## 5 Conclusions  
This study showed that the process and packaging conditions both had an effect on the microbial composition and the quality of the final product. Although the sensory spoilage was generally weak, gravlax was the most perishable product, followed by the VP CSS and MAP CSS. This result is in accordance with all the parameters measured in this study. The TVBN, cadaverine, tyramine and histamine were in higher concentrations in the SG, followed by the VP CSS and then the MAP CSS. The microbial diversity in gravlax was high, probably due to the spices and herb additions in the process and the absence of antimicrobial phenolic compounds. LAB aside, the most abundant genera that were identified using metabarcoding (_Photobacterium_, _Serratia/Yersinia_ and _Brocht thrix_) are known to be specific spoilage microorganisms in seafood. In the smoked product, after 28 days, the VP selected _Photobacterium_ as the dominant flora but LAB, Enterobacteriaceae and _Brocht thrix_ were still present. The MAP selected only LAB (mainly _Lactobacillus_) as the dominant flora, which did not deteriorate the sensory quality.  
The following are available online at [[https://www.mdpi.com/article/10](https://www.mdpi.com/article/10)]([https://www.mdpi.com/article/10](https://www.mdpi.com/article/10)) 3390/foods10112517/s1. Table S1: OTU Table. Table S2: Volatile Organic Compounds Table.  
**Author Contributions:** Conceptualization, F.L., M.-F.P., N.W. and D.P.; methodology and microbial analysis, N.W. and F.G.; sensory analysis, M.C. and J.C.; metabarcoding, N.W. and S.S., Metabarcoding--  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Genus** & **Ecological Origin** & **References** \\ \hline
**Bacteria** & & \\ _Brachybacterium_ & & \\  & animal feces & \\ _Duganella_ & Soil, plant roots, water & [89; 90; 91] \\ _Terribacillus_ & Soil, salted lake sediment, plant material & [92; 93; 94] \\ _Spelaococcus_ & & Soil \\ _Brevbacterium_ & Soil, seawater, feces, compost, plant material, milk, & [96; 97; 98; 99; 100] \\ _Comamonas_ & Freshwater, plant, compost, soil, fish gut & [101; 102; 103; 104; 105] \\ _Sphingobacterium_ & Soil, permafrost, glacier, animal feces and gut, milk, & [106; 107; 108; 109; 110; 111; 112] \\
**Archaea** & & & \\ _Halorubrum_ & Salt-fermented seafood, rock salt, salted lake sediment, & [113; 114; 115; 116] \\ _Halohasta_ & Salted lake water, aquaculture water & [117] \\ \hline \hline \end{tabular}
\end{table}
Table 3: Ecological origin of uncommon genera that were only detected using the metabarcoding approach in salmon dill gravlax.  
data treatment, N.W.; volatiles organics compounds (VOCs), J.R.; VOCs--data treatment, J.R. and N.W.; ComDim, E.V. and P.C.; writing--original draft preparation, N.W. with contributions from [PERSON] and E.V.; writing--review and editing, F.L. and M.-F.P.; supervision, F.L. and M.-F.P.; project administration, F.L.; funding acquisition, F.L. and M.-F.P. All authors have read and agreed to the published version of the manuscript.  
This study was supported by a public grant from the French Agence Nationale de la Recherche within the context of the ERANET COFASP program (reference ANR-14-COFA-0001, project SAFEFISHIDISH).  
The authors thank [PERSON] and [PERSON] for their kind technical assistance with the biogenic amines, TVBN and TMA analyses and [PERSON] for their help regarding the DNA extraction.  
The authors declare no conflict of interest.