Extraction method for rhodiola rosea extract

Abstract

The invention discloses an extraction method for a rhodiola rosea extract, and relates to the technical field of traditional Chinese medicine extraction. The extraction method for the rhodiola rosea extract comprises the following steps: carrying out steam explosion and composite enzymatic hydrolysis pretreatment on a rhodiola rosea raw material, and then carrying out gradient reflux extraction by using a 70% ethanol solution; carrying out low-temperature cold precipitation treatment on the extracting solution at 0-4 DEG C, and carrying out filter pressing in combination with a filter aid to obtain clear filtrate; and concentrating the filtrate under reduced pressure until the specific gravity is 1.04-1.06, immediately introducing high-shear homogenization treatment, and finally performing spray drying. The core of the invention lies in that a specific gravity 1.05 node coupling homogenization technology is utilized, so that the rheological property of the feed liquid is obviously improved, and the industrial problems that the rhodiola rosea extract is easy to stick to the wall and block a gun during spray drying are thoroughly solved. Meanwhile, low-temperature cold precipitation is adopted to replace traditional macroporous resin purification, ineffective viscous impurities are effectively removed, and meanwhile, full-spectrum active ingredients such as salidroside, polysaccharide and flavone are reserved to the maximum extent.

Description

Technical Field

[0001] This invention relates to the field of traditional Chinese medicine extraction technology, and in particular to a method for extracting Rhodiola rosea extract. Background Technology

[0002] Rhodiola rosea, a precious plant used in both medicine and food, is rich in various active ingredients such as rhodioloside, tyrosol, and rhodioloside. It has significant pharmacological effects such as anti-fatigue, anti-hypoxia, anti-microwave radiation, and anti-aging, and is widely used in pharmaceutical preparations, functional foods, and cosmetic raw materials. With the development of the health industry, the market demand for Rhodiola rosea extract is increasing, especially for standardized extracts that can retain the full spectrum of plant activity and have excellent physical properties (such as good solubility and uniform color). At present, the main methods for extracting active ingredients such as rhodioloside in industry include solvent extraction, microwave-assisted extraction, and ultrasonic extraction. Among them, ethanol reflux extraction is the mainstream method in large-scale industrial production due to its mature technology and the recyclability of solvents.

[0003] A search revealed that existing methods for extracting rhodioloside and rhodioloside from Rhodiola rosea generally involve: pulverizing Rhodiola rosea rhizomes and refluxing them with an ethanol-water solution; filtering and concentrating the extract under reduced pressure; passing the extract through a pre-treated macroporous adsorption resin column; eluting with gradients of ethanol at different concentrations; and finally collecting and drying the eluent to obtain the extract. While this method improves the purity of specific monomeric components through resin purification, representing a typical technical route for pursuing high-purity monomers, its complex column chromatography and elution processes significantly extend the production cycle. Furthermore, the resin regeneration process generates a large amount of acidic and alkaline wastewater, which is inconsistent with the trend of green manufacturing.

[0004] However, the aforementioned existing technologies still have significant drawbacks in practical industrial applications. First, while over-reliance on macroporous resin purification increases the content of indicator components, it often filters out coexisting components in Rhodiola rosea, such as polysaccharides and flavonoids, which have synergistic effects, causing the extract to lose its "full-spectrum" efficacy. Moreover, the risk of resin residue remains a concern in the food and cosmetics industries. Second, in conventional ethanol extraction-spray drying processes, most technical solutions neglect the control of rheological properties during the concentration of the extract and often fail to precisely limit the specific gravity of the liquid before it enters the tower. This often leads to problems such as liquid sticking to the walls, nozzle clogging, or high hygroscopicity and uneven bulk density of the finished powder during the spray drying stage. In addition, if single-concentration ethanol extraction is not optimized in terms of the number of refluxes and solvent usage, it is difficult to achieve the best balance between extraction efficiency and energy consumption, resulting in high production costs. Summary of the Invention

[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, the present invention aims to provide an extraction method for Rhodiola rosea extract. This invention seeks to solve the technical problems in existing Rhodiola rosea extraction processes, such as the loss of full-spectrum co-active components due to macroporous resin purification, the tendency for conventional spray drying to easily cause material adhesion to the walls and nozzle blockage due to improper control of the rheological properties of the extract, and the low extraction efficiency caused by a single extraction mode.

[0006] (II) Technical Solution To address the aforementioned technical problems, this invention provides a method for extracting Rhodiola rosea extract, which specifically includes the following steps: Step (1) Preprocessing: Rhodiola rosea raw material is crushed and then subjected to cell wall breaking treatment to obtain pretreated material.

