Efeitos da radiação gama no fungo Alternaria alternata e nas micotoxinas alternariol e alternariol monometil éter em amostras de cereais artificialmente contaminadas.

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Author(s):	Raquel Braghini Total Authors: 1
Document type:	Doctoral Thesis
Press:	São Paulo.
Institution:	Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
Defense date:	2009-06-30
Examining board members:	Benedito Correa; Valter Arthur; Valderez Gambale; Carlos Pelleschi Taborda; Anna Lucia Casañas Haasis Villavicencio
Advisor:	Benedito Correa
Abstract
The present study aimed to evaluate the effects of different gamma irradiation doses on the growth of Alternaria alternata and on production of mycotoxins Alternariol (AOH) and Alternariol Monomethyl Ether (AME) in cereal samples. The results showed a significant reduction in the number of CFU/g in rice grains and sunflower seeds, which were proportional to radiation dose used. However, in corn and wheat grains was observed an increase in the number of CFU/g with the increase of gamma irradiation. The radiation doses used resulted in a reduction of AOH levels. In rice and corn grains, the production of AOH was highest in the group irradiated with 5 kGy. Similar result was obtained with relation to AME. Scanning electron microscopy made it possible to visualize structural alterations on A. alternata induced by the different g-radiation doses used. Analysis of irradiated AOH and AME toxins standards didn´t show any alteration comparing to the control group. (AU)