## 1 Introduction
Combining these two physical minimal processing methods--a thermal and a non-thermal technique--without altering the composition with the addition of acids or preservative chemicals seems to fulfill the requirements. Following the hurdle principle [25], the heat treatment may increase the lethality and decrease the intensity of the high-pressure treatment process [26]. In fact, the sous-vide technology itself is a three-step combined technology and thus a good example of the hurdle principle [25]. It combines (i) vacuum packaging with the exclusion of oxygen and resulting anaerobic conditions, (ii) mild heat treatment (55-90 \({}^{\circ}\)C) with precise temperature control, and (iii) quick cooling and refrigerated storage after heat treatment. The high hydrostatic pressure as an additional hurdle may reduce the necessity of strict refrigeration and could mean safer and more stable products, lower costs, higher nutritional value, and easier handling. As the PA/PE pouch packaging of the raw material is suitable for both technologies, cross- and post-contamination is excluded at all levels of the technology chain during treatments. Traditional cooking methods, pasteurization alone, or pressure treatment at ambient temperature are not sufficient to inactivate bacterial spores. Even when food is processed for extended holding times, only living bacterial cells are vulnerable. Single-step treatments at higher temperatures (>121 \({}^{\circ}\)C) or at higher pressure levels (>800 MPa) can kill pathogens and inactivate spores as well. On the other hand, the combination of pressure (500-900 MPa) and heat (90-120 \({}^{\circ}\)C) is required to inactivate bacterial spores [27]. The application of heat at slightly elevated pressure values (2-300 kPa) is widely used as a sterilization process for medical or waste treatment purposes. Examples can be found for pressure-assisted thermal sterilization of foods, aiming to inactivate bacterial spores [27; 28; 29; 30; 31]. [PERSON] and [PERSON] [32] reviewed the safety aspects of the HHP processing, mentioning the \"intelligent combination of pressure (600-800 MPa) and high temperature (60-90 \({}^{\circ}\)C)\". Researchers and engineers are facing several technical difficulties in implementing the simultaneous application of heat and pressure treatment (process control, seals and leakage in the unit, and more intensive check intervals). Moreover, these types of treatment are often inappropriate when speaking of minimal processing techniques aiming to preserve fresh organoleptic character and high nutritional value. It is essential to find the right balance between preservation goals and an acceptable level of quality damage due to the different treatments applied. Little research has been recently published within the scope of the combined heat and pressure treatment. [PERSON] et al. [33] investigated the texture of chicken breast; [PERSON] et al. [34] prepared and tested pressurized sous-vide cooked salmon; [PERSON] et al. [35] studied wine-marinated ready-to-eat shrimp treated by HHP; [PERSON], et al. [36] researched pineapple; [PERSON] et al. [37] investigated sous-vide cooked seabream; [PERSON] et al. [38] measured the characteristics of combined thermal--HHP treated pork; [PERSON] et al. [39] treated beef steak intended to be used for sous-vide cooking; while [PERSON] et al. [40] published results on chicken batters--applying all combinations, including simultaneous heat and pressure treatment. A recent paper on beef patties focused on weight loss, color and texture parameters, and the optimum values (\({}^{\circ}\)C, MPa, time) for the heat and pressure treatment, but without considering the order of the procedures [41]. Consequently, the aim of this work was to study the effect of the combined sous-vide and high hydrostatic pressure treatment on the physical, chemical, and microbiological parameters of pork.