Synergistic and additive effects of three high molecular weight glutenin subunit loci.: II.: Effects on wheat dough functionality and end-use quality

Understanding the relationship between basic and applied rheological parameters and the contribution of wheat flour protein content and composition in defining these parameters requires information on the roles of individual flour protein components. The high molecular weight glutenin subunit (HMW-GS) proteins are major contributors to dough strength and stability. This study focused on eight homozygous wheat lines derived from the bread wheat cvs. Olympic and Gabo with systematic deletions at each of three HMW-GS encoding gene loci, Glu-A1, Glu-B1, and Glu-D1. Flour protein levels were adjusted to a constant 9% by adding starch. Functionality of the flours was characterized by small-scale methods (2-g mixograph, microextension tester). End-use quality was evaluated by 2-g microbaking and 10-g noodle-making procedures. In this sample set, the Glu-D1 HMW-GS (5+10) made a significantly larger contribution to dough properties than HMW-GS coded by Glu-B1 (17+18), while subunit 1 coded by Glu-A1 made the smallest contribution to functionality. These differences remained after removing variations in glutenin-to-gliadin ratio. Correlations showed that both basic theological characteristics and protein size distributions of these flours were good predictors of several applied rheological and end-use quality tests.