# Effects of Ethanol Concentration on Oral Aroma Release After Wine Consumption
## 2 Results and Discussion
### Effects of Ethanol Concentration and Individual Differences on the Immediate Oral Aroma Release  
Immediate aroma release refers to the aroma compounds trapped in a SPME fiber immediately after the panelists rinsed their mouths with the wine samples and expectorated (Figure 1). Data obtained for the 10 volunteers in each of the wines were submitted to two-way ANOVA analyses considering individuals and ethanol content as factors and their interactions. Results (Table 2) showed that the effect of subjects on aroma release was highly significant (\(p<0.0001\)) for all the assayed compounds (Table 2), which indicated a high interindividual variability on the immediate oral release of esters. The variability on the aroma released observed among individuals equally trained in the same consumption procedure and using the optimized SPME conditions is not surprising and it could be related to differences in oral physiological factors, such as, salivary flow rate and composition or oral cavity volume, among others, as it has been previously described in different works [8; 9; 10; 11]. Regarding the effect of ethanol content on the immediate oral aroma release, it seemed that this effect was less important than the subject effect and aroma compound and ethanol concentration-dependent (Table 2). To better visualize these results, data were plotted, and shown in Figure 2. To do so, data were normalized considering the values obtained for the 0.5% \(v\)/\(v\) as 0% and calculating the ratio for the other two wines. As can be seen, the oral release of two compounds (isoamyl acetate andethyl hexanoate) was not significantly affected by variations in the ethanol content. Moreover, certain compounds (ethyl butyrate and ethyl pentanoate) showed a significantly higher immediate oral release after the consumption of the wines with high ethanol content (5% \(v\)/\(v\) and 10% \(v\)/\(v\)) compared to 0.5% \(v\)/\(v\), while others (ethyl octanoate and ethyl decanoate) showed the opposite behavior. The differences \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Aroma** & **CAS** & **MW a** & **log P b** & **BP c (c C)** & **Solubility d** & **Aroma Descriptor e** \\
**Compounds** & **Number** & **(g/mol)** & **log P b** & **BP c (c C)** & **(mg/L)** & **Aroma Descriptor e** \\ \hline Ethyl butyrate & 105-54-4 & 116.16 & 1.85 & 125.79 & 4900 & Pineapple Strawberry \\ Isoamyl acetate & 123-92-2 & 130.19 & 2.26 & 134.87 & 2000 & Banana \\ Ethyl pentanoate & 539-82-2 & 130.19 & 2.34 & 148.37 & 2210 & Fruity \\ Ethyl hexanoate & 123-66-0 & 144.22 & 2.83 & 170.05 & 309 & Apple \\ Ethyl octanoate & 106-32-1 & 172.27 & 3.81 & 210.70 & 70 & Fruity apricot \\ Ethyl decanoate & 110-38-3 & 200.32 & 4.79 & 247.43 & 16 & Grape \\ \hline \hline \end{tabular} a
[FOOTNOTE:a]Footnote a: footnotetext: Molecular weight. b
[ENDFOOTNOTE]  
b
[FOOTNOTE:b]Footnote b: footnotetext: Hydrophobic constant estimated using molecular modeling software EPI Suite (U.S. EPA 2000–2007).  
c
[FOOTNOTE:c]Footnote c: footnotetext: Stability in water estimated using molecular software EPI Suite (U.S. EPA 2000–2007).  
d
[FOOTNOTE:d]Footnote d: footnotetext: Stability in water estimated using molecular software EPI Suite (U.S. EPA 2000–2007).  
e
[FOOTNOTE:d]Footnote d: footnotetext: Stability in water estimated using molecular software EPI Suite (U.S. EPA 2000–2007).  
e
[FOOTNOTE:e]Footnote e: footnotetext: Stability in water estimated using molecular software EPI Suite (U.S. EPA 2000–2007).  
e
[FOOTNOTE:e]Footnote e: footnotetext: Stability in water estimated using molecular software EPI Suite (U.S. EPA 2000–2007).  
[ENDFOOTNOTE]  
\end{table} 
Table 1: Physicochemical properties of the aroma compounds employed in this study.