# Improving the Sensory Quality of Black Tea by Blending Varieties During Processing
## 3 Results and Discussion
### Analysis of Volatile Components by GC-MS
#### 3.3.2 Key Aroma-Active Volatiles in Different Blending Treatments  
According to our analysis of eight key aroma-active volatiles found in Fud, FJG, and FJX, we observed a significant increase (_p_ < 0.05) in volatiles with floral characteristics in FJG or FJX samples (Figure 3D, Table 2). The volatile phenylacetaldehyde has a honey-like and sweet odor, contributing to the honey-like aroma profiles in tea samples [42]. In the present  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multirow{2}{*}{**OT (mg/kg)**} & \multirow{2}{*}{**Odor Descriptor**} & \multicolumn{3}{c}{**ROAV**} & \multirow{2}{*}{_p_} \\ \cline{3-3} \cline{5-6}  & & & **Fud** & **FJG** & **FJX** \\ \hline
2-methylbutanal & & cocoa, almond (*) & 43.28 & 31.76 & 34.24 & \textless{}0.05 \\ D-limonene & 0.004 & mint, lemon, citrus, orange, fresh, sweet (*, \#) & 46.25 & 37.75 & 80.25 & \textless{}0.05 \\  & & lemon, citrus, orange, floral, & & & & \\  & 0.028 & sweet, woody, blueberry, laverander, flower, green (*, \#) & 35.99 & 54.07 & 50.05 & \textless{}0.05 \\ phenylacetaldehyde & 0.002 & cocoa, grapefruit, green, peanut, floral, bitter (*, \#) & 162.50 & 131.50 & 213.00 & \textless{}0.05 \\  & 0.19 & flower (*) & 0.93 & 5.19 & 3.95 & \textless{}0.05 \\ benzyl alcohol & 0.62 & walnut, sweet, cherry, phenolic, flower, grapefruit (*, \#) & & & & \\  & 0.0056 & oil, ethereal, resin, fused, sweet, & 0.00 & 0.00 & 15.00 & \textless{}0.05 \\  & 0.0058 & fruity (\#) & 0.57 & 4.14 & 0.86 & \textless{}0.05 \\  & 0.0059 & fruity, wood (*) & - & - & - & \textless{}0.05 \\  & 0.  
work, phenylacetaldehyde exhibited the highest ROAV and was significantly increased in FJX (Figure 3D, Table 2), which means phenylacetaldehyde played an important role in the formation of the honey-like aroma in FJX. Phenylacetaldehyde was found at a higher concentration in JX compared to Fud and JGY, indicating that it is a volatile characteristic of the Jinxuan variety. Additionally, the content of D-limonene was also significantly increased in FJX (\(p<0.05\)), and presented the same change trend as phenylacetaldehyde (Figure 3D, Table 2). D-limonene has been reported as a key compound with a higher ROAV in the renowned Darjeeling black tea [43]. It can be considered that FJX contains a higher level of D-limonene, which is beneficial for improving aroma quality. 2-Pentylfuran exhibits a fruity aroma and is only present in FJG, indicating it might be an important contributor to the fruity aroma in FJG. The volatile 1-hexanol was only determined in FJX, linked to a sweet, fruity, and floral-like aroma. Investigation has shown that 1-hexanol significantly decreases during the fermentation process of black tea [44]; its presence in FJX may connect with complex enzymatic reactions. In addition, 1-hexanol is easily vaporized during the drying process in black tea and oolong tea due to its lower boiling point [45], making it difficult to retain in tea leaves after exposure to high temperatures during drying. Benzyl alcohol andlinal oxide (pyranoid) are two floral-like aroma compounds in black tea, and their concentration was significantly increased (\(p<0.05\)) in FJG and FJX. This may be an important reason for the prominent floral aroma in FJG and FJX. Benzyl alcohol can be formed through the hydrolysis of benzyl \(\beta\)-D-glucose compounds [46], and is also derived from phenylpyruvate acid in tea leaves via enzyme reaction [47], meaning a high level of enzyme activity promotes the accumulation of benzyl alcohol. Investigation has identified benzyl alcohol as a key volatile in various teas with a sweet-floral profile [48; 49]. [PERSON] et al. [50] confirmed thatlinal andlinal oxide were dominant volatile components in Keemun black tea, with their content increasing alongside the grades of black tea [51]. It has been reported thatlinal oxides originate from the glycoside forms of linalool in fresh tea leaves, rather than from the oxidization of linalool itself [37].