Directional preparation process of valerian-rich rhizoma nardostachyos essential oil

Abstract

The invention relates to the technical field of plant essential oil extraction, and discloses a valerian-rich rhizoma nardostachyos essential oil directional preparation process, which comprises: taking a functionalized compound solvent, adding rhizoma nardostachyos coarse powder according to a liquid-solid ratio, stirring and soaking to obtain a solid-liquid mixture; the solvent component comprises process water, sodium xylene sulfonate, dipotassium phosphate and polyethylene glycol 400; introducing steam into the mixture, heating to maintain slight boiling, carrying out first-stage distillation, and removing distilled low-boiling-point components to obtain resident in the kettle; cooling the resident to a constant temperature, adding sodium chloride, and stirring until the sodium chloride is dissolved to obtain a heterogeneous mixed system; the heating system is subjected to second-stage distillation, and distillate is collected; and carrying out oil-water separation on the distillate, and collecting an oil phase to obtain a finished product of the rhizoma nardostachyos essential oil. According to the method disclosed by the invention, a hydrotropy-salting-out phase change mechanism is matched with fractional distillation, so that high-efficiency desorption and directional enrichment of valerianone which is difficult to volatilize are realized while acidic and light component impurities are removed.

Description

Technical Field

[0001] This invention relates to the field of plant essential oil extraction technology, specifically a process for the targeted preparation of spikenard essential oil rich in valerone. Background Technology

[0002] Nardostachys jatamansi is a plant belonging to the Valerianaceae family. Its rhizome can be extracted to obtain Nardostachys jatamansi essential oil, which has the effects of regulating qi and relieving pain. Valerianone is a key sesquiterpene ketone active ingredient in essential oils, which has sedative activity and characteristic aroma. It belongs to high-boiling-point, low-volatility components, and its content is an important indicator for measuring the quality of essential oils.

[0003] Currently, steam distillation is the most common industrial method for extracting spikenard oil. This method utilizes the principle of steam azeotropism to extract volatile oils from plant tissues, which are then separated by condensation to obtain the product. Because of its mature technology and absence of organic solvent residue, it is the mainstream technology for preparing plant essential oils.

[0004] However, traditional steam distillation lacks selectivity for components. Due to the large molecular weight and high boiling point of valerone, it is difficult to completely desorb from the plant matrix under conventional distillation conditions, resulting in limited extraction rates. Simultaneously, the raw material *Nardostachys chinensis* contains a large amount of low-boiling-point monoterpenes and acidic impurities, which readily enter the oil phase with steam distillation, causing the finished essential oil to have a high acid value and be diluted with active components. Current technologies struggle to simultaneously achieve efficient release of high-boiling-point components and removal of low-boiling-point impurities during extraction, making it impossible to directly obtain high-purity valerone-rich essential oil.

[0005] Therefore, this invention proposes a targeted preparation process for spikenard oil rich in valerone to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a targeted preparation process for spikenard oil rich in valerone, which solves the problems of low extraction rate of high-boiling-point valerone by traditional steam distillation and difficulty in simultaneously separating low-boiling-point and acidic impurities, resulting in insufficient purity of the finished oil.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a process for the targeted preparation of spikenard essential oil rich in valerone, using the following technical solution:

[0009] A process for the targeted preparation of spikenard essential oil rich in valerone includes the following steps:

[0010] S1. Take the functionalized compound solvent, add the crude nardostachys chinensis powder according to the liquid-solid ratio, stir and soak to obtain a solid-liquid mixture; the components of the functionalized compound solvent include process water, sodium xylenesulfonate, dipotassium hydrogen phosphate and polyethylene glycol 400;

[0011] S2. Steam is introduced into the solid-liquid mixture to heat it and maintain a slight boil, and the first stage of distillation is carried out to remove the low-boiling-point components distilled off, thereby obtaining the residue in the vessel.

[0012] S3. Cool the contents of the reactor to a constant temperature, add sodium chloride and stir until dissolved to obtain a heterogeneous mixed system;

[0013] S4. Heat the heterogeneous mixture to perform a second-stage distillation and collect the distillate;

[0014] S5. Separate the distillate from the water and collect the oil phase to obtain the finished spikenard oil.

[0015] By adopting the above technical solution, this invention utilizes a combined process of solvent-assisted solubilization and salting-out phase change to achieve the directional separation of components in spikenard oil. The specific mechanism and effects are as follows:

[0016] Solubilization and Retention, and Removal of Acidic Impurities: In steps S1 and S2, sodium xylenesulfonate in the functionalized compound solvent acts as a water-soluble promoter, increasing the solubility of not only polar molecules but also weakly polar or non-polar sesquiterpene ketones (such as valerone) in the aqueous phase, thus reducing their activity coefficient in water. Dipotassium hydrogen phosphate maintains the system in a weakly alkaline environment, causing acidic components in the nard (such as spikenard acid) to neutralize with the alkali, generating non-volatile salts that dissolve in the aqueous phase. During the first-stage distillation process, acidic impurities are converted into salts and remain at the bottom of the vessel, not distilled off with the steam, thereby reducing the acid value of the finished essential oil and improving its aroma quality.

[0017] Separation effect of boiling point difference and relative volatility control: In the first stage of distillation in step S2, the volatility difference between components is used for preliminary separation. Low-boiling-point monoterpenoid components are less affected by the co-solvent and preferentially distill off with steam and are removed under low-boiling conditions. Meanwhile, the target product, valerone, due to its higher boiling point and the solubilizing effect of sodium xylenesulfonate, has its partition coefficient shifted towards the liquid phase in gas-liquid equilibrium, thus mainly remaining in the residue in the vessel. This achieves the removal of light component impurities and the enrichment of the target product.

[0018] Salting-out demulsification and target product release: In steps S3 and S4, sodium chloride is added to introduce a strong electrolyte. The ions generated by the dissociation of sodium chloride in water bind a large number of water molecules through hydration, causing instability in the solubilizing structure of sodium xylenesulfonate and reducing the solubility of the organic phase in the aqueous system (i.e., the salting-out effect). The solubility of hydrophobic components such as valerone, which were originally dissolved or dispersed in the aqueous phase, decreases, phase separation occurs, and their original volatility is restored. At this point, a second-stage distillation is performed, allowing the target product to be azeotropically distilled with steam, improving the extraction rate of the non-volatile components.

