HR-MS profiling and distribution of native and modified Fusarium mycotoxins in tritordeum, wheat and barley whole grains and corresponding pearled fractions

Mycotoxins are one of the most important contaminants in cereal grains. Besides parent forms, the presence and identification of structurally modified mycotoxins is nowadays recognized as a challenging food safety-related issue and contribute to increase the human and animal exposure. The aim of this study was to follow the distribution of Fusarium toxins and their main modified forms in the pearled fractions of several grain species (i.e. tritordeum, durum and bread wheat, and barley), using high-resolution mass spectrometry technique (HR-MS). A significant decreasing trend in mycotoxins concentration was observed from the outer layer to the inner kernel, along the sequential pearling process. Among modified forms, deoxynivalenol (DON) -oligoglucosides were described for the first time in naturally infected grains, while zearalenone (ZEN) -sulphate was the only ZEN-related form detected in pearling fractions. HR-MS could be confirmed as useful technique to study and characterize modified forms of mycotoxins.