Traditional Chinese medicine preparation method by mechanical pulverization, probiotic fermentation and membrane separation drying

Abstract

The present application relates to the technical field of traditional Chinese medicine preparation, and discloses a traditional Chinese medicine preparation method of mechanical crushing, probiotic fermentation and membrane separation drying. The method comprises the following steps: mixing traditional Chinese medicinal materials with water after mechanical crushing to prepare slurry, and obtaining fermentation medium through sterilization treatment; inoculating probiotic strains into the fermentation medium to obtain fermentation mixture through fermentation conversion; sequentially performing ceramic microfiltration membrane tangential flow filtration and nanofiltration membrane concentration on the fermentation mixture, and then performing supercritical carbon dioxide assisted spray freeze drying to obtain a probiotic fermented traditional Chinese medicine composition. The method increases the specific surface area of medicinal materials to promote the dissolution of active ingredients; probiotic fermentation converts macromolecules into small molecule active substances to improve bioavailability; two-stage membrane separation removes bacteria and impurities at room temperature and concentrates, avoiding the degradation of heat-sensitive components; supercritical carbon dioxide assisted spray freeze drying utilizes low-temperature nitrogen instantaneous freezing and supercritical fluid extraction of water, and the obtained microparticles are loose and porous, and the retention rate of active ingredients is high.

Description

Technical Field

[0001] This invention relates to the field of traditional Chinese medicine preparation technology, and in particular to a method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation and membrane separation drying. Background Technology

[0002] This section is intended to provide background or context for the embodiments of the invention as described in the claims. Nothing in this section should be construed as prior art simply because it is included herein.

[0003] Probiotic fermentation technology for traditional Chinese medicine enhances the bioavailability of active ingredients through microbial transformation. Its industrial preparation typically includes processes such as pulverization, extraction, sterilization, inoculation and fermentation, separation and purification, and drying. Among these, the separation and drying stages directly determine the final product's activity retention rate, product form, and production efficiency.

[0004] Currently, centrifugation or plate and frame filtration are commonly used to separate post-fermentation mixtures. Centrifugation relies on the density difference between the solid and liquid phases, making it difficult to effectively remove submicron-sized bacterial fragments and fine suspended particles, resulting in limited clarity of the separated liquid. The resulting clarified liquid is often concentrated under reduced pressure to reduce the subsequent drying load. This process, occurring continuously at high temperatures, can easily cause partial degradation of heat-sensitive active ingredients such as polysaccharides and saponins produced during fermentation. The drying process often employs freeze-drying or spray drying. Freeze-drying, performed at low temperatures, is beneficial for retaining heat-sensitive components, but the drying cycle can last for over twenty hours, resulting in significant equipment investment and energy consumption. Furthermore, intermittent operation across multiple batches limits production efficiency. Spray drying allows for continuous operation with a short drying time, but the liquid needs to evaporate moisture instantaneously in a high-temperature airflow, with inlet air temperatures often exceeding 150 degrees Celsius. This can also lead to a decrease in the activity of some heat-sensitive substances, and the resulting product is a fine powder that is easily hygroscopic. In the same drying process, if the separated liquid containing active ingredients is concentrated before drying, there are multiple phase changes in the whole process. The thermal history and exposure time of the active ingredients are accumulated, making it difficult to optimize the product activity retention rate and batch-to-batch consistency in a coordinated manner.

[0005] Therefore, it is necessary to design a method for preparing traditional Chinese medicine that combines mechanical pulverization, probiotic fermentation, and membrane separation drying, so as to facilitate low-temperature and efficient separation and drying of fermentation mixtures, improve the retention rate of heat-sensitive active ingredients, and shorten drying time. Summary of the Invention

[0006] To address the above issues and overcome the shortcomings of existing technologies, this invention provides a method for preparing traditional Chinese medicine using mechanical pulverization, probiotic fermentation, and membrane separation drying. This method enables low-temperature, high-efficiency separation and drying of fermentation mixtures, improving the retention rate of heat-sensitive active ingredients and shortening drying time.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing traditional Chinese medicine using mechanical pulverization, probiotic fermentation, and membrane separation drying includes the following steps: S100: The Chinese medicinal materials are mechanically pulverized and mixed with water to form a slurry, which is then sterilized to obtain a fermentation culture medium; S200: Inoculate the fermentation medium with probiotic strains and carry out fermentation to obtain a fermentation mixture; S300: The fermentation mixture is subjected to membrane separation and drying to obtain a probiotic fermented traditional Chinese medicine composition.

[0008] Furthermore, the Chinese medicinal materials mentioned in step S100 are composed of the following raw materials in parts by weight: Astragalus membranaceus 30-50 parts; 10 to 20 portions of Codonopsis pilosula; Angelica sinensis 10-15 parts; 10 to 15 parts goji berries; 10 to 20 servings of jujubes.

[0009] Furthermore, step S100 includes the following steps: S110: The Chinese medicinal materials are crushed and sieved to obtain powder with a particle size of no more than 180 micrometers; S120: Mix the powder and water at a mass ratio of 1:8 to 1:15.

