Hydration, microstructural characteristics and rheological properties of wheat dough enriched with zinc gluconate and resistant starch

Abstract

The aim of this work was to study the effect of zinc (Zn) gluconate-resistant potato starch type 2 (RS2) systems on hydration and rheological properties of wheat flour dough. Wheat flour, Zn with a content from 0.16 mg% to 0.32 mg% (flour basis), and enriched RS2 at levels of 10 g% to 30 g% (flour basis) were used. Hydration, rheological properties and microstructural characteristics of wheat flour dough were analyzed. The results showed that the dough stability time decreased with increasing RS2. When the RS2 content was less than 25 g%, the stability time was significantly higher than that of the control group. RS2 and Zn could improve the tensile strength and thermal stability of the dough but reduced the quality of protein and mechanical resistance of the dough. Zn could increase the hardness, adhesiveness and springiness of the dough, while RS2 had a negative effect on the springiness of the dough. The RS2-Zn system reduced the water absorption, moisture content and molecular mobility of the dough, and damaged the microstructure of the dough to varying degrees. The addition of RS2 (10 g%) and Zn (0.24 mg%) could render a dough with satisfactory rheological properties, hydration and microstructural characteristics.