Rapeseed protein as a novel ingredient of gluten-free dough: Rheological and thermal properties

Abstract

The aim of the work was to analyze the effects of rapeseed protein isolate on the rheological and thermal properties of gluten-free dough, prepared on the basis of corn and potato starches. Starch mix was replaced with rapeseed protein isolate at levels from 6 to 15%. Rheological and thermal properties of such samples were compared with the control dough. Basing on the results it was observed, that the analyzed dough samples behave as weak gels, and the values of storage G′ and loss G″ moduli significantly depend on angular frequency. The presence of rapeseed protein isolate caused a significant drop in the values of G′ and G″ which was accompanied by the increase of phase shift tangent. Additionally, such addition caused an increase of instantaneous and viscoelastic compliance in the system and a decrease of zero shear viscosity in comparison to the control sample. The samples were characterized by non-newtonian shear-thinning flow, and the application of rapeseed protein resulted in a drop of apparent viscosity under applied shear. Partial replacement of starch with rapeseed protein isolate caused a decrease of dough viscosity during pasting. No significant changes in freezable water could be observed due to the application of rapeseed protein isolate, and the values varied between 0.342 and 0.357 g/g. The thermograms obtained for individual samples revealed the presence of two peaks corresponding to the starch sources present in the system. • Rapeseed protein (RSP) was used as ingredient in gluten-free dough. • RSP modified rheological characteristics of dough. • RSP affects the pasting characteristics of starch. • RSP does not significantly affect thermal characteristics of dough.