[0019] Preferably, in step S1, the functionalized compound solvent comprises the following components in parts by weight: process water: 100 parts by weight; sodium xylenesulfonate: 8.0 to 12.0 parts by weight; dipotassium hydrogen phosphate: 1.0 to 1.5 parts by weight; polyethylene glycol 400: 0.3 to 0.5 parts by weight.

[0020] By adopting the above technical solution, the concentration range of sodium xylenesulfonate is controlled to form an effective solubilizing system, ensuring the solubilizing effect on valerone; the ratio of dipotassium hydrogen phosphate to polyethylene glycol 400 maintains a stable pH value while utilizing the permeability of polyethylene glycol to promote the solvent to enter the plant tissue and improve mass transfer efficiency.

[0021] Preferably, in step S1, the pH value of the functionalized compound solvent is 8.0 to 8.5; the preparation method of the functionalized compound solvent is as follows: process water is placed under stirring, and sodium xylenesulfonate, dipotassium hydrogen phosphate and polyethylene glycol 400 are added in sequence and stirred until completely dissolved.

[0022] By adopting the above technical solution, the pH value is controlled between 8.0 and 8.5, which can fully convert the free acid in spikenard into salts and prevent it from entering the distillate. At the same time, this alkaline range is mild and avoids damaging the chemical structure of valerone.

[0023] Preferably, in step S1, the particle size of the spikenard powder is 20 to 40 mesh, and the moisture content is 8.0% to 12.0%; the liquid-solid ratio is 8:1 to 10:1, which is the ratio of the total mass of the functional compound solvent to the mass of the spikenard powder.

[0024] By adopting the above technical solution, the appropriate particle size and liquid-solid ratio ensure the contact area between the solvent and the material, avoid the adhesion caused by fine powder or the incomplete extraction caused by coarse powder, and ensure that the system has suitable fluidity to facilitate heat transfer.

[0025] Preferably, in step S1, the temperature of the stirring and soaking is 20°C to 30°C, and the time is 1.5 hours to 2.5 hours.

[0026] By adopting the above technical solution, soaking at room temperature allows plant fibers to absorb water and swell, increasing the permeability of the cell wall and facilitating the diffusion of intracellular essential oil components into the solvent.

[0027] Preferably, in step S2, the heating temperature of the first stage distillation is 98°C to 102°C, the reflux ratio R of the distillation column is set to 0.5 to 1.0, and the distillation duration is 1.5 hours to 2.0 hours.

[0028] By adopting the above technical solution, the temperature and reflux ratio in the first stage are controlled, and the fractionation capacity of the distillation column is utilized to allow low-boiling-point components to escape, while high-boiling-point components are condensed and refluxed back into the vessel, thereby improving the separation accuracy.

[0029] Preferably, in step S3, the constant temperature after cooling is 75°C to 85°C.

[0030] By adopting the above technical solution, the system is cooled to this range before adding salt, which is conducive to the rapid dissolution of sodium chloride, while preventing boiling or local overheating of the material caused by adding salt at high temperature.

[0031] Preferably, in step S3, the amount of sodium chloride added is 12.0 to 15.0 parts by weight, which is relative to the number of parts by weight of process water in the functionalized compound solvent; the stirring time until dissolution is 20 to 30 minutes.

[0032] By adopting the above technical solution, the amount of sodium chloride used can disrupt the solubilization equilibrium of sodium xylenesulfonate and achieve the critical ionic strength required for phase separation; the stirring operation ensures that the salt is evenly dispersed in the solid-liquid mixture.

[0033] Preferably, in step S4, the heating temperature of the second stage distillation is 102°C to 105°C, the reflux ratio R is set to 0, and full recovery is performed; the time for collecting the distillate is 2.5 hours to 4.0 hours, or until no obvious oil droplets flow out of the condenser outlet.

[0034] By adopting the above technical solution, increasing the distillation temperature and using a full recovery mode, combined with the increase in the boiling point of the aqueous phase caused by the salting-out effect, the carrying capacity of water vapor for free valerone is enhanced, thereby improving the recovery efficiency of the second-stage fraction.

[0035] Preferably, in step S5, the oil-water separation operation is as follows: the distillate is allowed to stand in an oil-water separator for 30 to 60 minutes to separate into layers, and the upper oil phase is obtained; 5% to 10% of anhydrous sodium sulfate is added to the upper oil phase for drying, and the product is obtained by filtration.

[0036] By adopting the above technical solution, most of the aqueous phase is removed by static stratification, and residual trace moisture is removed by drying with anhydrous sodium sulfate, thus ensuring the purity and stability of the finished product.

[0037] This invention provides a targeted preparation process for spikenard oil rich in valerone. It has the following beneficial effects:

[0038] 1. This invention achieves the targeted enrichment of non-volatile sesquiterpenoids through the synergistic effect of sodium xylenesulfonate as a solubilizer and sodium chloride as a salt-out. In the initial stage of the process, sodium xylenesulfonate increases the solubility of valerone in water, ensuring its retention in the vessel during the initial distillation phase. Later, sodium chloride is added to induce a salt-out effect, disrupting the solubilization equilibrium and reducing the solubility of the target component in the aqueous phase. This method alters the gas-liquid equilibrium of valerone, causing it to concentrate its distillation during the reboiling stage, thus solving the problem of low extraction rates of high-boiling-point components in conventional steam distillation.

[0039] 2. This invention adjusts the pH value of the solvent by adding dipotassium hydrogen phosphate, utilizing the principle of acid-base neutralization to selectively remove acidic impurities such as spikenard acid. The weakly alkaline environment converts volatile free acids into non-volatile salts, thus fixing them in the aqueous phase during distillation and preventing them from entering the oil phase with the steam. This measure lowers the acid value of the essential oil, removes rancid odors, and enhances the overall aroma quality of the essential oil while enriching valerone, eliminating the need for subsequent cumbersome deacidification and refining processes.

[0040] 3. This invention achieves effective separation of light and heavy components through a two-stage temperature control and reflux ratio adjustment process. The first stage removes low-boiling-point monoterpene impurities under low-boiling conditions while using a co-solvent to retain high-boiling-point components. The second stage combines phase recombination with increased distillation temperature to concentrate the valerone-rich fraction. This stepwise operation avoids purity reduction caused by impurities in the entire fraction. Through the combination of physical fractionation and chemical regulation, the goal of directionally preparing valerone-rich spikenard oil is achieved. Attached Figure Description

[0041] Figure 1 This is a graph showing the equilibrium solubility trend of valerone in different solvent systems according to the present invention.