[0010] Furthermore, step S120 includes the following steps: S121: The mechanically pulverized Chinese medicinal materials are placed in an ultrasonic field with a power of 100 watts to 300 watts and pretreated with a complex enzyme of cellulase and pectinase. S122: Mix the pretreated powder with water.

[0011] Furthermore, the sterilization described in step S100 is high-pressure steam sterilization at 115℃~121℃ for 15 minutes to 30 minutes.

[0012] Furthermore, the probiotics mentioned in step S200 are at least one of Lactobacillus plantarum, Lactobacillus rhamnosus, and Bifidobacterium longum, and the inoculation amount is 3% to 8% of the volume of the fermentation medium.

[0013] Furthermore, the fermentation described in step S200 is converted to constant temperature fermentation at 32℃~37℃ for 36 hours~60 hours.

[0014] Furthermore, the membrane separation described in step S300 is a two-stage membrane separation, specifically including: S310: The fermentation mixture is pumped into a ceramic microfiltration membrane module, wherein the ceramic microfiltration membrane has a pore size of 0.2 micrometers to 0.5 micrometers, and the microfiltration permeate is collected in tangential flow filtration mode to retain bacterial cells and suspended particles. S320: The microfiltration permeate is pumped into a nanofiltration membrane module, the nanofiltration membrane having a molecular weight cutoff of 200 Daltons to 1000 Daltons, and then concentrated to obtain a concentrate. in, A pressure sensor is provided at the feed end of the ceramic microfiltration membrane module. A controller adjusts the speed of the feed pump according to the transmembrane pressure signal detected by the pressure sensor to maintain the membrane surface flow rate within a preset range, and the retentate of the nanofiltration membrane module is partially returned to its feed side.

[0015] Furthermore, the drying process described in step S300 is supercritical carbon dioxide-assisted spray freeze drying, specifically as follows: S330: The concentrated liquid is atomized and sprayed through a gas-liquid two-phase flow nozzle into a low-temperature nitrogen atmosphere with a temperature of -40℃ to -20℃ to form frozen microdroplets; S340: Inject supercritical carbon dioxide fluid at a temperature of 32℃~40℃ and a pressure of 10 MPa~20 MPa into the chamber where the frozen microdroplets are located, so that the supercritical carbon dioxide fluid and the frozen microdroplets are in countercurrent contact and extract water, for a period of 30 minutes~90 minutes, to obtain dried probiotic fermented Chinese medicine composition microparticles. in, The supercritical carbon dioxide fluid carrying moisture is depressurized to subcritical pressure through a throttling valve and enters a gas-liquid separator to separate liquid water. The separated carbon dioxide gas is pressurized to 10 MPa to 20 MPa by a compressor, and then the temperature is adjusted to 32°C to 40°C by a heat exchanger before returning to the chamber for recycling. Furthermore, multiple temperature sensors are arranged axially within the chamber, and a controller adjusts the supply flow rate of cryogenic nitrogen based on the temperature signals fed back by the temperature sensors, so as to maintain the temperature of the frozen microdroplets at -40℃ to -20℃.

[0016] Furthermore, the mass flow rate of the supercritical carbon dioxide fluid is 5 kg / h to 15 kg / h per kilogram of concentrate.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a mechanical pulverization process to process medicinal herbs to a suitable particle size, increasing the contact area between the herbs and water, which facilitates the subsequent dissolution of active ingredients and microbial utilization. It also utilizes membrane separation and drying processes to separate and dry the fermentation mixture at low temperatures. Overall, this invention enables continuous operation of pulverization, fermentation, separation, and drying in the preparation of fermented medicinal herb compositions, balancing separation efficiency with the retention of active ingredients.

[0018] This invention uses specific weight proportions of Chinese medicinal herbs to optimize the carbon and nitrogen source composition of the fermentation culture medium, providing a balanced nutritional environment for probiotics.

[0019] This invention uses ultra-fine grinding and a specific material-to-water ratio to prepare the slurry, which can improve the uniformity of dispersion of medicinal powder in water and control the initial dissolved oxygen and osmotic pressure of the culture medium, which is conducive to the rapid proliferation of strains after inoculation.

[0020] This invention introduces ultrasonic field-assisted compound enzymatic hydrolysis pretreatment after mechanical pulverization. The cavitation effect of ultrasound can be used to promote the mass transfer and penetration of cellulase and pectinase into the cell wall of medicinal materials, improve the enzymatic hydrolysis efficiency of cell wall polysaccharides, and release more intracellular active ingredients.

[0021] This invention employs a high-pressure steam sterilization process and limits temperature and time parameters, which can effectively inactivate bacteria while reducing excessive loss of heat-sensitive components.

[0022] This invention uses a specific combination of strains and a limited inoculation amount to establish a dominant microbial community in the early stage of fermentation and inhibit the growth of miscellaneous bacteria.

[0023] This invention specifies the temperature and time parameters for constant-temperature fermentation, which allows probiotics to fully metabolize during the logarithmic growth phase and promotes the biotransformation of active ingredients in medicinal materials.

