Silkworm excrement six-fort tea product and its making method

Abstract

The application discloses a kind of silkworm sand six fort tea product's production method, belong to tea processing technical field, method includes: silkworm sand is dried after inoculation Lactobacillus plantarum and carries out initial fermentation, the silkworm sand of initial fermentation is rinsed with clean water, and rinsing silkworm sand, mulberry leaf and tea are mixed according to mass ratio 2:2:6, mixed material is connected into Aspergillus niger spore suspension and Eurotium cristatum spore suspension in turn and carries out two-stage secondary fermentation, finally, fermentation material is low-temperature ventilation drying and aging, and the silkworm sand six fort tea product of obtaining is obtained.The application also provides silkworm sand six fort tea product.The application solves the problems that harmful microorganism remains higher in existing silkworm sand tea, silkworm sand smell is difficult to remove and tea pigment conversion efficiency is low, preliminary degrades peculiar smell substance through Lactobacillus plantarum initial fermentation, degrades silkworm sand crude fiber and protein and promotes tea pigment generation through the fermentation of Aspergillus niger and Eurotium cristatum in turn, and the silkworm sand six fort tea product prepared has high safety, less peculiar smell, high tea pigment content and good flavor quality.

Description

Technical Field

[0001] This invention relates to the field of tea processing technology, and in particular to a silkworm excrement Liubao tea product and its production method. Background Technology

[0002] Silkworm excrement, the waste product of silkworms, has traditionally been used as a medicinal herb or farm fertilizer. In recent years, it has also been explored for use in making health-promoting teas. Silkworm excrement tea is primarily targeted at individuals with health needs such as dispelling dampness, regulating the digestive system, and relieving hangovers and protecting the liver, especially in humid climates where consumers hope to improve their health through daily consumption. Given the high medicinal value and functional components of silkworm excrement, combining it with tea leaves to create tea products is a feasible way to extend the sericulture industry chain and increase the income of silkworm farmers.

[0003] However, existing processing methods for silkworm excrement tea generally involve low-temperature drying, roasting, and simple blending. These methods offer only a superficial treatment of the raw materials. As animal excrement, silkworm excrement often contains significantly higher levels of microorganisms such as E. coli and mold in its initial state, and simple roasting alone is insufficient to reduce these harmful microorganisms to safe levels. Furthermore, the roasting temperature and time are limited by the properties of the raw materials, failing to fully decompose the odor-causing components such as skatole and indole in the silkworm excrement. This results in a noticeable fishy smell in the finished product, making the taste unacceptable to consumers. In addition, simple roasting and blending lack a deep biotransformation process, hindering the effective oxidation and polymerization of polyphenols in the tea leaves and silkworm excrement to form tea pigments, thus failing to fully realize the product's potential health benefits.

[0004] In terms of flavor, existing silkworm excrement teas are mostly formulated according to the principles of traditional Chinese medicine, prioritizing efficacy over taste and texture. These products often have a distinct medicinal flavor and the animalistic odor of silkworm excrement itself, failing to achieve the proper drinking experience of tea. Regarding safety, simple roasting has limited ability to degrade mycotoxins and some pesticide residues. Consumers drinking silkworm excrement tea for health purposes may still ingest a certain amount of harmful substances. As for functional components, tea pigments, as important active substances in tea fermentation products, are typically found in higher concentrations in long-aged dark tea. However, traditional silkworm excrement tea has a short processing cycle, lacking microbial fermentation and aging processes, resulting in a low conversion rate of tea pigments.

[0005] Therefore, it is necessary to improve the existing silkworm excrement tea processing technology to enhance flavor while ensuring safety, and simultaneously improve the conversion rate of functional components such as tea pigments. This improvement should avoid relying on high-temperature roasting and simple blending, and instead introduce a reasonable microbial fermentation process to allow silkworm excrement, mulberry leaves, and tea leaves to undergo deep transformation under the action of microorganisms, thereby solving the problems existing in the current technology. Summary of the Invention

[0006] This invention solves the problems of high levels of harmful microorganisms, difficulty in removing the fishy smell of silkworm excrement, and low conversion efficiency of tea pigments in existing silkworm excrement tea. It initially degrades off-odor substances through the initial fermentation of Lactobacillus plantarum, and degrades the crude fiber and protein of silkworm excrement and promotes the production of tea pigments through the sequential fermentation of Aspergillus niger and Aspergillus cristatus. The resulting silkworm excrement Liubao tea product has high safety, less off-odor, high tea pigment content, and good flavor and quality.

[0007] To achieve the above objectives, the present invention adopts the following solution: A method for producing a type of Liubao tea product containing silkworm excrement includes the following steps: S1: Dry the silkworm excrement in the shade, inoculate the dried silkworm excrement with Lactobacillus plantarum, and carry out primary fermentation under ventilated conditions to obtain primary fermented silkworm excrement; S2: Add the initially fermented silkworm excrement to clean water, stir and let stand, drain the supernatant to obtain rinsed silkworm excrement; S3: Mix the rinsed silkworm excrement, mulberry leaves and tea leaves in a mass ratio of 2:2:6 to obtain a mixture; S4: The mixture is subjected to secondary fermentation, which includes a first stage and a second stage. In the first stage, a suspension of Aspergillus niger spores is introduced into the mixture, and it is allowed to ferment under ventilation until Aspergillus niger mycelium forms on the surface of the material. In the second stage, a suspension of Aspergillus cristatus spores is introduced into the material that has undergone the first stage of fermentation, and it is transferred to a sealed container to continue to ferment under static conditions to obtain fermented material. S5: Spread the fermented material on a drying tray, dry it in a ventilated environment, then gather it up and place it in a ventilated environment for aging to obtain the silkworm excrement Liubao tea product.

[0008] Preferably, in step S1, the silkworm excrement is air-dried to a moisture content of 25%-30%, and a suspension of *Lactobacillus plantarum* is sprayed onto the surface of the air-dried silkworm excrement. The viable count of the *Lactobacillus plantarum* suspension is 1×10⁻⁶. 8 CFU / mL up to 5×10 8 The concentration of CFU / mL is sprayed at a rate of 3%-5% of the silkworm excrement mass. After spraying, the mixture is stirred to ensure that the bacterial solution adheres evenly to the surface of the silkworm excrement. The silkworm excrement is then placed in a ventilated fermentation device and undergoes initial fermentation at 28℃-32℃ for 36-48 hours. During the initial fermentation, the mixture is stirred every 6-8 hours, and the relative humidity inside the fermentation device is maintained at 70%-80%. The ventilation rate of the ventilated fermentation device is 0.1-0.3 liters per kilogram of silkworm excrement per minute to obtain the initial fermented silkworm excrement.

