A method for multi-stage continuous high-temperature and high-pressure extraction of natural components in plants
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHAO YANG HUA CHENG LV GUO SHENG WU KE JI YOU XIAN GONG SI
- Filing Date
- 2023-10-16
- Publication Date
- 2026-06-26
Smart Images
Figure CN117101178B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of natural product extraction technology, specifically to a method for multi-stage continuous high-temperature and high-pressure extraction of natural components from plants. Background Technology
[0002] Water is hailed as the "source of life," an inexhaustible natural resource and an excellent solvent that can stabilize and preserve the activity and stability of substances over a long period of time, thus becoming an important technological condition in fields such as life sciences, agricultural sciences, and industrial sciences.
[0003] The polarity of a substance can be determined by its dielectric constant. Generally, substances with a relative dielectric constant greater than 3.6 F / m are polar; those with a relative dielectric constant in the range of 2.8–3.6 F / m are weakly polar; and those with a relative dielectric constant less than 2.8 F / m are nonpolar. At room temperature and pressure, water is a strongly polar compound with a dielectric constant of 78.36 F / m. For example, at a pressure of 0.505 MPa and a temperature of 50°C to 300°C (transitioning water from its normal state to a subcritical state), the dielectric constant of water drops sharply to 1 as the temperature increases. This shows that in the subcritical state, water becomes a nonpolar fluid. Therefore, by controlling the pressure and temperature of water, transitioning it from its normal state to a subcritical state, the polarity of water gradually changes from strongly polar to nonpolar, allowing various chemical components to be extracted in descending order of polarity. Under low temperature and pressure conditions, water has a higher polarity, allowing for the extraction of polar components; under high temperature and pressure conditions, water's polarity decreases, allowing for the extraction of non-polar components. Therefore, for different raw materials, by controlling the temperature and pressure of water to achieve the appropriate polarity, both polar components that are normally soluble in water and non-polar components that are normally insoluble in water can be extracted, thereby greatly increasing the variety and quantity of chemical components extracted from the raw materials.
[0004] In the field of natural product production and processing, water is used as the extraction solvent for many plant extracts. Extraction methods or techniques using water as a solvent include traditional fractional heating extraction, microwave-assisted extraction, ultrasonic extraction, percolation extraction, Soxhlet extraction, countercurrent extraction, and pulping extraction, among others. However, all of these methods have drawbacks to varying degrees, such as low extraction rates, high water consumption, and low extract concentrations.
[0005] The inventor's previous patent CN116496339A, "An Industrial Production Method of Pesticide-Residue-Free Luo Han Guo Extract," describes a process where superheated water is introduced during extraction. While the superheated water in the closed pipe is indeed in a subcritical state, the superheated water pulping and extraction process in this patent occurs instantaneously as the superheated water transitions from subcritical to normal pressure. It utilizes the high temperature of the superheated water and the instantaneous energy and heat generated by the release of the superheated water pressure to normal pressure to complete the heat transfer and extraction process. Therefore, it is not a subcritical extraction in the strict sense.
[0006] There are also reports of using subcritical extraction to extract natural products in the existing technology, but the extraction efficiency is often low, the liquid-to-solid ratio is high, and a lot of solvent is wasted. Summary of the Invention
[0007] The technical problem to be solved by the present invention is to overcome the various defects in the extraction of natural product components from plants in the prior art, and to provide a method for multi-stage continuous high temperature and high pressure extraction of natural components from plants.
[0008] The technical solution adopted by this invention to solve its technical problem is as follows: A method for multi-stage continuous high-temperature and high-pressure extraction of natural components from plants, comprising the following steps:
[0009] (1) Plant raw materials are simultaneously put into multiple high-temperature and high-pressure extraction tanks connected in series. High-pressure superheated water is introduced into the first high-temperature and high-pressure extraction tank S1. The extract flowing out of S1 enters the second high-temperature and high-pressure extraction tank S2. Then the extract flowing out of each high-temperature and high-pressure extraction tank enters the next high-temperature and high-pressure extraction tank in sequence until the nth high-temperature and high-pressure extraction tank Sn. The first extract is collected from the nth high-temperature and high-pressure extraction tank Sn. After the natural components of the plant raw materials in the first high-temperature and high-pressure extraction tank S1 are fully extracted, the first round of high-temperature and high-pressure extraction is completed.