[0024] This invention employs a two-stage membrane separation process. A ceramic microfiltration membrane is used for tangential flow filtration to retain bacteria and suspended particles, resulting in a highly clear microfiltration permeate. A nanofiltration membrane is used for low-temperature concentration, avoiding the degradation of active ingredients caused by heating during concentration. Simultaneously, a pressure sensor at the feed end of the ceramic microfiltration membrane module and a controller regulate the feed pump speed to maintain a stable membrane flow rate, mitigating membrane fouling and extending continuous operating time. Partial recirculation of the retentate from the nanofiltration membrane module improves the recovery rate of the target active ingredient.

[0025] This invention employs supercritical carbon dioxide-assisted spray freeze-drying. The concentrated liquid is atomized and sprayed through a gas-liquid two-phase flow nozzle into a low-temperature nitrogen atmosphere to form frozen microdroplets. This enables rapid freeze-drying and shaping of the liquid, avoiding the damage to the microstructure caused by prolonged ice crystal growth. Under low-temperature conditions, water is extracted through countercurrent contact between supercritical carbon dioxide and the frozen microdroplets, shortening the drying time and reducing the degradation of heat-sensitive active ingredients during the drying process. The supercritical carbon dioxide is recycled after throttling, depressurization, gas-liquid separation, compression, and heat exchange for temperature regulation, reducing solvent consumption. Multiple temperature sensors are axially spaced within the chamber, and the low-temperature nitrogen supply flow rate is adjusted by a controller to maintain the frozen microdroplets within a predetermined temperature range, ensuring the stability of the drying process and product consistency.

[0026] This invention limits the mass flow rate range of supercritical carbon dioxide fluid, which can ensure the water extraction rate while preventing excessive mass flow rate from causing frozen droplet entrainment or temperature fluctuations. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart illustrating the preparation method of traditional Chinese medicine involving mechanical pulverization, probiotic fermentation, and membrane separation drying. Detailed Implementation

[0029] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Moreover, the various specific examples of processes and materials provided in this invention are examples of applications of other processes and / or the use of other materials that will be apparent to those skilled in the art.

[0035] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] This invention discloses a method for preparing traditional Chinese medicine through mechanical pulverization, probiotic fermentation, and membrane separation drying. The method includes the following steps: S100: The Chinese medicinal materials are mechanically pulverized and mixed with water to form a slurry, which is then sterilized to obtain a fermentation culture medium; The mechanical pulverization process serves to break down the medicinal herbs into fine particles through shearing and impact, increasing the surface area of ​​contact between the herbs and water. This facilitates the dissolution of active ingredients and microbial transformation during subsequent fermentation. This mechanical pulverization process can be performed using a hammer mill or an air jet mill. The selected medicinal herbs are fed into the pulverizing chamber, where they are broken down to the target particle size range by high-speed rotating hammers or high-speed airflow. In this embodiment, a hammer mill is used, with a screen aperture matching the target particle size; in other embodiments, a ball mill, vibratory mill, or turbine mill can also be used.

[0037] In step S100, the Chinese medicinal materials consist of the following raw materials in parts by weight: Astragalus membranaceus 30-50 parts; Codonopsis pilosula 10-20 parts; Angelica sinensis 10-15 parts; Lycium barbarum 10-15 parts; Jujube 10-20 parts.

[0038] The above-mentioned ingredients work synergistically to form a compound formula, providing a balanced carbon and nitrogen source for probiotics. Simultaneously, the active ingredients inherent in the herbs themselves form the functional basis of the product. Astragalus membranaceus, the dried root of *Astragalus mongholicus* or *Astragalus membranaceus* (Fabaceae family), is rich in astragalus polysaccharides and astragaloside A. In the compound formula, it serves as the principal ingredient, providing the main effects of tonifying qi and strengthening the exterior. Codonopsis pilosula, the dried root of *Codonopsis pilosula* (Camptotheca family), contains codonopsis polysaccharides and codonopsis glycosides, synergistically enhancing the body's immune function with Astragalus membranaceus. Angelica sinensis, the dried root of *Angelica sinensis* (Apiaceae family), contains ferulic acid and angelica polysaccharides, and has the effect of nourishing and activating blood circulation. Lycium barbarum, the dried mature fruit of *Lycium barbarum* (Solanaceae family), contains lycium polysaccharides and betaine, and also has the effect of nourishing the liver and kidneys. Ziziphus jujuba, the dried mature fruit of *Ziziphus jujuba* (Rhamnaceae family), contains ziziphus jujuba polysaccharides and cyclic adenosine monophosphate, harmonizing the other ingredients and improving the taste. In this embodiment, 40 parts of Astragalus membranaceus, 15 parts of Codonopsis pilosula, 12 parts of Angelica sinensis, 12 parts of Lycium barbarum, and 15 parts of Ziziphus jujuba can be weighed as the proportion. In other embodiments, a proportion of 30 parts of Astragalus membranaceus, 20 parts of Codonopsis pilosula, 10 parts of Angelica sinensis, 15 parts of Lycium barbarum, and 10 parts of Ziziphus jujuba, or a proportion of 50 parts of Astragalus membranaceus, 10 parts of Codonopsis pilosula, 15 parts of Angelica sinensis, 10 parts of Lycium barbarum, and 20 parts of Ziziphus jujuba can be selected. Before weighing, each raw material is sorted to remove impurities, mud, sand, and non-medicinal parts, and washed with water and dried at a low temperature below 60°C until the moisture content does not exceed 10%, and then pulverized.