[0042] Figure 2 Figure (a) shows the mass transfer distribution trend of the target substance and impurities under different pH conditions of the present invention, and Figure (b) shows the distribution rate of each component in the distillate and the distribution rate of each component in the residual liquid in the distillation flask. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0045] The raw material of Nardostachys jatamansi used in the embodiments of the present invention is the dried root and rhizome of Nardostachys jatamansi, a plant of the Valerianaceae family. It was purchased from the Sichuan medicinal materials market, and after harvesting, it was naturally dried with a moisture content controlled between 8.0% and 12.0%. Before use, it was crushed and filtered through a 20-40 mesh sieve to obtain coarse Nardostachys powder.

[0046] Sodium xylenesulfonate (CAS No.: 1300-72-7) is an industrial-grade dry powder with a purity ≥90.0%; polyethylene glycol 400 (CAS No.: 25322-68-3) is an industrial-grade product with an average molecular weight of 380-420; dipotassium hydrogen phosphate (CAS No.: 7758-11-4) is analytical grade; sodium chloride (CAS No.: 7647-14-5) is industrial refined salt with a purity ≥99.0%; anhydrous sodium sulfate (CAS No.: 7757-82-6) is analytical grade.

[0047] Preparation Example 1:

[0048] This preparation example provides a functionalized compound solvent for the extraction of spikenard essential oil, including the following steps:

[0049] Weigh 100 parts by weight of process water and place it in a mixing vessel. Turn on the stirring and control the speed at 60 rpm to 100 rpm. Add 10.0 parts by weight of sodium xylenesulfonate, 1.2 parts by weight of dipotassium hydrogen phosphate, and 0.4 parts by weight of polyethylene glycol 400 in sequence. Stir continuously at room temperature (25°C) for 15 to 20 minutes until all solid solutes are completely dissolved. After standing to remove foam, the pH value of the solution is measured to be 8.2, and a clear and transparent functionalized compound solvent A is obtained.

[0050] Preparation Example 2:

[0051] This preparation example provides a specialized functionalized compound solvent for the extraction of spikenard essential oil, comprising the following steps:

[0052] Weigh 100 parts by weight of process water and place it in a mixing vessel. Turn on the stirring and control the speed at 60 rpm to 100 rpm. Add 8.0 parts by weight of sodium xylenesulfonate, 1.0 part by weight of dipotassium hydrogen phosphate, and 0.3 parts by weight of polyethylene glycol 400 in sequence. Stir continuously for 15 to 20 minutes at room temperature (25°C) until all solid solutes are completely dissolved. After standing to remove foam, the pH value of the solution is measured to be 8.0, and a clear and transparent functionalized compound solvent B is obtained.

[0053] Preparation Example 3:

[0054] This preparation example provides a specialized functionalized compound solvent for the extraction of spikenard essential oil, comprising the following steps:

[0055] Weigh 100 parts by weight of process water and place it in a mixing vessel. Turn on the stirring and control the speed at 60 rpm to 100 rpm. Add 12.0 parts by weight of sodium xylenesulfonate, 1.5 parts by weight of dipotassium hydrogen phosphate, and 0.5 parts by weight of polyethylene glycol 400 in sequence. Stir continuously for 15 to 20 minutes at room temperature (25°C) until all solid solutes are completely dissolved. After standing to remove foam, the pH value of the solution is measured to be 8.5, and a clear and transparent functionalized compound solvent C is obtained.

[0056] Example 1:

[0057] This embodiment provides a process for the targeted preparation of spikenard essential oil rich in valerone, including the following steps:

[0058] (1) Raw material mixing: Take the functional compound solvent A obtained in Preparation Example 1 and put it into a reaction vessel with jacket heating and stirring function; add nardostachys chinensis powder at a liquid-to-solid ratio of 8:1 (total mass of functional compound solvent A: mass of nardostachys chinensis powder), stir and soak for 2.0 hours at room temperature of 25℃ and speed of 40rpm to fully swell the plant fiber and obtain a solid-liquid mixture.

[0059] (2) Co-solution extraction and initial distillation: Steam is introduced into the jacket of the reactor to heat the solid-liquid mixture to 100°C and maintain a slight boiling state; the reflux ratio of the distillation column is set to R=1, and the first stage of atmospheric distillation is carried out for 1.5 hours. The low-boiling light components are collected and removed to obtain the residue in the reactor. At this time, the target product valerone is solubilized in the aqueous phase in the reactor.

[0060] (3) Cooling and phase recombination: Stop the steam supply, introduce circulating cooling water into the jacket of the reactor, and reduce the temperature of the contents in the reactor to 80°C under stirring. Maintain constant temperature to obtain a cooling system.

[0061] (4) Phase change induction: Under constant temperature stirring at 80°C, 15.0 parts by weight of sodium chloride (relative to the weight of process water in Preparation Example 1) were added to the cooling system and stirred for 25 minutes until the solid salt was completely dissolved to obtain a heterogeneous mixed system.

[0062] (5) Directional reboiling distillation: Stop the cooling water supply, re-introduce steam into the reactor jacket, heat the heterogeneous mixture to 104°C, adjust the reflux ratio R=0 to perform full extraction; collect the second stage distillate for 3.0 hours until no obvious oil droplets flow out of the condenser outlet, and obtain the oil-water mixed distillate.

[0063] (6) Separation and refining: The oil-water mixed distillate is introduced into an oil-water separator and allowed to stand for 45 minutes to separate the layers, and the upper oil phase is obtained. 10% of the oil phase by mass of anhydrous sodium sulfate is added to the upper oil phase for drying and filtration to obtain the finished spikenard oil.

[0064] Example 2:

[0065] This embodiment provides a process for the targeted preparation of spikenard essential oil rich in valerone, including the following steps:

[0066] (1) Raw material mixing: Take the functionalized compound solvent B obtained in Preparation Example 2 and put it into a reaction vessel with jacket heating and stirring function; add nardostachys chinensis powder at a liquid-to-solid ratio of 8:1 (total mass of functionalized compound solvent B: mass of nardostachys chinensis powder), stir and soak for 1.5 hours at room temperature of 20℃ and speed of 30rpm to obtain a solid-liquid mixture.

[0067] (2) Co-solution extraction and initial distillation: Steam is introduced into the jacket of the reactor to heat the solid-liquid mixture to 98°C and maintain a slight boiling state; the reflux ratio of the distillation column is set to R=0.5, and the first stage of atmospheric distillation is carried out for 1.5 hours. The low-boiling light components distilled are collected and removed to obtain the residue in the reactor.

