## 5 Conclusions  
In this study, a total of 72 volatile compounds and 59 non-volatile compounds were identified and quantified using GC-TOF-MS and GC-MS, respectively. Recombination experiments successfully replicated the characteristic aroma profile of strong-aroma baijiu, validating the comprehensive contribution of these compounds. Aroma omission tests revealed that the absence of non-volatile organic acids significantly diminished sour and fruity notes while slightly intensifying alcoholic pupency. Further subdivision of organic acids into monobasic and dibasic categories indicated that monobasic acids primarily enhanced the acidic and fruity aromas, whereas dibasic acids slightly mitigate the alcoholic aroma, suggesting their role in harmonizing and masking undesirable sensory attributes.  
This research not only comprehensively analyzed the volatile and non-volatile components of strong-aroma baijiu but also elucidated their critical roles in flavor formation. These findings provide a scientific foundation for quality control and product innovation in the baijiu industry, particularly regarding the role of non-volatile compounds in modulating aroma complexity and balance. However, this study only discusses the odor, and the mechanism of the impact of these non-volatile compounds on the aroma of baijiu needs further research.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods14142490/s1](https://www.mdpi.com/article/10.3390/foods14142490/s1)]([https://www.mdpi.com/article/10.3390/foods14142490/s1](https://www.mdpi.com/article/10.3390/foods14142490/s1)), Table S1. Quantitative information of 72 volatile compounds in different strong aroma Baijiu (\(\upmu\)g/L); Table S2. Qualitative and quantitative of 59 non-volatile compounds in different strong aroma Baijiu (\(\upmu\)g/L).  
Conceptualization, F.Y. and J.Z.; methodology, Y.Z.; software, Y.Z.; validation, F.Y., Y.Z. and S.P.; formal analysis, Y.W. and Y.Z.; investigation, Y.W.; resources, X.X.; data curation, Y.Z.; writing--original draft preparation, Y.Z.; writing--review and editing, F.Y.; visualization, Y.Z.; supervision, F.Y.; project administration, F.Y.; funding acquisition, F.Y. All authors have read and agreed to the published version of the manuscript.  
The Key Laboratory of Wuliangye-flavor Liquor Solid-state Fermentation, China National Light Industry, grant number 2022 JJ008.  
The study was conducted in accordance with the Declaration of Helsinki. The study was approved by the HZAU Institutional Review Board, (HZAUHU-2023-0018, 16 March 2023).  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.  
[PERSON] was employed by the Wuliangye Yibin Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.  
The following abbreviations are used in this manuscript:  
GC-MS/O Gas chromatography-mass spectrometry/olfactometry GC-TOF-MS Gas chromatography-time of flight-mass spectrometry BSTFA Bis(trimethylsilyl)trifluoroacetamide RI Retention index SPME Solid-phase microextraction IS Internal standard ANOVA Analysis of variance PCA Principal component analysis PLS-DA Partial least squares discriminant analysis OAV Odor activity value QDA Quantitative descriptive analysis