[0010] (2) The first high temperature and high pressure extraction tank S1 is depressurized and slag is discharged. Plant raw materials are put back in and the high pressure superheated water enters the second high temperature and high pressure extraction tank S2. Then it enters the next high temperature and high pressure extraction tank in sequence until the nth high temperature and high pressure extraction tank Sn. The extract flowing out of the nth high temperature and high pressure extraction tank Sn enters the first high temperature and high pressure extraction tank S1. The second extract is collected from the first high temperature and high pressure extraction tank S1. At this time, the natural components of the plant raw materials in the second high temperature and high pressure extraction tank S2 are fully extracted, and the second round of high temperature and high pressure extraction is completed.
[0011] (3) Repeatedly cycle the operation. During each round of high temperature and high pressure extraction, the hot water is put into the next high temperature and high pressure extraction tank after the plant raw materials are put back in. Then it is put into the high temperature and high pressure extraction tank in sequence until the plant raw materials are put back in the high temperature and high pressure extraction tank. The extract is collected. This cycle is repeated until all the plant raw materials are put in. The extract is collected and combined to complete the extraction of natural components from the plants.
[0012] Preferably, the plant materials include, but are not limited to, monk fruit, sweet tea, stevia, and tea leaves.
[0013] Preferably, the temperature of the high-pressure superheated water is greater than 100 to 250°C, and the ambient pressure of the high-pressure superheated water is 0.2-22.0 MPa. The high-temperature and high-pressure extraction tank is equipped with a steam jacket insulation device, which can supplement heat and maintain the temperature.
[0014] More preferably, the temperature of the high-pressure superheated water is 105-200℃, and the ambient pressure of the high-pressure superheated water is 1-5 MPa.
[0015] More preferably, the temperature of the high-pressure superheated water is 110-150℃, and the ambient pressure of the high-pressure superheated water is 2-3 MPa.
[0016] Preferably, during the first round of high-temperature and high-pressure extraction, the liquid-to-material ratio is 1-5:1, more preferably 1.5-2:1. This liquid-to-material ratio is the ratio of the total volume of superheated water used to the total mass of plant material in the series-connected high-temperature and high-pressure extraction tanks, i.e., 1-5L:1kg, more preferably 1.5-2L:1kg. In each subsequent round of high-temperature and high-pressure extraction, the liquid-to-material ratio remains essentially the same, i.e., the ratio of the volume of injected superheated water to the mass of newly added plant material is 1-5L:1kg, more preferably 1.5-2L:1kg. Furthermore, the difference in the liquid-to-material ratio between each round of high-temperature and high-pressure extraction should not exceed 10%, more preferably 5%, and more preferably 2%. Taking monk fruit as an example, this invention uses repeated circulation of high-pressure superheated water. At a liquid-to-material ratio of 1.5:1, monk fruit extract can be obtained efficiently, rapidly, and with a high yield. In addition to mogroside V, due to the characteristics of subcritical extraction, beneficial active ingredients including but not limited to kaempferol, kaempferol glycoside, β-sitosterol, linoleic acid, and squalene can also be obtained. These components are often wasted in waste liquid or residue during traditional monk fruit extraction processes. Research has found that squalene, β-sitosterol, and linoleic acid all possess different physiological activities for human health and are also economically valuable active ingredients in monk fruit resources. Existing literature on the extraction of these low-polarity active ingredients (such as squalene, β-sitosterol, and linoleic acid) from monk fruit residue involves changing the organic solvent and re-extracting from the residue, which inevitably increases production costs. While existing technologies also target the extraction of multiple active ingredients, these processes are complex and require various equipment and solvents. The equipment of this invention uses only a series of high-temperature, high-pressure extraction tanks, a feeding system, and an extract collection system to achieve continuous operation and simultaneously extract multiple active ingredients from the plant.
[0017] Except for the first round of high-temperature and high-pressure extraction, in each subsequent extraction round, the newly injected high-pressure superheated water is 100-150% of the volume of a single high-temperature and high-pressure extraction tank, preferably 100-120%. Furthermore, the newly injected high-pressure superheated water is 6-30% of the total volume of all the high-temperature and high-pressure extraction tanks connected in series, preferably 10-15%, such as 11%, 12%, 12.5%, 13%, and 14%. For example, for a 6L extraction tank, except for the first round of high-temperature and high-pressure extraction, in each subsequent round of high-temperature and high-pressure extraction, the newly injected high-pressure superheated water is 6-9L, preferably 6-7L.
