## 3 Results and Discussion
### The Effect of the Addition of Chokeberry Pomace Flour on the Quality of the Dough
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & \multicolumn{3}{c}{**Crust of Muffin**} & \multicolumn{3}{c}{**Crumb of Muffin**} \\ \cline{2-7}  & **L*** & **a*** & **b*** & **L*** & **a*** & **b*** \\ \hline Control & \(58.58\) d & \(13.35\) c & \(22.02\) d & \(69.09\) d & \(0.16\) d & \(24.18\) d \\ \(10\%\) & \(42.11\) c & \(8.12\) b & \(2.82\) c & \(36.52\) c & \(8.85\) c & \(-2.14\) c \\ \(20\%\) & \(39.14\) b & \(7.83\) a & \(-0.58\) a & \(32.41\) b & \(8.78\) bc & \(-4.53\) b \\ \(30\%\) & \(38.83\) b & \(7.78\) a & \(-0.63\) a & \(31.01\) ab & \(8.18\) ab & \(-5.81\) a \\ \(40\%\) & \(38.38\) b & \(7.68\) a & \(-1.20\) a & \(30.22\) a & \(8.04\) a & \(-6.04\) a \\ \(50\%\) & \(35.44\) a & \(6.74\) a & \(-3.54\) b & \(30.07\) a & \(7.02\) e & \(-6.45\) a \\ \hline \hline \end{tabular} a, b, c, d, e—different letters next to numbers indicate statistically significant differences.  
\end{table} 
Table 4: The color parameters of the classic muffins. In order to ascertain the textural characteristics of muffins, an analysis was conducted to determine the hardness, springiness, chewiness, and cohesiveness of the crumb (Figures 3a-d and 4a-d). Cookies texture, especially hardness, is an important physical parameter in biscuit quality evaluation, which, in turn, affects the sensory attributes of the final products [45]. The products tested, which differed in their proportion of chokeberry pomace flour, exhibited statistically significant differences in terms of the textural parameters studied. The substitution of the smallest quantity of wheat flour resulted in statistically significant changes to the texture of the gluten free muffins (Figure 4a-d). The products containing wheat flour exhibited a lower hardness (expressed as the maximum force required for the first compression), ranging from 4.87 N for the control sample to 10.50 N for the classic variant with 50% pomace flour, in comparison to the gluten-free muffins (from 9.85 N for control samples to 14.79 N for the highest proportion of pomace). Other authors have proposed that the partial substitution of traditional flour with powdered fruits and other plant additives has a negative impact on the texture of the resulting product, leading to an increase in the hardness of baked goods [27; 42; 49]. In the studies of [PERSON] et al. [27], it was shown that the hardest cookies were those with 10% raspberry pomace flour supplement (36.09 N), and the softest were those with 20% strawberry pomace flour supplement (6.43 N). Additionally, [PERSON] et al. [43] identified a correlation between the quantity of fruit pulp and the hardness of corn snacks. With regard to springiness and cohesiveness (Figure 4c,d) the gluten-free products displayed greater differentiation. Upon applying regression analysis, a biased model was obtained (R\({}^{2}\) = 0.99): cohesiveness = \(-0.127\)x + 0.936. Similar trends to those for hardness were observed for chewiness (Figures 3a and 4a). Chewiness, which is primarily related to the difficulty of chewing before swallowing, is an additional key texture parameter [51]. The highest proportion of flour (samples 50%) showed the hardest, most difficult to chew, and not very springy texture. Figure 4: The hardness (**a**), chewiness (**b**), springiness (**c**), and cohesiveness (**d**) of the gluten free muffins. a, b, c, d, e—different letters next to numbers indicate statistically significant differences.