Cereal Chem 55:230 - 243. | VIEW
Acid-Soluble Proteins of Wheat Flours. I. Effect of Delipidation on Protein Extraction.
K. H. Chung and Y. Pomeranz. Copyright 1978 by the American Association of Cereal Chemists, Inc.
Extractability and composition of proteins from flours of good and poor baking quality, and from these flours after delipidation by acetone and isopropanol, were examined. Proteins were extracted with 0.05N acetic acid from nondefatted and defatted flours. Extracts were dialyzed, lyophilized, and fractionated by gel filtration on a Sephadex G-100 column. The extracts and the fractions were characterized by starch and sodium dodecyl sulfate polyacrylamide gel electrophoresis. Both the nondefatted and the defatted poor (Chiefkan/Tenmarq) flours showed higher protein extractability than did the good flours (Shawnee). More proteins were extracted from good and poor control flours than from the corresponding defatted flours. In elution profiles from the gel column, all protein extracts showed similar retention times for the glutenin, gliadin, and water-soluble fractions. Quantitatively, the glutenins were the most variable among the gel- separated fractions in the acetic acid extracts from the flours. Whereas concentrations of gliadins were similar in all extracts, concentrations of glutenins were dependent on the flour samples and the delipidation solvent. Delipidation decreased glutenin/gliadin ratios. Glutenin/gliadin fractions showed differences between strong and weak flours and between nondefatted and defatted flours in number and intensity of electrophoretic bands.