## Results and Discussion
### Volatile Organic Compounds  
Natural volatile organic compounds (VOC) play an important role in the aromatic component of tomato flavor. VOCs identified and quantified in PdP and CIL were grouped into 4 different classes, including aldehydes, alcohols, ketones and organic acids (Table 5). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample** & **Malic Acid** & **Citric Acid** & **Succin Acid** & **Oxalic Acid** & **Glutamic Acid** & **Ascorbic Acid** \\ \hline PdP **0** & 580.48 \({}^{\pm}\) 6.88 & 441.66 \({}^{\pm}\) 0.03 & 54.38 \({}^{\pm}\) 3.70 & 8.95 \({}^{\circ}\) \(\pm\) 0.56 & 826.45 \({}^{\pm}\) 11.52 & 11.28 \({}^{\pm}\) 0.76 \\ PdP **6** & 492.62 \({}^{\pm}\) 3.89 & 404.14 \({}^{\circ}\) 2.02 & 25.65 \({}^{\pm}\) 1.12 & 3.00 \({}^{\pm}\) 0.69 & 830.47 \({}^{\pm}\) 9.39 & 9.78 \({}^{\pm}\) 0.96 \\ CIL **0** & 655.58 \({}^{\pm}\) 1.11 & 557.60 \({}^{\pm}\) 1.26 & 16.21 \({}^{\pm}\) 7.30 & 25.05 \({}^{\pm}\) 0.33 & 349.60 \({}^{\pm}\) 2.28 & 15.50 \({}^{\pm}\) 0.33 \\ CIL **1** & 108.91 \({}^{\pm}\) 1.43 & 811.51 \({}^{\pm}\) 9.17 & 48.54 \({}^{\pm}\) 3.34 & 49.90 \({}^{\pm}\) 0.04 & 629.60 \({}^{\pm}\) 11.62 & 9.2 \({}^{\pm}\) 0.48 \\ \hline \hline \end{tabular}  
* a-d: different letters in the same column correspond to significant differences (\(p\) \(<\) 0.05).  
\end{table} 
Table 4: Mean and standard deviation of organic acids (mg/100 g fresh weight) content. Aldehydes were the most abundant VOC found in the two tomato varieties under investigation, and hexanal was the most abundant compound in both PdP and CIL at all times during the storage period (i.e., 55.79 and 100.22 mg/kg for PdP and 57.22 and 25.90 mg/kg for CIL, respectively). Additionally, important concentrations of heptanal and 2-hexanal have been detected. These are known as \"green compounds\", as they impart a fresh, green character to the tomato aroma [37]. According to other authors [38] the main precursors of hexanal in tomato are leucine and \(\beta\) caroten and the main precursors of 2-hexanal are 2-isobutylthiazole and 6-methyl-5-hepten-2-one. Considering the alcohols fraction in the control PdP sample, 1-hexanol was determined at 44.80 mg/kg and decreased to 9.13 mg/kg (80%) after 6 months storage. The concentration of this alcohol in CIL at both storage period ranged from 7.27 to 6.43 mg/kg, respectively. 1-Hexanol is a volatile compound derived from lipids via oxidation when cells are disrupted (like hexanal), and it imparts a mint flavour in tomatoes [39]. The main ketone present at the highest concentration was 6-methyl-5-hepten-2-one (i.e., 1.25 and 3.38 mg/kg in CIL0 and CIL1, respectively). This compound is a carotenoid-related compound and has a tomato-like flavour, musty aroma and fruity taste [39]. The last noticeable aspect of VOC in PdP and CIL is that PdP is characterized by a large concentration of 2-isobutylthiazole (i.e., 29.44 mg/kg). This compound is one of the most well-known thiazols and has a strong green odour that resemble tomato leaves, and it is considered fundamental in the development of proper tomato flavour [40]. A deep look at the results in Table 5 reveals that there is not clear correlation between the variation of VOCs and the storage time for both varieties. In some cases, specific volatile compounds, such as aldehydes, increased with storage in PdP, while in the cases of CIL, the same compounds decreased with storage.