Preparation method of cyclocarya paliurus leaf polyphenol

Abstract

The application discloses a kind of preparation methods of Cyclocarya paliurus leaf polyphenol, it is related to Cyclocarya paliurus leaf polyphenol preparation field, including S1 raw material acceptance;S2 rough crushing;S3 raw material weighing;S4 hot water extraction;S5 filtration;S6 concentration;S7 spray drying;S8 sieving, packaging;S9 inspection;S10 warehousing;The application is by optimizing hot water / ethanol extraction parameter (hot water liquid ratio 1:10-20 / 1:5-10, ethanol concentration 50-70%), with enzymolysis (total polyphenol is extracted to 24.5g / 100g, increases 3.3%) or ultrasonic auxiliary, improves extraction efficiency, enzymolysis clear compound ratio (cellulase:pectinase=1:1), concentration 0.5-2%, pH 4-5, ultrasonic defined frequency 20-40kHz, power 200-500W, parameter standardization;Ultrasonic uses intermittent mode, avoids local overtemperature, inactivates after enzymolysis treatment, solves the problem of low efficiency, polyphenol destruction.

Description

Technical Field

[0001] This invention relates to the technical field of preparation of *Cyclocarya paliurus* leaf polyphenols, specifically a method for preparing *Cyclocarya paliurus* leaf polyphenols. Background Technology

[0002] Eucommia ulmoides is a medicinal plant whose leaves are rich in polyphenols and other active ingredients. Polyphenols, due to their antioxidant and metabolic regulating functions, have broad application prospects in the food, health, and pharmaceutical fields. With the increasing demand for natural active ingredients, the large-scale preparation of Eucommia ulmoides leaf polyphenols has become a research focus.

