# Physicochemical and Microbiological Changes Associated with Processing in Dry-Cured Tuna
## 4 Conclusions  
The present study evaluated different quality parameters during the different steps of the manufacturing process of dry-cured tuna (_mojama_). A significant decrease in \(\mathrm{a_{w}}\) and moisture with respective final values of 0.86 and 33.3% were associated with the salting \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Raw Tuna** & **Salting** & **Salt-Washing** & **Dry-Cured Tuna** & _p-Value_ \\ \hline mesophilic flora (cfu/g) & average & 3.0 \(\times\) 10\({}^{2}\) & 3.1 \(\times\) 10\({}^{3}\) & 2.2 \(\times\) 10\({}^{3}\) & 4.9 \(\times\) 10\({}^{2}\) & *** \\  & min-max & 3.6 \(\times\) 10\({}^{2}\)\(-\)4.8 \(\times\) 10\({}^{3}\) & 2.5 \(\times\) 10\({}^{2}\)\(-\)6.5 \(\times\) 10\({}^{3}\) & 8 \(\times\) 10\({}^{2}\)\(-\)4 \(\times\) 10\({}^{3}\) & 3 \(\times\) 10\({}^{-1}\).2 \(\times\) 10\({}^{3}\) & \\  & average & 1.8 \(\times\) 10\({}^{2}\) & n.d. & 0.003 & 0.06 & ns \\  & min-max & n.d.\(-\)1.7 \(\times\) 10\({}^{3}\) & n.d. & n.d.\(-\)2 \(\times\) 10 & n.d.\(-\)3 \(\times\) 10\({}^{2}\) & \\  & average & 1.2 \(\times\) 10\({}^{3}\) & 3.8 \(\times\) 10\({}^{2}\) & 4.2 \(\times\) 10\({}^{2}\) & 1.1 \(\times\) 10\({}^{3}\) & ** \\  & min-max & 4 \(\times\) 10\({}^{2}\)\(-\)6 \(\times\) 10\({}^{3}\) & n.d.\(-\)2.4 \(\times\) 10\({}^{3}\) & n.d.\(-\)9.6 \(\times\) 10\({}^{2}\) & 10\({}^{2}\)\(-\)2.8 \(\times\) 10\({}^{3}\) & \\ \hline _Enterobacteriaceae_ & & n.d. & n.d. & n.d. & n.d. & \\ _Staphylococcus aureus_ & & n.d. & n.d. & n.d. & n.d. \\ _Listeria monocytogenes_ & & n.d. & n.d. & n.d. & n.d. \\ _Salmonella_ & & n.d. & n.d. & n.d. & \\ \hline \hline \end{tabular}
\begin{tabular}{c c} \hline \hline \multicolumn{1}{c}{Different letters in the same row indicate significant differences by [PERSON]’s test. ***, ns—significant at \(p<0.01\), \(p<0.001\) and not significant, respectively. n.d.—not detected.} \\ \end{tabular}
\end{table} 
Table 4: Microbiological count in the different steps of the manufacturing process of _mojama_. and drying steps. The bright red color of the raw tuna joins gradually became darker and duller, eventually turning into the characteristic brownish color of _mojama_. The increase of TVBN observed after the drying step could be due to the concentration effect caused by the water loss and may be due to the degradation of proteins as a result of lipid and protein oxidation. Final products with an \(\mathrm{a_{w}}\) below 0.9 do not pose a risk by pathogen bacteria to consumer health since they cannot grow in those conditions. Based on the results obtained, we can conclude that the salting step during the manufacturing process of _mojama_ improves its stability in the initial stage of the process, inhibiting undesirable reactions and promoting the flavor of the product. Finally, the drying step enhances the preservation effect of the salt and is necessary for achieving a lower \(\mathrm{a_{w}}\) and further increasing the stability of the final dry-cured tuna. The control of time is important to prevent the proliferation of spoilage bacteria before the salting step. Thus, the raw tuna must be handled by specialized operators for short periods of time, and they must observe strict hygiene protocols. As the production of _mojama_ is of great importance to the economy of the regions in which it is produced, and its fame is attributed to its high quality, it is of crucial importance for the producer companies to keep optimizing their elaboration techniques and follow good manufacturing practices to ensure safety and quality in their product. Conceptualization, J.L.O.-D., J.P.-A. and J.M.M.-R.; methodology, M.S.-P., J.L.O.-D., J.P.-A.