## 5 Conclusions  
The final heating temperature in the evaporation process during NCS production, which operates between 120 and 140 \({}^{\circ}\)C, clearly altered its physical characteristics and volatile MRPs. Moisture content and water activity were reduced by half in the NCS from 140 \({}^{\circ}\)C heating compared to those in the NCS obtained from 120 \({}^{\circ}\)C evaporation. Increased evaporation temperature also produced NCS with a less bright and yellow color, as well as a greater ICUMA value (darker color), which greatly contributed to its appearance and color. The final heating temperature was also responsible for variations in the generation of volatile MRPs, including pyranone, furan, and pyrazine compounds. Higher evaporation temperatures increased the amounts of most of the MRPs isolated by PE membrane extraction, except for 2-acetylpyrrole. Moreover, the RAS system confirmed the presence of four MRPs: 2-furanmethanol, 2-methylpyrazine, 2,5-dimethylpyrazine, and 2,6-dimethylpyrazine. The concentrations of these compounds showed an increase with higher evaporation temperatures. There were strong negative correlations between physicochemical traits such as moisture content, water activity, brightness, yellow color, and MRPs from PE and RAS extractions. Conversely, significant positive correlations were confirmed between ICUMA values and the most volatile MRPs. Regarding volatile MRPs' isolation, the current study has focused on PE and RAS extraction techniques, wherein the isolated odorants may differ from those that human olfactory receptors can perceive. Nevertheless, these volatile extraction techniques effectively displayed the increments of volatile MRPs over evaporation temperature changes. Notably, the RAS presented for the first time an in vitro retronasal aroma model for NCS. Therefore, confirmation of the relationship between retronasal olfaction and sensory profiles could be an attractive topic for future research on NCS flavor quality. Taken together, the study shows that the evaporation temperature plays a crucial role in altering the key physicochemical and flavor characteristics of NCS. This outcome highlights the importance of adjusting the evaporation temperature during NCS production to improve storage stability and sensory characteristics, and thus quality.  
Conceptualization, Y.A., G.M. and K.W.; methodology, Y.A., H.K., K.T. and K.W.; software, G.M.; validation, Y.A., G.M. and K.W.; formal analysis, Y.N.; investigation, Y.A. and Y.N.; resources, G.M., K.T. and K.W.; data curation, Y.N.; writing--original draft preparation, Y.A. and Y.N.; writing--review and editing, Y.A. and K.W.; visualization, Y.A. and Y.N.; supervision, H.K., K.T. and K.W.; project administration, Y.A. and K.W.; funding acquisition, Y.A., G.M. and K.W. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the Japan Society for the Promotion of Science Grant Number 19K15784, an Academic Research Grant from the Urakami Foundation for Food and Food Culture Promotion, and a Special Promotion Research Grant from Okinawa Prefecture, Japan.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** We thank [PERSON] (University of the Ryukyus) for technical assistance with GC-MS analysis.  
**Conflicts of Interest:** The authors declare no conflict of interest.