showed that all three species were pathogenic, with higher virulence of F. ramigenum. These data report for the first time the production of BEA and FB1/FB2 by F. ramigenum and show that it is a main agent of fig endosepsis in Apulia and can contribute to fumonisin contamination of fresh and dried figs.  相似文献   

20.
In this study a total of 522 samples were collected from Shandong province of China in 2014 and analysed for the occurrence of fumonisin B1 (FB1), FB2 and FB3 by isotope dilution ultrahigh performance liquid chromatography–tandem mass spectrometry. Fumonisins were detected in 98.1% of the corn products, with the average total level of 369.2 μg kg?1. The individual average values of FB1, FB2 and FB3 in corn products were 268.3, 53.7 and 47.2 μg kg?1, respectively. The simultaneous occurrence of FB1, FB2 and FB3 was observed in 76.7% of the corn products. Especially, the results demonstrated that the difference in the contamination levels for fumonisins in these three types of corn products was apparent. In addition, 6.2% of the wheat flour samples were contaminated with FB1, with concentrations ranging from 0.3 to 34.6 µg kg?1. No FB2 or FB3 was detected in wheat flour. In corn oil samples no fumonisins were detected.  相似文献   

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