title: Sequential extraction and quantitative recovery of gliadins, glutenins, and other proteins from small samples of wheat flour.
abstract: Methods to sequentially extract and fractionate wheat flour proteins were evaluated to reliably quantify gliadins, glutenins, and albumins/globulins in single flour samples. Compositions of the resulting protein fractions were analyzed by RP-HPLC combined with SDS-PAGE. Unknown proteins were identified by mass spectrometry or N-terminal sequencing. The best separation and recovery of discrete albumin/globulin, gliadin, and glutenin fractions from the same flour sample was achieved by extraction with 0.3 M NaI in 7.5% 1-propanol followed by 2% SDS, 25 mM DTT in 25 mM TRIS, pH 8.0, and precipitation of the solubilized proteins with ammonium acetate/methanol followed by acetone. Average flour composition for the variety Butte86 was 10% albumin/globulin, 40% gliadin, and 48% glutenin. This method should be useful for determining flour composition in diverse samples and evaluating relationships between proteins and end-use functionality.
authors.affiliation: Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan Street, Albany, California 94710, USA. fmd@pw.usda.gov
authors.forename: Frances M
authors.initials: FM
authors.lastname: DuPont
authors.forename: Ronald
authors.initials: R
authors.lastname: Chan
authors.forename: Rocio
authors.initials: R
authors.lastname: Lopez
authors.forename: William H
authors.initials: WH
authors.lastname: Vensel
mesh_terms: D011232:Chemical Precipitation; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005433:Flour / Q000032:analysis*; D005903:Gliadin / Q000032:analysis / Q000302:isolation & purification*; D005983:Glutens / Q000031:analogs & derivatives* / Q000032:analysis / Q000302:isolation & purification*; D010940:Plant Proteins / Q000032:analysis / Q000302:isolation & purification*; D012995:Solubility; D014908:Triticum / Q000737:chemistry*
chemical_list: D010940:Plant Proteins; D005983:Glutens; D005903:Gliadin; C037302:glutenin