[0007] As a preferred embodiment of the present invention, the specific process of the cell wall breaking treatment is as follows: Rhodiola rosea raw material pulverized to 20 mesh is moistened with 10% purified water by weight of the raw material, and then subjected to steam explosion treatment at a pressure of 0.1 MPa for 30 seconds; after the pressure is released, the material is cooled to 45°C, and a compound enzyme preparation is added for enzymatic hydrolysis for 30 minutes; wherein, the compound enzyme preparation is composed of cellulase and pectinase.

[0008] Step (2) Extraction: The pretreated material was subjected to multiple reflux extractions using a 65% ethanol solution, and the extracts were combined.

[0009] As a preferred embodiment of the present invention, the specific process of the reflux extraction is as follows: three gradient reflux extractions are performed using a 70% ethanol solution. Specifically, the first extraction is performed by adding an ethanol solution with a weight of 8 times that of the raw material and refluxing for 2 hours; the second extraction is performed by adding an ethanol solution with a weight of 6 times that of the raw material and refluxing for 1.5 hours; and the third extraction is performed by adding an ethanol solution with a weight of 4 times that of the raw material and refluxing for 1 hour.

[0010] Step (3) Cold settling to remove impurities: The extract was cooled to 0°C and allowed to settle. The mixture was then filtered to obtain a clear filtrate.

[0011] As a preferred embodiment of the present invention, the specific process of cold precipitation and impurity removal is as follows: the combined extract is rapidly cooled to 4°C, kept at the temperature and allowed to settle for 12-24 hours for winterization treatment; after obvious flocculent precipitate appears in the solution, 0.5%-1% of filter aid is added for plate and frame filtration, and the clear filtrate is collected; the filter aid is at least one of diatomaceous earth or perlite.

[0012] Step (4) Concentration and Homogenization: The clarified filtrate was concentrated under reduced pressure. When the specific gravity of the concentrate reached 1.04, the concentration was stopped, and the concentrate was immediately subjected to high-shear homogenization to obtain a homogenized liquid.

[0013] As a preferred embodiment of the present invention, the operating conditions for vacuum concentration are: vacuum degree -0.07MPa to -0.09MPa, concentration temperature ≤60℃.

[0014] Preferably, the specific gravity of the concentrate (measured at 50°C) is precisely controlled to be 1.05±0.005, and homogenization is carried out at this critical specific gravity.

[0015] Preferably, the operating parameters of the high-shear homogenization process are: homogenization speed of 3000 rpm and homogenization time of 5-10 minutes, so that the concentrate forms a uniform microemulsion system.

[0016] Step (5) Spray drying: The homogenized liquid was spray-dried to obtain Rhodiola rosea extract.

[0017] As a preferred embodiment of the present invention, the spray drying adopts a centrifugal spray drying tower, and its operating parameters are: the inlet air temperature is controlled at 155℃, the outlet air temperature is controlled at 85℃, and the atomizer speed is 20000-24000rpm.

[0018] In addition, the present invention also provides a Rhodiola rosea extract prepared by any of the above methods, wherein the extract contains ≥1% rhodioloside by mass and ≥5% Rhodiola rosea polysaccharide by mass, and the extract retains the full spectrum of active ingredients of Rhodiola rosea and has the appearance of a brownish-red to light brownish-red powder.

[0019] This invention also provides the application of the above-mentioned Rhodiola rosea extract in the preparation of pharmaceutical, functional food, or cosmetic raw materials for anti-fatigue, anti-hypoxia, or immune-enhancing purposes.

[0020] Compared with the prior art, the beneficial effects of the present invention are: This invention replaces the traditional macroporous resin adsorption purification process with a low-temperature cold precipitation coupled physical filtration technology, effectively solving the problem of loss of co-existing components such as Rhodiola rosea polysaccharides and flavonoids caused by resin adsorption in the prior art. This improvement ensures that the obtained extract has complete full-spectrum activity and can fully exert the synergistic pharmacological effects of multiple components of traditional Chinese medicine. Since the entire process does not require the use of acid or alkali for resin regeneration, the hidden dangers of organic solvent and chemical reagent residues are eliminated from the source, significantly improving the safety of the product in the fields of food, health products and cosmetics, and truly achieving the process goal of "derived from nature" and complete components.

[0021] Addressing the industry pain point that Rhodiola rosea extract is prone to sticking to the spray drying wall and clogging the nozzle during the spray drying stage, this invention introduces a high-shear homogenization process at the critical point when the concentrate reaches a critical specific gravity of 1.05, which thoroughly improves the properties of the liquid from a physical rheological perspective. The high shear effect effectively breaks down the micro-macromolecules formed by high-concentration solutes, reduces the surface tension and cohesion of the liquid, and makes the droplet distribution more uniform during atomization. This design solves the problems of low powder collection rate and easy moisture absorption and agglomeration of the finished powder caused by uncontrolled viscosity of the liquid in the background technology, significantly reduces the frequency of downtime cleaning in industrial production, and obtains standardized extract powder with excellent flowability and stable properties.

