CN109793085B

CN109793085B - Preparation method of fermented mulberry leaf tea

Info

Publication number: CN109793085B
Application number: CN201811440377.3A
Authority: CN
Inventors: 屈廷啟; 郭宏铭; 史高睿; 席祖勇; 胡艳玲; 雷诗涵; 何健新
Original assignee: Yichang Yingang Silkworm Technology Co ltd; College of Engineering Technology of Hubei University of Technology
Current assignee: Yichang Yingang Silkworm Technology Co ltd; College of Engineering Technology of Hubei University of Technology
Priority date: 2018-11-29
Filing date: 2018-11-29
Publication date: 2024-06-11
Anticipated expiration: 2038-11-29
Also published as: CN109793085A

Abstract

The invention discloses a preparation method of fermented mulberry leaf tea, which is characterized in that mulberry leaves are respectively subjected to classification, cleaning, salting, washing, vinegar steaming, washing, fermentation, leaching, twisting, medium-temperature drying and high-temperature baking to prepare the fermented mulberry leaf tea. According to the invention, the mulberry leaf tissue structure is expanded by soaking with saline water with a certain concentration, part of heavy metal ions inherent in the mulberry leaves are eluted, most oxalic acid in the mulberry leaves is eluted by vinegar steaming, the stomach hurting concern is avoided in tea drinking, and acetic acid and alkaloid are subjected to neutralization reaction in the vinegar steaming process, so that tea drinking can not fall asleep difficultly, and the problem that the existing technology can not effectively remove the green fishy smell of the mulberry leaf tea due to the inherent fishy smell removing function of the edible vinegar is solved.

Description

Preparation method of fermented mulberry leaf tea

Technical Field

The invention relates to the technical field of tea making, in particular to a preparation method of fermented mulberry leaf tea.

Background

The mulberry is largeleaf tree of Moraceae, is easy to cultivate, has long green leaf period and developed root system, and is a soil-retaining slope-protecting high-quality plant. Sang Hunshen is Bao, the history of Ben Cao gang mu and the like describes how to introduce health functions of mulberries and mulberry leaves, and Sang Shena is added to the catalogue of medicinal and edible products in 2011, the Ministry of health of the people's republic of China.

The modern analysis technology further defines bioactive substances in mulberry leaves, including alkaloid, tea polyphenol, tea polysaccharide and the like, particularly relatively abundant deoxynojirimycin is an alpha-glucosidase inhibitor, and modern medical research proves that the deoxynojirimycin has the effects of reducing blood sugar, reducing blood fat, resisting tumors and the like. However, the mulberry leaves and the like are not utilized efficiently, so that the economic benefit is not maximized, the technology is developed, the application value of the mulberry leaves is deeply excavated, the application industry chain of the mulberry leaves is expanded, the market is enriched, a healthy and delicious tea product is provided for people, and the farmers are promoted to get rich and the enterprise economic development is promoted.

For a long time, the mulberry leaf tea is prepared by adopting a method of sun-drying or shade-drying mulberry leaves, adding water and boiling or soaking soup for drinking, and has green smell, astringent and bitter taste. Mulberry tea is mainly drunk for treating diseases, and has extremely limited market.

Over the last decade, research articles of mulberry leaf tea preparation have been published on various publication platforms, and patent technologies have also emerged, which are considered to be not exclusive of the following two technological approaches.

1. Traditional approaches

The general process flow is as follows: see figure 1 of the drawings accompanying the specification;

The technology is widely spread in the folk, and has the defects that the green fishy smell of the mulberry leaves cannot be effectively removed by kneading and fixation, the process parameters are lacking in the sun (stir-frying) drying process, the tea soup is astringent (tingling) and has high taste and color difference due to the fact that the tea maker feels like the tea, the quality stability is poor, the heavy metal ions and oxalic acid inherent in the mulberry leaves cannot be effectively removed, the drinking quality is poor, and the large-scale and standardized production is difficult to realize.

2. Modern approaches

The general process flow is as follows: see figure 2 of the drawings accompanying the specification;

the modern approach emphasizes the control of process parameters and strengthens the stability of quality, but the problem of the green fishy smell of the mulberry leaf tea still cannot be solved because the process still inherits the traditional mode, and the inoculation fermentation improves the green fishy smell of the mulberry leaf, but the inherent matter structure problem is not fundamentally solved, the green fishy smell is weakened, the slightly fermented green fishy smell is still obvious, the fiber tissue of the mulberry leaf is rotten, the tea is not molded due to the deep fermentation, the appearance of the tea and the clarity of tea soup are affected, and the drinking quality is poor.