[0009] Preferably, during the initial fermentation process, when the pH value of the initial fermented silkworm excrement drops to 4.2-4.6 and the skatole content in the initial fermented silkworm excrement decreases by 45%-55% compared to the silkworm excrement after air drying in step S1, the initial fermentation is terminated. Two hours before the end of the initial fermentation, ventilation is stopped and the initial fermented silkworm excrement is compacted to create a local anaerobic environment inside the initial fermented silkworm excrement, which promotes the production of phenyllactic acid by Lactobacillus plantarum.

[0010] Preferably, in step S2, the primary fermented silkworm excrement is first added to slightly acidic electrolyzed water at a temperature of 30℃-35℃, wherein the pH value of the slightly acidic electrolyzed water is 5.0-6.0, the effective chlorine concentration is 10 mg / L-30 mg / L, and the mass ratio of the primary fermented silkworm excrement to the slightly acidic electrolyzed water is 1:4-1:6. The mixture is stirred for 10-15 minutes, then allowed to stand for 20-30 minutes, and the supernatant is discharged. The precipitate is then added to clean water at a temperature of 20℃-25℃, stirred for 5-8 minutes, allowed to stand for 10-15 minutes, and the supernatant is discharged. Finally, the precipitate is placed in a centrifuge and centrifuged at a speed of 800 r / min-1000 r / min for 3-5 minutes to obtain rinsed silkworm excrement. Slightly acidic electrolyzed water is prepared through the following method: A 0.08% (w / w) dilute hydrochloric acid solution was injected into a diaphragm-free electrolytic cell, using platinum-titanium alloy electrodes as the anode and cathode, at a current density of 15 mA / cm². 2 Electrolyze for 6 minutes under the specified conditions, continuously stirring the dilute hydrochloric acid solution during the electrolysis process. After the electrolysis is completed, let the resulting electrolyzed water stand in a sealed container away from light for 10 minutes to obtain slightly acidic electrolyzed water with a pH of 5.5 and an effective chlorine concentration of 20 mg / L, which is used for the first rinsing of the initially fermented silkworm excrement in step S2.

[0011] Preferably, in step S3, the mulberry leaves and tea leaves are sprayed with clean water to rehydrate to a moisture content of 15%-20%. Then, the washed silkworm excrement, rehydrated mulberry leaves, and rehydrated tea leaves are layered in a mass ratio of 2:2:6. First, one-third of the mass of the rehydrated tea leaves is laid out, then the mixture of all the washed silkworm excrement and all the rehydrated mulberry leaves is laid out, and finally the remaining two-thirds of the mass of the rehydrated tea leaves is laid out. The three layers of materials are then turned over 3-5 times, each time for 1-2 minutes, until the materials are uniform in color and free of lumps, resulting in a mixture with a moisture content of 30%-35%.

[0012] Preferably, in the first stage of step S4, a suspension of Aspergillus niger spores is sprayed onto the mixture, wherein the spore concentration of the Aspergillus niger spore suspension is 1×10⁻⁶. 7 Cells / mL to 3×10 7Spray at a concentration of spores / mL, at a rate of 5%-8% of the mass of the mixture. After spraying, stir to ensure the spore suspension adheres evenly. Then, spread the mixture evenly in a fermentation tray with a layer thickness of 8-12 cm. Place the tray in a ventilated fermentation chamber with a temperature of 30-34℃, a relative humidity of 85%-90%, and a ventilation rate of 0.3-0.5 liters per minute per kilogram of mixture. Allow the mixture to ferment for 48-60 hours until Aspergillus niger mycelium forms on the surface of the mixture, covering 50%-70% of the surface area of ​​the mixture.

[0013] Preferably, in the second stage of step S4, when the area covered by Aspergillus niger mycelium on the surface of the mixture reaches 50%-70% of the surface area of ​​the mixture, the mixture is turned over to mix the internal material with the surface mycelium. Then, a suspension of Aspergillus cristatus spores is sprayed onto the turned-over mixture, wherein the spore concentration of the Aspergillus cristatus spore suspension is 2×10⁻⁶. 7 Cells / mL to 4×10 7 Spray at a rate of 6%-9% of the mass of the mixture, then mix again and transfer to a sealed container. The temperature inside the sealed container should be 28℃-32℃ and the relative humidity should be 80%-85%. Let it ferment for 7-9 days, opening the container every 2-3 days for 5-10 minutes each time.

[0014] As a preferred method, during the closed-container static fermentation process, on the 3rd to 5th day of static fermentation, when the oxygen concentration inside the closed container drops to 5%-8%, air filtered through a 0.22 μm filter membrane is introduced into the closed container to restore the oxygen concentration to 15%-18%. After aeration, the closed-container static fermentation continues. On the 6th to 7th day of static fermentation, the temperature inside the closed container is adjusted to 24℃-26℃, and the relative humidity is adjusted to 75%-80%. Static fermentation continues until the theabrownin content in the fermented material reaches 2-2.5 times the initial theabrownin content of the mixed material, thus obtaining the fermented material.

[0015] Preferably, in step S5, the fermented material is first spread on a drying tray to a thickness of 2-3 cm. The drying tray is then placed in a ventilated drying room with a temperature of 30-35°C and a relative humidity of 50%-60%. The ventilation rate is 0.5-0.8 liters per kilogram of fermented material per minute. The material is dried for 12-18 hours, turning it over every 4-5 hours during the drying process to reduce the moisture content of the fermented material to 18%-22%. The dried fermented material is then collected and placed in a bamboo basket lined with cotton paper. The basket is then placed in an aging room with a temperature of 28-30°C and a relative humidity of 65%-70% for 20-30 days. During the aging process, the fermented material in the bamboo basket is emptied and turned over every 5-6 days. After turning, the material is put back into the bamboo basket to obtain the silkworm excrement Liubao tea product.

[0016] This application also provides a silkworm excrement Liubao tea product, which is produced by the production method provided by any of the above-mentioned schemes and preferred schemes.

