## 1 Introduction
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Solvent** & **Sample** & \begin{tabular}{c} **Extraction** \\ **Technique** \\ \end{tabular} & \begin{tabular}{c} **Analytical Method** \\ **SpectroM** **ChromM** \\ \end{tabular} & **Key Findings** & **Ref.** \\ \hline \multicolumn{6}{c}{Extraction with conventional solvents} \\ \hline \hline \multirow{7}{*}{EtOH (50\%)} & Oregonano (_Origanum_ _vulgare_) & & & \multicolumn{1}{c}{\begin{tabular}{c} The lemon balm extract had \\ the highest phenolic \\ concentration and moderate \\ antioxidant activity, along \\ with spearmint. \\ _spicata_) \\ Lemon balm \\ _(Melissa officinalis_ \\ L.) \\ Greek sag (_Salvia_ \\ post-distillation \\ solid residues of \\ medicinal and \\ aromatic plants \\ \end{tabular} } & \multirow{7}{*}{UAE} & \multirow{7}{*}{UAE} & \multirow{7}{*}{HPLC-} & \multirow{7}{*}{\begin{tabular}{c} The lemon balm extract had \\ the highest phenolic \\ concentration and moderate \\ antioxidant activity, along \\ with spearmint. \\ \end{tabular} } \\  & & & & \multicolumn{1}{c}{\begin{tabular}{c} In the roscenary and Greek \\ sag extracts, the primary \\ recognized compounds were \\ rosmarinic acid, carnosol, \\ and carnostic acid, whereas \\ in the Greek oregano, \\ spearmint, and lemon balm \\ extracts, there were \\ salvianic acid isomers and \\ rosmarinic acid. \\ \end{tabular} } \\  & & & & \multicolumn{1}{c}{\begin{tabular}{c} The high antioxidant activity \\ had nettle extracts prepared \\ by UAE using water as a \\ solvent in a shorter time. \\ \end{tabular} } \\ \hline \hline \multirow{7}{*}{EtOH (60\%)} & \multirow{7}{*}{\begin{tabular}{c} UAE \\ (_Ltrica dioca_) \\ stirring \\ \end{tabular} } & \multirow{7}{*}{\begin{tabular}{c} UAE \\ TSE \\ TSE without \\ stirring \\ \end{tabular} } & \multirow{7}{*}{\begin{tabular}{c} TPC \\ DPPH \\ ABTS \\ \end{tabular} } & \multirow{7}{*}{\begin{tabular}{c} The high antioxidant activity \\ had nettle extracts prepared \\ by UAE using water as a \\ solvent in a shorter time. \\ \end{tabular} } \\  & & & & & \multicolumn{1}{c}{\begin{tabular}{c} The UMAE was an effective, \\ simple, and rapid method \\ for extracting \\ proanthocyanidins from \\ chokeberry with excellent \\ antioxidant activity \\ compared with the other \\ extraction techniques. \\ The main proanthocyanidins \\ in purified chokeberry \\ proanthocyanidins were \\ B-type procyanidins, \\ including procyanidin B2, B5 \\ dimer, and procyanidin C1 \\ trimer, with a degree of \\ polymerization of 14. \\ \end{tabular} } \\ \hline \hline \multirow{7}{*}{H\({}_{2}\)O (distilled)} & \multirow{7}{*}{Rapeseed meal} & \multirow{7}{*}{UAE} & \multirow{7}{*}{\begin{tabular}{c} TPC \\ TSE \\ \end{tabular} } & \multirow{7}{*}{\
\begin{tabular}{c} HPLC- \\ PAD \\ DAD \\ \end{tabular} } \\  & & & & \multicolumn{1}{c}{
\begin{tabular}{c} Rapeseed meal extracts \\ prepared by UAE revealed \\ higher TPC and FRAP \\ values than those obtained \\ with the TSE. \\ Phenylacetic acid and ferulic \\ acid were the most \\ predominant phenolic \\ compounds in these extracts. \\ \end{tabular} } \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._Some researchers optimized extraction process parameters to improve the efficiency of antioxidants from plant materials based on response surface methodology (RSM) [7; 13; 20; 22; 23]. RSM is a statistical tool that can optimize extraction conditions. The quantitative data from the appropriate experimental design are used to evaluate multiple parameters of complex extraction procedures and their interactions by generating less laborious and time-consuming mathematical models. On the other hand, only a few reports on applications of DESs in the extraction of phenolic compounds from buckwheat hull and chokeberry pomace were noted [11; 27].