Sub-critical low temperature extraction technology

Sub-critical low temperature extraction technology is to use sub-critical fluid as extraction agent in a closed, oxygen-free, low-pressure pressure vessel, based on the principle of similar phase dissolution of organic matter, through the molecular diffusion process of extraction materials and extraction agent in the process of immersion.  The fat soluble components in solid materials are transferred to liquid extractant, and then the extractant and the target product are separated through the process of vacuum evaporation, and finally a new extraction and separation technology of the target product is obtained.  Compared with other separation methods, sub-critical fluid extraction has many advantages: non-toxic, harmless, environmental protection, no pollution, non-thermal processing, retention of the active ingredient of the extract does not damage, does not oxidize, large capacity, large-scale industrial production, energy saving, low operating cost, and easy to separate from the product.  
 
 

Principle and flow chart of sub-critical low temperature extraction technology

Sub-critical fluid extraction technology is to use the special properties of the above sub-critical fluid, the material is injected into the sub-critical fluid soak in the extraction tank, under a certain material solubility ratio, extraction temperature, extraction time, extraction pressure, extraction agent and en-trainer, stirring, ultrasonic assisted extraction process.  After solid-liquid separation, the extraction mixture enters the evaporation system. Under the action of compressor and vacuum pump, the extraction agent is converted from liquid to gas according to the principle of vacuum evaporation, so as to obtain the target extract.  

Sub-critical fluid extraction has many advantages compared with other separation methods:

Compared with other separation methods, sub-critical fluid extraction has many advantages: non-toxic, harmless, environmental protection, no pollution, non-thermal processing, retaining the active ingredient of the extract does not damage, does not oxidized, large capacity, can be industrialized large-scale production, energy saving, low operating cost, and easy to separate from the product.  

Application of sub-critical cryogenic extraction technology

Application in extraction of natural products  
Because the sub-critical fluid is a gas state at room temperature and pressure, it is easy to vaporize, so it can be used to extract and separate heat-sensitive materials at room temperature or lower temperature.  After practice, subcritical fluid extraction technology has been applied in the extraction of lipid soluble components of many natural products.  Such as koelreuteria paniculata seeds, seedless fruit, green thorn fruit, sea buckthorn, pistacia fruit, tiger nuts, rose, lavender, gingko leaves, artemisia annua and so on.  
Application in food industry  
Sub-critical fluid extraction technology applied in food industry, mainly concentrated in the consumption of plant powder skim link and byproduct oil applications, due to certain plant fruit itself is rich in oil and food with high oil rancidity extremely easily, shelf life is short, therefore, degreasing powder plants become a key link in the process of plant powder production.  Dozens of materials such as soybean, peanut, walnut, almond, wheat germ, coffee bean and pumpkin seed were removed by sub-critical fluid extraction technology, and corresponding vegetable oil was extracted at the same time.  From the point of view of extraction effect, the active components of plant powder obtained at low temperature were protected to the maximum extent. Taking plant protein as an example, the NSI of water-soluble protein was above 86%, and the VE component of wheat germ oil was above 95%.  Compared with other methods, it has obvious advantages: the amount of processed material is generally 30-100 tons/day, and the extraction time is short and the cost is low.  With the development of natural products, sub-critical fluid extraction technology has a broader application prospect in food industry.  
In addition, the sub-critical fluid has a good effect on the extraction of cream from whole milk powder, the extraction rate is more than 20%, the extracted cream taste is pure, it is the best production process for milk powder (including expired milk powder) to extract cream.  
Application in traditional Chinese medicine (including compound Chinese medicine) industry  
The application of sub-critical fluid extraction in traditional Chinese medicine industry has involved the extraction of effective components of traditional Chinese medicine and compound Traditional Chinese medicine, and has realized industrial production.  For example, the critical extraction from schisandra chinensis, safflower, ligusticum chuanxiong, Ganoderma lucidum spore, silythistle, Trichosanthes kirilothes, Angelica sinensis, acanthopanax acanthopanax is superior to petroleum ether extraction, larger than supercritical daily treatment capacity, with high yield, short extraction cycle and no solvent residue, especially suitable for the extraction of lipid-soluble active components of Traditional Chinese medicine.  
In addition, due to the side effects of many fat-soluble components in traditional Chinese medicine (TCM), subcritical fluid extraction (SUBcritical fluid extraction) has a great development space for degreasing before TCM processing.  
Application in the extraction of animal fat  
In terms of the extraction of animal oil, it has been achieved to extract frog egg oil from wood frog egg, yellow mealworm oil from yellow mealworm oil, silkworm pupa oil from silkworm pupa oil, scorpion oil from scorpion oil, sheep hooves oil from sheep.  
Application in natural pigment industry  
Subcritical fluid extraction technology has made great progress in the extraction of pigments. In Hebei, Shandong, Yunnan, Xinjiang, Gansu and Jilin, more than ten subcritical fluid extraction production lines have been established, mainly engaged in the production of capsicum red pigment, marigold yellow pigment, tomato red pigment, curcumin and silkworm green pigment.  
Application in natural fragrance industry  
In the natural fragrance industry, has been extracted rose extract, ten coriander extract, mint extract, osmanthus extract, jasmine extract, cocoa butter and other products.  
Application in special grease  
In the production of special oil, it has involved dozens of special oil such as wheat germ oil, grape seed oil, almond oil, pumpkin seed oil, flaxseed oil, pomegranate seed oil, orange seed oil, cherry seed oil, sea-buckthorn oil, Prickly ash oil, sunflower seed oil, flax oil, green thorn kernel oil, pine nut oil, garlic oil, onion oil, ginger oil and so on.