Views: 2 Author: Site Editor Publish Time: 2022-08-23 Origin: Site
1. Supercritical Fluid Extraction (SFE)
SFE is especially suitable for the extraction and separation of natural substances rich in biological activity. It uses supercritical fluid as the extraction medium, uses the solvation effect of supercritical fluid to dissolve the liquid or solid mixture to be separated, and then reduces the pressure by reducing the pressure or adjusting the temperature. Its density, thereby reducing its solvent capacity, allows the extract to be separated.
SFE is widely used in the fields of food, medicine and chemical industry due to its simple separation process and high extraction efficiency. Among them, the SFE technology using CO2 as a solvent has strong dissolving ability and good selectivity for organic substances, and CO2 is non-toxic and inert , easy to obtain, has become the most important research and application technology in SFE technology.
The supercritical CO2 method is used to extract piperine in pepper. The research shows that the optimal extraction process conditions are as follows: the extraction temperature is 40℃, the pressure is 200bar, the addition amount of anhydrous ethanol is 7.5% (V:V), and the CO2 constant solvent flow rate is (8±2) g/min.
The supercritical CO2 method is used to extract piperine in pepper. The optimal conditions for extracting piperine from 20g of pepper powder with an average particle size of 0.42mm are as follows: the extraction temperature is 60°C, the pressure is 300bar, the extraction time is 45min, and the flow rate of CO2 is 2L/min.
Grinevicius et al. used supercritical CO2 method to extract antitumor active substances from black pepper. The study showed that its main components are piperine and terpenoids. When the extraction temperature is 40℃, the pressure is 200bar, and the CO2 flow rate is (8±2) At g/min, the antitumor activity of the extract was the highest, and the content of piperine in the extract was also the highest (6.035±0.014)%.
2. Enzyme-assisted supercritical carbon dioxide extraction
Enzyme-assisted supercritical carbon dioxide extraction technology is a relatively new experimental method, which can more effectively improve the extraction yield of piperine. This method was used to extract piperine from black pepper, and the enzyme used was α-amylase (from Bacillus licheniformis). The changes in the yield of piperine extract before and after enzyme addition were compared, and optimization experiments were carried out in batch and continuous modes. .
The research shows that the optimal enzyme ratio is: enzyme amount: black pepper powder = 1:5000, time is 2.25h, and CO2 flow rate is 2L/min. In the continuous mode, the specific activity of the enzyme was increased by 2.13 times, and the batch mode showed a 1.25-fold increase, and the yield of piperine extract was significantly increased.
3. Enzymatic extraction
Enzymatic extraction of active substances from Chinese herbal medicines is a major development in the extraction process. In recent years, there have been many studies on the extraction of active ingredients from plants by enzymatic technology. Among them, cellulase is the most widely used and has a relatively significant effect. The main components of plant cell wall are cellulose and pectin, and the addition of cellulase can effectively destroy the cell wall, which is beneficial to the dissolution of active components in cells.
The use of ultrasonic-assisted enzymatic method can further strengthen the enzymatic hydrolysis of cellulose and improve the extraction rate of target substances. Cellulase was used to extract piperine in white pepper, and the conditions were optimized on the basis of single factor experiment. The optimal process for extracting piperine from 3.0g white pepper powder was determined as follows: cellulase 6mg, enzymatic hydrolysis temperature 50℃ , the pH value of the enzymatic hydrolysis solution is 7, and the time is 6h. Under this condition, the content of piperine in the extract can reach 5.29%.
4. Organic solvent method
Piperine is almost insoluble in water, slightly soluble in acetic acid, soluble in benzene or acetic acid, and easily soluble in chloroform and ethanol, so it can be extracted by organic solvent method. Using 85% ethanol to extract piperine in pepper, the optimal process conditions are determined as: reflux extraction twice, ethanol (volume): pepper (mass) is 10:1, the filtrates are combined, concentrated, dynamically cooled for crystallization, anhydrous ethanol After repeated crystallization, the purity of the extracted piperine is more than 98%. Using methanol as the extraction solvent, the Soxhlet extraction technique was used to extract the piperine in the pepper, and the content of the crude piperine was measured to be 3.80%.
