## 4 Conclusions  
The aroma sensory attributes and volatile substances of seven green huajiao samples from the Sichuan and Chongqing regions were investigated in this study. In addition, the key aroma components that mainly contribute to the aroma sensory attributes of the different huajiao samples were studied. Compared to red huajiao, there are obvious differences in the aroma characteristics of green huajiao. The green samples from the Sichuan and Chongqing regions have different sensory properties and key flavor components. The aroma compounds of linalool, ocimene, myrcene, \(\beta\)-pinene, limonene and gamma-terpinene are the key aroma components to distinguish the samples from different areas of Sichuan and Chongqing. By studying the flavor characteristics of green huajiao in Sichuan and Chongqing, the differences in flavor of green huajiao samples from different origins were analyzed, and the correlation between green huajiao and physical and chemical substances was further explored. These results were useful and necessary for understanding the quality differences between different varieties of green huajiao in Sichuan and Chongqing and for characterizing the aroma traits between the varieties. The results of this study provide a theoretical foundation and basic aroma quality data on flavor quality for the development of the green huajiao industry and promote the local characteristic agricultural products industry and rural revitalization.  
**Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods13060836/s1](https://www.mdpi.com/article/10.3390/foods13060836/s1)]([https://www.mdpi.com/article/10.3390/foods13060836/s1](https://www.mdpi.com/article/10.3390/foods13060836/s1)), Figure S1: Representative GC chromatograms of green huajiao sample; Table S1: Target gas flow and dilution ratio for dilution levels; Table S2: A single concentration of each major component in green huajiao; Table S3: Odor thresholds and aroma descriptions of key aroma substances.  
**Author Contributions:** Conceptualization, L.G. and K.Z.; methodology, L.G. and K.Z.; software, H.W.; validation, L.Z., L.G. and K.Z.; formal analysis, L.Z.; investigation, L.G.; resources, H.W.; data curation, L.G., K.Z. and Y.X.; writing--original draft preparation, L.G.; writing--review and editing, K.Z.; visualization, L.G. and K.Z.; supervision, K.Z.; project administration, B.S.; funding acquisition, B.S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by National Key R&D Program of China (2023 YFF1104700), Science, Special Fundamental Research Fund for the Central Public Scientific Research Institutes (562022Y-9417) and Technology Program of China State Administration for Market Regulation (2023 MK186).  
**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the Ethics Committee of Tsinghua University (Approved date: 12 January 2022).  
**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.  
**Data Availability Statement:** The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
Conflicts of Interest: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.