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1.
The presence of ochratoxin A (OTA), fumonisin B2 (FB2) and black aspergilli in raisins from Western Greece regions (Messinia, Corinthia, Achaia, Ilia and Zante Island) was investigated in relation to the different geographic and climatic conditions in the 2011 growing season. The biseriate species Aspergillus niger “aggregate” and A. carbonarius were mainly identified. The population of A. niger “aggregate” species occurred in all raisin samples at colony-forming units (CFU) concentrations significantly higher (mean 2.2 × 105 CFU g?1 homogenate) than those of A. carbonarius population (mean 4.9 × 103 CFU g?1 homogenate), which occurred in 80% of the raisin samples. OTA was found in 73% of the samples at levels ranging from 0.1 µg kg?1 to 98.2 µg kg?1, with the highest level occurring in a raisin sample from Ilia that also contained the highest level of A. carbonarius. The European Union legal limit for OTA was exceeded in 15% of the raisin samples. FB2 was found in 29% of the raisin samples at levels ranging from 7.1 µg kg?1 to 25.5 µg kg?1, with 20% of the samples co-occurring with OTA. Principal-component analysis was applied to levels of mycotoxins, fungal contamination, geographical data and environmental conditions recorded in the harvesting (August) or drying (September) period. Principal-component analysis clearly indicated a good direct correlation of rainfall and relative humidity with OTA and A. carbonarius contamination. A lack of clustering was observed when A. niger and FB2 contamination were considered. This is the first report on the co-occurrence of the mycotoxins OTA and FB2 in dried vine fruits from Greece.  相似文献   

2.
Based on fungal and fumonisin contamination of 870 freshly harvested samples, the quality of corn used by processing industries in the Northern region of Paraná State, Brazil (2003 and 2004 crop-year) was evaluated. Sampling was carried out for each crop at two points in the production chain, i.e. at reception by the processors and at the pre-drying step. Corn samples were more frequently contaminated with Fusarium sp. (100%) and Penicillium sp. (84.1–95.3%) than Aspergillus sp. (5.6–19.8%). Fumonisin B1 (FB1) was detected in all samples from the two points in both crop-years. FB1 levels ranged 0.02–11.83 µg g?1 in the reception and 0.02–10.98 µg g?1 in the pre-drying samples of the 2003 crop. Samples from the 2004 crop showed FB1 levels ranging 0.03–12.04 µg g?1 in the reception and 0.06–7.74 µg g?1 in the pre-drying samples. FB2 levels ranged 0.02–5.25 µg g?1 in the reception and 0.01–7.89 µg g?1 in the pre-drying samples (2003 crop-year). In samples from the 2004 crop, FB2 levels ranged 0.02–6.12 µg g?1 in the reception and 0.05–3.47 µg g?1 in the pre-drying samples. Low fumonisin levels were detected in most corn samples used by processors in the Northern region of Paraná State, showing a decreasing trend in fumonisin contamination over the years.  相似文献   

3.
The aim of this study was to assess levels of aflatoxin M1 (AFM1) in milk samples from Kerman, Iran. AFM1 was detected in 72 samples, ranging in concentration from <0.01 to 0.41?µg?l?1. The samples were analyzed using immunoaffinity column for clean-up and HPLC for determining AFM1. Milk samples were collected from six dairy farms. AFM1 was found in ~50% of the milk samples. The average level of AFM1 was below the tolerance limit (0.05?µg?l?1), but 50% of the samples had greater levels than the maximum tolerance limit accepted by EU and the Iranian national standard. The method detection limit and limit of quantification were 0.01 and 0.03?µg?l?1, respectively, and recovery of the method was 87%. The results showed that AFM1 contamination is a serious problem for public health. To achieve a low level of AFM1 in milk, cattle feed must be monitored regularly for aflatoxin contamination and protected from fungal contamination as much as possible.  相似文献   