5. Ultrasonic-assisted organic solvent extraction
Ultrasonic-assisted organic solvent extraction is a modern separation method. The cavitation of ultrasonic waves will generate great pressure, improve the permeability of the cell wall, and help the rapid release of active ingredients in cells. At the same time, the vibration effect and thermal effect of ultrasonic can increase the mass transfer coefficient, increase the contact area of the solute, and then increase the solubility of the solute. This method has the advantages of short time, high efficiency and can be carried out at room temperature, and is widely used in the extraction and separation of natural materials.
Piperine was extracted from pepper by ultrasonic-assisted organic solvent method. Ethanol was used as the extraction solvent. The extraction time was 18 min, the solid-liquid ratio was 1:10, the ultrasonic power was 125 W, the ultrasonic frequency was 25 kHz, and the temperature was 50 °C. Studies have shown that the extraction efficiency of piperine is higher than that of traditional organic solvent extraction methods.
The optimal process conditions were as follows: the volume fraction of ethanol was 95%, the extraction time was 45min, the extraction temperature was 70℃, and the ratio of solid to liquid was 1:30 (g:mL).
Under this condition, the content of piperine in the extract can reach 6.12%. 1.6 Pressurized liquid extraction (PLE) Pressurized liquid extraction (PLE) is extracted by continuous solvent flowing through a fixed extraction column containing solid particles, which is characterized by less solvent and higher extraction efficiency. Extraction time can also be reduced. Using ethanol as the PLE solvent, 20 g of ground black pepper powder was put into the extraction vessel, the pressure was set to 100 bar, the temperature was 40 °C, the flow rate of B was kept at 3 mL/min, and the extraction time was 60 min.
6. Ultrasonic-assisted extraction of ionic liquids (ILUAE)
The effects of alkyl chain length and anion species on the extraction efficiency of piperine were evaluated by ultrasonic-assisted extraction (ILUAE) based on a series of 1-alkyl-3-methylimidazolium ionic liquids. It shows that it has a significant effect on the extraction efficiency of piperine.
7. Microwave-assisted organic solvent extraction
The principle of the microwave-assisted organic solvent extraction method is based on the ions and molecules in the solution receiving microwave radiation to obtain energy and heating up, thereby improving the ability of the solute to enter the solvent. The advantages of this method are low energy consumption, short time, high efficiency and can be Save the amount of extractant used. The piperine in pepper was extracted by microwave-assisted organic solvent method, and the optimal extraction process was determined as follows: the concentration of ethanol is 80%, the microwave power is 500W, the extraction time is 60min, the extraction temperature is 55℃, and the ratio of material to liquid is 80:50. Under the conditions, the content of piperine in the extract can reach 4.12%.
8. Ultrasonic-microwave synergistic extraction
The ultrasonic-microwave synergistic extraction instrument is equipped with a condensation device, which can greatly improve the yield of piperine oleoresin in piperine and reduce the loss of its volatile components. Using black pepper as the main raw material, the effects of extraction methods such as thermal reflux extraction, Soxhlet extraction and ultrasonic-microwave-assisted extraction on the yield of pepper oleoresin were studied, and the content of piperine was determined by HPLC analysis.
The results showed that there were significant differences in the contents of pepper oleoresin and piperine obtained by different extraction methods, and the yield of pepper oleoresin obtained by ultrasonic-microwave synergistic extraction was the highest.
9. Acid hydrolysis
Piperine is basically insoluble in water, and can be extracted by adding acid to the water to convert piperine into the corresponding piperine salt and dissolve in water. Using acetic acid as the extraction solution to extract piperine from black pepper, 15g black pepper uses 500g solvent, and the content of piperine in the extract can reach 3.0%.