[0018] Preferably, in each high-temperature and high-pressure extraction tank, the ratio of the feed mass of plant raw material to the solvent in the extraction tank is 1kg:1-2L, for example, 1kg:1.5L.
[0019] Preferably, the number of multiple high-temperature and high-pressure extraction tanks n connected in series is 5-15, such as 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 extraction tanks. The volume of the extraction tanks, the number of extraction tanks, and the amount of plant material fed into the extraction tanks meet the following requirements: after the total volume of liquid phase (using the circulating extractant and the supplemented high-pressure superheated water) of the multiple extraction tanks connected in series is passed through each extraction tank, the plant material in the extraction tank can be fully extracted.
[0020] According to the steps of this invention, the solvent used, i.e., the liquid-to-material ratio of high-pressure superheated water and plant raw materials, is 1-5:1, and in preferred embodiments, it can reach 1.5-2:1. In general, existing subcritical extraction techniques use a liquid-to-material ratio of 10-30:1 to achieve satisfactory extraction efficiency and yield, resulting in significant solvent waste and increased processing costs and equipment footprint. This invention utilizes a cyclic high-temperature, high-pressure extraction technology. After each round of high-temperature, high-pressure extraction, the next round of high-pressure superheated water enters from the extraction tank immediately following the one where the plant raw materials were previously added. The effluent then sequentially enters the next extraction tank in series until the previous round of extraction where the plant raw materials were previously added again. This completes one cycle, and the high-temperature, high-pressure extraction cycle is repeated until all the plant raw materials have been added. This invention maintains a consistent liquid-to-material ratio in each round of high-temperature, high-pressure extraction, and the superheated water is injected into the extraction tank immediately following the one where the plant raw materials were previously added.
[0021] Preferably, the relative flow rate of the high-pressure superheated water continuously passing through the high-temperature and high-pressure extraction tank is 0.1-5.0 L / kg of raw material per hour, more preferably 2-3 L / kg of raw material per hour, that is, the flow rate per hour is 2-3 times the weight of the raw material (volume / mass ratio, L / kg).
[0022] In this invention, the flow direction of the high-pressure superheated water and extract in each extraction tank can be selected according to the properties of the raw materials. It can be bottom-in, top-out, or top-in, bottom-out; or it can enter from the side and exit from the other side. Considering the prevention of fine extraction residue clogging the bottom screen and maintaining smooth flow of liquid materials, the bottom-in, top-out method is preferred.
[0023] The design principle of this invention is based on multiple extraction tanks connected in series. The extract from one tank flows into the next, allowing for continuous operation. The concentration of the extract gradually increases. Since the initial tank receives the most water (or the amount of extract used), it is the first to be fully extracted and discharged, allowing for the addition of new plant material. After replenishment, the process follows a cycle of "first in, first out; last in, last out," with each tank receiving a fixed volume of liquid phase (the liquid phase from the used tank and the newly added high-pressure superheated water) until all plant material is extracted. This method significantly reduces the liquid-to-material ratio, saving solvent, reducing equipment load, and simplifying operation. Furthermore, it yields an extract rich in multiple active ingredients in a single step, overcoming the shortcomings of previous methods that only targeted the primary extraction target and wasted byproducts.
[0024] In a preferred embodiment of the present invention, a method for multi-stage continuous high-temperature and high-pressure extraction of monk fruit is provided, comprising the following steps:
[0025] (T1) First round of feeding: The crushed monk fruit raw material is simultaneously fed into multiple high temperature and high pressure extraction tanks connected in series;
[0026] (T2) First round of multi-stage high temperature and high pressure extraction: High-pressure superheated water enters from the bottom of the first high temperature and high pressure extraction tank S1 and flows out from the top; the extract flowing out from the top of S1 enters from the bottom of the second high temperature and high pressure extraction tank S2 and flows out from the top. Then the extract flowing out from the top of each extraction tank enters the next extraction tank through the bottom of the next extraction tank, until the last high temperature and high pressure extraction tank Sn. The extract flows out from the top of Sn to obtain the first extract, which is collected and set aside for use.
