Natural occurrence of type-B trichothecene mycotoxins in Korean cereal-based products

Type-B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), fusarenone-X (FUS-X), 15-acetyldeoxynivalenol (15ADON), and 3-acetyldeoxynivalenol (3ADON)) were determined in 338 cereal-based products. Detection limit, quantification limit and mean recovery for five toxins were in the ranges 0.7–2.6?µg?kg^?1, 2.1–7.8?µg?kg^?1 and 73–110%, respectively. The range of occurrence and average level in samples were, respectively, 21–88% and 5.2–121.8?µg?kg^?1 for NIV, 10–96% and 1.7–109.5?µg?kg^?1 for DON, 2–39% and 0.4–3.6?µg?kg^?1 for FUS-X, 0–80% and 0–17.3?µg?kg^?1 for 15ADON, and 0–29% and 0–1.5?µg?kg^?1 for 3ADON. Regarding co-occurrence, 64% of samples had more than two type-B trichothecenes. The estimated daily intakes of NIV, DON, FUS-X, 15ADON, and 3ADON were 0.077, 0.048, 0.004, 0.006 and 0.002?µg?kg^?1?bw?day^?1, respectively. These results suggest that current exposure levels do not indicate the possibility of adverse effects, but consideration of the combined exposure of type-B trichothecenes may be required due to the high frequency of co-occurrence.     

Natural occurrence of Fusarium toxins in peanut,sorghum and maize from Mysore (India)

Peanut, sorghum and maize samples were collected from the wholesale market in Mysore, India, over a period of one year (October 1984 to September 1985). The samples were analysed for the natural occurrence of T-2 toxin (T-2), diacetoxyscirpenol (DAS) and zearalenone by thin-layer chromatography, dermal toxicity test and gas chromatography. Of the total number of peanut samples analysed, 6.9% were positive for the toxic trichothecene(s) (T-2, up to 38.89 mg kg^?1; DAS, up to 2.03 mg kg^?1); 4.8% of total sorghum samples analysed contained T-2 up to 15 mg kg^?1. Zearalenone was not found in any of the samples tested, and no toxins were detected in any of the maize samples. Samples marketed during winter and summer periods were contaminated with the toxins. All the toxin-positive samples except one peanut sample were found in produce stored for more than a week.     

Deoxynivalenol and zearalenone in Fusarium-contaminated wheat in Mexico City

Fusarium spp. invasion causes head blight, a destructive disease in the world's main wheat-growing areas, and deoxynivalenol (DON) and zearalenone (ZEA) contamination in cereal-based products. No data are available on the relationship between Fusarium spp. on commercial wheat samples in Mexico City and the presence of mycotoxins. A total of 30 wheat samples were subject to a PCR method involving genes of the trichothecene and zearalenone biosynthesis pathways to detect the presence of Fusarium. Detection and quantification of DON and ZEA was performed using liquid chromatography coupled to UV detection. PCR indicated the presence of the Tri5 and PKS4 genes in 16.7 and 23.3% of samples, respectively. DON and ZEA contamination was found in 51.2 and 71.4% of samples, respectively, where a positive amplification was obtained. This work presents up-to-date information on mycotoxin contamination in Mexico, where improved contamination/exposure data and firm control/monitoring measures are needed.     

Mycotoxin occurrence in commodities,feeds and feed ingredients sourced in the Middle East and Africa

Between February and October 2009, 324 grain, feed and feed commodity samples were sourced directly at animal farms or feed production sites in Middle East and Africa and tested for the presence of A- and B-trichothecenes, zearalenone, fumonisins, aflatoxins and ochratoxin A, or for selected groups of mycotoxins only. Samples were analyzed after clean-up by immunoaffinity or solid-phase extraction followed by HPLC with derivatization where appropriate and fluorescence, UV or mass spectrometric detection. The percentage of positive samples of B-trichothecenes ranged from 0 to 87% of tested samples. The prevalence of fumonisins in the different countries was >50% in most cases. Zearalenone was present in tested commodities from all countries except three. The presence of aflatoxin in analyzed samples varied from 0 to 94%. Ochratoxin A was present in 67% of samples in Sudan and in 100% of Nigerian samples. No A-trichothecenes were found in this survey.     

Determination and occurrence of zearalenone in cereals and mixed feeds

An HPLC method with fluorescence detection is described for the determination of zearalenone in cereals and mixed feeds. Samples are extracted with chloroform at low pH and cleaned up using an acid-base treatment or gel-permeation chromatography (GPC). Mixed feeds must additionally be cleaned up with extraction columns, because of their different compositions. With the extraction procedure described and GPC clean-up, ochratoxin A can be determined simultaneously. The limit of determination for zearalenone is 2.5 micrograms/kg. The average recovery rate, tested in the range 3.5 to 85 micrograms/kg was found to be 97%. Using this method, 91 samples of cereals and mixed feeds, harvested in 1989, were examined. The contamination rate was 42%. The results are discussed.     

