# Accelerating Xinomavro Red Wine Flavor Aging Using a Pulsed Electric Field and Various Wood Chips
## 3 Results and Discussion
### VCs Analysis  
The HS-SPME/GC-MS analysis of Xinomavro red wine (a representative chromatogram of the HS-SPME/GC-MS analysis is given in Figure 1) elucidates a complex interplay between PEF treatment, various wood chip types, and the resulting chemical composition. Table 2 depicts the results as percentage (%) of each VC relative to the total identified VCs. This kind of representation provides a normalized view of the composition, allowing for a direct comparison of the relative contributions of different compounds within the mixture. During the HS-SPME/GC-MS analysis of the wine samples, 22 different VCs were identified. Only 12 of these were identified in the control sample and were also found in some of the other wine samples. The remaining 10 identified VCs were found in specific samples. Many of these VCs are commonly found in wines and are derived from grapes and yeast strain fermentation and the unification process [23]. The total identified VCs in wine samples varied from 92.07 \(\pm\) 0.34 to 96.91 \(\pm\) 0.63%. Ethanol, the predominant VC, exhibited statistically significant (_p_ < 0.05) variations across treatments, with PEF-1 and PEF-4 displaying the lowest concentration in the case of cherry wood chips and PEF-1 and PEF-3 displaying higher concentrations for apple wood chips. The observed variations in ethanol percentage are influenced by changes in the composition of other volatile compounds. Lower ethanol percentages may arise due to an increase in the percentage of other VCs, thereby affecting the overall composition. The increased ethanol percentages could contribute to alterations in the overall sensory profile of the wine, influencing mouthfeel and perceived sweetness. Acetic acid, a compound associated with acidity and volatile acidity in wines, was not detected in most samples, suggesting that the concentrations were below the detection limit. This absence may indicate that neither PEF treatment nor the use of different wood chip types significantly impacted the formation of acetic acid in Xinomavro red wine. The presence of 3-methyl-1-butanol, associated with alcohol and cheese odor (Table 3), exhibited variations across treatments, with PEF-3 showing higher concentrations for cherry wood chips and PEF-4 for apple wood chips. This observation suggests that specific PEF treatments may contribute to the enhanced extraction of this compound, influencing the aromatic profile of the wine. Certain compounds, such as 2-amino-4-methylbenzoic acid, were exclusively detected in apple wood chip samples. Hexanoic acid, a compound associated with fatty and fruity aromas, was not detected in most samples, indicating minimal impact from PEF and wood chip types. This suggests that the particular wood chip types and PEF treatments employed did not significantly influence the formation or extraction of hexanoic acid in Xinomavro red wine. Compounds such as 2-phenylethanol, contributing to floral and rose-like aromas, displayed variations across treatments, with PEF-2 and PEF-4 showing higher concentrations. Azulene and 4-ethylphenol were detected in higher concentrations in PEF-treated samples. These compounds contribute to the complexity of the wine's aroma profile and may result from the synergistic effects of PEF treatment and wood components. Apple wood chips, after 5 days, gave the higher percentage in 2,3-butanediol (significant at \(p<0.05\)). Additionally, 2-amino-4-methylbenzoic acid was only found in this procedure with the apple chips. After PEF-2 treatment, the higher percentage of VCs was shown using 2-phenylethanol (significant at \(p<0.05\)). High levels of thymol were also found in the PEF-1 and PEF-2 procedures. Without the PEF (blank sample), the ethyl caprylate was detected in similar amounts (not significant at \(p<0.05\)) to the PEF-4 procedure. In summary, the results from the HS-SPME/GC-MS analysis unveil the intricate impact of PEF treatment and different wood chip types on the chemical composition of Xinomavro red wine.