Solvent-free supercritical fluid extraction system

Abstract

A solvent-free supercritical fluid extraction system is characterized by comprising: a pretreatment unit having a cleaning device for cleaning a wolfberry raw material; the supercritical fluid extraction unit is connected with the cleaning device and comprises a fluid storage tank for storing an extracting agent; the supercritical extraction reaction tank permeates, dissolves and extracts nutritional ingredients of a medlar raw material such as medlar seeds, medlar fruits or a combination of the medlar seeds and the medlar fruits through supercritical fluid so as to obtain a primary extract; the temperature adjusting device is connected with the supercritical extraction reaction tank and is used for maintaining the temperature of the supercritical fluid; the pressure adjusting device is connected with the supercritical extraction reaction tank and is used for providing and maintaining the pressure of the supercritical fluid; the separating device is connected with the supercritical super-extraction reaction tank and is used for separating the primary extract; comprising a first circulating pump and a second circulating pump, the first circulating pump is used for returning the supercritical fluid to the supercritical fluid extraction unit, and the second circulating pump is used for returning residues to the supercritical fluid extraction unit.

Description

Technical Field

[0001] The present invention relates to an extraction system for extracting wolfberry pigment, and more specifically to a supercritical fluid extraction system for extracting wolfberry pigment without using solvent. Background Art

[0002] Supercritical carbon dioxide extraction (SCDE) is a highly efficient and advanced separation technology developed over decades in the chemical industry. The basic principle of SCDE is to dissolve the desired chemical components using a supercritical fluid at temperatures above the critical temperature and pressure. The pressure of the fluid solution is then reduced or the temperature is increased, causing the solute dissolved in the supercritical fluid to precipitate due to a decrease in density and solubility, thereby achieving the extraction of the specific solute. A supercritical fluid is a high-density fluid above its critical temperature and pressure. It is neither a gas nor a liquid, but rather possesses properties intermediate between those of gases and liquids, characterized by its excellent solvent properties. When in a supercritical state, the density of a fluid approaches that of a liquid and varies significantly with pressure and temperature. The solubility of solutes in a supercritical fluid increases with increasing density. SCDE technology can produce high-value-added products and extract substances that are inaccessible to chemical methods. It is cost-effective, safe, and efficient, making it ideally suited for use in the chemical, pharmaceutical, and food industries.

[0003] Literature reports indicate that wolfberry seed oil contains a significant amount of unsaturated fatty acids, including 68.3% linoleic acid, 2.8% gamma-linolenic acid, 19.1% oleic acid, and 271.4 μg / g vitamin E. Unsaturated fatty acids can lower cholesterol, prevent hyperlipidemia and arteriosclerosis, slow skin aging, nourish the skin, and whiten the skin. Furthermore, linoleic acid is beneficial for the growth and development of the heart, brain, and tissue cells in infants and young children. Therefore, wolfberry seed oil is an excellent health-promoting edible oil, effective in preventing and treating cardiovascular and cerebrovascular diseases, diabetes, hypertension, hyperlipidemia, and boosting the immune system in the elderly.

[0004] Traditional methods for extracting wolfberry seed oil generally use steam distillation, vacuum distillation, direct pressing, and organic solvent extraction to extract the active ingredients, which are then recovered through filtration, evaporation, or other separation methods. However, because wolfberry oil is a non-volatile oil that cannot be evaporated with water vapor, the yield of wolfberry oil when extracted using water distillation is low. Secondly, because wolfberry seeds are relatively hard, the oil yield is very low regardless of whether direct pressing methods such as cold pressing or hot pressing are used. Finally, when using solvent extraction methods such as water, ethanol, and methanol, the extracted wolfberry seed oil is of poor quality, low purity, and has an odor and solvent residue.

[0005] In order to improve the above-mentioned defects, supercritical CO2 fluid technology has been applied to the extraction of wolfberry seed oil. The supercritical CO2 extraction technology uses low-temperature extraction to promote its solubility in the substance to be separated by changing its density, and in the absence of pressure, to achieve the separation effect, the supercritical fluid will evaporate, and the amount of residual solvent is very small, or even no residue. For example,

[0006] In the literature such as "Research on Supercritical CO2 Extraction of Wolfberry Seed Oil", "Research on Supercritical CO2 Extraction of β-Carotene in Wolfberry Pigment", "Research on Supercritical CO2 Extraction of Wolfberry Oil", "Research on Supercritical CO2 Extraction of Wolfberry Oil" in Packaging and Food Machinery, "Research on Supercritical CO2 Extraction of Wolfberry Oil and Wolfberry Pigment (I)" and "Research on Supercritical CO2 Extraction of Wolfberry Oil and Wolfberry Pigment (II)" in Food Science and Technology, the methods of extracting wolfberry seed oil using supercritical CO2 were reported respectively, but the extraction rate and yield of wolfberry seed oil are still not ideal and need to be further improved.

