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

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%.     

Occurrence of Fusarium T-2 and HT-2 toxins in oats from cultivar studies in Germany and degradation of the toxins during grain cleaning treatment and food processing

For the Fusarium trichothecene mycotoxins T-2 and HT-2, a combined (T-2 + HT-2) temporary tolerable daily intake (tTDI) of 0.06 µg kg^?1 body weight day^?1 was proposed at the European level in 2001 (Opinion of the Scientific Committee on Food). In the near future, maximum levels for these trichothecenes will be regulated by the European Commission as announced in EU (VO) 1881/2006. For the implementation of these maximum levels, more data on occurrence and behaviour of T-2 and HT-2 toxins in primary agricultural products as well as during cleaning treatment and food processing are needed. In the current work, we determined the T-2/HT-2 concentrations in four oat cultivars (Aragon, Dominik, Ivory, Pergamon) from ten different agricultural sites in Germany, grown in cultivar studies in 2007. The grains were de-hulled, oat meal was prepared, and bread with 20% oat meal and 80% wheat flour was baked. In the cereal-processing chain, samples were taken at various steps and subsequently analysed for their T-2/HT-2 content. We employed liquid chromatography-mass spectrometry (LC-MS) and an immunological screening method (enzyme-linked immunoabsorbant assay (ELISA)) for T-2/HT-2 determination. Detection limits were between 1 and 10 µg kg^?1 in different matrices. T-2/HT-2 concentrations determined by ELISA in oat samples from ten different agricultural sites in Germany were between 9 and 623 µg kg^?1. The median and 90th percentile were 48 and 191 µg kg^?1 T-2/HT-2, respectively. One site showed six times higher T-2/HT-2 levels than the other sites, where concentrations ranged from 322 to 623 µg kg^?1. In 80% of the samples the cultivars Pergamon and Ivory had the lowest concentration of T-2 and HT-2 toxins. Using LC-MS for T-2/HT-2 determination, cleaning of the raw material did not lead to significant reductions of T-2 and HT-2 levels, whereas de-hulling led to a reduction of over 90%. Boiling of oat meal produced from cleaned raw material to yield ‘porridge’ resulted in varying T-2/HT-2 levels in experimental replicates. No major reduction of T-2/HT-2 levels in cooked porridge was obtained. Standardized baking experiments using 20% oat meal showed that T-2 and HT-2 toxins are relatively stable during the baking process, probably due to their temperature stability.     

Characterization of phenolic compounds extracted from wheat protein fractions using high-performance liquid chromatography/liquid chromatography mass spectrometry in relation to anti-allergenic,anti-oxidant,anti-hypertension,and anti-diabetic properties

The purpose of this study was to identify novel natural bioactive phenolic compounds with anti-oxidant, anti-allergic, anti-hypertensive, and anti-diabetic properties in wheat protein fractions. Free and bound phenolic compounds were isolated from the albumin, glutelin-1, glutelin-2, prolamin, and globulin wheat protein fractions. The biological properties of the extracted phenolics were analyzed in vitro using 1,1-diphenyl-2-picryl-hydrazyl assays, enzyme-linked immunosorbent assays, angiotensin-1 converting enzyme assays, and α-amylase assays. The free and bound phenolic compounds were identified using liquid chromatography electrospray ionization tandem mass spectrometry methods. The aromatic rings in globulin were the highest in both before and after the removal of phenolic compounds (1.13 and 1.05 mg/g). The highest values of angiotensin-1 converting enzyme inhibitory and α-amylase inhibition (%) were obtained in glutelin-1 (73.17 and 96.41%, respectively) before removal phenolic compounds. The biological activity was affected by the presence or absence of phenolic compounds. Allergenicity was minimized in the presence of phenolic compounds. Correlation coefficients between wheat protein fractions and biological properties are described.