[0003] Most existing methods involve extraction using traditional solvents, but these still have some drawbacks. For example, hot water extraction suffers from inconsistent material-liquid ratios and temperature parameters, insufficient extraction cycles, and a total polyphenol content often below 20g / 100g. Ethanol extraction lacks optimized concentrations, solvent recovery temperatures exceeding 60℃ or unstable vacuum levels lead to polyphenol denaturation, and there are no standards for the dosage / number of chloroform and ethyl acetate, resulting in residues or loss that affect safety and purity. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing polyphenols from Cyclocarya paliurus leaves.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention discloses a method for preparing polyphenols from Cyclocarya paliurus leaves, comprising the following steps: S1 Raw Material Acceptance: In accordance with the raw material acceptance standards for dried leaves of Eucommia ulmoides, the dried leaves of Eucommia ulmoides are subjected to quality testing and screening, and raw materials with mold, insect infestation and excessive impurities are removed. S2 Coarse Grinding: The dried leaves of *Eucommia ulmoides* that have passed QC inspection are put into the grinder for coarse grinding. The particle size of the material after grinding is controlled at 1-5mm. S3 Raw Material Weighing: Weigh the coarsely crushed Cyclocarya paliurus leaves using an electronic scale with an accuracy of 0.1g. S4 Hot Water Extraction: Pure water is used as the extraction solvent, and two water extractions are performed. In the first water extraction, the ratio of Qingqianliu leaves to pure water is 1:10-20 (m:v), and the extraction temperature is controlled at 75-80℃ for 2 hours. In the second water extraction, the ratio of Qingqianliu leaves to pure water is 1:5-10 (m:v), and the extraction temperature is maintained at 75-80℃ for 2 hours. S5 filtration: The extract formed after two hot water extractions is separated from the mixture of plant residue. First, it is coarsely filtered through a 40-mesh stainless steel filter to remove large particles of residue. Then, it is finely filtered through a 25μm polyester filter bag. Centrifugation can be used during the fine filtration process. The centrifugation speed is 3000-5000 r / min and the centrifugation time is 10-15 min to obtain a clear extract. S6 Concentration: Combine the clarified extracts after two water extractions and pass them into a vacuum concentration device. Concentrate under vacuum conditions of 0.08 MPa and a temperature below 60°C until the solid content of the material is 20-30%. After concentration, the material is passed through a 200-mesh nylon screen to remove fine impurities. S7 Spray Drying: The sieved concentrated material is fed into a high-speed centrifugal spray dryer. The inlet air temperature is set to 185℃ and the outlet air temperature is set to 85℃. After drying, powdered material is obtained. The moisture content of the powder is controlled to be below 7%. The dried material is then passed through a 60-mesh sieve. S8 Sieving and Packaging: In a Class 10,000 cleanroom environment, the spray-dried powder is sieved again through a 60-mesh sieve to ensure uniform particle size. Then, it is packaged by an automatic packaging machine, and the packaging material is a food-grade composite film bag. S9 Inspection: Test the total polyphenol content (calculated as gallic acid) in the product, and also test the moisture, ash and microbial indicators to ensure compliance with quality standards; S10 Warehousing: Qualified finished products shall be stored in a dry and cool warehouse with a temperature ≤30℃ and relative humidity of 45%-75%. The warehouse shall be equipped with an automatic temperature and humidity monitoring system. The finished products shall be stored for no more than 36 months. As a preferred embodiment of the present invention, the hot water extraction in step S4 can be replaced by an ethanol extraction process: The coarsely crushed leaves of *Eucommia ulmoides* are ground to a particle size of 0.1-0.5 mm, and 5 times the amount of a 50-70% ethanol solution is added. The mixture is then placed in a constant temperature water bath at 40-50°C for 20 minutes, with stirring every 5 minutes for 30 seconds each time. After extraction, the mixture is filtered using a plate and frame filter press, and the filtrate is collected. The filter residue is then subjected to 2-3 times the amount of a 50-70% ethanol solution for repeated extraction, and the two filtrates are combined. The combined filtrate is then passed into a rotary evaporator and concentrated under reduced pressure at 45°C and a vacuum of 0.07-0.09 MPa. Extract the ethanol solution by stirring until the ethanol is almost completely removed, obtaining a concentrated solution. Add 1 volume of chloroform to the concentrated solution, shake and extract for 10-15 min, allow to stand and separate into layers, remove the lower organic phase, and repeat the extraction twice. Add 2 volumes of ethyl acetate to the remaining aqueous phase, shake and extract for 15-20 min, allow to stand and separate into layers, collect the upper organic phase, and repeat the extraction twice. Pass the collected ethyl acetate phase into a rotary evaporator and concentrate under reduced pressure at 40-45℃ and a vacuum of 0.07-0.09 MPa to recover ethyl acetate and obtain a concentrated product. Place the concentrated product in a vacuum drying oven and dry it at 70℃ and a vacuum of 0.08-0.1 MPa for 4-6 h to obtain an orange-yellow crude polyphenol product. As a preferred embodiment of the present invention, in the ethanol extraction process, after removing ethanol from the concentrate, a purification step is added: hot water at 95°C is added to the concentrate, the amount of hot water being 1-1.5 times the volume of the concentrate; after stirring to dissolve, the solution is filtered, and the filtrate is collected; the filtrate is passed into a rotary evaporator and vacuum concentrated to 1 / 3 of the original volume under conditions of 50-55°C and a vacuum degree of 0.08 MPa; after cooling to room temperature, dichloromethane or trichloromethane is added, the amount of solvent being 0.8-1 times the volume of the concentrate; the solution is extracted by shaking for 10 minutes; after standing and separating into layers, the lower organic phase is removed; the purification process is repeated twice; the purified aqueous phase is mixed with quartz sand at a mass ratio of 1... Mix 2-3, place in a vacuum drying oven, and dry at below 70℃ and a vacuum of 0.08 MPa until a paste is formed; add a 5% (w / w) aqueous acetone solution to the paste, with the amount of acetone added being 5-8 times the mass of the paste, and stir and elute at 30-35℃ for 30 min, then filter and collect the eluent; pass the eluent into a rotary evaporator and concentrate it under vacuum at 40-45℃ and a vacuum of 0.08 MPa to completely recover the acetone; finally, place the remaining aqueous phase containing polyphenols into a freeze dryer and freeze-dry at -40 to -50℃ and a vacuum of 1-10 Pa for 12-16 h to obtain the crude polyphenol product.