[0017] This invention includes at least the following beneficial effects: (1) Through primary fermentation with Lactobacillus plantarum, rinsing with clean water, mixing of raw materials, secondary fermentation with Aspergillus niger and Aspergillus cristatus in stages, and low-temperature drying and aging, Escherichia coli and mold in silkworm excrement are effectively inhibited, the fishy smell of silkworm excrement is significantly reduced, and the content of tea pigments is significantly increased. The product is superior to traditional silkworm excrement tea in terms of safety, flavor and functional components; (2) By controlling the moisture content of silkworm excrement, the amount of Lactobacillus plantarum inoculation, temperature, humidity and ventilation, and creating a local anaerobic environment before the end of primary fermentation to promote the generation of phenyl lactic acid, the microbial safety of primary fermented silkworm excrement is further improved, making the inhibition effect of harmful bacteria and the removal effect of odor more stable, and the degree of primary fermentation between different batches tends to be consistent; (3) By using slightly acidic electrolyzed water rinsing and layered mixing, the microbial load on the surface of silkworm excrement is reduced, and excessive organic acids and water-soluble odor substances are removed, while the mixing is made more consistent. The uniform distribution of moisture content in the mixed materials provides a stable substrate for the uniform growth of microorganisms in the secondary fermentation; (4) The timing of inoculation, fermentation environment, oxygen concentration regulation and fermentation endpoint judgment of Aspergillus niger and Aspergillus cristatus in the secondary fermentation are precisely controlled so that after Aspergillus niger degrades the crude fiber and protein of silkworm excrement, Aspergillus cristatus can make full use of the degradation products to transform tea pigments, the efficiency of theaflavin, thearubigin and theabrownin production is improved, the aged aroma and tea aroma of the product are enhanced, the fishy smell of silkworm excrement is further reduced, and the controllability and batch consistency of the fermentation process are significantly improved; (5) Low temperature thin layer ventilation drying and bamboo basket lining with cotton paper are used for aging, which avoids the surface hardening and flavor loss caused by high temperature drying, so that the moisture content of the product decreases uniformly, the residual enzyme activity and microbial metabolism proceed smoothly during aging, the aged aroma and medicinal aroma gradually accumulate, and the aroma purity, taste mellowness and storage stability of the final product are improved. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the principle of the method of the present invention. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0020] like Figure 1 As shown, the present invention provides a method for producing Liubao tea products containing silkworm excrement, comprising the following steps: Step S1: Place the silkworm excrement in a well-ventilated, shady place to air dry naturally, allowing surface moisture to dissipate slowly. Avoid direct sunlight, which could degrade functional components. During the air-drying process, turn the excrement periodically to ensure uniform moisture content. The final moisture content should be controlled at 25%–30%, providing suitable water activity for subsequent microbial growth while preventing contamination from excessive moisture. Inoculate the air-dried silkworm excrement with *Lactobacillus plantarum*, a facultative anaerobic lactic acid bacterium. This bacterium lowers the pH of the silkworm excrement's microenvironment, thereby inhibiting the growth of harmful microorganisms such as *Escherichia coli* and mold. Simultaneously, the organic acids and bacteriocins produced by *Lactobacillus plantarum* metabolism can react with odor components such as skatole and indole, achieving odor transformation and masking. Inoculation is performed by spraying the bacterial solution followed by turning, ensuring the solution adheres evenly to the surface of the silkworm excrement particles. After inoculation, the silkworm excrement is placed under ventilated conditions for initial fermentation. Ventilation provides sufficient oxygen for the aerobic metabolism of *Lactobacillus plantarum* to maintain its growth vitality and also promptly removes carbon dioxide and volatile odor substances produced during fermentation. During the initial fermentation process, Lactobacillus plantarum can gradually form a dominant bacterial community on the surface of silkworm excrement, which initially degrades proteins and sulfur-containing compounds in the silkworm excrement that are prone to producing odors, thus obtaining initially fermented silkworm excrement. The endpoint of the initial fermentation can be determined based on the decrease in pH value or the removal rate of odor substances.

[0021] Step S2: Add the initially fermented silkworm excrement to clean water, stir to ensure the excrement particles are fully in contact with the water, and allow it to settle. After settling, allow suspended solids and soluble impurities to settle completely, then drain the supernatant to remove some metabolic byproducts and free microorganisms produced during the initial fermentation stage. This rinsing step effectively removes unfixed lactic acid, free amino acids, small peptides, and detached microorganisms from the surface of the initially fermented silkworm excrement, reducing the organic acid content of subsequent mixtures and preventing excessive acidity in the early stages of secondary fermentation from inhibiting the germination of Aspergillus niger and Aspergillus cristatus spores. The temperature of the rinsing water can be controlled between 20℃ and 35℃. The stirring and settling times can be adjusted flexibly according to the impurity content of the initially fermented silkworm excrement. The rinsed silkworm excrement retains a suitable moisture content after rinsing.

[0022] Step S3: Mix the rinsed silkworm excrement, mulberry leaves, and tea leaves in a mass ratio of 2:2:6. The silkworm excrement and mulberry leaves, as functional auxiliary materials, account for 40% of the total, while the tea leaves, as the fermentation substrate and flavor base, account for 60%, thus balancing the product's health benefits and flavor. Both mulberry leaves and tea leaves are plant-based raw materials, which can absorb some of the free moisture carried by the rinsed silkworm excrement and undergo synergistic transformation with the silkworm excrement components during subsequent fermentation. The mixing process employs a layered layering and turning method, gradually adapting the three raw materials in terms of particle size, moisture content, and surface properties, avoiding direct mechanical stirring that could lead to broken tea leaves and clumping of silkworm excrement. The resulting mixture has a uniform moisture content and texture.

[0023] Step S4: The mixture undergoes a two-stage fermentation process, specifically including a first-stage aerobic fermentation and a second-stage closed fermentation. In the first stage, a suspension of Aspergillus niger spores is introduced into the mixture. Aspergillus niger is an aerobic filamentous fungus that secretes various extracellular enzymes such as cellulase, protease, and pectinase to degrade crude fiber and residual protein in silkworm excrement, while simultaneously breaking down cell wall components of mulberry leaves and tea leaves, releasing active ingredients such as polyphenols and flavonoids. Continuous ventilation is maintained during fermentation to ensure a sufficient oxygen supply, promoting spore germination and mycelial growth. The first stage of fermentation is complete when obvious Aspergillus niger mycelium forms on the surface of the material. At this point, Aspergillus niger has initially established a growth advantage and completed the enzymatic hydrolysis of the material's surface structure. In the second stage, a suspension of Aspergillus cristatus spores is introduced into the material fermented in the first stage. Aspergillus cristatus is a characteristic functional microorganism in the aging process of Liubao tea. It can grow in high-humidity environments and produce various extracellular oxidases, promoting the oxidation and polymerization of tea polyphenols to generate functional tea pigments such as theaflavins, thearubigins, and theabrownins. After inoculation, the samples were transferred to a sealed container for static fermentation, restricting free oxygen exchange. This allowed *Aspergillus cristatus* to metabolize under microanaerobic conditions using soluble substrates produced by the early degradation of *Aspergillus niger*, while simultaneously inhibiting the excessive proliferation of aerobic bacteria. The fermented material obtained after the second stage of fermentation showed a significant increase in theabrownin content, complete conversion of animal protein and fiber from silkworm excrement, and a substantial reduction in residual odor substances.

[0024] Step S5: Spread the fermented material evenly on a drying tray, controlling the thickness to ensure that hot air can penetrate the material layer evenly. Use a low-temperature, ventilated drying method to avoid loss of volatile aroma components and degradation of tea pigments. Drying removes excess moisture from the fermented material, stops the metabolic activity of most microorganisms, and reduces the product's moisture content to a safe storage range. After drying, gather the fermented material and place it in a breathable container in a ventilated environment for aging. During aging, residual enzyme activity and low-level microbial metabolism continue to carry out a slow post-ripening reaction, further aging flavor substances, reducing bitterness, and promoting the formation of typical flavors such as aged aroma and medicinal aroma, ultimately yielding the silkworm excrement Liubao tea product.

