A survey on the occurrence of Fusarium mycotoxins in Bavarian cereals from the 1987 harvest

Bavarian cereals and wheat flour from the 1987 harvest were analysed for nivalenol (NIV) and deoxynivalenol (DON) using high performance liquid chromatography (HPLC) and for T-2 toxin and zearalenone (ZEA) by enzyme-linked-immunosorbent assay (ELISA). The study included 190 field samples of wheat, barley, rye and oat with visibly damaged ears, 45 samples of wheat intended for feed production and two series of wheat flour (type 550) and whole wheat flour collected in October 1987 and June 1988. The field samples examined showed a high DON contamination of wheat (87%) with an average of 3.96 mg/kg and a maximum of 43.8 mg/kg. Mean levels between 0.33 mg/kg and 0.27 mg/kg DON could be detected in barley, rye and oat. Of the wheat samples, 58% contained ZEA with a maximum of 1.560 mg/kg. The highest levels of ZEA were detected in samples which also showed high concentrations of DON. The NIV and T-2 toxin levels were comparatively low. Thirty percent of the samples showed NIV concentrations between 0.04 mg/kg and 0.29 mg/kg and 38% contained between 0.005 and 0.60 mg/kg of T-2. In the wheat samples for feed production, only DON was detected with an average of 0.190 mg/kg and a maximum of 0.75 mg/kg. The highest DON levels (0.58 mg/kg) from October 1987 were found in the wheat flour samples which were lower than the highest DON concentration (3.24 mg/kg) detected in the samples collected during June 1988. This fact was probably due to a substantial amount of non-contaminated wheat from 1986. The toxin concentrations in the whole wheat flour were not higher than in the type 550 flour.(ABSTRACT TRUNCATED AT 250 WORDS)     

Further survey on the Fusarium mycotoxins in Korean cereals

Fifty-one samples of cereals from the 1984 harvest from Korea were analyzed for nivalenol (NIV), fusarenon-X (FX), deoxynivalenol (DON) and 3-acetyl-DON by gas chromatography (GC) utilizing a 63Ni electron capture detector (ECD), and were quantitated for zearalenone (ZEN) by high-performance liquid chromatography (HPLC) with a fluorescence detector (FD). Trichothecenes and ZEN in the positive samples were confirmed by GC-mass spectrometry (MS). Out of 51 samples, 51, 46 and 42 were positive for NIV, DON and ZEN, respectively, and one malt sample was heavily contaminated with NIV (2675 ng/g) and DON (246 ng/g), and one wheat sample was heavily contaminated with NIV (3169 ng/g). Neither FX nor 3-acetyl-DON was detected in any of the samples. The data reported here indicates that Korean cereals harvested in 1984 are simultaneously contaminated with NIV, DON and ZEN, and the incidences and levels are similar to those observed in the cereals harvested in 1983.     

A survey of the natural occurrence of Fusarium mycotoxins in cereals grown in New Zealand in 1986-1989.

Fusarium mycotoxins, principally trichothecenes, occurred commonly in grain from crops in the North Island of New Zealand, but were much less common and also at the much lower levels in grains from South Island regions. The principal contaminants were trichothecenes of the nivalenol (NIV) and deoxynivalenol (DON) types. Trichothecenes derived from scirpentriol and T-2 tetraol were not common. Moniliformin occurred very rarely, while zearalenone contamination was not uncommon, but the levels were generally low. Maize kernels were commonly contaminated by moderate levels of both NIV- and DON-type trichothecenes, with levels up to 3.6 mg/kg and 11.95 mg/kg respectively recorded. The occurrence of NIV-type trichothecenes as a general contaminant in the range of 0.3-0.8 mg/kg, and frequently as the main contaminant, is unusual.     

Fusarium mycotoxins in cereals harvested from Hungarian fields

The Fusarium mycotoxins deoxynivalenol (DON), zearalenone (ZEN) and T-2 frequently contaminate grain crops in Middle and Eastern Europe. In this survey, 116 cereal samples (maize, wheat, barley and oat) were examined for DON, ZEN and T-2 mycotoxins. Samples were collected from different areas in two Hungarian regions (North and South Transdanubia). The method of analysis was indirect competitive ELISA. Maize was the most contaminated grain regarding DON (86%), ZEN (41%) and T-2 (55%) toxins. The average results of the deoxynivalenol and zearalenone tests of maize proved to be significantly higher than those of barley or oat. DON was the most represented Fusarium mycotoxin followed by T-2 and ZEN. The examination of these mycotoxins would be necessary at a larger scale as to re-evaluate permissible levels, so increase of the monitoring programme would be advisable for the future.     