Still other approaches are to compound mulberry leaves with traditional black tea, which basically covers the problems of green fishy smell and the like of mulberry leaf tea, but the mulberry leaf tea is not pure mulberry leaf tea, so the discussion is omitted.

Therefore, how to provide a preparation method of mulberry leaf tea with good taste and no fishy smell is a technical problem to be solved by the technicians in the field.

Disclosure of Invention

In view of the above, the invention systematically analyzes the research results and the production process of the existing mulberry leaf tea, innovates the process flow and the process method, adopts the liquid simulation culture method of the traditional Daqu and the starter in the product of the traditional Daqu in the patent CN201510230522.5, enables the fermentation to be carried out under the participation of broad-spectrum microorganisms and enzymes, accords with the inertia of the fermentation of the traditional Chinese food, and produces the tea soup which is more delicious.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

1. The invention adopts the process flow: see figure 3 of the drawings accompanying the specification;

2. The technical scheme adopted by the invention is as follows:

1. the method comprises the following steps: the seasons and the positions are respectively, namely, the mulberry leaves with similar positions of different branches in the same season are respectively stored after the main stems are cut off, and the next procedure is carried out.

The grading method comprises the following steps: the obtained mulberry leaves are respectively classified and stored in different grades according to the size of the leaves and the color difference, and the next procedure is carried out.

Respectively and grading principles: mulberry, sprouting in spring, maturing in summer and withering in autumn, wherein Sang Shewei in autumn is particularly expensive, and the reason is long photosynthesis and long biochemical reaction, so that abundant bioactive functional components such as alkaloid, tea polyphenol, vitamin, deoxynojirimycin and the like are synthesized and accumulated in the mulberry leaves, but the mulberry leaves have different positions on branches, and have great differences in quality, physical chemistry and biochemical properties, so that the mulberry leaves are treated respectively.

2. Cleaning: the mulberry leaves are placed in a water tank with tangential flow and an overflow port, tap water is introduced, sang Shesui flows of the tangential tap water are moved in the water, and the blades are rubbed with each other, so that the washing is completed within 3-5 min.

Cleaning principle: the natural ash and even insects and bird droppings are stored on the mulberry leaves, and the mulberry leaves are purified by washing.

3. Salting: pouring a proper amount of tap water into a dipping tank, measuring the volume, accurately weighing edible salt according to the concentration of 6% (w/v), taking a proper amount of water and edible salt in the dipping tank to dissolve the salt by co-heating, pouring the dissolved salt into the dipping tank, and stirring to uniformly mix the salt with water in the tank. Taking the mulberry leaves of the same grade after classification, putting the mulberry leaves into salt water, lightly turning the mulberry leaves to ensure that the mulberry leaves are fully contacted with the salt water for about 14-18 min (the thickness of the mulberry leaves is longer and the thickness of the mulberry leaves can be shorter depending on the thickness of the mulberry leaves during classification), taking the mulberry leaves out, and transferring the mulberry leaves into a cleaning pool for cleaning.

Salting principle: the mulberry roots are planted in soil, heavy metal ions are accumulated in the mulberry leaves in the growth process, salt exists in water in the form of Cl ^- and Na ⁺ which are active in chemical property under the hydrolysis state, so that the water solution has high osmotic pressure, the mulberry leaves are permeated into the water solution in the salting process, and the heavy metal ions in the mulberry leaves undergo displacement reaction, so that the effect of eluting the heavy metal ions is achieved, and experiments prove that the mulberry leaves are soaked in 6% saline solution for 15min, and the effect of eluting the heavy metal ions is good. Meanwhile, the higher osmotic pressure enables salt water to enter the inside of the mulberry leaf tissue and even damage the mulberry leaf cells, weakens the tissue structural strength and the cell wall structural strength of the mulberry leaf, enables the effective bioactive components in the mulberry leaf to be released into the tea soup more easily when the mulberry leaf is brewed with hot water, and enables the tea soup to be plump in taste and rich in nutrition. In addition, the salted salt also has the function of inhibiting the green fishy smell.

4. Washing: taking a proper sieve, placing the sieve on a brine pond, taking out the mulberry leaves immersed by the brine, placing the mulberry leaves into the sieve, and leaching out the entrained brine. Then the mulberry leaves are poured into a clean water tank with an overflow port, tap water is added for cleaning, and the mulberry leaves are turned over until no obvious salty taste exists in the water body.

