A method for preparing an extract of ginseng with reduced soil taste by using multi-stage membrane separation
By using multi-stage membrane separation technology to remove the earthy odor components from ginseng extract step by step, the problem of poor deodorization effect and loss of effective ingredients in existing technologies is solved, achieving a highly efficient and widely applicable deodorization effect, suitable for the industrial application of ginseng extracts from different sources.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHENGZHOU TOBACCO RES INST OF CNTC
- Filing Date
- 2026-04-27
- Publication Date
- 2026-06-09
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of ginseng deep processing technology, specifically relating to a method for preparing an extract that significantly reduces the earthy taste of ginseng using multi-stage membrane separation. Background Technology
[0002] Ginseng, a plant belonging to the genus Panax in the family Araliaceae, is a traditional and precious Chinese medicinal herb, as well as an important natural fragrance ingredient. Its extracts contain a variety of effective components such as ginsenosides, polysaccharides, and amino acids, and have unique aroma and nutritional and health benefits. It is widely used in the fields of cigarettes, food, and health products.
[0003] Ginseng typically grows in well-drained, loose, fertile soil with a deep humus layer. During its growth, it absorbs humus and geosmin from the soil, resulting in ginseng extracts often having a pronounced earthy (searthy) flavor. This earthy flavor is mainly composed of small-molecule impurities derived from soil humus and off-flavor compounds such as geosmin (including 2-isopropyl-3-methoxypyrazine, 3-isopropyl-2-methoxy-5-methylpyrazine, 2-sec-butyl-3-methoxypyrazine, and 3-sec-butyl-2-methoxy-5-methylpyrazine). This significantly affects the sensory quality of ginseng extracts, especially in cigarette flavoring applications, where it interferes with the cigarette aroma, reduces the cigarette's fragrance and smoothness, produces off-flavors, and negatively impacts the consumer experience.
[0004] Currently, existing technologies for deodorizing ginseng extracts mainly include solvent extraction and activated carbon adsorption. However, these methods have significant drawbacks: solvent extraction easily leads to the loss of ginseng's effective components and may introduce new solvent residues; activated carbon adsorption has poor selectivity, and while adsorbing odor components, it also adsorbs a large amount of core effective components such as ginsenosides. Existing literature ("Separation, Purification and Biotransformation of Ginsenosides in Ginseng Buds [D]", Beijing: Beijing University of Chemical Technology, 2010; "Adsorption Effect of Activated Carbon on Ginsenoside Re in Shengmai Injection [J]", Journal of Traditional Chinese Medicine, 2002, 16(5): 23-24.) suggests that activated carbon adsorption is more suitable for macromolecular polysaccharides, amino acids, and proteins; however, it easily causes co-adsorption of small molecule active organic substances, resulting in a decrease in the yield of the target active substances. This leads to a significant reduction in the efficacy and aroma of the extract.
[0005] Furthermore, ginseng extracts come from diverse sources, and the types and contents of odorous components vary depending on the origin and processing method. Existing deodorization methods have poor applicability and struggle to achieve efficient deodorization of ginseng extracts from different sources. Membrane separation technology, as a physical sieving process based on molecular weight, offers advantages such as room temperature operation, no chemical additives, and good retention of active ingredients, and has been applied in ginseng extraction and purification. However, there are no reports on its effective removal of odorous impurities of different molecular weights from ginseng extracts. Therefore, developing a multi-stage membrane separation preparation method that can efficiently remove the odor from ginseng extracts, fully retain active ingredients, and has universal applicability has become a pressing technical problem to be solved in the field of ginseng deep processing. Summary of the Invention
[0006] The purpose of this invention is to overcome the shortcomings of existing ginseng extract deodorization methods, such as loss of effective components, poor deodorization effect, and limited applicability. This invention provides a method for preparing ginseng extracts that significantly reduces the earthy smell of ginseng using multi-stage membrane separation. This method uses multi-stage membranes with specific pore sizes for step-by-step separation, which can efficiently remove earthy smell components of different molecular weights, fully retain the effective components of ginseng, and is applicable to ginseng extracts from different sources.
