# Characteristic Aroma Compound in Cinnamon Bark Extract Using Soybean Oil and/or Water
## 3 Results and Discussion
### Changes in the Overall Flavor Profile  
PLS-DA was carried out to evaluate the relationships between the OAVs of aromatic compounds and the water extract samples (Figure 1a), and the first two principal components explained 88% of the total variation (68.1% and 19.9%, respectively). Figure 1b shows the relationships between the contribution rate of OAVs of aroma-active compounds and the water extract samples, and the first two principal components explained 94% of the total variation (65.7% and 28.7%, respectively). The score plots (colored spots) in Figure 1a,b suggested that the water extract of different stewing times was separated from one another. Cinnamaldehyde and 1-octen-3-ol, which present \"cinnamon\" and \"mushroom\" odors, respectively, had a close correlation with the 30-min extraction group, and their relative concentrations in the 30-min extraction group were higher than those in the other groups. Therefore, the water extract of cinnamon for 30 min was a better alternative for conserving extraction time and improving aroma intensity.  
Biplot of PLS-DA for the OAVs of aroma-active compounds with the oil/water extract samples was performed (Figure 2a), and the first two principal components explained 93% of the total variation (69.6% and 24.7%, respectively). The correlations between the contribution rate of OAVs of aroma-active chemicals and the oil/water extract samples are shown in Figure 2b, and the first two principal components explained 94% of the total variation (69.6% and 26.4%, respectively). The score plots (colored spots) in Figure 2a,b suggested that the 30- and 60-min extract groups were distinguished from the 90-min  
Figure 1: Biplot of partial least-squares discriminant analysis for water extract samples with OAVs (**a**) of contribution rates of OAVs (**b**) of aroma-active compounds. Spots in color (W\(-\)i\(-\)j): sample numbers, where w is the water extract, i is the number of stewing times, and j is the number of test replicates.  
extract group in the PC1 dimension and that the 30- and 60-min extract groups were distinctly separated in the PC2 dimension.  
Cinnamaldehyde and eucalypt, which show \"cinnamon\" and \"minty, eucalyptus\" odors [22; 23], respectively, had a high correlation with the 30-min extraction group, and eucalypt might enhance the aroma of the cinnamon extract. Furthermore, the relative concentrations of these two compounds in the aqueous phase of the 30-min extraction group were higher than the relative concentrations in the other groups. As a result, 30 min of stewing is a reasonable duration for oil/water extraction of cinnamon bark.  
According to the information acquired, whether it is oil/water extraction or water extraction, 30 min of extraction was advised based on economic cost, efficiency, and aroma intensity. However, it was also found that the relative concentrations of aroma-active compounds in the aqueous phase of the oil/water extraction were significantly lower than those in the water extraction. Furthermore, stewing meat with oil, water, and spices was more common and representative [6]. The oil layer in the oil/water extraction had the potential to bind volatile compounds and shield the phase migration of odorants with high vapor pressure [40], according to the previous analysis results. As a result, the aroma secrets of traditional Chinese meat products made by stewing meat with oil, water, and spices should be dependent on the oil layer, which was also the next step we would carry out.