## 3 Results  
Table 2 presents the results of the pH analysis of natural yogurts; natural yogurts with the addition of comelian cherry, bilberries, cherries, and strawberries; as well as commercial fruit yogurts. In the following sections, natural yogurts with added fruit will be referred to as diet yogurts to distinguish them from commercial plain natural yogurts (without fruit) and commercial fruit yogurts. The pH analysis of the diet yogurts showed that their pH values tended to decrease with increasing amounts of added fruit. \begin{table}
\begin{tabular}{c c c c} \hline
**Yogurt** & **pH** & **Yogurt** & **pH** \\ \hline N1 & 4.76 \(\pm\) 0.02 \({}^{\mathrm{z}}\) & DD (3) & 4.38 \(\pm\) 0.01 \({}^{\mathrm{k}}\) \\ N2 & 4.68 \(\pm\) 0.02 \({}^{\mathrm{y}}\) & DD (7) & 4.31 \(\pm\) 0.01 \({}^{\mathrm{f}\mathrm{b}}\) \\ N3 & 4.58 \(\pm\) 0.02 \({}^{\mathrm{t}\mathrm{n}\mathrm{w}}\) & DD (10) & 4.25 \(\pm\) 0.01 \({}^{\mathrm{c}}\) \\ N4 & 4.61 \(\pm\) 0.02 \({}^{\mathrm{m}\mathrm{w}}\) & DD (13) & 4.21 \(\pm\) 0.01 \({}^{\mathrm{b}}\) \\ N5 & 4.68 \(\pm\) 0.02 \({}^{\mathrm{y}}\) & DD (20) & 4.14 \(\pm\) 0.01 \({}^{\mathrm{a}}\) \\ N6 & 4.59 \(\pm\) 0.01 \({}^{\mathrm{t}\mathrm{n}\mathrm{w}}\) & & \\ N7 & 4.66 \(\pm\) 0.02 \({}^{\mathrm{y}}\) & & \\ S1 (3) & 4.41 \(\pm\) 0.02 \({}^{\mathrm{l}\mathrm{m}}\) & DS (3) & 4.55 \(\pm\) 0.01 \({}^{\mathrm{r}}\) \\ S2 (7,5) & 4.54 \(\pm\) 0.02 \({}^{\mathrm{p}\mathrm{s}}\) & DS (7) & 4.52 \(\pm\) 0.01 \({}^{\mathrm{p}\mathrm{s}}\) \\ S3 (10) & 4.35 \(\pm\) 0.01 \({}^{\mathrm{h}\mathrm{i}}\) & DS (10) & 4.49 \(\pm\) 0.01 \({}^{\mathrm{n}\mathrm{o}}\) \\ S4 (10) & 4.55 \(\pm\) 0.02 \({}^{\mathrm{m}\mathrm{f}}\) & DS (13) & 4.48 \(\pm\) 0.01 \({}^{\mathrm{n}\mathrm{o}}\) \\ S5 (13) & 4.39 \(\pm\) 0.01 \({}^{\mathrm{l}\mathrm{d}}\) & DS (20) & 4.44 \(\pm\) 0.01 \({}^{\mathrm{m}}\) \\ C1 (3) & 4.37 \(\pm\) 0.01 \({}^{\mathrm{l}\mathrm{k}}\) & DC (3) & 4.58 \(\pm\) 0.01 \({}^{\mathrm{l}\mathrm{w}}\) \\ C2 (6,7) & 4.56 \(\pm\) 0.02 \({}^{\mathrm{r}}\) & DC (7) & 4.49 \(\pm\) 0.01 \({}^{\mathrm{n}\mathrm{o}}\) \\ C3 (9) & 4.43 \(\pm\) 0.01 \({}^{\mathrm{l}\mathrm{m}}\) & DC (10) & 4.43 \(\pm\) 0.01 \({}^{\mathrm{m}}\) \\ C4 (10) & 4.34 \(\pm\) 0.02 \({}^{\mathrm{f}\mathrm{b}\mathrm{i}}\) & DC (13) & 4.31 \(\pm\) 0.01 \({}^{\mathrm{e}\mathrm{g}}\) \\ C5 (13) & 4.29 \(\pm\) 0.01 \({}^{\mathrm{d}\mathrm{f}\mathrm{d}}\) & DC (20) & 4.26 \(\pm\) 0.01 \({}^{\mathrm{d}\mathrm{f}}\) \\ B1 (3) & 4.32 \(\pm\) 0.01 \({}^{\mathrm{e}\mathrm{g}}\) & DB (3) & 4.61 \(\pm\) 0.01 \({}^{\mathrm{u}\mathrm{o}}\) \\ B2 (6) & 4.58 \(\pm\) 0.01 \({}^{\mathrm{t}\mathrm{n}\mathrm{w}}\) & DB (7) & 4.51 \(\pm\) 0.01 \({}^{\mathrm{p}\mathrm{s}}\) \\ B3 (6,3) & 4.55 \(\pm\) 0.02 \({}^{\mathrm{m}\mathrm{f}}\) & DB (10) & 4.48 \(\pm\) 0.01 \({}^{\mathrm{n}\mathrm{o}}\) \\ B4 (8) & 4.44 \(\pm\) 0.02 \({}^{\mathrm{m}\mathrm{f}}\) & DB (13) & 4.39 \(\pm\) 0.01 \({}^{\mathrm{k}}\) \\ B5 (13) & 4.31 \(\pm\) 0.01 \({}^{\mathrm{e}\mathrm{g}}\) & DB (20) & 4.29 \(\pm\) 0.01 \({}^{\mathrm{e}\mathrm{g}}\) \\ \hline \end{tabular} a–z Values are means; means with different letters are significantly different (_p_ \(\leq\) 0.05); N1–N7—natural yogurts from different manufacturers; S—commercial strawberry yogurt; C—commercial cherry yogurt; B—commercial bilyyogurt, DS—natural yogurt (N6) with added strawberry; DC—natural yogurt (N6) with added cherry; DB—natural yogurt (N6) with added bilberry; DD—natural yogurts (N6) with added correjmic cherry; values in parentheses indicate fruit content (%).  
\end{table} 
Table 2: pH values (mean \(\pm\) standard deviation) of the tested yogurts. The results of the evaluation of the antioxidant contents (ABTS, DPPH, reduction power, phenolic compounds) of natural yogurt extracts are presented in Table 3. The analyzed yogurts did not differ substantially in their ABTS and DPPH values, although statistically significant differences (\(p\leq 0.05\)) were found between individual manufacturers.