## 4 Conclusions  
Conventional extraction (CEM), as well as microwave-assisted extraction (MAE) of dried rosmenary leaves, were performed, and the extracts were evaluated for their total phenolic content and DPPH radical scavenging ability. The water content of the hydroethanolic solvent seemed to play a critical role in the phenolic components extracted from rosmenary. A higher TPC was not accompanied by a higher antioxidant activity when the latter was evaluated by the DPPH assay, probably because of the ability of non-phenolic compounds to provide a positive reaction with the Folin-Ciocalteau reagent. Microwave-assisted  
\begin{table}
\begin{tabular}{c c c c} \hline \multirow{2}{*}{**Extraction Method**} & **C\({}_{\text{e}}\) (mg g\({}^{-1}\)** & **k (g\({}^{-1}\) Rosemary\(\cdot\)mg\({}^{-1}\)** & **h (mg\(\cdot\)g\({}^{-1}\) Rosemary\(\cdot\)mg\({}^{-1}\)** \\  & **Rosemary)** & **min\({}^{-1}\))** & **Rosemary\(\cdot\)min\({}^{-1}\))** \\ \hline CEM 50\% \(v/v\) ethanol & 7.9 & \(3.3\times 10^{-3}\) & \(2.1\times 10^{-1}\) \\ \hline \multicolumn{4}{c}{(R\({}^{2}\) = 0.998, \(p\) \(<\) 0.0001)} \\ \hline EAE + CEM & 21.2 & \(2.6\times 10^{-4}\) & \(1.2\times 10^{-1}\) \\ \hline \multicolumn{4}{c}{(R\({}^{2}\) = 0.998, \(p\) \(<\) 0.0001)} \\ \hline \end{tabular}
\end{table}
Table 6: Kinetic parameters of conventional extraction and EAE + CEM.  
Figure 4: Effect of extraction time on TPC during (\(\Circuit\)) conventional extraction (50% \(v/v\) ethanol) and (\(\bullet\)) EAE + CEM. Dashed lines are the non-linear fitting curves (Equation (2)).  
extraction seemed to favor the selective extraction of phenolic compounds from rosmary; thus, in this case, the extract with the higher TPC showed the best antioxidant activity.  
Enzymatic assisted extraction (EAE) as a pretreatment method to a solid-liquid conventional extraction (CEM) is a promising process for the efficient extraction of phenolic phytochemicals from dried rosmary leaves. The extraction of phenolic compounds was found to depend on various parameters, including ethanol/water ratio, enzyme type, enzyme over raw material ratio, and extraction time. The pretreatment of rosmary leaves with pectinolytic enzymes for 1 h hydrolyzed the cell wall polysaccharides, thus significantly enhancing the phenolic yield obtained from the subsequent hydroethanolic conventional extraction. Application of an enzyme complex consisting mainly of pectinases followed by conventional extraction with ethanol/water 1:1 \(v/v\) increased the extraction efficiency by at least 30%.  
In the case of rosmary leaves, EAE in combination with CEM was able to achieve extracts of better quality as compared to the extracts obtained only from CEM. This advantage can compensate, to a certain extent, for the cost when scale-up is the goal, and this greener approach can be considered as a useful complement to conventional extraction for obtaining high added-value extracts.  
Conceptualization, D.M. and A.D.; Data curation, A.R.N.P., L.P.-T. and T.L.; Investigation, A.R.N.P. and L.P.-T.; Methodology, A.R.N.P., L.P.-T. and T.L.; Project administration, D.M. and A.D.; Resources, D.M., D.K. and A.D.; Writing--original draft, A.R.N.P., L.P.-T., T.L., D.M. and D.K. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
A.R.N.P. would like to thank the General Secretariat for Research and Technology (GSRT) and the Hellenic Foundation for Research and Innovation (HFRI) for funding her PhD research. The authors would like to thank Novozymes A/S (Bagswaerd, Denmark) for supplying the enzymes used in the study.  
The authors declare no conflict of interest.