## 3 Results and Discussion
### VOC Flavor Profile of Carbonated Lemon Drink  
The volatile composition of carbonated lemon drink is shown in Table 3. All compounds were detected with a higher than 71% probability and a match factor score greater than 700. The MS spectra of the identified compounds are presented in Figure S4. Terpenes/terpenoids detected by gas chromatography were (+)-Sabinene (rt = 10.916;  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Peak No.** & **RT (min)** & **Compound** & **CAS No.** & **Probability (\%)** & **Flavor/Fragrance** \\ \hline
1 & 4.429 & Pentyl acetate & 628-63-7 & 70.3 & Banana/apple \\
2 & 7.898 & Ethyl butyrate & 105-54-4 & 78.0 & Pineapple \\
3 & 9.449 & Isopentyl acetate & 123-92-2 & 80.0 & Banana/pear \\
4 & 11.928 & 1-Methylcyclopentene & 693-89-0 & 70.1 & - \\
5 & 12.607 & Pentyl butyrate & 540-18-1 & 67.7 & Banana/apricot \\
6 & 12.756 & \(\alpha\)-Terpineol & 586-62-9 & 72.6 & Pine/woody \\
7 & 13.839 & (+)-\(\alpha\)-Pinene & 80-56-8 & 74.7 & Citrus/spicy \\ \hline \end{tabular}
\end{table}
Table 2: VOCs identified in the commercial tea.  
(+)-Sabinene and its homologous alcohol (cis-Sabinene hydrate) belong to the class of bicyclic monoterpenes. These compounds have a very hydrophobic molecule, insoluble in water. They are often found in sage (Salvia verbenaca), nutmeg (Myristica fragrans), sweet marjoram, and spearmint. There are many studies in the literature regarding detecting and quantifying (+)-sabinene and cis-sabinene hydrate, especially in essential oils. The main field of application is aromat therapy [34; 35; 36].  
Limonene presents an aromatic profile based on citrus and bitter notes. The primary botanical sources are citrus fruits, piney, rosemary, mint, fennel, and cannabis. According to the studies published so far, due to its pharmacological properties (antimicrobial, antioxidant), limonene is used as a flavoring compound in the food and beverage industry [11]. \(\gamma\)-terpinene, or 1,4-p-mentadiene, is an isoprenoid with a strong lemon smell and herbal taste. The GC-MS technique detected \(\gamma\)-terpinene in the leaves of Origanum vulgare [37] and citrus fruits, where the recovery percentage was 3-5% [38]. Besides its role as a flavoring agent, \(\gamma\)-terpinene has an antioxidant effect, making it an ideal candidate in medicine [39]. \(\gamma\)-terpinene has also been detected, but not quantified, in several different fruits and herbs, such as evergreen blackberries (_Rubus laciniatus_), saffron (_Crocus sativus_), and pepper (spice).  
Natural sources in which 3-carene was identified are mango fruits and cannabis leaves. It is a monoterpene soluble in oils and fats and, similar to limonene, and has the same fruity notes--citrus and sweet. Published studies confirm through GC-MS analysis the presence of 3-carene in some alcoholic beverages, which was proven to be the dominant terpene compound [40].  
The woody aroma, specific to a-terpineol, was also identified in the samples of commercial tea. P-Cyrene is a compound from the class of aromatic compounds with a structure similar to monoterpenes, with a typical lemon aroma. It is a constituent of many essential oils, including cumin and thyme. GC-MS/MS quantitatively detected p-cymene in different parts of Eupatorium fortune [15]. Although p-cymene is the only natural geometric isomer, several methods have been scientifically published for preparing these isomers: 1) dehydrogenation of limonene produces p-cymene; dehydrogenation of 3-carene produces a mixture of p- and m-cymene [41].