The washing principle: the salt has high osmotic pressure and corrosiveness, and the long-time contact with the mulberry leaves can seriously damage the tissue structure of the mulberry leaves, damage the integrity of the leaves and be washed away in time.

5. Steaming vinegar: the edible vinegar is prepared into 1-2% concentration by purified water in advance, poured into the bottom of a steamer, the liquid surface of the steamer is 10-15 cm according to a partition grate, the steamer is covered and heated until the edible vinegar water solution boils, the cover is uncovered, the mulberry leaves obtained in the previous step are lightly placed on the partition grate, the thickness of the mulberry leaves is evenly spread, the cover is covered for continuous heating, the cover is uncovered for about 4-5 min, and the mulberry leaves are quickly transferred into a washing tank for washing.

The vinegar steaming principle: the edible vinegar is an indispensable seasoning and is also a good organic solvent, the property of the edible vinegar is particularly active under the vaporization condition, and after the vaporized edible vinegar is contacted with mulberry leaves, acetic acid can enter the inside of mulberry leaf tissues under the combined action of heat and pressure, and according to the principle of similar compatibility, the acetic acid can be transferred with oxalic acid in the mulberry leaves in a phase-to-phase manner, so that the oxalic acid is eluted, and gastrointestinal discomfort of drinkers is avoided. The vaporized edible vinegar has good penetrability, can penetrate through fibrous tissue of mulberry leaves more easily under the action of heat, softens leaves of the mulberry leaves, and is convenient for subsequent rolling operation. In the vinegar steaming process, part of the edible vinegar can remain in the mulberry leaves, so that the mulberry leaves are more comfortable and plump in taste, and experiments prove that the vinegar steaming mulberry leaves have obvious effects for about 5 minutes, so that the vinegar steaming time is strictly controlled, and the loss of active components and vitamin is avoided.

1. Washing: quickly transferring the mulberry leaves steamed in the step 5 into a washing tank, and repeating the operation of the step 4 to wash the mulberry leaves;

the washing principle: the same washing principle as in step 4.

7. Fermentation: weighing mulberry leaves sent from the previous step, placing the mulberry leaves in a fermentation cylinder with a cover until the mulberry leaves are full, weighing 0.2% -0.5% of special distiller's yeast according to the weight of the mulberry leaves, placing the special distiller's yeast in a sterilized triangular flask, adding sugar water accounting for 200% -230 times of the weight of the distiller's yeast, stirring, uniformly sprinkling the mulberry leaves on the surface when the sugar industry is turbid and the liquid surface has bubbles, slightly pressing, covering a layer of wet flax cloth on the mulberry leaves, covering a cylinder cover, adjusting the indoor temperature to 21-25 ℃, and fermenting for 3-5 hours. Note that: and the indoor temperature is strictly controlled, the fermentation time is strictly controlled, and rotten leaves in the fermentation process are avoided.

Fermentation principle: fermentation is a process of biochemically changing biological substances in mulberry leaves by the action of enzymes and microorganisms to generate pleasant color, fragrance, taste and new functional substances. The mulberry leaf has high increase of the important functional components of deoxynojirimycin and the like after fermentation, the green fishy smell is basically removed, and the fragrance is more pleasant. The traditional fermentation is natural inoculation, and the quality is unstable due to the influence of the environment, so that the traditional reported inoculation method is often insufficient in bacterial spectrum width, and the taste of the fermented mulberry leaves is relatively monotonous. The invention adopts the liquid state simulation culture method of the traditional Daqu of patent CN201510230522.5 and the distiller's yeast prepared in the product thereof as the starter, and the distiller's yeast inherits the broad spectrum of fermenting microorganisms, simultaneously ensures the stability and has good effect.

The preparation process of the patent CN201510230522.5 distiller's yeast is as follows:

(1) Putting the whole yeast (or properly crushed) into a yeast crusher, adding 10 times of warm water with the weight of 30 ℃, preserving heat, fully absorbing water by the yeast, observing after 10 hours, if the yeast can be crushed by hands and the draft is uniform, starting a stirrer to stir and crush the yeast into suspension, sampling and detecting, and enabling 95% of 100ML sample to pass through a 40-mesh sieve, wherein the crushing is finished. Filtering with 40 mesh sieve, collecting filtrate as seed source, and treating the residue.

(2) The formula of the raw materials comprises: 70% of barley and 30% of peas.

