Resumo

Sesame seeds have a high nutritional value as a result of significant amounts of vitamins, particularly the B complex, vitamin E (powerful antioxidant) and minerals such as calcium, iron, phosphorus, potassium, magnesium, sodium, zinc and selenium. The sesame is widely used as whole grain, on human feed or manufacture of breads and biscuits. Gamma radiation is used in the food preservation to remove pathogenic and toxigenic microorganisms therefore reaches the surface and interior of food. The objectives were to verify the infection rate by Aspergillus sp. that produce aflatoxins in sesame, growth ability inhibition of these fungi after gamma radiation use, as well as the influence of radiation on the grain germination. The grains were obtained from CEASA-PE, packaged and submitted to irradiation in cobalt-60 pump, using the following doses: control (non-irradiated), 2.5, 5.0, 7.5, 10 and 12.5 kGy. For each dose, 50 grains were analyzed without previous treatment with sodium hypochlorite (0,4%). The grains were plated in a culture medium AFPA (Aspergillus flavus and A. parasiticus agar) to verify contamination by aflatoxigenic Aspergillus. There was aflatoxigenic fungi growth only in the samples which were not irradiated (88%), because the lowest dose (2.5 kGy) was sufficient to inhibit the presence of these fungi. It was observed germinated seeds in the culture medium at all doses, except in 12.5 kGy that completely inhibited germination and fungal contamination. Germination was 84% (2.5 kGy), 82% (5kGy), 62% (7.5 kGy), 8% (10 kGy). This indicates that the viability of seed for planting was conserved even being subjected to gamma irradiation, while the he lower radiation dose 2.5 kGy completely inhibited aflatoxigenic Aspergillus, adapting the sanitary quality of sesame seeds for human consumption. This study was important, since there is no literature data for the efficacy of gamma radiation in reducing contamination aflatoxigenic Aspergillus.