Effect of low ion concentrations on thiol oxidation rates, protein crosslinking, water mobility and rheology of hard wheat flour dough

Abstract

During dough making wheat flour is mixed with (tap) water containing low anion/cation levels. Research indicated that thiol oxidation kinetics and possibly the final bread product quality are affected by these low ion concentrations. Accordingly, the aim of this work was to understand the effect of (low concentrations of) different ions commonly found in tap water (Ca2+, Mg2+, Na+, Cl− and SO42−) on thiol oxidation in a model and dough system, and batter and dough properties. Solutions of selected salts (CaCl2, CaSO4, NaCl and MgCl2) and tap water promoted thiol oxidation in both model and dough systems relative to what was observed for MilliQ water. Even at these low concentrations, ions affect protein properties, impacting dough stability and rheology and potentially the associated bread quality. This work provides a better conceptual understanding of the role (different) ions play in the formation of a protein network and the rheological properties of a viscoelastic dough.