## 3 Results and Discussion
### Effect of Puree Addition on Gelation Temperature
#### 3.2.4 Sodium Alginate Solutions with Pumpkin Puree  
Figure 4B shows a comparison of the gelation curves of sodium alginate solutions at concentrations of 1(SA_1), 1.5 (SA_1.5), and 2% (SA_2) with and without the addition of pumpkin puree.  
The analysis of the obtained results of the experiments and the graphical presentation made it possible to observe that the viscosity modulus G\({}^{\prime\prime}\) of composite sodium alginate solutions with the addition of pumpkin puree, regardless of the biopolymer concentration, takes higher values throughout the test than the G\({}^{\prime\prime}\) modulus of sodium alginate solutions without the addition of pumpkin puree for the same solution concentration. Elastic modulus G\({}^{\prime}\) appears only for composite sodium alginate solutions with pumpkin puree at all solution concentrations, however, regardless of the concentration of composite sodium alginate solutions with pumpkin puree, there is no intersection of elastic modulus G\({}^{\prime}\) and viscosity modulus G\({}^{\prime\prime}\). It can be seen that the modulus of elasticity G\({}^{\prime}\) of the composite solutions of 1 (SA_1) and 2% sodium alginate (SA_2) with the addition of pumpkin puree assumes the same values of about 0.37 Pa during heating at a constant temperature of 25 \({}^{\circ}\)C, while during cooling and holding of composite solutions of sodium alginate with the addition of pumpkin puree at 0 \({}^{\circ}\)C for 5 min, the values of the modulus of elasticity G\({}^{\prime}\) for the 2% composite solution of sodium alginate (SA_2) with the addition of puree are significantly higher than the modulus of elasticity G\({}^{\prime}\) of the composite 1% sodium alginate solution (SA_1) with the addition of pumpkin puree, which the final values are, respectively, 1.4 Pa and 0.7 Pa. Viscosity moduli G\({}^{\prime\prime}\) for composite solutions of sodium alginate with puree have the highest values at a concentration of 2% (SA_2) and the lowest at a concentration of 1.5% (SA_1.5) throughout the test. It was observed that in the case of sodium alginate solutions without the addition of pumpkin puree, the viscosity modulus G\({}^{\prime\prime}\) increases with increasing concentration. Such a tendency of the viscosity modulus G\({}^{\prime\prime}\) in the case of sodium alginate solution with the addition of puree (c) unusual, the more so that the apparent viscosity of these solutions increases with the concentration increase from 0.1866 to 0.4522 Pa-s (Table 2).  
[PERSON] et al. [43] studied solutions of alginate from the leaves of _Laminarian hyperborean_ algae with the addition of a solution of a mixture of chitosan oligomers (MCO) and CaCO3. To the 10 g/L alginate solution, concentrations of 6 g/L MCO (solution A), 0.6 g/L Ca, and 3 g/L MCO (solution B), 1.2 g/L Ca (solution C) were added. The solutions were tested at a constant temperature of 20 \({}^{\circ}\)C for 300 min. Gelation was shown to be the fastest in solution A and the slowest in solution C, but the gelation time was not shown. Most likely, the alginate solutions gelled due to the addition of MCO and CaCO\({}_{3}\).