## 3 Results and Discussion
### Chemical Composition of Investigated Breads
It is important to note that apart from phenolic compounds, other substances present in the breads may have contributed to their antiradical capacity. For instance, high-temperature Maillard reaction products formed during the baking process are known to possess antioxidant properties. Additionally, other antioxidant components such as carotenoids and glutathione, which were not assessed in this study, could have also contributed to the overall antioxidant activity of the breads [72; 73]. Many authors have reported the loss of polyphenols during baking [74; 75; 76] as a result of their thermolability, and in the case of phenolic acids, the effect of thermal decarboxylation of these compounds to, e.g., 4-vinyl guaiacol [74]. Losses of polyphenols, mainly flavonoids, may also be the result of a combination of several processes, i.e., oxidation, isomerization, epimerization, and their degradation, both during baking [76] and at other stages of bread production [75]. In addition, the losses of these phenolic compounds may be caused by the formation of complexes with polysaccharides and proteins [76; 77]. This is confirmed by research by [PERSON] [3], who observed the formation of polyphenol-protein and polyphenol-polysaccharides complexes, which results in lower antioxidant activity of enriched breads. That is why the form of the supplement, its quantity, and the stage of application are so important. The research in this study showed that only a 5% addition of extruded preparation from rice flour and maltodextrin with the inclusion of red potato pulp increased the content of total polyphenols and all their groups, from low-molecular phenolic acid to high-molecular flavonoids. It can therefore be speculated that this form of added preparation resulted in a certain elimination of polyphenol-protein and polyphenol-polysaccharide combinations, where polysaccharides and proteins were derived from the wheat and rye flour used for baking bread. The extruded formulation, consisting of rice flour and maltodextrin, acted as a protective coating for the polyphenols derived from potato pulp. This protective coating prevented the interaction of phenolic antioxidants with proteins and polysaccharides present in the bread through various mechanisms, including hydrophobic and ionic interactions, as well as hydrogen and covalent binding. As a result, the phenolic antioxidants were effectively preserved and retained in the bread, contributing to its overall antioxidant activity [78; 79]. However, taking into account the stage of application of the additive for the content of antioxidants and the antioxidant status of enriched breads, it was observed that the application of the additive to the dough is more advantageous than its addition to the sourdough. Most likely, the addition of the extruded preparation to the sourdough could cause hydrolysis of the coating of this preparation made of maltodextrin and rice flour by the enzymes, which results in a high concentration of sugars, rapid fermentation, and the possibility of the formation of indigestible complexes of polyphenols from the red potato pulp of these preparations with protein present in breads. Hence, the antioxidant activity of breads with preparations added to the sourdough is lower than when such preparations are added to the dough. This antioxidant activity is 3.5 times lower in breads with preparations added to the sourdough than to the dough. This would confirm an earlier study by [PERSON] et al. [3], who see the main reason for the low antioxidant activity of the products as the complexation of polyphenols with proteins into insoluble compounds.