Method for preparing tea drink from freeze-dried cordyceps militaris

Abstract

The invention discloses a method for preparing a tea drink from freeze-dried cordyceps militaris, and relates to the technical field of tea drink preparation, and the method comprises the following steps: step 1, raw material preparation, step 2, raw material screening, step 3, raw material primary mixing, step 4, auxiliary material particle preparation: porous starch and sodium alginate are mixed according to a ratio of 3: 1, and particles are prepared through spray drying. The surfaces of the particles are coated with pH sensitive chitosan films; and 5, performing final mixing in a low-temperature mixing tank, namely putting the primarily mixed raw materials and the slow-release particles into the low-temperature mixing tank according to the ratio of 20: 1, and performing final mixing on the materials. The cordyceps militaris tea drink has the advantages that the dissolution rate of active ingredients is increased, the uniformity and stability of materials are guaranteed, the brewing taste is improved, and functions are synergistically released, and the problems that in the prior art, the active ingredients of the cordyceps militaris tea drink are insufficiently released, mixing is uneven, and thermosensitive ingredients are prone to inactivation are solved.

Description

Technical Field

[0001] The invention relates to the technical field of tea preparation, in particular to a method for preparing tea from freeze-dried Cordyceps militaris. Background Art

[0002] With the improvement of people's health awareness and the rapid development of the natural food and beverage market, functional tea drinks made from plants with medicinal and edible properties are increasingly favored by consumers. As a traditional Chinese medicinal material, Cordyceps militaris is rich in active ingredients such as cordycepic acid, adenosine, and polysaccharides. It has multiple physiological functions such as enhancing immunity, anti-oxidation, and anti-fatigue. In recent years, it has been widely used in the development of health drinks. However, the fruiting body of Cordyceps militaris has a hard texture and a dense cell wall structure. The active ingredients in it are difficult to fully release under normal temperature brewing conditions, which limits its application in ready-to-drink tea drinks.

[0003] At present, there are several common problems with Cordyceps militaris tea on the market: first, the raw material processing method is single, and there is a lack of optimization of the enzymatic hydrolysis process for cell wall degradation; second, the compatibility of auxiliary materials is unreasonable, and the synergistic release mechanism of flavor substances and functional ingredients is not considered; third, the mixing process is backward, and conventional stirring equipment is difficult to achieve uniform mixing of a variety of powder materials with large density differences, and auxiliary material particles are prone to sedimentation or agglomeration; fourth, the environmental control during the processing process is insufficient, and high temperature and high humidity environments can easily lead to problems such as inactivation of heat-sensitive ingredients and dissolution and failure of auxiliary material coatings, affecting the stability of the finished product and the consistency of taste. Especially in the low-temperature mixing and packaging process, how to ensure the uniformity of the material while maintaining its stable physical and chemical properties is still a technical difficulty that needs to be urgently solved in the industry. Therefore, a method for preparing tea beverages from freeze-dried Cordyceps militaris is needed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing tea beverages by freeze-dried Cordyceps militaris, which has the advantages of improving the dissolution rate of active ingredients, ensuring the uniformity and stability of materials, improving the brewing taste and synergistic release of functions, and solves the problems of insufficient release of effective ingredients in Cordyceps militaris tea beverages, uneven mixing, and easy inactivation of heat-sensitive ingredients in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing tea by freeze-dried Cordyceps militaris, comprising the following steps:

[0006] Step 1: Raw material preparation. The fruiting bodies of Cordyceps militaris are soaked in 75% alcohol for 5 seconds, then rinsed 3 times with sterile water to remove surface impurities. Add 0.3 U / g of cellulase and 0.15 U / g of polyphenol oxidase, and enzymolyze for 2.5 hours at a pH value of 5.5 and a temperature of 40°C. Synchronously add 0.06 g / L of pectinase and 0.2 g / L of ascorbic acid for color protection. Mulberry leaves, kudzu roots, and chrysanthemums are respectively ultrafinely ground to 200 mesh, and licorice is dried at 60°C at low temperature and then ground to 100 mesh for standby.

