Alternaria toxins in Argentinean wheat, bran, and flour.

Alternaria species have been reported to infect a wide variety of vegetables, fruits, and cereal crops. Wheat is one of the most consumed cereal worldwide. A sensitive HPLC-DAD methodology was applied to quantify alternariol (AOH), alternariol methyl ether (AME) and tenuazonic acid (TeA) in 65 samples of whole wheat, bran, and flour. The extraction methodology allowed extracting the three toxins simultaneously. Limits of detection in wheat were 3.4, 4.5, and 0.5 µg kg-1 for AOH, AME and TeA, respectively. For bran, these data were 3.1, 4.5, and 12 µg kg-1 and for flour 50, 70, and 14 µg kg-1, respectively. The studied recoveries were higher than 70% and RSD was below 10%. Wheat and bran samples showed low AOH and AME contamination compared to TeA. The averages levels found for TeA in wheat, bran and flour were 19,190, 16,760, and 7360 µg kg-1, respectively.

Occurrence of alternariol and alternariol monomethyl ether in beverages from the Entre Rios Province market, Argentina.

One hundred and eighty five samples of red, white and rosé wines and different juices purchased in Entre Rios, Argentina, were analyzed for the Alternaria mycotoxins alternariol (AOH) and alternariol methyl ether (AME). White wines were analyzed after removal of alcohol by a nitrogen stream and concentrated. AOH in red wines was cleaned up by solid-phase extraction columns in series (octadecyl and amino propyl modified silica) and AME quantified directly on the sample. The juices were filtered and concentrated, and then all sample extracts were quantified by high performance liquid chromatography with photodiode array detector that allows confirmation through UV spectra. Method validation revealed a good sensitivity with adequate LOD and LOQ for AME and less sensitivity for AOH (i.e. white wine: AME 0.8 and 1.4 ng/mL, AOH 2 and 3.3 ng/mL; red wine: AME 0.1 and 0.2 ng/mL, AOH 4.5 and 7.5 ng/mL; apple juice: AME 1.7 and 2.8 ng/mL, AOH 5 and 9 ng/mL; other juices: AME 2.0 and 3.1 ng/mL, AOH 6 and 10 ng/mL). Recoveries in all cases were greater than 80 %. Four of 53 white wine samples were contaminated with AOH with a maximum level of 18 ng/mL, 6 of 56 samples of red wine had a maximum of 13 ng/mL, and 3 of 68 samples of juices had traces of AOH. AME was less frequently detected than AOH, and the LOD and LOQ for AME are smaller than for AOH. Only three samples of white wine and one of red wine were contaminated, but in only one white wine sample (AME 225 ng/mL) did the toxin level exceed the LOQ.

Alternaria alternata prevalence in cereal grains and soybean seeds from Entre Ríos, Argentina.

A mycological survey was carried out at Entre Ríos province, Argentina, on sorghum grain, maize, rice, soybean seeds and on freshly harvested and stored wheat. The isolation frequencies and relative densities of species belonging to genera Alternaria, Aspergillus, Fusarium, Penicillium and other fungi were calculated. Alternaria alternata was the major fungal species isolated from sorghum, rice, soybean seeds and on freshly harvested wheat, and a low incidence of Fusarium species was observed on the same substrates. In maize the major fungal species isolated was Fusarium verticillioides. The high incidence levels of A. alternata observed,suggest that it may be necessary to determine, among other mycotoxins, if Alternaria toxins occur in these commodities.

Alternaria alternata prevalence in cereal grains and soybean seeds from Entre Ríos, Argentina

En la provincia de Entre Ríos, Argentina se llevo a cabo un estudio micológicoen granos de sorgo, maíz, arroz y semillas de soja y en muestras de trigorecién cosechado y con un año de almacenamiento. Se calcularon lasfrecuencias de aislamiento y las densidades relativas específicas de especiespertenecientes a los géneros Alternaria, Aspergillus, Fusarium, Penicilliumy otros. Alternaria alternata, fue la especie más aislada en sorgo, arroz,soja y en el trigo recién cosechado. En los mismos sustratos se observó unaincidencia menor de especies de Fusarium. En maíz, la especie fúngicapredominante fue Fusarium verticillioides. Los altos niveles de incidencia deA. alternata observados, indicarían la necesidad de determinar, entre otrasmicotoxinas, la presencia natural de toxinas de Alternaria en estos sustratos(AU)

A mycological survey was carried out at Entre Ríos province, Argentina,on sorghum grain, maize, rice, soybean seeds and on freshly harvested andstored wheat. The isolation frequencies and relative densities of speciesbelonging to genera Alternaria, Aspergillus, Fusarium, Penicillium and otherfungi were calculated. Alternaria alternata was the major fungal speciesisolated from sorghum, rice, soybean seeds and on freshly harvested wheat,and a low incidence of Fusarium species was observed on the samesubstrates. In maize the major fungal species isolated wasFusarium verticillioides. The high incidence levels of A. alternata observed,suggest that it may be necessary to determine, among other mycotoxins,if Alternaria toxins occur in these commodities(AU)