## 2 Results
### Effect of Low-Sodium Salts on the Aroma of Dry-Cured Meat
#### 2.2.1 Volatile Compound Profile
The order of their content was SM > SPM > SP > SPMA and SM > SP > SPM > S > SPMA, respectively. SM was significantly higher than SPMA, because SM had a higher NaCl concentration and thereby promoted the formation of 3-Methylbutanal [30]. It is worth noting that Octyl aldehyde, Hexanal, Pentanal, and 1-Nonanal (linear aldehyde) respectively represent rancid smell, nutty aroma, grassy smell, and strong grease smell. The content of these compounds was relatively high, and the OAV values were all greater than 1, indicating that fat oxidation was active during the dry-curing process of the meat. The content order of each group of these compounds was SP > SM > SPM > SPMA > S, among which SP was significantly higher than S. These compounds usually originate from fat autooxidation reactions [31; 32], and adding low-sodium salt will increase the content of the aforementioned linear aldehydes because low-sodium salt promotes fat oxidation. It was speculated that the pro-oxidative activity of lower concentrations of NaCl may be further enhanced due to the presence of K\({}^{+}\)[11]. (_E_)-2-Heptanal and (_E_)-2-Nonenal had a green, fatty, and rancid taste, but there were no significant differences between the groups. Decyl aldehyde has a spicy waxy odor and is formed by \(\beta\)-oxidation of unsaturated fatty acids [33]. The Decyl aldehyde content in SP was significantly higher than that in SPMA and S, which may be explained by the fact that the presence of KCl enhances the \(\beta\)-oxidation reaction [33]. (_E_)-2-Octenal exhibited a sweet aroma or the smell of cucumber or melon. The (_E_)-2-Octenal in SP and SPM was significantly higher than that in SPMA, SM, and S, because SM contains more diketone compounds and amino acids (Table 3 and Table S1), while the formation of (_E_)-2-Octenal requires free amino acids and diketone compounds. Alcohols often have aromatic, vegetal, and earthy notes and are an integral part of dry-cured cuts of meat. A total of 8 alcohols were detected in the meat, and the order of the total content of each group was as follows: SM > SP > SPM > SPMA > S, among which SM, SP, and SPM were significantly greater than SPMA and S, indicating that the low-sodium group without Arg addition significantly increased the alcohol content of dry-cured meat, because NaCl itself has antibacterial activity, whereas partial substitution will result in stronger microbial growth and higher branched-chain alcohol production [34]. Among the eight alcohols, the OAVs of 3-Methyl-1-butanol, 1-Pentanol, 1-Hexanol, 1-Octen-3-ol, 1-Heptanol, and 1-Octanol were all greater than 1. No significant difference was observed in each group for alcohols containing 3-Methyl-1-butanol, 1-Pentanol, 1-Hexanol, and 1-Octen-3-ol. 1-Heptanol has a strong aromatic odor, and the order of content in each group was SM > SP > SPM > S > SPMA, with SM being significantly higher than the other groups. 1-Octanol has a pungent odor, which may come from the oxidation of myristic acid, linoleic acid, palmitoleic acid, or oleic acid. The order of the content of each group was SP > SM > SPM > SPMA, among which SP was significantly higher than SPMA. There was no Octanol in S, probably because the high content of NaCl inhibited the growth of microorganisms and reduced the production of branched-chain alcohols. Ester compounds are derived from the esterification reaction of carboxylic acids and alcohols. Esters containing short-chain acids have a fruity flavor, but long-chain acids produce fatty flavors [28]. The order of the total content of esters in each group was SM > SPMA > S > SPM > SP. SM was significantly higher than SP, indicating that partial replacement of magnesium increases the content of esters in dry-cured meat.