## 3 Results and Discussion
### Chemical Composition of Investigated Breads
Most studies on polyphenol transformations during technological operations, e.g., baking, confirm the destructive effect of temperature on nutrients and bioactive compounds, including polyphenols, due to their lack of resistance to high temperature [70]. Therefore, in this research, extruded preparations of rice flour and maltodextrin with red potato pulp as a source of polyphenols were used to enrich bread with bioactive compounds. The extrusion was performed to create a shell of rice flour and maltodextrin, which makes it possible to protect the bioactive part of the preparation, which was the source of polyphenols, i.e., red potato pulp. The aforementioned preparations exhibited a rich content of beneficial compounds and demonstrated significant antioxidant activity, making them excellent sources of health-promoting substances. As already mentioned, the antioxidant status of the finished product  
Figure 2: **(a)** Differential molecular mass distributions of preparations. **(b)** Differential molecular mass distributions of polysaccharide fractions from bread crumb where preparations were added to the dough. **(c)** Differential molecular mass distributions of polysaccharide fractions from bread crumb where preparations were added to the sourdough. depends on the form of the additive, its quantity, and the stage of its application during breadmaking. In this publication, extruded preparations were added directly to the dough or applied in the sourdough fermentation step. Breads enriched with a 5% addition of the extruded preparation showed a significant increase in total polyphenol content (TPC) ranging from 6% to 750% compared to the standard bread, irrespective of the TPC determination method used (as shown in Table 11). Similarly, there was a notable increase in the content of flavonoids in these breads, ranging from 57% to 850% compared to the standard (as indicated in Table 12). However, when comparing the bread with the addition of this preparation to the dough to the sourdough, it was unequivocally found that the breads where the preparation was added to the dough were characterized by a greater amount of TPC and flavonoids. Preparations E0 PP, E30 PP, and E40 PP added to the sourdough contributed to the reduction in TPC by 18%, 25%, and 80%, respectively, compared to breads where they were added directly to the dough at the kneading stage. In the case of flavonoids, E30 PP and E40 PP added to the sourdough contributed to a reduction in the amount of these compounds by 24% and 70%, respectively, compared to bread where they were added to the dough. The exception was EOPP, which guaranteed the same level of flavonoids regardless of the stage of its application in breadmaking. Breads with the preparations added to the dough exhibited a greater amount of phenolic acid (up to six times) and flavonoids (up to four times) compared to bread where the additives were applied at the sourdough stage (Table 12). It was noted that in the case of anthocyanins, the extruded preparations did not bring the intended results in the fortified bread, as they were practically absent in the final product. This could be attributed to the instability of these compounds, particularly anthocyanins, which are known to be highly sensitive to various factors such as temperature, pH, and enzymatic activity during processing [71]. Therefore, it can be suggested that