# Profiling Croatian Whisky Using GC/MS-MS and UHPLC-QTOF
## 4 Conclusions  
This study successfully identified and analyzed both volatile and non-volatile compounds in Croatian whiskies using SPME-GC-MS and UHPLC-QTOF methods, respectively. Figure 4: Dendrogram of clustering based on the similarity matrix of analyzed whiskies. Red: Croatian single malt whisky, light green: Croatian four grain whisky, dark blue: blended Scotch whisky, pink: single malt Scotch whisky, light blue: blended Scotch whisky, dark green: single malt Scotch whisky, olive: blended Scotch whisky, purple: blended Scotch whisky, brown: methanol. Figure 3: Principal Component Analysis (PCA) plot of different whisky samples analyzed using UHPLC-QTOF. Whisky 1: Croatian single malt whisky; 2: Croatian four grain whisky; 3: blended Scotch whisky; 4: single malt Scotch whisky; 5: blended Scotch whisky; 6: single malt Scotch whisky; 7: blended Scotch whisky; 8: blended Scotch whisky; MEOH: methanol. Key aroma compounds identified include D-limonene, linalool, and \(\beta\)-damascenone, which contribute citrus, floral, and fruity notes, respectively. The aromatic profile of Croatian whiskies revealed a range of compounds that significantly influence their sensory characteristics. Furthermore, several compounds were associated with the longer aging of whisky: es-culetin, ellagic acid, lyoniresinol 9-glucosidase, lyoniresinol, and (E)-2-nonenal. These compounds contribute to the complexity and depth of the whisky's flavor, with esculetin and ellagic acid offering potent antioxidant properties, while lyoniresinol and its glucosides are linked to lignans found in grains and oak wood. The compounds identified from the single malt and four grain whiskies indicate a diverse and rich aromatic profile. Ethyl hexanoate and ethyl heptoate contribute fruity notes reminiscent of red apple and pineapple. D-limonene provides a sweet orange citrus aroma, while linalool adds floral and spicy notes reminiscent of lavender and bergamot. The presence of (E)-2-nonenal introduces fried, toasted, and fatty aromas, which are essential for the characteristic profiles of aged whiskies. These findings highlight the intricate interplay of various chemical compounds that define the unique flavor and aroma of Croatian whiskies. The maturation process, grain type, fermentation, and distillation methods all contribute significantly to these profiles, showcasing the complexity and craftsmanship involved in whisky production. Finally, the aromatic and non-volatile compounds identified in Croatian whiskies not only differentiate them from other whiskies but also underline the potential for further exploration in the field of whisky chemistry and flavor science. This study provides a foundation for future research aimed at understanding and enhancing the sensory qualities of whisky through detailed chemical analysis. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15052738/s1](https://www.mdpi.com/article/10.3390/app15052738/s1)]([https://www.mdpi.com/article/10.3390/app15052738/s1](https://www.mdpi.com/article/10.3390/app15052738/s1)), Figure S1. Unknown compound 1 with molecular mass 1006.12918 \(m/z\); Figure S2. Unknown compound 2 with molecular mass 978.09907 \(m/z\); Figure S3. Multivariate Analyses and Clustering of Croatian and Scotch Whiskies Based on Untarget QToF Analysis of Non-Volatile Compounds. Conceptualization, A.L. and H.B. ; methodology, A.C. and M.C. ; formal analysis, A.L. ; resources, T.A. and H.B. ; writing--original draft preparation, A.L. and A.-M.G.S. ; writing--review and editing, M.L. and B.M. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The data presented in this study are available upon request from the corresponding author. [PERSON] and [PERSON] are employee of the company Spirit in the bottle. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflicts of interest.