## 3 Results and Discussion
### GC-MS Analysis of Maca Extracts  
The application of the GC-MS method enabled the comparison of the composition of extracts obtained using two various solvents: 96% ethanol and water. The chromatograms of ethanolic and water extracts are shown in Figure 4, while the GC-MS results are in Table 3. \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**No.**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**RT (min)**} & \multicolumn{2}{c}{**MS Signals *, \(m/z\)**} & \multicolumn{2}{c}{**Content **[** **[**\%**]**} \\ \cline{5-6}  & & & **[M*]\({}^{\star}\)]\({}^{+}\)** & **Characteristic** & **E** & **W** \\ \hline
1 & Benzyl nitrile & 5.82 & 117 & 90, 116, 89, 51, & & \\
2 & 5-Hydroxymethylfurfural & 8.49 & 126 & 92, 41, 43, 69, 29 & 2.6 & 6.6 \\
3 & Benzyl isothicyaniate & 10.66 & 149 & 91, 65, 92, 51, 39 & 0.2 & 0.2 \\
4 & Unknown I & 14.20 & (?) & 52, 73, 31, 43, 86 & 28.0 & 38.4 \\
5 & Unknown II & 18.50 & (?) & 117, 43, 75, 57, & 20.8 & 39.6 \\ \end{tabular}
\end{table} 
Table 3: Compounds identified in ethanolic (E) and water (W) extracts of maca (_L.__mevenii_) root extracts by the GC-MS method. Figure 4: GC-MS chromatograms of ethanolic (**a**) and water (**b**) extracts of maca (_L.__mevenii_) root (peaks numbered according to Table 3). GC-MS analysis allowed for the identification of 12 compounds present in maca extracts and for the comparison of their relative contents, although some compounds remained not identified (e.g., peaks no. 4, 5, 16). Mass spectra of three macamides characteristic of maca, which were present in ethanolic extracts, are shown in Figure 5.  
The GC-MS analyses of extracts showed that among maca components that were volatile enough and not too polar to be directly analyzed by this method, there were some nitriles, fatty acids, amides, and sterols. Analyzing the results of GC-MS analyses, it is clearly visible that using ethanol as the solvent resulted in the isolation of a wider variety of bioactive compounds than using water. Importantly, in ethanolic extracts, three compounds from the group of characteristics for maca benzylalkamides (macamides) were found: N-benzylhexadecanamide, N-benzyl-(9Z,12Z)-octadecanamide and N-benzyl-(9Z)-octadecanamide, as well as other fatty acids amides: hexadecanamide, (9Z)-octadecanamide and octadecanamide. These compounds were not extractable by water and are not present on the chromatogram of water extract shown in Figure 4, similar to hexadecanoic acid and linoleic acid. Both macamides and fatty acids derivatives are valuable bioactive compounds that were previously identified in maca by UPLC-QTOF-MS [20] and HPLC-MS [21] methods. Comparing the obtained GC-MS data, it should be pointed out that ethanolic extract also contained significant amounts of sterols: \(\beta\)-sitosterol and campesterol, which are known for their bioactive properties and pharmacological effects, including high antioxidant activity [22], while in water extract their contents were only on the trace level. Very interesting is that water extracts were characterized by significantly higher antioxidant activity, despite the absence of important bioactive compounds which were found in ethanolic extracts by the GC-MS analysis. It can be explained by the presence of water-soluble polysaccharides, being one of the main maca components characterized by high antioxidant activity, which are not soluble in ethanol [18; 19]. It should be taken into consideration that water-soluble sugars can interact with the Folin-Ciocalteu reagent, which can lead to an overestimation of the TPC results obtained for the water extracts [23].