[0039] Specifically, step S100 includes S110 and S120.

[0040] S110: The medicinal materials are pulverized and sieved to obtain powder with a particle size not exceeding 180 micrometers. The sieving process is used to classify the pulverized powder by particle size, ensuring the uniformity of particle size distribution, thereby guaranteeing the suspension stability of the slurry when mixed with water. The sieving device used can be a vibrating screen or a rotary vibrating screen, with the screen mesh number matching the target particle size. In this embodiment, a universal pulverizer is used for mechanical pulverization, and the powder is sieved through an 80-mesh sieve to obtain powder with a particle size not exceeding 180 micrometers. In other embodiments, a ball mill or an air jet mill can also be used to achieve similar particle size requirements, with the screen mesh number selected between 80 and 200 mesh, and the powder particle size controlled between 75 and 180 micrometers depending on the fiber characteristics of the medicinal materials. Powder with an excessively large particle size is prone to sedimentation and stratification in the slurry, while powder with an excessively fine particle size increases pulverization energy consumption and may increase the tendency for membrane pore blockage during subsequent membrane separation.

[0041] S120: Mix powder and water at a mass ratio of 1:8 to 1:15.

[0042] The control of the water ratio directly determines the initial dissolved oxygen concentration and osmotic pressure of the fermentation medium, affecting the adaptation speed and proliferation initiation of probiotics during the lag phase. The mixed water used is purified water or water for injection, with an electrical conductivity not exceeding 2 μS / cm.

[0043] In this embodiment, the mass ratio of powder to water is 1:10; in other embodiments, when the degree of lignification of the medicinal material is low, a material-to-liquid ratio of 1:8 can also be used, and when the fiber content of the medicinal material is high, a ratio of 1:15 can be used, or a ratio of 1:9, 1:12 or other intermediate values ​​can be selected according to the viscosity of the target fermentation liquid.

[0044] Specifically, step S120 includes S121 and S122.

[0045] S121: The mechanically pulverized Chinese medicinal materials are placed in an ultrasonic field with a power of 100 watts to 300 watts and pretreated with a complex enzyme of cellulase and pectinase.

[0046] The ultrasound-assisted enzymatic hydrolysis pretreatment process utilizes ultrasound to generate cavitation microjets in the liquid phase, promoting the penetration and mass transfer of cellulase and pectinase into the cell wall fiber skeleton of medicinal materials, accelerating the hydrolysis and breakage of cell wall polysaccharides, causing partial disintegration of the cell wall structure, releasing intracellular polysaccharides, saponins and other active ingredients, and improving the accessibility of subsequent fermentation.

[0047] The compound enzyme can be prepared by mixing cellulase and pectinase in a 1:1 mass ratio, and the enzymatic hydrolysis temperature is controlled at 40℃~50℃.

[0048] The ultrasonic field is generated by an immersion ultrasonic transducer, which is arranged on the side wall or bottom of the enzymatic hydrolysis tank.

[0049] In this embodiment, the ultrasonic power is set to 200 watts and the enzymatic hydrolysis time is 30 minutes. In other embodiments, for cases where the proportion of root and rhizome medicinal materials is high, an ultrasonic power of 300 watts can be selected, while for cases where the proportion of leafy medicinal materials is high, the treatment can be carried out under the condition of 100 watts.

[0050] The enzymatic hydrolysis tank is made of 304 stainless steel with a polished inner wall. The tank is equipped with a jacket for temperature control, and circulating hot water is circulated in the jacket to maintain the enzymatic hydrolysis temperature.

[0051] The amount of the compound enzyme added is 0.5% to 2% of the powder mass, and in this example it is 1%.

[0052] S122: Mix the pretreated powder with water.

[0053] The mixing process is carried out in a mixing tank, where the powder is continuously stirred for 10 to 20 minutes at a speed of 60 to 100 rpm using an anchor mixer to fully disperse the powder in the water and form a homogeneous slurry.

[0054] The mixing tank is a vertical cylindrical container with a manhole, inlet, outlet and level gauge interface.

[0055] After mixing, the slurry is transported to the sterilizer via a diaphragm pump or screw pump.

[0056] In this embodiment, the stirring speed is 80 rpm and the stirring time is 15 minutes; in other embodiments, if the slurry viscosity is high, the stirring time can be extended to 20 minutes or the stirring speed can be increased to 100 rpm.

[0057] In addition, in step S100, sterilization is performed by high-pressure steam sterilization at 115℃~121℃ for 15 minutes to 30 minutes.

[0058] The purpose of high-pressure steam sterilization is to use the latent heat of high-temperature saturated steam to denature and coagulate microbial proteins, inactivating the original bacteria and spores in the fermentation medium, and ensuring that the subsequent probiotic fermentation is a pure culture.

