# Influence of Plant-Based Structuring Ingredients on Physicochemical Properties of Whey Ice Creams
## 3 Results and Discussion
### Why-Based Ice creams Aqueous Phase Analysis  
In order to study the aqueous phase of whey-based ice cream mixes, the surface tension and water activity are shown in Table 3.  
The study of surface tension in food systems allows for drawing valid conclusions regarding the physicochemical behavior of emulsifiers and stabilizers. This can provide insight into potential interactions with other ingredients in the formulation, as well as stabilizing factors. A reduction in surface tension promotes emulsion formation and formulation stability from an energetic perspective [52]. A significant decrease in surface tension was observed for the samples with \(\beta\)-glucan, decreasing from 46.422 nM/m (sample 1) to 35.801 nM/m (sample 2), and to 36.448 nM/m (sample 3). This can be attributed to the gel network formed through the interaction of \(\kappa\)-carrageenan and the (1\(\rightarrow\)3) framework with long (1\(\rightarrow\)4), (1\(\rightarrow\)6) chains of  
Figure 4: Frequency sweep of complex viscosity (**left**) and tangent of phase angle (**right**) for S.6.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **Surface Tension** & **Water Activity** \\
**No.** & **mN/m** & **a\({}_{\textbf{w}}\)** \\ \hline
1. & 46.422 \(\pm\) 0.748 ab & 0.969 \(\pm\) 0.008 bc \\
2. & 35.801 \(\pm\) 0.472 d & 0.963 \(\pm\) 0.007 bc \\
3. & 36.448 \(\pm\) 0.305 d & 0.962 \(\pm\) 0.004 c \\
4. & 39.590 \(\pm\) 0.451 c & 0.960 \(\pm\) 0.005 c \\
5. & 40.484 \(\pm\) 0.815 c & 0.963 \(\pm\) 0.006 bc \\
6. & 46.609 \(\pm\) 0.541 ab & 0.969 \(\pm\) 0.005 ab \\
7. & 46.085 \(\pm\) 0.885 ab & 0.968 \(\pm\) 0.007 b \\
8. & 47.228 \(\pm\) 0.992 ab & 0.987 \(\pm\) 0.003 a \\
9. & 46.998 \(\pm\) 1.087 ab & 0.985 \(\pm\) 0.007 a \\ \hline \hline \end{tabular}
\end{table}
Table 3: Surface tension and water activity of whey-based ice cream mixes.  
\(\beta\)-glucan. In this study, 0.5% of yeast \(\beta\)-glucan, and 0.75% of oat \(\beta\)-glucan were used, which was sufficient to establish a gel network with relative strength. According to [PERSON] et al. [53], the addition of 0.8% yeast-derived \(\beta\)-glucan can lead to a reduction in the duration of yogurt mix fermentation, resulting in the formation of a robust gel network. Thus, the content used in this study was suitable to form a gel network with relative strength. [PERSON] and [PERSON] [54] have highlighted the low solubility of \(\beta\)-glucan from baker's yeast due to its linear structure, potentially leading to complex formation with proteins. Meanwhile, [PERSON] et al. [55] emphasized the effectiveness of \(\beta\)-glucans from brewer's yeast as thickeners, water-retaining agents, and stabilizers in food technology. However, there is a scientific novelty in the application of \(\beta\)-glucans from baker's yeast _Saccharomyces cerevisiae_ in whey ice cream technology. Another notable observation is the significant reduction in surface tension in the mix containing 0.4% Vianoks C45 + 3% WPC + 10% vegetable pure from table beets, in contrast to the samples containing broccoli or zucchini puree (samples 6-9), which exhibited surface tension values at or slightly above the level of the control ice cream. These differences may be attributed to both the distinct pectin content in vegetable raw materials, particularly soluble pectin, and the presence of anthocyanins, capable of forming complexes with whey proteins, thereby influencing color and rheological characteristics [56]. Regarding the water activity, the highest values were found for samples 8 and 9, which were also characterized by a tangent of the phase angle close to 1 across the entire frequency range. This means that these samples did not show a gel-like behavior, and therefore, the water was not strongly bound. For other samples, some structurization of the material was noted as the tangent of the phase angle decreased with increasing frequency (Figure 2e,f and Figure 4), which may explain their lower water activities.