## 3 Results
### pH, Water Activity, TBARS
The correctness of using PCA analysis was analyzed using the KMO index and [PERSON]'s test of sphericity, which results were shown in Table 4. The KMO index (higher than 0.5) as well as results of [PERSON]'s test confirmed the correctness of application PCA analysis in this case. The results of PCA shown in Table 5 revealed that the first two principal components explained 88.94% of the cumulative variance, with 76.34% of total variance explained by the first principal component (PC1). The plane of the first two principal components is shown in the Figure 1. The highly positive loading of pH and water activity count in PC1 indicated the high dependence of these two variables during the experiment. A similar arrangement of variables with high negative loading (Figure 1) in PC1 has shown a significant effect between parameters related to proteolysis (TN, NPN, PI) as well as total pigments and heme iron content. Second principal component explained 12.60% of cumulative variance and is correlated highly only with TBARS. The content and antioxidant activity of peptides isolated from dry fermented sausages at the end of manufacturing (21 day) is shown in Table 6. The sausage samples were characterized by the mean peptide content from 9.69 \(\pm\) 1.19 to 11.70 \(\pm\) 0.49 mg g\({}^{-1}\) of product. The peptide content of salted sample (S) and sample with liquid acid whey and sodium ascorbate (SAWA) was significantly lower compared to the cured sample with sodium nitrite (C). However, the antioxidant activity of peptides was independent of their content because the sample SAWA with the lowest peptide content showed the highest antioxidant activity, which was significantly higher compared to the C and S sausage samples. The antioxidant activity of peptide isolated from dry fermented sausage with acid whey addition (SAW) did not differ significantly from the SAWA sample. \begin{table}
\begin{tabular}{c c} \hline \hline
**Test** & **Result** \\ \hline KMO index & 0.75 \\ \hline [PERSON]’s test of sphericity & \\ \hline Approximate \(\chi^{2}\) & 791.92 \\ \hline Degrees of freedom & 28 \\ \hline Significance & \textless{}0.000001 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Results of KMO and Bartlett’s tests calculated for parameters investigated during processing of sausages. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Variable** & **PC1 (76.34\%)** & **PC2 (12.60\%)** \\ \hline pH & 0.954 & 0.067 \\ aw & 0.976 & 0.042 \\ proteolysis index (PI) & \(-\)0.870 & \(-\)0.036 \\ Total nitrogen (TN) & \(-\)0.910 & \(-\)0.074 \\ Non protein nitrogen (NPN) & \(-\)0.974 & \(-\)0.064 \\ Total pigments (TP) & \(-\)0.922 & 0.090 \\ Heme iron (HI) & \(-\)0.922 & 0.090 \\ TBARS & 0.107 & \(-\)0.988 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Correlation of variables to factors in principal component analysis based on factor loadings. Table 7 reports the amount of the identified amines at the end of the manufacturing of dry-fermented sausages. Four biogenic amines were identified in the experimental sausages (tyramine, putrescine, cadaverine and spermine). Histamine, spermidine and agmantine were not detected. The detection limits of the method were 100 pmol for histamine and agmantine and 50 pmol for spermidine. The most abundant biogenic amine present in all sausages were the tyramine. The lowest tyramine content was found in the sausage sample with the addition of acid whey and sodium ascorbate, followed by the sample SAW with acid whey, then salted sample S. The highest concentration of this BA, twice as high as compared to the SAWA sample, was achieved for cured sample C with the addition of sodium nitrite. All sausage samples showed similar amounts of spermine, ranging from 32.65 \(\pm\) 2.07 to 40.70 \(\pm\) 10.47 mg kg\({}^{-1}\).