[0025] This method utilizes primary fermentation with *Lactobacillus plantarum* to remove the off-odor of silkworm excrement and inhibit harmful microorganisms. A rinsing step removes excess organic acids and metabolic residues. Then, silkworm excrement, mulberry leaves, and tea leaves are mixed in a specific ratio, and a secondary fermentation process using *Aspergillus niger* and *Aurogonium cristatum* achieves deep degradation of silkworm excrement fibers and proteins and efficient conversion of tea pigments. Finally, low-temperature drying and ventilated aging stabilize the product quality. Compared to silkworm excrement tea produced using only simple roasting and blending processes, this method significantly reduces the risk of residual harmful microorganisms such as *E. coli* and mold, effectively improves the product flavor, greatly reduces the fishy smell of silkworm excrement, and enhances the aged aroma and tea fragrance. Simultaneously, the tea pigment content is significantly increased, resulting in a marked improvement in the product's safety, flavor quality, and functionality.

[0026] In another technical solution, silkworm excrement is air-dried to a moisture content of 25%–30%, providing suitable water activity for microbial growth and avoiding excessive moisture leading to competitive proliferation of other microorganisms. After spraying with a suspension of *Lactobacillus plantarum*, the mixture is thoroughly stirred to ensure even adhesion of the bacterial solution to the surface of the silkworm excrement particles, avoiding excessively high or low inoculation density in some areas. Primary fermentation is carried out at 28℃–32℃, relative humidity 70%–80%, and a ventilation rate of 0.1–0.3 liters per kilogram of silkworm excrement per minute. This microaerobic ventilation environment meets the metabolic needs of *Lactobacillus plantarum*, and regular stirring prevents material clumping and localized oxygen deficiency. *Lactobacillus plantarum* can rapidly form a dominant bacterial community on the surface of the silkworm excrement, effectively inhibiting the proliferation of harmful microorganisms and initially degrading odor components in the excrement. Compared with natural composting or simple inoculation processes, the microbial safety and odor stability of the primary fermented silkworm excrement are significantly improved.

[0027] In another technical approach, the termination of primary fermentation is determined by a pH value dropping to 4.2-4.6 and a skatole content decreasing by 45%-55% compared to air-dried silkworm excrement. These two indicators are measured using an insertion pH meter and gas chromatography-mass spectrometry (GC-MS), respectively, replacing traditional empirical judgments and effectively improving the consistency of primary fermentation levels between different batches. Two hours before the end of primary fermentation, ventilation is stopped and the silkworm excrement is compacted to create a localized anaerobic environment. This induces *Lactobacillus plantarum* to synthesize phenyllactic acid from the residual substrate. Phenyllactic acid has broad-spectrum antibacterial activity, further enhancing its inhibitory effect on harmful microorganisms such as *Escherichia coli* and molds. The risk of harmful microbial residues in the primary fermented silkworm excrement is further reduced, and the odor removal effect is more stable.

[0028] In another technical solution, in the rinsing process of step S2, the first rinsing uses slightly acidic electrolyzed water at a temperature of 30℃~35℃, a pH value of 5.0~6.0, and an effective chlorine concentration of 10~30 mg / L. The hypochlorous acid component in this water has both oxidizing and antibacterial activity, effectively removing impurities and some microorganisms attached to the surface of the silkworm excrement particles. Simultaneously, oxidation further reduces the residual odor of the silkworm excrement. The mass ratio of the initially fermented silkworm excrement to the slightly acidic electrolyzed water is controlled at 1:4~1:6. After stirring for 10~15 minutes, the mixture is allowed to stand for 20~30 minutes to ensure sufficient contact. The supernatant is then drained to remove dissolved impurities and detached bacteria. The second rinsing uses clean water at 20℃~25℃, stirred for 5~8 minutes, and then allowed to stand for 10~15 minutes to remove residual chlorine and water-soluble impurities. After rinsing, the material is centrifuged at 800~1000 r / min for 3~5 minutes to stabilize the moisture content of the rinsed silkworm excrement at 40%~45%. After rinsing, the microbial load of silkworm excrement is significantly reduced, effectively removing water-soluble odor substances and excess organic acids. The moisture content is uniform and stable, which can significantly improve the uniformity and fermentation safety of subsequent mixed materials in the secondary fermentation process.

[0029] One preferred method for preparing slightly acidic electrolyzed water involves injecting a 0.08% (w / w) dilute hydrochloric acid solution into a diaphragm-free electrolytic cell, using platinum-titanium alloy electrodes as the anode and cathode, and operating at a current density of 15 mA / cm². 2 Electrolysis was performed for 6 minutes under the specified conditions, with continuous stirring of the dilute hydrochloric acid solution during the process. After electrolysis, the solution was allowed to stand in a sealed container in the dark for 10 minutes to obtain slightly acidic electrolyzed water with a pH of 5.5 and an effective chlorine concentration of 20 mg / L. The diaphragm-free electrolysis caused chloride ions in the dilute hydrochloric acid to be oxidized at the anolyte to generate hypochlorous acid. The platinum-titanium alloy electrode is corrosion-resistant and has stable conductivity. Continuous stirring ensured uniform distribution of the electrolysis products, and standing in the dark reduced the decomposition of hypochlorous acid. This slightly acidic electrolyzed water was used for the first rinsing of the initially fermented silkworm excrement in step S2. The oxidizing and antibacterial properties of hypochlorous acid removed microorganisms and some odor substances attached to the surface of the silkworm excrement, while the weakly acidic conditions minimized the damage to the active ingredients in the silkworm excrement. The slightly acidic electrolyzed water prepared in this way can reduce the microbial load of the rinsed silkworm excrement, reduce odor, improve the retention of active ingredients, and make subsequent mixed fermentation cleaner and more stable.

[0030] In another technical solution, in step S3, the mulberry leaves and tea leaves are first rehydrated with clean water to a moisture content of 15%~20%, reducing the moisture content difference between the plant-based raw materials and the washed silkworm excrement, and avoiding uneven moisture transfer during contact between dry and wet materials, which could lead to excessively high or low local humidity. A layered layering process is used during mixing: first, 1 / 3 of the weight of the rehydrated tea leaves is placed at the bottom; then, the mixture of all the washed silkworm excrement and all the rehydrated mulberry leaves is placed in the middle layer; finally, the remaining 2 / 3 of the weight of the rehydrated tea leaves is placed, forming a structure where the tea leaves envelop the silkworm excrement-mulberry leaf mixture. The mixture is then turned over 3~5 times, each time for 1~2 minutes, to ensure thorough and uniform mixing of the three layers. The turning process avoids excessive mechanical shearing that could damage the integrity of the tea leaves, while simultaneously promoting the gradual transfer of moisture carried by the washed silkworm excrement to the mulberry leaves and tea leaves, ultimately stabilizing the moisture content of the mixture at 30%~35%. This method significantly improves the moisture distribution and texture uniformity of the mixture, prevents silkworm excrement from clumping, and ensures that tea leaves and mulberry leaves do not exhibit localized excessive moisture or dryness. It provides stable substrate conditions for the uniform growth of Aspergillus niger and Eurotium cristatum, and significantly improves the uniformity of materials and the consistency of subsequent fermentation.

