Resumo

PRADO, Guilherme et al. Irradiation effect on mycoflora of medicinal plants. Ciênc. agrotec. [online]. 2009, vol.33, n.5, pp. 1372-1378. ISSN 1413-7054.  http://dx.doi.org/10.1590/S1413-70542009000500025.

The increasing consumption of natural products has brought about problems related to public health due to the risk of fungi contamination and the considerable possibility of mycotoxin presence. The aim of this work was to identify the fungi species with mycotoxigenic potential and to evaluate the effect of gamma irradiation (⁶⁰Co) on killing the natural fungi microbiota of five medicinal plants: artichoke (Cynara scolymus L.), boldo (Peumusboldus Molina), chamomile (Matricaria recutita L.), burhead (Echinodorusgrandiflorus Micheli), and senna (Cassia acutifolia Delile). The qualification of filamentous fungi and yeast was carried out utilizing the Technique of Serial Dilutions on DRBC medium. Eight isolates of Aspergillus flavus were identified onchamomile, two (25%) beingproducers of aflatoxins B₁ and B₂ as well as five isolates of Aspergillus ochraceus, two (40%) being producers of ocratoxin. On artichoke, one isolate of Aspergillus ostianus was identified as ocratoxin A producer. A reduction on the total counting of fungi was observed in boldo with irradiation higher than 3 kGy, and in both burhead and senna with irradiation higher than 5 kGy. The initial counting on artichoke of 5.0 x 10⁶ CFU/g experienced a reduction to 3.5 x 10² with doses of 10 kGy. With this same dose the fungi counting on chamomile was reduced from 3.0 x 10⁵ CFU/g to 2.2 x 10³ CFU/g.

Palavras-chave : Cobalt 60; toxigenic fungi; contamination; medicinal plants.