Cereal Chem 65:208-214   |  VIEW ARTICLE

Preliminary Assessment of a Sequential Extraction Scheme for Evaluating Quality by Reversed- Phase High-Performance Liquid Chromatography and Electrophoretic Analysis of Gliadins and Glutenins.

J. E. Kruger, B. A. Marchylo, and D. Hatcher. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

After preextraction with 0.5M sodium chloride to remove albumins and globulins, the storage proteins of five wheats that vary widely in quality were extractd sequentially at 60 C with 50% 1-propanol, 50% 1- propanol containing 4% dithiothreitol (DTT), and 50% 1-propanol containing 4% DTT and 1% acetic acid. Proteins present in the various propanol extracts were analyzed by sodium dodecyl sulfate gradient polyacrylamide gel electrophoresis and reversed-phase high-performance liquid chromatography (RP- HPLC). The 50% 1-propanol extracted the bulk of the gliadins, whereas the other solvents extracted mainly glutenin polypeptides. The separation of related storage protein groupings was not clear-cut, however, as some overlap occurred between fractions. By choosing appropriate RP-HPLC conditions, it was possible to quantitate the relative amounts of omega-gliadins; alpha-, beta-, and gamma-gliadins; and high and low molecular weight glutenins in the different solvents. The amount of high molecular weight glutenins in 50% 1-propanol relative to the amount present in 50% 1-propanol containing DTT generally decreased with increasing dough strength. In addition, the ratio of high to low molecular weight glutenin subunits in 50% 1- propanol containing 4% DTT increased with increasingly stronger wheats.