Supercritical CO2 extraction machine for separating garlic oil and nervonic acid
The single-factor test method was used to investigate the impact trends of the crushing particle size, extraction time, and extraction pressure of the raw materials in the supercritical CO2 extraction process. The optimal extraction process was screened by orthogonal experiments, and the best process garlic extract was GC-MS. The fatty acid composition of the oil was analyzed; the method of saponification and crystallization was used to separate the neural acids.
Supercritical co2 extraction process
Pulverization degree:8 mesh
Extraction pressure: 35 MPa
Extraction temperature: 45°C
Separation kettle Ⅰ pressure: 6 MPa
Separation kettle Ⅰ temperature: 55°C
Extraction time: 120 min
A more suitable extraction process was determined: the crushed particle size of the raw material was 8 meshes, the extraction pressure was 35 MPa, and the extraction temperature was 45 ° C; the pressure in the separation tank was 6 MPa, the analysis temperature was 55 ° C, and the extraction time was 2 hours; the yield of garlic oil was 32.3%, and the acid The content was 5.4%; the fatty acids in garlic oil were analyzed, and 12 kinds of fatty acid components were identified; the yield of neural acid isolated from the oil was 4.6%, and the purity of the neural acid was 96%. Conclusion: Supercritical CO2 extraction of garlic oil and neural acid separation process is stable and feasible, with good reproducibility, and can effectively enrich neural acid.
Malania oleifera Chun et Lee, also known as mangosteen fruit, Malanque (Zhuang language), is a genus of the genus Garlicaceae, is a unique species of China, and the existing resources of the garlic fruit population are very small, only natural. Distributed in a narrow area from western Guangxi to southeast Yunnan. The seeds of garlic seeds are rich in oil and have an oil content of up to 64.5%. They are an ideal raw material for the synthesis of muscone. Studies have shown that the oil contains more than 60% of neuroacids, which is the plant with the highest content of neuroacids in nature.
Neural acid is a long-chain unsaturated fatty acid, which has a significant effect on the treatment of cardiovascular and human autoimmune diseases. It is also an important raw material for spices. The market demand is huge, but it is scarce in nature and difficult to synthesize. Therefore, it is of great significance to realize the industrial production of neural acid with garlic oil as raw material.
In the past, the extraction of garlic oil was mainly based on the squeeze method, and there have been no reports in the world about supercritical CO2 extraction of garlic oil.
Supercritical CO2 extraction technology has been developed for nearly two decades, and it is a high-tech extraction and separation technology. It has the advantages of easy operation and no environmental pollution. In this study, supercritical CO2 method was used to extract garlic oil and single factor method was used to discuss the extraction conditions On the effect of extraction, orthogonal test method was used to optimize the extraction process conditions, and GC-MS method was used to analyze the fatty acid composition in garlic oil of the best process, and the saponification and crystallization method were used to separate the neural acid.
Supercritical CO2 extraction of garlic fruits After crushing garlic fruits and putting them into the extraction kettle, set the temperature and pressure of the extraction kettle and the separation kettle, and then heat the extraction kettle, the separation kettle I, and the separation kettle II separately, and cool them. The mechanism is cold; when the temperature reaches the set value, open the CO2 gas cylinder to increase the pressure; when the pressure required for the experiment is reached, close the CO2 gas cylinder and start the cycle extraction, maintaining the constant temperature and pressure. After the selected time, the separation kettle I The material is discharged from the material outlet, and the golden yellow liquid is mixed to obtain garlic oil. Weigh and calculate the yield.
Isolation of Neural Acid
Take the garlic fruit oil, add an appropriate amount of NaOH-ethanol solution for saponification, remove part of the ethanol, heat the water to make up the volume, acidify to the required pH value, wash the precipitate to neutrality, and dry to obtain the crude fatty acid. Take the crude fatty acid, add an appropriate amount of acetone to remove impurities, recrystallize the residue with ethanol twice, crystal dry, weigh, calculate the yield, and check the purity.
Research on Raw Material Crushing
Take the garlic fruit, remove the shell, crush the flesh, set it in a universal grinder for 10 seconds, and grind the ground material to stick on the wall of the grinder. Garlic pulp has high oil and moisture content, and it is difficult to directly crush it. When crushing, it is generally necessary to string oil with other oil-free or low-oil content materials.
The garlic fruit is crushed with a shell, crushed with a shell, and crushed with a universal grinder. The result: the crushed material is granulated, and the particle size is 0.5 to 1 cm. Better than crushing the flesh alone.
Take the garlic fruit, crush it with a shell, freeze it in a refrigerator at -20 ° C, and crush it in a freeze grinder. Results: The crushed material is granulated with a particle size of 0.3cm or less, which is more uniform, has better dispersibility, and has better effect than ordinary crushing .
