Table 2.
Different methods used for the extraction of polyphenols from grape pomace.
| Extraction Method | Raw Material | Main Compounds Identified | Phenolic Content | Reference |
|---|---|---|---|---|
| UAE (Ethanol, 25 kHz, 20 °C, 60 min) | Agiorgitiko red GP | Delphinidin, Malvidin-3-O-glucoside, Myricetin, Quercetin | TPC: 438,984 ± 4034 ppm GAE | Drosou et al., 2015 [133] |
| UAE (Temperature: 80 °C, Time: 4 min) and SFE | Red GP | Proanthocyanidins | TPC: 3493 ± 61 mg GAE/100 g DW | Da Porto et al., 2015 [129] |
| UAE (Frequency: 2458 MHz, Power Density: 1000 W/L, Time: 30 min, Temperature: 28 ± 3 °C) | Red skin GP | Malvidin-3-O-glucoside, Quercetin, Catechin, Myricetin | TPC: 104 mg GAE/g | Caldas et al., 2018 [134] |
| MAE (Time: 10 min, Power: 93 W, Temperature: 24 ± 1 °C) | Chardonnay GP | Flavanols, Quercetin, Kaempferol, Gallic acid | TPC: 1.21 ± 0.04 mg GAE/mL | Garrido et al., 2019 [62] |
| Subcritical Water Extraction (SWE) (Time: 10 min, Pressure: 10.34 MPa) and NaDES | Red GP | Catechin, Epicatechin, Procyanidins, Resveratrol | Catechin and epicatechin: 45.05% and 47.98% increase | Loarce et al., 2020 [44] |
| SLE (Ethanol, Ethanol –Water, Water) | White GP (whole, skins, seeds, stems) | Gallic acid, Catechin, Quercetin-3-O-glucoside, Kaempferol-3-O-glucoside | TPC: 2797.67–9839.86 mg GAE/100 g | Jara-Palacios et al., 2020 [78] |
| SWE (Temperature: 100–200 °C, Pressure: 25 × 105 Pa) | GP (red and white varieties) | Gallic acid, Procyanidins, Malvidin-3-O-glucoside | TPC: 11.67 ± 1.67–72.52 ± 2.43 mg/g DW | Yammine et al., 2020 [135] |
| NaDES and PHWE | Tempranillo GP | Anthocyanins | Total Anthocyanin Content: 19.62–214.57 mg malvidin-3-O-glucoside eq./L | Loarce et al., 2021 [56] |
| UAE (Temperature: 80 °C, Time: 30 min) and β-CD | Muscat GP | Gallic acid, Catechin, Quercetin | TPC: 57.47 mg GAE/g DW | Alibante et al., 2021 [128] |
| SLE (Ethanol–Water (40/60); 16 h; In Dark) | Negramaro and Fiano whole GP and GP skins | Gallic acid, Caffeic acid, Catechin, Quercetin-3-O-glucoside, Anthocyanins | TPC: 36.8 ± 5.03–127.87 ± 8.03 mg GAE/g DW | Gerardi et al., 2021 [46] |
| MHG (Power: 400 W, Temperature: Approx. 80 °C, Time: Less Than 10 min) | Merlot and Cabernet Sauvignon GP | Gallic acid, Syringic acid, Quercetin | TPC: 118.1 mg GAE/g DW | Moro et al., 2021 [100] |
| NaDES and MAE | White GP | Gallic acid, p-Coumaric acid, Ferulic acid, Quercetin | TPC: 5.94 ± 0.29–43.73 ± 2.19 mg GAE/g DW | Cañadas et al., 2023 [125] |
| SLE (Ethanol–Water (1:1), Sonication: 20 min, Stirring: 2 h) with SPE | White and red GP | Catechin, Gallic acid, t-Caftaric acid, Quercetin, Kaempferol | TPC: 144–298 mg GAE/g DW (skins) and 327–540 mg GAE/g DW (seeds) | Guaita et al., 2023 [47] |
| NaDES and ASE (10 MPa, 90 °C) |
Carménère red GP | Gallic acid, Caffeic acid, Quercetin | TPC: 33.39 ± 0.59–62.44 ± 1.67 mg GAE/g DW | Huamán-Castilla et al., 2023 [50] |
| SLE (Ethanol, HCl) | Touriga Nacional and Sousão GP | 3-O-Caffeoylquinic acid, Quercetin-3-O-glucoside, Malvidin-3-O-glucoside | TPC: 44.93 mg GAE/g | Moutinho et al., 2023 [7] |
| UAE (Temperature: 20 °C, Time: 30 min) and MHG (Temperature: 80 °C, Time: 10 min, Power Density: 2 W/g) with SPE | Aglianico red GP | Catechin, Malvidin-3-O-glucoside chloride, Cyanidin chloride | TPC: 6.5 to 8.5 times higher in MHG | Crescente et al., 2023 [101] |