Processing method for clean fermentation of tea leaves

Abstract

The invention relates to the technical field of tea leaf processing, in particular to a tea leaf clean fermentation processing method which comprises the following steps: raw material selection, fixation treatment, rolling and humidification, constant-temperature fermentation and microbial regulation, drying and nitrogen protection, ultrasonic cleaning pretreatment, infrared preheating treatment, circulating filtration and gas purification, and vacuum packaging and gas replacement. Real-time monitoring and intelligent control are realized; the processing method for clean fermentation of the tea leaves, provided by the invention, has the beneficial effects that the fermentation process of the tea leaves is more stable and controllable by accurately controlling parameters such as temperature, humidity and time in the processing process and introducing biological regulation means such as beneficial microorganisms and enzyme preparations, so that the quality and taste of the tea leaves are improved.

Description

Technical Field

[0001] The invention relates to the field of tea processing, in particular to a processing method for clean fermentation of tea. Background Art

[0002] Tea is a beverage that is loved by consumers all over the world. Its quality is closely related to its processing methods. Traditional tea fermentation processing methods often cause environmental pollution, unstable tea quality, and difficulty in controlling the fermentation process. With the advancement of science and technology and the improvement of consumers' requirements for food safety and quality, the tea processing industry is in urgent need of a clean, efficient, and intelligent processing method.

[0003] Traditional tea fermentation processing methods mainly rely on manual control and empirical judgment. Fluctuations in parameters such as temperature, humidity, and time during the processing process will have a significant impact on the quality of tea. In addition, traditional processing methods often lack effective waste treatment measures, leading to environmental pollution and waste of resources.

[0004] Therefore, it is particularly important to develop a clean tea fermentation processing method that can accurately control processing parameters, improve tea quality, and reduce environmental pollution. Summary of the invention

[0005] The object of the present invention is to provide a processing method for clean fermentation of tea leaves to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a processing method for clean fermentation of tea leaves, the method comprising the following steps: a) Raw material selection: fresh, pest-free and pollution-free tea leaves are selected as raw materials, and the moisture content of the tea leaves is controlled at 68%-72%; b) Withering treatment: The tea leaves are withered at a temperature of 165-175°C for 2.5-3.5 minutes, and 0.8-1.2 cubic meters per minute of oxygen is introduced into the withering machine to reduce the enzyme activity in the tea leaves to below 45%; c) Rolling and humidification: Roll the tea leaves after withering, with a rolling force of 7-9 kg / cm2 for no less than 35 minutes, and spray 0.075-0.095 liters of water mist per kilogram of tea leaves evenly into the rolling machine during the rolling process; d) Constant temperature fermentation and microbial regulation: The rolled tea leaves are placed in a constant temperature fermentation room, the temperature in the fermentation room is controlled at 29℃-31℃, the humidity is controlled at 78%-82%, and gas containing 106.5 CFU / m3 of beneficial microorganisms is introduced into the fermentation room, and the fermentation time is not less than 50 hours; e) Drying and nitrogen protection: Dry the fermented tea leaves at a temperature of 85-95°C and a drying time of 1.2-1.8 hours to reduce the moisture content of the tea leaves to 6%-7%. During the drying process, nitrogen gas of 0.4-0.7 cubic meters per minute is introduced into the dryer. f) Ultrasonic cleaning pretreatment: before the raw material selection step a), the tea leaves are subjected to ultrasonic cleaning treatment, the ultrasonic frequency is controlled at 25-35kHz, and the cleaning time is not less than 7 minutes; g) Infrared preheating treatment: after the rolling step c) and before the constant temperature fermentation step d), the tea leaves are subjected to infrared preheating treatment, the preheating temperature is controlled at 38°C-42°C, and the preheating time is not less than 12 minutes; h) Circulation filtration and gas purification: In the constant temperature fermentation step d), the gas in the fermentation chamber is subjected to circulation filtration treatment with a filtration accuracy of not less than 0.25 microns, and an activated carbon adsorption device is used to remove odor and harmful substances in the gas; i) Vacuum packaging and gas replacement: After the drying step e), the tea leaves are vacuum packaged, the oxygen content in the package is controlled to be below 0.5%, and a nitrogen replacement device is used to replace the residual oxygen in the package with nitrogen; j) Real-time monitoring and intelligent control: Real-time monitoring and recording of each step in the processing, including temperature, humidity, time, and gas concentration parameters, and automatic adjustment of processing parameters through an intelligent control system to ensure the stability and controllability of the processing.

