## 3 Results
### Extraction of Aromatic Compounds versus Type of Closure
Therefore, the TD method allowed for the extraction of another triterpene, Friedelin. This is a compound of the triterpene fraction of cork, and it is described as a precursor of bioactive components for biomedical applications [63], D-limonene or a monoterpene was also obtained using TD, as in the case of TDN, or a C13-norisoprenoid. According to [PERSON] et al. 2010 [26] and [PERSON] et al. 2003 [64], TDN, which forms from the degradation of carotenoids, is affected by the aging process through acid-catalyzed reactions. Along with diethyl succinate and vitispirane, TDN can be used to distinguish sparkling wines aged for more than 20 months. However, beyond this, due to the relatively low concentrations of these compounds and the complexity of the matrix, their analyses require the previous fractionation and separation of volatile terpen or a non-polar fraction from a polar fraction [65]. There are several compounds classified as other. HP-SPME allowed for the extraction of most of them, such as lactamide or dimethylamine. Caprylic anhydride was obtained by both methods. Some of them have not been described previously. According to our results, HS-SPME may a useful extraction method for esters, ketones and other compounds, while for the extraction of alcohol, acid, ethers, alkanes and terpen, the TD methodology is better. It was initially expected that TD extraction would be more efficient due to the advantages mentioned earlier. Considering these results, a first step, with the aim of the optimization of the TD methodology, would be necessary to gear its strengths. Some desorption parameters, such as desorption time, desorption temperature, low trap cryo-temperature or high trap temperature, and its associations would affect the response of the volatile compounds [43]. Ref. [23] considered that HP-SPME allows for the extraction of the most representative polar compounds of a sparkling wine. In this study, HP-SPME enabled the extraction of several high-molecular-weight compounds, such as acetate, ethyl, and isoamyl esters, which appear to be characteristic aromas of sparkling wines with a short aging period. According to [64], HP-SPME is proven to be an effective method for detecting diethyl succinate, TDN, hexanol, and other compounds associated with the autolysis process, as well as compounds inherent in the bouquet of long-aged sparkling wines. The behaviors of the cork stoppers and screw caps used in bottle aging, after the second fermentation of the sparkling wine samples, are shown in Figure 4.  
Esters was the most abundant family of compounds in both types of closures. Levels of some families of volatile compounds--for example alcohols, acids and others--are those with wide differences between the type of closures. As previously mentioned, volatile esters represent one of the most significant groups of compounds due to their crucial role in shaping the volatile profile [59]. They contribute to the presence of fruity and floral-like notes in the sparkling wine aroma [1,2,18], and it appears that this is the result of the autolysis of the yeast. Some factors such as the yeast strain or fermentation conditions (temperature, nutrient content, or availability of oxygen) have already been linked to the formation of volatile esters [1,3]. Therefore, the type of closure would be related to the preservation of the levels of ester compounds in sparkling wine, improving the shelf life of the product. The percentage of the ester area is similar in both closures. Among the esters present in the analyzed sparkling wines, methyl 2,4-dimethylhexaneoate was the most abundant ester and was only detected in screw-cap closures. Methyl esters in wine are related to yeast fermentation [66]. Ethyl acetate and ethyl esters with a high molecular weight, such as ethyl octanoate (floral), ethyl hexanoate (fruity), ethyl decanoate (floral), ethyl anachidate and diethyl succinate (overripe), were detected in all samples. As noted by [66], these compounds can exhibit a synergistic effect, even when present in small quantities.