[0007] Step 2: Raw material screening. The enzymolysis solution of Cordyceps militaris is freeze-dried and then ground, and the caked particles are removed through an 80-mesh vibrating screen. The mulberry leaf powder and kudzu root powder are respectively screened through a 100-mesh sieve by air flow, and the water content is controlled ≤ 5%. The chrysanthemum and licorice powder are passed through a magnetic separator to remove metal impurities.

[0008] Step 3: Initial mixing of raw materials. Put 5 - 10 parts of freeze-dried Cordyceps militaris powder, 8 - 12 parts of mulberry leaf powder, 3 - 5 parts of kudzu root powder, 1 - 3 parts of chrysanthemum powder, and 1 - 2 parts of licorice powder into a three-dimensional motion mixer according to the mass ratio, and mix at a low speed of 20 r / min for 15 minutes.

[0009] Step 4: Preparation of auxiliary particles. Mix porous starch and sodium alginate in a ratio of 3:1, load 1.5 U / g of tannase and 5% of β-cyclodextrin, and make particles with a particle size of 80 - 150 μm through spray drying. The surface of the particles is coated with a pH-sensitive chitosan film with a thickness of 50 - 100 nm, and cross-linked in a 0.5% calcium chloride solution for 10 minutes to form a controlled-release layer.

[0010] Step 5: Final mixing in a low-temperature mixing tank. Put the initially mixed raw materials and the slow-release particles into the low-temperature mixing tank according to a ratio of 20:1 for final material mixing.

[0011] Step 6: Packaging. Use corn fiber tea bags, fill them quantitatively at 3 g per bag, seal them in an aluminum film bag by a nitrogen-filling packaging machine, and simultaneously perform pasteurization at 65°C for 30 minutes.

[0012] Preferably, as a method for preparing a tea drink from freeze-dried Cordyceps militaris of the present invention, the preparation method of the pH-sensitive chitosan film includes: dissolving chitosan in a 1% acetic acid solution, and forming a film in a 0.5% CaCl2 solution through an ion cross-linking method after blending with the slow-release particles.

[0013] Preferably, as a method for preparing a tea drink from freeze-dried Cordyceps militaris of the present invention, the low-temperature mixing tank includes a swing frame, a sealed tank, a longitudinal material mixing mechanism, and a transverse material mixing mechanism;

[0014] The swing frame includes a base, a controller, and a first motor, and the controller and the first motor are fixedly installed on the swing frame;

[0015] The sealed tank includes a tank body and a tank lid, and the tank lid is movably installed on a swing frame;

[0016] The longitudinal mixing mechanism includes a stirring shaft, a guiding cylinder, a second motor, a turntable, a low-temperature carbon dioxide gas cylinder, and a gas supply jacket, and the longitudinal mixing mechanism is installed at the bottom of the sealed tank;

[0017] The transverse mixing mechanism includes a third motor, a mixing disk, and a baffle plate, and the transverse mixing mechanism is installed on the side end face of the sealed tank.

[0018] Preferably, for the method of preparing tea drink from freeze-dried cordyceps militaris of the present invention, first rotating shafts rotatably connected to a base are provided on the left and right sides of the tank body, the first motor drives the first rotating shafts, the tank lid is rotatably connected to the tank body through a hinge, and a buckle for fixation is provided on the tank body.

[0019] Preferably, for the method of preparing tea drink from freeze-dried cordyceps militaris of the present invention, the second motor is fixedly installed at the bottom of the tank body, the stirring shaft is fixedly installed on the output shaft of the second motor, a turntable is provided at the bottom of the stirring shaft, and shoveling plates are evenly arranged on the upper end face of the turntable.

[0020] Preferably, for the method of preparing tea drink from freeze-dried cordyceps militaris of the present invention, a gas supply jacket rotatably connected is provided at the bottom of the side end face of the stirring shaft, a trachea for through connection is provided between the gas supply jacket and the low-temperature carbon dioxide gas cylinder, blowing holes are provided on the side end face of the shoveling plate, an air passage communicating with the blowing holes is provided in the turntable, and an air inlet communicating with the air passage and the gas supply jacket is provided at the bottom of the side end face of the stirring shaft.

