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1.
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   

2.
Traditional and improved varieties of maize, pearl millet and sorghum were planted by small-scale farmers under the direction of the International Institute for Tropical Agriculture in two Nigerian agro-ecological zones: the Sudan Savanna and the Northern Guinea Savanna. Samples were collected for the determination of Fusarium infection and fumonisin (B1, B2 and B3) contamination. A previous paper reported Aspergillus infection and aflatoxin contamination of these samples. Fusarium infection levels, measured by per cent kernels infected, were modest with mean levels for the above cereals of 16% ± 11% (SD), 12% ± 7% and 13% ± 16%, respectively. However, the Fusarium species recovered from maize were predominantly the fumonisin producers F. verticillioides and F. proliferatum, together making an infection rate of 15% ± 10%, whereas these species were present to a limited extent only in the other two cereals, 1% ± 1% for pearl millet and 2% ± 6% for sorghum. Fumonisin contamination was variable but reflected the diversity of Fusarium producers in these three cereals. Mean levels were 228 ± 579 µg kg–1 (range < 5–2860 µg kg–1) for maize, 18 ± 7 µg kg–1 (range = 6–29 µg kg–1) for pearl millet and 131 ± 270 µg kg–1 (range < 5–1340 µg kg–1) for sorghum. Together with previous results on aflatoxin, this study confirmed the co-occurrence of aflatoxins and fumonisins in maize as well as in the traditional African cereals, millet and sorghum (89% co-occurrence across all three cereals). The low fumonisin levels may be ascribed to the use of good agricultural practices. Of the Fusarium species present, those in maize consisted mainly of fumonisin producers, the opposite of what was observed in pearl millet and sorghum. It is concluded that replacement of maize by pearl millet and sorghum could improve food safety with regards to aflatoxin B and fumonisin B exposure.  相似文献   

3.
The main objective of this research was to perform an exposure assessment of aflatoxins intake through consumption of maize products in Serbia, Croatia, and Greece. Food consumption survey of maize-based products has been performed during 2017 in the three countries with at least 1,000 interviewees per country covering their dietary habits and body weight. Values for the concentration of aflatoxins were extracted from available research published in the last ten years. Finally, a Monte Carlo analysis of 100,000 iterations was performed to estimate the intake of aflatoxins from consumption of maize-based products. Results revealed that the estimated average exposure of adults to aflatoxins, from maize consumption, in each of the three countries was between 0.44 ng kg?1 bw day?1 and 5.59 ng kg?1 bw day?1. Margin of exposure values for the mean exposure levels, in all three countries, were between 30 and 389. Estimations for hepatocellular carcinoma cases/year/105 individuals, depending on the HBsAg+ prevalence, were 0.075–0.098, 0.006–0.008 and 0.020–0.026 for Serbia, Croatia and Greece, respectively.  相似文献   

4.
Dehulling of maize grains as an aflatoxin decontamination method was investigated. Sixty kilograms of maize (whose average moisture content was 110 g kg?1) were thoroughly mixed and divided into two samples. The kernel moisture content of one sample was adjusted to 200 g kg?1 while the other (control) was left at 110 g kg?1. The two samples were kept at ambient temperature (25–30 °C) for 21 days. Twenty sub‐samples, ten from each, were further divided into two so that one lot was dehulled while the other was not dehulled. These sub‐samples were then milled to pass through a 1 mm screen and the meal was evaluated for aflatoxin contamination. It was found that there was a 92% decrease in aflatoxin levels in dehulled maize meal compared with undehulled maize meal. We therefore suggest that dehulling the grain can be used to reduce aflatoxin levels in maize. Copyright © 2005 Society of Chemical Industry  相似文献   

5.
The aim was to evaluate the distribution of aflatoxins and fumonisins in fractions derived from the dry-milling of contaminated maize. Two maize lots with different contamination levels were processed and sampled: the first (maize 1) had aflatoxin B1 (AFB1) and fumonisin B1 (FB1) levels of 3.6 and 5379 µg kg?1, respectively; the second (maize 2) had corresponding levels of 91.1 and 8841 µg kg?1, respectively. The cleaning step reduced AFB1 and FB1 levels by 8 and 11% in maize 1 and by 57 and 34% in maize 2. The subsequent removal of bran and germ led to a further decrease in contamination levels in the products destined for human consumption. In the latter, AFB1 was uniformly distributed, while FB1 was concentrated in the finer size fractions. Contamination of raw maize 1 (3.6 µg kg?1) was below the European Union AFB1 limit of 5 µg kg?1 for unprocessed maize, but among the final products only coarse flour (1.7 µg kg?1) was within the European Union limit of 2 µg kg?1, while grits and fine flour showed higher levels (2.7 and 2.5 µg kg?1, respectively). As regards cleaned maize, a different distribution of the two toxins was observed in the kernels: AFB1 contamination was more superficial and concentrated in germ, while FB1 contamination affected the inner layers of the kernels.  相似文献   

