## Materials and Methods
### GC-MS Analysis  
Solid-phase microextraction conditions were as follows: 50/30 uM DVB/CAR/PDMS extraction fiber was used for sample extraction. The extraction head of the solid-phase microextractor was inserted into the sample bottle through the rubber pad on the bottle cap, and the fiber head was pushed out. Care was taken to ensure that the extraction head did not touch the fruit particles. Adsorption occurred at a constant temperature of 60 \({}^{\circ}\)C for 30 min, after which the fiber head was pulled back, and the extraction head was removed from the sample bottle. The extraction head was then quickly inserted into the gas chromatograph, the fiber head was pushed out, and the instrument was started to collect data. Analysis was conducted at 240 \({}^{\circ}\)C for 3 min, after which the fiber head was pulled back, and the extraction head was removed. GC conditions were as follows: An HP-INNOWAX capillary column was installed in the chromatograph (60 m \(\times\) 0.25 mm \(\times\) 0.25 um), which was procured from Agilent Technologies, Santa Clara, CA, USA. The column was initially programmed to a temperature of 50 \({}^{\circ}\)C, which was sustained for a duration of 1 min to stabilize the conditions. During subsequent operations, the temperature was raised progressively by 10 \({}^{\circ}\)C per minute until it reached 250 \({}^{\circ}\)C and a connection port temperature of 280 \({}^{\circ}\)C. Helium (99.999% purity), the main carrier gas during the study, was used and it was necessary to ensure that the flow rate was meticulously maintained at 1.0 mL/min throughout the process. The detector temperature, ion source temperature, and temperature of the quadrupoles rod were established at 270 \({}^{\circ}\)C, 230 \({}^{\circ}\)C, and 150 \({}^{\circ}\)C.  
Mass spectrometry relies heavily on the electron ionization (EI) mode, which requires that the ionization energy be set at a standard of 70 eV and that the operation be conducted at 230 \({}^{\circ}\)C. The mass spectrum was acquired through the use of the full scan mode, which \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
\begin{tabular}{c} **Cultivar** \\ **NO.** \\ \end{tabular} & **Cultivar Name** & **Maturity** \\ \hline
1 & Hongshou & Early & 20 & Jinxixiangjiaoli & Medium \\
2 & Livingzzahong & Early & 21 & Heibali & Medium \\
3 & Zaoli & Early & 22 & Suili 3 & Medium \\
4 & Jizaofeng & Early & 23 & Qiuji & Medium \\
5 & Dadanguo & Early & 24 & 98-1-6 & Medium \\
6 & Xiangjiaoli & Early & 25 & XY & Medium \\
7 & Hongsugine & Early & 26 & XY 7-2 & Medium \\
8 & [PERSON] & Early & 27 & XY 7-1 & Medium \\
9 & [PERSON] & Early & 28 & [PERSON] 2 & Late \\
10 & Taiyang & Early & 29 & [PERSON] 2 & Late \\
11 & Taoxingli & Early & 30 & [PERSON] & Late \\
12 & Aitianli & Early & 31 & Konglongdan & Late \\
13 & [PERSON] & Medium & 32 & [PERSON] & Late \\
14 & Huangganghe & Medium & 33 & Wanhuang & Late \\
15 & [PERSON] & Medium & 34 & Liwang & Late \\
16 & Hongxinli & Medium & 35 & Friar Plum & Late \\
17 & 10-27 & Medium & 36 & [PERSON] Early & Late \\
18 & Dahongpao & Medium & 37 & Great Rosa & Late \\
19 & Hongbayi & Medium & 38 & Fortune & Late \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Plum cultivar number, name, classification, and maturity of plum cultivars used in this work. encompassed an extensive scanning range extending from \(m/z\) 50 to 500. Supported by GC-MS analysis, total ion chromatograms were yielded and mapped in the study, utilizing the NIST 17 s database as a reference standard to identify and characterize the metabolites in the samples. Volatile compounds exhibiting a match of 90% or higher were retained for further analysis. Subsequently, the corresponding CAS registry numbers and retention times (RTs) of these compounds were professionally searched and meticulously queried. Each piece of data was derived from reliable results of experiments conducted in triplicate.