## 4 Conclusions  
GC \(\times\) GC-TOFMS was used to detect the dynamic aroma changes of SBT during manufacture, and a total of 241 volatile components was finally identified. (E)-\(\beta\)-ionone, (E,Z)-2,6-nonadienal, 1-octen-3-one, decanal, (Z)-4-heptenal, nonanal, and 2-methyl-butanol made significant contributions to the aroma profile of SBT due to their high roAVs. The OPLS-DA models of FL vs. S1, S1 vs. S2, S2 vs. S3, S3 vs. F, and F vs. D were established, respectively, and these models had good reliability. A total of 61 discriminatory volatile compounds (VIP \(>\) 1, \(p\)\(<\) 0.05, and 1 log\({}_{2}\)FC \(>\) 11) were screened out, of which 26 substances were shared in common among FL vs. S1, S1 vs. S2, and S2 vs. S3. The key components upregulated in the shaking stage were (Z)-3-hexenol, (Z)-hexanoic acid, 3-hexenyl ester, (E)-\(\beta\)-farnesene, and indole, which promoted the formation of the floral and fruity flavor of black tea. The volatile compounds in the fermentation stage were mainly fatty acids and amino acid degradation products and presented sweet, floral, and fruity flavor, which laid the material foundation for the formation of the flavor of black tea. The content of amino acid sources or the volatile components formed by the Maillard reaction in which they participated was significantly increased during the drying stage, and these components had a direct effect on the aroma quality of black tea. This study provides the dynamic changes of VOCs during SBT processing and the influence of processes on their changes, which is of great significance to improve the flavor quality of black tea and lay a solid foundation for the promotion of SBT production technology.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods11091228/s1](https://www.mdpi.com/article/10.3390/foods11091228/s1)]([https://www.mdpi.com/article/10.3390/foods11091228/s1](https://www.mdpi.com/article/10.3390/foods11091228/s1)), Table S1: Relative contents of the volatile compounds in shaken black tea samples during the manufacture based on GC \(\times\) GC-TOFMS; Table S2: Characterization of the volatile compounds in shaken black tea samples during the manufacture based on GC \(\times\) GC-TOFMS; Figure S1: (A1) permutation plot for the OPLS-DA model (FL vs. S1); (A2) permutation plot for the OPLS-DA model (S1 vs. S2); (A3) permutation plot for the OPLS-DA model (S3 vs. S2); (A4) permutation plot for the OPLS-DA model (S3 vs. F); (A5) permutation plot for the OPLS-DA model (F vs. D).  
Conceptualization, J.X. and H.J.; Methodology, W.W. ([PERSON]) and T.L.; Software, J.X. and W.W. ([PERSON]); Validation, P.L.; Formal Analysis, P.L.; Investigation, J.Y.; Resources, D.N.; Data Curation, J.X.; Writing--Original Draft Preparation, J.X.; Writing--Review and Editing, P.L. and H.J.; Visualization, J.X.; Supervision, J.Z.; Project Administration, H.J. and D.N.; Funding Acquisition, H.J. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the National Natural Science Foundation of China (Projects No. 31670692) and the Open Fund of Henan Key Laboratory of Tea Comprehensive Utilization in South Henan (Projects No. HNKLTOF2019006).  
Not applicable.  
Data Availability Statement: No new data were created or analyzed in this study. Data sharing is not applicable to this article.  
The authors declare no conflict of interest.