## 3 Results and Discussion
### Comparison of Bioactive Components
#### 3.3.1 Fatty Acids
The findings were consistent with the results of this study, as shown in Table 2, as the compositions of SFAs, MUFAs, and PUFAs at the sn-2 position among C.O, C.S, C.G, and C-C.O showed a range of 1.66-5.61%, 81.15-86.85%, and 11.43-15.23%, respectively, which were higher than those in the sn-1,3 position (15.16-20.10%, 72.63-76.03%, and 7.29-9.21%, respectively). When considering DAG-enriched camellia oils, commercial _C. oleifera_-DAG (40% and 80%), it had been reported that 1,2-(or 2,3)-diacyl-sn-glycerol (1,2-DAG) and 1,3-diacyl-sn-glycerol (1,3-DAG) typically maintain a dynamic equilibrium through acyl migration during enzymatic processes and in the presence of acid, alkali, or heat, with a ratio of 1,2-DAG to 1,3-DAG of approximately 7:3 [49]. Therefore, differences in the distribution of fatty acids on the glycerol backbone were expected in DAG-enriched camellia oils (Table 2). The distribution characteristics of fatty acids in different varieties of camellia oils and DAG-enriched camellia oils were analyzed using cluster heat map and principal component analysis (PCA) with the distributions of fatty acids on different glycerol backbones as variables, as shown in Figure 3. The results revealed distinct groupings among the six types of oils based on their total fatty acid composition. Firstly, C.O and C.G form one group, characterized by relatively high levels of palmitic acid (C16:0), \(\alpha\)-linolenic acid (C18:3 n-3), and margaric acid (C17:0). Secondly, C-C.O and its DAG-enriched counterparts (C-C.O-DAG 40% and 80%) form another group with relatively high levels of palmitoleic acid (C16:1) and linoleic acid (C18:2 n-6). Lastly, represented by C.S, it exhibited higher levels of n-9 fatty acids (C18:1 n-9, C20:1 n-9, and C22:1 n-9) and SFAs (C14:0, C18:0, and C20:0) (Figure 3a). Accordingly, the results of PCA using total SFAs, MUFAs, and PUFAs as variables showed that C.O, C.S, and C.G were characterized by high levels of SFA among different types of camella oils. In contrast, total MUFAs and PUFAs were representative of C-C.O and its DAG-enriched counterparts, especially C-C.O-DAG 40% and 80% (Figure 3b), suggesting that the relative content and saturation of fatty acids in camella oil can be used as indicators to distinguish different types of camella oil [20; 45]. For instance, [PERSON] et al. [20] demonstrated that the content of oleic acid (C18:1 n-9) in C. _deifera_ (77.12-79.50%) and C. _chekiangoleosa_ (75.97-79.33%) was significantly higher compared to C. _sinensis_ (49.07-56.27%) (\(p<0.05\)). Conversely, the content of palmitic acid (C16:0) in C. _deifera_ (8.37-8.92%) and C. _chekiangoleosa_ (7.45-9.06%) was notably lower than in C. _sinensis_ (13.52-17.55%). Furthermore, when considering the distribution of specific fatty acids at the sn-1,3 position, C-C.O and its DAG-enriched counterparts (C-C.O-DAG 40% and 80%) could be clearly differentiated based on their fatty acid profiles. For instance, C-C.O and C-C.O-DAG (40%) were distinguished by their high levels of palmitoleic acid (C16:1) and \(\alpha\)-linolenic acid (C18:3 n-3), respectively, while C-C.O-DAG (80%) exhibited notably high levels of linoleic acid (C18:2 n-6) and oleic acid (C18:1 n-9) (Figure 3c), similar to total fatty acids. In addition, PCA of the total SFAs, UFAs, and PUAs at the sn-1,3 positions clearly showed that the DAG-enriched counterparts (C-C.O-DAG 40% and 80%) had a significant composition of unsaturated fatty acids, including MUFAs and PUFAs (Figure 3d). In contrast, the three varieties of camella oils exhibited distinct fatty acid profiles at the sn-2 position. As depicted in Figure 3e,f, C.S showed a preference for oleic acid (C18:1 n-9), C.O was characterized by higher levels of C14:0, and C.G contained elevated levels of C20:0 and linoleic acid (C18:2 n-6). Moreover, C-C.O and its DAG-enriched counterparts (40% and 80%) could be clearly differentiated based on the presence of oleic acid (C18:1 n-9), linoleic acid (C18:2 n-6), and palmitic acid (C16:0) at the sn-2 position, respectively (Figure 3e).