[0007] In order to shorten the extraction time and further improve the yield, a supercritical carbon dioxide extraction of fruit seed oil and a product are disclosed in Chinese patent case CN1237618A, which involves using wolfberry seeds as raw materials, adjusting their moisture content to 13-18% (W) after screening and removing impurities, crushing them with a shearing mill and sieving them, controlling the particle size to 60-80 mesh and loading them into an extraction kettle, adjusting the pressure in the extraction kettle to 23-30 MPa and the temperature to 35-45°C for extraction, and adjusting the pressure and temperature after extraction to enter a separation kettle for separation. During separation, the separation is controlled. The separation temperature is between 28-36°C, and the separated oil is wolfberry seed oil. Testing shows it to be clear and transparent, with a normal flavor and odor, less than 0.5% impurities (W), an iodine value (gI2 / 100g oil) of 110-130, a saponification value (mgkOH / g oil) of 190-220, 1.2-1.3% phospholipids (W), 65-70% linoleic acid (W), 2-3% r-linolenic acid (W), 19-20% oleic acid (W), 6-7% palmitic acid (W), and 26-28 mg / 100g vitamin E. The separated carbon dioxide is liquefied, collected, pressure-regulated, and temperature-controlled before being returned to the extraction kettle for recycling. The residue in the extraction kettle can be used as a feed additive.

[0008] Furthermore, Chinese patent CN1272417C discloses a method for extracting wolfberry seed oil using a supercritical propane fluid. The method comprises: separating wolfberry seeds from fresh wolfberry berries, drying and crushing the seeds, and then placing them in a supercritical extraction kettle. A supercritical propane fluid at a flow rate of 3.0-7.0 kg / hr is introduced into the extraction kettle. After extraction for a certain period of time at a certain supercritical pressure and temperature (a pressure of 5-15 MPa, a temperature of 97-110° C., and an extraction time of 60-250 minutes), the wolfberry seed oil is separated in a desorption kettle at a pressure of 1.0-2.0 MPa and a temperature of 90-105° C., wherein the yield of the wolfberry seed oil is not less than 17%.

[0009] Although Chinese patents CN1237618A and CN1272417C claim to achieve short extraction times, high final product yields, and no propane residue, these prior art techniques still fail to overcome the challenges of extracting wolfberry pigments and the drawback of using solvents that damage the activity of the wolfberries. Furthermore, if the wolfberry fruit is directly subjected to a critical extraction system without solvent extraction, the polysaccharides rich in wolfberries can form blocks in the extraction kettle that are as hard as bricks and stones, leading to blockages in the fluid pipelines, deformation of the extraction kettle, and pressure increases exceeding the equipment's set limits. Consequently, if emergency measures are not implemented, these can easily lead to industrial accidents, resulting in equipment damage at best and casualties at worst.

[0010] Therefore, the industry is eager to develop a solvent-free supercritical fluid extraction system that can not only solve the problem of polysaccharide-induced clumping and pipeline blockage, but also address the difficulty of wolfberry pigment extraction, and can perform critical extraction efficiently without the use of solvents. Utility Model Content

[0011] To overcome the various defects and problems faced by the above-mentioned prior arts, the creators of the present invention have diligently researched various feasible solutions. As a result of numerous experiments and improvements, they have finally developed a solvent-free supercritical fluid extraction system. This system not only solves the problem of polysaccharides causing agglomeration and blockage of pipelines, but also solves the difficult problem of wolfberry pigment extraction. Moreover, it can efficiently perform critical extraction without the use of solvents, thereby obtaining wolfberry oil that is environmentally friendly, beneficial to health, rich in antioxidants, and has significantly increased nutritional content. This has completed the present invention.

[0012] Specifically, the present invention provides a solvent-free supercritical fluid extraction system suitable for low- to medium-temperature plant extraction with a high nutrient extraction rate. The system comprises a pre-treatment unit, a supercritical fluid extraction unit, a separation device, and a recovery unit.