[0006] As a preferred embodiment of the present invention, an enzymatic hydrolysis pretreatment step is added before hot water extraction in step S4: Deionized water is added to the coarsely crushed Eucommia ulmoides leaves to adjust the solid-liquid ratio to 1:8-12 (m:v), and then an enzyme preparation is added. The enzyme preparation is one or a combination of cellulase and pectinase, and the enzyme concentration is 0.5-2% of the mass of Eucommia ulmoides leaves. The pH of the system is adjusted to 4-5 with citrate-sodium citrate buffer, and the system is placed in a constant temperature water bath at 40-50℃ for 1-2 hours of enzymatic hydrolysis. During the enzymatic hydrolysis, the system is continuously stirred at a speed of 50-80 r / min. After the enzymatic hydrolysis is completed, the system temperature is raised to 80℃ and kept at this temperature for 10 minutes to inactivate the enzyme before proceeding to the subsequent hot water extraction step.

[0007] As a preferred embodiment of the present invention, the enzyme preparation is a mixture of cellulase and pectinase in a mass ratio of 1:1 to 2:1, with the enzyme activities of the mixed enzymes being 5000 U / g for cellulase and 3000 U / g for pectinase. During the enzymatic hydrolysis process, an online pH monitor is used to monitor the pH value of the system in real time. When the pH value deviates from the range of 4-5, citric acid solution or sodium hydroxide solution is added dropwise for adjustment to ensure the enzymatic hydrolysis efficiency. As a preferred technical solution of the present invention, ultrasonic-assisted extraction is used in step S4 hot water extraction: After mixing Cyclocarya paliurus leaves and pure water according to the material-liquid ratio, the mixture is placed in an ultrasonic extraction device, the ultrasonic frequency is set to 20-40kHz, the ultrasonic power is 200-500W, and ultrasonic-assisted extraction is carried out at 75-80℃ for 10-30 minutes. During the ultrasonic process, an intermittent ultrasonic mode is used, working for 30 seconds and then pausing for 10 seconds, and the process is repeated. After the first ultrasonic extraction is completed, pure water is directly added to the material-liquid ratio for the second water extraction, and the second extraction is carried out according to the above ultrasonic parameters. As a preferred technical solution of the present invention, the ultrasonic probe of the ultrasonic extraction device is inserted into the extraction liquid to a depth of 1 / 3-1 / 2 of the extraction liquid volume, and the distance between the probe and the container wall is ≥5cm to avoid the concentration of ultrasonic energy and the resulting local temperature being too high; during the extraction process, a temperature sensor is used to monitor the system temperature in real time, and when the temperature exceeds 80℃, the cooling system is activated to reduce the temperature to the range of 75-80℃.

[0008] As a preferred technical solution of the present invention, in step S5 filtration, if the turbidity of the extract is high, a microfiltration step is added after coarse filtration with a 40 mesh: microfiltration is performed using a ceramic membrane with a pore size of 0.22 μm, the operating pressure is 0.1-0.15 MPa, the temperature is controlled at 25-35℃, and then fine filtration is performed with a 25 μm filter bag to ensure that the clarity of the extract is ≤5 NTU. As a preferred technical solution of the present invention, a double-effect concentrator is used in the concentration process of step S6. The temperature of the first-effect concentration is controlled at 55-60℃ and the vacuum degree is 0.06-0.07Mpa. The temperature of the second-effect concentration is controlled at 50-55℃ and the vacuum degree is 0.08-0.09Mpa. The double-effect concentration reduces energy consumption and avoids denaturation of polyphenols caused by prolonged high temperature. During the concentration process, samples are taken every 30 minutes to detect the solid content, ensuring that the final solid content is stable at 20-30%. As a preferred technical solution of the present invention, in step S8, during the packaging process, the net content of each bag of product is 250g or 500g. Before packaging, the composite film bag is subjected to ultraviolet sterilization treatment for 15-20 minutes. In step S10, when the product is put into storage, the finished product is stored on pallets with a spacing of ≥10cm and a distance of ≥30cm from the warehouse wall and ≥15cm from the ground. A dehumidifier is installed in the warehouse, which automatically starts dehumidification when the relative humidity exceeds 75% to ensure a stable storage environment.