[0027] (T3) First round of slag discharge and second round of feeding: When the cumulative high-pressure superheated water flow into the high-temperature and high-pressure extraction tank S1 reaches the total volume of multiple series extraction tanks, the raw material in the high-temperature and high-pressure extraction tank S1 has fully completed the extraction process. Close the valves at the top and bottom of the high-temperature and high-pressure extraction tank S1, depressurize, discharge slag, and re-feed the monk fruit raw material.
[0028] (T4) Second round of multi-stage high temperature and high pressure extraction: High-pressure superheated water enters from the bottom of high temperature and high pressure extraction tank S2 and flows out from the top; the extract flowing out from the top of S2 enters from the bottom of the third high temperature and high pressure extraction tank S3 and flows out from the top; thereafter, the extract flowing out from the top of each extraction tank enters the next extraction tank through the bottom of the next extraction tank; in this way, after the extract from high temperature and high pressure extraction tank Sn flows out from the top, it enters from the bottom of high temperature and high pressure extraction tank S1 and flows out from the top to obtain the second extract, which is collected and ready for use;
[0029] (T5) Second round of slag discharge and third round of feeding: Close the valves at the top and bottom of the high temperature and high pressure extraction tank S2, depressurize, discharge slag, and re-feed the monk fruit raw material;
[0030] (T6) Continuous slag discharge, feeding, and high-temperature and high-pressure extraction. During each round of high-temperature and high-pressure extraction, high-pressure superheated water enters from the bottom of the next extraction tank after the material is re-fed and flows out from the top. The outflowing liquid enters the next extraction tank in sequence until it enters the high-temperature and high-pressure extraction tank where the plant raw materials are re-fed. This process is repeated until all the monk fruit raw materials are fed in. The extract is collected and combined to complete the high-temperature and high-pressure extraction of monk fruit.
[0031] Furthermore, the number n of the plurality of high-temperature and high-pressure extraction tanks connected in series is an integer from 5 to 15. For example, the number of extraction tanks is 6, 7, 8, 9, or 10.
[0032] Furthermore, in each extraction tank, the ratio of the mass of the monk fruit raw material to the volume of the extraction tank is 1 kg: 1-2 L, preferably 1 kg: 1.5-2 L.
[0033] Furthermore, in the multi-stage continuous high-temperature and high-pressure extraction method for monk fruit, in the first round of high-temperature and high-pressure extraction, the ratio of the total volume of high-pressure superheated water added to the total mass of monk fruit raw material is 1-2L:1kg, preferably 1.5-2L:1kg; in each subsequent round of high-temperature and high-pressure extraction, the ratio of the newly added volume of high-pressure superheated water to the newly added mass of monk fruit raw material is 1-2L:1kg, preferably 1.5-2L:1kg, and the difference in the liquid-to-material ratio in each round of high-temperature and high-pressure extraction does not exceed 10%, preferably not more than 5%, and more preferably not more than 2%. This operation essentially ensures that the liquid-to-material ratio in each round of high-temperature and high-pressure extraction is close to 1-2:1, preferably 1.5-2:1.
[0034] Furthermore, in step (T2), the total volume of high-pressure superheated water used is 100%-110% of the total volume of multiple high-temperature and high-pressure extraction tanks connected in series; in step (T4), the volume of newly injected high-pressure superheated water used is 100-120% of the volume of a single high-temperature and high-pressure extraction tank, and each newly injected high-pressure superheated water is 10-15% of the total volume of all the high-temperature and high-pressure extraction tanks connected in series, such as 11%, 12%, 12.5%, 13%, and 14%.
[0035] The principle of the method of this invention is:
[0036] By controlling the pressure and temperature of water, transitioning it from a normal state to a subcritical state, the polarity of water gradually changes from strongly polar to non-polar, allowing various chemical components to be extracted in descending order of polarity. Under lower temperature and pressure conditions, water has higher polarity, enabling the extraction of polar components; under higher temperature and pressure conditions, water's polarity decreases, allowing the extraction of non-polar components. Therefore, for different raw materials, by controlling the temperature and pressure of water to achieve the appropriate polarity, both polar components that are normally soluble in water and non-polar components that are normally insoluble in water can be extracted, thereby significantly increasing the variety and quantity of chemical components extracted from the raw materials.
[0037] The beneficial effects of the method of the present invention are as follows:
[0038] (1) The method of the present invention can significantly reduce the liquid-to-solid ratio, reduce the amount of solvent used, and increase the extraction rate; reduce the equipment footprint and simplify the equipment and process flow; only multiple high-temperature and high-pressure extraction devices connected in series are needed.
