Study of the natural occurrence of T-2 and HT-2 toxins and their glucosyl derivatives from field barley to malt by high-resolution Orbitrap mass spectrometry

Abstract

This paper reports a new method for the determination of T-2 and HT-2 toxins and their glucosylated derivatives in cereals, and some survey data aimed at obtaining more comprehensive information on the co-occurrence of T-2 and HT-2 toxins and their glucosylated derivatives in naturally contaminated cereal samples. For these purposes, barley samples originating from a Northern Italian area were analysed by LC-HRMS for the presence of T-2, HT-2 and relevant glucosyl derivatives. Quantitative analysis of T-2 and HT-2 glucosides was performed for the first time using a recently made available standard of T-2 glucoside. The glucosyl derivative of HT-2 was detected at levels up to 163 µg kg(-1) in 17 of the 18 analysed unprocessed barley grains, whereas the monoglucosyl derivative of T-2 toxin was detected in only a few samples and at low µg kg(-1) levels. The ratio between glucosylated toxins (sum of T-2 and HT-2 glucosides) and native toxins (sum of T-2 and HT-2) ranged from 2% to 283%. Moreover, taking advantage of the possibility of retrospective analysis of full-scan HRMS chromatograms, samples were also screened for the presence of other type-A trichothecenes, namely neosolaniol, diacetoxyscirpenol and their monoglucosyl derivatives, which were detected at trace levels. A subset of nine different samples was subjected to micro-maltation in order to carry out a preliminary investigation on the fate of T-2, HT-2 and relevant glucosides along the malting process. Mycotoxin reduction from cleaned barley to malt was observed at rates ranging from 4% to 87%.

Changes in the Fusarium Head Blight Complex of Malting Barley in a Three-Year Field Experiment in Italy

“…This is also supported by a recent investigation performed on malting barley in Italy, during which a higher HT-2 toxin content with respect to T-2 toxin was detected [24]. In addition, the presence of glucosyl derivative of HT-2 toxin could have been present as it was detected in malting barley kernels cultivated in Nothern Italy [48]. …”

“…In fact, DON incidence seems to be stable over the years in most of the countries, with concentrations, which are generally below the EU legal limits for unprocessed barley [10]. Conversely, the incidence of T-2 and HT-2 toxins seems to increase over the years [48]. In fact, after oats, barley resulted to be one of the most contaminated cereals with HT-2 and T-2 toxins [50].…”

Advanced LC–MS-based methods to study the co-occurrence and metabolization of multiple mycotoxins in cereals and cereal-based food

“…The increasing interest in the use of HRMS is evident from the number of articles that have been published [51,83,84]. The presence of glycosylated metabolites of HT2 and T2 in wheat, oat, and barley was confirmed by Veprikova et al [83].…”

“…Moreover, HT2 diglucoside and T2 diglucoside in barley were found for the first time [83]. The occurrence of HT2, T2, and their glycosides in cereals and their fate during malting were studied [51]. Because of the use of an HPLCOrbitrap system (HRMS), a retrospective analysis of the fullscan HRMS chromatograms was possible, and presence of neosolaniol, DAS, and their monoglucosides was also successfully evaluated.…”

“…Furthermore, also traces of neosolaniol glucoside and DAS glucoside were found. The preliminary investigation on the fate of HT2 and T2 and their glucosylated forms during malting revealed a general mycotoxin reduction from cleaned barley to malt [51].…”