## 4 Conclusions  
In this study, we used SPME-GC-MS combined with sensory evaluation to examine the association between consumer perception and volatile compounds of six types of Chinese vinegar. The results showed that 52 volatile compounds were detected by GC-MS in six types of Chinese vinegar. High concentrations of ethyl acetate, acetic acid, and phenethyl alcohol were found in all the vinegar samples. Combined with sensory evaluation, it was found that some specific volatile compounds affected consumer liking for Chinese vinegar significantly. The potato vinegar (B6) was preferred; more consumers described B6 as \"having a sweet aroma and fruity vinegar aroma\" than the other samples, and many consumers described the Heng-shun Jinyou balsamic vinegar (B5) as exhibiting a \"too pungent vinegar aroma\" when asked what they disliked about the product. For PLSR, the most important volatile compounds in the three clusters that drove consumer liking confirmed the importance of 1-methylpyrrole-2-carboxaldehyde, ethyl acetate, acetylfuran, 1H-Pyrrole-2-carbaldehyde, 2,3,5-trimethlypyrazine, benzaldehyde, phenylethanol, 3-methyl-1-butanol, 3-hydroxy-2-butanone, (2-methoxy-4-vinyl-phenyl)-acetate, 1,2-propanediol,2-acetate, isobutyl acetate, methylbutyric acid, and isoamyl acetate in Chinese vinegar. Manufacturers should pay attention to the changes in these 14 compounds and the content of the end product in the production process, and at the same time accumulate data about the correlation between compounds and consumer liking. They should subsequently change the production process using the data to improve the quality and consumer preference of vinegar. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Cluster 1** & **Relative Importance** & **Cluster 2** & **Relative Importance** & **Cluster 3** & **Relative Importance** \\ \hline
1-methylpyrrole-2-carboxaldehyde & 4.342935 & benzaldehyde & 7.217879 &
\begin{tabular}{c} 4-acetoxy-3- \\ methoxystyrene \\ \end{tabular} & 8.302227 \\ ethyl acetate & 4.319396 & phenylethanol & 4.1944 & 1,2-propanediol,2-acetate & 8.09123 \\ acetylfuran & 4.269728 & 3-methyl-1-butanol & 4.082279 & isobutyl acetate & 3.474666 \\ carbaldehyde & 3.784573 & 3-hydroxy-2-butanone & 3.887411 & 2-methylbutyric acid & 3.007397 \\
2,3,5-trimethylpyrazine & 3.509161 & ethyl acetate & 3.391669 & isoamyl acetate & 2.51753 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: The relative importance of the top five most important volatiles in three clusters. Figure 8: The biplot of each cluster (**a–c**) by partial least squares regression analysis (n = 30 for cluster 1, n = 18 for cluster 2 and n = 28 for cluster 3). The vinegar code corresponds with Table 1. The number of compounds corresponds with Table 2.  
**Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods11152224/s1](https://www.mdpi.com/article/10.3390/foods11152224/s1)]([https://www.mdpi.com/article/10.3390/foods11152224/s1](https://www.mdpi.com/article/10.3390/foods11152224/s1)), Figure S1: GC-MS total ion chromatograms of Ten-year aged Qian-he cellar vinegar (a), Ning-hua-mansion old vinegar (b), East-lake health vinegar (c), Qian-he glutinous rice vinegar (d), Heng-shun Jinyou balsamic vinegar (e), and potato vinegar (f); Figure S2: Geographical distribution of respondents; Table S1: Coefficient of PLSR models for each cluster of consumers. **Author Contributions:** [PERSON], [PERSON] and [PERSON] designed and managed the project. [PERSON]. ([PERSON]), [PERSON] and [PERSON]. ([PERSON]) performed all tests and analyzed the data. [PERSON], [PERSON] ([PERSON]) and [PERSON] wrote the manuscript. [PERSON], [PERSON] ([PERSON]), [PERSON] and [PERSON] revised the paper. 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.