## 2 Results and Discussions
### Volatilomics and Molecular Networking Analysis
The distinct VOC compositions at each stage offer valuable insights into the fruit's market potential, enabling targeted applications based on flavor and aroma preferences. The heatmap in Figure 4 illustrates the clustering patterns of copoazu samples based on the concentrations of 66 significant VOCs (\(p\)-value > 0.05) at different ripening stages. According to the graph, fruits in the medium and overripe stages of ripening share more similarities, which makes them cluster. On the other hand, ripe fruits had a greater Euclidean distance, indicating a different composition of VOCs compared to the other ripening stages. During medium maturation, late stages of the biosynthetic metabolic pathways of VOCs may occur, that is, volatiles continue to be produced, whose principal function is to protect the growing organ against pathogens and predators [46]. Additionally, compounds present in the medium stage can act as precursors of molecules biosynthesized in the ripe stage, such as 3-methylbutyl alcohol, a precursor in the biosynthesis of esters such as 3-methylbutyl ethanoate [47]. In the overripe stage, alcohols such as 1,3-butanediol (20), 3-methylbutyl alcohol (119), 2-methylbutanol (27), 2-methylpropan-1-ol (7), 1-pentanol (31), 2-ethyl-1-butanol (53), 3-pentanol (14), and 1-penten-3-ol (11) were predominant. This observation is consistent with the report by [PERSON] et al. [48] that ethylene alters fruit metabolism, leading to a climacter respiratory rise that promotes the biosynthesis of alcoholic substrates that are later used to form esters. In addition, fruits emit alcohol in response to the stress caused by microorganisms or fermentation. For instance, when examarone grapes metabolize sugars and aliphatic acids, such as tartaric, citric, and malic acids, they generate 2,3-butanediol isomers that have fruity notes or a bread/banana aroma, depending on their levo or meso stereochemistry [49]. In contrast, the ripe stage of copoazu has a higher content of VOCs, particularly esters, which contribute significantly to its characteristic odor. Esterified compounds have been reported to be the most representative of the mature stage in strawberries [50] and purple passion fruit [51]. That is, in the mature stage of the copoazu, VOCs peaked at harvest. Esters can be divided into two groups: carboxylic acid derivatives such as 3-methylbutyl ethanoate (59), 2-methylbutyl ethanoate (61), premyl ethanoate (71), and ethyl butanoate (46), and fatty acid derivatives such as butyl ethanoate (47), ethyl hexanoate (89), butyl hexanoate (158), 3-methylbutyl hexanoate (166), and butyl butanoate (88), among others. Several of these esters are attributed to fruity, sweet, pineapple, apple, pear, and banana odors [52]. In addition, terpen such as \(\beta\)-_trans_-ocimene (101), \(\beta\)-_cis_-ocimene (105), and D-Limonene (99) were detected in the ripe stage, whereas 3-thujanone (117) and unknown (151) were found in the overripe stage. According to [PERSON] et al. [53], terpen undergo different enzymatic modifications, resulting in their vast chemical diversity. Also, [PERSON] et al. [12] suggested that variation in the volatile profile is related to the biosynthesis of terpenoids, which depends on the biosynthesis and cleavage of carotenoids. Finally, a molecular network of the volatile profile was constructed (Figure 5) to understand the biochemistry of VOCs in copoozu fruit during the three stages of maturation. The network consisted of clusters of compounds that were structurally related to spectral similarity. The network is composed mainly of seven families of compounds: esters (light green), alcohols and polyols (blue), monoterpenoids (green), dioxanes and dioxolanes (pink), carbonyl compounds (aldehydes, ketones, and acyloins) (light orange), and dicarboxylic acids and derivatives (red). These compounds are produced through various metabolic routes; fruits undergo biosynthesis to produce and emit regulated VOCs during development and ripening.