Fusarium mycotoxins and ochratoxin A in cereals and cereal products: results from the Bavarian Health and Food Safety Authority in 2004

Results from the Bavarian Health and Food Safety Authority on contamination of cereals and cereal products from the Bavarian market with the mycotoxins deoxynivalenol (DON), zearalenone (ZEA), and ochratoxin A (OTA) and of maize meal and semolina with fumonisins (FUM) in the year 2004 are presented. Contamination rates and levels of DON, ZEA, and OTA were low and did not exceed the maximum levels. However, a 92% contamination rate and high levels of FUM in maize meal and semolina were measured. Contamination levels of mycotoxins are discussed and evaluated with respect to possible health implications for consumers.     

Survey of the presence of the Fusarium mycotoxins nivalenol, deoxynivalenol and T-2 toxin in Korean cereals of the 1989 harvest.

Twenty eight samples of rice, barley, millet, corn and Indian millet harvested in Korea in 1989 were subjected to assay for contamination of nivalenol (NIV), deoxynivalenol (DON) and T-2 toxin by using gas chromatography and gas chromatography-mass spectrometry. Seven samples were found to be positive for NIV and DON in the ranges of 189-624 micrograms/kg and 168-506 micrograms/kg, respectively. Of the contaminated samples, three samples, one barley, one Indian millet and one corn sample were contaminated simultaneously with both NIV and DON. T-2 toxin was not detected in any samples.     

Natural occurrence of scirpentriol in cereals infected by Fusarium species.

Wheat, barley and oat grain samples naturally contaminated with Fusarium spp. were analysed for the presence of scirpentriol (STO). This toxin was detected in 1, 37 and 8% of 248 wheat, 32 barley and 99 oat grain samples, respectively, and the maximum concentration was 83 microg x kg(-1). Samples of wheat and oat grain with visible scab symptoms were also analysed, and STO (mean level 255 microg x kg(-1)) was detected only in oat samples infected with F. sporotrichioides and F. poae as the dominant species. We analysed 15 barley samples that were subdivided based on seed size into fractions of <2.5 and > 2.5 mm in diameter. The smaller kernels contained an average 94% of the STO in the samples (in kernel fraction > 2.5 mm 28 microg x kg(-1), <2.5 mm 297 microg x kg(-1)). In oats, STO levels were highest in the chaff, lower in the stalk's apical internode and lowest in the grain.     

Natural occurrence of Fusarium mycotoxins of the 1990 barley crop in Korea.

During the barley harvest in June 1990, there was a great deal of rainfall and high humidity in the southern part of Korea, and natural occurrence of Fusarium mycotoxins was suspected in barley samples. The samples of undergrade barley were obtained from four provinces and analysed for the presence of deoxynivalenol (DON) and nivalenol (NIV) by gas chromatography and zearalenone (ZEN) by high performance liquid chromatography. Of 37 samples, 33, 37 and 10 were positive for DON, NIV and ZEN, respectively. The husked barley contained 29-677 ng/g for DON, 114-1546 ng/g for NIV and 183-1416 ng/g for ZEN. The naked barley contained 38-645 ng/g for DON, 85-4569 ng/g for NIV and 40-1081 ng/g for ZEN. The average concentration of NIV in naked barley was higher than that in husked barley, but the average concentration of DON in husked barley was higher than that in naked barley. The survey indicates that the 1990 barley crop in Korea was heavily contaminated with Fusarium mycotoxins.     

