Related Experiment Video
Updated: Jun 18, 2026
Employing Pressurized Hot Water Extraction PHWE to Explore Natural Products Chemistry in the Undergraduate Laboratory
Published on: November 7, 2018
The effects of experimental conditions on extraction of polyphenols from African Nutmeg peels using NADESs-UAE: a
Udodinma Jude Okeke1,2,3, Matteo Micucci4, Dasha Mihaylova3
1Department of Pure and Applied Science, University of Urbino Carlo Bo, Urbino, Italy.
Abstract:
Extraction of polyphenolic compounds from African nutmeg (Monodora myristica (Gaertn.)) peels using natural acidic deep eutectic solvents coupled to ultrasound-assisted extraction (NADESs-UAE) followed many factors at a time (MFAT) screening with response surface optimization was investigated. Fourteen different NADESs based on citric acid as hydrogen bond acceptor (HBA) were designed and tested. Sucrose, fructose, xylitol, glycerol, glycine, and glucose were used as hydrogen bond donors (HBDs). The responses studied are total phenolic compounds (TPC), total flavonoid compounds (TFC), and antioxidant activity (AA) based on cupric ion reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP). The UAE procedure was optimized with the most efficient NADES. Quadratic models produced satisfactory fitting of the experimental data regarding TPC (R2 = 0.9999, p < 0.0001), TFC (R2 = 0.9991, p < 0.0001), and AA- CUPRAC (R2 = 0.9988, p < 0.0001) and FRAP (R2 = 1.000, P < 0001). Ultrasound temperature 30°c, extraction time 5 min, solvent volume 25 ml, and solvent concentration 90% (v/v) were considered optimal conditions for the extraction models resulting in TPC 1290.9 ± 5.6 mg/g GAE db, TFC 2398.7 ± 23 µg/g QE db, CUPRAC 38.46 ± 0.4.4 µmol/g TE db, and FRAP 26.15 ± 0.11µmol/g TE db, respectively.
