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Hajjaji A, El Otmani M, Bouya D, Bouseta A, Mathieu F, Collin
S, Lebrihi A.
Occurrence of mycotoxins: ochratoxin A,
Vomitoxin (deoxynivalenol) and toxigenic fungi in Moroccan
wheat grains: impact of ecological factors on the growth and
ochratoxin A production.
Mol Nutr Food Res. 2006 May 5
Laboratoire d'Agro-alimentaire et Sécurité Sanitaire des
Aliments, UFR de Biochimie Appliquée et Sciences Alimentaires,
Faculté des Sciences Dhar El Mahraz, Atlas Fès, Morocco.
abhajjaji@yahoo.fr
The aim of the present work was to evaluate the contamination of
some samples, taken from Moroccan wheat grains, by ochratoxin A
(OTA), deoxynivalenol (Vomitoxin (deoxynivalenol) ) and the
associated toxigenic fungi. Moreover, we focused on the
influence of environmental factors on both the growth and OTA
production by three strains of Aspergillus. The results showed
that only few samples were contaminated by the two mycotoxins (2
samples for OTA and 7 for Vomitoxin (deoxynivalenol) ). The main
isolated fungi belong to the Aspergillus, Penicillium and
Fusarium genus; 74 Aspergillus and 28 Penicillium isolates were
tested for their ability to produce OTA. Only 2 A. alliaceus and
14 A. niger were able to synthesize OTA. However, none of
Penicillium isolates can produce this toxin under the conditions
mentioned. In respect of the effects of the temperature and
water activity (aw), the optimal conditions for the growth and
OTA production were different. While the optimal conditions of
growth for A. alliaceus and A. terreus are 30 degrees C and 0.98
aw, A. niger preferred 0.93-0.95 aw at 25 degrees C, whereas the
optimal production of OTA was observed at 30 degrees C for both
A. alliaceus and A. niger at 0.93 and 0.99 aw, respectively.
PMID: 16676377
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