Table 1.
Extraction technologies and analytical techniques used to obtain and characterize polyphenol compounds from pomegranate peel.
| Technology | Extraction Conditions |
Identification Method | Outcome | Ref. |
|---|---|---|---|---|
| SL | Diethyl ether; 80% methanol; water 1 h Room temperature |
Not indicated | DE: 6.2 mg GAE/g MW: 262.5 mg GAE/g W: 82.5 mg GAE/g |
[26] |
| SL | Water/ethanol 1:1 Room temperature 24–48 h |
RP-HPLC | Identification of punicalagin A and B, ellagic acid | [28] |
| USE | Acetone (70%) 20 min at 30 °C |
HPLC-DAD-ESI-MS | Identification of seventy-nine phenolic compounds | [32] |
| SL | Water 60 °C for 30 min |
RP/HPLC/ESI/ MS |
Hydrolyzable tannins: 532.98 mg g−1 Condensed tannins: 471.81 mg g−1 |
[33] |
| SL USE IR |
Deep eutectic solvents 50 °C for 90 min |
HPLC | SL: 13 mg/g DM US: 114 mg/g DM IR: 152 mg/g DM |
[34] |
| MAE USE |
MAE: 50% aqueous ethanol LSR: 60:1 mL/g 600 W for 4 min UAE: water LSR: 32.2:1 mL/g Amplitude level: 39.8% Pulse: 1.2/1 at 34.7 °C for 10 min |
HPLC-UV–vis | Punicalagin MAE: 143.64 mg/g DM USE: 138.8 mg/g DM |
[35] |
| PLE | Ethanol (77%) 200 °C Pressure 1500 psi for 20 min |
HPLC-DAD-ESI-TOF/MS | TPC: 164.3 ± 10.7 mg GAE/g DM Punicalagin: 17 ± 3.6 mg/g DM |
[36] |
| EASEEASCFE | CK: cellulase, pectinase, and protease; (50:25:25) at 3.8%, 49 °C pH 6.7 for 85 min |
HPLC-DAD-ESI–MS | TPC: 301.53 mg GAE/g Identification of gallic, caffeic, p-coumaric, ferulic, syringic, sinapic, and vanillic acids |
[37] |
Abbreviations: SL: solid-liquid extraction, USE: ultrasound-assisted extraction, IR: infrared extraction, MAE: microwave-assisted extraction, PLE: pressurized liquid extraction, EASE: enzyme-assisted solvent extraction, EASCFE: enzyme-assisted supercritical fluid extraction, CK: cocktail enzyme, DM: diethyl ether, MW: water/methanol, W: water, TPC: total polyphenol content, GAE: mg of gallic acid equivalent, DM: dry matter.