## 3 Results and Discussion
#### 3.1.1 Impact of the Different Extraction Factors on the Extraction Yield Percentage
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Yield (\%)**} & \multicolumn{3}{c}{**TPC (ug GAE/mg DE)**} & \multicolumn{3}{c}{**TFC (ug QE/mg DE)**} \\ \hline  & **Estimated** & & & **Estimated** & & & **Estimated** & & \\  & **Regression** & **F-Value** & **\(p\)-Value** & **Regression** & **F-Value** & **\(p\)-Value** & **Regression** & **F-Value** & \(p\)**-Value** \\  & **Coefficient** & & & **Coefficient** & & & & **Coefficient** & & \\ \hline Intercept & \multirow{2}{*}{10.15} & \multirow{2}{*}{16.19} & \multirow{2}{*}{0.0034} & \multirow{2}{*}{30.87} & \multirow{2}{*}{50.88} & \multirow{2}{*}{0.0002} & \multirow{2}{*}{4.97} & \multirow{2}{*}{38.86} & \multirow{2}{*}{0.0004} \\ \((\beta_{0})\) & & & & & & & & & \\ \(X_{i}\) & \(-2.32\) & 118.75 & 0.0001 & 0.6300 & 5.25 & 0.0705 & \(-0.2350\) & 6.48 & 0.0516 \\ \(X_{j}\) & 0.6750 & 10.08 & 0.0247 & \(-0.1700\) & 0.3824 & 0.5634 & 0.2800 & 9.20 & 0.0290 \\ \(X_{k}\) & 0.6138 & 8.34 & 0.0343 & 2.54 & 85.36 & 0.0002 & 1.11 & 143.89 & \(<\)0.0001 \\ \(X_{ij}\) & \(-0.4425\) & 2.17 & 0.2010 & \(-2.14\) & 30.23 & 0.0027 & \(-0.4275\) & 10.72 & 0.0221 \\ \(X_{k}\) & \(-0.5300\) & 3.11 & 0.1382 & 2.51 & 41.60 & 0.0013 & 0.4425 & 11.49 & 0.0195 \\ \(X_{k}\) & \(-0.4025\) & 1.79 & 0.2382 & 5.12 & 173.26 & \(<\)0.0001 & 1.48 & 128.92 & \(<\)0.0001 \\ \(X_{ii}\) & \(-0.0042\) & 0.0002 & 0.9899 & 2.77 & 46.81 & 0.0010 & \(-0.7804\) & 32.98 & 0.0022 \\ \(X_{ij}\) & \(-0.0917\) & 0.0858 & 0.7813 & \(-3.26\) & 64.95 & 0.0005 & 0.2496 & 3.37 & 0.1257 \\ \(X_{ik}\) & 0.3608 & 1.33 & 0.3009 & 0.3487 & 0.7427 & 0.4282 & \(-0.1654\) & 1.48 & 0.2778 \\ Lack of Fit & & 0.3362 & 0.8059 & 1.61 & 0.4057 & 1.64 & 0.4002 \\ \(R^{2}\) & 0.9668 & & & & 0.9892 & & & 0.9859 & \\ \(R^{2}_{(aff)}\) & 0.9071 & & & 0.9698 & & & 0.9605 & \\ C.V.\% & 5.84 & & & 2.53 & & & 5.67 & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Analysis of variance (ANOVA) of the quadratic model of the response surface through the Box-Behnken Design for extraction yield, TPC, and TFC obtained by the UAE method. insignificant effects of factors in the final second-order polynomial equation for extraction yield, this response was expressed via Equation (5):  
\[Y_{yield} =-11.92167+4.60083X_{i}+0.766333X_{j}+0.345042X_{k} \tag{5}\]  
where \(Y_{yield}\) is the percentage of ultrasound-assisted extraction yield, \(X_{i}\) is the linear effect of the solid-to-liquid ratio of \(C\). _monocantha_ plant, \(X_{j}\) is the linear effect of extraction temperature, and \(X_{k}\) is the linear effect of extraction time. Figure 2: Three-dimensional response surface plots: (**a**) effect of solid-to-liquid ratio and extraction time on extraction yield; (**b**) effect of solid-to-liquid ratio and extraction temperature on extraction yield;  
(**c**) effect of solid-to-liquid ratio and extraction time on total phenolic content (TPC); (**d**) effect of solid-to-liquid ratio and extraction temperature on total phenolic content (TPC); (**e**) effect of solid-to-liquid ratio and extraction time on total flavonoid content (TFC); and (**f**) effect of solid-to-liquid ratio and extraction temperature on total flavonoid content (TFC). Figure 2a highlights a proportional linear correlation between the percentage of extraction yield and extraction time, ranging from 10 to 30 min. Extraction yields increased with increasing time. A similar correlation is reported in Figure 2b, with extraction yields increasing as the extraction temperature increases from 35 \({}^{\circ}\)C to 45 \({}^{\circ}\)C.  
These results were induced by taking into account the different physicochemical phenomena triggered. Indeed, the increase in the extraction temperature affects the chemical properties of the conjunctive and structural tissues of the studied plant matrix, which can effectively destroy the adhesion and intramolecular cohesion forces of the target molecules in the plant matrix, thus promoting the release and solubility of these molecules [81].