# Effect of Fermentation Technology and Storage Time on the Quality of Salami-Type Sausages
## 3 Results and Discussion
### Influence of Fermentation Technology on the Microbiological Characteristics of Salami-Type Sausages
The formation of this curing pigment involves a complex interplay of microbiological, enzymatic, and chemical processes influenced by variables such as pH, receptors, redox potential, and curing agent distribution. Temperature is employed not only to inhibit the growth of undesirable microorganisms such as _Clostridium botulinum_ but also for its effectiveness as an antioxidant, hindering lipid oxidation and the development of rancid off-flavors [60; 61]. The decision to introduce nitrites to fermented sausages hinges on the attainment of the characteristic red color, which is extensively detailed in the literature, including the influence of reducing agents (e.g., ascorbate/ascorbic acid) on expediting the conversion of nitrite to NO [62]. The color parameter values in the cross-sections of the salami-type sausages are detailed in Table 5. It was noted that immediately after ripening (on day 0), \"warm\"-fermented and \"cold\"-fermented sausages exhibited comparable (\(p>0.05\)) levels of L* and a* color parameters, averaging 51.2-53.8 and 16.9-18.7 units, respectively. Furthermore, irrespective of the fermentation technology, no notable disparities in sausage brightness (L*) and redness (a*) were detected during cold storage (Table 5). The formation of nitrosylmyoglobin (after curing) and a decrease in the pH level of a cured meat product (due to lactic acid production) can contribute to the development and stability of its color. Nevertheless, color deterioration can be caused by other reactions, including the oxidation of fats and proteins [63; 64]. On day 0 of cold storage, the fermentation method did not exert the b* color parameter (indicating yellowness) of the salami-type sausages. However, after 21 days of storage, the yellowness of the WF was significantly (\(p\leq 0.05\)) greater compared to the CF sausages. Furthermore, the duration of cold storage did not demonstrate a significant impact (\(p>0.05\)) on the variation in the yellowness of the sausages produced using either fermentation method (Table 5). The differences in yellowness between the WF and CF sausages' cross-sections could have resulted from more intense oxidative changes of fats in the sausages obtained using \"warm\" fermentation (see details in Table 3). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Fementation Technology**} & \multicolumn{4}{c}{**Storage Time [Days]**} \\ \cline{2-5}  & **0** & **21** & **42** & **63** \\ \hline \multicolumn{5}{c}{L* [-]} \\ \hline Warm & 52.21 \(\pm\) 0.90 nA & 53.43 \(\pm\) 1.19 nA & 53.64 \(\pm\) 0.83 nA & 53.77 \(\pm\) 0.87 nA \\ Cold & 51.27 \(\pm\) 0.89 nA & 51.89 \(\pm\) 0.40 nA & 51.81 \(\pm\) 0.39 nA & 51.34 \(\pm\) 1.25 nA \\ \hline \multicolumn{5}{c}{a* [-]} \\ \hline Warm & 18.72 \(\pm\) 1.14 nA & 17.33 \(\pm\) 2.68 nA & 18.23 \(\pm\) 0.36 nA & 18.64 \(\pm\) 0.87 nA \\ Cold & 16.87 \(\pm\) 0.22 nA & 17.24 \(\pm\) 0.59 nA & 17.52 \(\pm\) 0.38 nA & 17.29 \(\pm\) 0.66 nA \\ \hline \multicolumn{5}{c}{b* [-]} \\ \hline Warm & 5.95 \(\pm\) 0.60 nA & 6.37 \(\pm\) 0.20 aB & 6.42 \(\pm\) 0.10 aB & 6.51 \(\pm\) 0.24 aB \\ Cold & 5.33 \(\pm\) 0.38 nA & 5.43 \(\pm\) 0.25 nA & 5.45 \(\pm\) 0.15 nA & 5.28 \(\pm\) 0.21 aB \\ \hline \multicolumn{5}{c}{\(\Delta\)E\({}_{0}\) [-]} \\ \hline Warm & - & 1.90 \(\pm\) 0.74 nA & 1.58 \(\pm\) 0.69 nA & 1.66 \(\pm\) 0.30 aA \\ Cold & - & 0.73 \(\pm\) 0.77 nA & 0.85 \(\pm\) 0.57 aA & 0.65 \(\pm\) 0.87 aA \\ \hline \hline \end{tabular} L*–lightness, a*–redness, b*–yellowness, \(\Delta\)E\({}_{0}\)—total color difference compared to day 0. Different lowercase letters between mean values \(\pm\) standard deviations in the row indicate significant differences (grouping variable: storage time), \(p\leq 0.05\). Different uppercase letters between mean values \(\pm\) standard deviations in the column for a given parameter indicate significant differences (grouping variable: fermentation technology), \(p\leq 0.05\).  
\end{table}