[0059] The sterilizer is a pressure vessel equipped with a jacket and a temperature sensor transmitter. Steam is introduced from an external industrial steam source through a pressure reducing valve. The sterilizer is equipped with a quick-opening door and a steam distributor inside to ensure that the steam acts evenly on all parts of the material.

[0060] In this embodiment, the sterilization temperature is set to 121°C, the sterilization time is 20 minutes, and the pressure inside the autoclave is maintained at 0.1~0.15 MPa. In other embodiments, for herbal formulations with high heat sensitivity, the temperature can be appropriately reduced to 115°C and the sterilization time extended to 30 minutes.

[0061] After sterilization, sterile air is introduced into the autoclave through a 0.22-micron sterilization filter to establish a slight positive pressure, preventing the backflow of outside air into the autoclave during the cooling process.

[0062] After sterilization, the fermentation medium is cooled to 32℃~37℃ and then transferred to a fermenter.

[0063] S200: Inoculate probiotic strains into the fermentation medium, carry out fermentation transformation, and obtain a fermentation mixture.

[0064] Step S200 involves introducing the dominant bacterial population into a sterilized culture medium and utilizing the metabolic enzyme system of the microorganisms to convert the macromolecular components in the medicinal materials into smaller, more easily absorbed active substances.

[0065] The fermentation equipment uses a mechanically stirred fermenter with a stirring paddle, temperature jacket and online pH electrode. The tank body is made of 316L stainless steel and the inner surface is mirror polished. The height-to-diameter ratio of the tank body is 2:1 to 3:1.

[0066] The fermenter is equipped with a sterile inoculation port. Before inoculation, the inoculation port is wiped with 75% ethanol and the inoculation operation is completed under flame protection.

[0067] In this embodiment, the effective volume of the fermenter is 100 liters and the liquid filling coefficient is 0.7; in other embodiments, fermenters with specifications ranging from 50 liters to 5000 liters can be selected according to production capacity requirements.

[0068] In addition, in step S200, the probiotic is at least one of Lactobacillus plantarum, Lactobacillus rhamnosus, and Bifidobacterium longum, and the inoculation amount is 3% to 8% of the fermentation medium volume. These three probiotics are all catalog strains that can be used in food and pharmaceuticals, and can be obtained from the China General Microbiological Culture Collection Center. Before inoculation, they need to be progressively expanded in MRS liquid medium to obtain seed liquid in the logarithmic growth phase.

[0069] The optimal growth temperature for Lactobacillus plantarum is 30℃~37℃, and it can produce lactic acid and Lactobacillus plantarum glycosides during metabolism.

[0070] Lactobacillus rhamnosus grows well at 32℃~37℃ and has a strong ability to colonize the intestines.

[0071] Bifidobacterium longum is an obligate anaerobic bacterium. It needs to be cultured in an anaerobic workstation or by introducing nitrogen to maintain an anaerobic environment. The optimal growth temperature is 36℃~38℃.

[0072] In this embodiment, a mixed seed culture of Lactobacillus plantarum and Bifidobacterium longum is used, with an inoculation amount of 5%; in other embodiments, Lactobacillus plantarum can be used alone with an inoculation amount of 3%, or Lactobacillus rhamnosus can be added to form a three-strain combination with an inoculation amount of 8%.

[0073] In step S200, the fermentation process is converted to constant temperature fermentation at 32℃~37℃ for 36 to 60 hours.

[0074] The setting of fermentation temperature and time affects the cell growth rate and the accumulation level of secondary metabolites.

[0075] Circulating water is introduced into the jacket of the fermenter, and the water temperature is controlled by a thermostat to keep the temperature inside the tank within the set value ±0.5℃.

[0076] In this embodiment, the fermentation temperature is 37°C, the fermentation time is 48 hours, the stirring speed is 80 rpm, and the aeration rate is 0.5 liters of sterile air per minute per liter of fermentation liquid. In other embodiments, when the strain is mainly Lactobacillus rhamnosus, the fermentation temperature is controlled at 32°C. When the product viscosity requirement is high, the fermentation time can be extended to 60 hours.

[0077] During fermentation, samples were taken every 6 hours to test the pH value and viable cell count, with the viable cell count reaching 1×10⁻⁶. 9 Colony forming units per milliliter are used as one of the reference indicators for the fermentation endpoint.

[0078] S300: Membrane separation and drying of the fermentation mixture to obtain a probiotic fermented traditional Chinese medicine composition.

[0079] Membrane separation removes bacterial cells, suspended particles, and macromolecular impurities from the fermentation broth, achieving primary purification and concentration of active ingredients; the subsequent drying process converts the concentrate into solid micro powder, facilitating storage and application.

[0080] The membrane separation and drying processes are connected in series via pipelines. After the concentrate is discharged from the nanofiltration membrane module, it is temporarily stored in a buffer tank and then transported to the drying system by a high-pressure pump.

[0081] In this embodiment, the buffer tank is equipped with a jacketed cooling system to maintain the temperature of the concentrate at 4~10°C.

[0082] In step S300, the membrane separation is a two-stage membrane separation, specifically including S310 and S320.