[0039] (2) Due to the reduction in water consumption and the increase in extraction rate, the concentration of the extract obtained by this method is greatly improved, thereby reducing the processing volume and providing convenience for subsequent processes of plant extract processing.
[0040] (3) It has a high extraction yield and can simultaneously extract plant extracts rich in a variety of active ingredients.
[0041] (4) The high concentration of the extract reduces the amount of subsequent material concentration and processing; it saves water and reduces the discharge of wastewater, making it environmentally friendly; and it does not require the use of flammable and explosive organic solvents when extracting low-polarity active natural components, making it green and safe. Attached Figure Description
[0042] Figure 1 This is a schematic diagram of the first four rounds of high-temperature and high-pressure extraction process in Example 1. Detailed Implementation
[0043] The present invention will be further described below with reference to the embodiments.
[0044] The fresh monk fruit used in this embodiment of the invention was purchased from the monk fruit planting base of Hunan Huacheng Biological Resources Co., Ltd.; wherein, the mass percentage content of mogroside V is 0.46%, kaempferol is 0.02%, kaempferol glycoside is 0.01%, β-sitosterol is 0.02%, linoleic acid is 0.04%, and squalene is 0.03%; unless otherwise specified, the chemical reagents used in this embodiment of the invention were obtained through conventional commercial channels.
[0045] In this embodiment of the invention, the method for detecting the solid content is the loss on drying method, and the method for detecting the content of mogroside V, kaempferol, kaempferol glycoside, β-sitosterol, linoleic acid and squalene is the high performance liquid chromatography (HPLC) external standard method.
[0046] Example 1
[0047] This embodiment uses an eight-stage continuous high-temperature and high-pressure extraction device as an example. Each high-temperature and high-pressure extraction tank has a volume of 6L (a total of 8 extraction tanks). Fresh monk fruit is used as raw material, and the following extraction operations are performed:
[0048] (1) First round of feeding: The crushed fresh monk fruit raw material is simultaneously fed into 8 high temperature and high pressure extraction tanks connected in series, with 4 kg added to each tank, which occupies about 2L of the extraction tank volume;
[0049] (2) First-round multi-stage high-temperature and high-pressure extraction: 120℃ high-pressure superheated water enters from the bottom of the first high-temperature and high-pressure extraction tank S1 and flows out from the top; the extract from S1 enters from the bottom of the second high-temperature and high-pressure extraction tank S2 and flows out from the top; the extract from S2 enters from the bottom of the third high-temperature and high-pressure extraction tank S3 and flows out from the top; the extract from S3 enters from the bottom of the fourth high-temperature and high-pressure extraction tank S4 and flows out from the top; this process continues until the final extract from this round flows out from the top of the high-temperature and high-pressure extraction tank S8. The pressure in each extraction tank system is adjusted to maintain a pressure of 2.2±0.05Mpa throughout the entire multi-round continuous extraction process. After pressure equilibrium is achieved, the superheated water flow rate is controlled at 6L / hour. The extract from the first round of multi-stage high-temperature and high-pressure extraction is collected in an extract storage tank for later use.
[0050] (3) First round of slag discharge and second round of feeding: According to the process settings, when the cumulative high-pressure superheated water flow into the high-temperature and high-pressure extraction tank S1 reaches the process requirements (i.e., the cumulative water flow into S1 reaches 48L), the raw material in the high-temperature and high-pressure extraction tank S1 has fully completed the extraction process. Close the valves at the top and bottom of the high-temperature and high-pressure extraction tank S1, depressurize, discharge slag, and re-feed 4kg of crushed fresh monk fruit raw material.
