Supercritical fluid extraction

Supercritical fluid extraction is an extraction process using fluid above critical temperature and pressure as solvent. The fluid near the critical point not only has extremely high solubility to the substance, but also the solubility of the substance changes with the pressure or temperature of the system. Therefore, selective extraction of the separated substance can be conveniently conducted by adjusting the pressure or temperature of the system.

The application of supercritical fluid extraction in food is a matter of nearly 20 years. Zosel first studied supercritical fluid extraction to remove caffeine from coffee in 1974; In 1978, Hag A.G first established the industrial equipment and technology to remove caffeine from coffee beans, which was an important milestone in the application of supercritical fluid extraction in the food industry. At present, supercritical fluid extraction has been widely used in the extraction and separation of oil, cholesterol, spices and pigments.

Supercritical fluid extraction in food processing almost all use CO2 as extractant. CO2 is not only a strong solvent, it can extract a wide range of compounds in food processing, but also relatively stable, inexpensive, non-toxic, non-combustible and reusable. CO2 production cost low, high purity gas, no residue. CO2 critical point is lower, the critical degree of 31.1 ℃, the critical pressure is 7.38 MPa, so especially suitable for extracting volatile and heat sensitive material. Compared with traditional solvents of n-hexane and dichloromethane, it has obvious advantages. Articles come from the Internet

Supercritical foaming equipment