## 2 Results and Discussion
### Odor Activity Values  
The odor activity value (OAV) was frequently used to indicate the contribution of the volatile compounds to the overall aroma in the wine [25; 26]. Generally, a volatile with OAV (\(>\)1) was suggested to exhibit contributions to the overall aroma, however, it is also reported that a compound with \(0.1<\text{OAV}<1\) should also be considered in agreement with the acknowledged theory that sub-threshold compounds may also contribute to wine aroma through additive effects of compounds with similar structure or odor [30]. According to OAV, the volatile compounds that could significantly contribute their flavor notes to the overall aroma of icewines are listed in Table 3. A total of 16 compounds with an OAV above 1 were identified, among them, \(\beta\)-damascenone showed the highest OAV value, followed by ethyl hexanoate. For \(\beta\)-damascenone, BT and SP did not show significant differences, however, in MF and CF it decreased by 20% and 63%, respectively. Furthermore, ethyl hexanoate reduced by 20-80% especially in MF. Other compounds with high OAVs were isoamyl acetate (reduced by 3-33%) and linalool (decreased by 10-20%), but both with OAVs \(>\)10. Rose oxide also showed relatively high OAV but was only detected in the control and MF wine samples.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & **Odor** & **Odor Threshold** & \multirow{2}{*}{**Reference**} & \multicolumn{6}{c}{**Odor Activity Value**} & \multirow{2}{*}{**Aroma Classes**} \\  & **Description** & & & & & & & & \\ \cline{5-10}  & **Description** & & & & & & & & \\ \hline Ethyl acetate & Finemeyerle, fruity, balancing & 7500 & c & 0.60 & 0.46 & 0.60 & 0.54 & 0.42 & 2.7 \\ Isobutyl acetate & Fruits apple & 20 & a & 0.12 & 0.07 & 0.11 & 0.07 & 0.02 & 2 \\ Ethyl butyrate & Fruat, fruity & 20 & a & 2.47 & 1.34 & 2.08 & 2.30 & 1.72 & 1.2 \\ Isoamyl acetate & Bannan & 30 & a & 164.65 & 117.6 & 15.44 & 14.97 & 11.01 & 2 \\ Ethyl hexanoate & Fruity, green apple & 14 & a & 197.62 & 96.85 & 153.02 & 154.18 & 40.59 & 2 \\ Ethyl heptamate & Finemeyerle, fruity & 220 & c & 0.21 & -0.11 & 0.16 & 0.13 & -0.11 & 2 \\ Ethyl octanoate & Ripe fruits, gear, wetty & 240 & a & 119.6 & 3.20 & 7.11 & 7.46 & 2.99 & 2 \\ Ethyl decanoate & Fruits peanut fruitty & 200 & b & 8.68 & 3.79 & 6.25 & 5.11 & 1.35 & 2 \\ Ethyl succinate & Fruity, cheese & 6000 & c & 0.13 & 0.11 & 0.12 & 0.12 & 0.12 & 2.3 \\ Ethyl phenylacetate & Fruat, honey & 73 & c & 0.25 & 0.19 & 0.20 & 0.24 & 0.00 & 1 \\ Ethyl methyl acetate & Bread & 250 & a & 0.37 & 0.36 & 0.36 & 0.35 & 0.14 & 1 \\ Ethyl dodecanoate & Oliv, fruity, fruity & 1500 & b & 0.48 & 0.30 & 0.44 & 0.25 & 0.05 & 2.3 \\ \(\delta\)-Dodecanice & Covant fruitty & 500 & c & 0.09 & 0.08 & 0.07 & 0.08 & 0.00 & 2 \\ Ethyl myrivate & Mild way, worry & 500 & d & 0.43 & 0.25 & 0.41 & 0.28 & 0.06 & 3 \\ Ethyl hexadecanice & Mild way & 1000 & d & 0.13 & 0.13 & 0.12 & 0.11 & 0.04 & 3 \\ \(1\)-Fentanyl & Balsam, bitter diamond & 64,000 & b & 0.09 & 0.09 & 0.09 & 0.08 & 7 \\ \(1\)-Hexameth & Rehexhexosa, grass, woody & 1100 & b & 1.00 & 1.02 & 0.98 & 0.97 & 0.74 & 6 \\ \(\varepsilon\)-3-Hexenn-1-cl & Plant, fruity, aromatic & 400 & a & 0.17 & 0.15 & 0.16 & 0.16 & 0.09 & 6.2 \\ \(1\)-Corn-3-cl & Mushdown & 20 & d & 7.37 & 7.05 & ND & 7.30 & 3.34 & 4 \\ \(1\)-Hemat & Olip & 200 & b & 0.32 & 0.27 & ND & 0.32 & 0.29 & 3 \\ \(1\)-Cornet &