## 3 Results and Discussion
It is also likely that a change in pH could contribute to a reduction in the degree of degradation of the polyphenols contained in snacks made from maize semolina with added cocoa and flaxseed pomace, which would increase their antioxidant activity and contribute to a reduced risk of development of heart disease and certain types of cancer among consumers of these products [31]. Another important feature describing the quality of snacks, which significantly affects their assessment by consumers, is their expansion ratio. Customers search for products with a light and delicate structure and therefore a large and even expansion. The highest expansion ratio was determined in the snacks produced without cocoa and without flaxseed pomace (3.09), while the lowest one was recorded in the snacks with cocoa and with 15% of golden flaxseed pomace (Table 2, Figure 2a,b). Comparing the results obtained, it was found that the only factor that had a statistically significant impact on the expansion ratio of the products was the level of flaxseed pomace addition, whereas such an effect was not confirmed for flaxseed variety. With the increasing amount of pomace in the formula of the extruded mixture, the expansion ratio of the snacks decreased, but this difference was statistically significant only in the products with at least 10% pomace addition (Table 2, Figure 2a,b). Similar results were obtained by other authors [6; 25]. The decrease in the expansion ratio noted in the sample containing flaxseed pomace is due to an increase in the amount of fiber (provided with the pomace) [6; 32; 33; 34]. Many authors who studied the effect of fiber content on the expansion ratio concluded that the addition of flaxseed pomace significantly increased the contents of all fiber fractions, which during the extrusion process forms a highly viscous and complex network with starch, reducing the stretching ability of air bubbles in the extruded material, which consequently led to a decrease in the expansion ratio [6]. Flaxseed pomace also has a high content of non-extruded oil, which reduces the friction forces inside the extruder, thereby contributing to an additional reduction in the expansion ratio [6; 12; 35; 36]. [PERSON] and others also point to the formation of lipid complexes with starch and protein as another factor that reduces the expansion ratio of snacks [35]. This fact is confirmed by the results achieved in the present study (Table 2), where the expansion ratios of the snacks were lower than the results reported by other authors analyzing the expansion of products with high-fiber additives but without a lipid component [37]. There were no statistically significant differences in the expansion ratio of the snacks produced with the pomace from the studied flaxseed varieties, despite the fact that the pomace of common flaxseed contains more ballast substances compared to golden flax pomace (Figure 2a). The reduction in the expansion ratio of the common flaxseed products having a higher fiber content is probably comparable to the decrease in this ratio caused by the higher protein content of products made with the addition of pomace from golden flax varieties [2; 6]. Table 2 presents values of the selected mechanical properties of the produced snacks (minimum force needed to break the extrudate and deformation determined at the time of snack breaking). The analysis of the influence of the factors examined in the study on the mechanical properties of the snacks showed no significant correlation between these parameters and the variety of the pomace used. In the case of snack deformation at breaking, there was no statistically significant effect of cocoa addition on this parameter. On the other hand, a statistically significant decrease in the value of the minimal breaking force was noted in the cocoa-added snacks compared to the snacks produced without cocoa.