## 4 Conclusions  
_A. bisporus_ and _P. ostreatus_ lyophilistates were characterized by higher amounts of basic nutrients, polyphenol compounds, elements (K, Mg, Na, Fe, Zn, Cu, Ni) compared with wheat flour. At the same time, the content of Pb and Cd was below the maximum safe limits set by EU regulations. The use of the lyophilistates as a partial substitute (2-6%) for wheat flour in shorthead cookies contributed to a significant (_p_ < 0.05) increase in the amounts of selected elements, protein, and ash in all versions of the cookies. Moreover, samples with fiber above 3 g/100 g (Ab2, Ab4, Po2) and above 6 g/100 g (Ab6, Po4, Po6) were obtained, which would allow the use of \"source of/high in fiber\" nutrition claims.  
The results presented in this study show that substituting a small amount (2-6%) of wheat flour with mushroom lyophilises affects the functional properties of composite flours as well as the finished products. The values of the functional parameters of blended flours compared with the base flour were significantly (\(p<0.05\)) lower for BD and higher for OHC for all blended flour versions, higher for WSI for flours with the addition of 4-6% mushroom powders, and higher for WHC for flours with 4% and 6% addition of oyster mushroom lyophilise. The values of basic parameters of cookies such as weight, thickness, and spread ratio of enriched cookies did not differ statistically (\(p<0.05\)) from the control samples. In turn, the values of the \(\mathrm{a_{w}}\) parameter were lower. With the increase in the addition of mushroom lyophilise, the L* value was significantly lower, while the value of the parameter \(\mathrm{a^{*}}\) (redness) increased. Higher \(\mathrm{\Delta E}\) and BI were recorded for the cookies with _A. bisporus_. Cookies with 6% mushroom powders (Ab6, Po6) were characterized by significantly higher hardness. The results of the sensory evaluation clearly indicate that among the analyzed versions of the cookies, the highest scores were given to samples with the addition of oyster mushroom, while the lowest scores were given to cookies with the addition of button mushrooms.  
To sum up, the blending of wheat flour with oyster mushroom lyophilise up to 6% seems to be a compromise between obtaining products with improved nutritional composition and maintaining sensory quality and acceptance by consumers.  
Conceptualization, A.S.; methodology, A.S., E.J.-R. and W.G.; software, A.S. and W.G.; validation, A.S., E.J.-R. and W.G.; formal analysis, A.S., E.J.-R. and W.G.; investigation, A.S., E.J.-R. and W.G.; resources, A.S. and E.J.-R.; data curation, A.S. and W.G.; writing--original draft preparation, A.S.; writing--review and editing, A.S.; visualization, A.S. and E.J.-R.; supervision, A.S.; project administration, A.S.; funding acquisition, E.J.-R. All authors have read and agreed to the published version of the manuscript.  
Project financed under the program of the Minister of Education and Science under the name \"Regional Initiative of Excellence\" in 2019-2023, project number 029/RID/2018/19, funding amount PLN 11.927.330.00.  
Not applicable.  
The data used to support the findings of this study can be made available by the corresponding author upon request.  
The authors declare no conflicts of interest.