The coexistence of the Fusarium mycotoxins nivalenol, deoxynivalenol and zearalenone in Korean cereals harvested in 1983

A survey for the occurrence of nivalenol (NIV), deoxynivalenol (DON) and zearalenone (ZEN) in Korean cereals (totalling 53 samples) harvested in 1983, showed that 96%, 72% and 57% of the samples were contaminated with NIV, DON and ZEN, respectively. Average concentrations (micrograms/kg) in unpolished barley were 546 (NIV), 117 (DON) and 110 (ZEN), and those in polished barley were 130 (NIV) and 21 (DON). The ZEN levels were below the detection limit (1 microgram/kg). Malt, wheat and rye were also heavily contaminated with these Fusarium mycotoxins. The results of this survey show that Korean cereals harvested in 1983 were significantly contaminated with NIV, DON and ZEN, and the incidence and levels, where observed, are similar to those reported in Japan.     

Effect of gamma-irradiation on the natural occurrence of Fusarium mycotoxins in wheat,flour and bread

A survey was carried out to obtain data on the occurrence of Fusarium mycotoxin in wheat and flour samples collected from local markets in Egypt and to study the influence of gamma-irradiation on controlling the occurrence of these mycotoxins in wheat, flour and bread. Deoxynivalenol (DON) was detected in five samples of wheat at levels ranging from 103 to 287 μg/kg and one sample each of flour and bread at concentrations 188 and 170 μg/kg. Zearalenone (ZEN) was detected in ten samples of wheat at levels from 28 to 42 μg/kg and four samples each of flour and bread at concentrations of 95 and 34 μg/kg, respectively. T-2 toxin was detected only in one sample each of wheat, flour and bread at concentrations of 2.9, 2.2 and 2.3 μg/kg, respectively. Gamma-irradiation at dose level of 6 kGy completely eliminated fungal flora in flour and wheat. DON, ZEN and T-2 toxin concentrations are reduced to 85, 20 and 2.0 μg/kg for wheat and to 125, 45, and 1.0 μg/kg for flour after 4 kGy exposure and a sharp drop in Fusarium toxin levels occurred at 6 kGy and was eliminated at 8 kGy. Bread prepared from 6 kGy was contaminated with Fusarium toxin at levels below 5 μg/kg. It was noticed that gamma-irradiation reduce greatly the natural occurrence of Fusarium mycotoxins in bread.     

Limited survey for the occurrence of aflatoxins in cereals and poultry feeds from Rabat, Morocco

Fifty eight (58) samples of cereals for human consumption (20 corn flour, 17 wheat flour) and poultry feeds (n=21) purchased from popular markets of Rabat in Morocco were analyzed for aflatoxins (AF) by HPLC with immunoaffinity column (IAC) clean-up and fluorimetric detection. The incidence of AF in corn, wheat flour and poultry feeds was about 80, 17.6 and 66.6% respectively. High contamination levels were found in corn and poultry feeds samples. Levels of contamination of analyzed samples with AFB1 ranged from 0.23 to 11.2, 0.03 to 0.15 and 0.05 to 5.38 ng/g for corn, wheat and poultry feeds respectively. Results showed also that the contamination of 10% of samples of corn was higher than the limit set by EU regulations for AFB1 and total AF. This is the first report on the determination of AF in corn, wheat and poultry feeds from Morocco by HPLC and IAC.     

Natural occurrence of the naphthoquinone mycotoxins,xanthomegnin, viomellein and vioxanthin in cereals and animal feldstuffs

The occurrence of xanthomegnin, viomellein and vioxanthin in commercial samples of wheat and oil seed rape, and of xanthomegnin and vioxanthin in barley, is reported for the first time. Analytical methodology for detection and confirmation of these compounds is described.     

Mycobiota and mycotoxins in Brazilian peanut kernels from sowing to harvest

The total mycobiota and the mycotoxin contamination of peanuts were analyzed in plants collected at different stages of the pod maturity sampled in Junqueirópolis, at S?o Paulo State (Brazil). The prevalent peanut mycobiota were Fusarium spp. and Aspergillus flavus, present in 26% and 17% respectively of the samples analyzed. In soil, the genus Penicillium and Fusarium were most frequently detected, and A. flavus was detected in 8% of the samples. The screening of mycotoxins indicated that aflatoxins and cyclopiazonic acid were present the highest incidence, being detected in 32% of the samples, in concentrations, respectively, from 4.20 microg/kg to 198.84 microg/kg and from 260 microg/kg to 600 microg/kg. Fumonisins were not detected by HPLC. All data were correlated with the occurrence of wind-dispersed fungi and the environmental and soil conditions. Results indicate that good management of the agricultural environment may offer a way to reduce mycotoxins and the toxigenic fungal contamination in peanuts preharvest because the pods are exposed to different environmental conditions during their formation until harvest, and the optimal conditions for mycotoxin production and fungal growth are frequently found in the crop fields.     

