# Influence of LAB Fermentation on the Color Stability and Oxidative Changes in Dry-Cured Meat
## 4 Discussion  
Since LAB are considered natural antioxidants, several mechanisms are involved in their antioxidant effect, such as redox regulation, production of antioxidant metabolites, free radical scavenging, and metal ion chelation. For example, the cell-free LAB cell extract showed good Fe\({}^{2+}\) and Cu\({}^{+}\) chelating abilities. Therefore, LAB cells may contain related metal-chelating agents that determine their high antioxidant activity [29, 30, 31]. In addition, several studies have shown that the intracellular antioxidant activity of LAB is based on the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), nicotinamide adenine dinucleotide oxidase (NADH), NADH peroxidase, and GSH [31, 32, 33]. To illustrate this, the antioxidant activity of lactic acid bacteria P. pentosaceus, Lactobacillus curvatus, Lactobacillus brevis, and Lactobacillus fermentation isolated from dry Harbin sausage was evaluated. The in vitro results demonstrated that P. pentosaceus showed the highest resistance to H\({}_{2}\)O\({}_{2}\), radical scavenging activity, reducing power, and inhibition of lipid peroxidation. Moreover, the SOD and GPx activities in P. pentosaceus were higher than in the other strains, and these results correlated with the lower rates of fat and protein oxidation in Harbin sausage [34]. Thus, antioxidant enzymes play an indispensable role in the high antioxidant activity of LAB. Therefore, LAB inoculation during the production of fermented meat products may influence the oxidation of meat during its long-term aging and storage. However, the presence of LAB in meat products also affects their physical and chemical parameters (including pH), which is attributable to the specific characteristics of the ripening products. Based on the acidification of the meat tissue by LAB, pH values of, on average, 5.447 and 5.353 were observed in this study for the control sample and LAB variants, respectively. The lower pH value for the samples inoculated with the starter culture was due to the activity of micro-organisms capable of producing lactic acid, thus acidifying the meat matrix, as described by [PERSON] et al. [35], [PERSON] et al. [36], [PERSON] and [PERSON] [37], and [PERSON] et al. [38]. The effect of LAB on the water activity of meat products was also \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & **TBARS** & **ORP** & \(\mathbf{O_{\text{N}}_{\text{i}}}\) & **HS** & **SH** \\ \hline \multirow{4}{*}{C} & TBARS & & & & & 0.690 \\  & ORP & & & & \(-\)0.787 & \\  & OS\({}_{\text{i}}\) & & & \(-\)0.787 & & \\  & HS & & & \(-\)0.690 & & \\ \hline \multirow{4}{*}{LOCK} & TBARS & ORP & \(\mathbf{O_{\text{N}}_{\text{i}}}\) & HS & SH \\  & TBARS & & & & 0.823 & \\  & ORP & & & & \(-\)0.920 & \\  & Ox\({}_{\text{i}}\) & & & & & \\  & HS & & & \(-\)0.920 & & \\  & SH & & & & & \\ \hline \multirow{4}{*}{BB12} & TBARS & ORP & \(\mathbf{O_{\text{N}}_{\text{i}}}\) & HS & SH \\  & TBARS & & & & & \\  & ORP & & & & \(-\)0.777 & \\  & Ox\({}_{\text{i}}\) & & & & & \\  & HS & & & & & \\  & SH & & & \(-\)0.777 & & \\ \hline \multirow{4}{*}{BAUER} & TBARS & & & \(-\)0.823 & & \\  & ORP & & & & & \\ \cline{1-1}  & Ox\({}_{\text{i}}\) & \(-\)0.823 & & & 0.739 & 0.739 \\ \cline{1-1}  & HS & & & 0.739 & & 1.000 \\ \cline{1-1}  & SH & & & 0.739 & & 1.000 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Linear correlation coefficient for oxidation parameters (only statistically significant correlation (\(p<\) 0.05) is presented). observed, where a higher value of water activity was recorded (an average value of 0.825) compared with that of the control samples (an average value of 0.811) during the storage of the test samples from 6 to 12 months. Water availability is correlated with water activity and is an important factor for the development of micro-organisms, including LAB, on dried meat products. However, \(\mathrm{a_{w}}\) can be a criterion for the microbiological safety of cured meat products.