(3) Gelatinization

The raw materials are fully crushed, pass through a 120-mesh sieve, weighed, introduced into a jacketed kettle, added with 10 times of water for gelatinization, and quickly transferred into a ventilation culture tank for cooling after gelatinization is stopped when gelatinized mash and iodine do not react in blue, and inoculated with a liquid seed source until the temperature is 28 ℃, wherein the inoculation amount is 30% of the volume of gelatinized mash, the temperature is kept at 28 ℃, and the mixture is fully stirred, ventilated and oxygenized, and cultured for 24 hours.

(4) Culturing

Under the condition of continuous stirring, the temperature of the culture solution is regulated to 35 ℃, stirring, ventilation and oxygen supply are carried out, and the culture is carried out for 24 hours at the temperature of 35 ℃;

under the condition of continuous stirring, the temperature of the culture solution is regulated to 37 ℃, stirring, ventilation and oxygen supply are carried out, and the culture is carried out for 50 hours at the temperature of 37 ℃;

Under the condition of continuous stirring, the temperature of the culture solution is regulated to 39 ℃, stirring, ventilation and oxygen supply are carried out, and the culture is carried out for 24 hours at the temperature of 39 ℃;

The total bacteria count can be stopped when the total bacteria count is more than or equal to 2.5 hundred million/ml, otherwise, the culture time is prolonged.

The temperature of the culture solution is regulated to 42 ℃ under the condition of continuous stirring, the culture solution is stirred, ventilated to oxygen, and incubated at 42 ℃ for 24 hours.

(5) Filtration and embedding

The mash after liquid culture was cross-flow filtered through a 2um microporous membrane. And collecting filtrate, and treating filter residues.

(6) Dewatering

Filtering the filtrate by a reverse osmosis membrane to remove water until the water content is less than or equal to 80%.

(7) Embedding

Adding 5% dextrin into the bacterial liquid for embedding.

(8) Spray granulation was completed in a spray dryer.

(9) Detection of

And detecting the project index according to a method specified by the relevant standard.

(10) Adjustment of

If the detection result deviates from the specified index of the product, the dosage of the embedding agent can be adjusted to meet the index requirement.

(11) And (5) vacuum packaging.

8. Leaching: and (3) dispersing Sang Shedou after fermentation, placing on a vibrating screen for uniform spreading, wherein the thickness is about 13-16cm, starting a vibrating device, starting a purified water spraying device for leaching, and manually stirring the mulberry leaves continuously during the leaching until the leached water is clear and odorless. Turning off the spraying device, continuing vibrating until the water is drained, and transferring to the next working procedure.

The principle of leaching: the surface of the fermented mulberry leaves can remain putrefactive smell generated by fermentation, and the putrefactive smell can be removed from the surface of the fermented mulberry leaves, and the putrefactive smell and the putrefactive residue of the mulberry leaves in the fermentation process can be removed.

9. Twisting: after the mulberry leaves leached in the previous step are drained, cutting the mulberry leaves into leaves with the length of 2-3cm respectively by using a cutting machine, putting the leaves into a rolling machine to be rolled into spheroids with the diameter of 0.4-0.7cm, and transferring the spheroids into the next step.

Principle of rolling: the mulberry leaves are bigger and are easy to break under the dry condition, and the appearance is affected. Exposed during storage due to the excessive surface area. Is easy to absorb water and get damp, and affects the quality of the product. Meanwhile, the dry mulberry leaves have small volume capacity per unit, which is not beneficial to transportation and storage. The large mulberry She Qiege is curled into a certain shape by a specific rolling device, so that the exposed area of the mulberry is reduced, the unit volume weight of the mulberry is increased, the quality of the mulberry tea is protected, and the mulberry tea is convenient to transport and store.

10. Medium temperature drying: setting the temperature of an electric heating oven to 70-75 ℃, uniformly spreading the rolled mature mulberry leaves on a partition grate of the oven, closing the oven door, opening a ventilation device, opening a power supply, starting drying, turning the mulberry leaves once every 20min during baking, drying for 75-85min, drying the surface of the mulberry leaves, and crushing the mulberry leaves. The moisture content in the mulberry leaves is generally 10% or less.

Medium temperature drying principle: the drying is a process of removing water, and the wet mulberry leaves are heated at high temperature for a long time, wherein free water is vaporized and volatilized, so that aroma substances and functional components of the mulberry leaves can be taken away, vitamins in the mulberry leaves are broken, and basic fiber tissues which maintain the shape of the leaves are damaged, so that the wet mulberry leaves are required to be dried at medium temperature in the early stage of drying, the free water in the mulberry leaves can be effectively removed, and the mulberry leaves and bioactive substances thereof can be protected. Experiments prove that the drying effect is better at 70-75 ℃.