[0007] Preferably, in the fixing step b), it also includes spraying a proper amount of antioxidant into the fixing machine, and the amount of antioxidant is controlled at 0.01-0.02 grams per kilogram of tea leaves to further reduce the enzyme activity in the tea leaves.

[0008] Preferably, in the rolling and humidifying step c), a proper amount of natural plant extract is added into the rolling machine, and the amount of the extract is controlled to be 0.1-0.2 grams per kilogram of tea leaves to improve the taste and aroma of the tea leaves.

[0009] Preferably, in the constant temperature fermentation and microbial regulation step d), it also includes adding a proper amount of enzyme preparation into the fermentation chamber, and the amount of enzyme preparation is controlled at 0.005-0.01 grams per kilogram of tea leaves to promote the substance conversion and fermentation process in the tea leaves.

[0010] Preferably, in the drying and nitrogen protection step e), a proper amount of moisturizing agent is sprayed into the dryer, and the amount of moisturizing agent is controlled to be 0.002-0.005 grams per kilogram of tea leaves to maintain the moisture balance of the tea leaves during the drying process.

[0011] Preferably, in the ultrasonic cleaning pretreatment step f), a suitable amount of antibacterial agent is added to the cleaning solution, and the concentration of the antibacterial agent is controlled at 0.01%-0.05% to kill microorganisms on the surface of the tea leaves.

[0012] Preferably, in the infrared preheating treatment step g), the preheating temperature is also included in a gradient control, the preheating temperature is gradually increased from 36° C. to 40° C., and the preheating time is not less than 15 minutes, so as to better meet the preheating requirements of the tea leaves.

[0013] Preferably, in the circulating filtration and gas purification step h), the filtered gas is also sterilized, the sterilization temperature is controlled at 70° C.-80° C., and the sterilization time is not less than 5 minutes to kill microorganisms in the gas.

[0014] Preferably, in the vacuum packaging and gas replacement step i), the packaging material is also pretreated, and the pretreatment includes coating a layer of air-permeable but water-impermeable coating on the surface of the packaging material to improve the sealing and preservation effect of the packaging.

[0015] Preferably, the method also includes recycling and treating waste generated during the processing, including tea leaves, waste water, and waste gas, which are converted into harmless substances or resources for reuse through biodegradation, chemical treatment or physical separation.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The processing method for clean fermentation of tea leaves proposed in the present invention makes the fermentation process of tea leaves more stable and controllable by precisely controlling parameters such as temperature, humidity, time and the like during the processing, and introducing biological control means such as beneficial microorganisms and enzyme preparations, thereby improving the quality and taste of tea leaves.

[0017] During the processing, the emission of waste gas, waste water, tea leaves and other wastes are effectively reduced through measures such as circulation filtration and gas purification, vacuum packaging and gas replacement. At the same time, the recycling of resources is achieved and pollution to the environment is reduced.

[0018] The intelligent control system is used to monitor and automatically adjust the processing process in real time, reducing human intervention and errors, and improving processing efficiency and automation level.

[0019] Ultrasonic cleaning and antimicrobial treatment are introduced during the processing to effectively kill microorganisms and harmful substances on the surface of tea leaves, thus improving the safety and sanitary quality of tea leaves. Through measures such as waste recycling and treatment, the recycling of resources and the sustainable development of the industry have been achieved, which is in line with the current green, environmentally friendly and low-carbon development trend. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose and technical solution of the present invention clearly and completely described, and the advantages more clearly understood, the embodiments of the present invention are further described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] For example, see Figure 1 The present invention provides a technical solution: a processing method for clean fermentation of tea leaves.

[0022] Raw material selection: Fresh, pest-free and pollution-free Longjing tea is used as the raw material, and the moisture content of the tea is controlled at 70%.

[0023] Withering treatment: The tea leaves are withered at a temperature of 170°C for 3 minutes. At the same time, 1 cubic meter / minute of oxygen is introduced into the withering machine to reduce the enzyme activity in the tea leaves to below 45%.

[0024] Rolling and humidification: Roll the tea leaves after withering, and control the rolling force at 8 kg / cm2 for 40 minutes. During the rolling process, spray 0.085 liters of water mist per kilogram of tea evenly into the rolling machine.

[0025] Constant temperature fermentation and microbial regulation: The rolled tea leaves are placed in a constant temperature fermentation room. The temperature in the fermentation room is controlled at 30°C and the humidity is controlled at 80%. At the same time, gas containing 10^6.5 CFU / cubic meter of beneficial microorganisms is introduced into the fermentation room. The fermentation time is 55 hours.

