## 3 Results and Discussion
### The Content of Total Flavonoids  
Flavonoids, belonging to the polyphenols, are commonly found in nature as dyes. Their presence has also been found in mushrooms. The content of flavonoids per gram of dry weight of the fruiting bodies is shown in Figure 2a. Among the whole fruiting bodies, the lowest concentrations were noticed in _P. ostreatus_ and _P. enrygii_ (0.47 \(\pm\) 0.02 mg/g and 0.51 \(\pm\) 0.04 mg/g, respectively), while the highest were in _A. bisporus_ (brown) followed by _A. bisporus_ (white) (1.84 \(\pm\) 0.04 mg/g and 1.64 \(\pm\) 0.04 mg/g, respectively). The results of _A. bisporus_ support the previous findings in which their flavonoids level was recorded at ~1.7 mg/g [30]. On the other hand, [PERSON] et al. [23] reported similar amounts of flavonoids in _A. bisporus_ and _P. ostreatus_ (approximately 1 mg/g).  
Figure 1: The content of total phenolics in the extracts from caps, stems and whole fruiting bodies, expressed per fruiting body dry weight (**a**) and per extract dry weight (**b**); Abw—_A. bisporus_ (white), Abb—_A. bisporus_ (brown), Le—_L.odes,_ Pn—_P. nameko,_ Pe—_P. enrygii,_ Po—_P. ostreatus._ Mean values (\(n=3\)) with different lowercase letters show significant differences among the parts of mushrooms belonging to the same species. Mean values with different capital letters indicate significant differences among the same parts belonging to various species (\(p<0.05\), Tukey’s test).  
In the case of three species (_P. nameko, P. ostreatus_ and _P. eryngini_), flavonoids were distributed equally in the fruiting bodies. The caps of _A. bisporus_ (brown) and _L. edodes_ contained slightly higher amounts of flavonoids compared to the stems. However, in the case of the white _A. bisporus_ the difference was very stark (the concentration in the caps was almost three times higher than in the stems). This outcome is contrary to that of [PERSON] et al. [27]--who found slightly higher content of flavonoids in the stems of _A. bisporus_--but consistent with data obtained by [PERSON] and [PERSON] [26], who reported flavonoid concentration in caps at 2.173 \(\pm\) 0.007 mg/g and in stems at 1.533 \(\pm\) 0.005 mg/g.  
When the contents of total flavonoids were expressed per one gram of extract dry weight, the values were several times larger, due to the concentration of these compounds. The highest levels of flavonoids were observed in the extracts from _A. bisporus_ caps (white and brown), while much lower concentrations were observed in the extracts from _P. nameko_  
Figure 2: The content of total flavonoids in the extracts from caps, stems and whole fruiting bodies, expressed per fruiting body dry weight (**a**) and per extract dry weight (**b**); Abw—_A. bisporus_ (white), Abb—_A. bisporus_ (brown), Le—_L. edodes_, Pn—_P. nameko_, Pe—_P. eryngini_, Po—_P. ostreatus_. Mean values (\(n\) = 3) with different lowercase letters show significant differences among the parts of mushrooms belonging to the same species. Mean values with different capital letters indicate significant differences among the same parts belonging to various species (\(p\) < 0.05, Tukey’s test).  
and _P. ostreatus_ caps. Extracts from _L. edodes_ and _P. eryngii_ showed the lowest quantities, and in these cases, flavonoids were distributed equally in the fruiting bodies.