RHEOLOGICAL PROPERTIES OF BISCUITS DOUGH WITH SPELT FLOUR

Abstract

Background. The analysis of modern literature sources shows that the impro­vement of existing biscuit technologies is aimed primarily at the use of various non-traditional raw materials to regulate the nutritional value and increase the stability of sponge dough during production and baking.Thus, the production of biscuits from spelt flour is one of the most promising areas of its use, as it meets the technological properties of this type of product. The aim of the work is to study the rheological properties of sponge dough from a mixture of premium wheat flour and spelt flour. Materials and methods.The object of the study is the dough for the main biscuit and with the replacement of 10, 20, 30, 40, 50 % of high-grade wheat flour (HGWF) with spelt flour (SF). The study was performed on a rotary viscometer Reotest-2 on a system of cylin­ders S, S3 at a temperature of 20 °C. Shear stress and viscosity are calculated by formulas for the corresponding values of shear rate. The whipping of the sponge dough was defined as the ratioof thevolume of the egg-sugar mixture after beating to the volume of the mixture after adding the flour mixture and stirring for 15 с(%). The stability of the sponge dough (SSD) with the addition of flour mixtures was determined as the ratio of the height of the foam after aging for 15· 60 сat a temperature of 18–20 °C to the total height of the foam column of the sample, expressed as a percentage. Results. The study found a general trend to reduce the viscosity of sponge dough for test specimens depending on the shear rate relative to control. Thus, for the studied shear deformations from 0.167 c-1 to 24.3 c-1, the viscosity of the sponge dough of the control sample decreases from 55.50to 3.26 Pa ∙ с. Replacing wheat flour with spelt flour in the amount of 10 to 50 % helps to reduce the viscosity of sponge dough from 55.50 to 1.55 Pa ∙ с. When studying the dependence of the effective viscosity of the dough for the main biscuit on the content of SF at a fixed shear rate of 24.3 c-1, two areas were identified –in the range of 0–30 and 30–50 % replacement of wheat flour for SF, for which there is a different intensity of viscosity reduction: by 38.3 and 2.4%, respectively. The increase in the stability of sponge cake dough by 3.6–43.6% in the studied samples with respect to control was due to the addition of spelt flour. Conclusion. The use of spelt flour in the composition of the main sponge cake helps to reduce the viscosity, but increases the whipping and stability of the biscuit dough, which is positive for the subsequent molding and baking.