A pretreatment method for improving the dissolution of active components of ginseng by low-temperature plasma

Abstract

This application discloses a pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma, comprising the following steps: S1, cutting the Gastrodia elata raw material according to the tuber part to obtain Gastrodia elata slices of different parts; S2, subjecting the Gastrodia elata slices of different parts to a first-stage plasma treatment, wherein the first-stage plasma treatment is dielectric barrier discharge treatment, and the gas atmosphere in the reaction chamber is controlled by dynamic gas exchange during the treatment; S3, subjecting the Gastrodia elata slices treated in the first stage to a second-stage plasma treatment, wherein the second-stage plasma treatment is atmospheric pressure plasma jet treatment with an oxygen-containing gas atmosphere; S4, subjecting the Gastrodia elata slices treated in the second stage to a third-stage treatment, wherein the third-stage treatment is gradient vacuum pulse cell disruption treatment, to obtain pretreated Gastrodia elata material. This application can improve the dissolution rate of gastrodin.

Description

Technical Field

[0001] This invention relates to the field of plant extraction pretreatment technology, specifically to a pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma. Background Technology

[0002] Gastrodia elata is a perennial parasitic plant belonging to the genus Gastrodia in the Orchidaceae family. Its dried tuber is a traditional and precious Chinese medicinal material. Modern research shows that the main active ingredients in Gastrodia elata include gastrodin, p-hydroxybenzyl alcohol, gastrodia polysaccharides, gastrodin ether glycosides, and vanillin, which possess various pharmacological activities such as sedation and hypnosis, neuroprotection, anticonvulsant effects, anti-aging, blood pressure reduction, anti-inflammatory, and antioxidant effects. The extraction efficiency of the active ingredients in Gastrodia elata is fundamentally limited by its dense plant cell wall and fiber bundle tissue structure. Currently, commonly used extraction methods include traditional thermal extraction, ultrasonic-assisted extraction, enzymatic pretreatment, and supercritical fluid extraction. However, these methods suffer from problems such as long extraction time, poor batch-to-batch stability, and the potential damage to heat-sensitive components caused by high-temperature and high-pressure environments.

[0003] In recent years, low-temperature plasma technology, as a novel non-thermal processing method, has been gradually introduced into the field of plant active ingredient extraction. This technology generates high-energy active particles such as high-energy electrons and reactive oxygen / nitrogen species (ROS / RNS), which can physically etch and chemically modify plant cell walls under normal temperature conditions, effectively reducing mass transfer resistance.

[0004] For example, the prior art CN120754011A discloses a method for preparing Gastrodia elata extract. This method involves mixing Gastrodia elata powder with an ethanol-water solution, subjecting the mixture to low-temperature plasma treatment at 20–30°C, and then performing countercurrent extraction in the same equipment. While this method achieves good extraction results, the low-temperature plasma treatment and countercurrent extraction are continuously completed within the same extraction tank, without physical separation between treatment and extraction. This results in high equipment integration but poor flexibility, making it difficult to optimize treatment and extraction parameters separately based on raw material characteristics. Furthermore, the low-temperature plasma treatment in this method involves a mixture of Gastrodia elata powder and an ethanol-water solution. The presence of the liquid medium significantly absorbs and scatters the high-energy active particles generated by the plasma, weakening its direct etching effect on the cell wall. Simultaneously, the dispersion state of the powder in the liquid makes it difficult to ensure uniform processing. Summary of the Invention

[0005] This invention provides a pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma, which can efficiently disrupt the cell wall structure of Gastrodia elata and improve subsequent extraction efficiency. To achieve the above objectives, this application provides the following technical solution: A pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma includes the following steps: S1. Control the moisture content of the Gastrodia elata raw material to 8%-30%, and cut the Gastrodia elata raw material according to the tuber part to obtain Gastrodia elata slices of different parts; S2. The first stage of plasma treatment is performed on the gastrodia elata slices from different parts. The first stage of plasma treatment is dielectric barrier discharge treatment, with a discharge voltage of 20-60 kV and a treatment temperature of 15-35℃. During the treatment, the gas atmosphere in the reaction chamber is controlled by dynamic air exchange. S3. The Gastrodia elata slices that have undergone the first stage of treatment are subjected to a second stage of plasma treatment. The second stage of plasma treatment is atmospheric pressure plasma jet treatment in an oxygen-containing gas atmosphere. The discharge voltage is 10-40 kV, the treatment temperature is 15-35℃, and the treatment time is 3-5 min. S4. The Gastrodia elata slices that have undergone the second stage of treatment are subjected to a third stage of treatment, which is a gradient vacuum pulse cell disruption treatment, including: placing the Gastrodia elata slices in a vacuum chamber, reducing the vacuum degree from atmospheric pressure to 1-5 kPa within 5-15 s, maintaining it for 30-120 s, and then restoring it to atmospheric pressure within 3-10 s, repeating this process 2-5 times; to obtain the pretreated Gastrodia elata material.

