# Aroma Characteristics of Lavender Extract and Essential Oil from _Lavandula angustifolia_ Mill.
## 2 Results and Discussion
### Odor Property of Lavender Extracts
#### 2.1.1 Effect of Extraction Solvent on the Volatile Compositions of LEs  
A total of thirty-three volatile compounds were identified by GC-MS. In detail, a number of 32, 32 and 33 volatile compounds were found in LE-W (extraction with purified water), LE-A99 (extraction with 99% edible ethanol) and LE-A95 (extraction with 95% edible ethanol), respectively, and the total amounts of volatiles in each sample were 83.60%, 90.42% and 96.40%, respectively. These identified volatiles belonged to various chemical groups, including alkenes, alcohols, ketones, esters and aldehydes. The number and proportion of these chemical categories varied in the three samples (Figure 1A) and the majority were esters, alcohols and alkenes with fruity, floral or spicy notes.  
The ester compounds dominated the volatile compositions in the three samples, and eight volatile compounds were identified in each sample, accounting for 60.91%, 62.91% and 64.85% of the total amount of volatiles in LE-W, LE-A99 and LE-A95, respectively. As displayed in Table 1, linaly4 acetate and lavandulyl acetate with floral odors reminiscent of lavender [1] were of high abundance and their total amounts were more than 57% of the total amount of volatiles in the three samples, and the highest amount was 58.50% in LE-A95 and the lowest amount was 57.32% in LE-W. The number of alkene compounds was the highest, and ten chemical compounds were identified in each sample, but the relative content was significantly different among the three samples, being the highest at 11.99% in LE-A95 and the lowest at 8.45% in LE-A99. (_E_)-\(\beta\)-Caryophyllene and (_E_)-\(\beta\)-farnesene, which were of spicy and floral odors, respectively [17; 18], were the two abundant alkenes with a relative content higher than 1%. The LE-W contained the lowest number and amount of alcohol compounds (6 and 10.49%, respectively). No significant difference was observed on the amount of alcohols between LE-A95 and LE-A99 (15.66% and 15.20%, respectively). 1-Octen-3-ol with earth odor [19] was only identified in LE-A95. Linalool was the most abundant alcohol in the three samplesand was considered as the key aroma-active compound imparting a floral note for lavender [20; 21]. Volatiles in LE-A95 possessed the strongest intensity of floral odor, most reasonably due to the highest amount of linalool (12.51%), and were significantly higher than that in other samples. Besides linalool, the highest amounts of linalool oxides (I and II) with floral odors were found in LE-A95. Four ketone compounds were identified in each sample, and the lowest amount of ketones was found in LE-A95, while the highest amount of ketones was found in LE-W (0.83% and 1.29%, respectively). The amount of camphor imparting camphoreous, minty and herbal odors [22; 23] was lower than 0.30% in the three samples and met the needs of international standards with the amount below 0.5% in lavender flavoring [24]. Only cumaldehyde with spicy odor [25] was identified in aldehydes and the amount was less than 1% in each sample.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**RT**} & \multirow{2}{*}{**RI**} & \multirow{2}{*}{**Volatile Compounds**} & \multicolumn{3}{c}{**Relative Content (\%)**} & \multirow{2}{*}{**ID \({}^{*}\)**} \\ \cline{5-6}  & & & & & **LE-A95** & & **LE-W** \\ \hline
1 & 2.44 & 666 & Acetic acid & 0.22 \(\pm\) 0.01 & 0.71 \(\pm\) 0.00 & 0.59 \(\pm\) 0.02 & MS, RI, S \\