# Chemical Characterization of Cider Produced in Hardanger--From Juice to Finished Cider
## 3 Results and Discussion
### Volatile Compounds in Apple Juice and in Cider
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & \multicolumn{2}{c}{**Juice (mg L\({}^{-1}\))**} & \multicolumn{2}{c}{**Cider (mg L\({}^{-1}\))**} \\ \hline
**Parameter** & **Variety** & N & Mean (Min-Max) & N & Mean (Min–Max) \\ \hline Ethyl isovalerate & Aroma & 5 & 3.06 (1.50–8.60) & 7 & 9.34 (4.10–16.6) \\  & Discovery & 3 & **3.87** (1.30–8.60) & 3 & 7.43 (4.90–9.30) \\  & Gravenstein & 5 & 3.66 (1.50–11.4) & 3 & 12.9 (9.80–16.0) \\  & Summerred & 4 & **3.45** (1.50–8.70) & 4 & 7.08 (4.80–9.50) \\ \hline Ethyl 2-methylbutyrate & Aroma & 5 & 75.9 (17.4–165) & 7 & 68.5 (24.9–125) \\  & Discovery & 3 & 347 (20.0–986) & 3 & 153 (65.5–312) \\  & Gravenstein & 5 & **54.0** (17.4–164) & 3 & 56.1 (47.3–61.5) \\  & Summerred & 4 & **40.3** (16.8–101) & 4 & **52.9** (29.5–108) \\ \hline Ethyl leucate & Aroma & 5 & 4.70 (0.40–17.6) & 7 & 97.0 (25.6–340) \\  & Discovery & 3 & 482 (2.00–1442) & 3 & 21.1 (11.4–26.4) \\  & Gravenstein & 5 & 2.56 (1.60–4.10) & 3 & 141 (28.1–320) \\  & Summerred & 4 & 1.58 (0.70–2.30) & 4 & 30.0 (16.9–40.1) \\ \hline \multicolumn{5}{c}{Acetate esters} \\ \hline  & Aroma & 5 & 98.5 (23.3–170) & 7 & 86.5 (16.3–114) \\ propyl acetate & Discovery & 3 & 635 (167–1150) & 3 & 152 (54.9–279) \\  & Gravenstein & 5 & 10.1 (6.90–18.2) & 3 & 49.0 (19.1–85.7) \\  & Summerred & 4 & 8.95 (5.10–16.3) & 4 & 74.0 (20.7–130) \\ \hline Isobutyl acetate & Aroma & 5 & 47.0 (16.6–98.4) & 7 & 124 (30.8–352) \\  & Discovery & 3 & 64.0 (14.0–131) & 3 & 76.7 (55.3–88.1) \\  & Gravenstein & 5 & 5.80 (3.50–12.0) & 3 & 70.7 (30.8–107) \\  & Summerred & 4 & 7.18 (4.10–16.1) & 4 & 173 (47.3–297) \\ \hline Phenylethyl acetate & Aroma & 5 & 29.8 (9.2–69.2) & 7 & 401 (100–1402) \\  & Discovery & 3 & 45 (18.2–97.7) & 3 & 282 (228–330) \\  & Gravenstein & 5 & 18.56 (9.1–32.6) & 3 & 419 (246–570) \\  & Summerred & 4 & 13.25 (8.1–26.1) & 4 & 532 (221–1120) \\ \hline Butyl acetate & Aroma & 5 & **2249 (261–6480)** & 7 & **1573 (144–2821)** \\  & Discovery & 3 & **3286 (1366–4996)** & 3 & 924 (308–1948) \\  & Gravenstein & 5 & 82.3 (28.9–128.7) & 3 & 231 (108–342) \\  & Summerred & 4 & 46.02 (26.5–55.1) & 4 & 315 (121–623) \\ \hline Isoamyl acetate & Aroma & 5 & **150 (47.6–386)** & 7 & **1250 (314–2980)** \\  & Discovery & 3 & **537 (324–938)** & 3 & **1128 (769–1525)** \\  & Gravenstein & 5 & 6.56 (2.90–12.9) & 3 & **1962 (347–3381)** \\  & Summerred & 4 & 5.2 (1.70–14.3) & 4 & **4138 (2590–6243)** \\ \hline Hexyl acetate & Aroma & 5 & **796 (ND–2772)** & 7 & **517 (ND–1171)** \\  & Discovery & 3 & **1147 (ND–2650)** & 3 & **290 (164–382)** \\  & Gravenstein & 5 & 53.7 (ND–89.2) & 3 & **307 (78.0–615)** \\  & Summerred & 4 & 27.5 (ND–40.3) & 4 & **1241 (715–1817)** \\ \hline z-3-hexenyl acetate & Aroma & 5 & 3.40 (1.20–8.80) & 7 & 3.73 (0.90–8.30) \\  & Discovery & 3 & 2.97 (0.90–5.40) & 3 & 1.67 (0.90–2.20) \\  & Gravenstein & 5 & 0.92 (0.40–1.30) & 3 & 1.80 (1.00–3.00) \\  & Summerred & 4 & 0.65 (0.30–0.80) & 4 & 2.63 (1.60–4.30) \\ \hline E-2-hexenyl acetate & Aroma & 5 & 3.96 (1.10–9.30) & 7 & 0.97 (0.50–1.70) \\  & Discovery & 3 & 6.50 (3.00–11.5) & 3 & 0.83 (0.60–1.10) \\  & Gravenstein & 5 & 1.36 (0.50–2.30) & 3 & 0.87 (0.60–1.00) \\  & Summerred & 4 & 0.68 (0.50–1.00) & 4 & 1.05 (0.60–1.70) \\ \hline Ethyl phenyl acetate & Aroma & 5 & 0.44 (0.30–0.60) & 7 & 2.56 (1.00–4.60) \\  & Discovery & 3 & 0.40 (0.20–0.70) & 3 & 4.30 (2.80–6.20) \\  & Gravenstein & 5 & 0.42 (0.20–0.90) & 3 & 6.53 (2.20–13.5) \\  & Summerred & 4 & 0.30 (0.20–0.40) & 4 & 2.15 (1.70–2.60) \\ \hline \end{tabular}
\end{table} 
Table 4: _Cont._To evaluate the overall correlation between the measured volatile aroma compounds and apple cultivars, principal component analysis (PCA) was conducted for juice (Supplementary Materials Figure S1) and finished ciders (Figure 1). The PCA plot shows variation between different samples, indicating that production practice impacts the contents of volatile aromas. However, there is a grouping in the PCA plot.