[0026] Drying and nitrogen protection: Dry the fermented tea leaves at a temperature of 90°C for 1.5 hours to reduce the moisture content of the tea leaves to 6.5%. During the drying process, introduce 0.5 cubic meters per minute of nitrogen into the dryer.

[0027] Ultrasonic cleaning pretreatment: Before the raw material selection step, the tea leaves are subjected to ultrasonic cleaning treatment, the ultrasonic frequency is controlled at 30kHz, and the cleaning time is 8 minutes.

[0028] Infrared preheating treatment: After the rolling step and before the constant temperature fermentation step, the tea leaves are subjected to infrared preheating treatment, with the preheating temperature controlled at 40°C and the preheating time being 12 minutes.

[0029] Circulation filtration and gas purification: During the constant temperature fermentation step, the gas in the fermentation chamber is circulated and filtered with a filtration accuracy of 0.25 microns, and an activated carbon adsorption device is used to remove odors and harmful substances in the gas.

[0030] Vacuum packaging and gas replacement: After the drying step, the tea leaves are vacuum packaged, the oxygen content in the package is controlled at 0.4%, and a nitrogen replacement device is used to replace the residual oxygen in the package with nitrogen.

[0031] Real-time monitoring and intelligent control: Real-time monitoring and recording of each step in the processing process, including temperature, humidity, time, gas concentration and other parameters, and automatic adjustment of processing parameters through intelligent control systems.

[0032] Example 2, based on Example 1, proposes that in the withering step, in addition to the conditions of Example 1, an appropriate amount of antioxidant is sprayed into the withering machine, and the amount of antioxidant is controlled at 0.015 grams per kilogram of tea.

[0033] Example 3, based on Example 1, proposes that in the rolling and humidifying steps, in addition to the conditions of Example 1, an appropriate amount of natural plant extract (such as jasmine extract) is added to the rolling machine, and the amount of the extract is controlled to 0.15 grams per kilogram of tea.

[0034] In the constant temperature fermentation and microbial regulation step, in addition to the conditions of Example 1, an appropriate amount of enzyme preparation (such as amylase) is added into the fermentation chamber, and the amount of enzyme preparation is controlled at 0.0075 g per kilogram of tea.

[0035] Embodiment 4, based on Embodiment 1, proposes the following contents: In the drying and nitrogen protection steps, in addition to the conditions of Example 1, an appropriate amount of moisturizing agent (such as glycerin) is sprayed into the dryer, and the amount of moisturizing agent is controlled to 0.0035 grams per kilogram of tea leaves.

[0036] In the ultrasonic cleaning pretreatment step, in addition to the conditions of Example 1, an appropriate amount of antibacterial agent (such as sodium benzoate) is added to the cleaning solution, and the concentration of the antibacterial agent is controlled at 0.03%.

[0037] In the infrared preheating treatment step, in addition to the conditions of Example 1, the preheating temperature is also gradient controlled, and the preheating temperature is gradually increased from 36° C. to 40° C., and the preheating time is 15 minutes.

[0038] In the circulating filtration and gas purification step, in addition to the conditions of Example 1, the filtered gas is also sterilized, the sterilization temperature is controlled at 75° C., and the sterilization time is 6 minutes.

[0039] In the vacuum packaging and gas replacement steps, in addition to the conditions of Example 1, the packaging material is pretreated, and the pretreatment includes coating a layer of air-permeable but water-impermeable coating on the surface of the packaging material.

[0040] Waste generated during the processing (such as tea leaves, waste water, and waste gas) is recycled and treated, and converted into harmless substances or resources for reuse through biodegradation and chemical treatment.

[0041] The comparison data of four embodiments and prior art are as follows:

[0042] Compared with the prior art, the first to fourth embodiments have the following advantages: Improved tea quality: By optimizing parameters of each step and adding specific substances, the quality of tea is improved to varying degrees compared with the prior art.

[0043] Production efficiency: The production efficiency of the embodiment is not much different from that of the prior art, but the fourth embodiment may improve the production efficiency to a certain extent through preheating and sterilization.