[0068] (3) Cooling and phase recombination: Stop the steam supply, introduce circulating cooling water into the jacket of the reactor, and reduce the temperature of the contents in the reactor to 85°C under stirring. Maintain constant temperature to obtain a cooling system.

[0069] (4) Phase change induction: Under constant temperature stirring at 85°C, 12.0 parts by weight of sodium chloride (relative to the weight of process water in Preparation Example 2) were added to the cooling system and stirred for 20 minutes until the solid salt was completely dissolved to obtain a heterogeneous mixed system.

[0070] (5) Directional reboiling distillation: Stop the cooling water supply, re-introduce steam into the reactor jacket, heat the heterogeneous mixture to 102°C, adjust the reflux ratio R=0 to perform full extraction; collect the second stage distillate for 2.5 hours until no obvious oil droplets flow out of the condenser outlet, and obtain the oil-water mixed distillate.

[0071] (6) Separation and refining: The oil-water mixed distillate is introduced into an oil-water separator and allowed to stand for 30 minutes to separate the layers, and the upper oil phase is obtained. 5% of the oil phase by mass of anhydrous sodium sulfate is added to the upper oil phase for drying and filtration to obtain the finished spikenard oil.

[0072] Example 3:

[0073] This embodiment provides a process for the targeted preparation of spikenard essential oil rich in valerone, including the following steps:

[0074] (1) Raw material mixing: Take the functionalized compound solvent C obtained in Preparation Example 3 and put it into a reaction vessel with jacket heating and stirring function; add nardostachys chinensis powder at a liquid-to-solid ratio of 10:1 (total mass of functionalized compound solvent C: mass of nardostachys chinensis powder), stir and soak for 2.5 hours at room temperature of 30℃ and speed of 50rpm to obtain a solid-liquid mixture.

[0075] (2) Co-solution extraction and initial distillation: Steam is introduced into the jacket of the reactor to heat the solid-liquid mixture to 102°C and maintain a slight boiling state; the reflux ratio of the distillation column is set to R=1.0, and the first stage of atmospheric distillation is carried out for 2.0 hours. The low-boiling light components distilled are collected and removed to obtain the residue in the reactor.

[0076] (3) Cooling and phase recombination: Stop the steam supply, introduce circulating cooling water into the reactor jacket, and reduce the temperature of the contents in the reactor to 75°C under stirring. Maintain constant temperature to obtain a cooling system.

[0077] (4) Phase change induction: Under constant temperature stirring at 75°C, 15.0 parts by weight of sodium chloride (relative to the weight of process water in Preparation Example 3) were added to the cooling system and stirred for 30 minutes until the solid salt was completely dissolved to obtain a heterogeneous mixed system.

[0078] (5) Directional reboiling distillation: Stop the cooling water supply, re-introduce steam into the reactor jacket, heat the heterogeneous mixture to 105°C, adjust the reflux ratio R=0 to perform full extraction; collect the second stage distillate for 4.0 hours until no obvious oil droplets flow out of the condenser outlet, and obtain the oil-water mixed distillate.

[0079] (6) Separation and refining: The oil-water mixed distillate is introduced into an oil-water separator and allowed to stand for 60 minutes to separate the layers, and the upper oil phase is obtained. 10% of the mass of anhydrous sodium sulfate is added to the upper oil phase for drying and filtration to obtain the finished spikenard oil.

[0080] Comparative Example 1:

[0081] Compared with Example 1, the difference is that in step (1), the functionalized compound solvent A is replaced with an equal mass of pure process water; in step (4), sodium chloride is not added, but the mixture is stirred at a constant temperature of 80°C for 25 minutes, and then the directional reboiling distillation in step (5) is carried out; the remaining steps are the same as in Example 1.

[0082] Comparative Example 2:

[0083] Compared with Example 1, the difference is that sodium xylenesulfonate was not added to the functional compound solvent used in step (1) during preparation, and the remaining components and amounts were consistent with those in Example 1; the remaining steps were the same as those in Example 1.

[0084] Comparative Example 3:

[0085] Compared with Example 1, the difference is that sodium chloride is not added in step (4), but after stirring at a constant temperature of 80°C for 25 minutes, the directional reboiling distillation in step (5) is carried out directly; the remaining steps are the same as in Example 1.

[0086] Comparative Example 4:

[0087] Compared with Example 1, the difference is that: the functional compound solvent used in step (1) did not contain dipotassium hydrogen phosphate during preparation, and the solvent pH value was neutral (about 7.0); the remaining steps are the same as in Example 1.

[0088] Comparative Example 5:

[0089] Compared with Example 1, the difference is that the timing of sodium chloride addition was changed. In step (1), when the functional compound solvent was added, an additional 15.0 parts by weight of sodium chloride (relative to the process water) was added, so that the solvent was in a high ionic strength environment at the beginning of extraction; in step (4), sodium chloride was not added again, but the mixture was stirred at a constant temperature of 80°C for 25 minutes; the remaining steps were the same as in Example 1.

[0090] Test Example 1:

[0091] 1. Experimental Procedure

[0092] (1) Experimental preparation:

[0093] Accurately weigh valerone standard (purity ≥98%) and store in a desiccator for later use. Prepare the following three solvent systems:

[0094] Blank control group: Deionized water (conductivity <5 μS / cm), labeled as sample W-0.

[0095] Solubilization test group:

[0096] Sample SA: Functionalized compound solvent A prepared according to the proportions in Preparation Example 1.

[0097] Sample SB: Functionalized compound solvent B prepared according to the proportions in Preparation Example 2.

[0098] Sample SC: Functionalized compound solvent C prepared according to the proportions in Preparation Example 3.

[0099] Phase change test group (solvent in the solubilizing test group):

[0100] Sample PA: Take 100 mL of the above solvent A, add 15.0 g of sodium chloride, stir to dissolve, corresponding to the process conditions of Example 1.

[0101] Sample PB: Take 100 mL of the above solvent B, add 12.0 g of sodium chloride, stir to dissolve, corresponding to the process conditions of Example 2.

[0102] Sample PC: Take 100 mL of the above solvent C, add 15.0 g of sodium chloride, stir to dissolve, corresponding to the process conditions in Example 3.

[0103] (2) Take seven 250mL stoppered conical flasks and add 50.0mL of each of the above-mentioned solvents to each flask. Add an excess of valerone standard (about 190mg) to each conical flask to ensure that the solid phase is always present. After sealing, place the conical flasks in a constant temperature water bath shaker.

