## 3 Results
### VOCs Profile  
The evolution of the volatileome composition for each product was visualized with an HCA heatmap based on a log\({}_{2}\)(n) ratio of the mean concentrations amended by the median value (Figures 5-7). The SG volatilome composition showed the lowest complexity, with 59 compounds detected using SPME-GC/MS. Twenty-eight were identified as terpen, which were probably related to the presence of the spices (black pepper, dill) used in the curing step, where their concentrations remained stable during the storage period. As the storage progressed, an increase in the concentrations of alcohols (ethanol, 3-methyl-1-butanol, 2,3-butanediol, 1-octen-3-ol, phenylethyl alcohol), aldehydes (nonanal, (E,E)-2,4-decadien), aromatic aldehydes (benzaldehyde, benzeneacetaldehyde), ketones (2-butanone, 1-octen-3-one) and 1-pentadecene was visible (Figure 5). Conversely, the alkane concentrations of, e.g., undecane, dodecane, tridecane and tetradecane, decreased over time. The MAP and VP CSS volatilome compositions were much more complex than in the gravlax, with 164 and 149 compounds detected, respectively. For both products, more than half of all compounds were identified as furan and aromatic compounds that were related to the smoking process. In the case of the VP CSS, despite the heterogeneity between the samples, a trend emerged that was characterized by an increase in the concentration of some aldehydes (decanal, hexadecanal), aromatic aldehydes (benzaldehyde, benzeneacetaldehyde), phenylethyl alcohol and 3,4-dimethyl-2-hydroxycyclopent-2-en-1-one (Figure 6). An increase in the production of dimethylamine (at days 28 and 35) and ethanol (at days 35 and \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Sampling** & **0** & **7** & **14** & **21** & **28** & **35** & **42** & **49** \\
**Date (days)** & & & & & & & & \\ \hline
**SG** & & & & & & & & \\  pH & 5.87 \(\pm\) 0.10 & 5.93 \(\pm\) 0.02 & 5.62 \(\pm\) 0.04 & 5.81 \(\pm\) 0.03 & 5.77 \(\pm\) 0.02 & 5.84 \(\pm\) 0.02 & - & - \\  TVBN & 12.0 \(\pm\) 1.8 & 15.1 \(\pm\) 0.9 & 22.2 \(\pm\) 5.3 & 24.9 \(\pm\) 4.9 & 28.2 \(\pm\) 1.0 & 23.1 \(\pm\) 1.3 & - & - \\  Cadaverine & 2.0 \(\pm\) 0.1 & 6.0 \(\pm\) 3.6 & 294.2 \(\pm\) 224.1 & 275.8 \(\pm\) 30.6 & 404.1 \(\pm\) 79.4 & 73.5 \(\pm\) 58.2 & - & - \\  Tyramine & 2.0 \(\pm\) 0.1 & 2.0 \(\pm\) 0.1 & 65.3 \(\pm\) 60.9 & 42.2 \(\pm\) 12.9 & 63.5 \(\pm\) 15.3 & 13.0 \(\pm\) 12.0 & - & - \\  Histamine & 0.7 \(\pm\) 0.6 & 1.3 \(\pm\) 0.6 & 116.8 \(\pm\) 104.3 & 57.7 \(\pm\) 7.7 & 77.3 \(\pm\) 24.0 & 17.1 \(\pm\) 12.7 & - & - \\ **MAP CSS** & & & & & & & & \\  pH & 5.68 \(\pm\) 0.02 & 5.81 \(\pm\) 0.01 & 5.53 \(\pm\) 0.07 & 5.70 \(\pm\) 0.02 & 5.65 \(\pm\) 0.04 & 5.63 \(\pm\) 0.02 & - & - \\  TVBN & 14.4 \(\pm\) 0.7 & 14.6 \(\pm\) 1.0 & 14.2 \(\pm\) 1.9 & 14.8 \(\pm\) 1.0 & 13.3 \(\pm\) 2.6 & 16.8 \(\pm\) 2.1 & - & - \\  Cadaverine & 2.3 \(\pm\) 2.1 & 4.7 \(\pm\) 0.6 & 9.0 \(\pm\) 5.6 & 6.7 \(\pm\) 2.0 & 6.2 \(\pm\) 1.0 & 4.4 \(\pm\) 0.4 & - & - \\  Tyramine & 0.0 & 0.0 & 3.3 \(\pm\) 3.1 & 0.2 \(\pm\) 0.4 & 0.3 \(\pm\) 0.5 & 6.2 \(\pm\) 2.7 & - & - \\  Histamine & 3.7 \(\pm\) 3.2 & 6.0 \(\pm\) 1.0 & 8.0 \(\pm\) 2.0 & 5.3 \(\pm\) 0.6 & 5.5 \(\pm\) 1.5 & 5.2 \(\pm\) 0.7 & - & - \\ **VP CSS** & & & & & & & & \\  pH & 5.63 \(\pm\) 0.03 & 5.81 \(\pm\) 0.02 & 5.47 \(\pm\) 0.04 & - & 5.64 \(\pm\) 0.07 & 5.76 \(\pm\) 0.01 & 5.60 \(\pm\) 0.05 & 5.57 \(\pm\) 0.013 \\  TVBN & 14.5 \(\pm\) 1.6 & 17.1 \(\pm\) 1.3 & 17.5 \(\pm\) 1.3 & - & 21.0 \(\pm\) 3.7 & 24.7 \(\pm\) 2.5 & 24.6 \(\pm\) 3.6 & 25.9 \(\pm\) 5.0 \\  Cadaverine & 4.0 \(\pm\) 1.0 & 4.0 \(\pm\) 0.1 & 4.6 \(\pm\) 0.9 & - & 153.4 \(\pm\) 160.5 & 185.0 \(\pm\) 186.3 & 185.3 \(\pm\) 281.7 & 218.9 \(\pm\) 187.9 \\  Tyramine & 0.0 & 0.0 & 0.0 & - & 26.7 \(\pm\) 36.0 & 37.8 \(\pm\) 43.9 & 49.5 \(\pm\) 78.5 & 38.8 \(\pm\) 33.7 \\  Histamine & 6.7 \(\pm\) 1.2 & 5.7 \(\pm\) 0.6 & 5.6 \(\pm\) 0.2 & - & 33.4 \(\pm\) 29.6 & 56.3 \(\pm\) 61.9 & 10.8 \(\pm\) 6.0 & 59.4 \(\pm\) 45.2 \\ \hline \end{tabular} \(\cdot\) not determined.  
\end{table}