[0009] The beneficial effects of this invention are: 1. The preparation method of this Cyclocarya paliurus leaf polyphenols optimizes the hot water / ethanol extraction parameters (hot water to liquid ratio 1:10-20 / 1:5-10, ethanol concentration 50-70%), combined with enzymatic hydrolysis (total polyphenols increased to 24.5g / 100g, up 3.3%) or ultrasound assistance (extraction time reduced by 85%, energy consumption reduced by 20%), to improve extraction efficiency; strictly control extraction temperature ≤80℃ and concentration temperature ≤60℃ to avoid polyphenol degradation, and store at 30℃ / 60% humidity for 12 months, the total polyphenol reduction rate is ≤2% (better than conventional ≥5%).

[0010] 2. The preparation method of this Cyclocarya paliurus leaf polyphenols includes enzymatic hydrolysis with a clearly defined compound ratio (cellulase: pectinase = 1:1), concentration of 0.5-2%, pH 4-5, and ultrasonication with a limited frequency of 20-40kHz and power of 200-500W, with standardized parameters. The ultrasonication adopts an intermittent mode to avoid local overheating. Inactivation treatment is performed after enzymatic hydrolysis to solve the problems of low efficiency and polyphenol destruction. Attached Figure Description

[0011] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a process diagram for preparing polyphenols from Cyclocarya paliurus leaves according to the present invention. Detailed Implementation

[0012] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0013] This invention provides a method for preparing polyphenols from Cyclocarya paliurus leaves.

[0014] Example 1

[0015] 1.1 Raw material preparation Select freshly picked and naturally dried leaves of *Eucommia ulmoides*, and test them according to the raw material acceptance standards: mold rate ≤0.1%, insect infestation rate ≤0.2%, impurity content ≤0.5%. Use them after passing the QC test. 1.2 Specific Steps (1) Coarse crushing: Put qualified dried leaves of Eucommia ulmoides into a WFJ-15 micro pulverizer, set the crushing particle size to 2mm, and after crushing, pass them through a 1-5mm sieve to remove excessively large particles; (2) Weighing of raw materials: Weigh 500g of coarsely crushed material using a JA2003 electronic scale (accuracy 0.1g); (3) Hot water extraction: First water extraction: Add 15L of pure water to the extraction tank (material-liquid ratio 1:15, m:v), heat to 78℃, and stir and extract at a constant temperature for 2 hours (stirring speed 50r / min). Second water extraction: After filtration, add 8L of pure water (material-to-liquid ratio 1:8, m:v) to the filter residue and maintain a constant temperature of 78℃ for 2 hours for extraction; (4) Filtering: Coarse filtration: Combine the two extracts and filter them through a 40-mesh stainless steel filter to remove large particles of residue; Fine filtration: The coarse filtrate is passed through a 25μm polyester filter bag, and a TDL-5 centrifuge (4000r / min, 12min) is used to assist in separation to obtain a clear extract; (5) Concentration: Pass the clarified extract into a double-effect concentrator (model SJN-2), with the first effect temperature at 58℃ and the vacuum degree at 0.065Mpa, and the second effect temperature at 52℃ and the vacuum degree at 0.085Mpa, to concentrate to a solid content of 25%, and pass the concentrate through a 200-mesh nylon screen. (6) Spray drying: The concentrate was fed into an LPG-5 high-speed centrifugal spray dryer, with the inlet air temperature set at 185℃, the outlet air temperature at 85℃, and the atomizer speed at 28000r / min. The dried powder was collected, passed through a 60-mesh sieve, and the moisture content of the powder was measured to be 6.2%. (7) Packaging and inspection: The powder was packaged into 250g / bags using an automatic packaging machine (model DCS-50) in a Class 10,000 clean area (the composite film bags were sterilized by ultraviolet light for 18min); the total polyphenol content (calculated as gallic acid) was 23.7g / 100g, and the moisture, ash and microbial indicators all met the standards, according to the method of Announcement No. 2 of 2022. (8) Warehousing: Store qualified products in a constant temperature and humidity warehouse (temperature 25℃, humidity 60%) and monitor the temperature and humidity regularly.

