Development and application of analytical methods for the determination of mycotoxins in organic and conventional wheat

Abstract

The aim of this study was to develop a multicomponent analytical method for the determination of deoxynivalenol (DON), ochratoxin A (OTA) and zearalenone (ZEN), nivalenol (NIV), 3-acetyl-DON (3-acDON), 15-acetyl-DON (15-acDON), zearalenol (ZOL) and citrinin (CIT) in wheat. It also aimed to survey the presence and amounts of DON, OTA and ZEN in Belgian conventionally and organically produced wheat grain and in wholemeal wheat flours. After solvent extraction, an anion-exchange column (SAX) was used to fix the acidic mycotoxins (OTA, CIT), whilst the neutral mycotoxins flowing through the SAX column were further purified by filtration on a MycoSep cartridge. OTA and CIT were then analysed by high-performance liquid chromatography (HPLC) using an isocratic flow and fluorescence detection, while the neutral mycotoxins were separated by a linear gradient and detected by double-mode (ultraviolet light fluorescence) detection. The average DON, ZEN and OTA recovery rates from spiked blank wheat flour were 92, 83 and 73% (RSDR = 12, 10 and 9%), respectively. Moreover, this method offered the respective detection limits of 50, 1.5 and 0.05 microg kg-1 and good agreement with reference methods and inter-laboratory comparison exercises. Organic and conventional wheat samples harvested in 2002 and 2003 in Belgium were analysed for DON, OTA and ZEN, while wholemeal wheat flour samples were taken from Belgian retail shops and analysed for OTA and DON. Conventional wheat tended to be more frequently contaminated with DON and ZEN than organic samples, the difference being more significant for ZEN in samples harvested in 2002. The mean OTA, DON and ZEA concentrations were 0.067, 675 and 75 microg kg-1 in conventional samples against 0.063, 285 and 19 microg kg-1 in organically produced wheat in 2002, respectively. Wheat samples collected in 2003 were less affected by DON and ZEN than the 2002 harvest. Organic wholemeal wheat flours were more frequently contaminated by OTA than conventional samples (p < 0.10). The opposite pattern was shown for DON, organic samples being more frequently contaminated than conventional flours (p < 0.10).

Contaminants in organically and conventionally produced winter wheat (Triticum aestivum) in Belgium

“…[Insert For mycotoxins, we confirm here, on a larger data set, some results already published (Pussemier et al 2006b). Indeed, no significant differences (p > 0.05) were obtained between mycotoxin (DON and ZEA) concentrations in conventionally and organically produced cereals even if the average levels and the calculated percentiles were systematically higher for the conventional cereals.…”

“…This is again less than what is observed in the present study (0.03 and 0.06 µg kg -1 bw for consumers of organic and conventional cereal based products, respectively). Here also it must be pointed out that contamination levels are those of unprocessed cereals and that a large part of the samples (46 out of 115) were taken during 2002, a year characterized by high levels of ZEA in harvested wheat (Pussemier et al 2006b). …”

“…In addition, it must be pointed out that 48 out of 117 samples of this study were taken during the year 2002 which was a wet year characterized by high concentrations of DON in harvested wheat (Pussemier et al 2006b). …”

Short-term effects of T-2 toxin or deoxynivalenol on lipid peroxidation and the glutathione system in common carp

“…Production of mycotoxins and analyses DON was produced by Fusarium graminearum (NRRL 5883) and T-2 toxin by Fusarium sporotrichioides (NRRL 3299) strains on corn substrate according to Fodor et al (2006). DON and 15-acetyl DON content of the feed was determined according to Pussemier et al (2006), while T-2 and HT-2 concentration was measured by HPLC after immunoaffinity cleanup (Trebstein et al, 2008).…”

Biosensors for Life Sciences

“…Several published analytical methods for the determination of ochratoxin A in maize, barley, wheat, wheat bran, wheat wholemeal, rye, wine, beer, and roasted coffee have been formally validated in collaborative studies. The methods are based on liquid chromatography (LC) with fluorescence detection, include a solid-phase extraction clean-up step with reversed-phase C18, silica gel 60, or immunoaffinity columns, and can guarantee detection of < 0.5 µg/kg (Pussemier et al, 2006). The first LC method for determining ochratoxin A in maize and barley was validated in a collaborative study with materials spiked with ochratoxin A in the range of 10-50 ng/g.…”