4.
A total of 635 raw milk samples from 45 dairy farms, from three regions of São Paulo state – Brazil, were evaluated during 15 months for aflatoxin M1 (AFM1). AFM1 was determined by high performance liquid chromatograph with fluorescence detection. AFM1 was detected (>0.003 µg kg?1) in 72.9%, 56.3% and 27.5% of the samples from Bauru, Araçatuba and Vale do Paraíba regions, respectively. The mean AFM1 contamination considering all the samples was 0.021 µg kg?1. Furthermore, the concentration of AFM1 was quite different among Bauru (0.038 µg kg?1), Araçatuba (0.017 µg kg?1) and Vale do Paraíba (<0.01 µg kg?1) regions. Only three samples (0.5%) had higher contamination than the tolerated limit in Brazil (0.50 µg kg?1) and 64 samples (10.1%) had a higher contamination than the maximum limit as set by the European Union (0.050 µg kg?1). The estimated AFM1 daily intake was 0.358 and 0.120 ng kg?1 body weight per day for children and adults, respectively.  相似文献   

5.
Shiga toxin-producing Escherichia coli is a common foodborne pathogen which transmission includes dairy products. In the search for novel biocontrol methods, bacteriophages have become important candidates for the eradication of foodborne pathogens. The aim of this study was to evaluate the bacteriophage-mediated reduction of E. coli O157:H7 in raw and filtered milk. Laboratory-scale tests showed that the bacteriophage ECPS-6 efficiently adsorbed to E. coli O157: H7 cells. Furthermore, ECPS-6 remained stable when heated at 70°C for 20 min and in a wide pH range from 3.0 to 11.0. The trials on contaminated milk were performed using filtered and unfiltered raw milk contaminated with 1 × 105 CFU × ml−1 of E. coli O157: H7. Bacteriophage was added at multiplicity of infection (MOI) 5 and 50. The ECPS-6 reached the highest lytic activity at MOI = 5 (25°C) which resulted in 4.74 Log10 CFU × ml−1 and 7.3 Log10 CFU × ml−1 reduction after 10 days for both tested strains, respectively. Under refrigerated conditions (4°C) the quantity of E. coli decreased to 1.5 Log10 CFU × ml−1 and 3.04 Log10 CFU × ml−1 for these strains, respectively. Usage of MOI = 50 for the treatment unfiltered milk led to the reduction of E. coli O157:H7 A-2 below the detection limit after 6 hr.  相似文献   

6.
Aflatoxin B1 (AFB1) levels were evaluated in betel nuts (Areca catechu L.) being imported to Pakistan during 2010–2011. In total, 278 betel nut samples (India = 21, Indonesia = 51, Sri-Lanka = 34 and Thailand = 172) were received from the Department of Customs and were analysed by thin layer chromatography (TLC). All Indian origin betel nuts showed AFB1 contamination ranging from 11.7–262.0 µg kg?1 with a mean of 92.5 µg kg?1. Among Indonesian and Sri Lankan shipments, 80.4% and 73.5% betel nuts were contaminated with AFB1 ranging between 3.3–39.2 and 6.5–103.4 µg kg?1 with a mean of 11.6 and 35.0 µg kg?1, respectively. However, only 30.2% of Thailand origin samples showed AFB1 contamination ranging 3.3–77.0 µg kg?1 with a mean of 6.6 µg kg?1. The widespread occurrence of AFB1 increases the hazard associated with betel nuts. Thus, strict control is a pre-requisite for the production and import/export of psychoactive substances as betel nuts.  相似文献   

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

8.
One hundred and forty-six samples of animal feed (barley, n = 60; wheat bran, n = 22; wheat dry pulp, n = 29; and canola meal, n = 35) were collected in 2011 from Mashhad (Khorasan, Iran). Aflatoxins (AFs) were determined in these samples after immunoaffinity column clean-up by high-performance liquid chromatography (HPLC) with fluorescence detection. Aflatoxin B1 (AFB1) contamination was found in 28 samples: in five of the barley samples (8.3%) at a mean level of 0.48 µg·kg?1, in two wheat bran samples (9.0%) at a mean level of 0.88 µg·kg?1, in 10 wheat dry pulp samples (34.5%) at a mean level of 0.30 µg·kg?1 and in 11 canola meal samples (31.4%) at a mean level of 0.92 µg·kg?1. AFB1 levels were below the maximum levels of Iran regulations (5 µg·kg?1) and the EU maximum limit (5 µg·kg?1).  相似文献   