[0031] In another technical solution, the spore concentration sprayed onto the mixture is 1×10⁻⁶. 7 Cells / mL ~3×10 7Spray a suspension of Aspergillus niger spores at a concentration of 5%–8% of the mixture's mass. After spraying, thoroughly mix the mixture to ensure the spore suspension adheres evenly to the surface of the material particles. Spread the inoculated mixture evenly in a fermentation tray, maintaining a layer thickness of 8–12 cm. Place the tray in a ventilated fermentation chamber at a temperature of 30–34°C, a relative humidity of 85%–90%, and a ventilation rate of 0.3–0.5 liters per minute per kilogram of mixture. Allow the mixture to ferment for 48–60 hours. Adequate ventilation provides sufficient oxygen for Aspergillus niger growth. The combination of a thin substrate layer and suitable temperature and humidity ensures even mycelial expansion on the material surface, preventing localized anaerobic conditions or excessive acid production. The first stage of fermentation is complete when the Aspergillus niger mycelium covers 50%–70% of the total surface area of ​​the mixture. This method allows Aspergillus niger to form a uniform and moderate growth advantage on the surface of the mixture, resulting in more complete initial degradation of fiber and protein, and effective inhibition of the proliferation of harmful bacteria. At the same time, it avoids the sour and musty taste problems caused by excessive local growth of Aspergillus niger in traditional natural inoculation methods, creating stable preconditions for the inoculation of Eurotium cristatum and the conversion of tea pigments in the second stage.

[0032] In another technical solution, when the surface area covered by Aspergillus niger mycelium of the mixture reaches 50% to 70% of the total surface area, the material is first turned over to ensure thorough mixing between the surface-distributed Aspergillus niger mycelium and the internal material. This allows the soluble substrates and enzyme systems produced by the early degradation of Aspergillus niger to be evenly dispersed throughout the entire material system. Subsequently, a suspension of Aspergillus niger spores is sprayed onto the turned-over mixture at a spore concentration of 2 × 10⁻⁶. 7 Cells / mL ~4×10 7 Spray at a concentration of 6%–9% of the mixture's mass, then mix thoroughly again before transferring to a sealed container. *Aspergillus cristatus* is a characteristic functional microorganism in the aging process of Liubao tea. It can grow in high-humidity environments and secrete various extracellular oxidases, promoting the oxidation and polymerization of tea polyphenols to form theaflavins, thearubigins, and theabrownins. Maintain the temperature inside the sealed container at 28℃–32℃ and the relative humidity at 80%–85%. Let it ferment for 7–9 days, opening the container every 2–3 days for 5–10 minutes each time to replenish oxygen and remove metabolically produced carbon dioxide and low-boiling-point odorous substances, preventing excessive anaerobic fermentation and the development of a sour or rancid flavor. This method allows *Aspergillus niger* and *Aspergillus cristatus* to form a sequential fermentation system, significantly improving the conversion efficiency of tea pigments, fully degrading animal protein and fiber in silkworm excrement, resulting in a more prominent aged aroma and tea fragrance, further weakening the fishy smell of silkworm excrement, and significantly improving the flavor quality and fermentation controllability of the product.

[0033] In another technical approach, during the 3rd to 5th day of static fermentation, when the oxygen concentration in the sealed container drops to 5% to 8%, it indicates that *Aspergillus cristatus* has consumed a large amount of oxygen through aerobic metabolism. If not replenished in time, the aerobic metabolic rate will decrease, and anaerobic metabolic products may accumulate and produce a sour odor. At this point, sterile air filtered through a 0.22 μm filter membrane is introduced into the sealed container to prevent the introduction of external bacteria, allowing the oxygen concentration inside the container to recover to 15% to 18%, thus maintaining the metabolic activity of *Aspergillus cristatus*. During the 6th to 7th day of static fermentation, the temperature inside the sealed container is adjusted to 24℃ to 26℃, and the relative humidity is adjusted to 75% to 80%. This stage provides the temperature and humidity conditions of the initial stage of natural aging, gradually reducing the metabolic rate of microorganisms and slowing down the oxidative polymerization reaction, which is conducive to the stable formation of theaflavins. The fermentation endpoint is determined by the theaflavin content in the fermented material reaching 2 to 2.5 times the initial content, replacing the traditional control method that relies solely on fermentation time or sensory experience. This method can effectively avoid off-flavor problems caused by lack of oxygen in the later stage of closed fermentation, make the theabrownin production process more stable, significantly improve the purity of product flavor, and effectively ensure the quality consistency between different batches.

[0034] In another technical solution, after fermentation, the material is first evenly spread on a drying tray, with a thickness controlled at 2-3 cm. This thinner layer allows for even air penetration. The drying chamber temperature is set at 30-35℃, relative humidity at 50-60%, and ventilation at 0.5-0.8 liters per minute per kilogram of fermented material. This creates low-temperature, thin-layer ventilation and drying conditions, allowing moisture to gradually migrate from the interior of the material to the surface and be discharged with the airflow, avoiding surface hardening and internal moisture retention caused by high-temperature rapid drying. During the drying period, the material is turned over every 4-5 hours to prevent clumping and localized over-wetting. After 12-18 hours of drying, the moisture content of the fermented material drops to 18-22%. The dried fermented material is then collected and placed in bamboo baskets lined with cotton paper. The cotton paper regulates the microenvironment inside the basket, absorbing or releasing small amounts of moisture, while the breathability of the bamboo basket itself facilitates the continued activity of residual enzymes and low-level microbial metabolism. The aging chamber temperature is controlled at 28℃~30℃, and the relative humidity at 65%~70%. The aging period is 20~30 days. During this period, the material in the bamboo basket is emptied and turned over every 5~6 days to prevent localized moisture absorption and mold growth, while ensuring even contact between all parts of the material and the air. This method allows for a gentle and stable drying process, gradual mellowing of flavor compounds during the aging stage, slow accumulation of aged and medicinal aromas, good uniformity of product moisture content, and a significantly reduced risk of mold growth. The resulting silkworm excrement Liubao tea product is significantly superior to similar products dried by sun-drying or high-temperature rapid drying in terms of aroma purity, mellow taste, and storage stability.