[0051] (4) Second round of multi-stage high temperature and high pressure extraction: 6L of 120℃ high-pressure superheated water enters from the bottom of the high temperature and high pressure extraction tank S2 and flows out from the top; the extract of S2 enters from the bottom of the high temperature and high pressure extraction tank S3 and flows out from the top; the extract of S3 enters from the bottom of the high temperature and high pressure extraction tank S4 and flows out from the top; following this method, after the extract of the high temperature and high pressure extraction tank S8 flows out from the top, it does not directly enter the extract storage tank, but enters from the bottom of the high temperature and high pressure extraction tank S1 and flows out from the top to obtain the extract of the second round of multi-stage high temperature and high pressure extraction, which then enters the extract storage tank for collection and later use;
[0052] (5) Second round of slag discharge and third round of feeding: According to the process settings, when the cumulative high-pressure superheated water flow into the high-temperature and high-pressure extraction tank S2 is 48L (that is: 42L of extract from S1 in the first round and 6L of superheated water newly introduced in the second round, totaling 48L), the raw material in the high-temperature and high-pressure extraction tank S2 has fully completed the extraction process. Close the valves at the top and bottom of the high-temperature and high-pressure extraction tank S2, depressurize, discharge slag, and re-input 4kg of crushed fresh monk fruit raw material;
[0053] (6) Third round of multi-stage high temperature and high pressure extraction: 6L of 120℃ high-pressure superheated water enters from the bottom of the third high temperature and high pressure extraction tank S3 and flows out from the top; the extract of S3 enters from the bottom of the high temperature and high pressure extraction tank S4 and flows out from the top; the extract of S4 enters from the bottom of the high temperature and high pressure extraction tank S5 and flows out from the top; in this way, the extract of the high temperature and high pressure extraction tank S8 enters from the bottom of the high temperature and high pressure extraction tank S1 and flows out from the top; the extract of S1 enters from the bottom of the high temperature and high pressure extraction tank S2 and flows out from the top, thus obtaining the final extract of the third round of multi-stage high temperature and high pressure extraction, which is then collected in the extract storage tank for later use;
[0054] (7) Third round of slag discharge and fourth round of feeding: According to the process settings, when the cumulative high-pressure superheated water flow into the high-temperature and high-pressure extraction tank S3 is 48L (36L of extract from S2 in the first round, 6L of extract from S2 in the second round, and 6L of superheated water newly introduced in the third round, totaling 48L), the raw material in the high-temperature and high-pressure extraction tank S3 has fully completed the extraction process. Close the valves at the top and bottom of the high-temperature and high-pressure extraction tank S3, depressurize, discharge slag, and re-introduce 4kg of crushed fresh monk fruit raw material;
[0055] (8) This cycle continues until all 100 kg of fresh monk fruit raw materials have been fed. The extract collected in the extraction tank and the liquid phases in the 8 extraction tanks are weighed together and weighed to a total of 159 kg. According to calculations, the total amount of water used in this embodiment is approximately 1.5 times the weight of the fresh monk fruit raw materials.
[0056] Figure 1 This is a schematic diagram of the first four rounds of high-temperature and high-pressure extraction process in Example 1.
[0057] According to the loss on drying method, the solid content of the extract obtained in this example was 6.70%. According to the external standard method of high performance liquid chromatography (HPLC), the content of mogroside V in the extract obtained in this example was 0.2877%, and the extraction rate of mogroside V was 99.10%; the content of kaempferol was 0.0106%, and the extraction rate of kaempferol was 85.20%; the content of kaempferol glycoside was 0.0048%, and the extraction rate of kaempferol glycoside was 76.32%; the content of β-sitosterol was 0.0085%, and the extraction rate of β-sitosterol was 67.58%; the content of linoleic acid was 0.0182%, and the extraction rate of linoleic acid was 72.35%; and the content of squalene was 0.0126%, and the extraction rate of squalene was 66.78%.
[0058] Example 2
[0059] Other conditions and operations were the same as in Example 1, except that different temperatures and pressures, as well as liquid-to-solid ratios, were adjusted during the multi-round series high-temperature and high-pressure extraction. The results are shown in Table 1 below:
[0060] Table 1. Extraction yield of monk fruit under different conditions
[0061]
[0062]
[0063] Comparative Example 1
[0064] 100 kg of fresh monk fruit was crushed and subjected to countercurrent extraction with hot water at 95°C, yielding 420 kg of countercurrent extract. Calculations show that the total amount of water used in this embodiment is approximately four times the weight of the fresh monk fruit raw material.
[0065] The solid content of the extract obtained in this comparative example was 2.28% as determined by the loss on drying method. The extract obtained in this comparative example was found to contain 0.1008% mogroside V (extraction rate of 92.03%), 0.0006% kaempferol (extraction rate of 12.60%), 0.0002% kaempferol glycoside (extraction rate of 8.4%), and was undetectable in β-sitosterol (extraction rate of 0%). It was also undetectable in linoleic acid (extraction rate of 0%) and squalene (extraction rate of 0%).
