Whole wheat and white wheat flour -: the mycobiota and potential mycotoxins

Mold growth has detrimental effects on the quality of flour and may result in mycotoxin contamination The search for potential mycotoxins--almost 400 are known--is time-consuming and expensive. However, detailed knowledge about the mycobiota and especially the toxin producing fungi enables the effective search for these toxic fungal metabolites. Therefore, a whole wheat flour and a white wheat flour (type 405) were investigated for their total qualitative as well as quantitative mycobiota. Overall 51 species belonging to 14 different genera could be isolated. Total fungal counts of the whole wheat flour amounted to 1833 molds while the white wheat flour contained 1730 cfu 2 g(-1). The mycobiota of both flours was dominated by Aspergillus spp. accounting for 84% and 77.3% of the isolations, respectively. Fungi of the genus Penicillium spp. occurred only to a minor degree. 8% of the isolations in whole wheat flour and 15% in white wheat flour Aspergillus candidus was the most frequently encountered mold. Penicillium aurantiogriseum, Cladosporium cladosporioides, A. flavus, Eurotium herbariorum, P. griseofulvum, P. brevicompactum and P, viridicatum were isolated to a lesser degree. From the 3563 identified fungi 93.3% (32 species) belong to the group of toxigenic molds. (C) 2000 Academic Press.