44G-21 |
Analysis of moulds and mycotoxins in pre-harvest and pos-harvest maize - Rio Grande do Sul, Brazil. |
G. Hermanns1, I. B. NOLL1, E. A. Trindade2, E. B. Furlong3, H. Bartels4, R. Martins5, and E. Viola5. (1) Food Science and Technology Institute, Federal University of Rio Grande do Sul, Rua 24 de maio, 85/7, Porto Alegre, 90050-180, Brazil, (2) Food Science and Technology Institute, Federal Univesrity of Rio Grande do Sul, Box 15090, Porto Alegre, 91501-970, (3) Chemistry Department - Food Science, Federal University of Rio Grande, Rua Eng. Alfredo Huch, 475, Rio Grande, 96201-900, Brazil, (4) EMATER/RS - Agricultural Department, Government of the State of Rio Grande do Sul/Brazil, Rua Botafogo, 1051, Porto Alegre, 90150-053, Brazil, (5) EMATER/RS - Agricultural Department, Government of the State of Rio Grande do Sul, Rua Botafogo, 1051, Porto Alegre, 90150-053, Brazil Maize (Zea mays L.) is one of the most commonly cultivated grain in Brazil. The high occurrence and frequency of mycotoxins contamination occurs due to field and storage toxigenic mould infestation and climate variation. In Rio Grande do Sul, the southern state in Brazil, the average relative humidity rate is larger than 70% and temperature changes are very common, mainly in winter. The south tip of Brazil is therefore, humid during cold and warm months. These factors influence the development of field moulds as Fusarium spp and storage moulds as Aspergillus spp and Penicillium spp. These toxigenic moulds are responsible for the production of aflatoxins, ochratoxins, zearalenone and fumonisins. These mycotoxins represent a potential risk to human and animal health safety. The occurrence of mycotoxins in final products can be prevented by good manufacturing practices. Therefore, the purpose of this study is to monitoring all stages of maize production, from the field to final consumer, through the analysis of the critical control points. Aflatoxins, ochratoxin A and zearalenone were analyzed by a multitoxin thin layer chromatographic method that involves extraction with methanol-4% KCl (9:1), clean-up with ammonium sulfate solution and partition to chloroform. Positive samples were confirmed by chemical derivatization Aflatoxins B1, B2, G1 e G2 were found in 17,37% of the 213 final corn samples in concentrations that varied from 3,18 to 25,6 ug/kg, two samples exceeding the limit established by Brazilian legislation (20 u/kg B1, B2, G1 e G2). Ochratoxin A was responsible for 8% of contamination, with levels ranging 2,34 to 8,17 ug/kg and zearalenone was found in aproximately 3 % of the samples. The results of this work are of significance, considering that 20 % of harvested maize in Rio Grande do Sul are lost due to fungal and mycotoxin contamination.
Session 44G, Toxicology & Safety Evaluation
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