[0035] This application also provides a silkworm excrement Liubao tea product, which is produced by the production method provided by any of the above-mentioned schemes and preferred schemes.

[0036] To further illustrate the beneficial effects of this application, the following specific embodiments and comparative examples are provided: Example

[0037] Select fresh silkworm excrement and air-dry it in a well-ventilated, shady place until the moisture content reaches 27%. Spray the surface of the air-dried silkworm excrement with a suspension of *Lactobacillus plantarum*, with a viable count of 3 × 10⁻⁶. 8 The concentration of CFU / mL was sprayed at a rate of 4% of the silkworm excrement mass. After thorough mixing, the mixture was placed in a ventilated fermentation device and allowed to undergo initial fermentation for 42 hours at 30°C, 75% relative humidity, and a ventilation rate of 0.2 liters per kilogram of silkworm excrement per minute. During the initial fermentation, the mixture was stirred every 7 hours. The initial fermentation was terminated when the pH dropped to 4.4 and the skatole content decreased by 50% compared to the air-dried silkworm excrement. Ventilation was stopped and the mixture was compacted 2 hours before the end of the fermentation. The initially fermented silkworm excrement was then added to slightly acidic electrolyzed water at 32°C, pH 5.5, and an effective chlorine concentration of 20 mg / L at a mass ratio of 1:5. The mixture was stirred for 12 minutes, allowed to stand for 25 minutes, and the supernatant was drained. The mixture was then rinsed with 22°C clean water, stirred for 6 minutes, allowed to stand for 12 minutes, and the supernatant was drained. The mixture was then centrifuged to remove water until the moisture content reached 42%, yielding rinsed silkworm excrement. Mulberry leaves and tea leaves were separately sprayed to rehydrate to a moisture content of 17%. They were then layered in a 2:2:6 ratio of washed silkworm excrement, mulberry leaves, and tea leaves. One-third of the tea leaves were layered first, followed by the mixture of washed silkworm excrement and mulberry leaves, and finally the remaining two-thirds of the tea leaves. The mixture was stirred four times, 1.5 minutes each time, to obtain a mixture with a moisture content of 32%. The mixture was then sprayed with a suspension of Aspergillus niger spores at a concentration of 2 × 10⁻⁶ spores. 7 Spray at a concentration of 6% (3 × 10⁶ spores / mL) on a fermentation tray, mixing thoroughly. The mixture should be spread evenly to a thickness of 10 cm. Place the tray in a ventilated fermentation chamber at 32°C, 88% relative humidity, and a ventilation rate of 0.4 L / kg / min. Let it ferment for 54 hours, until the Aspergillus niger mycelium covers 60% of the surface. After mixing, spray with a *Aspergillus cristatus* spore suspension at a concentration of 3 × 10⁻⁶ spores / mL. 7 The mixture was sprayed at a concentration of 7% per mL, then stirred again and transferred to a sealed container. It was fermented at 30°C and 82% relative humidity for 8 days, with ventilation every 3 days for 8 minutes each time. On the 4th day, when the oxygen concentration dropped to 6%, air filtered through a 0.22 μm membrane was introduced until the oxygen concentration reached 16%. On the 6th day, the temperature was lowered to 25°C and the relative humidity to 78%, and fermentation continued until the theaflavin content reached 2.2 times that of the initial mixture. The fermented material was spread on a drying tray, 2.5 cm thick, and dried in a drying chamber at 32°C and 55% relative humidity with a ventilation rate of 0.6 L / kg / min for 15 hours, turning it every 4.5 hours until the moisture content reached 20%. The dried material was then collected and placed in a bamboo basket lined with cotton paper. It was aged in an aging chamber at 29°C and 68% relative humidity for 25 days, turning it over every 5 days to obtain the silkworm excrement Liubao tea product.

[0038] Comparative Example 1: It adopts the traditional silkworm excrement tea process. Fresh silkworm excrement is air-dried and then roasted at 70℃ for 30 minutes. It is then directly blended with mulberry leaves and tea leaves in a mass ratio of 2:2:6. After being mixed evenly, it is dried with hot air at 80℃ until the moisture content is 8%. No microbial fermentation or aging is carried out.

[0039] Comparative Example 2: In step S1, instead of inoculating with Lactobacillus plantarum, natural composting is used for initial fermentation. The remaining steps are the same as in Example 1.

[0040] Comparative Example 3: In step S4, the first stage does not involve inoculation with Aspergillus niger spore suspension. The mixture directly proceeds to the second stage for inoculation with Coronavirus cristatum. The remaining steps are the same as in Example 1.

[0041] Comparative Example 4: In step S4, the second stage does not involve inoculation with *Aspergillus cristatus* spore suspension. After the first stage of *Aspergillus niger* is completed, it is directly transferred to a sealed container for static fermentation. The remaining steps are the same as in Example 1.

[0042] Comparative Example 5: Step S5 involves drying with hot air at 80°C to a moisture content of 8%, without ventilation or aging. The remaining steps are the same as in Example 1.

[0043] The finished Liubao tea products obtained in Example 1 and the comparative examples were subjected to index determination. The determination indicators and detection methods included: Escherichia coli was determined according to GB 4789.3; molds and yeasts were determined according to GB 4789.15; Salmonella was determined according to GB 4789.4; Staphylococcus aureus was determined according to GB 4789.10; aflatoxin B1 was determined according to GB 5009.22; organophosphate and pyrethroid pesticide residues were determined according to GB 23200.113 and GB 23200.8; theaflavins, thearubigins, and theabrownins were determined by spectrophotometry; and skatole and indole were determined by gas chromatography-mass spectrometry. Sensory evaluation was conducted by 10 evaluators, with a maximum score of 100 points, evaluating color, aroma, taste, liquor color, and infused leaf appearance.

[0044] The test results for each indicator are as follows: In the silkworm excrement Liubao tea product prepared in Example 1, the levels of Escherichia coli, mold, and yeast were less than 10 CFU / g, and Salmonella and Staphylococcus aureus were not detected. Aflatoxin B1 was not detected. Residues of organophosphates and pyrethroids were not detected. The content of theaflavins was 0.21%, thearubigins was 3.84%, and theabrownins was 14.62%. The skatole content was 0.9 μg / kg, and the indole content was 1.4 μg / kg. The average sensory evaluation score was 91 points.

[0045] In the traditional silkworm excrement tea prepared in Comparative Example 1, the Escherichia coli count was 1.1 × 10⁻⁶. 4 CFU / g, mold count 2.8 × 10⁻⁶ 3 CFU / g, yeast is 1.5×10 3 The CFU / g content was 1.8 μg / kg for aflatoxin B1, 0.04 mg / kg for chlorpyrifos residue, 0.14% for theaflavins, 2.1% for thearubigins, 5.8% for theabrownins, 12.6 μg / kg for skatole, and 14.3 μg / kg for indole. The average sensory evaluation score was 61 points.

