## 3 Results and Discussion
### Mineral Composition
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Element** & & & \\
**mg/kg dw** & & & \\ \hline Ca & 320.14 \(\pm\) 6.97 \({}^{\rm c}\) & 114.44 \(\pm\) 4.15 \({}^{\rm a}\) & 234.91 \(\pm\) 3.52 \({}^{\rm b}\) \\ Mg & 1044.99 \(\pm\) 22.84 \({}^{\rm b}\) & 1062.48 \(\pm\) 17.63 \({}^{\rm b}\) & 155.32 \(\pm\) 8.73 \({}^{\rm a}\) \\ K & 1962.06 \(\pm\) 54.20 \({}^{\rm b}\) & 15,758.11 \(\pm\) 126.65 \({}^{\rm c}\) & 231.06 \(\pm\) 10.47 \({}^{\rm a}\) \\ Na & 441.55 \(\pm\) 10.07 \({}^{\rm b}\) & 85.37 \(\pm\) 4.12 \({}^{\rm a}\) & nd \\ Fe & 34.58 \(\pm\) 2.84 \({}^{\rm b}\) & 53.34 \(\pm\) 2.29 \({}^{\rm c}\) & 6.86 \(\pm\) 0.32 \({}^{\rm a}\) \\ Zn & 56.44 \(\pm\) 1.91 \({}^{\rm b}\) & 51.44 \(\pm\) 2.58 \({}^{\rm b}\) & 5.57 \(\pm\) 0.25 \({}^{\rm a}\) \\ Cu & 36.13 \(\pm\) 2.39 \({}^{\rm c}\) & 7.13 \(\pm\) 0.09 \({}^{\rm b}\) & 1.89 \(\pm\) 0.14 \({}^{\rm a}\) \\ Mn & 5.08 \(\pm\) 0.03 \({}^{\rm c}\) & 4.42 \(\pm\) 0.14 \({}^{\rm b}\) & 3.18 \(\pm\) 0.07 \({}^{\rm a}\) \\ Se & 0.414 \(\pm\) 0.007 \({}^{\rm b}\) & 0.115 \(\pm\) 0.004 \({}^{\rm a}\) & 0.116 \(\pm\) 0.005 \({}^{\rm a}\) \\ Co & 0.061 \(\pm\) 0.003 \({}^{\rm a}\) & 0.059 \(\pm\) 0.004 \({}^{\rm a}\) & 0.060 \(\pm\) 0.001 \({}^{\rm a}\) \\ Ni & 0.184 \(\pm\) 0.008 \({}^{\rm c}\) & 0.161 \(\pm\) 0.007 \({}^{\rm b}\) & 0.127 \(\pm\) 0.003 \({}^{\rm a}\) \\ Pb & 0.029 \(\pm\) 0.006 \({}^{\rm a}\) & 0.042 \(\pm\) 0.003 \({}^{\rm b}\) & nd \\ Cd & 0.038 \(\pm\) 0.004 \({}^{\rm b}\) & 0.176 \(\pm\) 0.002 \({}^{\rm c}\) & 0.017 \(\pm\) 0.002 \({}^{\rm a}\) \\ \hline \hline \end{tabular} \({}^{a}\)=different letters in a row mean that there are significant differences between mean values ([PERSON]’s test, \(p<0.05\), \(n=3\)); nd—not detected.  
\end{table} 
Table 2: Mineral composition of wheat flour and mushroom powders. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Element** & & & & & & \\
**mg/kg dw** & & & & & & \\ \hline Ca & 371.15 \(\pm\) 13.79 \({}^{\rm a}\) & 373.52 \(\pm\) 14.13 \({}^{\rm a}\) & 370.11 \(\pm\) 10.12 \({}^{\rm a}\) & 378.13 \(\pm\) 14.83 \({}^{\rm a}\) & 363.81 \(\pm\) 13.64 \({}^{\rm a}\) & 363.11 \(\pm\) 19.88 \({}^{\rm a}\) & 356.95 \(\pm\) 13.66 \({}^{\rm a}\) \\ Mg & 112.09 \(\pm\) 6.78 \({}^{\rm a}\) & 123.77 \(\pm\) 3.73 \({}^{\rm a}\) & 137.97 \(\pm\) 6.96 \({}^{\rm b}\) & 152.78 \(\pm\) 8.04 \({}^{\rm a}\) & 119.78 \(\pm\) 9.85 \({}^{\rm a}\) & 127.65 \(\pm\) 10.54 \({}^{\rm a}\) & 142.00 \(\pm\) 9.87 \({}^{\rm b}\) \\ K & 81.52 \(\pm\) 4.40 \({}^{\rm a}\) & 94.89 \(\pm\) 5.00 \({}^{\rm a}\) & 100.46 \(\pm\) 6.83 \({}^{\rm a}\) & 123.66 \(\pm\) 11.68 \({}^{\rm a}\) & 203.14 \(\pm\) 18.10 \({}^{\rm b}\) & 322.25 \(\pm\) 28.04 \({}^{\rm a}\) & 408.79 \(\pm\) 2.85 \({}^{\rm a}\) \\ Na & nd & nd & nd & nd & nd & nd \\ Fe & 6.99 \(\pm\) 0.13 \({}^{\rm a}\) & 7.37 \(\pm\) 0.51 \(\pm\) 0.46 \({}^{\rm a}\) & 8.75 \(\pm\) 0.34 \({}^{\rm b}\) & 7.82 \(\pm\) 0.29 \({}^{\rm a}\) & 8.88 \(\pm\) 0.19 \({}^{\rm a}\) & 9.69 \(\pm\) 0.53 \({}^{\rm a}\) \\ Zn & 6.99 \(\pm\) 0.08 \({}^{\rm a}\) & 8.33 \(\pm\) 0.06 \({}^{\rm b}\) & 9.40 \(\pm\) 0.32 \({}^{\rm a}\) & 10.73 \(\pm\) 0.46 \({}^{\rm a}\) & 7.97 \(\pm\) 0.18 \({}^{\rm b}\) & 9.00 \(\pm\) 0.43 \({}^{\rm a}\) & 102.1 \(\pm\) 0.49 \({}^{\rm165-2300 mg/kg dw; and for Na it was from 240-957 mg/kg dw and 250-1440 mg/kg dw, for _A. bisporus_ and _P. ostreatus_, respectively. According to EU regulations [60; 77], the condition for using the \"source of mineral/s\" nutritional claim is a content of at least 15% of the RDA of a given ingredient. In turn, the nutritional claim \"high mineral/s\" can only be used if the product contains at least twice the value of products marked as a \"source of mineral/s\". Taking into account the moisture content of the mushroom powders used in our tests, it can be concluded that in the case of _A. bisporus_ flour, the nutritional claims \"source of Mg, Mn, and Se\" and \"high Fe, Zn, Cu\" can be used, and in the case of oyster mushroom flour, the nutritional claims \"source of Mg, Mn, Se, and K\" and \"high Fe, Zn, Cu\" can be used.