## 2 Results and Discussion
### Fingerprinting of Cinnamon NMR Dataset
#### 2.4.4 Unsupervised Analyses of Cinnamon Dataset by NMR  
Authenticated (except for CT) and commercial cinnamon products were modeled. The analysis was based on the full \({}^{1}\)H-NMR scale (\(\delta_{\text{H}}\) 1-10 ppm), providing an overview of the primary metabolites that usually appear in the aliphatic shielded region and secondary bioactive metabolites appearing in the aromatic deshielded region (\(\delta_{\text{H}}\) > 5.5 ppm).  
Analysis of the Whole Samples' NMR Dataset  
Based on the full \(\delta_{\text{H}}\) scale, HCA (Figure 5A) showed a clear clustering of CA replicates from the other cinnamon samples. Furthermore, CI and CV were likely to be similar enough to be grouped together. However, commercial products proved to be different from the authenticated samples and clustered in a separate group. Albeit, CP-3 replicates were found to be different from the other commercial products. These findings were confirmed by heatmap analysis (Supplementary Figure S5) which might be explained by the different constituents of CP-3 (Table 1). Asides, the PCA score plot showed a relatively strong model, where PC1 explained 79% of the total variance (82%) and could show segregated samples along with it. CA and CP-3 were the most unique samples confirming the HCA results, which clustered to the right-side and top-side of the model, respectively. In addition, CP-2 and CP-4 were clustered in one group proving their comparable composition, Figure 5B. Such findings were in agreement with SPME/GC-MS results, although they could not reveal the origin of commercial products. Moreover, the loading plot (Figure 5C) showed that all chemical shift markers colored red belonged to primary metabolites (\(\delta_{\text{H}}\) < 5.0 ppm), including fatty acids and ascorbic acid at 1.32 ppm and 3.67 and 4.79 ppm, respectively. Interestingly, N1 and N15 were found to be associated with and could be recognized as markers for CA and CP-3, respectively. There was only one aromatic chemical shift at 8.28 ppm, which is related to niacin (N14) and to be a potential marker for CP-3.  
The aromatic region (\(\delta_{\text{H}}\) 5.5-10.0 ppm) is usually modeled to better identify markers from the flavor and secondary bioactive metabolites. The PCA score plot (Figure 5D) resulted in the discrimination between investigated samples in the same manner previously observed for the full scale (Figure 5B) with better discrimination parameters, i.e., PC1 = 86.1%. Asides, the PCA loading plot (Figure 5E) revealed that (\(E\))-methoxy cinnamaldehyde (N10) appeared to be rich in CV and in agreement with GC/MS results being located with negative PC2 values. Furthermore, niacin (N14) was more associated with CP-3 causing its segregation on the far-left upper quadrant negative PC1 and positive PC2. However, we cannot readily predict from NMR results the origin of commercial preparations whether they belong to either CA or CV, in contrast to GC/MS findings, Figure 3.  
Analysis of Commercial Samples' NMR Dataset  
The commercial cinnamon samples were modeled separately to show their inter-relationship based on NMR analysis. The PCA score and loading plots are shown in Supplementary Figure S6A,B, respectively. The score plot showed that also CP-3 was unique and segregated away from the other three commercial samples to the positive side of PC1, accounting for 88.3%. Moreover, the loading plot demonstrated that CP-1 and CP-4 were higher in (\(E\))-cinnamaldehyde than CP-3, and in accordance with GC/MS results, Figure 3C.