Abstract :
[en] Foodstuff (corn, wheat, rice, etc.) can be contaminated by several filamentous fungal species in pre or post-harvest conditions. Some of these, such as Aspergillus, Fusarium and Penicillium produce secondary metabolites, highly toxic at low concentrations to all vertebrates including humans: they can cause severe illnesses upon chronic exposure and can even lead to death after acute exposure. These non-volatile molecules are named mycotoxins and current methods to detect them, involving the use of ELISA tests or HPLC, are quite time consuming and expensive. At present there is no rapid test that does not require extensive sample preparation to detect the presence of mycotoxin directly in a production line (e.g. grain storage companies).
Therefore, the aim of this work is to identify volatile organic compounds (VOCs) markers, specific of mycotoxins’ production in foodstuff.
Using the SPME technique, we have characterized and compared the VOCs produced in vitro by non-aflatoxigenic (not producing aflatoxins) and aflatoxigenic strains of Aspergillus flavus (producing aflatoxins B1, B2 and G2, three types of mycotoxins). Preliminary analyses have shown similarities and differences between the two strains. Both of them emit VOCs as 1-octen-3-ol, 3-methylbutan-1-ol, octan-3-one, 2-methylbutanal, 3-methylbutanal, known in the literature to be specific of fungi. In particular, we have identified several strain-specific terpenes that are of interest for the development of the future molecular foot-print sensor.
The next step is to study the VOCs produced in in vivo conditions, when the fungi are growing on stored cereals; and the correlation between specific VOCs and mycotoxin production.