9.
Many plant pathogens produce toxic metabolites when growing on food and feed. Some antioxidative components seem to prevent fungal growth and mycotoxin formation. Recently, we synthesized a new class of powerful antioxidative compounds, i.e. tetrahydrocurcuminoids, and its structure/antioxidant activity relationships have been established. The South West of France produces large amounts of corn, which can be infected by Fusarium species, particularly F. proliferatum. In this context, the efficiency of tetrahydrocurcuminoids, which can be obtained from natural curcuminoids, was investigated to control in vitro the growth of F. proliferatum and the production of its associated mycotoxin, fumonisin B1. The relation between structure and antifungal activity was studied. Tetrahydrocurcumin (THC1), with two guaiacyl phenolic subunits, showed the highest inhibitory activity (measured as radial growth on agar medium) against the F. proliferatum development (67% inhibition at a concentration of 13.6?µmol?ml?1). The efficiencies of THC2 (36% at a concentration of 11.5?µmol?ml?1), which contains syringyl phenolic units, and THC3 (30% at a concentration of 13.6?µmol?ml?1), which does not have any substituent on the aromatic rings, were relatively close. These results indicate that the simultaneous presence of guaiacyl phenols and the enolic function of the β-diketone moiety play an important role in the inhibition mechanisms. The importance of this combination was confirmed using n-propylguaiacol and acetylacetone as molecular models. Under the same conditions, ferulic acid and eugenol, other natural phenolic antioxidants, were less efficient in inhibiting fungal growth. THC1 also reduced fumonisin B1 production in liquid medium by approximately 35, 50 and 75% at concentrations of 0.8, 1.3, and 1.9?µmol?ml?1, respectively. These very low inhibitory concentrations show that tetrahydrocurcuminoids could be one of the most promising biobased molecules for the control of mycotoxinogen fungal strains.  相似文献   

10.
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   

11.
A simple method permitting the simultaneous determination of trace residues of novobiocin and phenylbutazone in raw milk samples using liquid chromatography-tandem mass spectrometry was developed. Raw milk samples were mixed with acetonitrile to facilitate the concurrent precipitation of milk proteins and extraction of both veterinary drugs. Without additional clean-up or concentration of the resulting extract, the analytes could be quantified at concentrations as low as 0.0025 and 0.001 µg ml?1 for phenylbutazone and novobiocin, respectively. The analysis of a series of fortified raw milk samples at analyte concentrations ranging from 0.005 to 0.1 µg ml?1 and from 0.01 to 0.2 µg ml?1 for phenylbutazone and novobiocin, respectively, yielded average recoveries ranging from 89.2% to 104.3% with standard deviations below 7%. The analytical method was applied to the analysis of raw milk samples collected from transport trucks upon delivery at dairy-processing plants throughout Alberta, Canada. Novobiocin was detected in 13 of 1072 samples tested at concentrations ranging from 0.001 to 0.007 µg ml?1. Phenylbutazone was not detected in any of the samples tested.  相似文献   

12.
Analysis of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) in 76 edible oil samples (peanut oil, soybean oil, corn embryo oil and blended oil) was performed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The oils were sampled from three areas (Shijiazhuang, Baoding and Tangshan) of Hebei Province of China. AFB1 was detected in 22 samples representing 28.9%, followed by AFB2 (7.89%) and AFG1 (3.95%), while no AFG2 contamination was detected in any samples. AFB1 levels in oil samples ranged 0.14–2.72?µg?kg?1 and AFB2 ranged 0.15–0.36?µg?kg?1, while lower levels of 0.01–0.02?µg?kg?1 for AFG1 were recorded. The paper is part of an on-going investigation of aflatoxin contamination in Chinese edible oils.  相似文献   

