## 3 Results and Discussion
### Optimization of Extraction Procedure to Obtain Phenolic Rich Fraction  
To determine the optimal extraction conditions for obtaining a fraction rich in low molecular phenolics the percentage content of specific compounds in the total yield of the obtained extract were considered. Water is the most environmentally friendly solvent with good swelling properties. However, the extraction efficacy of the main strawberry phenolic components using pure water was poor. Phenolic compounds content was very low or they were absent (Figure S2). Despite the ultrasound, or microwave treatment facilitating the release of various metabolites from the plant matrix, the low solubility of tilioside and ellagic acid proved to be the main cause of low efficiency in isolation using water. In further steps, increasing concentrations of ethanol in water were tested. Ethanol was chosen as the extraction solvent since this solvent is allowed for cosmetic purposes, thus eventual residues in the dried extract are permitted. Furthermore, ethanol is easy to evaporate and can be reused in the extraction process. As expected, the amount of phenolics increased with the rising concentration of ethanol, and only at a concentration above 70% the isolation of the considered metabolites was effective. The effectiveness of isolating a specific component using ultrasonic-assisted extraction was shown in Figure S3. Table 2 displays the results regarding quantitative determination of the main low molecular weight phenolics using maceration with stirring and extraction assisted by heating, ultrasound and microwaves. \begin{table}
\begin{tabular}{l l l l l l} \hline \hline \multicolumn{1}{c}{\(\mathbf{R_{T}}\) (min)} & \multicolumn{1}{c}{\(\mathbf{[M-H]^{-}}\)} & \multicolumn{1}{c}{**Formula**} & \multicolumn{1}{c}{**Name**} & \multicolumn{1}{c}{**Seeds Defatted at**} & \multicolumn{1}{c}{**Seeds Defatted at**} \\  & & & & **230 PSI (mg/100 g)** & **330 PSI (mg/100 g)** \\ \hline
7.73 & 451.12448 & C\({}_{21}\)H\({}_{24}\)O\({}_{11}\) & catechin hexoside 2 & 8.7 \(\pm\) 1.1 \({}^{\mathrm{a}}\) & 9.1 \(\pm\) 1.2 \({}^{\mathrm{a}}\) \\
10.07 & 577.13615 & C\({}_{30}\)H\({}_{26}\)O\({}_{12}\) & Procyanidin 2 & + & + \\
10.41 & 289.07211 & C\({}_{15}\)H\({}_{14}\)O\({}_{6}\) & Catechin 1 & 5.6 \(\pm\) 0.6 \({}^{\mathrm{a}}\) & 6.1 \(\pm\) 0.7 \({}^{\mathrm{a}}\) \\
13.68 & 517.09892 & C\({}_{24}\)H\({}_{22}\)O\({}_{13}\) & pelargonidin-3-(malonyl)-glucoside 2 & 4.4 \(\pm\) 0.5 \({}^{\mathrm{a}}\) & 4.1 \(\pm\) 0.5 \({}^{\mathrm{a}}\) \\
17.70 & 447.05881 & C\({}_{20}\)H\({}_{16}\)O\({}_{12}\) & ellagic acid rhamnside 1 & 3.6 \(\pm\) 0.3 \({}^{\mathrm{a}}\) & 4.4 \(\pm\) 0.4 \({}^{\mathrm{b}}\) \\
18.00 & 300.99905 & C\({}_{14}\)H\({}_{6}\)O\({}_{8}\) & ellagic acid 1 & 65.8 \(\pm\) 5.9 \({}^{\mathrm{a}}\) & 77.2 \(\pm\) 6.8 \({}^{\mathrm{b}}\) \\
18.44 & 463.08843 & C\({}_{21}\)H\({}_{20}\)O\({}_{12}\) & quercetin glucoside 1 & 8.1 \(\pm\) 0.8 \({}^{\mathrm{a}}\) & 10.3 \(\pm\) 0.6 \({}^{\mathrm{a}}\) \\
20.07 & 447.09445 & C\({}_{21}\)H\({}_{20}\)O\({}_{11}\) & kaempfer glucoside 1 & 23.5 \(\pm\) 2.2 \({}^{\mathrm{a}}\) & 24.9 \(\pm\) 2.4 \({}^{\mathrm{a}}\) \\
20.55 & 461.07357 & C\({}_{21}\)H\({}_{18}\)O\({}_{12}\) & methylallelagic acid hexoside 2 & 3.8 \(\pm\) 0.4 \({}^{\mathrm{a}}\) & 4.9 \(\pm\) 0.5 \({}^{\mathrm{b}}\) \\
26.32 & 593.13207 & C\({}_{30}\)H\({}_{26}\)O\({}_{13}\) & tilioside 1 & 131.7 \(\pm\) 11.6 \({}^{\mathrm{a}}\) & 136.4 \(\pm\) 12.1 \({}^{\mathrm{a}}\) \\ \hline \hline \end{tabular}  
* Components were confirmed by comparison with standard; 2 components were identified based on parent ion mass and data found in the literature; the different letter symbols indicate statistically significant differences between the values in the same line.  
\end{table} 
Table 1: Data used for identification and the results of quantification of low molecular weight phenolics (mg/100 g of fresh plant material \(\pm\) SD) extracted from defatted seed residues using 230 and 330 PSI.