Method | Solvent | Temperature | Pressure | Time | Volume of Organic Solvent Consumed | Polarity of Natural Products Extracted |
---|---|---|---|---|---|---|
Soxhlet extraction [16, 17] | Methanol, ethanol, or mixture of alcohol and water | Under heat depending on solvent used | Atmospheric | Long | Moderate | Dependent on extracting solvent |
Maceration [17-19] | Methanol, ethanol, or mixture of alcohol and water | Room temperature | Atmospheric | Long | Large | Dependent on extracting solvent |
Percolation [20, 21] | Water, aqueous and non-aqueous solvents | Room temperature, occasionally under heat | Atmospheric | Long | Large | Dependent on extracting solvent |
Decoction [22-26] | Water | Under heat | Atmospheric | Moderate | None | Polar compounds |
Infusion [19, 26, 27] | Water | Under heat | Atmospheric | Short | Moderate | Polar compounds |
Ultrasound-assisted extraction [28-32] |
Methanol, ethanol, or mixture of alcohol and water | Room temperature, occasionally Under heat | Atmospheric | Short | Moderate | Dependent on extracting solvent |
Pressurized liquid extraction [33-35] | Water, aqueous and non-aqueous solvents | Under heat | High | Short | Small | Dependent on extracting solvent |
Reflux extraction [26, 36] | Aqueous and non-aqueous solvents | Under heat | Atmospheric | Moderate | Moderate | Water, aqueous and non-aqueous solvents |
Supercritical fluid extraction [37-40] | Supercritical fluid (usually S-CO2), sometimes with modifier | Near room temperature | High | Short | None or small | Nonpolar to moderate polar compounds |
Subcritical water extraction [41-45] | Water | Under heat | High | Moderate | Small | Nonpolar to moderate polar compounds |
Microwave assisted extraction [32, 46, 47] | Water, aqueous and non-aqueous solvents | Room temperature, occasionally under heat | Atmospheric | Short | None or moderate | Water, aqueous and non-aqueous solvents |
Enzyme assisted extraction [32, 48-51] | Water, aqueous and non-aqueous solvents | Room temperature, or heated after enzyme treatment | Atmospheric | Moderate | Moderate | Water, aqueous and non-aqueous solvents |
Hydro distillation and steam distillation [52, 53] | Water | Room temperature | Atmospheric | Long | None | Essential oil (usually non-polar) |