# Influence of LAB Fermentation on the Color Stability and Oxidative Changes in Dry-Cured Meat
## 4 Discussion
In general, the highest growth of micro-organisms is observed between \(\mathrm{a_{w}}\) values of 0.980 and 0.995, and the growth is inhibited at approximately 0.85 [39], which is in agreement with the present study. These findings are consistent with those of other studies using the same LAB strains. Color stability during processing and storage is an important distinguishing feature of meat products. It influences the sensory attractiveness of these products and is the major factor encouraging the purchase by the customer. Discoloration of fermented meat products is caused by a variety of factors, such as dehydration, acidification, and oxidation. The critical factors affecting the color of the meat product are as follows: the content and chemical state of myoglobin (oxidation of myoglobin causes the accumulation of metmyoglobin and meat discoloration), reductase activity, and muscle structure (degradation and oxidation of meat proteins may relax muscle fibers and affect the scattering of light by the muscle while assessing the color, thus giving the impression of lightness in the meat). Changes in meat color coordinates (\(L^{*}\), \(a^{*}\), and \(b^{*}\)) over time are closely related to changes in myoglobin due to oxidation. The increased metmyoglobin content is responsible for the browning of meat (associated with the loss of color stability), thus resulting in the loss of redness (\(a^{*}\)) and changes in yellowness (\(b^{*}\)). [PERSON] [40] reported that the iron-porphyrin coordination complex of the denatured globin molecule is responsible for the brownish gray color that occurs due to cold cuts. Modification of this structure leads to the degradation and the subsequent release of the heme molecule, which is one of the pro-oxidative factors. As a result of the chemical composition of the raw material used in this study, i.e., a high protein content with a lower fat content, the oxidative changes primarily affected proteins. Therefore, proteins may be responsible for the loss of color of meat products [41]. In the present study, the influence of LAB on color parameters, including brightness, was demonstrated, where samples subjected to spontaneous fermentation (C) were generally darker (\(p<0.05\)) than other research variants. Otherwise, the brightness remained the same throughout the entire testing period, except for the BAUER test where a decrease in brightness was observed. While evaluating the color stability caused by oxidation, the redness and yellowing parameters are more significant than brightness. Reduction in meat redness, which is correlated with the presence of an oxidized form of myoglobin and a brown shade of meat, was observed in the control and LOCK samples, whereas BB and BAUER samples showed a higher redness (except for the last study period, when a decrease in \(a^{*}\) was observed). Moreover, BB and BAUER tests were characterized by a higher value of yellowness (\(b^{*}\)), which indicates the higher influence of myoglobin oxidation on the color stability in these tests. As reported by [PERSON] et al. [42], myoglobin oxidation is correlated with lipid oxidation, and one may exacerbate the other. In addition, oxidation of myoglobin (Fe\({}^{2+}\)) to metmyoglobin (Fe\({}^{3+}\)) produces pro-oxidants that may intensify further oxidation of lipids or other proteins in food [42]. The TBARS are the most commonly used indicators of the degree of oxidation in food products and are directly related to the fat content. In the present study, after 6 months of aging, a TBARS value of 2.446 mg/MDA was observed in the control sample, which is consistent with the reports of [PERSON] et al. [35] in dry-cured necks (2.26 mg/MDA), although the same authors simultaneously reported a lower TBARS value in B. animals ssp. lactis BB12 tests (1.52 mg MDA/kg ([PERSON] et al. [35] as much as 1.666 mg MDA/kg [38]) than that achieved in the present study (2.476 mg MDA/kg) after 6 months.