镰刀菌属真菌毒素的毒性研究进展

镰刀属真菌毒素是非常重要的一类真菌毒素,其种类繁多,污染率高,性质差异大,毒性也较强。本综述总结了较为常见的28种镰刀属真菌毒素(T-2毒素、HT-2毒素、蛇形毒素、新茄病镰刀菌烯醇、雪腐镰刀菌烯醇、脱氧雪腐镰刀菌烯醇、镰刀菌烯酮、玉米赤霉烯酮、伏马毒素B_1、B_2、B_3、串珠镰刀菌素、白僵菌素以及恩镰孢菌素等)近40年来体内、体外毒性研究资料,主要涵盖急性毒性、慢性毒性的致癌性、生长生殖毒性、致突变和基因毒性、免疫毒性、神经毒性、细胞毒性及血液毒性。同时对伏马毒素B_1、脱氧雪腐镰刀菌烯醇及其他几种常见毒素间的协同毒性作用进行概述。体内毒性实验研究中主要采用口服和腹腔注射的给药方式;而最常用的实验动物为鸡、小鼠、大鼠和猪。体外毒性实验研究用细胞为:鼠伤寒沙门氏菌菌株、人类巨核红细胞祖细胞以及动物肾脏上皮细胞等。对此类真菌毒素毒性的总结,可进一步加深对毒素的认识,并为食品、饲料及中药安全性方面相关的法律法规制订提供重要依据。     

A limited survey of Fusarium mycotoxins nivalenol, deoxynivalenol and zearalenone in 1984 UK harvested wheat and barley

A limited survey for the occurrence of nivalenol (NIV), deoxynivalenol (DON) and zearalenone (ZEN) in 1984 UK-grown cereals (31 samples) have been carried out using a new procedure, which is a rapid and sensitive method for Fusarium mycotoxins. NIV, DON and ZEN were detected in 17 (55%), 20 (65%) and 4 (13%) out of 31 samples, and average levels in positive samples were 101 micrograms/kg, 31 micrograms/kg and 1 microgram/kg, respectively. Additional surveys on two wheat and eight barley samples harvested in Scotland have shown that 30%, 60% and 100% of the samples were contaminated with NIV, DON and ZEN, respectively. The contents averaged 391 micrograms/kg of NIV, 39 micrograms/kg of DON and 9 micrograms/kg of ZEN. The results of this survey show that UK-grown cereals were significantly contaminated with NIV, DON and ZEN in a similar way to that observed in Japan, Korea and China. This is the first evidence of the natural occurrence of NIV in UK cereals.     

Co-occurrence of Fusarium mycotoxins in mouldy and healthy corn from Korea

A total of 71 samples consisting of 36 mouldy and 35 visibly healthy corn were collected from Kangwon province of Korea and analysed for 8-ketotrichothecenes, zearalenone (ZEA), and fumonisins, including fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3). Five 8-ketotrichothecenes, namely deoxynivalenol (DON), 15-acetyldeoxynivalenol (15-ADON), 3-acetyldeoxynivalenol (3-ADON), nivalenol (NIV), and 4-acetylnivalenol (4-ANIV), ZEA, FB1, FB2, and FB3 were detected in corn samples. DON, 15-ADON, 3-ADON, NIV, 4-ANIV, ZEA, FB1, FB2, and FB3 were detected in mouldy corn with mean values of 4.0, 0.9, 0.2, 1.7, 0.4, 0.6, 23.2, 7.5, and 6.3mug/g, respectively. Visibly healthy corn samples were contaminated with lower levels of 8-ketotrichothecenes, ZEA, and fumonisins than mouldy corn samples. However, 5 of 35 healthy corn samples analysed were contaminated with fumonisins at high levels up to 12.5mug/g for FB1, 5.4mug/g for FB2, and 0.5mug/g for FB3. This is the first report on the simultaneous occurrence of trichothecenes, ZEA, and fumonisins in corn from Korea.     

