MALDI-TOF mass spectrometry of hordeins: rapid approach for identification of malting barley varieties

A procedure for identification of malting barley varieties using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of ethanol-soluble barley proteins (hordeins) is described. The hordeins were first extracted from milled barley grains by several extraction protocols (using different extraction agents and conditions). Hordein extracts were then analyzed directly via MALDI-TOF MS without any preliminary purification or separation step, and the protein profiles of analyzed hordein extracts were compared in order to find out the most suitable extraction procedure for mass spectrometric analysis. The optimized procedure was successfully applied to identification of 13 malting barley varieties. Our results revealed that the proposed mass spectrometry-based approach provides characteristic mass patterns of extracted hordeins, which can be advantageously used for barley variety identification. Copyright (C) 2009 John Wiley & Sons, Ltd.