[0013] Preferably, the pre-treatment unit includes a cleaning device for cleaning the wolfberry raw material and removing unnecessary impurities to obtain a plurality of clean wolfberry raw materials to be extracted.

[0014] Preferably, the supercritical fluid extraction unit is connected to the pre-treatment unit and comprises at least: a fluid storage tank for storing an extractant, a supercritical extraction reaction tank, a temperature adjustment device, and a pressure adjustment device.

[0015] According to the present invention, first, the extractant is pressurized by a pressure pump to form a supercritical fluid. In the supercritical extraction reaction tank, the supercritical fluid penetrates, dissolves, and extracts multiple nutrients from the raw material to be extracted, such as wolfberry seeds and fruits, to obtain a primary extract.

[0016] Preferably, the temperature adjustment device is connected to the supercritical extraction reaction tank to increase and maintain the temperature of the supercritical fluid above the critical point; the pressure adjustment device is connected to the supercritical extraction reaction tank to provide and maintain the pressure of the supercritical fluid above the critical point.

[0017] Preferably, the separation device is connected to the supercritical extraction reaction tank to guide the primary extract after supercritical extraction into the separation device to separate multiple wolfberry extracts, residues, and the supercritical fluid.

[0018] Preferably, the recovery unit includes at least a first circulation pump and a second circulation pump, the first circulation pump is used to return the supercritical fluid to the supercritical fluid extraction unit, and the second circulation pump is used to return the residue as a diluent to the supercritical fluid extraction unit.

[0019] Preferably, the temperature adjustment device includes a heater and a cooler, the heater is used to provide a heating function, and the cooler is used to provide a cooling function.

[0020] Preferably, the pressure regulating device includes a compressor and a pressure reducing valve, wherein the compressor is used to provide a pressurizing function, and the pressure reducing valve is used to provide a pressure reducing function.

[0021] Preferably, the separation device comprises a decompression chamber for passing the primary extract in a supercritical state through the decompression chamber to recover gaseous carbon dioxide and separate the plurality of wolfberry extracts and residues.

[0022] Preferably, the recovery unit further comprises a storage device for storing the residue in a suitable low-temperature environment.

[0023] Preferably, the system further includes a control unit, which is electrically connected to the supercritical fluid extraction unit, the temperature adjustment device and the pressure adjustment device, and is used to control the temperature, pressure and flow rate during the extraction process.

[0024] Preferably, the pre-processing unit further includes a drying device and a crushing device, the cleaning device is connected to the drying device, and the drying device is connected to the crushing device.

[0025] Preferably, the drying device is used to dry a plurality of wolfberry raw materials to reduce the moisture content.

[0026] Preferably, the crushing device is used to crush the dried wolfberry raw materials into uniform particles, thereby increasing the extraction area and improving the extraction efficiency.

[0027] Preferably, the nutritional components of wolfberry include flavonoids, polysaccharides, vitamins, minerals, fatty acids and carotenes.

[0028] Therefore, according to the solvent-free supercritical fluid extraction system provided by the utility model, wolfberry can be critically extracted in an anaerobic state using carbon dioxide as an extraction agent without using a solvent. In addition to successfully preventing the oxidation and denaturation of the extracted effective ingredients and effectively separating and removing pesticides and insecticides in the raw materials, wolfberry oil can also be obtained that is free of solvent residues and environmental pollution, is completely non-toxic, and has a significantly improved nutritional content. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of the solvent-free supercritical fluid extraction system of the present invention.

[0030] Figure 2 This is a schematic diagram of the configuration of the solvent-free supercritical fluid extraction system of the present invention.

[0031] Figure 3 This is a schematic structural diagram of the heater and cooler of the present invention.

[0032] Wherein: 1: solvent-free supercritical fluid extraction system; 10: pre-treatment unit; 11: cleaning device; 12: drying device; 13: crushing device; 20: supercritical fluid extraction unit; 21: fluid storage tank; 22: supercritical extraction reaction tank; 221: pressure pump; 23: temperature adjustment device; 231: heater; 232: cooler; 24: pressure adjustment device; 30: separation device; 31: decompression chamber; 40: recovery unit; 41: first circulation pump; 42: second circulation pump; 50: control unit; E0: primary extract; E f : Wolfberry extract.

