Preparation method of Pu'er tea containing panax notoginseng leaf and stem extract

Abstract

The invention relates to the field of Pu'er tea preparation, in particular to a preparation method of Pu'er tea with panax notoginseng leaf and stem extracts. The preparation method of the Pu'er tea containing the panax notoginseng leaf and stem extract has the following advantages: (1) steam explosion treatment is combined with an enzymolysis process, and the specific proportion of xylanase and pectinase remarkably improves the breaking efficiency of cell walls of panax notoginseng leaves and stems, so that the yield of the extract and the retention rate of active ingredients are improved; (2) the optimized mass ratio of the fermented Pu'er tea to the pseudo-ginseng extract dry powder to the beta-cyclodextrine to the maltodextrin effectively enhances the flavor coordination and stability of the product, and meanwhile, the embedding effect of the beta-cyclodextrine is utilized to protect notoginsenoside from oxidative degradation and prolong the shelf life; and (3) in the compressed tea process, due to the mass ratio of the particulate matters to the crushed Pu'er ripe tea and the condition of drying for more than 5 hours in a drying box at 40 DEG C, moderate compactness and uniform moisture of the tea cake are ensured, mildewing is avoided, and the biological activity of the extract is kept.

Description

Technical Field

[0001] This invention relates to the field of Pu-erh tea preparation, specifically to a method for preparing Pu-erh tea from Panax notoginseng leaf and stem extract. Background Technology

[0002] Pu-erh tea, a fermented tea with a long history, is widely loved by consumers for its unique aged aroma and health benefits. However, traditional Pu-erh tea production mainly relies on the fermentation of the tea leaves themselves, resulting in relatively simple functional components and a lack of fortification measures targeting specific health needs.

[0003] While existing technologies for Pu-erh tea possess basic functions such as lowering lipids and providing antioxidants, they fall short in increasing the content of saponin-based active substances, resulting in limited health benefits. Furthermore, conventional processes struggle to effectively integrate exogenous plant extracts, easily leading to taste imbalances or nutrient loss. Panax notoginseng, a precious traditional Chinese medicine, is rich in saponins, flavonoids, and other bioactive components, exhibiting significant effects such as promoting blood circulation, removing blood stasis, and enhancing immunity. However, the Pu-erh tea industry has not fully utilized Panax notoginseng resources, particularly lacking mature solutions for the effective extraction and stable integration of Panax notoginseng leaves and stems. Therefore, there is an urgent need to develop a novel Pu-erh tea that extracts the essence of Panax notoginseng leaves and stems and optimizes the preparation process to overcome existing deficiencies. Summary of the Invention

[0004] This invention aims to provide a method for preparing Pu-erh tea from Panax notoginseng leaf and stem extract, the specific scheme of which is as follows: A method for preparing Pu-erh tea from Panax notoginseng leaf and stem extract includes the following steps: (1) Extraction of Panax notoginseng leaves: leaf extract was obtained; (2) Extraction from Panax notoginseng stems: •S1. Steam Explosion Treatment Panax notoginseng stem segments were placed in a steam explosion vessel, 1.2 MPa of saturated steam was introduced, the pressure was maintained for 30 seconds and then the pressure was released instantly to collect the exploded stem segments. •S2. Complex enzymatic hydrolysis and extraction After blasting, the stem segments are crushed to obtain dry powder. The dry powder is added to an extraction tank, ethanol solution is added, and the pH is adjusted to 4-5 to obtain a modified solution. Xylanase and pectinase are added, and the mixture is stirred in a 45°C water bath for 3 hours. The supernatant is collected by centrifugation, and the residue is washed with ethanol solution. The filtrates are combined. •S3. Concentration and Merging The stem extract was concentrated to a relative density of 1.15 and combined with the initial leaf extract to obtain a mixed extract. (3) Purification process: Obtain the total extract of Panax notoginseng in dry powder; (4) Compressed tea processing: •S1. Material Pretreatment The Pu-erh ripe tea is pulverized to 80-100 mesh, mixed with Panax notoginseng total extract dry powder, β-cyclodextrin and maltodextrin, and then passed through a 60-mesh sieve to obtain a mixed powder; •S2. Granulation process Ethanol is added to the mixed powder so that the finished product can be formed into a ball by hand and dispersed with a light touch. Then, it is granulated using a swing granulator. The wet granules are dried with hot air, and the moisture content is controlled at 8-10%. They are then granulated through a 12-mesh sieve to obtain granules. •S3. Molding process When it is made into tea bags, the granules are mixed with 3-5mm Pu-erh tea fragments in a certain proportion and packaged using an automatic bagging machine; when it is made into compressed tea cakes, the granules are put into a mold, pressed by a hydraulic press, and then dried in a drying oven.