[0021] Preferably, for the method of preparing tea drink from freeze-dried cordyceps militaris of the present invention, spiral blades are provided on the side end face of the stirring shaft, the guiding cylinder is sleeved outside the spiral blades, and fixing rods fixedly connected to the tank body are provided on the side end face of the guiding cylinder.

[0022] Preferably, for the method of preparing tea drink from freeze-dried cordyceps militaris of the present invention, the third motor is fixedly installed at the side end of the tank body, the baffle plate is fixedly installed on the inner end face of the tank body, the baffle plate is of an inclined structure, a mixing groove is provided on the upper end face of the baffle plate, the mixing disk is fixedly installed on the output shaft of the third motor, and turning rods fitting with the mixing groove are provided on the side end face of the mixing disk.

[0023] Preferably, for the method of preparing tea drink from freeze-dried cordyceps militaris of the present invention, a discharge port is provided at the end of the baffle plate away from the mixing groove, and a baffle plate rotatably connected to the baffle plate through a hinge is provided at the upper end of the discharge port.

[0024] Preferably, for the method of preparing the freeze-dried cordyceps militaris tea of the present invention, a pressure relief valve is provided on the can lid. The pressure relief valve includes a sleeve, a piston and a spring. The sleeve is fixedly installed on the can lid and is connected to it in a penetrating manner. The piston and the spring are installed inside the sleeve. The piston is elastically slidably connected to the sleeve through the spring. An exhaust hole is provided on the side end face of the sleeve.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. Through the composite motion structure of the longitudinal spiral blade and the transverse material turning rod, combined with the reciprocating swing of the sealed tank body, the present invention vertically lifts the bottom layer of materials through the spiral blade, and the material turning rod cuts and disperses the transverse materials, effectively solving the problems of auxiliary material particle sedimentation and caking caused by material density differences in traditional mixing. At the same time, an integrated low-temperature carbon dioxide gas circulation system is integrated. Inert gas is released through the blowing holes to form a dynamic air flow, which reduces the temperature and humidity in the tank while displacing air, avoiding the inactivation of heat-sensitive components of cordyceps militaris and preventing the pre-dissolution of auxiliary material particles or the moisture absorption and deterioration of raw materials in a high-humidity environment, ensuring the uniformity of the final mixed materials and the integrity of functional components from the dual dimensions of physical mixing and environmental control.

[0027] 2. Through the linkage design of the sealed tank body locked by a buckle and the spring pressure relief valve, the present invention realizes fully enclosed mixing operation while using the piston-type pressure relief structure to dynamically adjust the pressure in the tank, preventing the risk of container bursting caused by gas expansion, and enabling the mixing process to be completed under the protection of inert gas, eliminating the pollution of active substances by the external environment. This design not only simplifies the aseptic operation process but also solves the industry pain points of being easily interfered by the environment, cross-contaminated, and process parameter drift in traditional open mixing through precise regulation of pressure and gas.

[0028] 3. Through the synergistic effect of the centrifugal force field generated by the swing of the tank body and the eddy current field formed by the rotation of the stirring shaft, the present invention simulates the principle of natural convection diffusion, enabling the raw materials and the coated auxiliary material particles to form a progressive combination. While inhibiting the enzyme activity, the low-temperature carbon dioxide gas flow promotes the fluffiness of the powder through gas penetration, improving the dissolution characteristics during the brewing of the tea. This structural design effectively solves the problems of aroma volatilization and damage to the auxiliary material film layer caused by conventional high-temperature mixing, enabling the tea bag to precisely trigger the gradient release of the pH-sensitive film during brewing and achieving the sequential dissolution balance of flavor substances and functional components. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the process flow chart of the present invention;

[0030] Figure 2 is the structural schematic diagram of the low-temperature mixing tank of the present invention;

[0031] Figure 3 is the top view of the low-temperature mixing tank of the present invention;

