Rheological properties of wheat dough mediated by low-sodium salt

Abstract

To clarify the correlations between dough rheology and gluten aggregation, the rheological properties of low-sodium salt dough, the molecular chain morphology, molecular weight, subunit distribution and molecular conformation of dough gluten were investigated in this paper, and these results were compared with those of NaCl and KCl alone. Results showed that hardness, extensibility and compression resistance of low-sodium salt dough were enhanced, and the doughs were more like viscoelastic solid material. Atomic force microscopy images showed that low-sodium salt induced the combination of gluten peaks to form the larger protein clusters. Size exclusion/reversed phase-high performance liquid chromatography profiles suggested that low-sodium salt increased the content of B/C-low molecular weight glutenin subunits and high molecular weight glutenin subunits by reducing the content of α- and γ-gliadin, and mediated gluten aggregation to a certain degree. Besides, fluorescence spectra demonstrated low-sodium salt changed the conformation of gluten molecules. In summary, the improvement of rheological properties of low-sodium salt dough could be caused by the aggregation of low-sodium salt and dough gluten. Correlation analysis revealed that rheological properties of low-sodium salt doughs were highly related to the content of gliadin and glutenin fractions. NaCl and KCl also presented similar effects. Among the three salts, NaCl had the most prominent effect, followed by low-sodium salt. This study provides new insights and more comprehensive theoretical basis for sodium reduction.