Sample preparation optimization for the simultaneous determination of mycotoxins in cereals

The efficiency of three extraction solvents and three clean-up procedures was compared for simultaneous extraction and purification of aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), and zearalenone (ZEA) from spiked cereal samples. The best recovery rates for all mycotoxins were achieved using methanol: water (80:20) as the extraction solvent and AOZ multi-functional immunoaffinity column (IAC), as clean up method with recovery values of 61–89%, while that of Oasis HLB and MycoSep 226 were 37–67% and 44–78%, respectively. Then, five variables in the IAC clean-up conditions, including primary conditioning with phosphate buffer saline (PBS) (0–10 mL) (X1), extract load up volume (10–20 mL) (X2), washing volume with PBS (10–20 mL) (X3), and eluting solution volumes with methanol (1–3 mL) (X4) and acetic acid (0–1.5 mL) (X5), were optimized for the specific purification and enrichment of the mycotoxins. Results showed that primary conditioning and PBS washing did not have a significant effect on the recovery responses of mycotoxins. Optimized conditions were selected as 0, 15, 10, 1.3, and 1.5 mL for X1–X5, respectively. The recovery rates of AFB1, AFB2, AFG1, AFG2, OTA and ZEA were within 93–104% in spiked rice, under optimal conditions. LOD and LOQ were 0.0125 and 0.05 ng/g for AFB1 and AFG1, 0.0037 and 0.015 ng/g for AFB2 and AFG2, 0.05 and 0.2 ng/g for OTA, and 0.5 and 2 ng/g for ZEA, respectively. Extraction of spiked cereal samples with methanol: water (80:20) and clean up using AOZ IAC column in optimal condition provided recovery range of 77–104% for all targeted mycotoxins.     

Epidemiology of Fusarium head blight on small-grain cereals

Fusarium head blight (FHB) is one of the most serious diseases affecting wheat and barley worldwide. It is caused by Fusarium graminearum along with F. culmorum, F. avenaceum and other related fungi. These fungi also produce several mycotoxins. Though the disease results in reduced seed quality and yield, the toxins which may accompany the disease are often a more serious problem. Pathogen inoculum is usually very abundant, however production and dispersal of inoculum are weather-sensitive processes. An abundance of colonized substrate (i.e. maize or cereal debris) in a region contributes to airborne inoculum throughout the area. Local residues beneath the cereal crop (i.e. from previous crop) may have a less obvious effect, particularly in regions where long-distance dispersal is likely due to wind conditions. The host is most susceptible to infection at anthesis and shortly thereafter. A warm, moist environment characterized by frequent precipitation or heavy dew is highly favorable to fungal growth, infection and development of disease in head tissues. As the fungus grows, it produces mycotoxins which are water-soluble and may be translocated between tissues or leeched from source tissues. Important epidemiological issues have arisen recently and include an apparent shift in prevalence of Fusarium species on infected heads in Europe toward F. graminearum; and the presence of multiple chemotypes and aggressiveness variants within a species in a region.     

Mycotoxins in breakfast cereals from the Canadian retail market: A 3-year survey

One hundred and fifty-six samples of breakfast cereals were collected from the Canadian retail marketplace over a 3-year period. The samples were analysed for the mycotoxins deoxynivalenol, nivalenol, HT-2 toxin, zearalenone, ochratoxin A, and fumonisins B₁ and B₂ to contribute to dietary exposure estimates in support of the development of Canadian guidelines for selected mycotoxins in foods. The samples included corn-, oat-, wheat- and rice-based cereals, as well as mixed-grain cereals, and were primarily from North American processors. Overall, deoxynivalenol was the most frequently detected mycotoxin —?it was detected in over 40% of all samples analysed. Fumonisins and ochratoxin A were each detected in over 30% of all samples. Zearalenone was detected in over 20% of all samples. Nivalenol and HT-2 toxin were each detected in only one sample. The survey clearly demonstrated regular occurrence of low levels of multiple mycotoxins in breakfast cereals on the Canadian market.