[0032] Figure 4 For the present invention Figure 3 Cross-sectional view A-A in

[0033] Figure 5 For the present invention Figure 3 Cross-sectional view B-B in

[0034] Figure 6 Schematic diagram of the cooperation state of the longitudinal mixing mechanism and the transverse mixing mechanism of the present invention

[0035] Figure 7 For the present invention Figure 4 Enlarged view at C in

[0036] Figure 8 For the present invention Figure 5 Enlarged view at D in

[0037] Figure 9 For the present invention Figure 5 Enlarged view at E in

[0038] In the figure: 1, swing frame; 101, base; 102, controller; 103, first motor; 2, sealed tank; 201, tank body; 2011, first rotating shaft; 202, tank cover; 203, pressure relief valve; 2031, sleeve; 20311, exhaust hole; 2032, piston; 2033, spring; 204, buckle; 3, longitudinal mixing mechanism; 301, stirring shaft; 3011, spiral blade; 302, guide cylinder; 3021, fixed rod; 304, second motor; 305, turntable; 3051, shoveling plate; 3052, blowing hole; 3053, air duct; 3054, air inlet; 306, low-temperature carbon dioxide gas cylinder; 3061, air pipe; 307, air supply jacket; 4, transverse mixing mechanism; 401, third motor; 402, mixing disc; 4021, turning rod; 403, baffle plate; 4031, mixing tank; 4032, material guiding lip; 4033, discharge port; 404, baffle.

[0039] In the figure: Specific implementation mode

[0040] Example 1

[0041] Please refer to Figures 1-9 , a method for preparing a tea drink from freeze-dried cordyceps militaris, comprising the following steps:

[0042] Step 1, Raw material preparation: Soak the fruiting bodies of Cordyceps militaris in 75% alcohol for 5 seconds, then rinse with sterile water 3 times to remove surface impurities. Add 0.3 U / g of cellulase and 0.15 U / g of polyphenol oxidase, and carry out enzymatic hydrolysis for 2.5 hours at a pH value of 5.5 and a temperature of 40°C. Synchronously add 0.06 g / L of pectinase and 0.2 g / L of ascorbic acid for color protection. Crush mulberry leaves, kudzu roots, and chrysanthemums to 200 meshes by ultrafine grinding respectively, and dry the licorice at 60°C at low temperature and then crush it to 100 meshes for standby;

[0043] Step 2, Raw material screening: Freeze-dry and crush the Cordyceps militaris enzymatic hydrolysate, remove agglomerated particles through an 80-mesh vibrating screen. Screen the mulberry leaf powder and kudzu root powder respectively through a 100-mesh sieve by air flow, control the water content ≤ 5%, and remove metal impurities from the chrysanthemum and licorice powder through a magnetic separator;

[0044] Step 3, Initial mixing of raw materials: Put 5 - 10 parts of freeze-dried Cordyceps militaris powder, 8 - 12 parts of mulberry leaf powder, 3 - 5 parts of kudzu root powder, 1 - 3 parts of chrysanthemum powder, and 1 - 2 parts of licorice powder into a three-dimensional motion mixer according to the mass ratio, and mix at a low speed of 20 r / min for 15 minutes;

[0045] Step 4, Preparation of auxiliary particles: Mix porous starch and sodium alginate in a ratio of 3:1, load 1.5 U / g of tannase and 5% β-cyclodextrin, and make particles with a particle size of 80 - 150 μm by spray drying. Coat the surface of the particles with a pH-sensitive chitosan film with a thickness of 50 - 100 nm, and crosslink in a 0.5% calcium chloride solution for 10 minutes to form a controlled-release layer;

[0046] Step 5, Final mixing in a low-temperature mixing tank: Put the initially mixed raw materials and the slow-release particles into the low-temperature mixing tank according to a ratio of 20:1 for final material mixing;

[0047] Step 6, Packaging: Use corn fiber tea bags, fill them quantitatively at 3 g per bag, seal them in an aluminum film bag by a nitrogen-filling packaging machine, and simultaneously carry out pasteurization at 65°C for 30 minutes.

