## 2 Results and Discussion
### Volatile Composition of Viura Wines Treated with PS extracts and CM
The higher decreasing effect of higher alcohols in Viura wines treated with WPP after twelve months could also beattributed to hydrophobic interactions, hydrogen bonds, and/or \(\pi\)-\(\pi\) stacking of the RG-II glycosidic groups, with the largest aromatic family being found in Viura wines. Most higher alcohols are related to herbaceous aromas with pungent and strong notes. Therefore, the use of PS extracts in this study had positive effects on the aroma of the wine. Wines treated with DWRP and CM increased the contents of C6 alcohols after one month of bottling (T1), while WPP had no effect. After twelve months of bottling (T12), no differences were observed among these aromatic compounds, except for benzyl alcohol, which presented higher concentrations in those wines treated with PS extracts, but it was below its OAV in all the wines (Table 2). Since WPP had no effect on C6 alcohols at T1, and was mainly composed of RG-II (74.7%) [23], the retention effect of DWRP and CM at T1 could be attributed to the protein part of the PRAG in DWRP extract and MP in CM. On the other hand, the loss of the retention effect after twelve months could be due to the fact that these interactions between these aromatic compounds and PS are reversible, which means that the aromatic compounds can be gradually released by the formation of colloidal barriers or absorbing free ethanol molecules to break up the Marangoni effect in wines with an ethanol degree >5% [15; 31; 35]. Higher MP (or proteic PS) contents could produce higher retention effects [31; 36]. C\({}_{6}\)-C\({}_{10}\) fatty acids are usually related with unpleasant aromas (Table 2); however, they can prevent the hydrolysis of esters [37]. Those wines treated with DWRP and CM extracts presented higher retention of these volatile compounds after one month of aging, which can be due to the higher hydrophobicity of fatty acids because of their carbonyl and hydroxyl groups that can react with some PS as MP [35] and RG-II, which also has been related to the increase in fatty acids in solution [15]. However, no significant differences were observed in the concentrations of the fatty acids between wines treated with PS extracts and control wines after twelve months of bottling. Regarding the rest of volatile families, the addition of CM, and specially DWRP extracts, increased the contents of ethyl esters, acetates, volatile phenols, and terpen after one month of bottling (T1), and presented a great retention effect of most of these volatile compounds after twelve months (T12), since their contents were significantly higher than in the control wines. The use of WPP extracts increased the concentration of total terpen at T1, related to varietal odorants in wine [38], as well as total ethyl esters and terpenes at T12. The addition of CM increased the content of total ethyl esters, acetates, and terpenes both at T1 and T12. The addition of DWRP extracts increased the content of total ethyl esters, acetates, phenols, and terpenes both at T1 and T12. Our results indicated that PS extracts had a satisfactory retention effect on compounds related to fruity aromas [28], as ethyl octanoate and ethyl hexanoate, which presented some of the highest OAVs of the Viura wines (Table 2), and isoamyl acetate and \(\beta\)-phenethyl acetate, providing banana and apple notes to the wine [28]. However, WPP had a lower retention effect than DWRP and CM on most of the volatile compounds.