[Biological contamination by micromycetes in dried Boletus edulis: research of aflatoxin B1, B2 G1, G2 and ochratoxin A]. 
Aim of this survey is to identify those filamentous fungi which parasite Boletus edulis and its group and check the potential presence of secondary metabolites, specifically aflatoxin B1, total aflatoxins and ochratoxin A, in order to assess the risk to consumers' health.  Forty samples of dried Boletus edulis, collected by two food industries which distribute the product in many Italian regions, have been analysed.  The sampling plan has been conducted from November 2005 to March 2006, collecting 50 g from each commercial category of dried Boletus edulis available in the factory at the time of sampling.  All the samples have been tested by visual macroscopic and stereoscopic assays; for some samples--those referred to commercial category presumably at higher risk--we have performed cultural assays as well, typization of isolated micromycetes, extraction and quantification of aflatoxins and ochratoxin A. Mycotoxin detection has been made by HPLC, using the UNI EN 14123 and UNI EN 14132 standard methods, respectively applied to aflatoxins determination in peanuts, pistachios, figs and paprika and to ochratoxin A in barley and coffee.  Non pathogenic micromycetes, common in food products, have been frequently observed in cultural assays, while Aspergillus flavus and Aspergillus niger have been found in some samples.  However the concentration of aflatoxins was always under the quantification limit.  The survey confirm that, if the cold chain is kept throughout the process and the distribution, Boletus edulis and analogue mycetes are not a favourable substratum for the growth and the development of moulds.