[0083] S310: The fermentation mixture is pumped into a ceramic microfiltration membrane module with a pore size of 0.2 micrometers to 0.5 micrometers. The microfiltration membrane traps bacteria and suspended particles in tangential flow filtration mode and collects the microfiltration permeate.

[0084] The function of ceramic microfiltration membrane modules is to separate solid and liquid phases through pore size sieving mechanism. The membrane material is α-alumina, but it can also be zirconium oxide or titanium oxide. The membrane tube has a single-channel or multi-channel tubular structure, good chemical stability, can withstand online steam sterilization, tolerate pH range of 0~14, and the maximum operating temperature can reach 150℃.

[0085] The tangential flow filtration mode creates a high-speed shear flow of the feed liquid on the membrane surface, which inhibits the accumulation of filter cake.

[0086] In this embodiment, the ceramic microfiltration membrane has a pore size of 0.2 micrometers, an operating pressure of 0.15~0.3 MPa, and a membrane surface flow rate of 3~5 m / s. In other embodiments, when the viscosity of the fermentation broth is high, a microfiltration membrane with a pore size of 0.5 micrometers can be used to maintain the flux, or a microfiltration membrane with a pore size of 0.45 micrometers can be used.

[0087] The microfiltration permeate is collected in an intermediate storage tank.

[0088] S320: The microfiltration permeate is pumped into the nanofiltration membrane module. The nanofiltration membrane has a molecular weight cutoff of 200 Daltons to 1000 Daltons. The solution is then concentrated to obtain a concentrate.

[0089] The function of nanofiltration membrane modules is to use sieving and the Donnan effect to retain effective molecules such as polysaccharides and saponins, while allowing monovalent salts and water molecules to pass through, thereby achieving low-temperature concentration without heating.

[0090] The nanofiltration membrane is made of polyamide composite membrane, or cellulose acetate or polyethersulfone, and is packed in a spiral wound membrane housing. The membrane element is either spiral wound or hollow fiber.

[0091] In this embodiment, the nanofiltration membrane has a molecular weight cutoff of 500 Daltons, an operating pressure of 0.5~1.0 MPa, and a concentration factor controlled at 5~10 times. In other embodiments, if it is desired to improve the retention rate of small molecule active peptides, a nanofiltration membrane with a molecular weight cutoff of 200 Daltons or 300 Daltons can be selected. If the focus is on desalination, a nanofiltration membrane with a molecular weight cutoff of 800 Daltons or 1000 Daltons can be selected.

[0092] The ceramic microfiltration membrane module is equipped with a pressure sensor at the feed end. A controller adjusts the speed of the feed pump based on the transmembrane pressure signal detected by the pressure sensor to maintain the membrane surface flow rate within a preset range.

[0093] The pressure sensor is a piezoresistive transducer that converts the transmembrane pressure into a 4-20 mA current signal, which is then input to the controller. After the controller performs proportional-integral calculations, it adjusts the electrical frequency of the feed pump via a frequency converter, thereby changing the pump speed and output flow rate, maintaining a constant membrane surface velocity, and slowing down the membrane fouling rate.

[0094] The preset range for transmembrane pressure is generally 0.1~0.4 MPa.

[0095] Furthermore, a portion of the retentate from the nanofiltration membrane module is refluxed back to its feed side. The reflux ratio is controlled via a reflux pipeline and a regulating valve to improve the recovery rate of the target active ingredient. The reflux ratio is typically set to 0.3~0.7.

[0096] The controller can be integrated into the electrical control cabinet, which is equipped with a touch screen human-machine interface that can display and record process parameters such as transmembrane pressure, membrane surface flow rate, and pump speed in real time.

[0097] In step S300, the drying is supercritical carbon dioxide-assisted spray freeze drying, specifically steps S330 and S340.

[0098] S330: The concentrated liquid is atomized and sprayed through a gas-liquid two-phase flow nozzle into a low-temperature nitrogen atmosphere with a temperature of -40℃ to -20℃ to form frozen microdroplets.

[0099] The function of the gas-liquid two-phase flow nozzle is to introduce compressed nitrogen as an atomizing medium to shear the concentrate into micron-sized droplets. The droplets are rapidly frozen in a low-temperature nitrogen atmosphere to form frozen microdroplets containing active ingredients encapsulated in a solid ice crystal skeleton.

[0100] The gas-liquid two-phase flow nozzle consists of a liquid phase channel, a gas phase channel, and a mixing chamber. The liquid phase channel is used to transport concentrated liquid, and the gas phase channel is used to introduce compressed nitrogen. The two phases are mixed in the mixing chamber and then ejected from the nozzle orifice. The nozzle orifice is a converging cone shape.

[0101] In this embodiment, the temperature of the concentrate is 4~10℃, the nozzle orifice diameter is 0.7 mm, the atomizing nitrogen pressure is 0.2~0.5 MPa, the low-temperature nitrogen is obtained by vaporizing liquid nitrogen and regulating it through an electric heater, and the temperature of the injection chamber is maintained at -30℃. In other embodiments, the nozzle orifice diameter can be selected in the range of 0.5 mm to 1.0 mm, the low-temperature nitrogen temperature can be adjusted according to the freezing point of the concentrate, for example -20℃ or -40℃, and the gas-liquid mass ratio can be adjusted in the range of 0.3~0.8 to control the particle size distribution of the frozen microdroplets.

