Microwave-assisted sustainable extraction of polyphenols from Mentha arvensis using choline chloride-glycerol-deep eutectic solvent with categorical boosting evaluation

The sustainable deep eutectic solvent (DES) demonstrates an excellent aptitude for extracting polyphenols from Mentha arvensis with microwave-assisted extraction (MAE). The categorical boosting (CatBoost) optimized phytochemical content along with antioxidant activity at irradiation time (2–6 min), microwave power (160–320 W), and biomass quantity (1–2.0 g/10 mL) with DES. The results showed total phenolic content (TPC) 117 ± 3.5 mg GAE/g, total flavonoid content (TFC) 85 ± 3.0 mg QE/g, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition 95 ± 4.0 % after 4 min at 240 W with 1.5 g biomass. The average relative errors from CatBoost demonstrated the best performance for training data points at 0.391 % for TPC, 0.521 % for TFC, and 0.201 % for DPPH. The prediction of TPC yielded an average relative error of 0.453 %, while TFC and DPPH achieved relative errors of 0.658 % and 0.381 %, respectively, through testing data analysis. The R² of 1.0 for the train, test, and complete TPC, TFC, and DPPH data showed that CatBoost predicted the results with maximum accuracy. The partial dependence and feature importance analyses highlighted the significant influence of factors in optimizing the extraction process. Permutation and model feature importance analyses revealed that time contributed the most to TPC (43.6 % and 37.2 %), microwave power had the highest influence on TFC (40.2 % and 43.9 %), and biomass was the primary contributor to DPPH (50.8 % and 50.5 %), respectively. The significant antibacterial (S. aureus = 23 ± 1.7 mm and E. coli = 21 ± 1.4 mm) and antifungal potential (F. solani = 20.5 ± 1.7 mm, A. niger = 25.5 ± 1.6 mm), were observed of optimized DES extracts. The DES provides an optimal alternative to conventional organic solvents due to its superior extraction efficiency and sustainability.