[0048] Furthermore, the preparation method of the pH-sensitive chitosan film includes: Dissolve chitosan in a 1% acetic acid solution, mix it with the slow-release particles, and form a film in a 0.5% CaCl2 solution by ion crosslinking method.

[0049] The film thickness is regulated by the crosslinking time, usually 10 - 30 minutes, to achieve the release of 30% of tannase in the initial 0 - 3 minutes of brewing, and the continuous release of the remaining 70% within the subsequent 10 minutes.

[0050] Furthermore, in Step 5, the low-temperature mixing tank includes a swing frame 1, a sealed tank 2, a longitudinal mixing mechanism 3, and a transverse mixing mechanism 4;

[0051] The swing frame 1 includes a base 101, a controller 102, and a first motor 103. The controller 102 and the first motor 103 are fixedly installed on the swing frame 1;

[0052] The sealed tank 2 includes a tank body 201 and a tank cover 202. The tank cover 202 is movably installed on the swing frame 1;

[0053] The longitudinal mixing mechanism 3 includes a stirring shaft 301, a guiding cylinder 302, a second motor 304, a turntable 305, a low-temperature carbon dioxide gas cylinder 306, and a gas supply jacket 307. The longitudinal mixing mechanism 3 is installed at the bottom of the sealed tank 2;

[0054] The transverse mixing mechanism 4 includes a third motor 401, a mixing disc 402, and a baffle plate 403. The transverse mixing mechanism 4 is installed on the side end face of the sealed tank 2.

[0055] Further, on the left and right sides of the tank body 201, there are first rotating shafts 2011 rotatably connected to the base 101. The first motor 103 drives the first rotating shafts 2011. The tank cover 202 is rotatably connected to the tank body 201 through a hinge, and on the tank body 201, there is a buckle 204 for fixing.

[0056] The tank body 201 and the tank cover 202 are fixedly sealed through the buckle 204. The sealed tank 2 forms a sealed cavity, isolated from the external environment. The first motor 103 drives the first rotating shafts 2011 to reciprocally rotate, thereby driving the sealed tank 2 to swing back and forth, promoting the mixing of the materials inside the sealed tank 2.

[0057] Further, the second motor 304 is fixedly installed at the bottom of the tank body 201. The stirring shaft 301 is fixedly installed on the output shaft of the second motor 304. At the bottom of the stirring shaft 301, there is a turntable 305, and on the upper end face of the turntable 305, there are uniformly arranged material shoveling plates 3051.

[0058] The second motor 304 drives the stirring shaft 301 to rotate, thereby driving the turntable 305 to rotate. The material shoveling plates on the surface of the turntable 305 drive the mixing of the bottom layer of materials, thereby promoting the mixing of the basic raw materials and the auxiliary particles.

[0059] Further, at the bottom of the side end face of the stirring shaft 301, there is a gas supply jacket 307 rotatably connected. Between the gas supply jacket 307 and the low-temperature carbon dioxide gas cylinder 306, there is a through-connected air pipe 3061. On the side end face of the material shoveling plate 3051, there are blowing holes 3052. Inside the turntable 305, there is an air passage 3053 communicating with the blowing holes 3052. At the bottom of the side end face of the stirring shaft 301, there is an air inlet 3054 communicating with the air passage 3053 and the gas supply jacket 307.

[0060] Supply air to the air supply jacket 307 through the low-temperature carbon dioxide gas cylinder 306. The air supply jacket 307 ensures that air can be stably supplied into the air duct 3053 while the stirring shaft 301 is rotating, allowing carbon dioxide gas to enter the sealed tank 2 and expelling the air in the tank. On the one hand, it reduces the temperature of the material to prevent the inactivation of active substances in Cordyceps militaris. On the other hand, it reduces the humidity in the tank to prevent the material from caking or the auxiliary material particles from dissolving in a high-humidity or high-temperature environment, or the tea from getting damp and losing its flavor. Moreover, the carbon dioxide gas blows the bottom layer of the material, improving the fluffiness of the material, promoting mixing, and preventing material accumulation.