[0044] Environmental protection: The embodiment adopts a combination of biodegradation and chemical treatment in waste treatment, which is more environmentally friendly and has a higher resource utilization rate compared to traditional treatment methods in the prior art. Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for clean fermentation of tea, characterized in that: The method comprises the following steps: a) Raw material selection: fresh, pest-free and pollution-free tea leaves are selected as raw materials, and the moisture content of the tea leaves is controlled at 68%-72%; b) Withering treatment: The tea leaves are withered at a temperature of 165-175°C for 2.5-3.5 minutes, and 0.8-1.2 cubic meters per minute of oxygen is introduced into the withering machine to reduce the enzyme activity in the tea leaves to below 45%; c) Rolling and humidification: Roll the tea leaves after withering, with a rolling force of 7-9 kg / cm2 for no less than 35 minutes, and spray 0.075-0.095 liters of water mist per kilogram of tea leaves evenly into the rolling machine during the rolling process; d) Constant temperature fermentation and microbial regulation: The rolled tea leaves are placed in a constant temperature fermentation room, the temperature in the fermentation room is controlled at 29℃-31℃, the humidity is controlled at 78%-82%, and gas containing 106.5 CFU / m3 of beneficial microorganisms is introduced into the fermentation room, and the fermentation time is not less than 50 hours; e) Drying and nitrogen protection: Dry the fermented tea leaves at a temperature of 85-95°C and a drying time of 1.2-1.8 hours to reduce the moisture content of the tea leaves to 6%-7%. During the drying process, nitrogen gas of 0.4-0.7 cubic meters per minute is introduced into the dryer. f) Ultrasonic cleaning pretreatment: before the raw material selection step a), the tea leaves are subjected to ultrasonic cleaning treatment, the ultrasonic frequency is controlled at 25-35kHz, and the cleaning time is not less than 7 minutes; g) Infrared preheating treatment: after the rolling step c) and before the constant temperature fermentation step d), the tea leaves are subjected to infrared preheating treatment, the preheating temperature is controlled at 38°C-42°C, and the preheating time is not less than 12 minutes; h) Circulation filtration and gas purification: In the constant temperature fermentation step d), the gas in the fermentation chamber is subjected to circulation filtration treatment with a filtration accuracy of not less than 0.25 microns, and an activated carbon adsorption device is used to remove odor and harmful substances in the gas; i) Vacuum packaging and gas replacement: After the drying step e), the tea leaves are vacuum packaged, the oxygen content in the package is controlled to be below 0.5%, and a nitrogen replacement device is used to replace the residual oxygen in the package with nitrogen; j) Real-time monitoring and intelligent control: Real-time monitoring and recording of each step in the processing, including temperature, humidity, time, and gas concentration parameters, and automatic adjustment of processing parameters through an intelligent control system to ensure the stability and controllability of the processing.

2. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the fixing step b), it also includes spraying a proper amount of antioxidant into the fixing machine, and the amount of antioxidant is controlled at 0.01-0.02 grams per kilogram of tea leaves to further reduce the enzyme activity in the tea leaves.

3. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the rolling and humidifying step c), a proper amount of natural plant extract is added into the rolling machine, and the amount of the extract is controlled to be 0.1-0.2 grams per kilogram of tea leaves to improve the taste and aroma of the tea leaves.

4. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the constant temperature fermentation and microbial regulation step d), it also includes adding a proper amount of enzyme preparation into the fermentation chamber, and the amount of enzyme preparation is controlled at 0.005-0.01 grams per kilogram of tea to promote the substance conversion and fermentation process in the tea.

5. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the drying and nitrogen protection step e), a proper amount of moisturizing agent is sprayed into the dryer, and the amount of moisturizing agent is controlled to be 0.002-0.005 grams per kilogram of tea leaves to maintain the moisture balance of the tea leaves during the drying process.

6. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the ultrasonic cleaning pretreatment step f), it also includes adding a proper amount of antibacterial agent to the cleaning solution, and the concentration of the antibacterial agent is controlled at 0.01%-0.05% to kill microorganisms on the surface of the tea leaves.

7. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the infrared preheating treatment step g), the preheating temperature is also included in a gradient control, the preheating temperature is gradually increased from 36° C. to 40° C., and the preheating time is not less than 15 minutes, so as to better meet the preheating requirements of the tea leaves.

8. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the circulating filtration and gas purification step h), the filtered gas is also sterilized, the sterilization temperature is controlled at 70° C.-80° C., and the sterilization time is not less than 5 minutes to kill microorganisms in the gas.

9. The method for clean fermentation of tea leaves according to claim 1, characterized in that: In the vacuum packaging and gas replacement step i), the packaging material is also pre-treated, and the pre-treatment includes coating a layer of air-permeable but water-impermeable coating on the surface of the packaging material to improve the sealing and preservation effect of the packaging.

10. The method for clean fermentation of tea leaves according to claim 1, characterized in that: It also includes the recycling and treatment of waste generated during the processing, including tea leaves, waste water, and waste gas, which are converted into harmless substances or resources for reuse through biodegradation, chemical treatment or physical separation.

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