## 3 Results and Discussion
### Effects of Domestic Cooking on Changes in the TPC, TFC and Antioxidant Activities of Faba Leaves  
The effects of domestic cooking on changes in the TPC, TFC, and antioxidant activities of faba leaves are shown in Figure 3. The TPC was 44.26 mg GAE/g d.w. in freeze-dried faba leaves (Figure 3A). For the cooked leaves, only the microwaving treatment significantly increased TPC (57.56 mg GAE/g d.w.) compared with the other treatments. The increased \(\iota\)-dopa content after the microwaving treatment was probably responsible for this result (Figure 2A); however, there were no significant differences in TPC between the steamed and freeze-dried faba leaves, with even a short steaming time also increasing the \(\iota\)-dopa content (Figure 2B). This might be explained by a reduction in the polyphenol compounds that are relatively sensitive to steaming [28]. The roasting treatment maintained the level of TPC, but the boiling treatment decreased it (Figure 3A). These results were consistent with those observed in the changes in \(\iota\)-dopa content (Figure 2B,D). Overall, a high positive correlation (0.958) was observed between the \(\iota\)-dopa content and TPC (Table S1). The roasting treatment increased the TPC of faba leaves (45.73 mg CE/g d.w.) compared with freeze drying (32.02 mg CE/g d.w.), whereas the other cooking methods \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Flavonols**} & \multirow{2}{*}{**Glycosides**} & \multicolumn{5}{c}{**Domestic Cooking Methods**} \\ \cline{3-6}  & & **FD** & **MW** & **RT** & **SM** & **BL** \\ \hline \multirow{8}{*}{K-G} & 3-rho & 0.22 \(\pm\) 0.02 a & 0.18 \(\pm\) 0.01 a & 0.22 \(\pm\) 0.05 a & 0.18 \(\pm\) 0.01 a & 0.15 \(\pm\) 0.01 a \\  & 3-rho-glc-7-rho-4\({}^{\prime}\)-rha & 0.34 \(\pm\) 0.03 a & 0.29 \(\pm\) 0.03 a & 0.31 \(\pm\) 0.08 a & 0.29 \(\pm\) 0.03 a & 0.22 \(\pm\) 0.02 a \\  & 3-gal-7-rha & 0.39 \(\pm\) 0.04 a & 0.36 \(\pm\) 0.02 a & 0.41 \(\pm\) 0.04 a & 0.36 \(\pm\) 0.02 a & 0.35 \(\pm\) 0.03 a \\  & 3-rha-gal (glc)-7-rha & 0.94 \(\pm\) 0.07 b & 0.89 \(\pm\) 0.03 b & 1.21 \(\pm\) 0.06 a & 0.89 \(\pm\) 0.03 b & 0.72 \(\pm\) 0.00 b \\  & 3-rha-ara-7-rha & 1.78 \(\pm\) 0.27 a & 1.79 \(\pm\) 0.12 a & 1.85 \(\pm\) 0.38 a & 1.79 \(\pm\) 0.12 a & 1.39 \(\pm\) 0.02 a \\  & 3-ara-7-rho & 4.78 \(\pm\) 0.52 a & 4.40 \(\pm\) 0.12 b & 6.13 \(\pm\) 0.37 a & 4.40 \(\pm\) 0.12 b & 2.83 \(\pm\) 0.15 c \\  & 3-acetyl-rha-gal-7-rha & 0.41 \(\pm\) 0.03 ab & 0.48 \(\pm\) 0.06 ab & 0.63 \(\pm\) 0.06 a & 0.48 \(\pm\) 0.06 ab & 0.29 \(\pm\) 0.03 b \\  & 3-rha-7-rho + un & 3.40 \(\pm\) 0.24 a & 3.18 \(\pm\) 0.06 a & 3.90 \(\pm\) 0.66 a & 3.18 \(\pm\) 0.06 a & 1.56 \(\pm\) 0.08 b \\  & 3-acetyl-gal-7-rho & 0.71 \(\pm\) 0.10 a & 0.83 \(\pm\) 0.06 a & 0.75 \(\pm\) 0.14 a & 0.83 \(\pm\) 0.06 a & 0.51 \(\pm\) 0.04 a \\ \hline \multirow{2}{*}{Q-G} & 3-rho-glc & 0.07 \(\pm\) 0.00 a & 0.09 \(\pm\) 0.01 a & 0.07 \(\pm\) 0.01 a & 0.09 \(\pm\) 0.01 a & 0.06 \(\pm\) 0.02 a \\  & 3-rha-gal (glc)-7-rha & 0.12 \(\pm\) 0.01 b & 0.17 \(\pm\) 0.01 a & 0.15 \(\pm\) 0.01 ab & 0.17 \(\pm\) 0.01 a & 0.15 \(\pm\) 0.00 ab \\  & 3-rha-ara-7-rho & 0.06 \(\pm\) 0.01 b & 0.12 \(\pm\) 0.01 a & 0.07 \(\pm\) 0.00 b & 0.12 \(\pm\) 0.01 a & 0.10 \(\pm\)0.01 ab \\ \hline \end{tabular} Values are averages with standard errors from triplicate experiments. Different letters within the same line indicate significant differences at \(p<0.05\) ([PERSON]’s HSD test). Abbreviation: K-G, kaempfer glycosides; Q-G, quercetin glycosides; rha, rhamnoside; rha-glc, rhamnoglucose; gal, galactoside; rho-gal, rhamnoside; rho-ara, rhamoarabinoside; un, unknown; FD, freeze dried; MW, microwaving; RT, roasting; SM, steaming; BL, boiling.  
\end{table} 
Table 2: Effect of domestic cooking on faba leaf flavonoid (flavonol) glycosides (mg of kaempferl-3-\(O\)-glucoside equivalent g \({}^{-1}\) d.w.). did not (Figure 3B). This result was consistent with the changes in the contents of flavonoid metabolites (Section 3.2).