Trichothecenes and zearalenone production by Fusarium equiseti and Fusarium semitectum species isolated from Argentinean soybean

Fusarium equiseti and Fusarium semitectum represent the most abundant species in the Fusarium complex isolated from flowers, soybean pods and seeds in Argentina. The aim of the present study was to assess the production of major type A and type B trichothecenes (diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin, nivalenol, deoxynivalenol) and zearalenone by 40?F. equiseti and 22 F. semitectum isolates on rice culture. Mycotoxins were determined by HPLC with fluorescence detection after derivatisation with 1-anthronylnitrile for type A trichothecenes (i.e. diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin), by HPLC with UV detection for type B trichothecenes (i.e. nivalenol and deoxynivalenol), and by TLC for zearalenone. A total of 22 of 40?F. equiseti isolates produced diacetoxyscirpenol, nivalenol and ZEA alone or in combination, whereas only two of 20?F. semitectum isolates were nivalenol and ZEA producers. Both Fusarium species did not produce any deoxynivalenol, neosolaniol, T-2 toxin and HT-2 toxin. The variable retention in toxigenicity displayed by both fungal species suggests that these species have a saprophytic lifestyle in the soybean agroecosystem in Argentina.     

Modelling thermal degradation of zearalenone in maize bread during baking

The thermal degradation of zearalenone (ZEA) was investigated using a crust-like model, representing maize bread, which was prepared with naturally contaminated maize flour. Model samples were heated under isothermal conditions at the temperature range of 100–250°C. No reduction was observed at 100°C. Thermal degradation rate constants (k) were calculated as 0.0017, 0.0143 and 0.0216?min^?1 for 150, 200 and 250°C, respectively. Maize bread baked at 250°C for 70?min was used to test the capability of model kinetic data for the prediction of ZEA reduction. The time–temperature history in the crust and crumb parts was recorded separately. Partial degradation of ZEA at each time interval was calculated by means of the corresponding k-values obtained by using the Arrhenius equation, and the total reduction occurring at the end of the entire baking process was predicted. The reduction in the crumb and crust of bread was also experimentally determined and found to be consistent with the predicted values. It was concluded that the kinetic constants determined by means of the crust-like model could be used to predict the ZEA reduction occurring during baking of maize bread.     

高效液相色谱法定量检测玉米油中玉米赤霉烯酮的溶剂萃取预处理方法研究

研究了高效液相色谱法(HPLC)定量检测精炼玉米油中玉米赤霉烯酮(ZEN)的溶剂萃取预处理方法,优化了溶剂萃取预处理条件并进行了方法的评估。结果表明:溶剂萃取预处理的最优条件为乙腈-水(体积比9∶1)混合溶液萃取、料液比1∶4、超声萃取时间20 min,该萃取预处理条件可实现ZEN准确定量测定,检出限达4.5μg/kg;10、100、1 000μg/m L加标水平下的加标回收率分别为77.9%、105.7%、95.0%,相对标准偏差2.05%~8.43%,优于传统免疫亲和柱净化预处理方法。     

Determination of nitrofurans residues in animal feeds by flow injection chemiluminescence procedure

A simple flow injection chemiluminescence (FI-CL) method was developed for the rapid and sensitive determination of nitrofurans, including furazolidone, nitrofurantoin and nitrofurazone, in animal feeds based on its chemiluminescence induced by potassium permanganate in sulphuric acid medium. The method involves the injection of nitrofuran samples or standards into H₂SO₄ carrier stream, which then merges at a T-piece with a reagent stream consisting of KMnO₄ in the H₂SO₄ carrier solution. The elicited chemiluminescence intensity of the resulting reaction mixture was measured by photomultiplier tube operated at a voltage of 950 V. Optimum CL signals were given using 2.5 × 10⁻⁵ mol L⁻¹ potassium permanganate in 0.1 mol L⁻¹ sulphuric acid as an oxidant stream and a carrier stream of 0.1 mol L⁻¹ sulphuric acid with a total flow rate of 7.0 mL min⁻¹. Results detailing the optimisation of the analytical signal, calibration, and common interferences of animal feeds were also discussed. The proposed FI-CL method was successfully applied to the determination of nitrofurans in animal feeds, with excellent recoveries, as the determination is free from interference. The method validation has been compared versus HPLC method for animal feed samples.     