11. Baking at high temperature: after the medium-temperature drying is finished, the temperature of the electric heating oven can be adjusted to 110-115 ℃, ventilation heating is continued, the baking oven is basically finished after the ventilation opening of the oven emits faint scent, the oven door is opened, the mulberry leaves are placed in a clean room with relative humidity of about 55-65% to be moisturized and cooled, and the mulberry leaves can be stored or packaged when the temperature of the mulberry leaves is reduced to normal temperature.

Principle of high temperature baking: the moisture in the mulberry leaves is reduced to below 10% after the medium-temperature drying, free water in the mulberry leaves is basically removed, bioactive functional substances such as amino acid in the mulberry leaves are dormant, the reheating vaporization amount is small, and the mulberry leaves are baked, so that complex Maillard reaction occurs in the mulberry leaves, pleasant aroma substances can be generated, the free water in the mulberry leaves is thoroughly removed, and experiments prove that the baking effect is good at 110-115 ℃.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, the mulberry leaf tissue structure is expanded by soaking with saline water with a certain concentration, part of heavy metal ions inherent in the mulberry leaves are eluted, most oxalic acid in the mulberry leaves is eluted by vinegar steaming, the stomach hurting concern is avoided in tea drinking, and acetic acid and alkaloid are subjected to neutralization reaction in the vinegar steaming process, so that tea drinking can not fall asleep difficultly, and the problem that the existing technology can not effectively remove the green fishy smell of the mulberry leaf tea due to the inherent fishy smell removing function of the edible vinegar is solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a process flow diagram of a conventional process for preparing mulberry leaf tea;

FIG. 2 is a process flow diagram of a modern route for preparing mulberry leaf tea;

FIG. 3 is a process flow diagram of the preparation of mulberry leaf tea according to the present invention.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention discloses a preparation method of fermented mulberry leaf tea, which comprises the following steps: see figure 3 of the drawings accompanying the specification;

the distiller's yeast adopted in the embodiment is a liquid simulation culture method of traditional Daqu and the distiller's yeast prepared in the product thereof in patent CN201510230522.5, and the distiller's yeast inherits fermented microorganism broad spectrum property, and simultaneously ensures the stability and good effect.

Further, in the invention, the mulberry leaf fermented tea: in particular to mulberry leaves which are prepared by taking mulberry leaves as raw materials through a series of technical processes such as microbial fermentation and the like and meet certain standards and can be directly drunk after being soaked in hot water.

Salting: the salt is prepared into a certain concentration, the osmotic pressure of water is increased, the salt enters the inside of the mulberry leaf tissue, the tissue structure is fluffy, and the operation of protecting active ingredients by controlling elution of bad ingredients such as heavy metals and the like in the salt.

Steaming vinegar: the edible vinegar is prepared into water solution with a certain concentration, the water solution is heated to be vaporized, and the counting process of protecting active ingredients by controlling elution of undesirable ingredients such as oxalic acid and the like in the water solution through mulberry leaves is performed.

Fermentation: adding special functional microorganism into folium Mori with certain humidity, and performing biochemical reaction under control to degrade protein in folium Mori to generate flavor amino acid, and performing color change.

Baking with hot air: and heating the dried air to a certain temperature to enable the air to pass through the mulberry leaves, and removing the moisture in the mulberry leaves in a controlled way, wherein the Maillard reaction is generated.

Examples

2. Cleaning: the mulberry leaves are placed in a water tank with tangential flow and overflow port, tap water is introduced, sang Shesui the flow of the tangential tap water is singed in the water, the blades are rubbed with each other, and the washing is completed in 3 min.

3. Salting: pouring a proper amount of tap water into a dipping tank, measuring the volume, accurately weighing edible salt according to the concentration of 6% (w/v), taking a proper amount of water and edible salt in the dipping tank to dissolve the salt by co-heating, pouring the dissolved salt into the dipping tank, and stirring to uniformly mix the salt with water in the tank. Taking the mulberry leaves of the same grade after classification, putting the mulberry leaves into salt water, lightly turning the mulberry leaves to ensure that the mulberry leaves are fully contacted with the salt water for about 14 minutes (depending on the thickness of the mulberry leaves during classification, the thickness of the mulberry leaves is longer, the thickness of the mulberry leaves can be shorter), fishing out the mulberry leaves, and transferring the mulberry leaves into a cleaning tank for cleaning.

