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

Yueqi Qin,Jie Zeng,Yufen Liu,Haiyan Gao,Yunfei Dai

doi:10.1590/fst.95021

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.

Highlights

Resistant starch (RS) was wrapped by insoluble dietary fiber in the small intestine of the human body, so amylase cannot contact starch, and it cannot be digested and absorbed (Englyst et al, 1992)
It may be that the replacement of wheat flour by high-content resistant potato starch type 2 (RS2) results in the dilution of the protein content in flour and the decrease of water retention
The stabilization time (Stb) decreased with increasing RS2, indicating that the dough strength decreased with increasing RS2

Summary

Introduction

Resistant starch (RS) was wrapped by insoluble dietary fiber in the small intestine of the human body, so amylase cannot contact starch, and it cannot be digested and absorbed (Englyst et al, 1992). RS1 and RS2 naturally exist in fresh foods The former is physically embedded starch, which is surrounded by a protein matrix and cell wall material to hinder the role of α-amylases. The latter is a compact crystal structure composed of amyloses, which hinders enzyme contact with the particles. Compared with traditional fiber products, it has a high gelatinization temperature, good extrusion film forming performance and low water retention performance. It can provide better texture, appearance, and taste for low-volume high-fiber products compared to traditional high-fiber products (Sajilata et al, 2006)

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Conclusion