## 3 Results and Discussion
### Influence of Heating Techniques on Texture  
The preservation and preparation of meat for consumption using high temperatures cause thermal denaturation of proteins, which leads to certain changes in the microstructure of muscle fibers and connective tissue, resulting in hardness, which is an important characteristic of meat quality [43]. Time and type of thermal treatment are the most important factors determining the desired properties of the texture.  
Chicken breast filled cooked with the sous-vide technique (C) significantly differed (\(p\) = 0.0103) from other culinary samples produced in heating devices A and B (Figure 2). The breast prepared using low-temperature treatment (C) was the softest and most juicy. Similarly, [PERSON] and others [44] and [PERSON] and [PERSON] [45] showed that cooking sous-vide reduces the hardness of the meat, making it delicate. [PERSON] and [PERSON] [45] stated that the Turkey breast processed with the sous-vide technique was characterized by the lowest hardness compared to other heat techniques used in gastronomy. During heating, the hardness of the intramuscular connective tissue changes the fragility of the meat, which depends on the method, time, and temperature of the treatment. At a temperature of about 54 \({}^{\circ}\)C, the process of forming embrittlement associated with the denaturation of contractile proteins begins. At temperatures above 60 \({}^{\circ}\)C, collagen fibers shrink and gelatinize, which, combined with the transverse destruction of myofibrils and the expansion of the space between them, leads to the formation of proper fragility. The reduction in the fragility of meat occurs at temperatures above 70 \({}^{\circ}\)C [24], which confirms the results obtained in this study.  
The highest hardness after direct preparation of meat was characterized by samples cooked by techniques A and B. The high hardness was also characterized by the braised breast in the convection-steam furnace (Br-B). The baked and fried samples showed intermediate hardness, which could be due to the use of oil during their preparation.  
Storage of poultry samples significantly affected the value of the cutting force (Table 8). Poultry samples prepared with the sous-vide C-C technique were characterized by the lowest hardness on the date of manufacture and the smallest changes in hardness during storage. About 40% higher strength was applied by testing the texture of sample Ba-B after  
Figure 2: Texture results of chicken breast filled samples expressed by cutting force. Code designations as in Table 1. Different letters A, B, C... in columns show the statistical difference (\(p\) < 0.05) related to the impact of the heating group.  
24 h storage. The force values used in the cutting test of this sample were comparable to the force used in the texture analysis of cooked samples C-A and C-B (Figure 2).  
Despite the large variation between the texture of the analyzed samples after different storage times, statistical conclusions indicated that the heating groups A and B used did not have an influence on the tested indicator. A separate homogeneous group included chicken samples prepared using the sous-vide technique. Similar conclusions were made in studies by [PERSON] et al. [46], which stated that sous-vide cooking can be a practical thermal process improving the water retention capacity and preservation of the chicken breast texture both after preparation and during 4 weeks of storage.