Table 3.
Subcritical water extraction of organic acids.
| Samples | Medicinal Parts | Compounds Extracted | Extracts Activity | Extraction Conditions | Analytical Methods | Other Extraction Methods (Solvent, Ratios of Yields) | Ref. |
|---|---|---|---|---|---|---|---|
| Panax ginseng Meyer | root | TP, chlorogenic acid, caffeic acid, gallic acid, etc. | antioxidant (DPPH, ABTS, FRAP, HRS) | 100–240 °C, 15 min, 4–9 MPa, 200 rpm |
HPLC, UV | [23] | |
| Helicteres isora L. | hexadecanoic acid, octadecnoic acid, heptadecen-8-carbonic acid etc. | antibiofilm, antioxidant, antimicrobial, antienzymatic |
160 °C, 30 min, 1 MPa, 1: 30 g/mL | GC-MS, UV | [27] | ||
| XiLan olive fruit | olive dreg | TP, chlorogenic acid, gallic acid, syringic acid, etc. | antioxidant (ABTS, DPPH, reducing power) | 100–180 °C, 5–60 min, 1:20–1:60 g/mL | LC-MS-IT-TOF, UV | convention (methanol 3.2%; ethanol 0.6%; DMK 0.9%) | [33] |
| Camellia oleifera Abel. | seeds | free fatty acids (palmitic acid, stearate, oleic acid, etc.), tea saponin | antioxidant (DPPH) | 60–160 °C,2–7 MPa, 5–60 min, 1:3–1:25 g/mL |
GC-MS, FT-IR | Soxhlet (petroleum ether 100%), cold pressed (100%) | [37] |
| sunflower seeds (Natura) | dehulled seeds | total proteins, total carbohydrates, TP | antioxidant capacities | 60–160 °C, 5–120 min, 3 MPa, 1:10–1:30 g/mL |
GC-FID, UV-Vis, HPLC | Soxhlet (hexane 67.3%) | [38] |
| cottonseed (Egypt) | cottonseed | linoleic acid, palmatic acid, oleic acid, myristic acid | 180–280 °C, 5–60 min, 1:2–2:1 g/mL | GC-FID, | heating (hexane 89.5%) | [39] | |
| green coffee (Robusta Uganda) | beans | chlorogenic acid | 130–170 °C, 40–90 min, 0–30 % ethanol | HPLC | convention (ethanol 66.7%) | [45] | |
| Nannochloropsis gaditana | fatty acids, omega-3, omega-6, lipid | 156.1–273.9 °C, 6.6–23.4 min, 33–117 g/L | GC-FID, SEM | Soxhlet (n-hexane 100%) |
[51] | ||
| Saccharina japonica | gallic, caffeic, vanillic, syringic, chlorogenic, p-hydroxybenzoic acids, etc. | antioxidant (DPPH, ABTS, total antioxidant (FRAP) | 100–250 °C, 5 min, 5 MPa, 0.25–1.00 M ILs | HPLC, UV | convention (DMK 0.2%; DCM 0.3%; Et2O 0.8%; IL 1.6%) | [52] | |
| Haematococcus pluvialis | p-hydroxybenzoic acid, gallic acid, siringic acid, vanillic acid, etc. | antioxidant (ABTS, TEAC), antimicrobial activity | 50–200 °C, 20 min, 10 MPa |
HPLC-DAD-MS, SEM, GC-MS | [53] | ||
|
Momordica charantia
|
fruits | TP, gallic acid, gentisic acid, chlorogenic acid | antioxidant (ABTS) | 130–200 °C, 10 MPa, 2–5 mL/min | HPLC, UV | Soxhlet (methanol 4.9%), UAE (methanol 4.0%) | [132] |
| Morus nigra L., Teucrium chamaedrys L., Geranium macrorrhizum L., Symphytum officinale L. | leaves, flowers | TP, chlorogenic acid, gallic acid, vanillic acid, etc. | antioxidant, antifungal, antibacterial, cytotoxic | 60–200 °C, 30 min, 1 MPa, 1:40g/mL | HPLC-DADUV | [133] | |
| Prunus avium L., Prunus cerasus L. | stems | 3 alcohols, 10 organic acids, etc. | antioxidant, antiproliferative | 150 °C, 30 min, 2 MPa | GC-MS, UV | [134] | |
| Castanea sativa | nuts | ellagic acid, feru lic acid, gallic acid, etc. | antioxidant | 120–135 °C, 15–60 min |
HPLC | [135] | |
| Solanum tuberosum | potato peel | TP, gallic acid, caffeic acid, chlorogenic acid, protocatechuic acid, etc. | 100–240 °C, 30–120 min, 6 MPa |
HPLC, UV | convention (methanol 1.6%; ethanol 2.0%) | [136] | |
| Actinidia deliciosa | pomace | TP, chlorogenic acid, protocatechuic acid, etc. | antioxidant (DPPH, FRAP, ABTS) | 170–225 °C 10–180 min, 5 MPa |
UV, HPLC, pH | [137] | |
| hypnea musciformis | chlorogenic, protocatechuic, and gallic acids, TP, TF, etc. | antioxidant (DPPH, ABTS), emulsify | 120–270 °C, 10 min, 1:50–1:150 g/mL |
pH, UV, HPLC | [138] | ||
| Carica papaya L. | papaya seeds |
TP, 18 phenolic acids, 20 flavonoids, 1 stilbene, etc. | antioxidant (DPPH, β-carotene bleaching) | 70–150 °C, 10 MPa, 1–40 min, 4 mL/min | LC-ESI-MS/MS, UV | Soxhlet (water 37.1%) | [139] |
| Zingiber officinale | ginger rhizome |
12 sugars, 8 diols, 4 phenolic acids, etc. | antimicrobial, cytotoxic | 150 °C, 1 h, 1:10 g/mL | HPLC-ESI-TOFMS | heating (water) | [140] |
| Chlorella sp. microalgae | TP, caffeic acid, ferulic acid, p-coumaric acid | antioxidant (DPPH) | 100–250 °C, 5–20 min |
UV, SEM, HPLC | [141] | ||
| Vitis vinifera | vine-canes | TP, flavonoids, phenolic acids, flavonols | antioxidant, antiradical | 125–250 °C, 50 min | HPLC, UV | [142] | |
| Cinnamomum Cassia Blume | cinnamon | coumarin, cinnamic acid, cinnamaldehyde, cinnamyl alcohol, etc. | 110–130°C, 20–60 min, 2–4 MPa, 1:10 g/mL | HPLC | [143] |