Agricultrue group symposium toxins and other harmful sbstances in animal feeds

The following are summaries of papers presented a t the joint meeting of the Agriculture Group and the Society of Feed Technologists at 14 Belgraue Square, London, on 15 November 1977.     

Natural incidence of zearalenone in Croatian pig feed,urine and meat in 2014

The aim of this study was to determine the levels of zearalenone (ZEN) in different feed materials and feedstuffs for pigs, as well as in pig urine and pig meat following contaminated feed consumption. In total, 253 feed material and feedstuff samples were collected from Croatian pig farms. The results revealed the presence of ZEN in significant concentrations, the maximal being found in maize (5522 µg/kg), wheat (3366 µg/kg) and pig fattening feed (1949 µg/kg). In farms in which high feed contamination and pig hyperestrogenism were observed, samples of pig urine (n = 30) and meat (n = 30) were retrieved as well. The mean ZEN concentrations in pig urine and pig meat were 206 ± 20.6 µg/L and 0.62 ± 0.14 µg/kg, respectively. Despite high contamination of feedstuffs responsible for farmed pigs’ intoxication, ZEN levels determined in pig meat were shown to be of little significance for human safety.     

Polymerase chain reaction detection of bacterial ribosomal genes from fresh and stored animal feeds

Feed quality can be influenced by both the microbial population levels and types of organisms that become associated with the feed matrices during processing and storage. Evaluation of microbial quality of animal feeds is difficult, because feeds generally contain a diverse bacterial population that can fluctuate widely depending on a variety of factors. Microbial diversity may be investigated in animal feed using the polymerase chain reaction (PCR) and 16S rDNA primers. In this study a bacterial isolation step involving centrifugation was combined with several DNA extraction techniques, and PCR amplicons were visualised on electrophoresis gels. Seven different animal feeds and two commonly used feed ingredients, either fresh or stored for approximately 14 months at ?20 °C, were chosen (18 feed sources in total) to represent a variety of different matrices, concentrations of macronutrients such as protein and fat, and particle sizes. DNA extraction involving polyethylene glycol 8000 appeared to be the most reliable protocol for the extraction of community DNA for PCR analysis of feeds. The majority of the feeds (14 out of 18 animal feeds and feed ingredients) examined in this study yielded at least one PCR‐positive replicate (1.1 kb band on gel), whereas no amplified products could be obtained from either of the other two DNA extraction protocols. Although some protocol refinement may be necessary for individual feeds, this approach has the potential to be a reliable method for monitoring microbial diversity changes in feeds and for rapid, simultaneous detection of a wide variety of micro‐organisms in animal feeds during processing and storage. © 2002 Society of Chemical Industry     

Natural occurrence of zearalenone and toxicogenic fungi in amaranth grain.

Zearalenone was detected as the natural contaminant in two samples of Amaranthus cruentus grains (1980 micrograms/kg and 420 micrograms/kg, respectively). Fungi isolated from these samples were screened for mycotoxin production. Two of eight isolates of Fusarium (F. equiseti and F. moniliforme) produced zearalenone. One of four isolates of Aspergillus flavus and all four isolates of A. parasiticus produced aflatoxins. Other species potentially toxicogenic such as Aspergillus versicolor, Penicillium viridicatum, P. puberulum, P. crustosum, P. citrinum, P. expansum and Fusarium solani were also found.     

响应面法优化活性炭吸附脱除玉米油中玉米赤霉烯酮

以碱炼脱酸玉米油为原料,考察了不同型号活性炭对玉米赤霉烯酮(ZEN)的吸附脱除效果。在单因素试验的基础上,以活性炭添加量、吸附温度、吸附时间为自变量,ZEN脱除率为响应值,采用响应面法优化了吸附条件。结果表明:H-1活性炭(油脂专用活性炭)对ZEN的吸附能力最强;最佳吸附条件为H-1活性炭添加量2.5%、吸附温度80℃、吸附时间20 min;在最佳吸附条件下,玉米油中ZEN脱除率为(87.11±0.64)%。     

降解玉米赤霉烯酮芽孢杆菌的筛选和鉴定

从400株芽孢菌中筛选到对玉米赤霉烯酮(ZEN)有较好清除作用的两株芽孢杆菌373-2和411-1,分别与玉米赤霉烯酮(15μg/m L)共培养8 h和6 h后,将其完全清除。通过16S rDNA序列分析鉴定,373-2和411-1分别为一株新种芽孢杆菌和枯草芽孢杆菌(Bacillus subtilis)。对两株菌的玉米赤霉烯酮清除机理进行初步分析,结果表明,清除作用主要源自菌株胞外酶的降解活性。     

