## 2 Results and Discussion
### Volatiles of Citrus Fiber/Blackberry Gels  
The flavor profile of the product depends on the flavors of each ingredient that was used for preparation. In our case, sources of volatiles were blackberry juice and citrus fiber. Additionally, some volatiles can be formed during processing. Identified individual volatiles in blackberry juice, citrus fiber and citrus fiber/blackberry gels, molecular weights, hydrophobicity, vapor pressure and odor descriptions are presented in Table 1. In blackberry juice, 19 volatiles were identified, while for citrus fiber, there were 28 and in gels, 29 volatiles. Some of those volatiles were identified only in citrus fiber, such as furaldehyde, 1-octen-3-ol, benzaldehyde, methyl heptenome, m-cymene, 3-octen-2-one, 3,5-ocadiene-2-one, myrtrenal, 2-butyl-2-octenal, decanol, trans-carveol and carvone, but some of them were also formed during the preparation of gels, such as benzyl alcohol, 2-heptenal, 1-octen-3-one, 6-methyl-5-hepten-2-one and phellandral. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Volatiles** & **BJ** & **F** & **CBg** & **RT** & **RI** & **CAS** & **MW** & **LogP** & **VP** & **(mm/Hg)** & **Odor** \\ \hline hexanal & \(-\) & + & + & 5.13 & 800 & 66-25-1 & 100.2 & 1.80 & 10.888 & green \\ \hline furaldehyde & \(-\) & + & \(-\) & 6.40 & 827 & 98-01-1 & 96.09 & 0.410 & 2.234 & bready \\ \hline heptanal & + & + & + & 10.76 & 897 & 111-71-7 & 114.2 & 2.30 & 3.854 & green \\ \hline benzaldehyde & \(-\) & + & \(-\) & 14.65 & 956 & 100-52-7 & 106.1 & 1.48 & 1.270 & fruity \\ \hline
2-heptenal & \(-\) & \(-\) & + & 14.95 & 956 & 2463-63-0 & 112.17 & 2.30 & 1.823 & green \\ \hline
1-octen-3-one & \(-\) & \(-\) & + & 16.46 & 982 & 4312-99-6 & 126.2 & 2.40 & 1.063 & fruity \\ \hline
1-octen-3-ol & \(-\) & + & \(-\) & 16.50 & 980 & 3391-86-4 & 128.2 & 2.52 & 0.531 & earthy \\ \hline methyl heptenone & \(-\) & + & \(-\) & 16.95 & 985 & 110-93-0 & 126.2 & 1.95 & 1.277 & citrus \\ \hline
6-methyl-5-hepten-2-one & \(-\) & \(-\) & + & 17.11 & 987 & 110-93-0 & 126.2 & 1.90 & 1.277 & citrus \\ \hline octanal & \(-\) & + & + & 18.08 & 998 & 124-13-0 & 128.2 & 2.70 & 2.068 & green \\ \hline hexanoic acid & \(-\) & + & + & 18.54 & 1005 & 142-62-1 & 116.1 & 1.90 & 0.158 & fatty \\ \hline m-cymene & \(-\) & + & \(-\) & 19.02 & 1014 & 535-77-3 & 134.2 & 4.5 & 1.720 & - \\ \hline D-limonene & + & + & + & 19.41 & 1018 & 138-86-3 & 136.2 & 4.57 & 0.198 & citrus \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Volatile compounds identified in blackberry juice (BJ), citrus fiber (F) and citrus fiber/blackberry gels (CBg), and their properties. The amounts of volatiles in blackberry juice, citrus fiber and citrus fiber/blackberry gels after preparation with different disaccharides are presented in Table 2. Types of disaccharides and their percentages had an impact on the amounts of volatiles in gels. All volatiles were divided into four groups: alcohols, acids, aldehydes and ketones and terpen. Five alcohols were identified in gels. Benzyl alcohol was not detected in blackberry juice and in citrus fiber, and thus this volatile was formed during the preparation of gels, probably from benzaldehyde that was identified in citrus fiber but not in juice and gels. Benzyl alcohol was identified in a higher amount when 20% of disaccharides were used for the preparation of gels. Phenethyl alcohol was found in juice, and was retained in gels after their preparation. The highest amount of this alcohol was determined in gels with 20% of sucrose and the lowest with 10% of the same disaccharide. There was no difference between the two gels prepared with trehalose. The remaining alcohols, 2-ethyllexanol, 1-octanol and perillyl alcohol, were identified in all samples. 2-Ethylhexanol and 1-octanol were determined in higher amounts in gels prepared with sucrose regardless of its percentage.