Early detection of mycotoxins: Analysis of their volatile precursors.

GIROTTI J. R., JUÁREZ M.P., MALBRAN I. AND LORI G.

Rosario

Conferencia; Primera Conferencia Latinoamericana - International Conference on Cereals and Cereal Products Quality and Safety; 2007

Bolsa de Comercio de Rosario

Early detection of mycotoxins: analysis of their volatile precursors. Girotti J. R.1, Juárez M. P.1, Malbran I.2 and Lori G.2 1 Instituto de Investigaciones Bioquímicas de La Plata (CONICET-UNLP), Facultad de Ciencias Médicas, calles 60 y 120 1° piso, CP 1900, La Plata, Argentina. mjuarez@isis.unlp.edu.ar Keywords: mycotoxin, Fusarium, solid phase microextraction (SPME), volatile organic compounds (VOC) World crop production is exposed to large losses due to the action of fungal contaminants causing significant reduction in weight, quality, and commercial value as well as affecting seed viability. Detection of toxigenic fungi in stored grains and derived products is of paramount relevance in this field because they constitute a serious health and economic issue. In Argentina, the “Fusarium head blight” is one of the major wheat diseases; the most relevant fusariotoxin in this region is deoxynivalenol (DON). Highly sensitive analytical methods to determine the identity and amount of mycotoxins present are available, however, early detection methods to detect fungal contamination have not been established yet. The objective of this study was to investigate the potential of the analysis of mycotoxin volatile precursors as a new analytical method for the early detection of fusarium contamination. Sampling of the volatile organic compounds (VOC) was performed by solid phase microextraction (SPME) technique in the head space of Fusarium cultures (Jelen et al., 1997). The performance of different SPME fibers to extract fungal VOC was assayed in different culture conditions (water content, substrate), incubation and sampling times. VOC analyses were performed by capillary gas cromatography (CGC) with flame ionization detection. The three fiber coats tested, polidimethylsiloxane (PDMS), carboxen/PDMS and PDMS/divinylbenzene (DVB), showed similar performance, although the latter reveals a larger number of VOC components. The dynamics of VOC production was studied at different time intervals. Four days after cultivation was started, detectable amounts of VOC were evident. Total time for VOC detection (sampling and analysis) is approximately 30 min. The SPME technique has a great potential to detect mycotoxin precursors, it is fast, reliable, and it does not involve solvent extraction steps.  The identity of the VOC precursors and the correlation of VOC production with mycotoxin formation should be studied.