Effect of the Water Soluble Fraction on the Viscoelasticity of Wheat Gluten

Abstract

The effects of the water soluble fraction and the dough mixing procedure on the formation of a viscoelasic gluten mass were examined by means of a reconstitution study. Gluten and the water soluble fraction were prepared by two methods, water extraction and dough mixing, and then lyophilized. With the dough mixing method, water soluble components, especially gliadin, were incorporated into the gluten mass. On the other hand, gluten prepared by water extraction was poor in gliadin and so, being elastic and less extensible, differing from gluten obtained from dough.
Gluten was prepared from reconstituted dough, in which lyophilized gluten, lyophilized water soluble fraction and starch were mixed in the original ratio. The reconstituted gluten with gluten obtained by dough mixing had the same rheological properties as those of gluten from flour. The same results were obtained when gliadin was used instead of the water soluble fraction. On the other hand, despite the same ratio of gliadin and glutenin, the reconstituted gluten with gluten obtained by water extraction was elastic and less extensible. These lines of evidence suggested that for the formation of a viscoelastic mass, gliadin must be well mixed with glutenin to form a homogeneous gluten network.
In this paper, we also found that gliadin was one of the factors causing breakdown and this phenomenon was related to the formation of a viscoelastic mass during dough mixing.