DEPENDENCE OF PARAMETERS OF RHEOLOGICAL PROPERTIES OF BUCKWHEAT FLOUR ON CORN ZEIN

The paper deals with the effect of corn zein on the rheology of buckwheat flour dough. One of the main aspects of the study of rheological properties is the viscosity, extensibility, elasticity, water absorption capacity of dough, which depends on the concentration of added zein. Wheat flour is mainly used in baking because of the important role of the gluten protein fraction in the dough making process. Since buckwheat flour dough lacks gluten, the solution is to mimic the viscoelastic network of gluten. The aim of this study is to systematically investigate the effect of zein addition on the rheological behaviour of buckwheat dough, in order to determine the optimal proportions that can improve the dough characteristics. The addition of zein increases the viscosity in the initial (2625mPa*s) and final stages (1895mPa*s), due to its hydration and interaction with the dough components, improving its structure. However, as the temperature increases, the viscosity of the dough decreases due to the acceleration of molecular processes (starch swelling, denaturation of proteins). The most noticeable decrease occurs between 80°C and 95°C. Dough with zein content of 30%, showed a stretching similar to wheat dough. Increasing zein concentration results in a stiffer and more elastic dough structure, which has increased resistance to deformation. However, an excessively high zein content can lead to an excessively stiff dough, which will negatively affect its technological properties and the quality of the finished product. Therefore, the optimal zein concentration is selected taking into account specific requirements to the rheological characteristics of the dough and the desired properties of the final product.