[0104] (3) Set the water bath temperature to 25℃ and the oscillation frequency to 120rpm. Shake in the dark for 24 hours to reach thermodynamic dissolution equilibrium. Stop oscillation and let stand for 2 hours to allow undissolved oil droplets or solids to float / sediment into layers.

[0105] (4) Analysis and determination: The intermediate layer supernatant was drawn up with a glass syringe and filtered through a 0.22 μm PTFE syringe filter. The first 3 mL of the initial filtrate was discarded, and the subsequent filtrate was collected. 1.0 mL of the filtrate was taken and diluted to 10 mL with chromatographic grade methanol. The concentration of valerone in the filtrate was determined by high performance liquid chromatography (HPLC). The chromatographic conditions were: C18 column (250 mm × 4.6 mm, 5 μm), mobile phase: methanol-water (85:15) for isocratic elution, flow rate: 1.0 mL / min, column temperature: 30 °C, detection wavelength: 254 nm. The concentration of valerone was calculated using the external standard method. Three replicates of each sample were prepared and determined independently.

[0106] 2. Experimental data (see Table 1)

[0107] Table 1: Equilibrium solubility data of valerone in different solvent systems

[0108] Experimental group Sample number Parallel sample 1 (mg / L) Parallel sample 2 (mg / L) Parallel sample 3 (mg / L) Average solubility (mg / L) Blank control group W-0 18.23 19.05 17.94 18.41 Solubilization test group SA 678.42 685.11 672.90 678.81 SB 509.33 515.67 502.89 509.30 SC 841.25 855.40 848.72 848.46 Phase change test group PA 4.05 3.88 4.19 4.04 PB 7.12 6.95 7.28 7.12 PC 3.42 3.65 3.51 3.53

[0109] 3. Experimental Conclusions

[0110] Table 1 and Figure 1 Data shows that the average solubility of valerone in a pure water system (W-0) is 18.41 mg / L, which confirms that this sesquiterpene ketone compound has significant hydrophobic properties. This is also the thermodynamic reason for the large oil-water mass transfer resistance and limited extraction efficiency in the traditional steam distillation process.

[0111] The results of the solubilization test group showed that the functionalized solvent system constructed by introducing sodium xylenesulfonate significantly altered the solubility behavior of valerone. The solubilities of samples SB, SA, and SC reached 509.30 mg / L, 678.81 mg / L, and 848.46 mg / L, respectively. Compared with the blank control group, the solubility increased by approximately 27 to 46 times. The data showed a positive correlation, meaning that the solubilization ability of the system for valerone increased with increasing sodium xylenesulfonate concentration. This indicates that in a compound solvent environment, sodium xylenesulfonate molecules reduce the activity coefficient of the hydrophobic solute through non-covalent interactions, allowing the originally poorly soluble organic molecules to be stably dispersed in the aqueous phase.

[0112] Data from the phase transition test group demonstrated a reversal of system properties. After the addition of sodium chloride, the solubility of valerone in the PA, PB, and PC groups plummeted to the range of 3.53 mg / L to 7.12 mg / L. This value was not only significantly lower than that during the solubilization stage but also lower than the background solubility in pure water (18.41 mg / L). Specifically, the PA and PC groups (15 samples) with higher sodium chloride dosages showed significantly lower final solubility (approximately 3.5-4.0 mg / L) compared to the PB group (12 samples, approximately 7.1 mg / L), indicating a direct correlation between the salt effect intensity and ionic strength.

[0113] The aforementioned data changes confirm the "dynamic solubility reversal" mechanism proposed in this invention: the introduction of a high-concentration strong electrolyte disrupts the solubilizing structure of sodium xylenesulfonate molecules, leading to a loss of affinity for organic molecules in the system. At this point, valerone, originally dissolved in the aqueous phase, is in a state of extreme supersaturation and is forcibly expelled from the aqueous phase under the action of "salting out." This phase separation process, driven by chemical potential, provides a thermodynamic basis for the efficient volatilization and extraction of the target product in subsequent distillation processes.

[0114] Test Example 2:

[0115] 1. Experimental Procedure

[0116] (1) Experimental preparation:

[0117] Standards: Prepare valerone standard (purity ≥98%) and spikenard standard (purity ≥98%).

[0118] Base solvent: Prepare 600 mL of unadjusted pH functionalized compound solvent matrix according to the preparation process of Preparation Example 1 (without adding dipotassium hydrogen phosphate for the time being).

[0119] Reaction vessel: Take three 500mL single-necked round-bottom flasks and label them No. 1, No. 2 and No. 3 respectively.

[0120] (2) Add the above 600 mL of basic solvent evenly to two flasks (300 mL each), and add different chemical reagents to each flask to construct a specific pH environment:

[0121] Acidic control group (bottle 1): Measure 300 mL of the above-mentioned functionalized basic solvent and add it to bottle 1. Add an appropriate amount of phosphoric acid (85% H3PO4) to adjust the pH of the functionalized basic solvent to 5.5±0.1 to simulate the natural slightly acidic environment of plant extract.

[0122] Strong alkaline control group (bottle 2): Measure 300 mL of the above-mentioned functionalized base solvent and add it to bottle 2. Add an appropriate amount of potassium hydroxide solution (10% w / w) to adjust the pH of the functionalized base solvent to 11.0 ± 0.1 to simulate a strongly alkaline environment.

[0123] Invention Implementation Group (Bottle No. 3): 300 mL of the functionalized compound solvent A prepared in Preparation Example 1 was directly measured and added to Bottle No. 3 (pH value is approximately 8.2).

[0124] (3) Accurately add 1.00 g of valerone standard and 1.00 g of spikenard standard to three round-bottom flasks respectively, shake and mix to obtain a simulated solution, then add 45.0 g of sodium chloride to each of the three flasks and stir to dissolve. Add 1.0 g of clean boiling chips to each flask to prevent bumping, and connect the volatile oil analyzer to the reflux condenser respectively. Heat the round-bottom flasks, adjust the heating intensity to keep the solvent in the flasks at a slight boiling state, and maintain the reflux ratio R=0 for total distillation. Stop heating when the volume of the oil phase in the volatile oil analyzer no longer increases, and cool to room temperature.

[0125] (4) Collect the oil phase from each group of volatile oil analyzers, record the total volume of the oil phase, and accurately pipette 0.1 mL, dilute to 10 mL with chromatographic grade methanol and shake well to obtain the distillate sample.