[0007] The objective of this invention is achieved through the following technical solution: A method for reducing the earthy taste of ginseng extract using multi-stage membrane separation mainly includes the following steps: (1) Dissolve ginseng extract in an ethanol solution with a volume fraction of 28-32% (preferably 30%) to prepare a ginseng extract solution with a dry matter concentration of 8-12% (preferably 10%). (2) The ginseng extract is subjected to multi-stage membrane separation at room temperature and with a transmembrane pressure difference of 0.2 to 0.5 MPa. The permeate from the previous stage of membrane separation is used as the feed liquid for the next stage of membrane separation, and the retentate from each stage of membrane separation is collected. (3) Combine the retentates obtained in step (2) and remove the solvent to obtain ginseng extract with reduced soil flavor.
[0008] The more specific steps of this invention are as follows: 1. Dissolution treatment: Dissolve the ginseng extract in an ethanol solution with a volume fraction of 28-32% to prepare a ginseng extract solution with a dry matter concentration of 8-12%. The ginseng extract can be commercially available ginseng extract paste, ginseng tincture or other conventional ginseng extracts. No pretreatment is required. It is suitable for ginseng raw materials from different sources and has a wider range of applications.
[0009] 2. Multistage membrane separation: The ginseng extract was purified stepwise using a multistage membrane coupling technique. The entire process was carried out at room temperature and a transmembrane pressure difference of 0.2-0.5 MPa to avoid the destruction of the active ingredients of ginseng by high temperatures. The specific steps and parameters are as follows: (1) First-stage membrane separation: A microfiltration membrane with a pore size of 50 nm was used for separation to preliminarily filter the ginseng extract and collect the retentate of this stage; (2) Second-stage membrane separation: The permeate obtained from the first-stage membrane separation is fed into an ultrafiltration membrane with a pore size of 10 kDa for separation, and the retentate of this stage is collected; (3) Third-stage membrane separation: The permeate obtained from the second-stage membrane separation is fed into a nanofiltration membrane with a pore size of 5 nm for separation, and the retentate of this stage is collected; (4) Fourth-stage membrane separation: The permeate obtained from the third-stage membrane separation is fed into a nanofiltration membrane with a pore size of 3 nm for separation, and the retentate of this stage is collected; (5) Fifth stage membrane separation: The permeate obtained from the fourth stage membrane separation is sent to an ultrafiltration membrane with a molecular weight cutoff of 1 kDa for separation, and finally the residual trace small molecule soil odor impurities are removed to ensure that the soil odor is completely removed. The retentate of this stage is collected and the permeate is discarded.
[0010] 3. Concentration and Combination: All retentates collected from the five-stage membrane separation process are combined and solvents are removed by vacuum concentration or freeze-drying to obtain ginseng extract with significantly reduced odor. The vacuum concentration temperature is controlled below 45°C to further prevent denaturation of ginseng active ingredients due to high temperature, and the freeze-drying temperature is controlled between -40°C and -50°C to ensure stable extract quality.
[0011] The preparation method and application of the present invention have the following beneficial effects: 1. Significant removal of earthy odor: Through multi-stage separation using membranes at 50nm, 10kDa, 5nm, 3nm, and 1kDa, the physical sieving mechanism of membrane separation is utilized to precisely classify and retain ginseng extract according to molecular weight, significantly reducing the earthy odor and improving the sensory quality of the extract. The deodorization effect is superior to existing single-membrane separation and traditional deodorization methods. 。
[0012] 2. Complete Preservation of Active Ingredients: This invention employs a room-temperature, low-pressure multi-stage membrane separation process with no added chemical reagents throughout. It is a purely physical separation process, effectively avoiding the damage to ginseng's active ingredients caused by chemical reagent residues and high temperatures. Simultaneously, by precisely controlling the pore size and separation parameters of each membrane stage, it efficiently deodorizes while fully preserving core active ingredients such as ginsenosides, polysaccharides, and amino acids (further testing shows that ginsenosides in the treated sample maintain a high retention level) (see Table 3). This does not affect the efficacy of ginseng extract and solves the problem of active ingredient loss caused by existing deodorization methods.
[0013] 3. Wide applicability: This method is not limited by the source of ginseng extract (different origins and processing methods), and has a good deodorizing effect on various commercially available ginseng extracts, ginseng tinctures and conventional ginseng extracts, with a wide range of applications; at the same time, the multi-stage membrane separation process is simple to operate, highly automated, and can realize continuous production, reducing energy consumption by 40% to 50% compared with traditional evaporation and concentration, making it suitable for industrial promotion and application. Detailed Implementation
[0014] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention. Example 1
[0015] Take 10g of commercially available ginseng extract, add 90g of 30% ethanol solution, stir well, and after dissolving, obtain a ginseng extract with a dry matter concentration of 10%.
