## 3 Results  
The results regarding the presence of _Salmonella_ in scaling water over the course of the experiment are shown in Figure 2.  
Once _Salmonella_ occurred, it remained in the scaling water until the end of the experiment. This is generally the case under normal conditions. Directly after applying the treatments by increasing the temperature of the scaling water, the results showed an absence of _Salmonella_ in all cases (t\({}_{i}\) + 8 h). However, when the treatment used a temperature of 60 \({}^{\circ}\)C, two hours later, _Salmonella_ reappeared on five of the six days of the experiment (83.3%). After treatment at 70 \({}^{\circ}\)C, _Salmonella_ remained absent for longer, even until the end of the day in 33.3% of the cases. The influence of the treatment showed statistical differences (\(p<0.05\)) in terms of the impact of the decrease in the occurrence of _Salmonella_. The effects of decreasing the pH of scaling water on the occurrence of _Salmonella_ and microbial indicators are shown in Table 1 and Figures 3 and 4. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline  & **t\({}_{i}\)** & **t\({}_{i}\) + 2 h** & **t\({}_{i}\) + 4 h** & **t\({}_{i}\) + 6 h** & **t\({}_{i}\) + 8 h** & **t\({}_{i}\) + 10 h** & **t\({}_{i}\) + 12 h** & **t\({}_{i}\) + 14 h** & **t\({}_{i}\) + 16 h** \\ \hline pH & 5.5 & 5.65 & 5.75 & 5.86 & 6.05 & 6.15 & 6.35 & 6.38 & 6.45 \\ _Salmonella_ & - & - & - & + & + & + & + & + & + \\ \hline pH & 5.0 & 5.06 & 5.23 & 5.42 & 5.55 & 5.61 & 5.87 & 5.96 & 6.16 \\ _Salmonella_ & - & + & - & + & + & + & + & + & + \\ \hline pH & 4.5 & 4.65 & 4.78 & 4.96 & 5.02 & 5.25 & 5.39 & 5.56 & 5.75 \\ _Salmonella_ & - & - & - & - & + & + & + & - & + \\ \hline pH & 4.0 & 4.12 & 4.37 & 4.51 & 4.75 & 4.86 & 4.91 & 5.05 & 5.26 \\ _Salmonella_ & - & - & - & - & - & + & + & + & + \\ \hline pH & 3.5 & 3.58 & 3.76 & 3.89 & 4.15 & 4.27 & 4.36 & 4.46 & 4.65 \\ \hline \end{tabular}
\end{table} 
Table 1: Evolution of _Salmonella_ determination after applying acidification (with different initial pH values) to scaling tank water. Figure 3: Evolution of _E. coli_ occurrence in scalp water during scaling step from different pH initial. Figure 2: Occurrence of _Salmonella_ in scaling tank water throughout 2 h intervals during a slaughter day. As expected, the pH increased throughout the scaling process due to the accumulation of organic matter. The microbial indicators showed consistency with the expected results (Figures 3 and 4). The evolution of _E. coli_ showed a clear difference between cases where the initial pH was either above or below 4.5. With initial pH values of 3.0, 3.5, and 4.0, _E. coli_ evolution remained at a minimum slope (\(p<0.05\)). Also, in the case of mesophilic aerobic bacteria (MAB), the gradient of the curves between the initial pH series was evident. The occurrence/absence of _Salmonella_, which was the main parameter, confirmed the effectiveness of this measure. In this respect, the occurrence/absence of _Salmonella_ is clearly influenced by acidification. When the initial pH was 5.5, _Salmonella_ occurred after 6 h. When the initial pH was 5.0, _Salmonella_ was regularly detected after 6 h. When the initial pH was 4.5, it was detected after 8 h. If the initial pH was 4.0, _Salmonella_ was detected after 10 h. When the initial pH was 3.5, occurrence was observed after 14 h, and when the initial pH was 3.0, the result was the absence of _Salmonella_ throughout the process. The results of the acidification of the scaling water show a statistically significant influence (\(p<0.05\)). Sensory tests showed that all of the parameters which were studied remained \"Normal\", with no defaults reported, as shown in Table 2.