[0061] Further, a spiral blade 3011 is provided on the side end face of the stirring shaft 301, and a guide cylinder 302 is sleeved outside the spiral blade 3011. A fixing rod 3021 fixedly connected to the tank body 201 is provided on the side end face of the guide cylinder 302.

[0062] The second motor 304 drives the stirring shaft 301 to rotate, so that the stirring shaft 301 drives the spiral blade 3011 to rotate, continuously conveying the bottom layer of the material upward, thereby preventing the auxiliary material particles from accumulating at the bottom due to their density being greater than that of the raw material, resulting in uneven mixing and affecting the taste of the later tea bags.

[0063] Further, the third motor 401 is fixedly installed on the side end of the tank body 201, the baffle plate 403 is fixedly installed on the inner end face of the tank body 201, the baffle plate 403 is of an inclined structure, a mixing groove 4031 is provided on the upper end face of the baffle plate 403, the mixing disk 402 is fixedly installed on the output shaft of the third motor 401, and turning rods 4021 fitting with the mixing groove 4031 are provided on the side end face of the mixing disk 402.

[0064] The baffle plate 403 intercepts and guides the material lifted by the spiral blade 3011 into the mixing groove 4031. The third motor 401 drives the mixing disk 402 to rotate, and the turning rods 4021 on the side end face of the mixing disk 402 turn the material, promoting further mixing of the raw material and the auxiliary material particles. A guiding lip 4032 is provided at the bottom of the mixing groove 4031 to facilitate discharging.

[0065] Further, a discharge port 4033 is provided at the end of the baffle plate 403 away from the mixing groove 4031, and a baffle 404 rotatably connected to the baffle plate 403 through a hinge is provided at the upper end of the discharge port 4033.

[0066] When the mixing is completed, the first motor 103 drives the cylinder body to turn forward by 120 degrees, so that the baffle 404 no longer blocks the discharge port 4033 under the action of gravity, and the material in the cylinder body can be discharged smoothly.

[0067] Furthermore, a pressure relief valve 203 is provided on the tank cover 202, and the pressure relief valve 203 includes a sleeve 2031, a piston 2032 and a spring 2033. The sleeve 2031 is fixedly installed on the tank cover 202 and is through-connected thereto. The piston 2032 and the spring 2033 are installed in the sleeve 2031. The piston 2032 is elastically slidably connected to the sleeve 2031 through the spring 2033. The side end face of the sleeve 2031 is provided with an exhaust hole 20311.

[0068] The pressure in the tank cover 202 is controlled by the pressure relief valve 203 to avoid excessive pressure in the tank body 201 that may cause the seal to burst. At the same time, the carbon dioxide gas is helped to carry away moist air to prevent external air from entering the sealed tank 2.

[0069] When the low-temperature mixing tank is in use, the tank body 201 and the tank cover 202 are first fixed and sealed by the buckle 204 to form a sealed cavity isolated from the external environment, the first motor 103 is turned on to drive the first rotating shaft 2011 to rotate back and forth to make the sealed tank 2 swing back and forth to preliminarily promote the mixing of materials, and at the same time, the low-temperature carbon dioxide gas cylinder 306 is turned on to supply gas to the air supply jacket 307 through the air pipe 3061. The air supply jacket 307 stably supplies gas to the air channel 3053 when the stirring shaft 301 is rotating. The carbon dioxide gas is discharged from the blowing hole 3052 through the air inlet 3054 and the air channel 3053. On the one hand, the material temperature is reduced to avoid the inactivation of the active substances in Cordyceps militaris, and the humidity in the tank is reduced to avoid the agglomeration of the material or the dissolution of the auxiliary material particles and the change of the taste of the tea due to moisture. On the other hand, the bottom material is blown to improve the fluffiness and promote mixing. Then the second motor 304 drives the stirring shaft 301 to rotate, and the spiral blades on the stirring shaft 301 3011 transports the bottom material upward to prevent the auxiliary material particles from piling up at the bottom due to their high density. The shovel plate 3051 on the surface of the turntable 305 drives the bottom material to mix. At the same time, the third motor 401 drives the stirring disk 402 to rotate. The turning rod 4021 on the side end surface of the stirring disk 402 cooperates with the mixing trough 4031 on the blocking plate 403 to turn the material. The blocking plate 403 intercepts and guides the material lifted by the spiral blade 3011 into the mixing trough 4031 to promote further mixing of the raw material and the auxiliary material particles. During the mixing process, the pressure relief valve 203 controls the pressure in the tank through the piston 2032 and the spring 2033 to avoid excessive pressure causing the seal to burst and help the carbon dioxide gas to take away the humid air. After the mixing is completed, the first motor 103 drives the cylinder to flip forward 120 degrees. The baffle 404 no longer blocks the discharge port 4033 under the action of gravity, and the material in the cylinder is discharged smoothly from the discharge port 4033.

