Aflatoxinas são metabólitos carcinogênicos produzidos pelo Aspergillus flavus, A. parasiticus e A. nomius. No presente estudo, amostras de amendoim foram coletadas em diferentes estágios fenológicos da planta durante as safras de 2007/2008 e 2008/2009, bem como no período de armazenamento do amendoim referente à safra de 2007/2008. A micoflora e os níveis de aflatoxinas foram determinados. Os resultados demonstraram a presença de Fusarium spp., Macrophomina spp., Trichoderma spp., Aspergillus spp. e Cladosporium spp. no período de maturação (39,8; 17,9; 8,2; 2,7 e 1,7%, respectivamente) e no armazenamento (49,8; 27,8; 12,5; 8,8 e 1,0%). As aflatoxinas não foram detectadas nas amostras coletadas. Dos 25 isolados de Aspergillus spp., 24 foram produtores de aflatoxina B1 (96%), 10 de B2 (40%), 17 de G1 (68%) e 10 de G2 (40%). O isolamento de Aspergillus spp. durante o armazenamento não foi influenciado pela temperatura, umidade relativa e atividade de água (p > 0,05). A detecção de Aspergillus spp. produtores de aflatoxinas nos diferentes estágios fenológicos: ginóforo aéreo, granação (sementes), frutos maduros (vagem) e frutos secos (colheita) demonstra a importância de boas práticas agrícolas da produção ao armazenamento do amendoim no sul do Brasil.

Aflatoxins are carcinogens produced by Aspergillus flavus, A. parasiticus and A. nomius. In the present study, peanut samples were collected at different phenological stages of the plant during the 2007/2008 and 2008/2009 seasons and from stored peanuts harvested in 2007/2008. The mycoflora and aflatoxins in the peanuts were evaluated. The results showed the presence of Fusarium spp., Macrophomina spp., Trichoderma spp., Aspergillus spp. and Cladosporium spp. during the period of peanut maturation (39.8, 17.9, 8.2, 2.7 and 1.7%, respectively) and storage (49.8, 27.8, 12.5, 8.8 and 1.0%, respectively). However, aflatoxins were not detected in the samples. Of the 25 Aspergillus spp. isolates, 24 (96%) were producers of aflatoxin B1 (96%), 10 (40%) of aflatoxin B2, 17 (68%) of aflatoxin G1, and 10 (40%) of aflatoxin G2. The isolation of Aspergillus spp. during storage was not influenced by the temperature, relative humidity or water activity (p > 0.05). The detection of aflatoxin-producing Aspergillus spp. in the samples analysed at different phenological stages, aerial gynophore, pod filling (seeds), mature fruits (pod), and dry fruits (harvest), indicates the importance of good agricultural practices from the cultivation to storage of peanuts in southern Brazil.

Zearalenone, a mycotoxin produced by fungi of the genus Fusarium, including F. graminearum, triggers reproduction disorders in certain animals and hyperestrogen syndromes in humans. Current research investigates three concentrations of neem oil extract (0.1, 0.25 and 0.5%) in reducing the production of zearalenone. Neem oil extract decreased zearalenone amount in the three concentrations but highest inhibition (59.05%) occurred at 0.1%.