Comparison of different crushing methods
Approximately 200 g of the raw materials obtained by the different crushing methods were weighed and placed in a supercritical extraction kettle. The extraction pressure was set to 35 MPa, the extraction temperature was 45 ° C, the separation pressure was 6 MPa, the separation temperature was 50 ° C, and the extraction was circulated for 2 hours.
The dispersibility of garlic and starch oil after crushing is better. When the equipment is intact, the extraction of fruit oil can be completed. However, in addition to a large amount of oil and water, garlic pulp also contains a large amount of starch. Starch is dissolved in the oil to form a paste, which affects the quality of the oil. Freezing and pulverizing can also fully extract garlic oil, and the quality of the oil is better.
Granularity of raw materials
Take garlic fruits, crush them through 8, 14 and 20 mesh sieves, and put the sieved materials into supercritical extraction kettle, set the extraction pressure 30MPa, extraction temperature 45 ℃, separation pressure 6MPa, separation temperature 50 ℃, cycle Extract for 2 hours.
The crushed particle size of 8 mesh is better, the residue is white, and the oil is transparent and golden; when the crushed particle size is 14 mesh, although the extraction is complete and the residue is white, there is a small amount of precipitation in the oil, which affects the quality.
Take garlic fruit and crush it into coarse powder (8 mesh), set the extraction pressure 25MPa, extraction temperature 45 ℃, separation kettle I pressure 6MPa, temperature 50 ℃, separation kettle II pressure 6MPa, temperature 45 ℃. Free neuroacid content is used as an indicator. Observe the trends of extraction at 1, 2 and 3 hours. Under the same conditions, both oil yield and free neuroacid content increase with the extension of supercritical CO2 cycle extraction time. The increase in extraction for 1 hour was significant, but the increase in circulation extraction for more than 2 hours was slow and not significant.
Take the garlic fruit and crush it into 8 mesh coarse powder, set the extraction time for 2 hours, the extraction temperature is 45 ℃, the pressure of the separation kettle I is 6MPa, the temperature is 50 ℃, the pressure of the separation kettle II is 6MPa, the temperature is 45 ℃, the oil yield and free of the garlic The content of neural acid was used as an indicator, and the trends of extraction pressures of 15, 25, 35, and 45 MPa were observed.
Under the same conditions, the supercritical cycle extraction pressure increases, and the oil yield increases. However, when the extraction pressure reaches 35 MPa, the oil yield does not increase significantly. The oil yield at 45 MPa is lower than that at 35 MPa. The content of free neuroacid did not increase significantly. When the pressure reached above 25MPa, the content decreased.
Supercritical CO2 extraction orthogonal test
After a single-factor test, the oil yield and free neuroacid content of garlic fruits did not increase much after 2 hours of extraction, and the extraction time was determined to be 2 hours.
Take the garlic fruits, crush them through an 8-mesh sieve, weigh 9 parts, each 120g, and carry out the supercritical extraction orthogonal test.
The results of orthogonal test of supercritical CO2 extraction determined that the optimal process was extraction pressure of 35 MPa and extraction temperature of 45 ° C; pressure of separation kettle I was 6 MPa and temperature 55 ° C; pressure of separation kettle II was 6 MPa and temperature 55 ° C.
Garlic has a lot of oil content and high water content. It is easy to stick when crushed, and it needs to be crushed with other materials. When extracting single-flavored medicinal materials, because the main components of garlic oil are fatty acids and fatty acid esters, excipients containing metal ions cannot be used, and only inert excipients can be used for crushing. In addition, garlic fruit also contains a large amount of starch. If starch is added as an auxiliary string oil, the amount of starch is too much, and the starch dissolves in the oil to form a paste, which affects the quality of the oil. Although the material dispersibility is improved, the extraction process is prone to flushing, and the starch will block the pipeline and damage the equipment after extraction. Adopting frozen crushing method, the materials are evenly dispersed and the particle size is moderate.
The crushed particle size of garlic is better when the mesh size is 8 meshes. The extracted residue is white and the oil is transparent and golden. When the crushed particle size is 14 meshes, although the extraction is complete and the residue is white, there is a small amount of precipitation in the oil, which affects the quality.
Through single-factor test and orthogonal test, the optimal technology for supercritical CO2 extraction of garlic fruit is: extraction pressure 35MPa, extraction temperature 45 ℃; separation kettle I pressure is 6MPa, temperature 55 ℃; separation kettle II pressure is 6MPa, temperature 55 ℃. The process is stable and feasible with good repeatability.
The fatty acids in garlic oil were analyzed by GC-MS, and 12 fatty acid components were identified. The content of neural acid is relatively high, accounting for about 35% of the total fatty acids.
Using saponification and crystallization combined method to separate neural acid from garlic oil, a crystal with a yield of 4.6% and a neural acid content of 96% can be obtained.