Cereal Chem 69:125-131   |  VIEW ARTICLE

Relationships Between Protein Composition and Functional Properties of Wheat Flours.

R. B. Gupta, I. L. Batey, and F. MacRitchie. Copyright 1992 by the American Association of Cereal Chemists, Inc. 

Relationships between protein composition (measured by size-exclusion high-performance liquid chromatography of sonicated flour suspensions in sodium dodecyl sulfate-buffer solution) and various flour quality parameters were investigated for a set of 15 hexaploid wheat cultivars grown at six different nitrogen fertilizer levels. As the flour protein content increased, the proportion of glutenin (peak 1) remained constant, the proportion of gliadin (peak 2) increased, and the proportion of albuminglobulin (peak 3) decreased. Only the glutenin measurements (i.e., the percentage of glutenin in the protein, PG, and the percentage of glutenin in flour, FG) showed consistent relationships with different quality parameters. Flour quality parameters depended in different ways on these two measurements. Extensigraph extensibility, farinograph dough development time, and loaf volume in a long fermentation baking test correlated better with FG than with PG, accounting for 68-80% of the variation in these parameters. These correlations were higher than those with flour protein, indicating that the long-established relationships between these quality parameters and flour protein may reflect more fundamental relationships with flour glutenin. Other quality parameters (extensigraph resistance, mixograph dough development time, loaf volume in a rapid baking test) correlated better with the PG and this appeared to depend on the balance between polymeric and monomeric proteins. However, less of the variation (38-56%) could be ascribed to PG. Evidence was obtained that an additional contribution to the variation in the latter parameters originated in the glutenin subunit composition, in particular, in the balance between the high and low molecular weight subunits.