## 3 Results and Discussion
### Analysis of Fermented Milk, Milk-Soya, and Soya Yoghurt Products
#### 3.2.2 Texture  
Figure 2a,c,e show that the hardness was significantly higher for all the fermented milk yoghurt product samples compared to yoghurt products obtained from a mixture of milk-soya or soya yoghurt products alone during all storage periods. It follows that the addition of a soya beverage significantly reduces the hardness of the resulting milk curd. The effects of storage time, type of starter, and type of beverage used to obtain milk, milk-soya, and soya yoghurt products on their hardness were noted. An increase in hardness during refrigeration was found in almost every stored sample; these changes were already statistically significant after 7 or 14 days of cold storage. The magnitude of the changes depended on the bacterial culture used to ferment the beverages; the greatest changes were observed when a propionic bacteria starter was used. These changes were not reflected in the absence of changes in pH values, as described earlier. The type of starter used, the composition of the yoghurt products, and the cold storage time also had a statistically significant effect on the adhesiveness of milk, milk-soya, and soya yoghurt products (Figure 2b,d,f). The highest adhesion values were measured in the milk-based yoghurt products (the exception was the propionic bacterium-fermented yoghurt products, which initially showed adherence at the same level as the other yoghurt samples), while the lowest values were measured in the soya-based yoghurt products. During the storage of the cow's milk yoghurt product samples and the 2:1 milk-soya mixture, a statistically significant increase in adhesiveness was noted, while in the other yoghurt samples, changes were variable and unpredictable (showing no apparent relationships). The acidifying properties of the propionic bacteria, which are weaker than those of the yoghurt starter culture, did not improve the adhesion values of the yoghurt samples. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Type of Beverage**} & **Storage Time [Days]** & **0** & **7** & **14** & **21** \\ \cline{2-6}  & \multicolumn{4}{c}{**Yoghurt Bacteria Fermented Beverages**} \\ \hline cow’s milk & 4.05 b,c \(\pm\) 0.05 & 4.01 b  \(\pm\) 0.05 & 4.02 b  \(\pm\) 0.05 & 4.01 b  \(\pm\) 0.05 & 4.01 b  \(\pm\) 0.05 & 4.01 b  \(\pm\) 0.05 \\ milk–soya (2:1) & 3.94 a \(\pm\) 0.04 & 3.93 a  \(\pm\) 0.04 & 3.92 a  \(\pm\) 0.04 & 3.92 a  \(\pm\) 0.04 & 3.92 a  \(\pm\) 0.04 \\ milk–soya (1:1) & 3.93 a  \(\pm\) 0.04 & 3.92 a  \(\pm\) 0.04 & 3.90 a  \(\pm\) 0.04 & 3.90 a  \(\pm\) 0.04 \\ milk–soya (1:2) & 3.92 a  \(\pm\) 0.04 & 3.92 a  \(\pm\) 0.04 & 3.90 a  \(\pm\) 0.04 & 3.90 a  \(\pm\) 0.04 \\ soya beverage & 4.11 c  \(\pm\) 0.05 & 4.38 f  \(\pm\) 0.04 & 4.21 d  \(\pm\) 0.05 & 4.13 c  \(\pm\) 0.05 \\ \hline \multicolumn{6}{c}{**Yoghurt and Propionic Bacteria (I:1) Fermented Beverages**} \\ \hline cow’s milk & 4.01 b  \(\pm\) 0.05 & 4.00 b  \(\pm\) 0.04 & 3.97 a  \(\pm\) 0.04 & 3.99 b  \(\pm\) 0.04 \\ milk–soya (2:1) & 3.92 a  \(\pm\) 0.05 & 3.91 a  \(\pm\) 0.05 & 3.89 a  \(\pm\) 0.04 & 3.88 a  \(\pm\) 0.04 \\ milk–soya (1:2) & 3.90 a  \(\pm\) 0.04 & 3.88 a  \(\pm\) 0.05 & 3.87 a  \(\pm\) 0.05 & 3.93 a  \(\pm\) 0.04 \\ soya beverage & 4.13 c  \(\pm\) 0.05 & 4.11 c  \(\pm\) 0.04 & 4.11 c  \(\pm\) 0.05 & 4.14 c  \(\pm\) 0.05 \\ \hline \multicolumn{6}{c}{**Propionic Bacteria Fermented Beverages**} \\ \hline cow’s milk & 4.31 f  \(\pm\) 0.05 & 4.37 f  \(\pm\) 0.05 & 4.23 e  \(\pm\) 0.05 & 4.36 f  \(\pm\) 0.05 \\ milk–soya (2:1) & 3.98 b  \(\pm\) 0.05 & 4.02 b  \(\pm\) 0.05 & 4.03 b  \(\pm\) 0.05 & 4.05 b  \(\pm\) 0.05 \\ milk–soya (1:1) & 3.96 a,b  \(\pm\) 0.05 & 4.00 b  \(\pm\) 0.04 & 3.98 b  \(\pm\) 0.04 & 4.00 b  \(\pm\) 0.05 \\ milk–soya (1:2) & 4.01 b  \(\pm\) 0.04 & 4.03 b  \(\pm\) 0.05 & 4.00 b  \(\pm\) 0.04 & 4.04 b  \(\pm\) 0.05 \\ soya beverage & 4.26 e  \(\pm\) 0.05 & 4.22 d [FONOTE:e]Footnote e: footnotemark: [ENDFOOTNOTE] \(\pm\) 0.05 & 4.29 e  \(\pm\) 0.06 & 4.25 e  \(\pm\) 0.06 \\ \hline \end{tabular}
\end{table}