5. Steaming vinegar: the edible vinegar is prepared into 1% concentration by purified water in advance, poured into the bottom of a steamer, the liquid surface of the steamer is 10cm away from the grate, the steamer is covered and heated until the edible vinegar water solution boils, the cover is uncovered, the mulberry leaves obtained in the previous procedure are lightly placed on the grate, the thickness is uniform, the cover is covered for continuous heating, the cover is uncovered for about 4min, and the mulberry leaves are quickly transferred into a washing pool for washing.

6. Washing: and (3) quickly transferring the mulberry leaves steamed in the step (5) into a washing tank, and repeating the operation of the step (4) to wash the mulberry leaves.

7. Fermentation: weighing folium Mori sent from the previous step, placing in a fermentation cylinder with a cover until the cylinder is full, weighing 0.2% of special distiller's yeast according to folium Mori weight, placing in a sterilized triangular flask, adding 2% of sugar water 200 times of distiller's yeast weight, stirring, standing until sugar industry is turbid, uniformly sprinkling on folium Mori surface, slightly pressing, covering a layer of wet hemp cloth, covering a cylinder cover, adjusting indoor temperature to 21deg.C, and fermenting for 3 hr. Note that: and the indoor temperature is strictly controlled, the fermentation time is strictly controlled, and rotten leaves in the fermentation process are avoided.

8. Leaching: and (3) dispersing Sang Shedou after fermentation, placing on a vibrating screen, paving uniformly, wherein the thickness is about 13cm, starting a vibrating device, starting a purified water spraying device for leaching, and manually turning over the mulberry leaves continuously during the leaching until the leached water is clear and odorless. Turning off the spraying device, continuing vibrating until the water is drained, and transferring to the next working procedure.

9. Twisting: after the mulberry leaves leached in the previous step are drained, the mulberry leaves are cut into leaves with the length and the width of 2cm by a cutting machine, and the leaves are placed in a rolling machine to be rolled into spheroids with the diameter of 0.4cm, and the mulberry leaves are transferred to the next step.

10. Medium temperature drying: setting the temperature of an electric heating oven at 70 ℃, uniformly spreading the rolled and ripe mulberry leaves on a partition grate of the oven, closing the oven door, opening a ventilation device, turning on a power supply, starting drying, turning the mulberry leaves once every 20min during the baking period, drying for 75min, drying the surface of the mulberry leaves, and crushing the mulberry leaves by kneading. The moisture content in the mulberry leaves is generally 10% or less.

11. Baking at high temperature: after the medium-temperature drying is finished, the temperature of the electric heating oven can be adjusted to 110 ℃, ventilation heating is continued, the baking oven is basically finished after the ventilation opening of the oven emits faint scent for 25 minutes, the oven door is opened, the mulberry leaves are placed in a clean room with the relative humidity of about 55% to be moisturized and cooled, and the mulberry leaves can be stored or packaged when the temperature of the mulberry leaves is reduced to normal temperature.

Examples

2. Cleaning: the mulberry leaves are placed in a water tank with tangential flow and overflow port, tap water is introduced, sang Shesui flows of the tangential tap water are moved in the water, and the blades are rubbed with each other for 5min to finish washing.

3. Salting: pouring a proper amount of tap water into a dipping tank, measuring the volume, accurately weighing edible salt according to the concentration of 6% (w/v), taking a proper amount of water and edible salt in the dipping tank to dissolve the salt by co-heating, pouring the dissolved salt into the dipping tank, and stirring to uniformly mix the salt with water in the tank. Taking the mulberry leaves of the same grade after classification, putting the mulberry leaves into salt water, lightly turning the mulberry leaves to ensure that the mulberry leaves are fully contacted with the salt water for about 18 minutes (depending on the thickness of the mulberry leaves during classification, the thickness of the mulberry leaves is longer, the thickness of the mulberry leaves can be shorter), fishing out the mulberry leaves, and transferring the mulberry leaves into a cleaning tank for cleaning.

5. Steaming vinegar: the edible vinegar is prepared into 2% concentration by purified water in advance, poured into the bottom of a steamer, the liquid surface of the steamer is 15cm away from the grate, the steamer is covered and heated until the edible vinegar water solution boils, the cover is uncovered, the mulberry leaves obtained in the previous procedure are lightly placed on the grate, the thickness is even, the cover is covered for continuous heating, the cover is uncovered for about 5min, and the mulberry leaves are quickly transferred into a washing pool for washing.

