## 2 Results and Discussion
Alcohols, on the other hand, were the least found in all samples. Previous research on the WFs of peach varieties has established a similar trend in the results [2]. Analogous compound groups have also been identified in a recent study of famous Chinese peach cultivars [40]. Figure 1: _Cont._  
Considering their abundance, the most important aldehydes for the WF and FP are (E)-2-hexenal, hexanal, heptanal, and nonanal. Contrary to the current results, benzaldehyde was identified as a major aldehyde contributor in a study of American peach cultivars [3]. Heptanal has its highest quantity in the early-ripening variety \"Filina\". Hexanal and (E)-2-hexenal are compounds which are associated with the maturation process, and their quantities are lower in the FPs of all studied varieties. Hexanal was found to be naturally occurring within the fruit and is considered important for the volatile profile of nectaries, in particular [41]. Its %TIC in the two studied nectarine varieties is rather similar, even though the ripening period is different. Both hexanal and E-2-hexenal are also regularly identified in apple cultivars and are associated with a specific leafy-sweet odor [42]. Figure 1: Distribution of volatile compounds ((**A**)—WF, (**B**)—FP) and metabolites ((**C**)—WF, (**D**)—FP) according to their chemical families in eight peach cultivars. According to other research, the acid content in peaches is rather low [43]. The most dominant acids in the investigated peach whole fruits and pulps are dodecanoic acid and nonanoic acid. Ketones come in relatively low amounts, with \(\gamma\)-octalactone and \(\gamma\)-dodecalactone being the most abundant. Lactones are usually isolated in peach volatiles, and they are flavor-contributing [26]. Lactones are also linked to a specific peach-like odor and flavor [44]. According to the established results, the \"Ufo 4\" and \"July Lady\" should exhibit the most distinct peach-associated aroma. It should also be mentioned that the fruit pulp contains more lactones compared to the whole fruit. \(\Gamma\)-Dodecalactone is also a major lactone isolated in other research [3]. Lactones, particularly delta-lactones, are as well implicated in the peach aroma. Recently, benzaldehyde, linalool, and C\({}_{10}\) lactones were found to increase in the final period of peach ripening, while C\({}_{6}\) aldehydes decreased [2,45]. A total of five alcohols were Identified in all studied samples. The relative cumulative alcohol content ranged from 2.69 %TIC (\"Filina\", WF) to 6.73 %TIC (\"Evmolipidya\", FP). The highest alcohol content is found in the \"Evmolipidya\" variety, in both the WF and FP. The content of benzyl alcohol, which is a natural component in peaches [46], gradually increases for the varieties that ripen in the months of July and August and then decreases in the late-ripening \"Flat Queen\" and \"Evmolipidya\" varieties. The \"Morsiani 90\" does not fall into this trend, as it is the latest ripening (mid-September) variety used in this study, and a steady increase in its benzyl alcohol content is registered. This may suggest that not only the ripening period, but the cultivar as well contributes to the volatile peculiarities of each variety. Esters contributed largely to the overall volatile components identified in this study. Moreover, the most abundant esters (average content >3.00%TIC) as determined by GC-MS were ethyl tidate, ethyl hexanoate, ethyl benzoate, and 2-phenyl ethyl butanoate. Methyl decanoate and benzyl butanoate were present in relatively low amounts (average content <1.5% TIC) in the FPs of each variety. Consistent with previous reports [47,48], ethyl tidate was the most abundant in most of the WFs of the cultivars analyzed in this study. The estimated amount of terpen identified in the studied peach varieties is less than that estimated in the peach cultivar \"Cresthaven\" grafted onto five different roostocks [49]. However, a resemblance in the compounds found in the highest quantities (limonene, linalool, and ocimene) is visible.