Effect of Varying Protein Content and Glutenin‐to‐Gliadin Ratio on the Functional Properties of Wheat Dough

TLDR

The study isolated gluten, starch, lipids, and water‑soluble material from seven wheat varieties, partitioned the glutens into gliadin‑ and glutenin‑rich fractions by pH precipitation, recombined them in calculated proportions to vary protein content and glutenin‑to‑gliadin ratio, and then evaluated the resulting composite flours’ mixing, extension, and baking performance using small‑scale techniques. Dough testing revealed that higher protein content increased mixing time, peak resistance, maximum resistance to extension, extensibility, and loaf volume, while, at constant protein, a higher glutenin‑to‑gliadin ratio raised mixing time, peak resistance, maximum resistance, and loaf volume but reduced extensibility, demonstrating that protein quantity and composition independently influence dough and baking properties.

Abstract

ABSTRACT Gluten, starch, lipids, and water‐soluble material were separated from seven wheat samples with a range of protein contents and breadmaking quality. The isolated glutens were further partitioned into gliadin‐ and gluteninrich fractions using pH precipitation. Protein content and glutenin‐togliadin ratio were systematically altered by blending these fractions into the original flours in calculated amounts. Mixing properties, extension‐tester parameters, and baking performance of composite flours were determined using small‐scale techniques. Results of dough testing with blends of constant glutenin‐to‐gliadin ratio showed increases in the mixing time, mixograph peak resistance, maximum resistance to extension, extensibility, and loaf volume as the protein content increased. At constant protein content, increases in glutenin‐to‐gliadin ratio were associated with increases in mixing time, mixograph peak resistance, maximum resistance to extension, and loaf volume, and with decreases in extensibility. Thus, total protein content and glutenin‐to‐gliadin ratio independently affected dough and baking properties. The results have allowed the separation of the effects of flour protein quantity and composition on breadmaking properties.