# Establishment of the Volatile Signature of Wine-Based Aromatic Vinegars Subjected to Maceration
## 2 Results and Discussion
### Characterization of Volatile Signature of WBAV by Maceration Using HS-SPME/GC-MS  
Aroma is an important quality criteria for vinegars. Thus, the identification of VOCs responsible for its aroma is considered to be a key factor for quality and authentication control [4; 19; 22]. HS-SPME/GC-MS method was applied to establish the volatile signature of wine (control) and WBAV (banana, passion fruit, apple, pennyroyal). A total of 103 VOCs were identified in vinegar samples (Table 1) belonging to different chemical families, namely ethyl esters (37), alcohols (20), acids (10), terpenoids (23), carbonyl compounds (six), lactones (five) and volatile phenols (two). As far as we know, 34 of these VOCs are reported herein for the first time in vinegars (Table 1). These VOCs have been already identified by matching the obtained mass spectra with the reference compounds spectra in NIST Mass Spectral Search Program with a resemblance percentage above 80% and by comparison of the RIs calculated (KI\({}_{\text{calc}}\)) with the values reported in the literature (KI\({}_{\text{lit}}\)) for polyethylene glycol (or equivalent) column in vinegar samples using HS-SPME/GC-MS (Table 1). A range between 0 and 36 (\(\,\mathrm{I}\mathrm{K}\mathrm{I}_{\text{calc}}-\mathrm{K}\mathrm{I}_{\text{ lit}}\,\)1) was obtained for KI\({}_{\text{cal}}\) compared to the KI\({}_{\text{lit}}\) reported in the literature for one dimensional GC with polyethylene glycol GC column or equivalent. This difference in KI is acceptable (<5%) taking into account that the literature data is obtained from a large range of GC stationary phases (several commercial GC columns are composed of polyethylene glycol or equivalent stationary phases). Forty-six VOCs were common in all vinegar samples analyzed, namely 17 ethyl esters, 11 alcohols, nine terpenids, six acids, two lactones and one volatile phenol (Table 1). Moreover, some new VOCs, not found in wine vinegar (control)--mainly ethyl esters (e.g., ethyl 3-hexenoate) and terpenoids (e.g., limonene oxide, bornyl acetate, menthol)--appear in WBAV, as result of the maceration process. However, their contribution to the volatile signature was different for each vinegar sample, according to the raw material used. Table 1 shows the mean of GC peak area for each WBAV under study. The distribution of VOCs, according to its chemical family, is represented in Figure 3. Alcohols were the predominant chemical family in the studied vinegars. On average, the % RPA of alcohols was higher in WBAV, ranging from 42.10 (banana vinegar) to 54.91 % (apple vinegar), than in wine vinegar (control, 39.97%). Ethanol, 3-methylbutanol and 2-phenylethanol were markedly the most abundant alcohols identified in all vinegar samples. The presence of these VOCs in vinegar samples can contribute positively with flower, fruity and sweet notes for sensory properties. Due to its importance in terms of quality and acceptance by consumers and because there are no published reports on this subject, the sensory expression of WBAV is being evaluated in an ongoing work aiming to define its main odor descriptors. In addition the limiar of olfactive perception of the most significant volatiles will be established in order to evaluate its contribution to the sensory characteristics of vinegars. 2-Hexanol, 2-heptanol, 1-octanol, 1-octne-3-ol, 2-nonanol, 2,3-butanediol isomer and methionol were detected in all WBAVs, with the exception on pennyroyal vinegar. Moreover, 2-butanol was not detected in WBAV macerated with passion fruit and apple.