[0006] As a preferred embodiment, in step S1, the Gastrodia elata tuber is cut into head slices, middle slices, and tail slices with a thickness of 3-10 mm. The head slice is the slice near the bud end, and the tail slice is the slice near the navel end.

[0007] As a preferred embodiment, the dielectric barrier discharge treatment time for the head sheet is 1 to 3 minutes, the dielectric barrier discharge treatment time for the middle sheet is 3 to 6 minutes, and the dielectric barrier discharge treatment time for the tail sheet is 5 to 10 minutes.

[0008] As a preferred embodiment, the dynamic ventilation method involves continuously introducing a mixture of air and argon at a flow rate of 0.5–3 L / min, with the volume ratio of air to argon being 1:1–3:1, while simultaneously extracting exhaust gas at the same flow rate.

[0009] As a preferred embodiment, the first stage of plasma treatment is carried out in a closed reaction chamber. Before introducing the mixed gas, the reaction chamber is first evacuated to 1-10 kPa, and then the mixed gas is introduced to atmospheric pressure.

[0010] As a preferred embodiment, the method further includes extracting the pretreated Gastrodia elata slices; the extraction solvent is water or an aqueous solution of ethanol with a volume fraction of 30%-80%, the extraction temperature is 30-70℃, and the extraction time is 20-120 minutes.

[0011] Application of pretreated Gastrodia elata material obtained according to the above method in the preparation of Gastrodia elata extract.

[0012] Working principle and beneficial effects of the present invention: (1) The first stage of plasma treatment generates a large area of ​​uniform plasma in the electrode coverage area, which uniformly activates the cell wall on the surface of the Gastrodia elata slice to obtain a microcrack network. The second stage of plasma treatment transforms the microcracks into penetrating deep holes, and the uniformity of the treatment is greatly improved compared with the single jet.

[0013] (2) The first stage of plasma treatment uses an air-argon mixture as the working gas. Argon reduces the breakdown threshold and stabilizes the discharge. The second stage of plasma treatment switches to pure oxygen as the working gas, generating high-concentration oxygen free radicals to carry out high-intensity oxidation expansion of the microcrack depth and increase the crack depth. The third stage of vacuum pulse uses pressure difference to apply load to the damaged weak area, so that the microcracks preferentially expand to penetration along the damage path.

[0014] (3) No organic solvents, enzyme preparations or chemical cell wall disruption aids are added during the entire pretreatment process. Only active species generated by plasma discharge using air, argon and oxygen are used to perform physical-chemical synergistic cell wall disruption. There are no harmful chemical residues during the process. The solvents used in the extraction step are only water or food-grade ethanol aqueous solution. The overall process meets the standards and requirements of green pharmaceutical and environmentally friendly production. No additional solvent recovery or residue removal processes are required, which reduces production costs and environmental burden. Attached Figure Description

[0015] Figure 1 This is a flowchart of a low-temperature plasma-enhanced pretreatment method for dissolving active ingredients from Gastrodia elata, as described in this application. Figure 2 for Figure 1 Vacuum degree-time graph of the third stage of vacuum pulse processing; Detailed Implementation The following detailed description illustrates the specific implementation method: Example 1: A pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma, comprising the following steps: (1) Raw material preparation: Select fresh Gastrodia elata from Bijie, wash and dry it until the moisture content is 20%. Cut the Gastrodia elata tuber into head slices (arrow bud end), middle slices and tail slices (navel end) according to the part, and the thickness of each slice is 5mm; (2) First stage dielectric barrier discharge treatment: Place the Gastrodia elata slices in a sealable reaction chamber, first evacuate to 5 kPa, then introduce a mixture of air and argon (volume ratio 2:1) to atmospheric pressure. Maintain a stable atmosphere using dynamic gas exchange (inlet flow rate 1.5 L / min, outlet flow rate 1.5 L / min). Discharge voltage 40 kV, electrode spacing 5 mm, temperature 25 °C. Treat the head slices for 2 minutes, the middle slices for 4 minutes, and the tail slices for 7 minutes; (3) Second stage jet treatment: working gas is oxygen, discharge voltage is 25kV, treatment time is 2 minutes, and temperature is 25℃.

