Extraction techniques for valuable oilseeds (grape seeds, walnuts, evening primrose, maple seeds, roses, Eucommia ulmoides seeds, seabuckthorn seeds, etc.)

The use of subcritical low-temperature extraction technology to extract precious heavy oil seed oil has the characteristics of high oil yield, good oil quality, and low cost. Especially suitableValuable oilseeds such as grape seeds, flaxseed, walnut kernels, wheat germ, peony seeds, pumpkin seeds, evening primrose seeds, etc.

subcritical(The main solvents are butane, propane, and their mixtures)Extraction technology is a breakthrough technology in the food processing industry of this century,Has a low boiling point as a solvent, is in a gaseous state at room temperature and pressure, and is easily volatileAfter being pressurized, it becomes liquidThe characteristics.

Subcritical fluids are mainly liquefied butane and propane. The boiling points of most components in this solvent areBelow 0 ℃,The boiling point of propane is -42.07 ℃, and the boiling point of butane isAt -0.5 ℃Subcritical fluid extraction is carried out under sealed and oxygen free conditions, with simple operation, safety, and convenience. The basic principle of this process is: at room temperature and a certain pressure（0.3MPa—0.8MPa）, Using subcritical fluid to leach oil embryos or particles in reverse flow, then reducing the pressure and gasifying the solvent in the mixed oil and meal. The vaporized solvent gas is then compressed, condensed, and liquefied by a compressor before being recycled for use. Part of the heat absorbed during the solvent gasification process comes from the system itself, while the other part is supplied by the heating system.

Subcritical fluids are mainly liquefied butane and propane. The boiling points of most components in this solvent are below 0 ℃, with propane having a boiling point of -42.07 ℃ and butane having a boiling point of -0.5 ℃. It is a gas at room temperature and pressure, and becomes a liquid under pressure.

The basic principle is to extract oilseed embryos (such as grape seeds, walnut kernels, evening primrose seeds, etc.) with subcritical fluid in reverse flow at room temperature and a certain pressure (0.2MPa-0.6MPa), and then reduce the pressure and vaporize the solvent in the mixed oil and meal. The vaporized solvent gas is then compressed, condensed, and liquefied by a compressor before being recycled for use.

This technology has now completely replaced supercritical technology, with low cost (comparable to solvent extraction cost of No. 6, 60% lower than supercritical extraction cost) and large scale (processing 50 kilograms to 50 tons per day). Widely used in the extraction of thermosensitive materials, ensuring that the effective components of the material are not damaged by temperature.

Technical advantages

(1) The quality of the extracted meal is good, with a water soluble protein invariance rate of over 95%, residual oil content of less than 1%, and residual solubility of less than 50ppm;
(2) Low dissolution consumption, with a dissolution rate of less than 6kg per ton of material;
(3) No steam required, only 90 ℃ hot water is needed, which can save 70% of thermal energy compared to solvent No. 6;
(4) There is no "three wastes pollution" in production, which belongs to environmental protection engineering;
(5) The extracted oil has a light color, low lecithin content, and residual solubility in the oil is less than 1ppm;
(6) Room temperature extraction, low-temperature (less than 30 ℃) desolvation, does not damage the thermosensitive substances in meal and oil, making it an ideal process for the quality extraction of valuable oil, pigments, and traditional Chinese medicinal materials;
(7) Subcritical fluids have a wide range of sources and are priced lower than solvent No. 6.

fit:Microbial oil (ARA/DHA), evening primrose seed oil, borage oil, fennel oil, star anise oil, ginger oil, garlic oil, onion oil, Sichuan pepper oil, cinnamon oil, pepper oil, safflower seed oil, rosehip oil, pomegranate seed oil, wisteria seed oil, wenguan fruit oil, maple oil, Moringa seed oil, passion fruit seed oil, cocoa, seabuckthorn seed, etc.

Based on years of user production experience, we will take the process of low-temperature extraction of grape seed oil as an example.

Processing technology of grape seed oil

Preprocessing technology

The raw materials are sieved by a vibrating screen to remove impurities such as skin residue and fruit residue from grape seeds. Then, they are transported by a conveyor and put into a softening pot. A certain amount of water is added, and the temperature is raised to 45-55 ℃ and kept for a certain period of time (about 15 minutes) for softening. After iron removal, they are put into a rolling mill for rolling, with a thickness of 0 3 mm， The moisture content is kept at around 8%, and the raw pieces are sent to the extraction workshop.

Extraction process flow

1. Put grape seed slices into the extraction tank.

2. The solvent pump injects solvent No. 4 into the leaching tank to soak the green pellets.

3. The solvent pump extracts the mixed oil from the leaching tank and pumps it into the evaporation tank.

4. Connect the leaching tank with the suction port of the compressor, allowing the residual solution in the meal to vaporize and enter the compressor. After compression and condensation in the condenser, the solvent is liquefied and refluxed to the solvent tank for recycling. Grape seed meal is discharged from the leaching system.

5. The mixed oil enters the evaporation system to separate the solvent from the crude oil after evaporation. The solvent vapor is compressed and liquefied before being recycled for use. Grape seed oil discharge evaporation system.

6.Crude oil purification crude oilThe oil filter adopts low-temperature filtration, cooling down to15~20℃Minimize the loss of aroma volatilization to the greatest extent possible. Adopting a new process of filtration, settling, and filtering. Fully filter out non hydrophilic phospholipids to minimize the phospholipid content in the oil, in order to improve the stability of the storage period.