[0033] The following is a detailed description of the preferred embodiments of the present invention in accordance with its purpose and efficacy. DETAILED DESCRIPTION

[0034] Below, different specific embodiments of the present invention are listed and described in more detail to make the spirit and content of the present invention more complete and easier to understand. However, those with ordinary knowledge in this art should understand that the present invention is certainly not limited to these examples, and other identical or equivalent functions and step sequences can also be used to implement the present invention.

[0035] In this article, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the field to which this invention belongs. In addition, unless the context clearly contradicts otherwise, singular terms used herein shall include pluralities, and plural terms shall include the singular.

[0036] See also Figure 1 and Figure 2 As shown, the utility model is a solvent-free supercritical fluid extraction system 1, which is characterized in that it is suitable for low-medium temperature extraction and plant extraction with high nutrient extraction rate. The system includes: a pre-treatment unit 10, a supercritical fluid extraction unit 20, a separation device 30, a recovery unit 40 and a control unit 50.

[0037] The pre-processing unit 10 includes a cleaning device 11, a drying device 12, and a crushing device 13. The cleaning device 11 is used to clean the wolfberry raw material and remove unnecessary impurities to obtain a plurality of clean wolfberry raw materials to be extracted. The cleaning device 11 is connected to the drying device 12, and the drying device 12 is connected to the crushing device 13. In the present invention, the wolfberry raw material can be wolfberry seeds or wolfberry fruits; or it can be at least one of wolfberry seeds, wolfberry fruits, or a combination thereof.

[0038] The drying device 12 is used to dry the wolfberry raw materials to reduce the moisture content. The crushing device 13 is used to crush the dried wolfberry raw materials into granular powder to increase the extraction area and improve the extraction efficiency.

[0039] Furthermore, in the supercritical extraction system of the present invention, suitable pulverization methods for wolfberry raw materials include, for example, at least one of pounding, mechanical crushing, shock crushing, ultrasonic crushing, coarse crushing, fine crushing, and combinations thereof.

[0040] In addition, in the supercritical extraction system of the present invention, the size of the granular powder is not particularly limited, and the particle size is usually controlled to be above No. 50 mesh or below No. 100 mesh.

[0041] In one embodiment, the supercritical fluid extraction unit 20 is connected to the pre-treatment unit, and the supercritical fluid extraction unit 20 includes at least: a fluid storage tank 21, a supercritical extraction reaction tank 22, a temperature adjustment device 23, and a pressure adjustment device 24; wherein the fluid storage tank 21 is used to store an extraction agent.

[0042] Furthermore, suitable extractants for use in the supercritical extraction of the present invention include, for example, carbon dioxide (CO2), nitrous oxide, sulfur hexafluoride, ethane, methanol, ammonia, water, and at least one of their combinations. Among those extractants, carbon dioxide (CO2) has a critical temperature (31°C) close to room temperature, a low liquefaction pressure, and a moderate critical pressure (7.31MPa), making it easy to reach a supercritical state and less damaging to volatile or physiologically active substances; it is also safe and non-toxic, and can easily complete extraction and separation in one go, without residue, making it very suitable for extracting food, natural medicine, plants, and the like using a supercritical extraction method. Therefore, in the present invention, carbon dioxide (CO2) is preferably used as an extractant for supercritical extraction.

[0043] In one embodiment, the supercritical extraction reaction tank 22 pressurizes the extractant via a pressure pump 221 to form a supercritical fluid. The supercritical fluid penetrates, dissolves, and extracts nutrients from multiple wolfberry raw materials to be extracted, such as wolfberry seeds, wolfberry fruits, or a combination thereof, to obtain a primary extract E0.

[0044] In the present invention, the number of supercritical extraction reaction tanks 22 is not particularly limited. For example, there may be one, two, or more supercritical extraction reaction tanks. When multiple supercritical extraction reaction tanks 22 are used, the multiple extraction reaction tanks may be connected in series or in parallel. In the present invention, it is preferred to use one extraction reaction tank or multiple extraction reaction tanks connected in series.

[0045] In one embodiment, the temperature adjustment device 23 is connected to the supercritical extraction reaction tank 22 to increase and maintain the temperature of the supercritical fluid above the critical point; the pressure adjustment device 24 is connected to the supercritical extraction reaction tank 22 to provide and maintain the pressure of the supercritical fluid above the critical point.

