Authors
Title
Abstract
The research comprised the fractional composition of proteins in the flour from einkorn grain (Triticum monococcum L. ssp. monococcum) of the Svenskaja, Terzino, and Tifi cultivars, as well as in the flour from common wheat (T. aestivum L. ssp. aestivum) of the Figura cultivar; the rheological properties of gluten, washed-out from the flours studied, were also analyzed. The fractional composition of proteins in einkorn and wheat flours was determined using a three-step extraction method. The gluten proteins consisted of 79.9 (Terzino) to 81 % (Tifi) of the protein system in the flour from einkorn grain and proved to have the ability to fully dispergate. Determined were the mechanical spectra of gluten within the frequency range from 0.001 to 200 rad/s, at a temperature of 20 °C. Those mechanical spectra were described using Cole-Cole equations; the following was computed: GN0 – viscoelastic plateau modulus; JN0 – plateau compliance; ω0 – characteristic frequency; n parameter. Compared to the wheat gluten, the einkorn gluten showed a higher contribution of its viscous properties to the overall viscoelasticity. The gluten obtained from the individual einkorn cultivars significantly differed in the contribution range of its viscous and elastic properties to the overall viscoelasticity; this was proved by the differences in the values of δ phase angle in the analyzed range of the oscillation frequency. The differences in GN0 , JN0 , ω0, and n values of gluten found in three einkorn cultivars studied indicate a strong differentiation in their gluten matrix network density, and the weakest network structure shows gluten of Tifi einkorn cultivar. During the oscillatory shearing, in the range of the lowest oscillation frequencies analyzed, a certain lability of the network structure of the einkorn gluten is displayed.
Keywords
einkorn, common wheat, gluten, rheology, Cole-Cole equations, viscoelasticity, prolamins, glutenins