[0070] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a tea drink from freeze-dried Cordyceps militaris, characterized in that: It includes the following steps: Step 1: Raw material preparation. Soak the fruiting bodies of Cordyceps militaris in 75% alcohol for 5 seconds, then rinse them 3 times with sterile water to remove surface impurities. Add 0.3 U / g of cellulase and 0.15 U / g of polyphenol oxidase, and carry out enzymatic hydrolysis for 2.5 hours under the conditions of pH value of 5.5 and temperature of 40°C. Synchronously add 0.06 g / L of pectinase and 0.2 g / L of ascorbic acid for color protection. Mulberry leaves, kudzu roots, and chrysanthemums are respectively ultrafinely pulverized to 200 meshes, and licorice is dried at a low temperature of 60°C and then pulverized to 100 meshes for standby; Step 2: Raw material screening. The Cordyceps militaris enzymatic hydrolysis solution is freeze-dried and then pulverized, and the agglomerated particles are removed through an 80-mesh vibrating screen. The mulberry leaf powder and kudzu root powder are respectively screened through an air flow passing through a 100-mesh sieve, and the water content is controlled ≤5%. The chrysanthemum and licorice powder are passed through a magnetic separator to remove metal impurities; Step 3: Primary mixing of raw materials. Put 5-10 parts of freeze-dried Cordyceps militaris powder, 8-12 parts of mulberry leaf powder, 3-5 parts of kudzu root powder, 1-3 parts of chrysanthemum powder, and 1-2 parts of licorice powder into a three-dimensional motion mixer according to the mass ratio, and mix at a low speed of 20 r / min for 15 minutes; Step 4: Preparation of auxiliary particles. Mix porous starch and sodium alginate in a ratio of 3:1, load 1.5 U / g of tannase and 5% of β-cyclodextrin, and make particles with a particle size of 80-150 μm through spray drying. The surface of the particles is coated with a pH-sensitive chitosan film with a thickness of 50-100 nm, and cross-linked in a 0.5% calcium chloride solution for 10 minutes to form a controlled release layer; Step 5: Final mixing in a low-temperature mixing tank. Put the preliminarily mixed raw materials and the sustained-release particles into the low-temperature mixing tank according to a ratio of 20:1 for final material mixing; Step 6: Packaging. Use corn fiber tea bags, quantitatively fill 3 g per bag, and seal them in an aluminum film bag by a nitrogen filling packaging machine, and simultaneously carry out pasteurization at 65°C for 30 minutes.

2. The method for preparing a tea drink from freeze-dried Cordyceps militaris as claimed in claim 1, wherein: The preparation method of the pH-sensitive chitosan film includes: dissolving chitosan in a 1% acetic acid solution, mixing it with the sustained-release particles, and forming a film in a 0.5% CaCl2 solution through an ion cross-linking method.

