## 2 Results and Discussion
### Phenolics, Antioxidant Activity and Color of Citrus Fiber/Blackberry Gels
As was observed after preparation, gels with trehalose had higher antioxidant activity than sucrose gels. Antioxidant activity evaluated with the FRAP method also revealed that after preparation, gels with trehalose had higher antioxidant activity than those prepared with sucrose. Amount of added trehalose had no effect on antioxidant activity, while gels with 20% of sucrose had a higher value than the ones with 10% of sucrose. After storage, values of antioxidant activity decreased, and the trend observed after preparation remained equal. CUPRAC antioxidant activity revealed that there was no difference between gels with trehalose, and these samples had higher values of antioxidant activity than those prepared with sucrose. After storage, antioxidant activity decreased, but the same trend as after preparation was retained, as was the case with the FRAP method. To explain the occurrence of the higher post-storage antioxidant activity results obtained by the ABTS assay, the nature of ABTS and DPPH radicals were compared. DPPH reacts more slowly with electron and hydrogen donors, which can lead to underestimation of fast reactors. ABTS also reacts with electron and hydrogen donors, but DPPH is much more selective in its reaction with hydrogen donors. ABTS can overestimate the antioxidant activity because it reacts with any hydroxylated aromatics regardless of the real antioxidant potential. Flavonoids that  
\begin{table} \begin{tabular}{c c c c c c c} \hline \hline
**Samples** & **TPC** & **PAC** & **DPPH** & **ABTS** & **FRAP** & **CUPRAC** \\ \hline \multicolumn{7}{c}{After preparation} \\ \hline
10\%\_S & 4.652 \(\pm\) 0.005 \({}^{\text{c}}\) & 120.33 \(\pm\) 0.98 \({}^{\text{d}}\) & 197.92 \(\pm\) 1.23 \({}^{\text{d}}\) & 1.054 \(\pm\) 0.038 \({}^{\text{d}}\) & 245.71 \(\pm\) 2.94 \({}^{\text{c}}\) & 148.76 \(\pm\) 0.98 \({}^{\text{d}}\) \\ \hline
20\%\_S & 4.937 \(\pm\) 0.056 \({}^{\text{b}}\) & 129.78 \(\pm\) 0.45 \({}^{\text{c}}\) & 233.91 \(\pm\) 1.47 \({}^{\text{a}}\) & 1.114 \(\pm\) 0.067 \({}^{\text{d}}\) & 253.70 \(\pm\) 0.41 \({}^{\text{b}}\) & 153.71 \(\pm\) 1.21 \({}^{\text{a}}\) \\ \hline
10\%\_T & 4.946 \(\pm\) 0.045 \({}^{\text{b}}\) & 140.46 \(\pm\) 1.11 \({}^{\text{b}}\) & 204.13 \(\pm\) 1.21 \({}^{\text{c}}\) & 1.478 \(\pm\) 0.044 \({}^{\text{b}}\) & 292.29 \(\pm\) 1.10 \({}^{\text{a}}\) & 170.16 \(\pm\) 1.05 \({}^{\text{b}}\) \\ \hline
20\%\_T & 5.233 \(\pm\) 0.044 \({}^{\text{a}}\) & 156.85 \(\pm\) 1.34 \({}^{\text{a}}\) & 216.55 \(\pm\) 1.57 \({}^{\text{b}}\) & 1.526 \(\pm\) 0.099 \({}^{\text{b}}\) & 291.05 \(\pm\) 0.96 \({}^{\text{a}}\) & 170.61 \(\pm\) 1.11 \({}^{\text{b}}\) \\ \hline \multicolumn{7}{c}{After storage} \\ \hline
10\%\_S & 4.133 \(\pm\) 0.044 \({}^{\text{f}}\) & 88.45 \(\pm\) 0.20 \({}^{\text{f}}\) & 160.03 \(\pm\) 1.37 \({}^{\text{f}}\) & 1.248 \(\pm\) 0.011 \({}^{\text{c}}\) & 206.69 \(\pm\) 1.65 \({}^{\text{e}}\) & 134.24 \(\pm\) 0.97 \({}^{\text{f}}\) \\ \hline
20\%\_S & 4.504 \(\pm\) 0.031 \({}^{\text{d}}\) & 105.56 \(\pm\) 0.77 \({}^{\text{e}}\) & 164.98 \(\pm\) 1.41 \({}^{\text{f}}\) & 1.214 \(\pm\) 0.038 \({}^{\text{c}}\) & 226.42 \(\pm\) 3.34 \({}^{\text{d}}\) & 142.40 \(\pm\) 1.99 \({}^{\text{e}}\) \\ \hline
10\%\_T & 4.354 \(\pm\) 0.062 \({}^{\text{e}}\) & 120.26 \(\pm\) 1.73 \({}^{\text{d}}\) & 181.45 \(\pm\) 1.47 \({}^{\text{e}}\) & 1.502 \(\pm\) 0.018 \({}^{\text{b}}\) & 254.42 \(\pm\) 1.87 \({}^{\text{b}}\) & 166.80 \(\pm\) 1.17 \({}^{\text{c}}\) \\ \hline
20\%\_T & 4.558 \(\pm\) 0.054 \({}^{\text{d}}\) & 121.72 \(\pm\) 1.56 \({}^{\text{d}}\) & 184.19 \(\pm\) 1.61 \({}^{\text{e}}\) & 1.654 \(\pm\) 0.077 \({}^{\text{a}}\) & 256.49 \(\pm\) 1.52 \({}^{\text{b}}\) & 167.42 \(\pm\) 1.01 \({}^{\text{c}}\) \\ \hline \hline \end{tabular}