6.
A survey of 11 mycotoxins in 348 wheat flour samples marketed in Hebei province of China were analysed by liquid chromatography-tandem mass spectrometry, was carried out. The selected mycotoxins consisted of four aflatoxins (AFs: AFB1, AFB2, AFG1 and AFG2) and seven Fusarium toxins, i.e. deoxynivalenol (DON), nivalenol, 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol, zearalenone, Fusarenon-X and deoxynivalenol-3-glucoside. Results indicated that most of the wheat samples analysed were contaminated with mycotoxins. Wheat was most susceptible to DON (91.4% contamination), with a mean level of 240 μg kg?1. On average the probable daily intake (PDI, expressed as µg kg?1 body weight day?1) of mycotoxins was within the provisional maximum tolerable daily intake (PMTDI, 2.0 µg kg?1 of body weight day?1) as set by the Joint FAO/WHO Expert Committee on Food Additives. Nevertheless, exposure assessment revealed that the maximum PDI of mycotoxins was 4.06 µg kg?1 body weight day?1, which was twice the PMTDI value. Thus, consistent monitoring is recommended, as to keep the contamination level under control.  相似文献   

7.
A survey was undertaken of a total of 120 farmers, 40 from each of the three studied agro-ecological zones of Tanzania, to determine local post-harvest management practices associated with aflatoxin (AF) and fumonisin (FB) contamination of maize. Data on practices (collected using a structured questionnaire) and maize samples were obtained from each of the 120 farmers. FB and AF contamination in the samples were analysed by HPLC. A total of 45% and 85% of maize samples were positive for AF and FB respectively, with levels ranging from 0.1 to 269 μg kg?1 for AF and from 49 to 18 273 μg kg?1 for FBs. Significant differences in contamination level were observed among the three agro-ecological zones. Farmers in the three agro-ecological zones practised similar practices in varying degrees. Drying, sorting and protecting maize against insect infestation are practices that showed significant association with AF or FB contamination of maize. Drying maize on mat/raised platform, sorting (damaged, discoloured and moulded grains) and application of synthetic insecticides during storage are practices that were associated with less contamination of maize with AF and FB. The results can be used to advise on effective post-harvest strategies for prevention of AF and FB contamination of maize in rural Tanzania.  相似文献   

8.
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   

9.
In Mexico, maize tortillas are consumed on a daily basis, leading to possible aflatoxin exposure. In a survey of 396 2-kg samples, taken over four sampling days in 2006 and 2007 from tortilla shops and supermarkets in Mexico City, aflatoxin levels were quantified by HPLC. In Mexico, the regulatory limit is 12?µg?kg?1 total aflatoxins for maize tortillas. In this survey, 17% of tortillas contained aflatoxins at levels of 3–385?µg?kg?1 or values below the limit of quantification (<LOQ) and, of these, 13% were >12?µg?kg?1 and 87% were below the regulatory limit. Average aflatoxin concentrations in 56 contaminated samples were: AFB1 (12.1?µg?kg?1); AFB2 (2.7?µg?kg?1); AFG1 (64.1?µg?kg?1) and AFG2 (3.7?µg?kg?1), and total AF (20.3?µg?kg?1).  相似文献   

10.
The paper’s main purpose is to estimate the dietary exposure to lead for the inhabitants of Jiangsu province, China. Lead concentration data were obtained from the national food contamination monitoring programme during 2007–10. Food samples (n = 2077) were collected from 23 food categories in Jiangsu province. Consumption data were derived from Chinese national nutrition and health survey in 2002, which included 3938 inhabitants from 1451 households in Jiangsu province. Concentration data were combined with consumption data to estimate the dietary intake for the inhabitants of 2–6, 7–17 and 18–80 years, respectively. The β-binomial–normal (BBN) model was used to estimate the long-term intake for the population in Jiangsu province. The distribution of individual margin of exposure (IMoE) was introduced to assess the health effect. Uncertainty of IMoE was quantified by Monte Carlo and bootstrap methods. The mean levels of dietary exposure to lead were estimated at 3.019 µg kg?1 bw day?1 for children aged 2–6 years, 2.104 µg kg?1 bw day?1 for teenagers aged 7–17 years, and 1.601 µg kg?1 bw day?1 for adults aged 18–80 years. The mean intakes for the urban and rural populations were 1.494 and 1.822 µg kg?1 bw day?1, respectively. From the 25th to 99.9th percentiles, IMoE was 0.125–2.057 for 2–6 years and 0.473–7.998 for 18–80 years, respectively. The distribution of IMoE could indicate a public health concern on lead for the Chinese population in Jiangsu. Control measures should be taken to reduce lead exposure in Jiangsu province.  相似文献   