[0005] In step S2 of step (2), the solid-liquid ratio of dry powder to ethanol is 1:15.

[0006] In step S2 of step (2), xylanase accounts for 1% of the mass of the preparation solution and pectinase accounts for 0.5% of the mass of the preparation solution.

[0007] In step S1 of step (4), the mass ratio of Pu-erh ripe tea, Panax notoginseng extract powder, β-cyclodextrin and maltodextrin is 80:10:3:2.

[0008] In step S3 of step (4), the mass ratio of particulate matter to broken Pu-erh tea is 3:7.

[0009] In step S3 of step (4), the product is dried in a 40°C drying oven for more than 5 hours.

[0010] Step (3) includes the following steps: resin column pretreatment, sample loading and elution and drying into powder, wherein the resin column is D101 macroporous resin.

[0011] The Panax notoginseng leaves mentioned are dried three-year-old Panax notoginseng leaves with a moisture content of ≤8% and a total saponin content of ≥2.5%.

[0012] The Panax notoginseng stems mentioned are two-year-old stem segments with a diameter equal to that of a two-year-old stem segment.

[0013] The method for preparing Pu-erh tea from Panax notoginseng leaf and stem extract of this invention has the following advantages: (1) By combining steam explosion treatment with enzymatic hydrolysis, the specific ratio of xylanase and pectinase (1% and 0.5% of the mass of the prepared solution, respectively) significantly improved the cell wall breaking efficiency of Panax notoginseng leaf stem, thereby increasing the yield of extract and the retention rate of active ingredients (such as total saponins). (2) The optimized mass ratio of Pu'er ripe tea, Panax notoginseng extract powder, β-cyclodextrin and maltodextrin (80:10:3:2) effectively enhanced the flavor coordination and stability of the product. At the same time, the encapsulation effect of β-cyclodextrin protected Panax notoginseng saponins from oxidative degradation and extended the shelf life. (3) In the compressed tea process, the mass ratio of particulate matter to broken Pu'er tea (3:7) and the drying conditions of drying in a 40℃ drying oven for more than 5 hours ensure that the tea cake has moderate compactness, uniform moisture, avoids mold, and maintains the biological activity of the extract. Detailed Implementation

[0014] I. Raw Materials Panax notoginseng leaves: Dried three-year-old Panax notoginseng leaves, pulverized to 60 mesh (particle size ≤250μm), moisture ≤8%, total saponins ≥2.5%. Panax notoginseng stems: Two-year-old stem segments (diameter 0.4-0.6cm). Pu-erh tea: Sun-dried green tea of ​​Yunnan large-leaf variety. Reagents: Food-grade ethanol (95%), cellulase (enzyme activity ≥5000U / g), D101 macroporous resin (pretreated for later use).

[0015] Preparation method 1. Extract from Panax notoginseng leaves • S1. Enzymatic pretreatment Weigh 1 kg of Panax notoginseng leaf powder and add it to an enzymatic hydrolysis tank. Add 70% ethanol (adjusted to pH 5.0 with citric acid beforehand) at a solid-liquid ratio of 1:20 and stir well. Add 5 g of cellulase (0.5% dosage), start stirring (80 r / min), and incubate in a 50℃ water bath for 2 hours.

[0016] S2. Ultrasonic-assisted extraction Transfer the enzymatic hydrolysate to an ultrasonic extractor, set the temperature to 60℃, power to 300W, and ultrasonic time to 40 minutes (intermittent mode: 5 seconds on, 5 seconds off to avoid local overheating). After extraction, filter while still hot through three layers of gauze. Wash the residue twice with 70% ethanol at room temperature, and combine the filtrates.