13.
This survey was carried out to evaluate the occurrence of total aflatoxins (AFs; B1+B2+G1+G2) in unpacked composite spices. A total of 75 samples of composite spices such as biryani, karhai, tikka, nihari and korma masalas were collected from local markets of Karachi, Pakistan, and analysed using HPLC technique. The results indicated that AFs were detected in 77% (n = 58) samples ranging from 0.68 to 25.74 µg kg?1 with a mean of 4.63 ± 0.95 µg kg?1. In 88% (n = 66) samples, AFs level was below the maximum limits (ML = 10 µg kg?1) as imposed by EU. Furthermore, 61% (n = 46) tested samples contained AFs level between 1 and 10 µg kg?1, 9% (n = 7) exhibited AFs contamination ranged 10?20 µg kg?1 and only 3% (n = 2) of the investigated samples contained AFs levels higher than the ML of 20 µg kg?1 for total aflatoxins as set by the USA. It was concluded that there is need to establish a strict and continuous national monitoring plan to improve safety and quality of spices in Pakistan.  相似文献   

14.
The natural co-occurrence of aflatoxins (AFs), ochratoxin A (OTA) and citrinin (CIT) in melon seed samples obtained from retailers and households in Ireland and the United Kingdom (UK) was evaluated. AFs and OTA were determined by HPLC with fluorescence detection while CIT was analysed by HPLC-MS/MS. AFB1 was detected in all (100%) samples (mean = 9.7 μg kg?1; range = 0.2–66.5 μg kg?1). Mean total AFs was 12.0 μg kg?1 (range = 0.3–82 μg kg?1). Commercially retailed samples showed a significantly higher AFB1 contamination (p < 0.05) than the household samples. OTA occurred in 3 (13.6%) samples, while 4 (18.2%) were contaminated with CIT at very low levels. In this study, 68% of the melon seed samples were contaminated above the 2 μg kg?1 EU limit for AFB1 in oilseeds. These results highlight the need for the development of strategies to reduce AF contamination in “egusi” for human consumption.  相似文献   

15.
The aim of this study was to assess mycotoxin contamination of crops grown by rural subsistence farmers over two seasons (2011 and 2012) in two districts, Vhembe District Municipality (VDM, Limpopo Province) and Gert Sibande District Municiality (GSDM, Mpumalanga Province), in northern South Africa and to evaluate its impact on farmers’ productivity and human and animal health. A total of 114 maize samples were collected from 39 households over the two seasons and were analysed using a validated liquid chromatography-tandem mass spectrometry mycotoxins method. Aflatoxin B1 (AFB1) occurrence ranged from 1 to 133 µg kg?1 in VDM while AFB1 levels in GSDM were less than 1.0 µg kg?1 in all maize samples. Fumonisin B1 levels ranged from 12 to 8514 µg kg?1 (VDM) and 11–18924 µg kg?1 (GSDM) in 92% and 47% positive samples, respectively, over both seasons. Natural occurrence and contamination with both fumonisins and aflatoxins in stored home-grown maize from VDM was significantly (p < 0.0001) higher than from GSDM over both seasons.  相似文献   

16.
17.
During 2012–2014, 170 samples of export quality raisins were collected from different vendors in Pakistan. The collected samples were analysed for the presence of aflatoxins (AFs) and Ochratoxin A (OTA) contamination using high-performance liquid chromatography technique. The limit of detection and limit of quantification of AFs/OTA were 0.12/0.10 and 0.36/0.30 µg kg?1, respectively. Only 5% of the samples were contaminated with AFs, ranging 0.15–2.58 µg kg?1 with a mean of 0.05 ± 0.26 µg kg?1. None of the raisin samples exhibited AFs contamination above the maximum limit (ML = 4 µg kg?1) as set by the European Union (EU). About 72% of the samples were contaminated with OTA, ranging 0.14–12.75 µg kg?1 with a mean of 2.10 ± 1.9 µg kg?1. However, in 95.3% of the tested samples, OTA level was lower than the ML of 10 µg kg?1 as regulated by the EU. Apparently, a strict and continuous monitoring plan, including regulatory limits, improves food safety and quality for all types of commodities.  相似文献   

