Supercritical CO2 extraction of squalene from licorice


Through repeated experiments in this experiment, it was found that under the conditions of extraction pressure of 35 MPa and extraction temperature of 40 ℃, squalene was well extracted and separated.


The legume plant Glycyrrhiza is used as a medicine for root and rhizomes.

Supercritical CO2 extraction of licorice
Supercritical CO2 extraction of licorice

It has the functions of nourishing qi and replenishing qi, clearing heat and detoxifying, expectorant and cough, slowing pain and relieving pain.

It is included in the dual-use list of medicine and food published by the Ministry of Health and has good edible And medicinal development value.


Squalene is a kind of lipid unsaponifiable, which has the functions of anti-tumor, suppressing cardiovascular disease and enhancing immunity. It has been widely used in food, health products and other industries. Studies have reported that licorice contains a highly active ingredient Squalene.

Supercritical CO2 extraction of Squalene
Supercritical CO2 extraction of Squalene

Squalene is a polyunsaturated hydrocarbon produced during the metabolism of human body such as cholesterol synthesis. It contains 6 isoprene double bonds and belongs to terpenoids. Squalene is contained in many foods, including shark liver oil. Higher, squalene content is relatively higher in a few vegetable oils such as olive oil and rice bran oil.

Since squalene was discovered by Japanese chemist Dr. Manmanmaru in 1906, it has aroused the interest of researchers at home and abroad due to its good biological activity and wide application in food and cosmetics fields.


In recent years, many studies have pointed out that the intake of squalene has the effect of resisting hypoxia, and many research institutions at home and abroad have published related results.

For example, after mice ingested squalene, the survival time of normal hypoxia and sodium nitrite poisoning was significantly prolonged at different doses; in the case of acute cerebral ischemic hypoxia, squalene was ingested.

It can prolong the breathing time of test animals. While achieving the above-mentioned effects, no toxic side effects of squalene were found.

For example, a study by the Fujian Provincial Center for Disease Control and Prevention also obtained similar results. After 30 days of squalene administration, mice in the medium and high dose group were injected with sodium nitrite.

The survival time and wheezing time were significantly improved under acute and cerebral ischemic hypoxia conditions, respectively. Based on the above results, squalene is also a widely used functional ingredient of hypoxia-resistant health foods in the domestic market.

Promote skin health

Studies have shown that squalene has stronger antioxidant capacity than other lipid molecules in the skin.

Squalene in the skin effectively inhibits the cascade of lipid peroxidation, thereby helping the skin to resist the effects of ultraviolet radiation and other oxidation reactions.

Many studies have pointed out that in addition to antioxidation, squalene (and its derivative squalane) also has emollient and moisturizing effects.

A population experiment examined the relationship between squalene supplementation and skin health: 40 female subjects over 50 years of age were divided into two groups, each taking 90 days for 13.5g and 27g squalene, 37 Volunteers finally completed the test.

The facial wrinkles of the subjects in the high-dose group were significantly reduced, and the facial rash and pigmentation were significantly improved in both groups.

Some of the molecular indicators related to facial skin were also different in the two groups. improve.


Squalene is easily emulsified in cosmetic standard formulations (such as creams, ointments, sunscreens), so it can be used in creams (cold creams, cleansers, moisturizers), lotions, hair oils, hair creams, lipsticks, It is used as a humectant in cosmetics such as aroma oils and powders, as well as an antioxidant and a free radical scavenger.

In addition, squalene can also be used as a high-fat agent for high-grade soaps.

Extraction process

Take the licorice powder into a 1 L extraction kettle, install the equipment, and perform extraction according to the experimental parameters set by the extraction process.

Extract with 200 mL of acetone as the entrainer for 2 h until the extraction kettle has no extraction stream; use 200 mL 95% Ethanol was used as the entrainer, and extraction was continued for 2 h. The extracts were taken twice, and the solvent and entrainer were removed by rotary evaporation. A certain amount of the extract was accurately weighed, and the volume was dissolved in chloroform to determine the volume.

Supercritical fluid extraction conditions

Extraction pressure 35 MPa, extraction temperature 40 ℃, separation temperature ⅠThe temperature is 40 ℃, the temperature of separation Ⅱ is 30 ℃, the flow of CO2 is 30 L / h, the pressure of separation Ⅰ is 8 MPa, and the pressure of separation Ⅱ is 5 MPa.

HPLC analysis conditions

Chromatographic column: ODS2C18 column (4.6 mm × 150 mm × 5 μm); detection wavelength: 210 nm; mobile phase: methanol-acetonitrile (volume ratio 60:40); flow rate: 1.0 mL / min; column temperature: 20 ° C. Under these conditions, the retention time of the squalene standard is17.60 min.

270 g of licorice powder was extracted by supercritical CO 2 -acetone until no product flowed out of the separation kettle to obtain an extract of 5.47 g, of which squalene content was 0.47%; 95% ethanol was further added as an entrainer to obtain an extract of 15. 81 g with a squalene content of 0.14%. After supercritical extraction, the total extraction rate of licorice squalene was 0.018%.

Conditions for Squalene Extraction by Supercritical CO2

Factors affecting supercritical CO2 extraction include extraction temperature, extraction pressure, CO2 flow rate, extraction time, entrainer used, particle size of raw materials, etc. Among them, extraction temperature and extraction pressure are the most important factors.

The reported research on the supercritical fluid extraction process parameters of a variety of traditional Chinese medicines and foods shows that within a certain range, the pressure increases, the solvent density increases, and the dissolving capacity increases; when the temperature is appropriately increased, the molecular activity is enhanced, the mass transfer coefficient, and volatility are increased.

Both the degree and diffusivity are improved, which is beneficial for extraction, but at the same time the density of the supercritical fluid will decrease.

Through repeated experiments in this experiment, it was found that under the conditions of extraction pressure of 35 MPa and extraction temperature of 40 ℃, squalene was well extracted and separated.

Extraction process data

Extraction pressure: 40 MPa

Extraction temperature: 40°C

Entrained solvent: Acetone

Separation temperature Ⅰ: 40°C

Separation pressure Ⅰ: 8 MPa

Separation temperature Ⅱ : 30°C

Separation pressure Ⅱ: 5 MPa

Extraction time: 120 min