Supercritical fluid extraction is a technology that uses supercritical fluid as an extractant to separate one component from another.
Supercritical CO2 fluid can be used to separate and extract specific substances from solid media, and can also be used to separate and purify specific components in liquid media.
Supercritical extraction is usually carried out at a temperature slightly above room temperature, so there is little loss or damage to volatile components or physiologically active substances, and it is particularly suitable for the extraction and separation of natural active substances.
Technical Points Of Supercritical Co2 Extraction Of Curcumin
Curcumin is divided into dedimethoxycurcumin, demethoxycurcumin and curcumin. The main extraction methods can be divided into organic solvent extraction and water extraction. The existing extraction methods are prone to degrading curcumin during the extraction and recovery of solvents, and supercritical CO2 extraction technology, as a new green extraction and separation technology, can effectively extract high-purity curcumin from turmeric.
After the turmeric raw material is crushed and sieved, it is placed in an extraction kettle for extraction. After the extraction is completed, the content of curcumin in the turmeric residue after extraction is detected, and the extraction rate of curcumin is compared with the content of curcumin in the raw material.
Under the condition that other conditions remain unchanged, the influence of different raw material particle sizes on the extraction effect is studied: as the raw material particle size decreases, the efficiency of supercritical carbon dioxide extraction increases. When the particle size is reduced to 0.5mm, the extraction rate no longer increases, but the material will stick together due to the small particle size, thereby increasing the difficulty and cost of crushing. Therefore, the particle size of the raw material should be selected at 1mm.
Curcumin in turmeric is sensitive to heat and light. The supercritical CO2 extraction method has obvious advantages in its extraction and separation. The addition of entrainers improves the extraction efficiency of curcumin.
Advantages of supercritical CO2 extraction compared with traditional solvent extraction methods
- CO2 fluid is safe and non-toxic, suitable for food and pharmaceutical industries.
- Easy to operate, extraction and separation are completed in one time, and there is no solvent residue.
- Non-toxic, high safety, non-toxic, non-explosive.
- Low viscosity and high penetration can effectively penetrate deep into the extract and separate the effective components.
- Low temperature and room temperature extraction have a wide range of application and are not easy to destroy natural functional components. They are suitable for extracts that are sensitive to heat or easily oxidized.
Conclusion
SFE is a typical operation at high solvent feed ratio, high space velocity and low fluid viscosity. It is generally believed that SFE-CO2 can selectively extract plant aromatic oils, esters, alcohols, aldehydes, terpenes, and light fractions in waxes and resins, while leaving heavy fractions, fatty acids, triglycerides, chlorophyll, pigments and other high molecular weight substances in waxes and resins in the extraction phase.
Compared with traditional liquid-liquid extraction, SFE-CO2 has certain advantages in the extraction of certain active substances and has better selectivity. The reliability, safety, rationality of operation and sufficient convenience of supercritical fluid extraction technology make it have broad application prospects in the food, chemical and pharmaceutical industries.