## 2 Results and Discussion
### Polyphenolic Compounds Analysis by HPLC Supported by FTIR and Confocal Microscopy
#### 2.1.5 Volatile Compounds Content  
Apart from the quantitative analysis of phenolic compounds, combined with a FTIR and microscopic analysis, this study also focused on the composition of volatile compounds (VOCs) in the examined wine samples. The adoption of a low threshold signal-to-noise ratio led to the identification of a relatively high number of chromatographic peaks, enabling the detection of trace compounds. The implementation of the GC \(\times\) TOFMS technique and the peak deconvolution algorithm facilitated the tentative identification of 41 VOCs in persimmon wine, 47 VOCs in pomeranate wines, and 73 VOCs in kiwi wine, representing several chemical classes. A detailed composition of these volatile fraction compounds is gathered in the Supplementary Materials in Tables S1-S3 for pomeranate, kiwi, and persimmon wines, respectively. It was decided to present the top 10 abundant VOCs found in the volatile fraction of fruit wines in Figure 4A-C.  
Figure 3: Scanning electron microscopy of freeze-dried (**A**) pomeranate wine, (**B**) kiwi wine, and (**C**) persimmon wine.  
Butanedioic acid, diethyl ester, is a compound identified in all the examined wine samples, is primarily produced during the fermentation process when yeast metabolizes sugars. It contributes to a fruity aroma, enhancing the complexity and balance of a wine's bouquet. This ester's higher concentrations may particularly impart a unique fruity character to wines made from grapes grown in regions known for their volcanic soil, such as those in Yarden-type wines, contributing to distinctive characteristics known for their complexity, depth, and aging potential compared to fruits wines. The impact of the compound on wine quality is influenced by its interaction with other compounds in the wine, highlighting the need for further sensory analysis to fully understand its role. In all the evaluated fruit wines, ethyl acetate emerged as one of the most significant compounds, ranking third, fourth, and eighth in persimmon, pomeranate, and kiwi wines, respectively. This volatile compound is associated with sensory descriptors such as anise, ether, and pineapple perception. Additionally, decanoic acid, noted in ninth position in pomeranate wine,  
Figure 4: The top 10 abundant volatile compounds in fruit wines: (**A**)-pomeranate wine, (**B**)-kiwifruit wine, and (**C**)-persimmon wine.  
contributes to fatty and citrus impressions. Although present in persimmon and kiwi wines, it appeared in the 19 th and 26 th positions, respectively. Pomegranate wines also exhibited the presence of nonanal (fruit, grape, citrus, and rose) and octanoic acid (oily), as reported by [PERSON] et al. [28]. Our findings regarding the VOCs in pomegranate wines are consistent with those of [PERSON] et al. [28], who observed distinct volatile profiles characterized by a prevalence of ethyl octanoate. Additionally, varietal differences were noted in the relative abundance of alcohols, terpen, aldehydes, esters, and organic acids, impacting sensory aspects such as odor, flavor, and color. [PERSON] et al. [24] indicated that kiwi wine typically contains small amounts of aromatic components. [PERSON] et al. [29] noted a higher impact of methanol on the aroma; however, we did not detect methanol in our samples, which is consistent with the findings of [PERSON] et al. [24]. The aroma of persimmon wine is primarily derived from the persimmon fruit [15]. Additionally, higher alcohols formed during fermentation contribute to the desirable aroma of the wine. [PERSON] et al. [15] noted that isoamyl alcohol and phenylethyl alcohol were the major higher alcohols. Esters, which contribute to the fruity aroma and sensory character of wines, include acetic acid 2-phenylethyl ester, decanoic acid ethyl ester, and 1-butanol-3-methyl-acetate.