## 3 Results and Discussion
### Flow Curves of Tested Film-Forming Solutions
#### 3.1.2 Soy Protein Isolate Solutions with Pumpkin Puree  
Figure 1B shows the flow curves of composite solutions of soy protein isolate at concentrations of 4 (SPI_4), 8 (SPI_8), and 12% (SPI_12) and pumpkin puree. The flow curves for the tested solution samples pass through the center of the coordinate system and \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Gelatin (PGEL)**} \\ \hline  & SS & Degrees of freedom & MS & F & \(p\)-value \\ \hline The addition of & & & & & \\ pumpkin puree & 0.024983 & 1 & 0.024983 & 99200.0 & 0.000 \\ Solution & & & & & \\ concentration & & & & & \\ The addition of & & & & & \\ pumpkin puree & 0.007332 & 1 & 0.007332 & 29114.0 & 0.000 \\ concentration & & & & & \\ \hline Statistical analysis of the correlation between the concentration of the tested hydrocolloid solutions and the apparent viscosity of & & the tested solutions & & \\ \hline Gelatin (PGEL) & & & & & \\ Soy protein isolate (SPI) & & & & & \\ Sodium alginate (SA) & & & & & \\ High-methylated apple pectin (HMAP) & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._are not straight lines, as in the case of the experimental results described above, obtained for composite solutions obtained based on gelatine with the addition of pumpkin puree. Based on the parameter R\({}^{2}\) (Table 2), the flow curves of solutions of soy protein isolate with the addition of pumpkin puree--as well as solutions without the addition of pumpkin puree and composite gelatine solutions were described using the Ostwald de Waele model (1). The course of the flow curves of the composite soy protein isolate solutions with the addition of pumpkin puree, as well as the matching parameter R\({}^{2}\), indicate that these are shear-thinning liquids with no yield point. The value of the flow index \(n\) increases with the increase in the concentration of soy protein isolate with the addition of pumpkin puree in the tested composite film-forming solutions. The obtained results show that the deviation from the Newtonian character of the flow decreases with the increase in the concentration of soy protein isolate in the mixtures with the addition of pumpkin puree, similarly as it was the case for pure soy protein isolate with concentrations in the range (4-12%) studied in previous research [27]. The apparent viscosity of composite solutions of soy protein isolate with the addition of pumpkin puree increases with the increase in the concentration of soy protein isolate in solutions and ranges from 0.0170 Pa-s for a solution with a concentration of 4% to 0.0927 Pa-s for a solution with a concentration of 12% (Table 2). In addition, composite solutions of soy protein isolate with the addition of pumpkin puree is characterized by almost ten times higher apparent viscosity than solutions of soy protein isolate without the addition of pumpkin puree at the same concentration (0.0018-0.0056 Pa-s), tested by [PERSON] et al. [27]. The greatest increase in viscosity compared to the solution of soy protein isolate without the addition of puree [27] was characterized by a composite solution with a concentration of 12% soy protein isolate. [PERSON] et al. [30] studied the rheological properties of solutions of soy protein isolate with the addition of montmorillonite. Solutions containing 0, 2.5, 5, 7.5, and 10 g of montmorillonite per 100 g of soy protein isolate were prepared. The flow curves of the soy protein isolate solutions were described using a power model, similar to the flow curves of the composite film-forming solutions based on soy protein isolate with the addition of pumpkin puree described in this study. The \(k\) parameter for the soy protein isolates solution with the addition of montmorillonite increases as the amount of montmorillonite in the solution increases.