## 4 Conclusions  
_S. cerevisiae_ was a critical factor influencing the flavor quality of the fermented fruit alcoholic beverage. This study used GC-E-Nose, GC-MS, and GC-IMS techniques to characterize the VOCs in the GAB fermented by four different _S. cerevisiae_ strains. Combining these three methods compensated for their limitations, providing a more comprehensive understanding of VOC differences across fermentation groups. GC-E-Nose, combined with DFA, showed significant flavor differences in the GAB samples fermented by the four strains. A total of 171 VOCs were identified using GC-MS and GC-IMS, with 98 VOCs detected only by GC-MS, 60 exclusively by GC-IMS, and 13 by both methods. GC-MS identified more VOCs, supplying extensive flavor information for the GAB, while GC-IMS was more sensitive in detecting trace compounds, especially aldehydes like hexanal, propanal, and \(\beta\)-cyclocitral, which were identified exclusively by GC-IMS.  
Using PLS-DA and VIP values, nine aroma compounds (VIP \(>\) 1.5) were selected as potential markers, with ethyl esters (such as ethyl myristate, 2-lauric acid methyl ester, ethyl octanoate, ethyl linoleate, ethyl laurate, ethyl valerate, phenylethyl acetate, and ethyl nonanoate) playing a dominant role in differentiating aroma profiles among the fermentation groups. Additionally, OAV analysis identified 13 aroma compounds with OAV \(\geq\) 1, including \(\beta\)-ionone and ethyl octanoate as representative aroma compounds of the GAB, both of which contributed to a strong floral and fruity aroma and were most abundant in the SY fermentation group. Notably, ethyl octanoate emerged as both a potential marker for distinguishing aroma variations in the GAB fermented by different _S. cerevisiae_ strains and as an important contributor to the overall aroma of the GAB.  
Combined with the sensory evaluation, the analysis indicated that the SY fermentation group exhibited a more distinctive flavor profile. These findings provided a useful basis for studying aroma differences in the GAB fermented by different _S. cerevisiae_ strains and offered theoretical guidance for selecting _S. cerevisiae_ strains in the industrial production of the GAB.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods13243984/s1](https://www.mdpi.com/article/10.3390/foods13243984/s1)]([https://www.mdpi.com/article/10.3390/foods13243984/s1](https://www.mdpi.com/article/10.3390/foods13243984/s1)), Table S1: Volatile components determined by GC-IMS in GAB fermented by different _Saccharomyces cerevisiae_ strains; Table S2: Presents the odor activity values (OAV \(\geq\) 1) for GAB fermented by different _Saccharomyces cerevisiae_ strains.  
Conceptualization, investigation, methodology, writing--original draft preparation, Z.S.; methodology, W.L.; formal analysis, Z.C. and Z.P.; data curation, M.M. and J.Z.; writing--review and editing, G.X. and J.L.; funding acquisition, D.W. All authors have read and agreed to the published version of the manuscript.  
This study was supported by the Program of Introducing Talents of Discipline to Universities (111 Project) (111-2-06) and the Key Project of Research and Development Plan of Ningxia (2020 BFH02005).  
Not applicable.  
The participants for the sensory evaluation of the GAB were selected from a pool of trained evaluators who volunteered to perform the sensory tests. All participants were informed in advance about the purpose and procedure of the experiment and agreed in writing to participate voluntarily in the sensory analysis. Participants could withdraw from the test at any time. The participants were in good health and no allergies to the ingredients were detected.  
The original contributions presented in the study are included in the article/Supplementary Material; further inquiries can be directed to the corresponding authors.  
The authors declare that they have no competing interests.