Co-occurrence of deoxynivalenol and zearalenone in crops marketed in Portugal

Lead, cadmium, copper, zinc and iron levels were determined in organically and conventionally produced wheat, green lentils, flower honey and eggs that are supplied on different markets in Ankara, Turkey. Their toxicological and nutritional values were compared with national and international limits and literature data. The levels of cadmium and lead in conventionally and organically produced wheat, green lentils, honey and egg were below the limit of detection (LOD), whereas the level of copper was only below LOD in honey and eggs. The levels of Zn and Cu were found to be higher in conventionally produced wheat samples than organically produced ones; whereas the level of Fe in organic products was found to be higher than the conventional products.     

Natural occurrence of aflatoxins and zearalenone in maize in Brazil. Part II

The levels of aflatoxins and zearalenone were determined in 328 samples of corn from the States of Santa Catarina, Minas Gerais, S?o Paulo, Paraná, Rio Grande do Sul and Espírito Santo by thin-layer chromatography; the samples were obtained from April 1985 through to March 1986. In 12.3% of these samples aflatoxin B1 was detected in concentrations that varied from 10 to 900 micrograms/kg (ppb); 18 samples showed levels above those tolerated by Brazilian legislation. Zearalenone was found in 4.5% of the samples analysed in concentrations that varied from 653 to 9830 micrograms/kg (ppb). The limit of detection of the method for the determination of zearalenone was 260 micrograms/kg (ppb) and the recovery was 100%.     

禾谷镰刀菌发酵液中玉米赤霉烯酮毒素的提取及纯化研究

本研究旨在通过不同萃取剂和层析柱的使用,从禾谷镰刀菌发酵液中提取、纯化玉米赤霉烯酮（zearalenone,ZEN）毒素,以期获得较高纯度的毒素。采用超高效液相色谱串联质谱（ultra-performance liquid chromatography-mass spectrometry,UPLC-MS）分析方法对其效果进行检测。研究结果表明:在单一的萃取剂中,苯的萃取效果最佳,其得率可达到73.20%;采用Daisogel反相层析柱进行纯化,得率可达到69.30%,且样品中的杂峰数目明显减少,由此证明该方法对毒素纯化效果较好。本研究对发展高纯度ZEN毒素的制备技术具有一定的指导意义和参考价值。      

Fumonisin B1, zearalenone and deoxynivalenol production by Fusarium moniliforme,F proliferatum and F graminearum in mixed cultures on irradiated maize kernels

The impact on fungal growth and mycotoxin formation of interactions between fumonisin‐producing isolates of Fusarium moniliforme and F proliferatum and a zearalenone (ZEA)‐ and deoxynivalenol (DON)‐producing isolate of F graminearum inoculated together on irradiated maize at 15 and 25 °C and at 0.98, 0.95 and 0.93 a_w was studied. The presence of F graminearum decreased the fungal populations (CFU g⁻¹ grain) of F moniliforme and F proliferatum under almost all conditions tested. In the presence of F moniliforme, CFUs of F graminearum increased significantly at 25 °C, especially at 0.93 and 0.95 a_w, while the presence of F proliferatum caused them to increase at 15 °C. The presence of F graminearum always inhibited FB₁ production, except at 25 °C and 0.98 a_w where it increased. However, the observed differences were not statistically significant. There was no effect of fungal interaction on ZEA production by F graminearum; however, when paired with F moniliforme and F proliferatum, DON production by F graminearum was significantly stimulated, especially at 0.98 a_w. © 2000 Society of Chemical Industry     

Fumonisin B1, fumonisin B2, zearalenone and ochratoxin A contamination of maize in Croatia

Mycotoxins are products of moulds that frequently contaminate maize. In this study the presence of mycotoxins fumonisin B₁ (FB₁), fumonisin B₂ (FB₂), zearalenone (ZEA) and ochratoxin A (OTA) was determined in 49 maize grain samples collected in autumn 2002. The most frequent finding was that of FB₁(100%), followed by ZEA (84%) and OTA (39%), while FB₂ was found only in three samples. The co-occurrence of two and three mycotoxins was found in 55 and 37% of samples, respectively. The concentrations (mean ± SD) of FB₁, ZEA and OTA in positive samples were 459.8 ± 310.7, 3.84 ± 6.68 and 1.47 ± 0.38 µg kg^-1, respectively, and the concentrations of FB₂ in three positive samples were 68.4, 109.2 and 3084.0 µg kg^-1. Although such low concentrations of mycotoxins are not a significant source of exposure in countries with a European diet, a few samples with extreme values indicate that thorough control is needed.