## 3 Results and Discussions
### Evaluation of the Nutrient Content of the Analyzed Fish Dishes
#### 3.1.2 Evaluation of Macronutrient Content  
According to the working protocol, three determinations were performed, with a coefficient of variation of reproducibility of 3.85 (VCr % = 3.85) and a measurement uncertainty of 7.35 (M% = 7.35). The preparation selected for evaluation in relation to different types of heat treatment or processing is a product with high protein content of approximately 14.32 \(\pm\) 0.02%. Starting from a protein digestibility of 69.51% in sample A0 (raw), the most useful type of heat treatment is sous vide, where the digestibility increased to 89.91%. Starting from a protein digestibility of 69.51% in sample A0 (raw), the lowest digestibility for all dishes was determined for sample A3 (Mw-CS, 86.91%), with the results being significantly different (_p_ < 0.05). The results were not significantly different (_p_ > 0.05) for samples A1 (SV-CS, 89.91%), A2 (CC-CS, 89.31%), and A4 (CC-CC, 90.67%). It was also found that the digestibility of sample A5 (CC-CF) was 91.74%, a result significantly different from the other samples (_p_ < 0.05). The authors of a similar study [47] concluded that thermal processes such as sous vide can induce favorable changes, such as partial unfolding or exposure of cleavage sites, in muscle proteins and improve their digestibility, whereas processes such as stewing and roasting can induce unfavorable changes, such as protein aggregation, severe oxidation, cross linking, or increased disulfide (S-S) content and decrease the susceptibility of proteins during gastrointestinal digestion. In another study [29], following treatments such as pulsed electric field, high pressure, and ultrasound, conformational and microstructural changes in proteins were found to lead to the unfolding of polypeptides and the exposure of active sites for further interactions. These changes can increase the accessibility of digestive proteases to cleavage sites. Some of these technologies can inactivate some egg proteins that are enzyme inhibitors, such as trypsin inhibitors. Sous vide is recommended to be used in order to develop new fine dining dishes with increased protein bioaccessibility. The carbohydrate content did not undergo major changes during the treatments applied, with the observed differences being an increase of less than 1%. A0 had a sugar content of 0.73% (_w/w_). A1 (sous vide cooked) had a sugar content of 1.1% (_w/w_), A2 (convection cooked) contained 1.05% (_w/w_) sugars, and A3 (microwaved) contained 1.93% (_w/w_) sugars. The CC-CC system, A4, contained 1.23% (_w/w_) sugars, and the CC-CF system, A5, contained 1.25% (_w/w_) sugars. The raw fish dish (A0) did not have a high carbohydrate content--0.73% (_w/w_). Compared to the raw sample, the different values of carbohydrate content in the other samples were due to the solubility taken up by the liquid collected in the baking containers. The carbohydrate content was not significantly different for samples A1 (SV-CS, 1.1% (_w/w_)), A2 (CC-CS, 1.05% (_w/w_)), A4 (CC-CC, 1.23% (_w/w_)), and A5 (CC-CF, 1.25% (_w/w_)) (_p_ > 0.05). The carbohydrate content was significantly different for sample A3 (Mw-CS, 1.90% (_w/w_) (_p_ < 0.05), given the rapid heating of the dish and the evaporation of water during this time. Culinary dishes, rich in saturated and monounsaturated fats, are very resistant to heat. In the analyzed samples, the loss of lipid content ranged between 6% and 9%, depending on the applied cooking system (Table 3 shows the lipid content of all of the analyzed samples). The most protective system was the sous vide (A1) system with a 6% loss, and a 9% loss was determined for sample A3, treated with microwaves. Lipids and lipid-containing foods are particularly sensitive to microwave heating since the specific heat of lipids is low and, therefore, they are heated quickly. Microwave heating mainly favors lipid oxidation but can also cause lipolysis and polymerization. This cooking method can have a different impact on lipid oxidation depending on the treatment conditions used (power, temperature, and time).