[0022] Furthermore, this invention introduces a pretreatment method combining steam explosion and enzymatic hydrolysis, which breaks down the dense lignified structure of Rhodiola rosea rhizomes, significantly improving the penetration efficiency of 70% ethanol and the dissolution rate of active ingredients. This significantly shortens the extraction cycle while reducing solvent energy consumption. Because the heat-sensitive colloidal impurities that cause sticking to the wall are removed in advance through a cold precipitation process, the spray drying process can be completed at a gentler inlet air temperature, effectively avoiding thermal degradation and color charring of core active ingredients such as rhodioloside. The final product has a bright color, and the yields of rhodioloside and polysaccharides are both at a high level, achieving a highly efficient balance between production cost, process efficiency, and product quality. Attached Figure Description

[0023] The invention will be further described below with reference to the accompanying drawings: Figure 1 This is a flowchart of the full-spectrum Rhodiola rosea extraction process of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0025] Example 1: This embodiment provides a method for extracting Rhodiola rosea extract, the specific steps of which are as follows: 1) Pretreatment: Take 100kg of dried Rhodiola rosea rhizome raw material and crush it to 30 mesh. Add 12kg of purified water to moisten it, and send it into a steam explosion device. Maintain a pressure of 0.15MPa for 45 seconds and then release the pressure instantly. After the material cools down to 48℃, add 0.2kg of compound enzyme (cellulase and pectinase in a 1:1 mass ratio) and incubate for 45 minutes for enzymatic hydrolysis.

[0026] 2) Extraction: First extraction: Add 900 kg (9 times the volume) of 70% ethanol solution and reflux for 2 hours; Second extraction: Add 700 kg (7 times the amount) of 70% ethanol solution and reflux for 1.5 hours; Third extraction: Add 500 kg (5 times the amount) of 70% ethanol solution and reflux for 1 hour.

[0027] Combine the extracts and filter out the residue.

[0028] 3) Cold sedimentation and impurity removal: The combined extract is rapidly cooled to 2°C through a plate heat exchanger and sent to an insulated tank for settling for 18 hours. After obvious colloidal precipitate appears at the bottom of the tank, 0.8 kg of diatomaceous earth is added as a filter aid, and the mixture is filtered through a plate and frame filter press. The filter residue is discarded and the clear filtrate is collected.

[0029] 4) Concentration and Homogenization: The filtrate is concentrated under reduced pressure at a vacuum of -0.08 MPa and a temperature of 55°C. The specific gravity of the concentrate is monitored in real time, and concentration is stopped immediately when the specific gravity reaches 1.050 at 50°C. The concentrate is then pumped into a high-shear emulsification tank and homogenized at 4000 rpm for 8 minutes to form a uniform dispersion system.

[0030] 5) Spray drying: A centrifugal spray dryer is used, with the inlet air temperature set at 160℃, the outlet air temperature at 80℃, and the atomizer speed at 22000 rpm. After spraying, the powder is collected and pulverized through an 80-mesh sieve.

[0031] Example 2: This embodiment provides a method for extracting Rhodiola rosea extract, the specific steps of which are as follows: 1) Pretreatment: Same as in Example 1, except the pressure is adjusted to 0.2 MPa, steam explosion for 60 seconds, and enzymatic hydrolysis for 60 minutes.

[0032] 2) Extraction: The sample was extracted three times by reflux with 75% ethanol solution. The first extraction used 10 times the amount of ethanol, the second used 8 times the amount of ethanol, and the third used 6 times the amount of ethanol. The extraction times were 2 hours, 1.5 hours, and 1 hour, respectively.

[0033] 3) Cold settling to remove impurities: Cool to 4°C, let stand and settle for 24 hours, then add 1% perlite to aid filtration.

[0034] 4) Concentration and homogenization: Concentrate under reduced pressure to a specific gravity of 1.060, and homogenize at 5000 rpm for 10 minutes.

[0035] 5) Spray drying: inlet air temperature 165℃, outlet air temperature 85℃, atomizer speed 24000rpm.

[0036] Comparative Example 1: This comparative ratio does not undergo cold settling or homogenization treatment; specifically: Take 100 kg of the same Rhodiola rosea raw material, directly extract it three times by reflux with 70% ethanol, combine the extracts, filter them, concentrate them under reduced pressure to a specific gravity of 1.050, without homogenization, and spray dry them directly according to the parameters of Example 1.

