## 1 Introduction
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Number of Identified VOCs** & **Technique** & **Number of Cultivars** & **Year of Publication** & **Literature** \\ \hline
498 & HS GC-MS & 1 & 2004 & [8] \\
33 & HS GC-MS & 1 & 2006 & [11] \\
30 & HS & 1 & 2007 & [12] \\
100 & SPME GC-MS & 3 & 2009 & [13] \\
72 & SPME GC-MS & 18 & 2012 & [14] \\
399 & SPME GC/GC-MS & 1 & 2012 & [10] \\
69 & SPE GC-MS/MS & 5 & 2014 & [15] \\
118 & HS-SPME GC-MS & 42 & 2017 & [2] \\
95 & SPME GC-MS & 17 & 2017 & [6] \\
78 & HS-SPME GC-MS & 40 & 2021 & [9] \\
39 & HS-SPME GC-MS & 35 & 2022 & [16] \\
119 & HS-SPME GC/GC-MS & 37 & \multicolumn{2}{c}{Current study} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Insight through selected publications on apple VOCs. Numerous studies indicate significant differences in the VOC profiles between varieties [2; 9; 14; 16]. Therefore, in this study, we did not use fingerprinting to differentiate varieties as was shown in the literature [19; 20]. The aim of our analyses was to check if it is possible to fingerprint apple cultivars grouped according to the same varieties by their VOC profile. The genetic background is indicated as the most important factor responsible for the differences in chemical composition [4; 21]. However, it is noteworthy that many other factors, such as production region, climatic, atmospheric, and soil conditions [22], orchard management practices [23], or even the harvesting method [24], also play an important role. The subject of this study was 37 old and new apple varieties, both from one germplasm and from different orchards, which gave a total of 87 individual samples. Since fingerprinting from the available literature focused on demonstrating differences between varieties, we decided to check whether it was possible to demonstrate similarities within varieties originating from different areas. \begin{table}
\begin{tabular}{c c c c} \hline  & **Compound** & **Flavor** & **Odor Detection Threshold [ppb]** \\ \hline \multirow{4}{*}{Aldehydes} & Acetaldehyde & pungent, fresh, aldehyde, & 15–120 \\  & & refreshing, green & 15–120 \\  & 2-Hexenal & sweet, almond, fruity, green, leafy, & 17 \\  & Hexanal & apple, plum, vegetable & 17 \\  & Hexanal & green, woody, vegetative, apple, & 4.5–5 \\  & & grassy, citrus & 4.5–5 \\ \hline \multirow{4}{*}{Alcohols} & Butanol & oily, sweet, balsamic & 500 \\  & Hexanol & green, herbaceous, woody, sweet & 2500 \\  & 2-Hexenol & sharp, green, leafy, fruity, unripe & 70 \\  & & banana & \\ \hline \multirow{4}{*}{Alcohols} & Butyl acetate & sharp, ethereal, fruity, banana, & 2 \\  & Pentyl acetate & ethereal, fruity, banana, pear, apple & 15 \\  & Hexyl acetate & fruity, green, apple, banana, sweet & 2 \\  & 2-Methylbutyl acetate & sweet, banana, fruity, ripe, estery, & 22 \\  & Ethyl butyrate & strong, ethereal, fruity, banana, & 1 \\  & pineapple & & \\  & Ethyl 2-methylbutyrate & fruity, fresh, berry, grape, pineapple, & 0.1–0.3 \\  & Estragole & sweet, phenolic, anise, harsh, spice, & 10 \\  & & green, herbal, minty & \\  & Methyl 2-methylbutyrate & ethereal, fruity, green, sweet & 0.25 \\ Esters & Propyl 2-methylbutyrate & winey, fruity, apple, pineapple & 7 \\  & Butyl 2-methylbutyrate & fruity, tropical, green, ethereal, & 17 \\  & herbal, celery, cocoa, peach, grassy & & 22 \\  & Hexyl 2-methylbutyrate & green, waxy, fruity, apple, banana, & 22 \\  & & woody & \\  & Butyl hexanoate & fruity, pineapple, berry, apple, juicy, & 250 \\  & Hexyl propanoate & pear, green, fruity, musty, rotting & 8 \\  & Butyl butyrate & fruity, banana, pineapple, green, & 100 \\  & cherry, tropical, ripe fruit & & \\  & fruity, sweet, banana, tropical, & 25–200 \\  & & tutti-fruti & \\  & Hexyl butanoate & green, sweet, fruity, apple, waxy & 250 \\  & Hexyl hexanoate & green, sweet, waxy, fruity, tropical, & unknown \\  & & berry & \\ \hline \end{tabular}
\end{table} 
Table 2: The most important organic volatile compounds that have a significant impact on the aroma of apples [17; 18].