7. Fermentation: weighing folium Mori sent from the previous step, placing into a fermentation cylinder with a cover until the cylinder is full, weighing 0.5% of special distiller's yeast according to folium Mori weight, placing into a sterilized triangular flask, adding sugar water 230 times of distiller's yeast weight, stirring, standing until sugar industry is turbid, uniformly sprinkling on folium Mori surface, slightly pressing, covering a layer of wet hemp cloth, covering a cylinder cover, adjusting indoor temperature to 25deg.C, and fermenting for 5 hr. Note that: and the indoor temperature is strictly controlled, the fermentation time is strictly controlled, and rotten leaves in the fermentation process are avoided.

8. Leaching: and (3) dispersing Sang Shedou after fermentation, placing on a vibrating screen, paving uniformly, wherein the thickness is about 16cm, starting a vibrating device, starting a purified water spraying device for leaching, and manually turning over the mulberry leaves continuously during the leaching until the leached water is clear and odorless. Turning off the spraying device, continuing vibrating until the water is drained, and transferring to the next working procedure.

9. Twisting: after the mulberry leaves leached in the previous step are drained, the mulberry leaves are cut into leaves with the length of 3cm by a cutting machine, and the leaves are placed in a rolling machine to be rolled into spheroids with the diameter of 0.7cm, and the mulberry leaves are transferred to the next step.

10. Medium temperature drying: setting the temperature of an electric heating oven at 75 ℃, uniformly spreading the rolled and ripe mulberry leaves on a partition grate of the oven, closing the oven door, opening a ventilation device, turning on a power supply, starting drying, turning the mulberry leaves once every 20min during the baking period, drying for 85min, drying the surface of the mulberry leaves, and crushing the mulberry leaves by kneading. The moisture content in the mulberry leaves is generally 10% or less.

11. Baking at high temperature: after the medium-temperature drying is finished, the temperature of the electric heating oven can be adjusted to 115 ℃, ventilation heating is continued, the oven is subjected to ventilation opening for 35 minutes to emit faint scent, baking is basically finished, the oven door is opened, the mulberry leaves are placed in a clean room with the relative humidity of about 65% to be subjected to moisture regain and cooling, and the mulberry leaves can be stored or packaged when the temperature of the mulberry leaves is reduced to normal temperature.

Examples

2. Cleaning: the mulberry leaves are placed in a water tank with tangential flow and overflow port, tap water is introduced, sang Shesui the flow of the tangential tap water is singed in the water, the blades are rubbed with each other, and the washing is completed within 4 min.

3. Salting: pouring a proper amount of tap water into a dipping tank, measuring the volume, accurately weighing edible salt according to the concentration of 6% (w/v), taking a proper amount of water and edible salt in the dipping tank to dissolve the salt by co-heating, pouring the dissolved salt into the dipping tank, and stirring to uniformly mix the salt with water in the tank. Taking the mulberry leaves of the same grade after classification, putting the mulberry leaves into salt water, lightly turning the mulberry leaves to ensure that the mulberry leaves are fully contacted with the salt water for about 15 minutes (depending on the thickness of the mulberry leaves during classification, the thickness of the mulberry leaves is longer, the thickness of the mulberry leaves can be shorter), fishing out the mulberry leaves, and transferring the mulberry leaves into a cleaning tank for cleaning.

5. Steaming vinegar: the edible vinegar is prepared into 1% concentration by purified water in advance, poured into the bottom of a steamer, the liquid surface of the steamer is 12cm away from the grate, the cover is covered and heated until the edible vinegar water solution boils, the cover is uncovered, the mulberry leaves obtained in the previous procedure are lightly placed on the grate, the thickness is even, the cover is covered and heated continuously, the cover is uncovered for about 4min, and the mulberry leaves are quickly transferred into a washing pool for washing.

7. Fermentation: weighing folium Mori sent from the previous step, placing in a fermentation cylinder with a cover until the cylinder is full, weighing 0.2% of special distiller's yeast according to folium Mori weight, placing in a sterilized triangular flask, adding 2% of sugar water 200 times of distiller's yeast weight, stirring, standing until sugar industry is turbid, uniformly sprinkling on folium Mori surface, slightly pressing, covering a layer of wet hemp cloth, covering a cylinder cover, adjusting indoor temperature to 24deg.C, and fermenting for 4 hr. Note that: and the indoor temperature is strictly controlled, the fermentation time is strictly controlled, and rotten leaves in the fermentation process are avoided.

8. Leaching: and (3) dispersing Sang Shedou after fermentation, placing on a vibrating screen, spreading uniformly, wherein the thickness is about 15cm, starting a vibrating device, starting a purified water spraying device for leaching, and manually turning over the mulberry leaves continuously during the leaching until the leached water is clear and odorless. Turning off the spraying device, continuing vibrating until the water is drained, and transferring to the next working procedure.

