# Discrimination of Smoke-Exposed Pinot Noir Wines by Volatile Phenols and Volatile Phenol-Glycosides
## 4 Summary  
The free form and total volatile phenols and their glycosides in smoke-exposed and non-smoke-exposed Pinot nor were analyzed by SPME-GC-MS and HPLC-HR-MS/MS. Results showed that smoke exposure significantly increases the concentration of VPs and glycosides in wine, which is well separated from non-smoke exposure wines by a heating map and PCA analysis. Moreover, fifteen VP-glycosides identified were much higher in smoke-exposed wines, strongly correlated with each other and with free and total VPs, suggesting a coordinated regulation of these compounds in response to smoke exposure. The findings inform future efforts to mitigate the adverse effects of smoke exposure on wine quality. However, further structural characterization is advised to ensure a complete assessment of the presence of VP-glycosides.  
Figure 5: The fragmentation pathway (color-coded) is an example of using the MS/MS data for level 2 annotations. (**a**) Extracted ion chromatogram \(m/z\) 609.2. (**b**) Proposed fragmentation pattern for Hexose-Hexose-Pentose-4-Ethylguaiacol; the dotted lines represent the sequential fragmentation. (**c**) Spectra acquired for \(m/z\) 609.2 using a collision energy of 40 V.  
**Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/molecules30132719/s1](https://www.mdpi.com/article/10.3390/molecules30132719/s1)]([https://www.mdpi.com/article/10.3390/molecules30132719/s1](https://www.mdpi.com/article/10.3390/molecules30132719/s1)), Table S1. Standard curves for free and total volatile phenol analysis by HS-SPME-GC-MS. Table S2. Concentrations of volatile phenols analyzed by SPME-GC-MS. Table S3. Thirty-five tentative annotated glycosides (level 2 annotations) identified from non-smoke-exposed and smoke-exposed wines. Table S4. Correlation matrix for VPs and VP-glycosides in non-smoke-exposed and smoke-exposed wines with Pearson's correlation analysis.  
**Author Contributions:** A.A.-M.: Data curation, formal analysis, investigation, methodology, software, validation, original draft. R.Y.: Data curation, formal analysis, investigation, validation, original draft. M.C.Q.: Conceptualization, methodology, project administration, resources, supervision, validation, visualization, review and editing. Y.L.Q.: Conceptualization, data curation, formal analysis, investigation, methodology, project administration, supervision, validation, visualization, intensive review, and editing. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.  
**Acknowledgments:** The authors thank the Oregon winemakers and grape growers for providing wine samples. In addition, the China Scholarship Council (#201906170269) partially supported [PERSON]'s study at Oregon State University.  
**Conflicts of Interest:** The authors declare that no research funding was received for the study and that there are no competing financial interests.