[0046] In the present invention, the upper and lower limits of the temperature adjustment of the temperature adjustment device 23 are usually between 190°K and 700°K; as long as the density of the supercritical fluid can be adjusted to 100-1000 (kg / m3 ), the diffusion coefficient is adjusted within the range of 0.01-0.1 (mm2 / s), and the viscosity is adjusted within the range of 50-100 (μPa·s), without any particular limitation. In one embodiment, the separation device 30 is connected to the supercritical extraction reaction tank 22 to guide the primary extract after supercritical extraction into the separation device 30 to separate a plurality of wolfberry extracts E f , residue, and the supercritical fluid.

[0047] In the present invention, the separation device 30 is only required to be able to effectively separate the wolfberry extract E f , residue, and supercritical fluid, without particular limitation; for example, it is usually at least one of a filter, a screener, a vacuum separator, a low-pressure separator, a medium-pressure separator, a high-pressure separator, and a gravity pressure separator.

[0048] In one embodiment, the recovery unit 40 includes at least a first circulation pump 41, a second circulation pump 42 and a storage device 43. The first circulation pump 41 is used to return the supercritical fluid to the supercritical fluid extraction unit 20, and the second circulation pump 42 is used to return the residue as a diluent to the supercritical fluid extraction unit 20.

[0049] In the present invention, there is no particular limitation on the number of the first circulation pump 41 and the second circulation pump 42. For example, there can be one, two, or more first circulation pumps 41 and the second circulation pump 42. When a plurality of first circulation pumps 41 and the second circulation pump 42 are used, the plurality of first circulation pumps 41 and the second circulation pump 42 can be connected in series or in parallel.

[0050] In one embodiment, the storage device 43 is used to store the residue in a suitable low-temperature environment. The residue after the wolfberry raw material is extracted is properly stored at a temperature between 0°C and room temperature. The residue is a diluent. The wolfberry raw material is extracted in an appropriate proportion, and the final product can be extracted without using a solvent, and there is no need to destroy the effective ingredients during the solvent removal process.

[0051] In one embodiment, the control unit 50 is electrically connected to the supercritical fluid extraction unit 20 , the temperature adjustment device 23 , and the pressure adjustment device 24 . The control unit 50 is used to control the temperature, pressure, and flow rate during the extraction process.

[0052] like Figure 2As shown, the pressure regulating device 24 includes a compressor 241 and a pressure reducing valve 242, wherein the compressor is used to provide a pressurizing function, and the pressure reducing valve is used to provide a pressure reducing function. Furthermore, the main function of the compressor 241 in the supercritical extraction reaction tank 22 is to increase the pressure of the extractant so that it reaches or exceeds the supercritical state. The characteristics of supercritical fluids (such as supercritical carbon dioxide) are particularly significant under high pressure, so the compressor 241 is the core component that ensures that the supercritical extraction reaction tank 22 can perform supercritical extraction.

[0053] In the present invention, the upper and lower limits of the pressure adjustment of the pressure adjustment device 24 are generally between 30 atmospheres and 300 atmospheres; as long as the density of the supercritical fluid can be adjusted to 100-1000 (kg / m 3 ), the diffusion coefficient is adjusted within the range of 0.01-0.1 (mm2 / s), and the viscosity is adjusted within the range of 50-100 (μPa·s), without any particular limitation.

[0054] In one embodiment, the specific functions of the compressor 241 include: raising the carbon dioxide pressure from a lower pressure to the high pressure required for the supercritical state (usually above 7.38 MPa); circulating the extractant through the different components of the solvent-free supercritical fluid extraction system 1, including the supercritical extraction reaction tank 22 and the separation device 30, to ensure continuous flow and uniform distribution of the fluid; ensuring that the solvent-free supercritical fluid extraction system 1 maintains a constant supercritical pressure throughout the extraction process, thereby optimizing the extraction efficiency and effect.

[0055] Furthermore, the function of the pressure reducing valve 242 in the solvent-free supercritical fluid extraction system 1 is to control and reduce the pressure of the fluid, returning it from the supercritical state to a lower pressure, which is crucial for separating and extracting the active ingredients and for the safe operation of the system.

[0056] In one embodiment, the specific functions of the pressure reducing valve 242 include: reducing the pressure of the high-pressure extractant to a lower pressure, changing the extractant from a supercritical state to a subcritical or gaseous state, thereby achieving precipitation or separation of the active ingredients; controlling the flow and pressure of the extractant by adjusting the valve opening to ensure a smooth and controllable extraction process; and when the pressure of the solvent-free supercritical fluid extraction system 1 is too high, the pressure reducing valve 242 can prevent the system from overloading or causing dangerous situations, thereby playing a protective role.

