30 Use of flow field-flow fractionation and mass spectrometry for characterization of wheat proteins.

K. R. PRESTON (1) and W. Ens (2). (1) Canadian Grain Commission, Winnipeg, MB, Canada; (2) Department of Physics, University of Manitoba, Winnipeg, MB, Canada.

Flow field-flow fractionation (flow FFF) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI/MS) are techniques that have recently proven useful for the characterization of wheat proteins. Conventional stopped-flow FFF, which has an exclusion limit in the micron range, has been used to fractionate and determine the size of very large wheat polymeric proteins and/or complexes. The recent introduction of automated frit inlet/frit outlet flow FFF with buffer recycling has improved sensitivity and allowed the accurate quantification of the size distribution of these proteins. MALDI/MS has been used to determine the subunit composition and molecular weight of gliadin, low molecular weight glutenins and high molecular weight glutenins. Recent studies suggest that improvements in resolution and handling of samples may allow this technique to be used for identification of wheat class and/or variety using gliadin patterns.