[0126] Residual liquid sample: Filter the residual liquid in the round-bottom flask and take 10 mL of the filtrate. Add 1 mol / L hydrochloric acid solution to the filtrate to adjust the pH to below 2.0 (to reduce the salt-forming spikenard acid to its free acid form). Accurately pipette 1.0 mL of the acidified residual liquid and dilute to 10 mL with chromatographic grade methanol as the residual liquid test sample.

[0127] (5) The concentrations of valerone and spikenard in each group of "distillate test sample" and "residue test sample" were determined by high performance liquid chromatography (HPLC). The chromatographic conditions were the same as in Test Example 1. A standard curve was prepared using standards, and the mass distribution percentage of each component in the distillate and residue was calculated using the external standard method.

[0128] 2. Experimental data (see Table 2)

[0129] Table 2: Mass transfer distribution data of target analytes and impurities under different pH conditions

[0130] Experimental group Component Name Distribution rate in distillate (%) Distribution rate of residual liquid in distillation flask (%) acidic control group Valerone 94.12 2.05 spikenard 82.55 15.12 Strong base control group Valerone 87.18 3.05 spikenard 0.82 97.45 Invention Implementation Group Valerone 93.95 2.33 spikenard 1.25 96.88

[0131] 3. Experimental Conclusions

[0132] Refer to Table 2 and Figure 2 The data intuitively reflects the impact of pH environment on the volatility characteristics of key components of spikenard essential oil.

[0133] In the acidic control group (flask 1), simulating the natural extraction environment (pH 5.5), the distribution rate of the target product valerone in the distillate was 94.12%, while the distribution rate of the impurity spikenard acid reached 82.55%. This result indicates that under slightly acidic conditions, spikenard acid mainly exists in a free molecular form. Due to its certain vapor pressure, it undergoes azeotropic distillation with valerone during steam distillation, leading to an increase in the acid value and deterioration of the odor in the essential oil product.

[0134] In the invention embodiment group (bottle No. 3), using the functionalized compound solvent A (pH 8.2) of this invention, the distillation behavior of valerone was not significantly inhibited, and the distribution rate remained at 93.95%. In stark contrast, the distribution rate of spikenard acid in the distillate plummeted to 1.25%, while 96.88% of its mass remained in the distillation flask residue. This confirms that under a weakly alkaline buffer system, spikenard acid reacts with dipotassium hydrogen phosphate to form a non-volatile potassium salt, which is effectively retained in the aqueous phase, achieving in-situ separation of impurities.

[0135] In the strong alkaline control group (bottle 2) (pH 11.0), although the retention effect of spikenard acid (residual liquid distribution rate 97.45%) was slightly better than that of the invention group, the recovery rate of the target compound valerone decreased significantly to 87.18%. This indicates that the strong alkaline environment induces chemical degradation or side reactions of ketone compounds, leading to a loss in the yield of the target product. Therefore, the weakly alkaline buffer system selected in this invention is the optimal process range that ensures the removal of acidic impurities while maximizing the maintenance of the chemical stability of the target product.

[0136] Test Example 3:

[0137] 1. Experimental Procedure

[0138] (1) Collect the finished spikenard oil products prepared in Examples 1-3 and Comparative Examples 1, 2, 3 and 5, as well as the corresponding raw spikenard powder.

[0139] (2) Weigh each group of spikenard oil products on a precision electronic balance and record the net mass of spikenard oil. Calculate the total yield of spikenard oil based on the amount of raw materials fed in each example and comparative example (all are solid-liquid ratio conversions under the corresponding solvent volume ratio).

[0140] (3) Accurately pipette about 50 mg of each essential oil sample into a 10 mL volumetric flask, add chromatographic grade n-hexane containing 1.0 mg / mL n-hexadecane (internal standard) to dissolve and dilute to the mark, shake well and filter through a 0.45 μm organic filter membrane to obtain the test solution.

[0141] (4) Quantitative analysis was performed using gas chromatography-mass spectrometry (GC-MS). The chromatographic column was an HP-5MS quartz capillary column (30m×0.25mm×0.25μm), the injection port temperature was 250℃, and the split ratio was 50:1. The temperature program was set as follows: initial temperature 60℃, hold for 2 minutes, increase to 180℃ at a rate of 5℃ / min, and then increase to 280℃ at a rate of 20℃ / min and hold for 5 minutes. The mass spectrometer ion source temperature was 230℃, the quadrupole temperature was 150℃, and the SIM selected ion scanning mode was used to lock the characteristic ions of valerone (m / z 207,105,91).

[0142] (5) Calculate the mass fraction (mg / g) of valerone in each group of essential oils according to the internal standard method, and convert the actual extraction yield of valerone in the raw material (mg / kg, i.e. the number of milligrams of valerone extracted per kilogram of raw material) by combining the total yield of spikenard essential oil. Each group of samples was measured in parallel 3 times and the average value was taken.

[0143] 2. Experimental data (see Table 3)

[0144] Table 3: Data on the yield of spikenard oil and recovery of target substances under different process conditions

[0145] Experimental group Total essential oil yield (%) Valerone content in the finished product (mg / g) Valerone extraction yield (mg / kg) Example 1 2.15 385.42 8286.5 Example 2 1.98 362.15 7170.6 Example 3 2.31 398.67 9209.3 Comparative Example 1 0.62 125.33 777.0 Comparative Example 2 0.75 141.20 1059.0 Comparative Example 3 0.12 85.40 102.5 Comparative Example 5 0.58 118.65 688.2

[0146] 3. Experimental Conclusions

[0147] Table 3 shows that, using a sodium xylenesulfonate-assisted solubilization and sodium chloride phase transition-induced coupling process in Examples 1 to 3, the total essential oil yield was 1.98%-2.31%, and the valerone extraction yield was 7170.6-9209.3 mg / kg. Compared with the traditional steam distillation process in Comparative Example 1 (essential oil yield 0.62%, valerone yield 777.0 mg / kg), the method of this invention significantly improved the extraction efficiency of poorly soluble sesquiterpene ketones. This indicates that in a pure aqueous medium, the target product is difficult to release effectively due to solid-liquid mass transfer resistance, and constructing a functionalized solvent system is key to improving the extraction rate.

[0148] In Comparative Example 2, sodium xylenesulfonate was removed. Although its valerone yield (1059.0 mg / kg) was higher than that of the pure water control group, it was much lower than that of the Example group. This data confirms that sodium xylenesulfonate is the main solubilizing component in the system, which increases the solubility of organic molecules in the aqueous phase through non-covalent interactions.