[0057] In addition, the pressure reducing valve 242 suitable for use in the present invention is not particularly limited to which type is used. For example, any one or more of a direct-acting pressure reducing valve, an auxiliary valve type pressure reducing valve, a constant pressure load type pressure reducing valve, and a variable pressure load type pressure reducing valve can be used.

[0058] like Figure 3 As shown, the temperature adjustment device 23 includes a heater 231 and a cooler 232. The heater 231 is used to provide heating, and the cooler 232 is used to provide cooling. Specifically, the heater 231 has the following functions: heating the extractant to the required temperature for the supercritical state. For example, the supercritical temperature of carbon dioxide is 31.1°C, so the heater 231 must ensure that the temperature is above this value; maintaining a constant temperature during the extraction process to ensure stability and controllability of the extraction process; and high temperature helps to improve the solubility of the extractant, thereby more effectively extracting the target component.

[0059] In the present invention, the upper and lower limits of the temperature adjustment of the heater 231 are as long as the density of the supercritical fluid can be adjusted to 100-1000 (kg / m 3 ), the diffusion coefficient is adjusted within the range of 0.01–0.1 (mm² / s), and the viscosity is adjusted within the range of 50–100 (μPa·s), without particular limitation. Furthermore, the type of heater 231 that can be used is not particularly limited; for example, any one or more of a resistive heater, a coil heater, an electromagnetic heater, and an infrared heater can be used.

[0060] Secondly, the specific functions of the cooler 232 include: cooling the extractant from the supercritical state to a lower temperature to facilitate the precipitation or precipitation of the active ingredients; adjusting the temperature of the fluid through the cooler at different stages of the system to achieve the best separation effect; and preventing high temperature from damaging other equipment in the solvent-free supercritical fluid extraction system 1, thereby extending the service life of the equipment.

[0061] In the present invention, the upper and lower limits of the temperature adjustment of the cooler 232 are generally between -20°C and 50°C, without particular limitation. Furthermore, the cooler 232 is not particularly limited in type. For example, any one or more of a shell-and-tube cooler, a plate cooler, an air-cooled cooler, a double-tube cooler, a vertical cooler, a horizontal cooler, an indirect cooler, a fixed cooler, and a suspended cooler may be used.

[0062] In one embodiment, the solvent-free supercritical fluid extraction system 1 of the present invention can be used to effectively extract various nutrients from wolfberry, for example, wolfberry oil including flavonoids, polysaccharides, vitamins, minerals, fatty acids and carotene can be extracted.

[0063] Goji berries are rich in flavonoids, such as lutein. According to literature and research reports, lutein is a powerful antioxidant with antioxidant and anti-inflammatory effects that helps protect eye health.

[0064] Secondly, wolfberry also contains main active ingredients such as polysaccharides, which have multiple physiological activities such as immune regulation, anti-fatigue, and anti-aging. The specific content will be affected by the plant variety, growth environment and extraction method.

[0065] Furthermore, wolfberry is also rich in vitamins, such as vitamin C and vitamin E, which help to enhance the immune system and antioxidant capacity, and help protect cell membranes from oxidative damage.

[0066] In addition, wolfberry is also rich in minerals or important trace elements such as zinc and copper, which play an important role in various metabolic processes and enzyme systems of the human body and are beneficial to human health.

[0067] Goji berries are also rich in fatty acids, primarily polyunsaturated fatty acids such as linolenic acid and linolenic acid, which are beneficial for cardiovascular health. The specific content of polyunsaturated fatty acids in goji berries varies depending on the goji berry variety and extraction method.

[0068] Furthermore, the main component of carotene compounds in wolfberry is β-carotene and other similar carotene compounds, which can be effectively extracted under supercritical CO2. The choice of temperature and pressure usually affects the efficiency and yield of extraction.

[0069] In one embodiment, the present invention utilizes a solvent-free supercritical fluid extraction system to extract wolfberry oil, rich in unsaturated fatty acids such as linoleic acid and linolenic acid, from both wolfberry seeds and berries. The total oil content in the wolfberry oil typically ranges from 3.5% to 35%. Furthermore, in actual extraction processes, problems such as excessive polysaccharide concentrations causing clumping, pipe blockage, and vessel deformation have never occurred. Furthermore, the wolfberry oil extraction process has been able to be performed effectively and without the use of solvents for at least 700 working days.