Claims
1. A method for multi-stage continuous high-temperature and high-pressure extraction of monk fruit, characterized in that, Includes the following steps: (T1) First round of feeding: The crushed monk fruit raw material is simultaneously fed into 8-10 high temperature and high pressure extraction tanks connected in series; (T2) First-stage multi-stage high-temperature and high-pressure extraction: High-pressure superheated water enters from the bottom of the first high-temperature and high-pressure extraction tank S1 and flows out from the top; the extract flowing out from the top of S1 enters from the bottom of the second high-temperature and high-pressure extraction tank S2 and flows out from the top. Then, the extract flowing out from the top of each extraction tank enters the next extraction tank through the bottom of the next extraction tank, until the last high-temperature and high-pressure extraction tank Sn. The extract flows out from the top of Sn to obtain the first extract, which is collected and set aside for later use; the total volume of high-pressure superheated water used is 100% of the total volume of multiple high-temperature and high-pressure extraction tanks connected in series. (T3) First round of slag discharge and second round of feeding: When the cumulative high-pressure superheated water flow into the high-temperature and high-pressure extraction tank S1 reaches the total volume of multiple series extraction tanks, the raw material in the high-temperature and high-pressure extraction tank S1 has fully completed the extraction process. Close the valves at the top and bottom of the high-temperature and high-pressure extraction tank S1, depressurize, discharge slag, and re-feed the monk fruit raw material. (T4) Second round of multi-stage high-temperature and high-pressure extraction: High-pressure superheated water enters from the bottom of high-temperature and high-pressure extraction tank S2 and flows out from the top; the extract flowing out from the top of S2 enters from the bottom of the third high-temperature and high-pressure extraction tank S3 and flows out from the top; thereafter, the extract flowing out from the top of each extraction tank enters the next extraction tank through the bottom of the next extraction tank; in this way, after the extract from high-temperature and high-pressure extraction tank Sn flows out from the top, it enters from the bottom of high-temperature and high-pressure extraction tank S1 and flows out from the top to obtain the second extract, which is collected and set aside for later use; the volume of newly injected high-pressure superheated water is 100-120% of the volume of a single high-temperature and high-pressure extraction tank, and the newly injected high-pressure superheated water each time is 10-15% of the total volume of all the high-temperature and high-pressure extraction tanks connected in series; (T5) Second round of slag discharge and third round of feeding: Close the valves at the top and bottom of the high-temperature and high-pressure extraction tank S2, depressurize, discharge slag, and re-feed the monk fruit raw material; (T6) Continuous circulation of slag discharge, feeding, and high-temperature and high-pressure extraction. During each round of high-temperature and high-pressure extraction, high-pressure superheated water enters from the bottom of the next extraction tank after the material is re-fed and flows out from the top. The effluent enters the next extraction tank in sequence until it enters the high-temperature and high-pressure extraction tank where the plant raw materials are re-fed. This process is repeated multiple times until all the monk fruit raw materials are fed in. The extract is collected and combined to complete the high-temperature and high-pressure extraction of monk fruit. The temperature of the high-pressure superheated water is 110-150℃, and the ambient pressure of the high-pressure superheated water is 2-3 MPa; the relative flow rate of the high-pressure superheated water continuously passing through the high-temperature and high-pressure extraction tank is 2-3 L / kg of raw material per hour; In each extraction tank, the ratio of the mass of the monk fruit raw material to the tank volume is 1 kg: 1-2 L; the ratio of the total volume of the added high-pressure superheated water to the total mass of the monk fruit raw material is 1-2 L: 1 kg; in each subsequent round of high-temperature and high-pressure extraction, the ratio of the newly added high-pressure superheated water volume to the newly added monk fruit raw material is 1-2 L: 1 kg; and the liquid-to-material ratio difference in each round of high-temperature and high-pressure extraction does not exceed 10%.
2. The method according to claim 1, characterized in that, In the first round of high-temperature and high-pressure extraction, the ratio of the total volume of high-pressure superheated water added to the total mass of monk fruit raw material is 1.5-2L:1kg; in each subsequent round of high-temperature and high-pressure extraction, the ratio of the newly added volume of high-pressure superheated water to the newly added monk fruit raw material is 1.5-2L:1kg, and the difference in liquid-to-material ratio in each round of high-temperature and high-pressure extraction does not exceed 5%.