## 3 Results and Discussion
According to the existence and/or composition of the variables, the tendency of meat to lipid peroxidation is affected by the species of animal, kind of muscle, and anatomical site [51]. Lipid oxidation is a spontaneous and unavoidable process taking place during postmortem aging [52] and does not stop during long-term freezer storage. The results of malondialdehydedehyde determination in samples while being stored in vacuum packages are shown in Table 6. On the first day of this experiment, the lowest MDA values in pig meat were measured in the LM samples. On the 180 th day of storage, an increased content of MDA in PM samples was observed followed by a decrease until the 360 th day of the experiment. In WB meat samples, a decrease in MDA content was detected up to the 270 th day and a repeated increase on the 360 th day of storage. In FD meat during storage, a gradual decrease of MDA was noted during the first 270 days of the experiment. In the SM meat samples of PM and WB, there was a lower MDA content than in FD. The MDA values rose up to the 90 th day of storage in the vacuum-packed samples. On the 360 th day the lowest values were measured in FD of PM samples. \begin{table}
\begin{tabular}{c c c c c} \hline
**Meat Sample** & **Storage (Days)** & **Fallow Deer** & **Wild Boar** & **Pig** & \(p\)**-Value** \\ \hline \multirow{2}{*}{Loin meat} & 0 & 0.115 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.054 \(\pm\) 0.01 \({}^{\text{b}}\) & 0.025 \(\pm\) 0.00 \({}^{\text{c}}\) & \textless{}0.001 \\  & 90 & 0.098 \(\pm\) 0.02 \({}^{\text{a}}\) & 0.054 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.034 \(\pm\) 0.01 \({}^{\text{b}}\) & \textless{}0.001 \\  & 180 & 0.086 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.055 \(\pm\) 0.01 \({}^{\text{b}}\) & 0.063 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.009 \\  & 270 & 0.082 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.044 \(\pm\) 0.01 \({}^{\text{b}}\) & 0.055 \(\pm\) 0.01 \({}^{\text{b}}\) & 0.004 \\  & 360 & 0.084 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.063 \(\pm\) 0.01 \({}^{\text{ab}}\) & 0.041 \(\pm\) 0.01 \({}^{\text{b}}\) & 0.008 \\ \hline \multirow{2}{*}{Shoulder meat} & 0 & 0.060 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.038 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.034 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.003 \\  & 90 & 0.139 \(\pm\) 0.01 \({}^{\text{a}}\) & 0.045 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.055 \(\pm\) 0.00 \({}^{\text{b}}\) & \textless{}0.001 \\  & 180 & 0.065 \(\pm\) 0.02 & 0.062 \(\pm\) 0.00 & 0.058 \(\pm\) 0.01 & 0.781 \\  & 270 & 0.076 \(\pm\) 0.02 \({}^{\text{a}}\) & 0.050 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.053 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.024 \\  & 360 & 0.048 \(\pm\) 0.00 \({}^{\text{b}}\) & 0.075 \(\pm\) 0.02 \({}^{\text{a}}\) & 0.044 \(\pm\) 0.01 \({}^{\text{bThe lowest MDA content was recorded on the initial day of the trial in the TM samples of WB. During storage, the increase of MDA was up to the 180 th day of storage. Subsequently, MDA content in meat samples decreased until the end stage of the trial. At the end of the trial, comparable MDA values were measured in all TM samples. The increase in MDA values determined during storage and TBA in pig meat samples stored over 180 days are comparable to [PERSON] et al. [53]. The rise of MDA values is a sign that the meat lipids have been oxidized [54]. The rise in MDA content up to the 180 th day of storage can be explained by the gradual transformation of primary oxidation products (hydroperoxides) into secondary oxidation products (hydrocarbons, alcohols, aldehydes, and fatty acids) where MDA is the main secondary product that is produced in the largest amount during the oxidative degradation of lipids. The decrease in MDA can be explained by the effect of vacuum packaging when access to air is prevented and further oxidation processes do not occur. Substances reacting with TBA as well as MDA reached threshold levels, then started to break down and interact with other substances resulting in lower values when kept for a long time [55]. Meat samples were vacuum-packed before being frozen which, according to [PERSON] et al.