[0016] Example 2

[0017] 2.1 Raw material preparation Same as in Example 1, weigh 500g of coarsely crushed Eucommia ulmoides leaves and further grind them to a particle size of 0.3mm using an XZM-100 ball mill. 2.2 Specific Steps (1) Ethanol extraction: First extraction: Add 5L of 60% ethanol solution (5 times the volume) to the extraction tank, heat to 45℃, stir for 30s every 5min (stirring speed 40r / min), and extract for 20min; Filtration: Filtration was carried out using a plate and frame filter press (model XAYB-50) (pressure 0.2Mpa), and the filtrate was collected; Second extraction: Add 3L of 60% ethanol solution (3 times the amount) to the filter residue, repeat the above extraction and filtration steps, and combine the two filtrates; (2) Concentration and de-alcoholization: The combined filtrate was passed into a RE-52AA rotary evaporator and concentrated at 45°C and a vacuum of 0.08 MPa until the volume of the distillate no longer increased (ethanol residue ≤0.5%), yielding 800 mL of concentrated liquid; (3) Solvent extraction: Chloroform removal: Add 800 mL of chloroform (1 volume) to the concentrate, shake and extract for 12 min (shaking frequency 120 times / min), let stand to separate the layers, remove the lower organic phase, and repeat twice; Ethyl acetate extraction: Add 1600 mL of ethyl acetate (twice the volume) to the aqueous phase, shake and extract for 18 min, allow to stand and separate into layers, collect the upper organic phase, and repeat twice; (4) Drying: The ethyl acetate phase was passed through a rotary evaporator (42℃, 0.08Mpa) and concentrated until no distillate was obtained, yielding 120g of concentrate; the concentrate was placed in a DZF-6050 vacuum drying oven (70℃, 0.09Mpa) and dried for 5h to obtain 108g of orange-yellow crude polyphenol product; (5) Testing: The total polyphenol content was 22.8g / 100g, and the residues of ethanol, chloroform and ethyl acetate all met the GB2760 standard.

[0018] Example 3

[0019] 3.1 Raw material preparation Same as in Example 1, weigh out 500g of coarsely crushed Eucommia ulmoides leaves. 3.2 Specific Steps (1) Enzymatic pretreatment: Slurry preparation: Add 10L of deionized water (solid-liquid ratio 1:10) to the material and stir well; Enzyme addition: Add 12g of compound enzyme (cellulase: pectinase = 1:1, enzyme activities of 5000U / g and 3000U / g respectively), enzyme concentration 1.2%; pH adjustment and enzymatic hydrolysis: Adjust the pH to 4.5 with 0.1 mol / L citrate-sodium citrate buffer, place in a 45℃ constant temperature water bath, and stir at 60 r / min for 1.5 h for enzymatic hydrolysis; Enzyme inactivation: Heat to 80℃, hold for 10 minutes, then cool to 75℃; (2) Hot water extraction: Same as step (3) in Example 1, the first material-to-liquid ratio is 1:12, the second is 1:6, and the extraction is carried out at 75℃ for 2 hours each time; (3) Subsequent filtration, concentration, spray drying, and packaging steps are the same as in Example 1; (4) Test: The total polyphenol content is 24.5g / 100g, which is about 3.3% higher than that of the non-enzymatic hydrolysis process.

[0020] Example 4

[0021] 4.1 Raw material preparation Same as in Example 1, weigh out 500g of coarsely crushed Eucommia ulmoides leaves. 4.2 Specific Steps (1) Ultrasonic-assisted extraction: First extraction: Add 18L of pure water (solid-to-liquid ratio 1:18), put it into a KQ-500VDE ultrasonic extractor, set the frequency to 30kHz and the power to 350W, and perform intermittent ultrasonication at 77℃ (working for 30s, pausing for 10s) for 25 minutes. Second extraction: After filtration, add 9L of pure water (solid-to-liquid ratio 1:9) and sonicate for 20 minutes with the same parameters; (2) The subsequent filtration, concentration, and spray drying steps are the same as in Example 1; (3) Test: The total polyphenol content is 23.9g / 100g, the total extraction time is shortened by 85% compared with traditional hot water extraction, and the energy consumption is reduced by about 20%.

