Supercritical CO2 extraction equipment is a kind of equipment used in the fields of food, medicine and chemical industry. Supercritical CO2 fluid extraction technology is a new separation technology in modern chemical separation, which has the characteristics of fast mass transfer rate, strong penetration ability, high extraction efficiency and low operating temperature.
The oil obtained by supercritical CO2 fluid extraction process generally has an oil yield of more than 95%, low impurity content, light color, and can save refining processes such as vacuum distillation and deodorization. Compared with traditional methods, the residue after oil extraction remains intact and can be conveniently used to extract protein, mix with food or use as feed.
The application of supercritical CO2 fluid extraction technology to plant oils is relatively wide and mature. At present, it is widely used in the development of various oil products, such as rice bran oil, soybean oil, peanut oil, sunflower oil, corn germ oil, wheat germ oil, sea buckthorn oil, etc., and good industrial application results have been achieved.
Method for refining wheat germ oil by supercritical CO2 fluid extraction
Process flow: wheat germ → pretreatment → supercritical CO2 fluid extraction → two-stage separation → refined wheat germ oil.
This method uses two separation kettles to reduce the pressure and change the temperature step by step. Wheat germ oil can be precipitated from CO2 step by step according to its properties. The process of producing wheat germ oil can further omit the deacidification and deodorization refining steps on the basis of using supercritical CO2 fluid extraction technology to omit the decolorization and degumming refining steps, that is, directly obtain commercial wheat germ oil.
This method gives full play to the advantages of supercritical CO2 fluid extraction technology that the process operation can be flexibly adjusted according to the target product, solves the problem that wheat germ oil has high acid value and odor due to containing more free fatty acids, and can also obtain high-quality defatted germ while producing high-quality wheat germ oil.
The defatted germ becomes easy to preserve because the oil and part of the water are removed. It can be eaten directly or used as a raw material for producing high-protein food, meeting the requirements of the low-fat group.
Supercritical CO2 fluid extraction was used for one-stage separation and two-stage separation, respectively. The acid value was reduced from 7.89 mg KOH/g oil in the first-stage separation to 1.00 ng KOH/g oil in the two-stage separation, and the quality of the oil was significantly improved.
Conclusion
Supercritical CO2 extractor can obtain useful components to the maximum extent, and can selectively extract and separate. It is suitable for the extraction and separation of effective components such as volatile oils, fatty oils, coumarins, terpenes, alkaloids, quinones, etc.