## 3 Results  
### Qualitative and Semiquantitative Volatile Profile  
In the current study, the volatile composition detected in apple-fruit, -juice, and -cider samples (142 VOCs) was characterized by the presence of 58 esters, 34 alcohols, 19 aldehydes, 10 ketones, 8 terpenoids, 7 acids, 3 sulphur compounds, 1 dioxolane, 1 lactone, and 1 aromatic hydrocarbon (Table 1). In apple fruits and juices, major chemical families were esters (on average, 24.45% and 18.82% for the total volatile composition, respectively), alcohols (24.36% and 37.94%), and aldehydes (24.60% and 37.23%). Nevertheless, an exception was observed for Branco apple fruits, since the contribution of terpen (18.71%) for the total volatile profile was higher than that of esters (9.92%). On the other hand, esters (51.12%), alcohols (42.92%), and acids (5.29%) were the predominant chemical families in ciders (Figure 1). Specifically, in ciders, the relative concentration of esters increased 9- and -12-fold on average in comparison with fruits and juices, respectively, due to the fermentation process. Additionally, alcohols are other chemical compounds were found in high concentration in ciders (4407.18 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\) on average), \(\sim\)6- and 4-fold, when compared to apple fruits and juices, respectively (773.66 and 1157.17 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\) on average, respectively) (Figure 1).  
In apple fruits, the VOCs of highest relative concentration were 2-hexenal (on average, 428.83 \(\mathrm{\SIUnitSymbolMicro g}\) kg\({}^{-1}\)), 1-hexanol (403.70 \(\mathrm{\SIUnitSymbolMicro g}\) kg\({}^{-1}\)), and \(\alpha\)-farnesene (368.27 \(\mathrm{\SIUnitSymbolMicro g}\) kg\({}^{-1}\)); in juices, they were 2-hexenal (on average, 663.13 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\)), 1-hexanol (515.70 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\)), and 3-methyl-1-butanol (367.07 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\)). In ciders, the VOCs of highest relative concentration were ethyl octanoate (on average, 3659.23 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\)), ethanol (2582.63 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\)), and 3-methyl-1-butanol (1439.60 \(\mathrm{\SIUnitSymbolMicro g}\) L\({}^{-1}\)), as shown in Table 1.  
Among 142 identified and semiquantiified VOCs, only 9 (acetaldehyde (1), ethyl acetate (3), ethanol (8), ethyl butanoate (17), ethyl 2-methylbutanoate (20), 1-butanol (29), ethyl hexanoate (43), hexyl acetate (49) and 1-hexanol (67)) were common in all analysed matrices (fruit, juice, and cider) and in all apple-tested varieties (Festa, Branco, and Domingos) (Figure 2).  
Among these 9 VOCs, acetaldehyde (1), ethyl butanoate (17), and ethyl 2-methylbutanoate (20) were higher in fruits than in juices and ciders, whereas ethyl acetate (3), ethanol (8), ethyl hexanoate (43), and hexyl acetate (49) were the largest VOCs detected in ciders. In the current study, there were statistical differences (\(\mathrm{p}<0.05\)) among the relative concentrations of these common VOCs according to different matrices and among apple varieties (Table 1). Nonetheless, in the case of acetaldehyde (1), there were no differences in the juices from three apple varieties. Similarly, when we compared apple fruits from 3 varieties for ethyl hexanoate (43), there were no statistically significant differences. Related to 1-hexanol (67), there were no statistical differences among fruits, juices, and ciders from the Domingos variety (Table 1 and Figure 2).  
Figure 1: Bar graphics comparing apple (**A**) fruit, (**B**) juice, and (**C**) cider samples. Different lowercase letters indicate significant differences among varieties for the same chemical family (E, esters; AL, alcohols; A, aldehydes; K, ketones) at \(p<0.05\) according to analysis of variance (ANOVA) and multiple-range Tukey test.