## 2 Results and Discussion
### Phenolics, Antioxidant Activity and Color of Citrus Fiber/Blackberry Gels
Before storage, gels with 10% trehalose had the highest C* value (14.18), and gels with 20% trehalose had the lowest (12.76). During storage, there was a decrease in C* value in all samples. Highest and lowest C* values after storage were observed in the same samples as after preparation. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Samples** & **L*** & **a*** & **b*** & **\(\Delta\)E** & \({}^{\circ}\)**h** & **C*** \\ \hline \multicolumn{5}{c}{After preparation} \\ \hline
10\%\_S & 35.79 \(\pm\) 0.03 e & 12.90 \(\pm\) 0.01 b & 4.31 \(\pm\) 0.02 e & 18.46 \(\pm\) 0.09 d & 13.60 \(\pm\) 0.01 b \\ \hline
20\%\_S & 32.95 \(\pm\) 0.03 s & 12.14 \(\pm\) 0.03 c & 3.92 \(\pm\) 0.01 s & 17.92 \(\pm\) 0.06 e & 12.76 \(\pm\) 0.02 c \\ \hline
10\%\_T & 34.91 \(\pm\) 0.03 f & 13.50 \(\pm\) 0.05 a & 4.33 \(\pm\) 0.02 e & 17.75 \(\pm\) 0.12 e & 14.18 \(\pm\) 0.05 a \\ \hline
20\%\_T & 32.32 \(\pm\) 0.01 h & 12.95 \(\pm\) 0.03 b & 4.03 \(\pm\) 0.02 f & 17.29 \(\pm\) 0.07 f & 13.56 \(\pm\) 0.03 b \\ \hline  & & & After storage & & \\ \hline
10\%\_S & 39.02 \(\pm\) 0.03 a & 6.85 \(\pm\) 0.03 e & 7.08 \(\pm\) 0.03 a & 7.39 & 45.93 \(\pm\) 0.21 a & 9.85 \(\pm\) 0.04 d \\ \hline
20\%\_S & 35.96 \(\pm\) 0.03 d & 6.72 \(\pm\) 0.03 f & 4.79 \(\pm\) 0.03 d & 6.27 & 35.50 \(\pm\) 0.14 c & 8.25 \(\pm\) 0.03 f \\ \hline
10\%\_T & 38.19 \(\pm\) 0.03 b & 7.66 \(\pm\) 0.03 d & 5.70 \(\pm\) 0.03 b & 6.84 & 36.64 \(\pm\) 0.12 b & 9.55 \(\pm\) 0.04 e \\ \hline
20\%\_T & 36.25 \(\pm\) 0.03 c & 7.76 \(\pm\) 0.03 d & 5.49 \(\pm\) 0.03 c & 6.67 & 35.28 \(\pm\) 0.15 c & 9.50 \(\pm\) 0.03 e \\ \hline \hline \end{tabular}  
* Within the column, means followed by different superscripts are significantly different at \(p\leq\) 0.05 (ANOVA, Fisher’s LSD). \(\sim\)citrus fiber/blackberry gels with sucrose; T—citrus fiber/blackberry gels with trehalose. \(\Delta\)E—change of color of citrus fiber/blackberry gels after storage in relation to gels after preparation.  
\end{table} 
Table 7: Color parameters (L*, a* and b*) of citrus fiber/blackberry gels prepared with different disaccharides after preparation and storage. Retention or loss of volatile and phenolic compounds depended on the composition of gels and interactions between those compounds. The main difference between gels was in disaccharides and their amounts. Disaccharides used in this study were two chemical isomers, sucrose and trehalose. As proven in other studies, as well as in this one, their behavior in a complex matrix can be different. The behavior of those disaccharides caused by their interactions affected the investigated parameters differently. It is well-known that water has a very specific and important role as a solvent and a reactant in many chemical reactions in foods. Those reactions together with oxidation and molecular mobility can cause degradation of sensitive compounds [42]. Sucrose and trehalose showed different behaviors in model water solutions, which are much simpler systems than fruit matrices. Trehalose has a higher effect on water structure since it has a higher affinity for water and can bind with a higher number of water molecules. Additionally, trehalose forms larger clusters in water than sucrose. Based on hydration number, radius of gyration, glycosidic dihedral angles and cluster formation, it was determined that trehalose-water solutions were more homogeneous than sucrose-water solutions [43]. Trehalose's impact on water molecules was also proven by investigation of single-particle and collective rotation and translation of water, in which it was concluded that trehalose had a slightly greater effect on these properties than sucrose [44]. In comparison to sucrose, it was observed that trehalose had a stronger perturbing effect on the water structure and that water molecules interacted slightly differently with the different atomic sites of these two disaccharides [45].