[0046] In the silkworm excrement Liubao tea prepared in Comparative Example 2, the Escherichia coli count was 2.3 × 10⁻⁶. 2 CFU / g, mold count: 6.4 × 10⁻⁶ 2 The CFU / g content was 11.5% for theabrownins and 5.8 μg / kg for skatole. The average sensory evaluation score was 73.

[0047] In the silkworm excrement Liubao tea prepared in Comparative Example 3, the levels of Escherichia coli and mold were less than 10 CFU / g, the theaflavins content was 0.16%, thearubigins content was 2.9%, theabrownins content was 8.7%, the skatole content was 3.1 μg / kg, and the average sensory evaluation score was 76 points.

[0048] In the silkworm excrement Liubao tea prepared in Comparative Example 4, the content of Escherichia coli was less than 10 CFU / g, the content of mold was less than 10 CFU / g, the content of theaflavins was 0.18%, the content of thearubigins was 3.2%, the content of theabrownins was 9.9%, the content of skatole was 2.4 μg / kg, and the average sensory evaluation score was 79 points.

[0049] In the silkworm excrement Liubao tea prepared in Comparative Example 5, the levels of Escherichia coli were less than 10 CFU / g, the levels of mold were less than 10 CFU / g, the content of theaflavins was 12.1%, the content of skatole was 1.3 μg / kg, and the average sensory evaluation score was 82 points.

[0050] Analysis of the above data shows that, compared with Comparative Example 1, the number of harmful microorganisms in Example 1 decreased from 10. 4The CFU / g level decreased to below the detection limit, aflatoxin B1 decreased from 1.8 μg / kg to undetectable levels, and chlorpyrifos decreased from 0.04 mg / kg to undetectable levels. "Undetectable levels" does not mean completely absent, but rather below the specified limit of detection (LOD), meaning the target substance was not detected. Theabrownin content increased from 5.8% to 14.62%, with corresponding increases in theaflavins and thearubigins. Skatole content decreased from 12.6 μg / kg to 0.9 μg / kg, and indole decreased from 14.3 μg / kg to 1.4 μg / kg. The sensory evaluation score improved from 61 to 91. These improvements are related to the combined effects of the initial fermentation by *Lactobacillus plantarum* inhibiting harmful microorganisms, rinsing with slightly acidic electrolyzed water removing surface contaminants, the staged fermentation by *Aspergillus niger* and *Aurogonium cristatum* promoting tea pigment production, and low-temperature aging enhancing flavor.

[0051] Because Comparative Example 2 was not inoculated with *Lactobacillus plantarum*, lactic acid bacteria failed to form a dominant flora during the initial fermentation stage. The residual levels of *Escherichia coli* and mold were significantly higher than in Example 1, and the skatole content was more than six times that of Example 1. This indicates that the initial fermentation with *Lactobacillus plantarum* plays a crucial role in the safety of silkworm excrement and the removal of odors. This result is consistent with existing research conclusions that *Lactobacillus plantarum* can reduce the release of skatole and indole.

[0052] Comparative Example 3, without inoculation with *Aspergillus niger*, showed insufficient degradation of crude fiber and protein in silkworm excrement, with a theabrownin content of 8.7%, lower than the 14.62% in Example 1. The *Aspergillus niger* strain screened from silkworm excrement, under optimized conditions, exhibited cellulase activity up to 77.35 U / mL, effectively degrading silkworm excrement fiber. The results of this comparative example demonstrate that the first-stage fermentation of *Aspergillus niger* provides the necessary soluble substrate for subsequent theabrownin conversion.

[0053] Comparative Example 4, without inoculation with *Aspergillus cristatus*, showed insufficient oxidation and polymerization of tea polyphenols, with a theabrownin content of 9.9%, lower than that of Example 1. Previous studies have shown that *Aspergillus cristatus* fermentation can increase theabrownin content. This comparative example demonstrates that the second-stage fermentation of *Aspergillus cristatus* plays a crucial role in the final amount of tea pigments produced.

[0054] Comparative Example 5, dried with hot air at 80℃ without ventilation aging, had a theabrownin content of 12.1% and a sensory evaluation score of 82, both lower than Example 1. This comparative example demonstrates that low-temperature ventilation drying and bamboo basket aging significantly contribute to the further accumulation of theabrownins and flavor aging. The theabrownin content of Liubao tea after 60 days of pile fermentation was approximately 16.49%, while this example achieved 14.62% within a shorter fermentation and aging period, indicating that the staged inoculation of Aspergillus niger and Aspergillus cristatus promotes theabrownin production.

[0055] The above results demonstrate that the steps of this invention work together to solve the problems of insufficient safety, residual odor, and low conversion efficiency of tea pigments in traditional silkworm excrement tea.

[0056] It should be noted that although the steps are described in a specific order above, this does not mean that they must be performed in that order. In fact, some of these steps can be executed concurrently, or even in a different order, as long as the required functionality is achieved. The number of devices and processing scale described herein are for simplification of the invention; applications, modifications, and variations of this invention will be readily apparent to those skilled in the art.

[0057] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for producing Liubao tea products containing silkworm excrement, characterized in that, Includes the following steps: S1: Dry the silkworm excrement in the shade, inoculate the dried silkworm excrement with Lactobacillus plantarum, and carry out primary fermentation under ventilated conditions to obtain primary fermented silkworm excrement; S2: Add the primary fermented silkworm excrement to clean water, stir and let stand, drain the supernatant to obtain rinsed silkworm excrement; S3: Mix the rinsed silkworm excrement, mulberry leaves and tea leaves in a mass ratio of 2:2:6 to obtain a mixture; S4: The mixture is subjected to secondary fermentation, which includes a first stage and a second stage. In the first stage, a suspension of Aspergillus niger spores is introduced into the mixture, and it is allowed to ferment under ventilation until Aspergillus niger mycelium forms on the surface of the material. In the second stage, a suspension of Aspergillus cristatus spores is introduced into the material that has undergone the first stage of fermentation, and it is transferred to a sealed container to continue to ferment under static conditions to obtain fermented material. S5: Spread the fermented material on a drying tray, dry it in a ventilated environment, then gather it up and place it in a ventilated environment for aging to obtain the silkworm excrement Liubao tea product.

2. The method for producing a silkworm excrement Liubao tea product according to claim 1, characterized in that, In step S1, silkworm excrement is air-dried to a moisture content of 25%-30%, and then a suspension of *Lactobacillus plantarum* is sprayed onto the surface of the air-dried excrement. The viable count of the *Lactobacillus plantarum* suspension is 1×10⁻⁶. 8 CFU / mL up to 5×10 8 The concentration of CFU / mL is sprayed at a rate of 3%-5% of the silkworm excrement mass. After spraying, the mixture is stirred to ensure that the bacterial solution adheres evenly to the surface of the silkworm excrement. The silkworm excrement is then placed in a ventilated fermentation device and undergoes initial fermentation at 28℃-32℃ for 36-48 hours. During the initial fermentation, the mixture is stirred every 6-8 hours, and the relative humidity inside the fermentation device is maintained at 70%-80%. The ventilation rate of the ventilated fermentation device is 0.1-0.3 liters per kilogram of silkworm excrement per minute, resulting in initially fermented silkworm excrement.

