## 3 Results and Discussion
### Total Phenolic Content (TPC) and Antioxidant Properties  
The TPC and antioxidant activities of the wheat flour, mushroom lyophilistates, and shortbread cookies enriched with button and oyster mushroom powders are presented in Figure 2.  
room species, the button mushroom, after _Boletus edulis_, had the highest polyphenol content, while the oyster mushroom had lower phenolic concentrations.  
Our results regarding the increase in TPC and the antioxidant properties of cookies enriched with mushroom powders are in agreement with the results presented in other articles. Enrichment with _C. militaris_ powder positively affected the TPC and antioxidant activity (FRAP, DPPH and ABTS assay) of cookies with 1%, 3%, and 5% mushroom powder but there was no significant difference between the control and cookies with 1% _C. militaris_[22]. [PERSON] et al. [6] reported that in cookies in which wheat flour was replaced with _C. indica_ powder in amounts from 5% to 20%, significantly (\(p<0.05\)) higher content of polyphenols and flavonoids was noted, and the highest values observed were 17.53 mg GAE/g dw and 0.42 ug quercetin/g dw for cookies with 20% _C. indica_, while for the control sample, 6.26 mg GAE/g dw and 0.14 ug quercetin/g dw were recorded, respectively. The authors also observed an increasing trend in the level of antioxidant activity according to DPPH and FRAP assays for cookies with increasing content of _C. indica_ powder. In another study [31], replacing barley flour with _A. bisporus_ flour (from 10% to 50%) significantly increased the amount of TPC (from 53.36 to 71.12 mg GAE/g, respectively) compared with control cookies (49.23 mg GAE/g). In the same work, it was reported that cookies with a higher content of mushroom powder were characterized by higher DPPH scavenging activity and reducing power.  
The increase in the TPC of mushroom-enriched cookies may be the result of the presence of the mushroom fiber, which limits the release of bound phenolic compounds [72]. Polyphenolic compounds tend to bind with polysaccharides, which largely affects the antioxidant properties of the polysaccharide fraction of mushrooms [116]. In turn, [PERSON] and [PERSON] [117] write that thermal processing of food results in both the release of insoluble bound polyphenols and the breakdown of polyphenols under the influence of high temperature. The rise in antioxidant activity in bakery products enriched with mushroom powder may be the result not only of larger amounts of antioxidant compounds such as polyphenols or flavonoids present in greater amounts in mushrooms than in the base flour but also the  
Figure 2: Total polyphenol content (TPC) (in mg GAE/g dw) and antioxidant properties (FRAP, DPPH) (in \(\upmu\)mol TE/g dw) of **(a)** mushroom powders, wheat flour, and **(b)** shorthead cookies. a––different letters between bars of the same color mean that there are significant differences between mean values ([PERSON]’s test; \(p<0.05\); \(n=3\)); Ab—_A. bisporus_; Po—_P. ostreatus_; control—cooks with 100% wheat flour; Ab2—cooks with 2% _A. bisporus_ lyophilisolate as a flour substitute; Ab4—cooks with 4% _A. bisporus_ lyophilisolate as a flour substitute; Ab6—cooks with 6% _A. bisporus_ lyophilisolate as a flour substitute; Po2—cooks with 2% _P. ostreatus_ lyophilisolate as a flour substitute; Po4—cooks with 4% _P. ostreatus_ lyophilisolate as a flour substitute; Po6—cooks with 6% _P. ostreatus_ lyophilisolate as a flour substitute.  
presence other antioxidants like high-molecular brown pigments--melnoidins--formed in the Maillard reaction during the baking process [72].