# Flavor Profile Evolution of Bottle Aged Rose and White Wines Sealed with Different Closures
## 2 Results and Discussion
### Flavor Profile Analysis of Wines after an 18-Month Bottle Aging
#### 2.3.2 Flavor Characters  
To learn more about the aroma profile in rose and white wines, [PERSON]'s multiple range tests based on OAVs were applied to identify which types of closures had a different effect on wines after an 18-month bottle aging (Table 2). Overall, the rose and white wines were both fruity, floral, and sweet in odor, which makes sense given that most of the volatile compounds quantified in this study were esters and the thresholds of terpen and norisoprenoids were usually low. White wines exhibited more 'berry' and'sweet' odors, mainly due to the high level of ethyl esters, such as ethyl acetate, ethyl octanoate, ethyl decanoate, and ethyl dodecanoate (Table S2). During an 18-month bottle aging, the total intensity of aroma in both types of wines declined prominently, especially 'tropical fruity,' 'floral,' 'berry,' and'sweet' aroma descriptions. The results indicated that the period of bottle aging was likely to contribute to the loss of aroma properties. The decrease was more obvious in white wines, as the studies showed that white wines were very unstable and lost their desirable fresh and fruity characters over time [20]. According to the results of Duncan's multiple range tests, the difference between different closures mainly concerned the 'berry' and'sweet' odors. Ethyl acetate, ethyl 2-hydroxy-4-methylpentanoate, ethyl decanoate, and \(\beta\)-damascenone were representative compounds of those odorant series. Wine samples sealed with a screw cap contained a higher concentration of long-chain aliphatic acid esters, which might be the reason why it performed better in preventing 'berry' and'sweet' odors from declining. There was no significant difference between rose wines sealed with three natural corks (N1, N2, N3) and a screw cap (SC), except for the 'berry' aroma description.  
On the contrary, OAVs in rose wines sealed with a polymer synthetic plug (SP) were significantly lower than those sealed with other closures after an 18-month bottle aging. White wines with agglomerated cork (AC) and polymer synthetic plug (SP) had the lowest OAVs among other types of closures, indicating that those two types of closures were not appropriate for the preservation of white wines during bottle aging.  
As for chromatic characters, due to the decrease of anthocyanins in rose wines during bottle aging, a' values were much lower, while b* values were higher in final wines than in initial wines (Figure 6a), indicating that the hue tended to undergo a yellowing phenomenon after 18 months of bottle aging. Although the \(\Delta\)E values of rose wines in our research ranged from 1.62 to 2.37 and the chromatic difference in wines was perceivable by human eyes when the \(\Delta\)E value was above 2.8 [28], judging from the direct comparison in Figure 6a, visual differences existed in all rose wines after an 18-month bottle aging compared to the initial wines. This may be due to the extreme brightness caused by low color substances in rose wines, since it was reported that an \(\Delta\)E value >1.0 in model solutions was visually perceivable by the human eye [28]. The \(\Delta\)E value of white wines ranged from 0.08 to 0.33, corresponding to no visual differences in all white wines after an 18-month bottle aging (Figure 6b).