3. The method for producing a silkworm excrement Liubao tea product according to claim 2, characterized in that, During the initial fermentation process, when the pH value of the initial fermented silkworm excrement drops to 4.2-4.6 and the skatole content in the initial fermented silkworm excrement decreases by 45%-55% compared to the silkworm excrement after air drying in step S1, the initial fermentation is terminated. Two hours before the end of the initial fermentation, ventilation is stopped and the initial fermented silkworm excrement is compacted to create a local anaerobic environment inside the initial fermented silkworm excrement, which promotes the production of phenyllactic acid by Lactobacillus plantarum.

4. The method for producing a silkworm excrement Liubao tea product according to claim 1, characterized in that, In step S2, the primary fermented silkworm excrement is first added to slightly acidic electrolyzed water at a temperature of 30℃-35℃. The pH value of the slightly acidic electrolyzed water is 5.0-6.0, the effective chlorine concentration is 10 mg / L-30 mg / L, and the mass ratio of the primary fermented silkworm excrement to the slightly acidic electrolyzed water is 1:4-1:

6. The mixture is stirred for 10-15 minutes, then allowed to stand for 20-30 minutes, and the supernatant is discharged. The precipitate is then added to clean water at a temperature of 20℃-25℃, stirred for 5-8 minutes, allowed to stand for 10-15 minutes, and the supernatant is discharged. Finally, the precipitate is placed in a centrifuge and centrifuged at a speed of 800 r / min-1000 r / min for 3-5 minutes to obtain rinsed silkworm excrement. Slightly acidic electrolyzed water is prepared through the following method: A 0.08% (w / w) dilute hydrochloric acid solution was injected into a diaphragm-free electrolytic cell, using platinum-titanium alloy electrodes as the anode and cathode, at a current density of 15 mA / cm². 2 Electrolyze for 6 minutes under the specified conditions, continuously stirring the dilute hydrochloric acid solution during the electrolysis process. After the electrolysis is completed, let the resulting electrolyzed water stand in a sealed container away from light for 10 minutes to obtain slightly acidic electrolyzed water with a pH of 5.5 and an effective chlorine concentration of 20 mg / L, which is used for the first rinsing of the initially fermented silkworm excrement in step S2.

5. The method for producing a silkworm excrement Liubao tea product according to claim 1, characterized in that, In step S3, the mulberry leaves and tea leaves are sprayed with clean water to rehydrate to a moisture content of 15%-20%. Then, the washed silkworm excrement, rehydrated mulberry leaves, and rehydrated tea leaves are layered in a mass ratio of 2:2:

6. First, one-third of the mass of the rehydrated tea leaves is laid out, then the mixture of all the washed silkworm excrement and all the rehydrated mulberry leaves is laid out, and finally the remaining two-thirds of the mass of the rehydrated tea leaves is laid out. The three layers of materials are then turned over 3-5 times, each time for 1-2 minutes, until the materials are uniform in color and free of lumps, resulting in a mixture with a moisture content of 30%-35%.

6. The method for producing a silkworm excrement Liubao tea product according to claim 1, characterized in that, In the first stage of step S4, a suspension of Aspergillus niger spores is sprayed onto the mixture, wherein the spore concentration of the Aspergillus niger spore suspension is 1×10⁻⁶. 7 Cells / mL to 3×10 7 Spray at a concentration of spores / mL, at a rate of 5%-8% of the mass of the mixture. After spraying, stir to ensure the spore suspension adheres evenly. Then, spread the mixture evenly in a fermentation tray with a layer thickness of 8-12 cm. Place the tray in a ventilated fermentation chamber with a temperature of 30-34℃, a relative humidity of 85%-90%, and a ventilation rate of 0.3-0.5 liters per minute per kilogram of mixture. Allow the mixture to ferment for 48-60 hours until Aspergillus niger mycelium forms on the surface of the mixture, covering 50%-70% of the surface area of ​​the mixture.

7. The method for producing a silkworm excrement Liubao tea product according to claim 6, characterized in that, In the second stage of step S4, when the surface area covered by Aspergillus niger mycelium of the mixture reaches 50%-70% of the surface area of ​​the mixture, the mixture is turned over to mix the internal material with the surface mycelium. Then, a suspension of Aspergillus cristatus spores is sprayed onto the turned-over mixture. The spore concentration of the Aspergillus cristatus spore suspension is 2×10⁻⁶. 7 Cells / mL to 4×10 7 Spray at a rate of 6%-9% of the mass of the mixture, then mix again and transfer to a sealed container. The temperature inside the sealed container should be 28℃-32℃ and the relative humidity should be 80%-85%. Let it ferment for 7-9 days, opening the container every 2-3 days for 5-10 minutes each time.

8. The method for producing a silkworm excrement Liubao tea product according to claim 7, characterized in that, During the closed-container static fermentation process, from the 3rd to the 5th day of static fermentation, when the oxygen concentration inside the closed container drops to 5%-8%, air filtered through a 0.22 μm filter membrane is introduced into the closed container to restore the oxygen concentration to 15%-18%. After aeration, the closed-container static fermentation continues. From the 6th to the 7th day of static fermentation, the temperature inside the closed container is adjusted to 24℃-26℃, and the relative humidity is adjusted to 75%-80%. Static fermentation continues until the theabrownin content in the fermented material reaches 2-2.5 times the initial theabrownin content of the mixed material, thus obtaining the fermented material.

9. The method for producing a silkworm excrement Liubao tea product according to claim 1, characterized in that, In step S5, the fermented material is first spread on a drying tray to a thickness of 2-3 cm. The drying tray is placed in a ventilated drying room with a temperature of 30-35℃ and a relative humidity of 50%-60%. The ventilation rate is 0.5-0.8 liters per kilogram of fermented material per minute. The material is dried for 12-18 hours, turning it over every 4-5 hours during the drying process to reduce the moisture content of the fermented material to 18%-22%. Then, the dried fermented material is collected and placed in a bamboo basket lined with cotton paper. The basket is placed in an aging room with a temperature of 28-30℃ and a relative humidity of 65%-70% for 20-30 days. During the aging process, the fermented material in the bamboo basket is emptied and turned over every 5-6 days. After turning, the material is put back into the bamboo basket to obtain the silkworm excrement Liubao tea product.

10. A type of Liubao tea product made from silkworm excrement, characterized in that, It is manufactured using the manufacturing method described in any one of claims 1-9.

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