[0022] Example 5

[0023] 5.1 Raw material preparation and preliminary steps Same as in Example 2, complete ethanol extraction, concentration and de-alcoholization (to obtain 800 mL of concentrated solution). 5.2 Refining Steps (1) Hot water dissolution and filtration: Add 960 mL of 95℃ hot water (1.2 times the volume) to the concentrate, stir to dissolve, and then microfilter through a 0.22 μm ceramic membrane (operating pressure 0.12 MPa, 30℃), and collect the filtrate; (2) Preliminary concentration: The filtrate was passed through a rotary evaporator (52℃, 0.08Mpa) and concentrated to 260mL; (3) Removal of impurities: After cooling to room temperature, add 260 mL of dichloromethane, shake and extract for 10 min, let stand to separate the layers and remove the lower organic phase, repeat twice; (4) Sand-mixed drying: Mix the purified aqueous phase with 260g of quartz sand (mass ratio 1:2), place it in a vacuum drying oven (65℃, 0.08Mpa) and dry for 4h to obtain 320g of paste; (5) Acetone elution: Add 1920 mL of 5% aqueous acetone (6 times the mass) to the paste, stir and elute at 32°C for 30 min, filter and collect the eluent; (6) Freeze-drying: The eluent was passed into a rotary evaporator (43℃, 0.08Mpa) and concentrated until no acetone distilled off. The remaining aqueous phase was placed in an LGJ-10 freeze dryer (-45℃, 5Pa) and dried for 14 hours to obtain 92g of refined polyphenol product. (7) Inspection: Total polyphenol content 25.1g / 100g, ash content ≤0.3%, purity increased by about 10% compared with unrefined process.

[0024] Stability tests were conducted on the products of the above five embodiments (stored at 30℃ and 60% humidity for 12 months). The results showed that the total polyphenol content decreased by ≤2%, the moisture content remained between 4.5% and 6.8%, and there were no abnormalities in microbial indicators. These results were superior to existing technology products (the total polyphenol content decreased by ≥5% after 12 months of storage using conventional processes). Furthermore, all embodiments strictly adhered to the precautions of "extraction temperature ≤80℃ and concentration temperature ≤60℃," and no polyphenol denaturation issues were observed, meeting the safety and stability requirements for industrial production.

[0025] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing polyphenols from Cyclocarya paliurus leaves, characterized in that, Includes the following steps: S1 Raw Material Acceptance: In accordance with the raw material acceptance standards for dried leaves of Eucommia ulmoides, the dried leaves of Eucommia ulmoides are subjected to quality testing and screening, and raw materials with mold, insect infestation and excessive impurities are removed. S2 Coarse Grinding: The dried leaves of *Eucommia ulmoides* that have passed QC inspection are put into the grinder for coarse grinding. The particle size of the material after grinding is controlled at 1-5mm. S3 Raw Material Weighing: Weigh the coarsely crushed Cyclocarya paliurus leaves using an electronic scale with an accuracy of 0.1g. S4 Hot Water Extraction: Pure water is used as the extraction solvent, and two water extractions are performed. In the first water extraction, the ratio of Qingqianliu leaves to pure water is 1:10-20 (m:v), and the extraction temperature is controlled at 75-80℃ for 2 hours. In the second water extraction, the ratio of Qingqianliu leaves to pure water is 1:5-10 (m:v), and the extraction temperature is maintained at 75-80℃ for 2 hours. S5 filtration: The extract formed after two hot water extractions is separated from the mixture of plant residue. First, it is coarsely filtered through a 40-mesh stainless steel filter to remove large particles of residue. Then, it is finely filtered through a 25μm polyester filter bag. Centrifugation can be used during the fine filtration process. The centrifugation speed is 3000-5000 r / min and the centrifugation time is 10-15 min to obtain a clear extract. S6 Concentration: Combine the clarified extracts after two water extractions and pass them into a vacuum concentration device. Concentrate under vacuum conditions of 0.08 MPa and a temperature below 60°C until the solid content of the material is 20-30%. After concentration, the material is passed through a 200-mesh nylon screen to remove fine impurities. S7 Spray Drying: The sieved concentrated material is fed into a high-speed centrifugal spray dryer. The inlet air temperature is set to 185℃ and the outlet air temperature is set to 85℃. After drying, powdered material is obtained. The moisture content of the powder is controlled to be below 7%. The dried material is then passed through a 60-mesh sieve. S8 Sieving and Packaging: In a Class 10,000 cleanroom environment, the spray-dried powder is sieved again through a 60-mesh sieve to ensure uniform particle size. Then, it is packaged by an automatic packaging machine, and the packaging material is a food-grade composite film bag. S9 Inspection: Test the total polyphenol content (calculated as gallic acid) in the product, and also test the moisture, ash and microbial indicators to ensure compliance with quality standards; S10 Warehousing: Qualified finished products shall be stored in a dry and cool warehouse with a temperature ≤30℃ and relative humidity of 45%-75%. The warehouse shall be equipped with an automatic temperature and humidity monitoring system. The finished products shall be stored for no more than 36 months.

2. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 1, characterized in that, In step S4, hot water extraction can be replaced with ethanol extraction: Grind the coarsely crushed Eucommia ulmoides leaves to a particle size of 0.1-0.5 mm, add 5 times the amount of 50-70% ethanol solution, and place in a constant temperature water bath at 40-50℃ for 20 minutes. During the extraction process, stir once every 5 minutes for 30 seconds each time. After extraction, filter using a plate and frame filter press, collect the filtrate, and add 2-3 times the amount of 50-70% ethanol solution to the filter residue for repeated extraction once. Combine the two filtrates. Pass the combined filtrate into a rotary evaporator and concentrate under reduced pressure at 45℃ and a vacuum of 0.07-0.09 MPa until the ethanol content is basically reduced. Remove the impurities to obtain a concentrated solution; add 1 volume of chloroform to the concentrated solution, shake and extract for 10-15 min, allow to stand and separate into layers, remove the lower organic phase, and repeat the extraction twice; add 2 volumes of ethyl acetate to the remaining aqueous phase, shake and extract for 15-20 min, allow to stand and separate into layers, collect the upper organic phase, and repeat the extraction twice; pass the collected ethyl acetate phase into a rotary evaporator and concentrate under reduced pressure at 40-45℃ and a vacuum of 0.07-0.09 MPa to recover ethyl acetate and obtain a concentrate; place the concentrate in a vacuum drying oven and dry at 70℃ and a vacuum of 0.08-0.1 MPa for 4-6 h to obtain an orange-yellow crude polyphenol product.

3. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 2, characterized in that, In the ethanol extraction process, after removing ethanol from the concentrate, an impurity removal and purification step is added: Hot water at 95°C is added to the concentrate, the amount of hot water being 1-1.5 times the volume of the concentrate. After stirring to dissolve, the solution is filtered, and the filtrate is collected. The filtrate is then passed through a rotary evaporator and vacuum concentrated to 1 / 3 of its original volume at 50-55°C and a vacuum degree of 0.08 MPa. After cooling to room temperature, dichloromethane or trichloromethane is added, the amount of solvent being 0.8-1 times the volume of the concentrate. The mixture is shaken and extracted for 10 minutes. After standing and separating the layers, the lower organic phase is removed. This impurity removal process is repeated twice. The purified aqueous phase is then mixed with quartz sand at a mass ratio of 1:2-3. Place the sample in a vacuum drying oven and dry it at a temperature below 70°C and a vacuum degree of 0.08 MPa until a paste is formed. Add a 5% (w / w) aqueous acetone solution to the paste, with the amount of acetone added being 5-8 times the mass of the paste. Stir and elute at 30-35°C for 30 min, and filter to collect the eluent. Pass the eluent into a rotary evaporator and concentrate it under vacuum at 40-45°C and a vacuum degree of 0.08 MPa to completely recover the acetone. Finally, place the remaining aqueous phase containing polyphenols into a freeze dryer and freeze-dry it at -40 to -50°C and a vacuum degree of 1-10 Pa for 12-16 h to obtain the crude polyphenol product.

4. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 1, characterized in that, In step S4, before hot water extraction, an enzymatic pretreatment step is added: Deionized water is added to the coarsely crushed Eucommia ulmoides leaves to adjust the solid-liquid ratio to 1:8-12 (m:v), and then an enzyme preparation is added. The enzyme preparation is one or a combination of cellulase and pectinase, and the enzyme concentration is 0.5-2% of the mass of Eucommia ulmoides leaves. The pH of the system is adjusted to 4-5 with citrate-sodium citrate buffer, and the system is placed in a constant temperature water bath at 40-50℃ for 1-2 hours of enzymatic hydrolysis. During the enzymatic hydrolysis, the system is continuously stirred at a speed of 50-80 r / min. After the enzymatic hydrolysis is completed, the system temperature is raised to 80℃ and kept at this temperature for 10 minutes to inactivate the enzyme before proceeding to the subsequent hot water extraction step.

5. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 4, characterized in that, The enzyme preparation is a mixture of cellulase and pectinase in a mass ratio of 1:1 to 2:1, with enzyme activities of 5000 U / g for cellulase and 3000 U / g for pectinase. During the enzymatic hydrolysis process, the pH value of the system is monitored in real time using an online pH monitor. When the pH value deviates from the range of 4-5, citric acid solution or sodium hydroxide solution is added dropwise to adjust it in time to ensure the enzymatic hydrolysis efficiency.

6. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 1, characterized in that, In step S4, ultrasonic-assisted extraction is used during hot water extraction: After mixing Cyclocarya paliurus leaves with pure water according to the material-to-liquid ratio, the mixture is placed in an ultrasonic extraction device. The ultrasonic frequency is set to 20-40kHz and the ultrasonic power to 200-500W. Ultrasonic extraction is performed at 75-80℃ for 10-30 minutes. During the ultrasonic process, an intermittent ultrasonic mode is used, working for 30 seconds and then pausing for 10 seconds, and the process is repeated. After the first ultrasonic extraction is completed, pure water is added directly to the material-to-liquid ratio for the second water extraction, and the second extraction is performed according to the above ultrasonic parameters.

7. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 6, characterized in that, The ultrasonic probe of the ultrasonic extraction equipment is inserted into the extract to a depth of 1 / 3 to 1 / 2 of the extract volume, and the distance between the probe and the container wall is ≥5cm to avoid concentrated ultrasonic energy leading to excessively high local temperatures. During the extraction process, a temperature sensor is used to monitor the system temperature in real time. When the temperature exceeds 80℃, the cooling system is activated to reduce the temperature to the range of 75-80℃.

8. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 1, characterized in that, If the turbidity of the extract is high during the filtration process in step S5, a microfiltration step is added after the 40-mesh coarse filtration: microfiltration is performed using a ceramic membrane with a pore size of 0.22μm, the operating pressure is 0.1-0.15Mpa, the temperature is controlled at 25-35℃, and then fine filtration is performed using a 25μm filter bag to ensure that the clarity of the extract is ≤5NTU.

9. The method for preparing Polyphenols from Cyclocarya paliurus leaves according to claim 1, characterized in that, In step S6, a double-effect concentrator is used for concentration. The temperature of the first concentration effect is controlled at 55-60℃ and the vacuum degree is 0.06-0.07 MPa. The temperature of the second concentration effect is controlled at 50-55℃ and the vacuum degree is 0.08-0.09 MPa. The double-effect concentration reduces energy consumption and avoids denaturation of polyphenols caused by prolonged high temperature. During the concentration process, samples are taken every 30 minutes to test the solid content, ensuring that the final solid content is stable at 20-30%.

10. The method for preparing *Cyclocarya paliurus* leaf polyphenols according to claim 1, characterized in that, During the packaging process in step S8, each bag of product has a net content of 250g or 500g. Before packaging, the composite film bag is subjected to ultraviolet sterilization treatment for 15-20 minutes. In step S10, when the product is put into storage, the finished products are stored on pallets with a spacing of ≥10cm and a distance of ≥30cm from the warehouse wall and ≥15cm from the floor. A dehumidifier is installed in the warehouse, which automatically starts dehumidification when the relative humidity exceeds 75% to ensure a stable storage environment.

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