[0016] The ginseng extract was placed in a multi-stage membrane separation device and separated stepwise under ambient temperature and a transmembrane pressure difference of 0.3 MPa: First, the permeate was passed through a microfiltration membrane with a pore size of 50 nm, and the retentate was collected; the permeate was then passed through an ultrafiltration membrane with a pore size of 10 kDa, and the retentate was collected; the permeate was then passed through a nanofiltration membrane with a pore size of 5 nm, and the retentate was collected; the permeate was then passed through a nanofiltration membrane with a pore size of 3 nm, and the retentate was collected; finally, the permeate was passed through an ultrafiltration membrane with a molecular weight cutoff of 1 kDa, and the retentate was collected.
[0017] All the retentate collected by the five-stage membrane separation were combined, concentrated under reduced pressure (temperature 40℃), and then freeze-dried (temperature -45℃) to remove moisture, resulting in ginseng extract 1# with significantly reduced earthy odor. Example 2
[0018] Take 15g of conventional ginseng extract, add 135g of 30% ethanol solution, stir well, and after dissolving, obtain a ginseng extract with a dry matter concentration of 10%.
[0019] The ginseng extract was placed in a multi-stage membrane separation device and separated stepwise under ambient temperature and a transmembrane pressure difference of 0.3 MPa: First, the permeate was passed through a microfiltration membrane with a pore size of 50 nm, and the retentate was collected; the permeate was then passed through an ultrafiltration membrane with a pore size of 10 kDa, and the retentate was collected; the permeate was then passed through a nanofiltration membrane with a pore size of 5 nm, and the retentate was collected; the permeate was then passed through a nanofiltration membrane with a pore size of 3 nm, and the retentate was collected; finally, the permeate was passed through an ultrafiltration membrane with a molecular weight cutoff of 1 kDa, and the retentate was collected.
[0020] All the retentate collected by the above five-stage membrane separation was combined and the water was removed by freeze drying (temperature -40℃) to obtain ginseng extract 2# with significantly reduced soil odor. Example 3
[0021] Take 20g of ginseng tincture, add 180g of 30% ethanol solution, stir well, and after dissolving, obtain ginseng extract with a dry matter concentration of 10%.
[0022] The ginseng extract was placed in a multi-stage membrane separation device and separated stepwise under ambient temperature and a transmembrane pressure difference of 0.3 MPa: First, the permeate was passed through a microfiltration membrane with a pore size of 50 nm, and the retentate was collected; the permeate was then passed through an ultrafiltration membrane with a pore size of 10 kDa, and the retentate was collected; the permeate was then passed through a nanofiltration membrane with a pore size of 5 nm, and the retentate was collected; the permeate was then passed through a nanofiltration membrane with a pore size of 3 nm, and the retentate was collected; finally, the permeate was passed through an ultrafiltration membrane with a molecular weight cutoff of 1 kDa, and the retentate was collected.
[0023] All the retentate collected by the five-stage membrane separation were combined, concentrated under reduced pressure (temperature 40℃), and then freeze-dried (temperature -45℃) to remove moisture, resulting in ginseng extract 3# with significantly reduced soil odor. Comparative Example 1
[0024] Take 20g of ginseng tincture, add 180g of 30% ethanol solution, stir well, and after dissolving, obtain ginseng extract with a dry matter concentration of 10%.
[0025] The above ginseng extract was placed in a single-stage membrane separation device and separated under normal temperature and 0.3 MPa transmembrane pressure difference conditions: the extract was fed into an ultrafiltration membrane with a pore size of 10 kDa and the retentate was collected.
[0026] All the retentate collected by the 10kDa ultrafiltration membrane was concentrated under reduced pressure (40℃) and then freeze-dried (-45℃) to remove water, yielding ginseng extract #4. Comparative Example 2
[0027] Take 20g of ginseng tincture, add 180g of 30% ethanol solution, stir well, and after dissolving, obtain ginseng extract with a dry matter concentration of 10%.
[0028] Place the above ginseng extract in an Erlenmeyer flask, add 3% (calculated based on solvent volume) of activated carbon with a particle size of 1-35μm at room temperature, stir with a magnetic stirrer for 60 minutes, and filter the above-treated extract through filter paper to obtain the filtrate.
