## 3 Results and Discussion
The measured a* values in the single-treated sous-vide meat samples were stable at both temperatures during the storage period. In contrast, the pressure-treated meat samples recovered part of their redness during the 21-day storage both at 2 \({}^{\circ}\)C and at 8 \({}^{\circ}\)C. This phenomenon was observed at both pressure levels, but it was more intense in the 300 Mpa-treated samples. Lipid oxidation measurements diversify our samples well. In the case of day 0 HHP-treated samples, the higher pressure level resulted in higher TBARS values (1.67 and 2.98 mg MDA/kg), while HHP 300 and SV samples were in the same range (1.67 and 1.84 mg MDA/kg). Regarding the effect of storage, the 300 Mpa samples were stable but at a higher (8 \({}^{\circ}\)C) temperature, the TBARS value was slightly higher, though not significant. SV and HHP samples showed a further increase of secondary oxidation products during the 3-week storage period, meaning significantly higher TBARS values. Nota bene, pressure treatment at a higher level induced more important degradation of the lipids than the sous-vide heat treatment did. These findings are in accordance with the results of [PERSON] et al. [22] concerning pork. They found no significant effect under a 200 Mpa treatment, but the next pressure level applied (400 Mpa) already showed increased TBARS values, which rose further as the pressure level was set to 600 Mpa. Regarding heat treatment, [PERSON] et al. [54] proposed to keep sous-vide temperature and heat treatment time at a minimal level to maintain product quality. This advice prioritized both oxidative stability and organoleptic quality. Meat toughness is another elemental sensory parameter. The sous-vide cooking method gained popularity mainly because of its tenderizing effect. [PERSON] et al. [55; 56] found that the low-temperature-long-time heat treatment increases tenderness in comparison to traditional cooking. In our experiment, the sous-vide heat treatment was sufficient to result in a tender sample, and this texture characteristic was nearly constant during the storage period (Table 3). The 600 MPa pressure-treated samples had similar hardness values to the sous-vide samples. It can be related to the 'doneness' of the samples, as the 600 MPa pressure-treated samples were very similar in appearance to the cooked ones. Their appearance and behavior were similar to that of the cooked samples. DSC enthalpy values can confirm this (meaning the undenatured ratio of meat proteins), as compared to the sous-vide samples, the 600 MPa pressure-treated samples showed nearly 50% lower measured enthalpy values. Incontrast the 300 MPa samples showed similar total enthalpy values as the sous-vide samples although similar values were obtained it is due to the denaturation of different protein groups (Figure 1a). The sous-vide cooking alone dramatically reduced the microbial population at the applied time-temperature combination. Both aerobic and anaerobic viable counts increased during storage time at 8 \({}^{\circ}\)C, but not at 2 \({}^{\circ}\)C. The importance of the storage temperature of the sous-vide products is emphasized [1, 44], as our study proves again the necessity of strict storage parameters. The microbial state of the samples treated with HHP at 300 Mpa was clearly not satisfactory after the storage period. It also left uncertainties concerning the day 0 samples regarding their aerob TVC  
they reached log10\({}^{8}\) TVC (at 8 \({}^{\circ}\)C) in all single-treated samples. [PERSON] et al. reported similar results [57] for sous-vide-treated pork loin for both weight loss, texture, and color measurement results, but it should be emphasized that their research focused more on kinetic analysis and the effect of treatment temperature (in the 60-75 \({}^{\circ}\)C range).