## 2 Results and Discussion  
The metabolic composition of peaches has been previously reported [25; 26], but none of the widely available research has made a differentiation between the compounds present in the whole fruit and those typical of the fruit pulp only. Thus, the current study follows such an approach for characterization. A total of 44 compounds were identified from the whole fruit and fruit pulp from the studied varieties (Table 1). Among them, amino acids, organic acids, sugar alcohols, saccharides, fatty acids, and phenolic acids were identified as existing groups. Sometimes, the use of diverse experimental approaches leaves researchers challenged when comparison of data should be applied. Organic acids are generally important to the specific tastes of fruits due to the sourness and acidity they provide [27]. The eight studied varieties ranged in terms of shikimic acid, malic acid, citric acid, quinic acid, and succinic acid, with the WF having higher levels compared to the FP. The primal organic acid in all samples (FP and WF) was shikimic acid, while the least present was L-ascorbic acid. Shikimic acid has been previously reported as most present in peach varieties [28]. Similarly, malic acid, citric acid, quinic acid, and succinic acid are regularly reported as the dominant ones [29; 30; 31]. Phenolic compounds are considered to be widely distributed in plants [32]. The current results (Table 1) reveal the presence of six phenolic acids, while only one of the varieties (\"July Lady\") lacked p-coumaric acid. Studies acknowledge the importance of phenolic acids due to their biological functions [33]. Here, once more the whole fruit sample is found to be richer in phenolic acids compared to the fruit pulp. This proves that the fruit skin should be an object of research and consumed where appropriate due to its ability to accumulate health-contributing compounds. Protocatechuic acid, chlorogenic acid, and caffe acid are most present in the WF and FP of the \"Gergana\" variety, p-coumaric acid and sinapic acid in the \"Filina\", and ferulic acid in the \"Flat Queen\". By default, chlorogenic acid is reported as the most abundant in plant samples [34], which is further supported by the current results. Chlorogenic acid is reported as a possible preventive of cardiovascular disease [35]. The amount of amino acids established in the current study reveals that peaches cannot be considered protein contributors in the daily diet. A total of 18 amino acids have been identified in the peach varieties object of analysis. From all studied samples, the two nectarine varieties (\"Gergana\" and \"Morsiani 90\") are the only ones that contain all essential amino acids in even limited quantities. Aspartic acid is the least detected in all samples. The same trend as for other compounds, where the WF is richer than the FP, is observed for the amino acids. In accordance with earlier studies [36], linoleic acid is reported as one of the most abundant fatty acids. Other fatty acids (FA) found in greater quantities are the palmitic, oleic, and stearic acids. The WF samples are documented as richer in FAs compared to the FP ones. The \"Laskava\", \"July Lady\", and \"Morsiani 90\" varieties hold the most FAs compared to the other studied varieties. There is a predominance of long-chain saturated fatty acids and the presence of more PUFA compared to MUFA. Based on existing reports [37; 38], these findings hint at the possibility of more profound studies on the topic of the possible health effects of the fatty acid content in peaches. The investigated volatile compositions of both peach fruit and fruit pulp from eight peach cultivars are presented in Table 2. In total, 65 compounds were profiled after an HS-SPME-GC-MS analysis: 16 esters, 14 aldehydes, 5 alcohols, 7 hydrocarbons, 7 ketones, 8 acids, and 8 terpen. The highest content of volatile compounds was attributed to the \"Morsiani 90\" variety (Table 2) (both pulp and whole fruit), while the lowest belonged to the \"Uto 4\" (whole fruit) and \"July Lady\" (fruit pulp).