[0029] The filtrate was concentrated under reduced pressure (40°C) and then freeze-dried (-45°C) to remove moisture, yielding ginseng extract 5#. Experimental Example
[0030] Sensory evaluations were conducted on three ginseng extracts prepared by multi-stage membrane separation with significantly reduced soil-like odor, and two ginseng extracts prepared by activated carbon and single-stage membrane separation. Untreated raw ginseng extract (corresponding to the three raw materials mentioned above) was used as a control. The soil-like odor and aroma of the samples were scored (out of 10; a lighter soil-like odor and purer aroma resulted in a higher score). The retention rate of ginsenosides (the core active ingredient) was also measured. The results are as follows: Five professional sensory evaluators conducted the evaluation. The results showed that the original ginseng extract, conventional ginseng extract, and ginseng tincture all scored 4.0-4.7 points, exhibiting a noticeable earthy odor. The ginseng extract prepared according to this invention, with significantly reduced earthy odor, scored 8.6-9.3 points, showed no obvious earthy odor, and possessed a pure aroma, retaining the inherent aroma characteristics of ginseng. (See Tables 1, 2, and 3.) The content of ginsenosides was detected by high performance liquid chromatography. The results showed that the retention rate of ginsenosides in the three extracts prepared by this invention was ≥98%, which proves that the method of this invention can fully retain the core effective components of ginseng while efficiently deodorizing.
[0031]
Claims
1. A method for reducing the earthy taste of ginseng extract using multi-stage membrane separation, characterized in that, Includes the following steps: (1) Dissolve ginseng extract in an ethanol solution with a volume fraction of 28-32% to prepare a ginseng extract solution with a dry matter concentration of 8-12%; (2) The ginseng extract is subjected to multi-stage membrane separation at room temperature and with a transmembrane pressure difference of 0.2 to 0.5 MPa. The permeate from the previous stage of membrane separation is used as the feed liquid for the next stage of membrane separation, and the retentate from each stage of membrane separation is collected. (3) Combine the retentates obtained in step (2) and remove the solvent to obtain ginseng extract with reduced soil flavor.
2. The preparation method according to claim 1, characterized in that: The multi-stage membrane separation described in step (2) is a five-stage membrane separation.
3. The preparation method according to claim 1 or 2, characterized in that: In step (2), the first-stage membrane separation uses a microfiltration membrane with a pore size of 50 nm; the second-stage membrane separation uses an ultrafiltration membrane with a pore size of 10 kDa; the third-stage membrane separation uses a nanofiltration membrane with a pore size of 5 nm; the fourth-stage membrane separation uses a nanofiltration membrane with a pore size of 3 nm; and the fifth-stage membrane separation uses a membrane with a molecular weight cutoff of 1 kDa.
4. The preparation method according to claim 1 or 2, characterized in that: The specific steps and parameters are as follows: (1) First-stage membrane separation: A microfiltration membrane with a pore size of 50 nm was used for separation to preliminarily filter the ginseng extract and collect the retentate of this stage; (2) Second-stage membrane separation: The permeate obtained from the first-stage membrane separation is fed into an ultrafiltration membrane with a pore size of 10 kDa for separation, and the retentate of this stage is collected; (3) Third-stage membrane separation: The permeate obtained from the second-stage membrane separation is fed into a nanofiltration membrane with a pore size of 5 nm for separation, and the retentate of this stage is collected; (4) Fourth-stage membrane separation: The permeate obtained from the third-stage membrane separation is fed into a nanofiltration membrane with a pore size of 3 nm for separation, and the retentate of this stage is collected; (5) Fifth stage membrane separation: The permeate obtained from the fourth stage membrane separation is sent to an ultrafiltration membrane with a molecular weight cutoff of 1 kDa for separation, and finally the residual trace small molecule soil odor impurities are removed to ensure that the soil odor is completely removed. The retentate of this stage is collected and the permeate is discarded.
5. The preparation method according to claim 1, characterized in that: The solvent removal method in step (3) is vacuum concentration and freeze drying.
6. The preparation method according to claim 5, characterized in that: The vacuum concentration temperature is controlled below 45°C, and the freeze-drying temperature is controlled between -40°C and -50°C.
7. The preparation method according to claim 1, characterized in that: The ginseng extract is selected from one or more of commercially available ginseng extract, ginseng tincture, and conventional ginseng extract.