## 3 Results and Discussion
### Rheological Analysis  
From a physicochemical point of view, the soups analysed in our study were dispersion systems [34]. The vegetable pulp constitutes a dispersed phase, whereas the soluble plant ingredients with the soluble animal proteins contained in the decoction are a con-minuous phase. The rheological properties of such systems result from the interaction be-tween these two phases. They depend on the type and amount of soluble solids in the continuous phase, as well as the volume fraction of insoluble solid particles and their size [35; 36]. The effective volume fraction of particles depends on their parameters, such as the size, morphology, hardness, and force of interactions between particles. On the one hand, intermediate sizes for particles and a considerable variety of particle sizes increase the viscosity and yield point. On the other hand, a smaller size for particles may cause a decrease in the viscoelastic moduli [37; 38; 39]. Soups are usually eaten hot. As the vegetables in the model soups were homogenised to a similar extent, the differences in the temperature patterns of the rheological determinants were determined by the density of the vegetable pulp and the density of the ingredients dissolved in water. The dynamic viscosity \(\eta\) of the model soup systems (Figure 5) showed that they were characterised by a relatively high density and, consequently, viscosity. However, the value of this parameter was significantly reduced by heating. Within the entire range of temperatures under analysis, the values of the dynamic viscosity of the cream soup with beef balls were lower than those of the cream rabbit soup. In the results from the curves showing the relationship between the viscosity and shear rate (Figure 6), the dynamic viscosity \(\eta\) of the soups decreased as the shear rate increased. The relationship between the viscosity and shear rate can be used to classify foods as Newtonian, non-Newtonian, pseudoplastic, dilatant, thixotropic, or rheopectic. This classification is useful in processing, quality control, sensory evaluation, and structural analysis. The relationship between the shear rate and dynamic viscosity of the vegetable soup with rabbit meat and the soup with rabbit meat and beef was determined at 20 \({}^{\circ}\)C and 55 \({}^{\circ}\)C on the first day after preparation and on the 21 st day of storage. The Ostwald-de Waele power model in Equation (2) was applied to describe the viscosity curves:  
\[\eta=K\gamma^{\bullet}n \tag{2}\]  
where \(\eta\) (Pas is the dynamic viscosity, \(K\) (Pas\({}^{n}\)) is the consistency factor, \(\gamma^{(1/s)}\) is the shear rate, and \(n\) (-) is the flow indicator showing the type of liquid [40]. For Newtonian fluids, n = 1; for non-Newtonian, shear-thinning fluids, 0 < n < 1; and for pseudoplastic fluids, n > 1 [41]. Table 2 shows the parameters for fitting the apparent viscosity curves \(\eta\) of the model soup systems at different shear rates shown in Figure 6 for the Ostwald-de Waele rheological model. Figure 5: Changes in the dynamic viscosity \(\eta\) of the model soup systems during heating. Values expressed as means \(\pm\) SD (n = 6). Figure 6: Changes in the dynamic viscosity \(\eta\) of the model soup systems at different shear rates. Values expressed as means \(\pm\) SD (n = 6). The fitting factors of the viscosity curves \(\eta\) showed that the model vegetable soups had a noticeable pattern of apparent viscosity, which could be characterised within the non-Newtonian behaviour of pseudoplastic flow (shear-thinning systems). The higher K values of the rabbit soup show that it was more viscous than the soup with beef balls with carrots due to the greater apparent viscosity and density. In the results from the analysis of changes in the dynamic viscosity observed during the heating of the model soups, the differences in the values of this rheological parameter may have been caused by different densities for the vegetable pulps contained in the soups.