Evaluation of the mycoflora and aflatoxins from the pre-harvest to storage of peanuts: a case study doi: 10.4025/actasciagron.v36i1.16972

Abstract

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.