[0016] (4) Third vacuum pulse: Transfer to vacuum chamber, reduce pressure from atmospheric pressure to 3 kPa within 10 seconds, maintain for 60 seconds, restore atmospheric pressure within 5 seconds, repeat 3 times.

[0017] (5) Extraction: Add 50% ethanol aqueous solution (material-liquid ratio 1:10) and extract at 50℃ for 60 minutes.

[0018] The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 9.12 mg / g.

[0019] Example 2: A pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma, comprising the following steps: (1) Raw material preparation: dry to a moisture content of 12% and slice thickness of 3mm.

[0020] (2) First stage DBD treatment: Evacuate to 3 kPa, and introduce air and argon (volume ratio 1:1) to atmospheric pressure. Dynamic gas exchange flow rate 1 L / min. Discharge voltage 50 kV, electrode spacing 3 mm, temperature 20 °C. Head plate 1.5 minutes, middle plate 3 minutes, tail plate 6 minutes.

[0021] (3) Second stage jet treatment: oxygen, discharge voltage 30kV, treatment time 1.5 minutes, temperature 20℃.

[0022] (4) Third vacuum pulse: Reduce to 2 kPa within 8 seconds, maintain for 90 seconds, recover within 4 seconds, repeat 4 times.

[0023] (5) Extraction: Water (solid-liquid ratio 1:12), extract at 60℃ for 40 minutes.

[0024] The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 8.76 mg / g.

[0025] Example 3: A pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma (1) Raw material preparation: dry to a moisture content of 25% and slice thickness of 8mm.

[0026] (2) First stage DBD treatment: Evacuate to 8 kPa, and introduce air and argon (volume ratio 3:1) to atmospheric pressure. Dynamic gas exchange flow rate 2.5 L / min. Discharge voltage 30 kV, electrode spacing 8 mm, temperature 35 °C. Head plate 3 minutes, middle plate 5 minutes, tail plate 9 minutes.

[0027] (3) Second stage jet treatment: oxygen, discharge voltage 20kV, treatment time 3 minutes, temperature 35℃.

[0028] (4) Third vacuum pulse: Reduce to 4 kPa within 12 seconds, maintain for 120 seconds, recover within 8 seconds, repeat twice.

[0029] (5) Extraction: 30% ethanol aqueous solution (material-liquid ratio 1:8), extract at 40℃ for 90 minutes.

[0030] The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 8.31 mg / g.

[0031] Comparative Example 1: The only difference from Example 1 is that the third vacuum pulse process is not performed. All other conditions are the same.

[0032] The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 7.58 mg / g.

[0033] Comparative Example 2: The only difference from Example 1 is that the first stage of DBD treatment is carried out in a closed static atmosphere, without the introduction of fresh gas or the extraction of exhaust gas. All other conditions are the same.

[0034] The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 7.92 mg / g.

[0035] Comparative Example 3: The only difference from Example 1 is that no distinction was made between different parts of Gastrodia elata, and all Gastrodia elata slices were processed using the same DBD parameters (processing time 5 minutes). All other conditions were the same.

[0036] The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 7.35 mg / g.

[0037] Comparative Example 4: The diced Gastrodia elata slices (head slices, middle slices, and tail slices) were directly subjected to the second stage of jet treatment (oxygen, 25 kV, 2 minutes, 25°C), followed by the third stage of vacuum pulse treatment (reducing to 3 kPa within 10 seconds, maintaining for 60 seconds, recovering within 5 seconds, repeated 3 times). Finally, extraction was performed according to the conditions of Example 1 (50% ethanol, 1:10, 50°C, 60 minutes). The head slices, middle slices, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 6.35 mg / g.