[0017] •S3. Reduced pressure concentration The filtrate was transferred to a rotary evaporator (vacuum degree -0.08MPa, water bath temperature 60℃) and concentrated to a relative density of 1.20±0.02 to obtain the initial leaf extract.

[0018] 2. Extraction from Panax notoginseng stems •S1. Steam Explosion Treatment Take 5 kg of Panax notoginseng stem segments, put them into a steam explosion vessel, introduce 1.2 MPa saturated steam, maintain the pressure for 30 seconds and then release the pressure instantly, and collect the exploded stem segments.

[0019] •S2. Complex enzymatic hydrolysis and extraction The crushed stem segments were pulverized to 40 mesh. 1 kg of the dry powder was weighed and added to an extraction tank. 50% ethanol was added at a solid-liquid ratio of 1:15, and the pH was adjusted to 4.5. 10 g (1%) xylanase and 5 g (0.5%) pectinase were added, and the mixture was stirred in a 45°C water bath for 3 hours. The mixture was centrifuged (4000 rpm, 15 minutes) and the supernatant was collected. The residue was washed with 50% ethanol, and the filtrates were combined.

[0020] •S3. Concentration and Merging The stem extract was concentrated to a relative density of 1.15 and combined with the initial leaf extract to obtain a mixed extract.

[0021] 3. Purification process (6 hours / batch) •S1. Resin column pretreatment D101 macroporous resin was soaked in 95% ethanol for 24 hours, and after being packed into the column, it was rinsed with 5 BV of ethanol and then 5 BV of deionized water until there was no alcohol odor. It was then ready for use.

[0022] •S2. Sample loading and elution The mixed extract was diluted with deionized water to a solids content of 10%, and loaded at a flow rate of 2 BV / h (the loading amount ≤ 80% of the total adsorption capacity of the resin column). After loading, the column was washed with 3 BV of deionized water at a flow rate of 3 BV / h (to remove water-soluble impurities), and then eluted with 5 BV of 70% ethanol at a flow rate of 2 BV / h. The eluent was collected (the first 0.5 BV of initial eluent was discarded).

[0023] S3. Dry into powder The eluent was concentrated under reduced pressure until no alcohol odor remained, and then freeze-dried under vacuum (pre-frozen at -40℃ for 3 hours, vacuum degree ≤10Pa, desorption temperature 40℃, drying for 12 hours) to obtain a dry powder of Panax notoginseng total extract (saponins ≥12%, polysaccharides ≥6%).

[0024] Molding process •S1. Material Pretreatment Pulverized Pu-erh tea to 80-100 mesh (800g), 100g of Panax notoginseng total extract dry powder, 30g of β-cyclodextrin, 20g of maltodextrin, mix and pass through a 60-mesh sieve twice (to ensure uniformity RSD≤5%).

[0025] •S2. Granulation process Add 150 mL of 95% ethanol (wetting agent) to the mixed powder to form a soft mass (which can be formed into a ball by hand but crumbles easily when touched), and granulate it using a 16-mesh vibrating granulator. Dry the wet granules with hot air at 60℃ for 2 hours (turning them over once every 30 minutes), controlling the moisture content to 8-10%, and then granulate them through a 12-mesh sieve.

[0026] •S3. Molding process Tea bags: Mix granules with 3-5mm Pu-erh ripe tea fragments at a ratio of 3:7, and package using an automatic bagging machine (5g per bag, heat-sealing temperature 180℃, time 3 seconds).

[0027] Compressed tea cakes: Particles are placed into a 10cm diameter mold, pressed with a hydraulic press at 8MPa for 30 seconds, and dried in a 40℃ drying oven for 12 hours (to prevent mold growth).