11.
BACKGROUND: Most of the maize silage stored in horizontal silos is exposed to air and can be spoiled by fungi. Potentially toxigenic fungi have been found in maize silage, and about 300 mycotoxins have been detected. Among these mycotoxins, the most harmful for feed and food safety are aflatoxins. The aim of the study was to set up a specific method to detect aflatoxins in maize silage, and to investigate whether aflatoxin contamination in maize silage depends on the level of field contamination of the crop, and whether the occurrence of aerobic spoilage during ensiling has any effect on the final contamination of the silage. RESULTS: A method for the determination of aflatoxin B1, B2, G1 and G2 in maize silage using high‐performance liquid chromagraphy with fluorescence detection has been developed and validated. Recoveries of aflatoxin B1, B2, G1, and G2 spiked over the 0.25 to 5 µg kg?1 range averaged 74–94%. The results of laboratory scale and farm scale ensiling experiments indicated that aflatoxins could increase when silage is exposed to air during conservation or during the feed‐out phase. CONCLUSIONS: The method here proposed to detect aflatoxins in silages has proved to be sensitive and is able to detect levels of 0.1 and 0.5 ng mL?1 for AFB1 and AFG1, and between 0.025 and 0.125 ng mL?1 for AFB2 and AFG2. This study also provides evidence of aflatoxin accumulation in whole crop maize silage as a result of aerobic exposure. Copyright © 2011 Society of Chemical Industry  相似文献   

12.
The potential influence of dietary phytoestrogen exposure on human health during different life phases including early childhood is a matter of scientific debate. In order to improve the risk–benefit assessment of exposure to dietary phytoestrogen, reliable and age-stratified exposure data are desirable. For contributing to the database on phytoestrogen exposure, in the present study plant-derived foods from the Chinese market were analysed by LC-MS/MS for their contents of phytoestrogens, including daidzein, genistein, secoisolariciresinol, glycitein and coumestrol. The analytical data showed the presence of phytoestrogens in a concentration range of less than 0.1 to about 50 μg g?1. Dietary intake was assessed on the basis of average food intake data obtained from interviewing 1000 randomly selected people with the help of food frequency questionnaires. Based on the overall population sampled, the average total phytoestrogen intake was estimated at 232 μg kg?1 day?1. Genistein contributed to about 66%, secoisolariciresinol and glycitein to about 10% each, and daidzein to about 7% of the overall intake. Coumestrol was present only in trace amounts. Age-related exposure assessment indicated that pre-pubertal children (aged 0–14 years) were exposed at the highest level with an average total phytoestrogen intake of 621 μg kg?1 day?1. The substantially higher average exposure of children as compared with adults should trigger further research into the potential health effects of early life exposure to phytoestrogen.  相似文献   

13.
Direct analysis in real time (DART) ionisation coupled to a high-resolution mass spectrometer (MS) was used for screening of aflatoxins from a variety of surfaces and the rapid quantitative analysis of a common form of aflatoxin, AFB1, extracted from corn. Sample preparation procedure and instrument parameter settings were optimised to obtain sensitive and accurate determination of aflatoxin AFB1. 84:16 acetonitrile water extracts of corn were analysed by DART-MS. The lowest calibration level (LCL) for aflatoxin AFB1 was 4 μg kg–1. Quantitative analysis was performed with the use of matrix-matched standards employing the 13C-labelled internal standard for AFB1. DART-MS of spiked corn extracts gave linear response in the range 4–1000 μg kg–1. Good recoveries (94–110%) and repeatabilities (RSD = 0.7–6.9%) were obtained at spiking levels of 20 and 100 μg kg–1 with the use of an isotope dilution technique. Trueness of data obtained for AFB1 in maize by DART-MS was demonstrated by analysis of corn certified reference materials.  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 natural occurrence of fungi, mycotoxins and fungal metabolites was investigated in 100 samples of maize grains collected from south and southwestern Ethiopia in 2015. The maize samples were contaminated by Fusarium, Aspergillus and Penicillium species. Using liquid chromatography tandem mass spectrometry 127 secondary metabolites were analysed. Zearalenone was the most prevalent mycotoxin, occurring in about 96% of the samples. Zearalenone sulfate was the second most prevalent, present in 81% of the samples. Fumonisin B1 was detected in 70% of the samples with a mean level of 606 μg kg?1 in positive samples, while FB2, FB3 and FB4 were detected in 62%, 51% and 60% of the maize samples with mean levels of 202, 136 and 85 μg kg?1, respectively. Up to 8% of the samples were contaminated with aflatoxins, with a maximum level of aflatoxin B1 of 513 μg kg?1. Results were higher than earlier reports for maize from Ethiopia.  相似文献   

