Resumo

Peanut is a major oilseed grown in Brazil and worldwide. The fungal invasion of seeds and grains can occur before, during or after harvesting, and these fungi can potentially produce mycotoxin. Food irradiation is a process that aims to conserve food to inhibit the presence of pathogenic microorganisms and may increase their storage time. The peanuts were obtained from CEASA-PE and growing area in Pernambuco, Brazil. The grains were collected, packaged and subjected to gamma irradiation at doses: control (non-irradiated), 6, 9, 12 and 15kGy, and evaluated with 6, 12 and 18 months. The samples were plated directly into culture medium AFPA (Aspergillus flavus and A. parasiticus agar) to search for Aspergillus that produce aflatoxins. The tests were done in triplicate, with a total of 30 grains analised for each dose and origin site. There was a complete absence of aflatoxigenic fungi growth in all irradiated samples. There was fungi growth only in non-irradiated samples, as expected. Among the aflatoxigenic Aspergillus isolated from non-irradiated samples with predominant production of Aspergillus parasiticus yellowish green fluorescence in the medium of coconut milk agar after viewing at 365nm, indicating the possible presence of aflatoxin group G. The germination of the grain was inhibited in all samples irradiated after 12 and 18 months of storage in dry. The literature said when radiation inhibits the germination of grain this indicates that they may be used for food, but its use for planting may be impaired. Gamma radiation was able to keep free of aflatoxigenic Aspergillus all the samples after 18 months of storage, confirming the results of analyzes made at 6 and 12 months and literature, who found that radiation was effective against the fungi that produce aflatoxins. This makes safer peanut irradiated for human consumption than the untreated grain.