[0037] Comparison of experimental results The Rhodiola rosea extracts obtained in the above examples and comparative examples were tested, and the results are shown in Table 1: Table 1 Comparison of Process Parameters and Product Quality for Each Group Results analysis: Anti-sticking effect: Comparing Example 1 and Comparative Example 1, it can be seen that under the same specific gravity (1.05), the liquid treated by "high shear homogenization" did not stick to the wall during spray drying, while Comparative Example 1, due to the lack of change in the rheological properties of the liquid, resulted in severe sticking and nozzle blockage, and the yield dropped significantly.

[0038] Integrity of components: The polysaccharide content of Example 1 was significantly higher than that of Comparative Example 1. This is because the present application precisely removed plant wax and long-chain impurities through "cold precipitation", while Comparative Example 1 did not perform effective impurity removal, resulting in uneven heating or encapsulation of active ingredients during the drying process. In addition, traditional processes usually pass through resin columns, resulting in a large loss of polysaccharides.

[0039] Physicochemical properties: The extracts prepared in the embodiments of this application are superior to those of the comparative examples in terms of solubility and appearance, which proves the superiority of the coupling process.

[0040] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for extracting Rhodiola rosea extract, characterized in that, Includes the following steps: (1) Pretreatment: Rhodiola rosea raw material is crushed and then subjected to cell wall breaking treatment to obtain pretreated material; (2) Extraction: The pretreated material was subjected to multiple reflux extractions using a 65% ethanol solution, and the extracts were combined; (3) Cold precipitation to remove impurities: The extract is cooled to 4°C and allowed to settle, then filtered to obtain a clear filtrate; (4) Concentration and homogenization: The clarified filtrate is concentrated under reduced pressure. When the specific gravity of the concentrate reaches 1.04-1.06, the concentration is stopped and the concentrate is immediately subjected to high shear homogenization to obtain a homogenized liquid. (5) Spray drying: The homogenized liquid is spray dried to obtain Rhodiola rosea extract.

2. The method for extracting Rhodiola rosea extract according to claim 1, characterized in that, The specific process of cell wall breaking treatment in step (1) is as follows: Add 10%-15% of purified water by weight of the Rhodiola rosea raw material crushed to 20-40 mesh to wet it, and perform steam explosion treatment at 0.1-0.2 MPa pressure for 30-60 seconds; after the pressure is released, cool it to 45-50℃, add compound enzyme preparation for enzymatic hydrolysis for 30-60 minutes. The compound enzyme preparation is composed of cellulase and pectinase.

3. The method for extracting Rhodiola rosea extract according to claim 1, characterized in that, The specific process of reflux extraction in step (2) is as follows: Extraction was performed three times by reflux with 70% ethanol solution. First extraction: Add 8-10 times the weight of the raw material in ethanol solution and reflux for 2 hours; Second extraction: Add 6-8 times the weight of the raw material in ethanol solution and reflux for 1.5 hours. Third extraction: Add 4-6 times the weight of the raw material in ethanol solution and reflux for 1 hour.

4. The method for extracting Rhodiola rosea extract according to claim 1, characterized in that, The specific process of cold precipitation and impurity removal in step (3) is as follows: The extract was rapidly cooled to 0-4℃ and kept at that temperature for 12-24 hours to allow it to settle. After flocculent precipitate appeared in the solution, 0.5%-1% of filter aid was added for pressure filtration, and the filtrate was collected. The filter aid is at least one of diatomaceous earth or perlite.

5. The method for extracting Rhodiola rosea extract according to claim 1, characterized in that, In step (4), the conditions for vacuum concentration are: vacuum degree -0.07MPa~-0.09MPa, concentration temperature ≤60℃.

6. The method for extracting Rhodiola rosea extract according to claim 1, characterized in that, In step (4), the specific gravity of the concentrate is controlled to be 1.05 ± 0.

005.

7. A method for extracting Rhodiola rosea extract according to claim 1 or 6, characterized in that, In step (4), the parameters for the high-shear homogenization process are: homogenization speed 3000-5000 rpm, homogenization time 5-10 minutes.

8. The method for extracting Rhodiola rosea extract according to claim 1, characterized in that, The parameters for spray drying in step (5) are: inlet air temperature 155-165℃, outlet air temperature 75-85℃, and atomizer speed 20000-24000rpm.

9. The Rhodiola rosea extract prepared according to any one of claims 1-8, characterized in that, The extract contains ≥1% rhodioloside and ≥5% rhodiola polysaccharide, and is a full-spectrum extract of rhodiola.

10. The use of the Rhodiola rosea extract according to claim 9 in the preparation of drugs, functional foods or cosmetics for anti-fatigue, anti-hypoxia or immune enhancement.

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