Supercritical fluid technology is a new separation technology in modern chemical separation. Supercritical extraction uses CO2 as solvent, because CO2 fluid in supercritical state has greater density and dielectric constant, greater solubility for substances, and its solubility changes suddenly when temperature and temperature change. Therefore, it is not only selective for the solubility of certain substances, but also easy to separate solvents and extracts.
With the increasing maturity of supercritical fluid extraction technology and the deepening of basic research on natural medicines, the application of this technology in the fields of medicine, food, and chemical industry has attracted much attention and has broad application prospects.
Seven Advantages And Characteristics Of Supercritical Co2 Extraction Process
- Feature 1#: Extraction under low temperature conditions. Supercritical CO₂ extraction process is carried out at a lower temperature (35~40℃) and CO₂ gas environment, which can effectively prevent the oxidation and escape of heat-sensitive components, and can better protect the effective components of Chinese herbal medicines and various oils from being destroyed. Therefore, it is suitable for the extraction of moisture-, heat-, and light-sensitive substances and components that are easily oxidized and decomposed.
- Feature #2: Clean extraction method. CO₂ is an inactive gas that is tasteless, odorless, and non-toxic. Therefore, there is no residual solvent in the extract, and it also prevents the poisoning of the human body and the pollution of the environment during the extraction process. Supercritical CO₂ also has antioxidant and sterilization effects, which is conducive to ensuring and improving the quality of the product.
- Feature #3: Strong extraction ability and high extraction rate. Supercritical CO₂ fluid has strong solubility and permeability, fast diffusion rate, and is carried out under continuous flow conditions. The extraction product is constantly removed, and almost all the components required for extraction can be extracted, thereby improving the product yield and resource utilization.
- Feature #4: The extraction process is simple, time-saving, and production efficiency is high. Supercritical CO₂ extraction combines extraction and separation into one. At the beginning of the supercritical CO₂ extraction cycle, separation also begins. Generally, the components are separated and precipitated after 10 minutes of extraction, and they can be completely extracted in 2~4 hours. At the same time, it does not require steps such as concentration, and even if entrainers are added, they can be removed through the separation function.
- Feature #5: Selective extraction and separation can be performed. The density, viscosity, solvation ability, diffusion coefficient and other properties of supercritical CO₂ fluid vary greatly with temperature and pressure. Therefore, it is very sensitive to selective separation and can be achieved by changing the temperature and pressure of the system.
- Feature #6: It can be combined with modern analytical technology. Supercritical CO₂ extraction technology can be combined with modern analytical technologies such as gas chromatography, high performance liquid chromatography, thin layer chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, etc., so that component analysis can be performed more efficiently and quickly, and the content of effective ingredients in traditional Chinese medicine can be objectively reflected.
- Feature #7: The residue can be comprehensively utilized. The residue extracted with pure CO₂ can also be well comprehensively utilized to give full play to the comprehensive benefits. For example, corn flour after extracting corn oil, wheat germ after extracting wheat germ oil, and ginger powder after extracting ginger oil can all be used as good functional foods or feeds.
Conclusion
Supercritical CO₂ extraction technology is widely used in the extraction of active ingredients of traditional Chinese medicines such as volatile oils, flavonoids, alkaloids, saponins, polysaccharides and quinones. Its application in the extraction and refining of traditional Chinese medicines helps to improve the quality and efficacy of traditional Chinese medicine products.