[0102] S340: Inject supercritical carbon dioxide fluid at a temperature of 32℃~40℃ and a pressure of 10 MPa~20 MPa into the chamber where the frozen microdroplets are located, so that the supercritical carbon dioxide fluid and the frozen microdroplets are in countercurrent contact and extract water, for a period of 30 minutes~90 minutes, to obtain dried probiotic fermented Chinese medicine composition microparticles.

[0103] The role of supercritical carbon dioxide fluid is to utilize its high diffusion coefficient and low viscosity solvent properties in the supercritical state to penetrate into the gaps between ice crystals of frozen microdroplets, carrying water out in a dissolved state, thereby bypassing the phase change of liquid water and achieving a combination of low-temperature sublimation drying and extraction drying.

[0104] After carrying moisture, the supercritical carbon dioxide fluid is depressurized to subcritical pressure through a throttling valve. The carbon dioxide's ability to dissolve water drops sharply, and the moisture condenses into liquid water in the gas-liquid separator and is discharged. The separated carbon dioxide gas is pressurized to 10-20 MPa by a compressor, and then its temperature is adjusted to 32-40°C by a heat exchanger before returning to the chamber for recycling.

[0105] Meanwhile, multiple temperature sensors are arranged at intervals along the axial direction in the chamber. A controller adjusts the supply flow rate of cryogenic nitrogen based on the temperature signals fed back by the temperature sensors to keep the temperature of the frozen microdroplets at -40℃ to -20℃.

[0106] These temperature sensors are armored thermocouples, with three to five measuring points evenly distributed along the axial direction of the chamber. The controller collects temperature signals through an analog input module, compares the deviation with the set temperature range, and then controls the opening of the electronic flow regulating valve on the cryogenic nitrogen pipeline to form a closed-loop feedback.

[0107] In this embodiment, the supercritical carbon dioxide fluid temperature is 35°C, the pressure is 15 MPa, and the extraction time is 60 minutes. In other embodiments, the extraction time can be extended to 90 minutes or shortened to 30 minutes depending on the target water content requirement of the particles. The supercritical carbon dioxide fluid temperature can be operated at 32°C or 40°C, and the pressure can be selected at 10 MPa or 20 MPa.

[0108] The moisture content of the microparticles at the drying endpoint is controlled at 3% to 8%, and the resulting microparticles have a particle size distribution between 50 micrometers and 200 micrometers. The microparticles are porous spherical or near-spherical, with a bulk density of 0.2 to 0.5 g / mL.

[0109] The purity of recycled carbon dioxide is no less than 99.5%, and losses caused by leakage or other reasons during the recycling process are replenished through carbon dioxide supply bottles.

[0110] The mass flow rate of supercritical carbon dioxide fluid is 5 kg / h to 15 kg / h per kilogram of concentrate. This mass flow rate range is determined based on extraction kinetics experiments. Too low a flow rate will lead to prolonged drying time, while too high a flow rate may cause fluidization entrainment of frozen droplets, affecting the yield.

[0111] In this embodiment, the mass flow rate of the supercritical carbon dioxide fluid is 10 kg / h per kilogram of concentrate; in other embodiments, when the solid content of the concentrate is high, a flow rate of 15 kg / h per kilogram of concentrate can be selected, and when the solid content of the concentrate is low, a flow rate of 5 kg / h or 8 kg / h per kilogram of concentrate can be used.

[0112] The working principle of this invention is roughly as follows: First, the cell wall structure of Chinese medicinal materials is destroyed at both the physical shearing and chemical enzymatic hydrolysis levels through mechanical crushing and ultrasonic-assisted enzymatic hydrolysis, releasing intracellular active ingredients and providing sufficient substrates for subsequent microbial transformation. Next, a single or mixed bacterial system dominated by lactic acid bacteria and bifidobacteria is constructed in the fermenter. Under temperature control, liquid deep fermentation is carried out for tens of hours. The enzyme system produced by the metabolism of the bacteria carries out biotransformation of macromolecules in the medicinal materials, hydrolyzing polysaccharides into oligosaccharides and breaking down proteins into polypeptides, while producing metabolites such as lactic acid and short-chain fatty acids. After fermentation, instead of introducing high-temperature heating, a two-stage membrane module consisting of a ceramic microfiltration membrane and a nanofiltration membrane is connected in series to complete solid-liquid separation and concentration of effective components at room temperature or near room temperature, which greatly reduces the volume of the liquid and removes bacteria and suspended particles. The concentrate then enters a supercritical carbon dioxide-assisted spray freeze-drying system, where the liquid is rapidly frozen into microdroplets using a low-temperature nitrogen atmosphere. The frozen microdroplets are then subjected to countercurrent water extraction using supercritical carbon dioxide fluid, allowing the ice crystals to be removed directly in a dissolved state, without the need for the lengthy process of liquid water evaporation or high-vacuum sublimation required in conventional freeze-drying.