[0028] The above 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 a Pu'er tea of Panax notoginseng leaf stem extract, characterized in that, The method comprises the following steps: (1) Panax notoginseng leaf extraction: obtaining leaf extract; (2) Panax notoginseng stem extraction: • S1. Steam explosion treatment Panax notoginseng stem segments are loaded into a steam explosion tank, saturated steam is introduced, pressure is maintained and then instantaneously released, and the exploded stem segments are collected; • S2. Composite enzymatic hydrolysis and extraction The exploded stem segments are crushed to obtain dry powder, the dry powder is added to an extraction tank, ethanol solution is added, the pH is adjusted to 4-5 to obtain a conditioning solution, xylanase and pectinase are added, and water bath stirring is performed; the supernatant is obtained by centrifugation, the residue is washed with ethanol solution, and the filtrates are combined; • S3. Concentration and combination The stem extract is concentrated to a relative density of 1.15, combined with the leaf extract, and a mixed extract is obtained; (3) Purification process: obtaining Panax notoginseng total extract dry powder; (4) Compression tea process: • S1. Material pretreatment Puer tea is crushed to 80-100 mesh, mixed with Panax notoginseng total extract dry powder, beta-cyclodextrin and malt dextrin, sieved to obtain a mixture; • S2. Granulation process The mixture is added with ethanol, so that the finished product can be held together by hand and scattered by a light touch, and then a swing granulator is used for granulation; the wet granules are dried by hot air, the moisture content is controlled at 8-10%, sieved and granulated to obtain granules; • S3. Shaping process When it is a bagged tea, the granules are mixed with 3-5 mm Puer tea fragments in a certain proportion, and packaged by an automatic bagging machine; when it is a compression tea cake, the granules are loaded into a mold, pressed by a hydraulic machine, and then dried in a drying oven.

2. The method of claim 1, wherein the Panax notoginseng stem extract Pu'er tea is prepared by the steps of: a. mixing 1 part of the Panax notoginseng stem extract with 2 parts of Pu'er tea, b. drying the mixture, and c. crushing the dried mixture into a powder. In the S2 step of step (2), the solid-liquid ratio of dry powder to ethanol is 1:

15.

3. The method of claim 1, wherein the Panax notoginseng stem extract Pu'er tea is prepared by the steps of: a. mixing 1 part of the Panax notoginseng stem extract with 2 parts of Pu'er tea, b. drying the mixture, and c. crushing the dried mixture into a powder. In the S2 step of step (2), the xylanase accounts for 1% of the mass of the conditioning solution, and the pectinase accounts for 0.5% of the mass of the conditioning solution.

4. The method of claim 1, wherein the Panax notoginseng stem extract Pu'er tea is prepared by the steps of: a. mixing 1 part of the Panax notoginseng stem extract with 2 parts of Pu'er tea, b. drying the mixture, and c. crushing the dried mixture into a powder. In the S1 step of step (4), the mass ratio of Puer tea, Panax notoginseng extract dry powder, beta-cyclodextrin and malt dextrin is 80:10:3:

2.

5. The method of claim 1, wherein the Panax notoginseng stem extract Pu'er tea is prepared by the steps of: a. mixing 1 part of the Panax notoginseng stem extract with 2 parts of Pu'er tea, b. drying the mixture, and c. pulverizing the dried mixture. In the S3 step of step (4), the mass ratio of granules to Puer tea fragments is 3:

7.

6. The method for preparing Pu-erh tea from Panax notoginseng leaf and stem extract as described in claim 1, characterized in that, In the S3 step of step (4), the granules are dried in a 40°C drying oven for more than 5 hours.

7. The method for preparing Pu-erh tea from Panax notoginseng leaf and stem extract as described in claim 1, characterized in that, The step (3) comprises the following steps: resin column pretreatment, sample loading and elution, and drying to powder, and the resin column is D101 macroporous resin.

8. The method of claim 1, wherein the preparation of the Panax notoginseng stem extract Pu'er tea is characterized by: The Panax notoginseng leaf is dried for three years, with a moisture content of ≤8% and a total saponin content of ≥2.5%.

9. The method of claim 1, wherein the preparation of the Panax notoginseng stem extract Pu'er tea is characterized by: The Panax notoginseng stem is a two-year-old stem segment, with a diameter of two-year-old stem segments.