## 3 Results and Discussion
### Dynamic Rheological Properties of Tomato Pomace Powder Suspension  
#### 3.3.1 Effect of Concentration and Temperature on Dynamic Rheological Properties  
The rheological properties of tomato products have largely been investigated in various studies. These properties are essential for a better understanding of the behavior of the product during processing, as well as for the storage and consumption of the product. By applying oscillatory tests with a small deformation amplitude, within the linear viscoelastic region, a characterization of the undisputed material structure can be achieved. It is known that tomato products are defined as pseudoplastic fluids or can be classified as weak gels that have their own compositional characteristics, with an influence on different rheological behaviors [31]. The particle properties that influence the rheology of the tomato pomace suspension include the concentration, size distribution, shape, type and surface properties, deformability and interparticle forces [31, 37]. The formulated tomato pomace suspensions with different concentrations showed differences in rheological behavior when frequency sweep tests (0.1 to 10 Hz) were applied (Figure 1). So, their dynamic rheological properties were evaluated and those concentrations could be used adequately in the product development with desired functionality. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Samples** & \(\mathbf{L^{*}}\) & \(\mathbf{a^{*}}\) & \(\mathbf{b^{*}}\) & \(\mathbf{C^{*}}\) & \(\mathbf{\Delta E}\) \\ \hline MT1 & 32.88 \(\pm\) 0.46 \({}^{\text{b}}\) & 17.37 \(\pm\) 0.72 \({}^{\text{ab}}\) & 16.9 \(\pm\) 0.62 \({}^{\text{b}}\) & 24.23 \(\pm\) 0.94 \({}^{\text{abc}}\) & - \\ MT2 & 32.45 \(\pm\) 0.40 \({}^{\text{b}}\) & 20.13 \(\pm\) 0.56 \({}^{\text{de}}\) & 19.14 \(\pm\) 0.22 \({}^{\text{cd}}\) & 27.78 \(\pm\) 0.56 \({}^{\text{de}}\) & - \\ MT3 & 32.33 \(\pm\) 0.42 \({}^{\text{b}}\) & 16.44 \(\pm\) 0.84 \({}^{\text{a}}\) & 16.5 \(\pm\) 0.55 \({}^{\text{b}}\) & 23.29 \(\pm\) 0.98 \({}^{\text{ab}}\) & - \\ CT1 & 33.04 \(\pm\) 0.75 \({}^{\text{b}}\) & 19.21 \(\pm\) 0.98 \({}^{\text{cd}}\) & 18.73 \(\pm\) 1.45 \({}^{\text{cd}}\) & 26.83 \(\pm\) 1.71 \({}^{\text{de}}\) & 1.79 \(\pm\) 0.93 \({}^{\text{c}}\) \\ CT2 & 32.03 \(\pm\) 0.70 \({}^{\text{ab}}\) & 21.05 \(\pm\) 0.53 \({}^{\text{e}}\) & 20.13 \(\pm\) 0.67 \({}^{\text{d}}\) & 29.13 \(\pm\) 0.85 \({}^{\text{e}}\) & 1.49 \(\pm\) 0.86 \({}^{\text{e}}\) \\ CT3 & 32.52 \(\pm\) 0.05 \({}^{\text{b}}\) & 18.58 \(\pm\) 0.03 \({}^{\text{bed}}\) & 17.41 \(\pm\) 0.01 \({}^{\text{bc}}\) & 25.46 \(\pm\) 0.02 \({}^{\text{bed}}\) & 1.79 \(\pm\) 0.18 \({}^{\text{c}}\) \\ HT1 & 32.40 \(\pm\) 0.05 \({}^{\text{b}}\) & 18.25 \(\pm\) 0.03 \({}^{\text{bc}}\) & 17.80 \(\pm\) 0.03 \({}^{\text{bc}}\) & 25.50 \(\pm\) 0.07 \({}^{\text{bed}}\) & 1.51 \(\pm\) 0.63 \({}^{\text{d}}\) \\ HT2 & 32.01 \(\pm\) 0.41 \({}^{\text{ab}}\) & 18.56 \(\pm\) 0.06 \({}^{\text{bed}}\) & 17.79 \(\pm\) 0.50 \({}^{\text{bc}}\) & 25.71 \(\pm\) 0.12 \({}^{\text{cd}}\) & 2.13 \(\pm\) 0.57 \({}^{\text{b}}\) \\ HT3 & 30.96 \(\pm\) 0.10 \({}^{\text{a}}\) & 16.56 \(\pm\) 0.43 \({}^{\text{a}}\) & 14.68 \(\pm\) 0.49 \({}^{\text{a}}\) & 22.13 \(\pm\) 0.33 \({}^{\text{a}}\) & 2.41 \(\pm\) 0.52 \({}^{\text{a}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Color parameters for samples with different concentrations before and after heat treatment. Figure 1: Elastic (G\({}^{\prime}\)) and viscous modulus (G\({}^{\prime\prime}\)) variations with frequency for suspension with tomato pomace powder (TP) concentration of 15 % (**a**), 20 % (**b**) and 25 % (**c**) treated at 20 \({}^{\text{c}}\)C (MT1, MT2, MT3), 60 \({}^{\text{c}}\)C (CT1, CT2, CT3) and 95 \({}^{\text{c}}\)C (HT1, HT2, HT3), respectively. The evaluated parameters, elastic modulus (G\({}^{\prime}\)) and viscous modulus (G\({}^{\prime\prime}\)) showed an evident frequency dependency, suggesting an overall mobility of the suspension inside the system.