## 2 Results
### Principal Component Analysis (PCA) of Physicochemical Properties, Aroma, Taste, and Sensory Scores  
PCA can reduce the dimensionality of complex data and further reflect the overall information provided by the sample. In Figure 7, PC1 and PC2 cover 41.8% and 19.5%, respectively, with a cumulative value of 61.3%. The five treatment groups in this study were clearly separated in terms of PC1. Furthermore, SP differed from other components by PC2 through indicators such as sweet amino acids, aldehydes, pyrazines, shear force, and K\({}^{+}\) content. Most physicochemical properties were grouped in the negative quadrant of PC1, whereas most sensory attributes, electronic nose odor, and free amino acid content were grouped in the positive quadrant of PC1. The components detected by GC-MS, especially aldehydes, ketones, alcohols, and pyrazine, have a strong correlation with the odor detected by electronic nose. S was described as related to shear force, aromatic compound content, Na\({}^{+}\) content, and \(b^{*}\). However, excessive shear force and pH are detrimental to meat products. SM was described as related to electronic tongue aftertaste, free amino acids, total amino acids, and electronic tongue bitterness. SM and S were the farthest apart, indicating a significant difference between them, which was conducive to the enhancement of the quality of dried-cured meat in terms of shear force, water loss, and pH. In addition, SPMA was considered to be related to \(A_{\text{w}}\), ester content, TBARS, Mg\({}^{2+}\) content, sensory properties, and bitter amino acids. Also, SP was described as related to electronic nose S9, sensory hardness, sweet amino acid content, aldehyde content, and K\({}^{+}\) content.  
Importantly, SPMA, SPM, and SM containing Mg\({}^{2+}\) had more volatile compounds than SP in terms of flavor (Figure 3). Sensory evaluation also found that SM had a higher overall acceptance compared to other groups. Therefore, magnesium ions contribute to improving the quality of dry-cured meat products.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **S** & **SPMA** & **SPM** & **SP** & **SM** \\ \cline{2-6}  & & & **Score** & & \\ \hline Redness & 2.53 \(\pm\) 0.99 A & 3.08 \(\pm\) 1.14 A & 2.67 \(\pm\) 1.23 A & 3.17 \(\pm\) 1.10 A & 3.15 \(\pm\) 1.32 A \\ Homogeneity & 3.11 \(\pm\) 0.96 A & 3.33 \(\pm\) 1.08 A & 3.17 \(\pm\) 1.10 A & 3.00 \(\pm\) 1.14 A & 3.22 \(\pm\) 1.22 A \\ Gloss & 2.73 \(\pm\) 0.91 A & 3.18 \(\pm\) 0.87 A & 3.03 \(\pm\) 1.12 A & 2.61 \(\pm\) 0.78 A & 3.25 \(\pm\) 0.97 A \\ Saltiness & 3.83 \(\pm\) 1.14 A & 3.99 \(\pm\) 0.76 A & 3.44 \(\pm\) 0.78 A & 3.88 \(\pm\) 0.95 A & 4.02 \(\pm\) 0.84 A \\ Bitterness & 1.42 \(\pm\) 0.77 A & 1.69 \(\pm\) 0.89 A & 1.86 \(\pm\) 1.16 A & 1.81 \(\pm\) 0.93 A & 1.53 \(\pm\) 0.81 A \\ Umami & 2.12 \(\pm\) 1.09 A & 2.56 \(\pm\) 0.99 A & 2.39 \(\pm\) 1.05 A & 2.33 \(\pm\) 1.08 A & 2.62 \(\pm\) 1.10 A \\ Sweetness & 1.36 \(\pm\) 0.72 A & 1.31 \(\pm\) 0.62 A & 1.36 \(\pm\) 0.64 A & 1.36 \(\pm\) 0.64 A & 1.42 \(\pm\) 0.65 A \\ Hardness & 2.93 \(\pm\) 0.93 A & 3.00 \(\pm\) 0.69 A & 2.96 \(\pm\) 1.12 A & 3.32 \(\pm\) 1.01 A & 2.99 \(\pm\) 0.83 A \\ Fat adhesion & 2.33 \(\pm\) 1.03 A & 2.44 \(\pm\) 1.10 A & 2.22 \(\pm\) 0.94 A & 2.28 \(\pm\) 1.02 A & 2.72 \(\pm\) 1.07 A \\ Chewiness & 3.03 \(\pm\) 0.96 A & 3.47 \(\pm\) 0.88 A & 3.08 \(\pm\) 1.03 A & 3.12 \(\pm\) 0.77 A & 3.36 \(\pm\) 1.11 A \\ Acceptance & 3.31 \(\pm\) 1.05 A & 3.08 \(\pm\) 1.29 A & 3.04 \(\pm\) 1.24 A & 3.06 \(\pm\) 0.87 A & 3.08 \(\pm\) 1.09 A \\ \hline \hline \multicolumn{6}{l}{S: 100\% NaCl: SPMA: 59.375\% NaCl+28\% KCl+12\% MgCl\({}_{2}\)+0.625\% L-arginine (Arg): SPM: 60\% NaCl+28\% KCl+12\% MgCl\({}_{2}\); SP: 72\% NaCl+28\% KCl; SM: 88\% NaCl+12\% MgCl\({}_{2}\). Different letters in the same group indicate significant differences (\(p<0.05\); Tukey test).} \\ \end{tabular}
\end{table}
Table 4: Sensory evaluation scores of dry-cured meat with different low-sodium salt formulations.