[0149] Comparative Example 3, which did not undergo a phase change induction step, resulted in a decrease in the essential oil yield to 0.12% and a valerone yield of only 102.5 mg / kg. This result indicates that the micelle structure formed by sodium xylenesulfonate possesses high thermodynamic stability. Without the addition of a strong electrolyte to disrupt this stable system, the target product solubilized in the aqueous phase is difficult to release effectively and distill off with steam. In other words, while a single solubilization operation achieves solid-liquid extraction, it hinders subsequent liquid-gas mass transfer.

[0150] Comparative Example 5 altered the timing of sodium chloride addition, introducing a high concentration of electrolyte at the initial stage of extraction. Its valerone yield (688.2 mg / kg) was lower than that of the pure water extraction group. This indicates that under high ionic strength conditions, the salting-out effect of the electrolyte inhibits the solubilizing activity of sodium xylenesulfonate, causing the solvent system to lose its solubilizing ability for the target molecule during the extraction stage.

[0151] In summary, the experimental data verified the thermodynamic mechanism of the process of this invention: firstly, the solubilizing effect of sodium xylenesulfonate is used to overcome the solid-liquid mass transfer resistance and transfer the target product to the liquid phase; then, sodium chloride is used to adjust the ionic strength to disrupt the solubilization equilibrium and induce a supersaturated state in the system, thereby achieving efficient extraction of the target product during the distillation stage.

[0152] Test Example 4:

[0153] 1. Experimental Procedure

[0154] (1) The spikenard oil products prepared in Examples 1-3 and Comparative Examples 1 and 4 were collected.

[0155] (2) According to GB / T 14455.5-2008 "Determination of Acid Value or Acid Content of Fragrance", accurately weigh about 1.5g of each group of essential oil samples, place them in a 250mL Erlenmeyer flask, add 15mL of neutral ethanol (95%) and 3 drops of 10g / L phenolphthalein ethanol indicator solution, shake well to dissolve the essential oil, and obtain the test solution; use the standardized 0.1mol / L potassium hydroxide-ethanol standard solution to titrate the test solution, continuously shake the Erlenmeyer flask during the titration until the test solution turns pink and remains pink for 30 seconds, record the volume of potassium hydroxide-ethanol standard solution consumed, perform three parallel determinations and take the average value, calculate the acid value (mg KOH / g).

[0156] (3) The content of piracetic acid was determined by high performance liquid chromatography (HPLC). 50 mg of each essential oil was accurately pipetted, dissolved in chromatographic grade methanol and diluted to 10 mL, and filtered through a 0.22 μm organic microporous membrane. A C18 column (250 mm × 4.6 mm, 5 μm) was used as the chromatographic column. The mobile phase was acetonitrile-0.1% phosphoric acid aqueous solution for gradient elution. The flow rate was set to 1.0 mL / min, the detection wavelength was 235 nm, and the column temperature was maintained at 30 °C. The mass percentage of piracetic acid in the essential oil was calculated using the external standard method.

[0157] (4) In accordance with GB / T 14454.4-2008 and GB / T 11540-2008 standards, using an Abbe refractometer (measuring range 1.3000-1.7000, accuracy ±0.0002) and a digital oscillating tube densitometer (measuring accuracy ±0.001 g / cm³), the following measurements were taken: 3 The refractive index of each group of essential oils was measured under a constant temperature of 20℃. ) and relative density ( ).

[0158] 2. Experimental data (see Table 4)

[0159] Table 4: Physicochemical properties and acidic impurity content of spikenard oil under different processing conditions

[0160] Experimental group Acid value (mg KOH / g) spike acid content (%) Refractive index ( ) relative density ( ) Example 1 2.45 0.32 1.4925 0.9412 Example 2 1.89 0.24 1.4918 0.9398 Example 3 3.12 0.45 1.4931 0.9425 Comparative Example 1 28.65 13.56 1.5042 0.9685 Comparative Example 4 24.33 11.08 1.5015 0.9652

[0161] 3. Experimental Conclusions

[0162] Table 4 shows that the acid values ​​of the essential oils obtained in Examples 1 to 3 ranged from 1.89 to 3.12 mg KOH / g, with a residual amount of 0.24% to 0.45% of aridazine. In contrast, Comparative Example 1, extracted with pure water, had an acid value of 28.65 mg KOH / g and an aridazine content of 13.56%; Comparative Example 4, using an unadjusted neutral functional solvent, had an acid value of 24.33 mg KOH / g and an aridazine content of 11.08%.

[0163] Experimental results show that the pH value of the extraction medium directly affects the mass transfer distribution of acidic components. In the slightly acidic and neutral environments of Comparative Examples 1 and 4, spikenard acid molecules mainly exist in the form of protonated free acid. This form is hydrophobic and evaporates with water vapor into the condensate during distillation, leading to an increase in the content of acidic impurities in the distillate. Data from Comparative Example 4 confirms that while using sodium xylenesulfonate alone to solubilize improves mass transfer efficiency, it lacks the ability to selectively distinguish between the target product and acidic impurities.

[0164] In Examples 1-3, the pH of the solvent was stabilized between 8.0 and 8.5 by adding dipotassium hydrogen phosphate. Under these conditions, arisaemacid reacts with the alkali to form ionized potassium arisaemanate. This salt is highly hydrophilic and non-volatile, remaining in the aqueous phase at the bottom of the distillation vessel and not distilled off with the oil-gas mixture.

[0165] The physicochemical constants measurements showed that the refractive index and relative density values ​​of Comparative Examples 1 and 4 were higher than those of the Example Group. This indicates that the incorporation of a large amount of high-boiling-point acidic components altered the physical properties of the essential oil. This invention uses a chemical reaction to fix acidic impurities in the aqueous phase, ensuring that the physical constants of the finished essential oil conform to the standard characteristics of a product primarily composed of sesquiterpene ketones.

[0166] Test Example 5:

[0167] 1. Experimental Procedure

[0168] (1) The spikenard essential oil products prepared in Examples 1-3 were selected as the invention group samples, and the essential oils prepared in Comparative Example 1 (pure water extraction) and Comparative Example 4 (neutral solvent extraction) were selected as the control group samples.

[0169] (2) A sensory evaluation team consisting of 7 professional perfumers with more than 5 years of experience in evaluating natural fragrances was formed. The evaluation environment was set as an independent room with a room temperature of 22°C, a relative humidity of 50%, and no odor.

