## 4 Conclusions  
This study demonstrates the efficacy of the natural deep eutectic solvents (NADESs) as sustainable alternatives to conventional solvents for recovering diverse bioactive compounds. Notably, the choline chloride-urea system (NADES4) emerged as a particularly effective solvent, yielding _L. japonica_ extracts with elevated polyphenol levels (75.94 mg/g) and robust antioxidant capacity (451.00 mol of Trolox/g) when optimized for water content (60:40 NADES-water mixture) and process parameters (15:1 solvent ratio, 80 \({}^{\circ}\)C, 30 min). Apart from polyphenols, NADES2 exhibited superior performance in extracting betalains from betroot (179.86 mg of betanin/100 g), while NADES4 proved to be adaptable to anthocyanin-rich matrices such as chokeberry pomace. Although NADESs demonstrated limited efficacy for carotenoids compared to acetone, their tunable properties (e.g., polarity modulation through water addition) underscore their potential for polar phytochemicals. These findings establish NADESs as versatile, eco-friendly solvents capable of replacing volatile organic compounds in industrial workflows. This study advances NADES research by utilizing a comprehensive formulation and optimization strategy, evaluating the effectiveness of NADESs with a variety of polar and non-polar phytochemicals and illustrating their versatility for diverse industrial feedstocks. In contrast to studies that only compare NADESs with a single solvent, this research compares them to both water and ethanol or acetone. These improvements position NADESs as practical solvents for recovering multiple phytochemicals, connecting green chemistry innovation with commercial scalability.  
The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/app15094843/s1](https://www.mdpi.com/article/10.3390/app15094843/s1)]([https://www.mdpi.com/article/10.3390/app15094843/s1](https://www.mdpi.com/article/10.3390/app15094843/s1)), Table S1. Comparison of Response Surface Methodology (RSM) models for optimizing total phenolic content (TPC) extraction yield; Table S2. Comparison of Response Surface Methodology (RSM) models for optimizing antioxidant activity (AA); Table S3. Analysis of variance (ANOVA) for the linear-quadratic Response Surface Methodology (RSM) model regarding total phenolic content (TPC) extraction yield; Table S4. Analysis of variance (ANOVA) for the linear-quadratic Response Surface Methodology (RSM) model regarding antioxidant activity (AA); Figure S1. Approximated versus observed values from the Response Surface Methodology (RSM) model for (a) total phenolic content (TPC) and (b) antioxidant activity (AA).  
Conceptualization, B.Z.; methodology, B.Z.; validation, B.Z.; formal analysis, B.Z., C.O. and A.M.; investigation, C.O. and A.M.; resources, B.Z.; data curation, B.Z.; writing--original draft preparation, B.Z.; writing--review and editing, C.O. and A.M; visualization, B.Z.; supervision, B.Z. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
This material received no external funding.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original contributions presented in this study are included in this article. Further inquiries can be directed to the corresponding author.  
**Acknowledgments:** We sincerely acknowledge [PERSON] for her contributions to this research. Her involvement was enabled through her participation in the Erasmus+ Mobility for Traineeships program.  
**Conflicts of Interest:** The authors declare no conflicts of interest.