# Differentiation of Fresh and Processed Fruit Juices Using Volatile Composition
## 2 Results and Discussion
### Volatomic Signature of Fresh and Processed Fruit Juices
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c c c} \hline \hline
**Feak** & **RT** & **RT** & **RG\({}^{2}\)** & **KI\({}_{\text{La}}\)** & \multicolumn{1}{c}{**Si**} & \multicolumn{1}{c}{**Clinical Groups**} & \multicolumn{1}{c}{**Grope**} & \multicolumn{1}{c}{**Red fruits**} & \multicolumn{1}{c}{**Orange**} & \multicolumn{1}{c}{**Pear**} & \multicolumn{1}{c}{**Apple**} \\ \cline{3-14}
**n\({}^{\circ}\)** & (min) & **R**\({}_{\text{Ge}}\) & **R**\({}_{\text{La}}\)** & \multicolumn{1}{c}{**Si**} & \multicolumn{1}{c}{**Si**} & \multicolumn{1}{c}{**Si**} & \multicolumn{1}{c}{**Feish**} & \multicolumn{1}{c}{**Proceed**} & \multicolumn{1}{c}{**Feish**} & \multicolumn{1}{c}{**Proceed**} & \multicolumn{1}{c}{**Feish**} & \multicolumn{1}{c}{**Proceed**} & \multicolumn{1}{c}{**Feish**} & \multicolumn{1}{c}{**Proceed**} \\ \hline  & & & & & & & & & & & & & & & & & & \\  & & & & & & & & & & & & & & & & & & & \\
77 & 37.12 & 1457 & 1458 & 3.39 & (1) & 159.04 & (0) & 0.79 & (7) & 194.85 & (7) & 4.67 & (8) & 124.55 & (10) & 1.25 & (1) & 207.37 & (3) & - & - & - & 27.73 & (3) & - & - & - & - \\
93 & 43.71 & 1562 & 1350 & 5.34 & (0) & 24.06 & (0) & 24.06 & (1) & 35.75 & (0) & 0.15 & (3) & 3.87 & (0) & 0.05 & 8.82 & (0) & 0.11 & 6.44 & (0) & 12.43 & (0) \\  & & & & & & & & & & & & & & & & & & & \\  & & & & & & & & & & & & & & & & & & & \\ \hline \hline \end{tabular}  
* 1 RT: Retention time (min). 2 Kout index relative n-alkanes (Cs to C\({}_{0}\) on) a BP-20 capillary column. 3 Kout index relative, reported in literature for equivalent capillary column [(34; 41; 42; 43; 44)].
* 4 Volatile organic compounds (VOCs) identified by standard; : Not detected; TON; 12.4-dihydro-1.1,6-trimethylInphalene: Different superscript lowercase letters in a row indicate no significant differences between mean values at \(p<0.05\), obtained by one-way ANOVA, followed by Tukey’s test, for post-hoc multiple comparisons of means, for fresh and processed fruit juice (\(n=2\)).  
\end{table} 
Table 1: _Cont._In orange and grape juices, terpenoids was the most predominant chemical group, accounting for 53.0 and 32.9% of the total volatile composition of fresh juices, and 51.2 and 21.4% of that of processed juices, respectively. While the number of identified terpenoids in orange, pear, and apple juices was similar, its GC peak area in fresh and processed orange juices was three and four times higher than observed in fresh and processed juices from pear and apple, respectively. This trend is explained by the high GC peak areas of limonene, which were followed by those of germacrene D, geranyl acetone isomer and linalool, observed in orange juices (Table 1 and Table S2). On average, limonene represents 11.6 and 6.3% of the total volatile profile of fresh and processed juices, respectively. On the other hand, the number of terpenoids identified in orange juice, independently of the type of juice, was two times higher than that in grape juice. The contribution of this chemical group to the total volatile profile of grape juice was two times higher than its contribution to that of red fruits, apple, and pear juices, irrespective of the type of juice (Table 1). Dihydrodinalool, followed by linalool and \(\alpha\)-terpineol, were the predominant terpenoid identified in grape juices (Table S2). In the studied fresh juices, the contribution of alcohols to the total volatile profile ranged from 10.1 (orange) to 18.1% (grape), whereas in processed juices its contribution ranged from 9.7 (orange) to 20.7% (pear). The ethanol content was higher in the fresh juices from grape, orange, and pear than in the corresponding processed juices, whereas in the red fruit juices and apple juices, the GC peak area of ethanol was higher in the processed juices than in the fresh juices. 1-Propanol was the second most dominant alcohol in grapes and red fruit juices, whereas 3-methyl-1-butanol was the most dominant alcohol in orange and apple juices.