The objective of this study was to determine, by applying fundamental principles of rheology, whether or not the structure formed by hydrated rye wedge proteins shows rheological properties typical for the wheat gluten. Grains of three rye cultivars were milled into the flour that underwent an air classification process (pneumoseparation) to release a high-protein fraction of particles sized < 15 μm. The rye grain, flour, and flour fraction of particles sized <15 μm were technologically characterized. The flour fraction of particles sized <15 μm contained almost two times more protein than the initial flour. The wedge protein preparations containing ≥90 % protein (N×6.25) were prepared from the flour fraction of particles sized <15 μm using a differential sedimentation. Using a three-stage extraction method, determined were the contents of albumins and globulins, prolamins and glutelins in the flour protein and in the flour fractions of particles sized <15 μm. Viscoelastic properties of the hydrated wedge protein preparations were studied using a shear oscillation dynamic rheology method. Mechanical spectra were determined within a frequency range from 0.001 to 200 rad/s, and analyzed using a Cole-Cole method to determine the following parameters: JN0 –viscoelastic plateau compliance; GN0 – viscoelastic plateau modulus; ω0 – characteristic frequency of loss peak; n – a parameter showing the broadness of loss peak. The mechanical spectra determined explicitly prove that a structure of gluten network has been formed within the hydrated wedge protein preparations and this structure is identical with a three-dimensional network of wheat gluten; however, its bonding density is lower.
rye, wedge protein, rye gluten, dynamic rheology, mechanical spectrum, Cole-Cole method