# Characterization of Volatile Substances in Pu-erh Tea (Raw Tea) at Different Storage Times
## 3 Results and Analysis
### Sensory Evaluation of Pu-erh Tea During Storage
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample** & **Appearance** & **Soup Color** & **Aroma** & **Taste** & **Leaf Base** & **Score a** \\ \hline P1 & Round, buds with pekoe, brownish-blackish-brown & yellower, bright & Strong fruity/floral aroma & Rich, mellow, and thick & Soft, yellowish brown & 90 \\ \hline P2 & Round, buds with pekoe, brownish-blackish-brown & yellower, bright & Moderately rich & & Soft, yellowish & 87 \\ \hline P3 & Round, buds with pekoe, brownish-blackish-brown & yellow, bright & Fruity/floral aroma & & Soft, yellowish & 88 \\ \hline P4 & Round, buds with pekoe, brownish-blackish-brown & yellower, bright & Moderately rich & & Soft, brownish & 86 \\ \hline P5 & Round, buds with pekoe, brownish-blackish-brown & orange-yellow, bright & Strong fragrance aroma with a smoky aroma & & Soft, brownish & 88 \\ \hline P6 & Round, buds with pekoe, brownish-blackish-brown & orange-yellow, bright & Strong fragrance aroma with a smoky aroma & & Soft, brownish & 87 \\ \hline P7 & Round, buds with pekoe, brownish-blackish-brown & orange-yellow, bright & Fragrance aroma with a slight smoky aroma & Rich, mellow, and thick & Soft, brownish & 88 \\ \hline P8 & Round, buds with pekoe, brownish-blackish-brown & orange-yellow, bright & Moderately richer aroma, with a slight smoky aroma & & Soft, brownish & 86 \\ \hline P9 & Round, buds with pekoe, brownish-blackish-brown & orange-yellow, bright & Moderately richer smoky aroma & & Soft, brownish & 85 \\ \hline P10 & Round, buds with pekoe, brownish-blackish-brown & yellowish-orange, bright & Smoky aroma, high & & Soft, brownish & 85 \\ \hline P11 & Round, buds with pekoe, brownish-blackish-brown & orange-red, bright & Fragrance aroma, pure & & Soft, brownish & 85 \\ \hline P12 & Round, buds with pekoe, brownish-blackish-brown & light orange-red, bright & Fragrance aroma, high & & Soft, brownish & 86 \\ \hline P13 & Round, buds with pekoe, brownish-blackish-brown & yellow, bright & Moderately rich & & Soft, brownish & 84 \\ \hline P14 & Round, buds with pekoe, brownish-blackish-brown & Orange-red, moderately bright & Strong fragrance aroma and & & & Soft, & \\ \hline \hline \end{tabular}  
* Total Score = Appearance \(\times\) 20% + Soup color \(\times\) 10% + Aroma \(\times\) 30% + Taste \(\times\) 35% + Leaf base \(\times\) 5%.  
\end{table} 
Table 2: Sensory evaluation results of Liushan Pu-erh tea (raw tea). Among the volatiles, the highest proportion of the 14 Pu-erh tea (raw tea) samples was alcohols, which accounted for 20.76-34.04% of the total aroma component, followed by olefins and aldehydes, which accounted for 12.98-30.13% and 15.78-22.76% of the total aroma components, respectively. During the storage process, the contents of heterocyclic  
Figure 2: Heat map of 290 volatile components. compounds and aldehydes increased and then decreased, with a sharp increase to 7.14% and 16.25% in the 13 th year of storage. In contrast, the levels of olefins increased and then decreased in the opposite direction, with the highest content of 28.03% observed in the 16 th year of storage. Overall, the alcohols exhibited a trend of decreasing and then increasing, with the lowest content of 20.76% in the 17 th year of storage. Ketones and aromatic hydrocarbons showed an overall decreasing trend. The contents of ester, phenol, ether, acid, and alkane were lower, among which the ester and phenol showed a gentle increase in the storage process. The levels of ethers showed an overall increased trend, and the contents of ethers increased sharply in the 20 th year of storage, with a maximum of 11.57%, and the contents of alkanes and acids showed a decreasing trend overall.