[0038] Comparative Example 5: The diced Gastrodia elata slices underwent a first-stage DBD treatment (2 minutes for the head, 4 minutes for the middle, and 7 minutes for the tail, air:argon = 2:1, 40kV, dynamic atmosphere), followed by a third-stage vacuum pulse treatment (reducing to 3kPa within 10 seconds, maintaining for 60 seconds, recovering within 5 seconds, repeated 3 times). Finally, extraction was performed according to the conditions of Example 1. The head, middle, and tail slices were mixed and extracted together. The mixed extract was analyzed by HPLC, and the gastrodin content was 6.50 mg / g.

[0039] Blank control group: Fresh Gastrodia elata from Bijie was washed, dried to a moisture content of 20%, and cut into head slices, middle slices and tail slices (5 mm thick) according to the parts. Without any pretreatment, the slices were directly mixed and then added to a 50% ethanol aqueous solution (material-liquid ratio 1:10). The mixture was extracted at 50℃ for 60 minutes. The extract was then analyzed by HPLC, and the gastrodin content was 3.95 mg / g.

[0040] In summary, this application, by combining dynamic atmosphere control and differentiated treatment of different parts, achieved a gastrodin dissolution rate of 9.12 mg / g, which is more than double that of the blank control group.

[0041] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A pretreatment method for enhancing the dissolution of active ingredients from Gastrodia elata using low-temperature plasma, characterized in that, Includes the following steps: S1. Control the moisture content of the Gastrodia elata raw material to 8%-30%, and cut the Gastrodia elata raw material according to the tuber part to obtain Gastrodia elata slices of different parts; S2. The first stage of plasma treatment is performed on the gastrodia elata slices from different parts. The first stage of plasma treatment is dielectric barrier discharge treatment, with a discharge voltage of 20-60 kV and a treatment temperature of 15-35℃. During the treatment, the gas atmosphere in the reaction chamber is controlled by dynamic air exchange. S3. The Gastrodia elata slices that have undergone the first stage of treatment are subjected to a second stage of plasma treatment. The second stage of plasma treatment is atmospheric pressure plasma jet treatment in an oxygen-containing gas atmosphere. The discharge voltage is 10-40 kV, the treatment temperature is 15-35℃, and the treatment time is 3-5 min. S4. The Gastrodia elata slices that have undergone the second stage of treatment are subjected to a third stage of treatment, which is a gradient vacuum pulse cell disruption treatment, including: placing the Gastrodia elata slices in a vacuum chamber, reducing the vacuum degree from atmospheric pressure to 1-5 kPa within 5-15 s, maintaining it for 30-120 s, and then restoring it to atmospheric pressure within 3-10 s, repeating this process 2-5 times; to obtain the pretreated Gastrodia elata material.

2. The pretreatment method according to claim 1, characterized in that, Step S1: Cut the Gastrodia elata tuber into head slices, middle slices, and tail slices with a thickness of 3-10mm. The head slice is the slice near the bud end, and the tail slice is the slice near the navel end.

3. The pretreatment method according to claim 2, characterized in that, The dielectric barrier discharge treatment time for the head piece is 1 to 3 minutes, the dielectric barrier discharge treatment time for the middle piece is 3 to 6 minutes, and the dielectric barrier discharge treatment time for the tail piece is 5 to 10 minutes.

4. The pretreatment method according to claim 3, characterized in that, The dynamic ventilation method involves continuously introducing a mixture of air and argon at a flow rate of 0.5–3 L / min, with the volume ratio of air to argon being 1:1–3:1, while simultaneously extracting exhaust gas at the same flow rate.

5. The pretreatment method according to claim 4, characterized in that, The first stage of plasma treatment is carried out in a closed reaction chamber. Before the mixed gas is introduced, the reaction chamber is evacuated to 1-10 kPa, and then the mixed gas is introduced to atmospheric pressure.

6. The pretreatment method according to claim 5, characterized in that, It also includes extracting the pretreated Gastrodia elata slices; the extraction solvent is water or an aqueous solution of ethanol with a volume fraction of 30%-80%, the extraction temperature is 30-70℃, and the extraction time is 20-120 minutes.

7. The use of the pretreated Gastrodia elata material obtained by the method according to any one of claims 1 to 6 in the preparation of Gastrodia elata extract.

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