[0070] Therefore, the solvent-free supercritical fluid extraction system of the present invention can achieve at least the following excellent effects:

[0071] 1. Since wolfberry is extracted under critical state, it can effectively solve the problem of wolfberry pigment being difficult to extract;

[0072] 2. Since the critical extraction of wolfberry is carried out in the absence of solvent, there is no need for a solvent storage tank, nor is there any need to heat the solvent to remove it, so there is no problem of solvent residue. 3. Since the critical extraction of wolfberry is carried out at a temperature below 35°C, the activity of the wolfberry can be fully retained.

[0073] 4. Since the residue after extraction is used as a diluent, there will be no problems such as pipeline blockage and extraction kettle deformation caused by excessive polysaccharide concentration forming lumps.

[0074] In summary, the contents of this utility model have been illustrated by the above embodiments. However, this utility model is not limited to these embodiments. Those skilled in the art of the present utility model may make various changes and modifications without departing from the spirit and scope of this utility model. For example, the various technical contents illustrated in the above embodiments may be combined or modified to form new embodiments, and such embodiments are naturally considered to be within the scope of this utility model. Therefore, the scope of protection sought in this case also includes the claims and the scope defined therein.

Claims

1. A solvent-free supercritical fluid extraction system, characterized in that: Suitable for low to medium temperature extraction and high nutrient extraction rate of plant extraction, the system includes: a pre-treatment unit comprising a cleaning device for cleaning the wolfberry raw material and removing unnecessary impurities to obtain a plurality of clean wolfberry raw materials to be extracted; A supercritical fluid extraction unit, connected to the pre-treatment unit, comprising at least: a fluid storage tank for storing an extractant; a supercritical extraction reaction tank, wherein the extractant is pressurized by a pressure pump to form a supercritical fluid, and the supercritical fluid penetrates, dissolves and extracts the plurality of nutrients of the wolfberry raw material to be extracted to obtain a primary extract; a temperature adjustment device connected to the supercritical extraction reaction tank, for raising and maintaining the temperature of the supercritical fluid above the critical point; a pressure regulating device connected to the supercritical extraction reaction tank to provide and maintain the pressure of the supercritical fluid above the critical point; a separation device connected to the supercritical extraction reaction tank, for guiding a primary extract after supercritical extraction into the separation device to separate a plurality of wolfberry extracts, residues, and the supercritical fluid; and A recovery unit includes at least a first circulation pump and a second circulation pump, wherein the first circulation pump is used to return the supercritical fluid to the supercritical fluid extraction unit, and the second circulation pump is used to return the residue as a diluent to the supercritical fluid extraction unit.

2. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The temperature adjustment device includes a heater and a cooler. The heater is used to provide a heating function, and the cooler is used to provide a cooling function.

3. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The pressure regulating device includes a compressor and a pressure reducing valve. The compressor is used to provide a pressure increasing function, and the pressure reducing valve is used to provide a pressure reducing function.

4. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The separation device includes a decompression chamber for passing the primary extract in a supercritical state through the decompression chamber to recover gaseous carbon dioxide and separate a plurality of wolfberry extracts and residues.

5. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The recovery unit further comprises a storage device for storing the residue in a suitable low temperature environment.

6. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The system further includes a control unit electrically connected to the supercritical fluid extraction unit, the temperature adjustment device, and the pressure adjustment device. The control unit is used to control the temperature, pressure, and flow rate during the extraction process.

7. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The pre-processing unit further includes a drying device and a crushing device. The cleaning device is connected to the drying device, and the drying device is connected to the crushing device.

8. The solvent-free supercritical fluid extraction system according to claim 7, characterized in that: The drying device is used for drying a plurality of wolfberry raw materials to reduce the moisture content.

9. The solvent-free supercritical fluid extraction system according to claim 7, characterized in that: The crushing device is used to crush the dried wolfberry raw materials into uniform particles, thereby increasing the extraction area and improving the extraction efficiency.

10. The solvent-free supercritical fluid extraction system according to claim 1, characterized in that: The nutritional components of wolfberry include flavonoids, polysaccharides, vitamins, minerals, fatty acids and carotenes.

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