18.
A sensitive LC–MS/MS method for the simultaneous determination of type A, B and D trichothecenes in cereals is presented. The limits of detection ranged between 0.1 and 0.7 µg kg?1 for all analytes. The method was applied to 289 representatively drawn samples of wheat, rye and oat products. Ninety-four percent of the wheat samples (n = 130), 95% of the rye samples (n = 61) and 100% of the oat samples (n = 98) were contaminated with the type A trichothecenes T-2 and HT-2 toxin. Median levels of T-2/HT-2 (sum of the toxins) were 0.91, 0.53 and 8.2 µg kg?1, respectively. Highest levels were found in wheat bran (24 µg kg?1), rye kernels (3.1 µg kg?1) and oat flakes (85 µg kg?1). All wheat and rye samples and 75% of the oat samples were contaminated with the type B trichothecene deoxynivalenol. Median levels of this toxin were 23, 15 and 0.53 µg kg?1, respectively. Highest levels were found in wheat bran (1160 µg kg?1), rye kernels (288 µg kg?1) and oat flakes (55 µg kg?1). The type B trichothecene nivalenol was detected in 67% of the wheat samples, in 3% of the rye samples and in 24% of the oat samples with highest levels in wheat bran (96 µg kg?1), rye kernels (1.8 µg kg?1) and in oat flakes (17 µg kg?1), respectively. Levels of other type A and B trichothecenes played a minor role, although the rates of contamination were often high. Neither macrocyclic type D trichothecenes (satratoxin G and H, verrucarin A, roridin A) nor diacetylverrucarol and verrucarol (type A trichothecenes), were detected in any of the samples.  相似文献   

19.
A method combining multiplex real-time polymerase chain reaction (PCR) with high-resolution melting (HRM) analysis for rapid and specific simultaneous detection of Salmonella, Listeria monocytogenes, and Staphylococcus aureus was developed. The method included a melting-curve analysis of products and was evaluated by specificity, sensitivity and reproducibility analyses. Sensitivity and reproducibility analyses was both conducted by genomic DNA extracted from serial dilutions for each target pathogen. Assays with artificially inoculated and naturally contaminated samples after enrichment were also conducted. In the specificity test, there was no nonspecific amplification of the 44 nontarget pathogens, whereas the actual T m values were 79.38?±?0.14, 82.54?±?0.15, and 77.36?±?0.14 °C for Salmonella, L. monocytogenes, and S. aureus, respectively. The sensitivity of the method was 3.5?×?102 CFU ml?1 for Salmonella and L. monocytogenes and 3.5?×?103 CFU ml?1 for S. aureus. The coefficients of variation of T m values ranged 0.51–1.03 % for Salmonella, 1.63–2.11 % for L. monocytogenes, and 0.75–2.17 % for S. aureus in intraassay, and ranged 0.81–2.43 % for Salmonella, 1.97–2.35 % for L. monocytogenes, and 0.93–3.93 % for S. aureus in interassay. The detection limit in artificially inoculated samples (n?=?50) was 5 CFU (25 g)?1 food for the three tested pathogens. In the naturally contaminated samples (n?=?120),Salmonella DNA was detected by HRM, sequencing, and conventional culture-based methods at a positive rate of 25.00, 25.00, and 24.17 %, respectively; the corresponding rates for L. monocytogenes were 14.17, 14.17, and 14.17 %, respectively, while those for S. aureus were 16.7, 16.7, and 16.7 %, respectively.  相似文献   

20.
Chilli peppers from Pakistan are consumed locally and also exported. Their quality is compromised by aflatoxins (AF) contamination. AF in chillies from rural, semi-rural and urban areas of the Punjab region of Pakistan were determined. Twenty-three (52.3%), 22 (50%) and 29 (65.9%) samples from rural, semi-rural and urban areas respectively, contained levels of aflatoxins which exceeded the European Union limits of >5?µg?kg?1 for AFB1 and >10?µg?kg?1 for total AF that apply to spices. Mean values for AFB1 in ground samples were 23.8, 14.8 and 14.0?µg?kg?1 for rural, semi-rural and urban areas, respectively. Mean total AF in ground samples were 27.7, 17.7 and 16.2?µg?kg?1 from equivalent locations. Eleven (50%), 12 (54.5%) and 14 (63.6%) whole samples from rural, semi-rural and urban areas, respectively, contained total levels of AF that exceeded European Union limits. The data indicate that individual localities have particular problems. In conclusion, the concentrations were often greater than the statutory limits set by the European Union.  相似文献   

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