[0113] Throughout the entire preparation process, except for the sterilization step, the materials are kept in a medium-low temperature environment, and the degree of thermal degradation of the heat-sensitive active ingredients is controlled.

[0114] In summary, this application combines mechanical pulverization, ultrasonic-assisted enzymatic hydrolysis, probiotic fermentation, two-stage membrane separation, and supercritical carbon dioxide-assisted spray freeze drying, which to a certain extent enables continuous preparation of low-temperature extraction, room-temperature concentration, and low-temperature drying. It can shorten the overall preparation cycle while maintaining the activity retention rate of heat-sensitive components such as polysaccharides and saponins, and has certain positive effects on the industrial-scale production of probiotic fermented traditional Chinese medicine preparations.

[0115] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of the patent of the present invention.

Claims

1. A method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying, characterized in that, Includes the following steps: S100: The Chinese medicinal materials are mechanically pulverized and mixed with water to form a slurry, which is then sterilized to obtain a fermentation culture medium; S200: Inoculate the fermentation medium with probiotic strains and carry out fermentation to obtain a fermentation mixture; S300: The fermentation mixture is subjected to membrane separation and drying to obtain a probiotic fermented traditional Chinese medicine composition.

2. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 1, characterized in that, The Chinese medicinal materials mentioned in step S100 are composed of the following raw materials in parts by weight: Astragalus membranaceus 30-50 parts; 10 to 20 portions of Codonopsis pilosula; Angelica sinensis 10-15 parts; 10 to 15 parts goji berries; 10 to 20 servings of jujubes.

3. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 2, characterized in that, Step S100 includes the following steps: S110: The Chinese medicinal materials are crushed and sieved to obtain powder with a particle size of no more than 180 micrometers; S120: Mix the powder and water at a mass ratio of 1:8 to 1:

15.

4. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 3, characterized in that, Step S120 includes the following steps: S121: The mechanically pulverized Chinese medicinal materials are placed in an ultrasonic field with a power of 100 watts to 300 watts and pretreated with a complex enzyme of cellulase and pectinase. S122: Mix the pretreated powder with water.

5. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 1, characterized in that, The sterilization described in step S100 is high-pressure steam sterilization at 115℃~121℃ for 15 minutes to 30 minutes.

6. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 1, characterized in that, The probiotics mentioned in step S200 are at least one of Lactobacillus plantarum, Lactobacillus rhamnosus, and Bifidobacterium longum, and the inoculation amount is 3% to 8% of the volume of the fermentation medium.

7. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 6, characterized in that, The fermentation described in step S200 is converted to constant temperature fermentation at 32℃~37℃ for 36 hours~60 hours.

8. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 1, characterized in that, The membrane separation described in step S300 is a two-stage membrane separation, specifically including: S310: The fermentation mixture is pumped into a ceramic microfiltration membrane module, wherein the ceramic microfiltration membrane has a pore size of 0.2 micrometers to 0.5 micrometers, and the microfiltration permeate is collected in tangential flow filtration mode to retain bacterial cells and suspended particles. S320: The microfiltration permeate is pumped into a nanofiltration membrane module, the nanofiltration membrane having a molecular weight cutoff of 200 Daltons to 1000 Daltons, and then concentrated to obtain a concentrate. in, A pressure sensor is provided at the feed end of the ceramic microfiltration membrane module. A controller adjusts the speed of the feed pump according to the transmembrane pressure signal detected by the pressure sensor to maintain the membrane surface flow rate within a preset range, and the retentate of the nanofiltration membrane module is partially returned to its feed side.

9. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 1, characterized in that, The drying process described in step S300 is supercritical carbon dioxide-assisted spray freeze drying, and the specific steps are as follows: S330: The concentrated liquid is atomized and sprayed through a gas-liquid two-phase flow nozzle into a low-temperature nitrogen atmosphere with a temperature of -40℃ to -20℃ to form frozen microdroplets; S340: Inject supercritical carbon dioxide fluid at a temperature of 32℃~40℃ and a pressure of 10 MPa~20 MPa into the chamber where the frozen microdroplets are located, so that the supercritical carbon dioxide fluid and the frozen microdroplets are in countercurrent contact and extract water, for a period of 30 minutes~90 minutes, to obtain dried probiotic fermented Chinese medicine composition microparticles. in, The supercritical carbon dioxide fluid carrying moisture is depressurized to subcritical pressure through a throttling valve and enters a gas-liquid separator to separate liquid water. The separated carbon dioxide gas is pressurized to 10 MPa to 20 MPa by a compressor, and then the temperature is adjusted to 32°C to 40°C by a heat exchanger before returning to the chamber for recycling. Furthermore, multiple temperature sensors are arranged axially within the chamber, and a controller adjusts the supply flow rate of cryogenic nitrogen based on the temperature signals fed back by the temperature sensors, so as to maintain the temperature of the frozen microdroplets at -40℃ to -20℃.

10. The method for preparing traditional Chinese medicine by mechanical pulverization, probiotic fermentation, and membrane separation drying according to claim 9, characterized in that, The mass flow rate of the supercritical carbon dioxide fluid is 5 kg / h to 15 kg / h per kilogram of concentrate.

Images