16.
The effect of water activity (aw = 0.95, 0.98 and 0.995), temperature (15, 25 and 30°C), incubation time (7, 14, 21 and 28 days), and their interactions on growth and moniliformin (MON), beauvericin (BEA), fusaproliferin (FUS) and fumonisin B1 (FB1) production by two strains of Fusarium temperatum isolated from Argentinean maize were determined in vitro on sterile layers of maize grains. The results showed that there was a wide range of conditions for growth and mycotoxins production by F. temperatum. Both strains were found to grow faster with increasing aw and at 30°C. In relation to mycotoxin production, the two strains produced more FUS than the other mycotoxins regardless of aw or temperature evaluated (maximum = 50 000 μg g?1). For FUS, MON and BEA, the maximum levels were observed at 0.98 aw and 30°C (50 000, 5000 and 2000 μg g?1 respectively). The lowest levels for these three mycotoxins were detected at 15°C and 0.95 aw (1700 and 100 μg g?1 for FUS and MON respectively), and at 0.98 aw (400 μg g?1 for BEA). The maximum levels of FB1 were produced at 15°C and 0.98 aw (1000 μg g?1). At all aw and temperatures combinations evaluated there was an increase in toxin concentrations with time incubation. The maximum levels were detected at 21 days. Statistical analyses of aw, temperature, incubation time, and the two- and three-way interactions between them showed significant effects on mycotoxins production by F. temperatum. For its versatility on growth and mycotoxin production, F. temperatum represents a toxicological risk for maize in the field and also during grain storage.  相似文献   

17.
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   

18.
ABSTRACT

The aim of the study was to assess the dietary intake of caramel colours and their by-products 4-methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) for the Chinese population. Based on the typical and maximum reported use levels of caramel colours in 15 food categories, the dietary intakes of combined and single-class caramel colours of Classes I, III and IV were estimated with the food consumption data from the China National Nutrient and Health Survey. Using the mean values of 4-MEI and THI contents in Class III and Class IV Caramel colour samples, the exposures to 4-MEI and THI from dietary caramel colours were derived. The results showed that the combined and individual average dietary caramel colour intakes for the Chinese population of different age groups were estimated to be 232–60.3 mg kg?1 bw day?1 for combined caramels, 5.9–29.2 mg kg?1 bw day?1 for Class I, 7.7–29.6 mg kg?1 bw day?1 for Class III, 21.2–54.3 mg kg?1 bw day?1 for Class IV, which were far below the group acceptable daily intake (ADI) and respective ADIs. The combined intake of 4-MEI from Class III and IV caramel colours was estimated to be 3.8–5.2 μg kg?1 bw day?1 on average, and 12.9–27.1 μg kg?1 bw day?1 at 95th-97.5th percentile for the general population. The anticipated exposure to THI from Class III caramel colours was estimated to be 0.1–0.3 μg kg?1 bw day?1 on average and 0.5–1.7 μg kg?1 bw day?1 at 95th–97.5th percentile for the general population. The dietary caramel colours intakes and the exposures to 4-MEI and THI from dietary caramel colour for the Chinese population were considered to be of low health concern based on the present toxicological data. Soy sauce, vinegar and compound seasonings were found to be the main contributors to the dietary intake of caramel colours.  相似文献   

19.
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   

20.
The aflatoxin intake through the consumption of maize was assessed in 12 households in a rural population in southern India. This was based on the measurement of aflatoxin levels in cooked maize and the quantity of consumption of the maize. The average aflatoxin intakes in nine out of 12 household ranged from 0·33 to 1·5 μg day-1. Individual intakes varied from 0·08 to 2·22 μg day-1. When assessed on a body weight basis, aflatoxin intakes in the younger age groups were observed to be higher. The average intakes in different age groups 1–5, 5–12, 12–18 and above 18 years were observed to be 47, 35, 33 and 22 ng kg-1 body weight day-1, respectively. Aflatoxin intakes calculated from aflatoxin levels in maize before cooking tended to be higher by 36% when compared with intakes calculated from cooked maize. This significant difference (P<0·001) was attributed to the effect of cooking on aflatoxin levels in maize. © 1997 SCI.  相似文献   

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