3. The method for preparing a tea drink from freeze-dried Cordyceps militaris as claimed in claim 1, wherein: In step 5, the low-temperature mixing tank includes a swing frame (1), a sealed tank (2), a longitudinal mixing mechanism (3), and a transverse mixing mechanism (4); The swing frame (1) includes a base (101), a controller (102), and a first motor (103), and the controller (102) and the first motor (103) are fixedly installed on the swing frame (1); The sealed tank (2) includes a tank body (201) and a tank cover (202), and the tank cover (202) is movably installed on the swing frame (1); The longitudinal mixing mechanism (3) includes a stirring shaft (301), a guide cylinder (302), a second motor (304), a turntable (305), a low-temperature carbon dioxide gas cylinder (306), and a gas supply jacket (307), and the longitudinal mixing mechanism (3) is installed at the bottom of the sealed tank (2); The transverse mixing mechanism (4) includes a third motor (401), a stirring disk (402), and a baffle (403), and the transverse mixing mechanism (4) is installed on the side end face of the sealed tank (2).

4. The method for preparing the cordyceps militaris freeze-dried tea according to claim 3, characterized in that: On the left and right sides of the tank body (201), there are first rotating shafts (2011) rotatably connected to the base (101). The first motor (103) drives the first rotating shaft (2011). The tank cover (202) is rotatably connected to the tank body (201) through a hinge. A buckle (204) for fixing is provided on the tank body (201).

5. The method for preparing a tea beverage from freeze-dried Cordyceps militaris as claimed in claim 3, wherein: The second motor (304) is fixedly installed at the bottom of the tank body (201). The stirring shaft (301) is fixedly installed on the output shaft of the second motor (304). At the bottom of the stirring shaft (301), there is a turntable (305). On the upper end face of the turntable (305), there are evenly arranged material shoveling plates (3051).

6. The method for preparing a tea drink from freeze-dried Cordyceps militaris as claimed in claim 5, characterized in that: At the bottom of the side end face of the stirring shaft (301), there is a rotatably connected gas supply jacket (307). Between the gas supply jacket (307) and the low-temperature carbon dioxide gas cylinder (306), there is a through-connected gas pipe (3061). On the side end face of the material shoveling plate (3051), there are blowing holes (3052). Inside the turntable (305), there is an air duct (3053) through-connected to the blowing holes (3052). At the bottom of the side end face of the stirring shaft (301), there is an air inlet (3054) through-connected to the air duct (3053) and the gas supply jacket (307).

7. The method for preparing a tea beverage from freeze-dried Cordyceps militaris as claimed in claim 3, wherein: On the side end face of the stirring shaft (301), there are spiral blades (3011). The guiding cylinder (302) is sleeved outside the spiral blades (3011). On the side end face of the guiding cylinder (302), there are fixing rods (3021) fixedly connected to the tank body (201).

8. The method for preparing a tea drink from freeze-dried Cordyceps militaris as claimed in claim 3, wherein: The third motor (401) is fixedly installed at the side end of the tank body (201). The baffle plate (403) is fixedly installed on the inner end face of the tank body (201). The baffle plate (403) is of an inclined structure. On the upper end face of the baffle plate (403), there is a mixing groove (4031). The stirring disc (402) is fixedly installed on the output shaft of the third motor (401). On the side end face of the stirring disc (402), there are turning rods (4021) fitting with the mixing groove (4031).

9. The method for preparing the cordyceps militaris lyophilized tea according to claim 8, wherein: At the end of the baffle plate (403) away from the mixing groove (4031), there is a discharge port (4033). At the upper end of the discharge port (4033), there is a baffle (404) rotatably connected to the baffle plate (403) through a hinge.

10. The method for preparing a tea drink from freeze-dried Cordyceps militaris as claimed in claim 3, wherein: A pressure relief valve (203) is provided on the tank cover (202). The pressure relief valve (203) includes a sleeve (2031), a piston (2032), and a spring (2033). The sleeve (2031) is fixedly installed on the tank cover (202) and is through-connected thereto. The piston (2032) and the spring (2033) are installed inside the sleeve (2031). The piston (2032) is elastically slidably connected to the sleeve (2031) through the spring (2033). On the side end face of the sleeve (2031), there is an exhaust hole (20311).

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