## 2 Results and Discussion
### Volatiles of Citrus Fiber/Blackberry Gels
The most volatiles from citrus fiber lost during the preparation of gels belonged to this group of volatiles (furaldehyde, benzaldehyde, methyl heptenone, 3-octen-2-one, 3,5-octaladiene-2-one and 2-butyl-2-octenal). In addition, 2-heptenal, 1-octen-3-one and 6-methyl-5-hepten-2-one formed through preparation. 2-heptenal was formed in higher amounts in gels prepared with sucrose. Regardless of disaccharides type, a higher amount of this volatile was formed when 20% of disaccharide was used for preparation. A similar tendency as a result of gel formation was observed for 1-octen-3-one. Type of disaccharide did not have an effect on the formation of 6-methyl-5-hepten-2-one, only their amount, with this volatile formed in higher amounts in gels with 20% of disaccharide. Hexanal, octanal, 2-nonenal and decanal were identified in citrus fiber, and their amounts decreased during the preparation of gels. The highest retention of hexanal was achieved with the lower amounts of disaccharides, and the type of disaccharide did not affect the retention of this volatile. Octanal was identified in higher amounts in gels with sucrose. These gels also had higher amounts of 2-nonenal, but the percentage of disaccharides did not have an impact on the retention of this aldehyde during processing. On the other hand, decanal was determined in higher amounts in gels with trehalose. Lily aldehyde and 2,4-nonadienal were identified in blackberry juice, and their amount significantly decreased during the preparation of gels, but both of them were better retained in gels with sucrose. Heptanal, 2-octenal, 2-decenal and geranyl acetone were volatiles identified in blackberry juice and in citrus fiber as well as in gels. During the preparation of gels, all of these volatiles were retained in higher amounts in sucrose-containing gels. Carvone, m-cytene and trans-carveol were identified only in citrus fiber, and those terpen were lost during the preparation of gels. Guaicaol, trans-verbenol, nerol and \(\gamma\)-ionone were identified in juice and gels but in lower amounts. Trans-verbenol and \(\gamma\)-ionone were retained better in gels prepared with sucrose, while nerol was better retained in gels with trehalose. In blackberry juice, citrus fiber and gels, D-limonene, linalool, \(\alpha\)-ionone and \(\beta\)-ionone were determined. D-limonene was the most abundant volatile in citrus fiber and also in gels. Higher retention of D-limonene was achieved when sucrose was used for the preparation of gels. Those gels also had higher amounts of \(\alpha\)-ionone and \(\beta\)-ionone, while linalool was determined in higher amounts in gels with trehalose. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Volatiles** & **BJ** & **F** & **10\%\_T** & **20\%\_T** & **10\%\_S** & **20\%\_S** \\ \hline \multicolumn{5}{c}{Alcohols} \\ \hline
2-ethylhexanol & 20.74 \(\pm\) 0.01 & 5.08 \(\pm\) 0.59 & 12.39 \(\pm\) 0.07 d & 13.54 \(\pm\) 0.02 c & 14.33 \(\pm\) 0.05 b & 22.93 \(\pm\) 0.28 a \\ \hline benzyl alcohol & - & - & 21.42 \(\pm\) 0.04 c & 23.03 \(\pm\) 0.89 b & 17.86 \(\pm\) 0.01 d & 25.71 \(\pm\) 0.37 a \\ \hline
1-octanol & 11.90 \(\pm\) 0.11 & 23.84 \(\pm\) 1.54 & 16.45 \(\pm\) 0.08 c & 15.58 \(\pm\) 0.28 d & 19.09 \(\pm\) 0.05 b & 20.39 \(\pm\) 0.09 a \\ \hline
1-octen-3-ol & - & 50.28 \(\pm\) 2.56 & - & - & - & - \\ \hline phenethyl alcohol & 47.39 \(\pm\) 0.48 & - & 11.77 \(\pm\) 0.05 b & 9.91 \(\pm\) 0.04 c & 11.89 \(\pm\) 0.11 b & 13.99 \(\pm\) 0.10 a \\ \hline perillyl alcohol & 29.19 \(\pm\) 1.98 & 3.44 \(\pm\) 0.25 & 3.52 \(\pm\) 0.08 b & 3.59 \(\pm\) 0.23 b & 2.78 \(\pm\) 0.01 c & 4.67 \(\pm\) 0.10 a \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The amounts of volatiles of blackberry juice (BJ), citrus fiber (F) and citrus fiber/blackberry gels prepared with different disaccharides after preparation.