Cereal Chem. 80(5):587-595The rheological properties of dough and gluten are important for enduse quality of flour but there is a lack of knowledge of the relationships between fundamental and empirical tests and how they relate to flour composition and gluten quality. Dough and gluten from six breadmaking wheat qualities were subjected to a range of rheological tests. Fundamental (small-deformation) rheological characterizations (dynamic oscillatory shear and creep recovery) were performed on gluten to avoid the nonlinear influence of the starch component, whereas large deformation tests were conducted on both dough and gluten. A number of variables from the various curves were considered and subjected to a principal component analysis (PCA) to get an overview of relationships between the various variables. The first component represented variability in protein quality, associated with elasticity and tenacity in large deformation (large positive loadings for resistance to extension and initial slope of dough and gluten extension curves recorded by the SMS/Kieffer dough and gluten extensibility rig, and the tenacity and strain hardening index of dough measured by the Dobraszczyk/Roberts dough inflation system), the elastic character of the hydrated gluten proteins (large positive loading for elastic modulus [G], large negative loadings for tan d and steady state compliance [J e 0 ]), the presence of high molecular weight glutenin subunits (HMW-GS) 5+10 vs. 2+12, and a size distribution of glutenin polymers shifted toward the high-end range. The second principal component was associated with flour protein content. Certain rheological data were influenced by protein content in addition to protein quality (area under dough extension curves and dough inflation curves [W]). The approach made it possible to bridge the gap between fundamental rheological properties, empirical measurements of physical properties, protein composition, and size distribution. The interpretation of this study gave indications of the molecular basis for differences in breadmaking performance.

The effects of protein quality, protein content, ascorbic acid, diacetyl tartaric acid ester of monoglycerides (DATEM), and their interactions on dough rheology and hearth bread properties were studied by sizeexclusion fast protein liquid chromatography, Kieffer Dough & Gluten Extensibility Rig, and small-scale baking of hearth loaves. The effect of protein content was either positive or negative on hearth loaf characteristics, form ratio, and area, depending on the amount of the largest glutenin polymers in the flour. Ascorbic acid brought out the potential in the wheat flour known as protein quality. Ascorbic acid and DATEM strengthened the doughs and improved hearth bread characteristics.

Cereal Chem. 82(3):290-301The effects of protein quality, protein content, ingredients, and baking process of flour blends on hearth loaves were studied. The flour blends varied in protein composition and content. Flours of strong protein quality produced hearth loaves with larger loaf volume, larger bread slice area, and higher form ratio (height/width) than flours of weak protein quality. The effect of protein content on hearth loaf depended on the size distribution of the proteins. Increasing protein content was associated with increased percentage of the largest glutenin polymers, and loaf volume and slice area increased significantly. The form ratio, however, remained unchanged with increasing flour protein content. Strong protein quality flours tolerated addition of whole meal flour better than weak protein quality flours. Increased amount of flour with strong protein quality improved hearth bread characteristics to a larger extent than increased protein content. Diacetyl tartaric acid ester of monoglycerides (DATEM) improved hearth bread characteristics, but the effect was small compared with the effect of protein composition.

The effect of protein quality, protein content, bran addition, diacetyl tartaric acid ester of monoglycerides (DATEM), proving time, and their interaction on hearth bread characteristics were studied by size‐exclusion fast protein liquid chromatography, Kieffer dough and gluten extensibility rig, and small‐scale baking of hearth loaves. Protein quality influenced size and shape of the hearth loaves positively. Enhanced protein content increased loaf volume and decreased the form ratio of hearth loaves. The effect of protein quality and protein content was dependent on the size‐distribution of the proteins in flour, which affected the viscoelastic properties of the dough. Doughs made from flours with strong protein quality can be proved for a longer time and thereby expand more than doughs made from weak protein quality flours. Doughs made from strong protein quality flours tolerated bran addition better than doughs made from weak protein quality flours. Doughs made from high protein content flours were more suited for hearth bread production with bran than doughs made from flours with low protein content. DATEM had small effect on dough properties and hearth loaf characteristics compared with the other factors.