## 5 Conclusions  
The TA values and the TSS/TA ratio are convenient traits for differentiating shiikuwasha and calamansi; we found that the TA value was significantly higher in calamansi, while the TSS/TA ratio was lower. Positive correlations were found between total carotenoid content and red, yellow, and orange indices; the total carotenoid contents were highest in calamansi. Shiikuwasha juice was rich in sucrose and choline, while fructose, glucose, and organic acids were more abundant in the calamansi juice, indicating that differentiation is possible according to taste-related metabolites such as sugars and organic acids. VOCs were more abundant in the whole juice than in the flesh juice from shiikuwasha and calamansi. The composition of the VOCs in the juices may indicate different aroma qualities. The PCA of the combined taste-related metabolite and VOC data elicited a clear separation of the three shiikuwasha cultivation lines from calamansi according to the intensity of the flavor-contributing substances when unpeeled fruits were processed into foods and beverages. Taken together, the results of the present study reveal the physicochemical traits and flavor components of Okinawan shiikuwasha and calamansi fruits. The findings also provide valuable information for producers and consumers when making choices for processing and purchasing the two citrus cultivars.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14156746/s1](https://www.mdpi.com/article/10.3390/app14156746/s1)]([https://www.mdpi.com/article/10.3390/app14156746/s1](https://www.mdpi.com/article/10.3390/app14156746/s1)), Figure S1: Representative \({}^{1}\)H-NMR spectra of metabolite components in shiikuwasha and calamansi; Figure S2: Representative GC-MS chromatograms of the VOCs in shiikuwasha and calamansi; Figure S3: PCA plots of VOCs in shiikuwasha and calamansi juices; Table S1: Composition of volatile organic compounds in shiikuwasha and calamansi juices.  
Conceptualization, Y.A., F.M., K.T. and K.W.; methodology, Y.A, Y.S., K.T. and K.W.; software, M.O., Y.A., Y.S. and K.T.; validation, M.O., Y.A, Y.S., K.T. and K.W.; formal analysis, M.O. and Y.A.; investigation, M.O., Y.A., F.M. and. Y.S.; resources, Y.A., F.M. and K.W.; data curation, M.O. and Y.A.; writing--original draft preparation, M.O. and Y.A.; writing--review and editing, M.O., Y.A. and K.W.; visualization, M.O.; supervision, Y.A., K.T. and K.W.; project administration, Y.A., K.T. and K.W.; funding acquisition, Y.A. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Lotte Research Promotion Grant from the Lotte Foundation of Japan.  
Not applicable.  
The original contributions presented in the study are included in the article/Supplementary Material, further inquiries can be directed to the corresponding author.  
**Acknowledgments:** The work is part of the dissertation submitted by the first authors in partial fulfillment of a Ph.D. degree. We thank [PERSON] and [PERSON] (University of the Ryukyus) for their technical assistance with the analysis of the physicochemical traits and data preparation. The metabolite analysis was performed at the Center for Research Advancement and Collaboration, University of the Ryukyus.  
**Conflicts of Interest:** The authors declare no conflicts of interest.