Structural Characterization and Functional Properties of Proteins from Oat Milling Fractions

The aim of this work was to study the structure and functionalities of proteins from commercial oat milling fractions. Protein isolates obtained from fine (FB), medium (MB), and low (LB) oat brans, and whole oat groat flour (WF) contained 75.0–97.1% proteins. However, the protein content of the products of 15% (15% high glucan [15HG]) and 20% (20% high glucan [20HG]) HG flours were four fold less because of their high carbohydrate contents (~75%). There was no apparent difference in molecular weights of the polypeptides (20, 35, 60, and 150 kDa) contained in these protein products. Protein profiling using mass spectrometry showed that avenin was not detected in FB and MB because of their relatively high concentrations of 11–12S globulins. Secondary structural features of the molecules and microstructure details of the gelled proteins were similar for proteins from FB, MB, LB, and WF, but different from those of 15HG and 20HG. Similarly, these differences in the structural features of proteins of the milling fractions were reflected in their water‐holding capacity and the solubility properties of the protein products.