Ana Pacin

Mycotoxins in Latin America and the Caribbean

Abstract Mycotoxin contamination in Latin America and the Caribbean of a wide range of raw materials, foods and feeds were reviewed. Associated problems with their control were also detailed. The present regulation and prevention measures being carried out in the various countries are summarized.

Effect of fermentation on naturally occurring deoxynivalenol (DON) in Argentinean bread processing technology.

The stability of naturally occurring DON was evaluated during the fermentation stage of the bread-making process on a pilot scale. Two different products, French bread and Vienna bread, were prepared with naturally contaminated wheat flour (150mg kg -1) under controlled experimental conditions. Dough was fermented at 30, 40 and 50°C according to standard procedures employed in Argentinean low-technology bakeries. When the dough was fermented at 50°C, the maximum reduction was 56% for the Vienna bread, with French bread being reduced by 41%. DON reduction during bread-making occurs not only in the bakery due to thermal decomposition, but also during the fermentation step. The Argentinean traditional bread-making process might reduce DON levels during the fermentation stages if the dough is leavened at temperatures >30°C.

A survey of the natural occurrence of aflatoxins and zearalenone in Argentine field maize: 1983-1994.

A survey was carried out from 1983 to 1994 to determine the natural occurrence of aflatoxins and zearalenone in maize samples from Buenos Aires and Santa Fe provinces, Argentina. Among 2271 samples analysed, 1214 (53.5%) were contaminated with mycotoxins. Aflatoxin B1 was identified in 445 samples (19.6%), aflatoxin B2 was identified in 92 samples (4.1%) and zearalenone was identified in 676 samples (29.8%). Aflatoxin G1 was detected in only one sample and none of the samples contained detectable amounts of aflatoxin G2. Aflatoxin contamination was not detected in the 1988, 1993 and 1994 harvests and, in the other years, with the exception of 1989, the contamination levels were low. Zearalenone was found in every year.

Natural co-occurrence of fumonisins, deoxynivalenol, zearalenone and aflatoxins in field trial corn in Argentina.

Corn samples collected from the main production area in Argentina in 1995 were surveyed for the natural occurrence of Fusarium mycotoxins and aflatoxins. Fumonisins B1, B2 and B3 and zearalenone were found in all samples. A positive relationship was found between fumonisins B1, B2 and B3, B1 and B3, and B2 and B3. Deoxynivalenol and aflatoxins were not detected. Mycological survey has also revealed the predominance of Fusarium moniliforme. This is the first report on the simultaneous occurrence of fumonisins and zearalenone in corn from the main production area in Argentina.

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.

Natural occurrence of deoxynivalenol in wheat, wheat flour and bakery products in Argentina.

The objective of this study was to evaluate the natural occurrence of deoxynivalenol (DON) in wheat, wheat flour and different kinds of breads and pastries widely consumed by the population in Argentina. Of 60 wheat samples analysed, 93.3% were contaminated. The average DON contamination level over all samples was 1798 micrograms/kg, and the minimum and maximum values were 100 micrograms/kg and 9250 micrograms/kg, respectively. The wheat flour samples (61 samples) were contaminated with DON at levels ranging from 250 micrograms/kg to 9000 micrograms/kg with an average of 1309 micrograms/kg. The frequency of DON contamination over 42 samples of different bakery products was 92.8%, with levels ranging from 200 micrograms/kg to 2800 micrograms/kg with an average of 464 micrograms/kg. These results suggest a high risk for consumers of wheat products and the need to monitor final products before consumption.

Distribution of fumonisins in dry-milled corn fractions in Argentina

Corn samples and different dry-milled fractions collected from an industrial mill in Argentina were analysed. Average contaminations were FB1 1540 µg kg−1, FB2 716 µg kg−1 and FB3 152 µg kg−1 in whole corn; FB1 135 µg kg−1, FB2 39.1 µg kg−1 and FB3 10.2 µg kg−1 in corn grits; FB1 358 µg kg−1, FB2 122 µg kg−1 and FB3 45.9 µg kg-1 in ‘C’ flour; FB1 148 µg kg−1, FB2 52.5 µg kg−1 and FB3 28.3 µg kg−1 in corn meal; and FB1 4210 µg kg−1, FB2 2010 µg kg−1 and FB3 447 µg kg−1 in germ and bran together. The fumonisin contamination level was approximately three times higher in germ and bran than in whole corn, 13 times higher than in ‘C’ flour and 29 times higher than in corn meal and corn grits. Taking into account the distribution of fumonisins in commercial dry-milled corn fractions and corn meal consumption in Argentina, a theoretical whole corn level of 6640 µg kg−1 maximum of total fumonisins could be processed to obtain products considered safe for human health.

Occurrence of trichothecenes in Argentinean beer: a preliminary exposure assessment.

The presence of trichothecenes (deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, nivalenol, neosolaniol and diacetoxyscirpenol) was studied in 50 samples of Argentinean beer (nine different brands). Gas chromatography with electron capture detector was used for identification and quantification of these mycotoxins. The only mycotoxin detected was deoxynivalenol (DON). It was present in 44% of the samples, 18% were contaminated with more than 20ng/ml. Toxin levels ranged from 4 to 221ng/ml in positive samples. This is the first report on DON contamination of Argentinean beer. The estimate of probable daily intake (PDI) of DON from beer consumption in Argentina does not indicate a health hazard, but it has to be taken into account in calculations of total DON exposure in the population.

Natural occurrence of trichothecenes and zearalenone in Argentine wheat

Abstract A survey of the natural occurrence of trichothecenes and zearalenone in samples from Buenos Aires and Santa Fe provinces, Argentina, was carried out in six different crops during harvest. Among 1056 samples analysed, 524 (49.62%) were contaminated with trichothecenes and zearalenone. Deoxynivalenol was detected in all of the contaminated samples, 3-Acetyl DON in 22 samples and zearalenone in 78. In 1986, T-2 toxin (20 samples), HT-2 toxin (18), neosolaniol (16) and diacetoxyscirpenol (26) were also found. The results suggest that when meteorological conditions favour contamination it is necessary to carry out strict controls on harvest time.

Survey of Argentinean human plasma for ochratoxin A

The presence of ochratoxin A (OTA) in human blood has been reported for many countries, especially in Europe. However, so far no report exists concerning such a presence in Argentina. The aim of this study was to assess OTA concentration in human plasma in two different areas of Buenos Aires province. OTA was determined by high-performance liquid chromatography (HPLC) in 199 plasma samples from blood donors in Mar del Plata and 236 from General Rodríguez. Solid-phase extraction with Bakerbond® C-18 cartridge and a final purification with Ochraprep® immunoaffinity columns was employed. The limit of quantification of ochratoxin A was 0.019ngml−1 and the confirmation of OTA was by formation of ochratoxin A methyl ester. The results showed that 63.8% of human plasma samples from Mar del Plata and 62.3% from General Rodríguez were positive for OTA, with Winsorized means of 0.15 and 0.43ngml−1, respectively. It is important to continue the research to detect the foods responsible of the presence of OTA in plasma.