## 3 Results and Discussion
### Effect of Degassing of Film-Forming Solutions on the Matrix and Surface of Edible Films  
The effect of degassing on the structure of the films was discussed in the example of films obtained from composite gelatine solutions with the addition of pumpkin puree. Figure 5 shows a comparison of the surface structure of edible films from composite 4%-gellate solutions (PGEL_4) with the addition of pumpkin purée at 300\(\times\) magnification, performed in an electron microscope. Due to the large accumulation of bubbles on the surface of the films obtained from non-degassed gelatine solutions with the addition of pumpkin purée, it was not possible to capture clear contours of the bubbles on the film surface. Pumpkin purée particles are visible on the surface of the edible films, both degassed and non-degassed. The photos also show that the edible films of the non-degassed solution (Figure 5A,C) have a distinctly uneven surface compared to the edible film of the degassed solution (Figure 5B,D), which has a smooth surface. The presence of air bubbles in the edible film is notable just below the surface of the edible film (Figure 5C). This occurrence can likely be attributed to the conditioning process of the poured film-forming solution during the formation of the edible film. As the film-forming solution is prepared, bubbles accumulate and move toward the free surface. However, once the solution solidifies and forms a layer on the upper part of the film, these bubbles become trapped. They are unable to rupture on the free surface due to their contact with the external environment, along with the influence of physical parameters, such as viscosity, density, pressure, and humidity. In contrast, during the degassing process under reduced pressure, as illustrated in Figure 5B,D, the bubbles are able to escape and crack on the free surface. Pumpkin purée particles are only on the  
Figure 5: Structure of films obtained on the basis of composite 4% gelatine solutions (PGEL_4) with the addition of pumpkin pure: (**A**) film surface before degassing, (**B**) after degassing, (**C**) film cross-section before degassing, (**D**) after degassing. Magnification 300 times. surface and bottom of the film--they do not affect the matrix of either film from degassed or non-degassed solutions. It is worth noting that puree particles are not present in the inner surfaces of the bubbles. Figure 6 shows a comparison of the surface of films made of composite 8% gelatine solutions (PGEL_8) with the addition of pumpkin puree, non-degassed (Figure 6A,C), and degassed (Figure 6B,D). In order to visualize the presence of pumpkin puree particles on the surface, a binarized image of the microscopic structure of the films was presented. On the surface of the film from the degassed (Figure 6B,D) 8% gelatine solution (PGEL_8), significantly larger clusters of pumpkin puree particles are visible, which is not observed in such an amount on the surface of the film from the non-degassed solution (Figure 6 A,C). The reason may be that degassing was performed using a vacuum dryer, and the pressure used to deaerate the gelatine solutions may cause the particles to agglomerate  
Figure 6: Structure of films obtained on the basis of composite 8% gelatine solutions (PGEL_8) with the addition of pumpkin puree: (**A**)—film surface before degassing, (**B**)—after degassing—magnification 300 times, (**C**)—film cross-section before degassing, (**D**)—after degassing.—magnification 1800 times; (**E**)—macro matrix surface of films made on the basis of composite gelatine solutions with the addition of pumpkin puree. into larger agglomerates, whereas, at higher magnifications (Figure 6C,D), the structure of the surface of the pumpkin puree particles can be observed. The structure of the pure particles after degassing the film-forming solution is characterized by a clearly more folded and porous structure (Figure 6D) compared to particles on the surface of the film-forming solution not subjected to degassing under reduced pressure (Figure 6C).