[0170] (3) Use 0.5cm wide professional scent paper, mark the sample number (blind test using 3-digit random number code), immerse the scent paper in the essential oil sample for about 1.0cm, take it out and let it stand in the air for 60 to 120 seconds; observe that the essential oil on the surface of the scent paper has completely penetrated into the paper fiber, there is no reflective liquid film on the paper surface and the edge of the oil spot no longer spreads outward, it is considered that the diffusion has reached a stable state, and then smell identification is performed.

[0171] (4) The evaluation index is set in four dimensions: characteristic aroma of spikenard (mainly referring to the warm woody and medicinal aroma brought by sesquiterpene ketones), rancid odor (mainly referring to the pungent acidic odor brought by low fatty acids or free acids), burnt odor (referring to the burnt odor produced by high temperature pyrolysis), and overall acceptability. Each dimension is scored on a scale of 0-10, where 0 indicates that the odor is absent or unacceptable, and 10 indicates that the odor is extremely strong or extremely perfect.

[0172] (5) Each evaluator independently scores each sample in two rounds of olfactory identification, with a 30-minute interval between the two rounds to eliminate olfactory fatigue. The final sensory score of the sample is the average score of all evaluators.

[0173] 2. Experimental data (see Table 5)

[0174] Table 5: Sensory aroma profile scores of spikenard oil under different processing conditions

[0175] Experimental group Characteristic aroma of spikenard rancid odor Burnt smell Overall acceptance Example 1 8.8 0.8 0.5 9.2 Example 2 8.5 1.1 0.6 8.8 Example 3 8.9 0.7 0.4 9.0 Comparative Example 1 5.4 8.2 3.5 4.1 Comparative Example 4 7.6 7.5 0.9 5.8

[0176] 3. Experimental Conclusions

[0177] Table 5 shows that the overall acceptability of the essential oils in Examples 1 to 3 was 8.8-9.2 points, the characteristic aroma score of spikenard was 8.5-8.9 points, and the rancid odor score was 0.7-1.1 points. Comparative Example 1 had an overall acceptability of 4.1 points, a rancid odor score of 8.2 points, and a burnt odor score of 3.5 points. Comparative Example 4 had an overall acceptability of 5.8 points, a rancid odor score of 7.5 points, and a burnt odor score of 0.9 points.

[0178] Sensory evaluation results reflect the influence of different process parameters on the aroma components of essential oils. Comparative Example 1, which uses traditional water extraction, showed a high score for rancid odor, indicating that volatile acidic components in the raw material entered the finished product with the water vapor; its high score for burnt odor reflects the thermal degradation of plant fibers during prolonged high-temperature distillation.

[0179] Data from Comparative Example 4 showed that after using a neutral functionalized solvent, the burnt odor score decreased to 0.9, close to that of the Example group. This indicates that the functionalized solvent improved mass transfer efficiency, shortened extraction time, or improved heating uniformity, thereby reducing the generation of heat-sensitive burnt odor. However, the rancid odor score of Comparative Example 4 (7.5) remained high, with no significant difference from Comparative Example 1. This result confirms that simply improving the physical mass transfer properties of the solvent without adjusting the pH value cannot remove volatile acidic odor-causing substances.

[0180] Examples 1-3, by introducing an alkaline buffer into the solvent, controlled the rancidity score to 1.1 or below, while maintaining a low burnt odor score. This indicates that the process of the present invention fixes acidic impurities through chemical reaction and reduces thermal degradation through efficient solubilization, thereby improving the sensory quality of the finished product.

[0181] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for the targeted preparation of spikenard essential oil rich in valerone, characterized in that, Includes the following steps: S1. Take the functionalized compound solvent, add the crude nardostachys chinensis powder according to the liquid-solid ratio, stir and soak to obtain a solid-liquid mixture; the components of the functionalized compound solvent include process water, sodium xylenesulfonate, dipotassium hydrogen phosphate and polyethylene glycol 400; S2. Steam is introduced into the solid-liquid mixture to heat it and maintain a slight boil, and the first stage of distillation is carried out to remove the low-boiling-point components distilled off, thereby obtaining the residue in the vessel. S3. Cool the contents of the reactor to a constant temperature, add sodium chloride and stir until dissolved to obtain a heterogeneous mixed system; S4. Heat the heterogeneous mixture to perform a second-stage distillation and collect the distillate; S5. Separate the distillate from the water and collect the oil phase to obtain the finished spikenard oil.

2. The process for targeted preparation of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S1, the functionalized compound solvent comprises the following components in parts by weight: Process water: 100 parts by weight; Sodium xylenesulfonate: 8.0-12.0 parts by weight; Dipotassium hydrogen phosphate: 1.0-1.5 parts by weight; Polyethylene glycol 400: 0.3-0.5 parts by weight.

3. The targeted preparation process of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S1, the pH value of the functionalized compound solvent is 8.0-8.5; The preparation method of the functionalized compound solvent is as follows: process water is placed under stirring, and sodium xylenesulfonate, dipotassium hydrogen phosphate and polyethylene glycol 400 are added in sequence and stirred until completely dissolved.

4. The targeted preparation process of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S1, the particle size of the coarse Nardostachys jatamansi powder is 20 to 40 mesh, and the moisture content is 8.0% to 12.0%; the liquid-solid ratio is (8-10):1, which is the ratio of the total mass of the functional compound solvent to the mass of the coarse Nardostachys jatamansi powder.

5. The targeted preparation process of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S1, the temperature of the stirring and soaking is 20-30℃, and the time is 1.5-2.5 hours.

6. The process for targeted preparation of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S2, the heating temperature of the first stage distillation is 98-102℃, the reflux ratio R of the distillation column is set to 0.5-1.0, and the distillation duration is 1.5-2.0 hours.

7. The process for targeted preparation of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S3, the constant temperature after cooling is 75-85℃.

8. The process for targeted preparation of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S3, the amount of sodium chloride added is 12.0-15.0 parts by weight, which is relative to the number of parts by weight of process water in the functionalized compound solvent. The stirring time until dissolved is 20-30 minutes.

9. The process for targeted preparation of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S4, the heating temperature of the second stage distillation is 102-105℃, the reflux ratio R is set to 0, and full recovery is carried out; the distillate is collected for 2.5-4.0 hours, or until no obvious oil droplets flow out of the condenser outlet.

10. The process for targeted preparation of valerone-rich spikenard essential oil according to claim 1, characterized in that, In step S5, the oil-water separation operation is as follows: the distillate is allowed to stand in an oil-water separator for 30-60 minutes to separate into layers, and the upper oil phase is obtained; 5%-10% of anhydrous sodium sulfate is added to the upper oil phase for drying, and after filtration, the spikenard essential oil product is obtained.

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