9. Twisting: after the mulberry leaves leached in the previous step are drained, the mulberry leaves are cut into leaves with the length and the width of 2cm by a cutting machine, and the leaves are placed in a rolling machine to be rolled into spheroids with the diameter of 0.5cm, and the mulberry leaves are transferred to the next step.

10. Medium temperature drying: setting the temperature of an electric heating oven at 70 ℃, uniformly spreading the rolled and ripe mulberry leaves on a partition grate of the oven, closing the oven door, opening a ventilation device, turning on a power supply, starting drying, turning the mulberry leaves once every 20min during the baking period, drying for 80min, drying the surface of the mulberry leaves, and crushing the mulberry leaves by kneading. The moisture content in the mulberry leaves is generally 10% or less.

11. Baking at high temperature: after the medium-temperature drying is finished, the temperature of the electric heating oven can be adjusted to 110 ℃, ventilation heating is continued, the oven is subjected to ventilation opening for 30 minutes to emit faint scent, baking is basically finished, the oven door is opened, the mulberry leaves are placed in a clean room with the relative humidity of about 60% to be subjected to moisture regain and cooling, and the mulberry leaves can be stored or packaged when the temperature of the mulberry leaves is reduced to normal temperature.

In conclusion, the invention expands the tissue structure of mulberry leaves by dipping with saline water with a certain concentration, elutes partial heavy metal ions inherent in the mulberry leaves, elutes most oxalic acid in the mulberry leaves by vinegar steaming, avoids the worry of stomach hurting of tea drinking, and makes acetic acid and alkaloid generate neutralization reaction in the vinegar steaming process, so that tea drinking can not fall asleep, and the problem that the prior art can not effectively remove the green fishy smell of the mulberry leaf tea due to the inherent fishy smell removing function of edible vinegar is solved.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The preparation method of the fermented mulberry leaf tea is characterized by comprising the following process steps:

1) Respectively classifying the mulberry leaves;

2) Cleaning: cleaning and decontaminating the mulberry leaves treated in the step 1);

3) Salting: pouring a proper amount of tap water into a dipping tank, measuring the volume, accurately weighing edible salt according to the concentration of 6% (w/v), taking a proper amount of water and edible salt in the dipping tank to dissolve the salt by co-heating, pouring the dissolved salt into the dipping tank, stirring to uniformly mix the dissolved salt with water in the tank, taking the mulberry leaves of the same grade after grading, putting the mulberry leaves into the salt water, slightly turning the mulberry leaves into the salt water, fully contacting the mulberry leaves with the salt water, and soaking for 14-18min;

4) Washing: washing after the mulberry leaves are salted;

5) Steaming vinegar: the edible vinegar is prepared into 1 to 2 percent of concentration by purified water in advance, the mixture is poured into the bottom of a steamer, the liquid level of the steamer is 10 to 15cm according to a partition grate, the cover is covered and heated until the edible vinegar water solution boils, the cover is uncovered, the mulberry leaves washed in the step 4) are placed on the partition grate, the spreading is carried out, the cover is covered and the heating is continued, the cover is uncovered after 4 to 5 minutes, and the next procedure is carried out;

6) Washing: quickly transferring the mulberry leaves steamed by the vinegar in the step 5) into a washing tank, and repeating the operation of the step 4) to wash the mulberry leaves;

7) Fermentation: weighing mulberry leaves sent from the previous procedure, placing the mulberry leaves in a fermentation cylinder with a cover until the fermentation cylinder is full, weighing 0.2% -0.5% of distiller's yeast prepared in the embodiment of patent CN201510230522.5 according to the weight of the mulberry leaves, placing the distiller's yeast into a sterilized triangular flask as a fermenting agent, adding 2% -5% of syrup 200-230 times of the weight of the distiller's yeast, stirring, uniformly sprinkling the mixture on the surface of the mulberry leaves when the syrup is turbid and bubbles appear on the liquid surface, lightly pressing the mixture, covering a layer of wet flax cloth on the mixture, covering a cylinder cover, adjusting the indoor temperature to 21-25 ℃, and fermenting for 3-5 hours;

8) Leaching: spreading the fermentation Sang Shedou on a vibrating screen, uniformly spreading, starting a purified water spray device for leaching, continuously turning over the mulberry leaves during the leaching to uniformly leaching, turning off the spray device when the leached water is clear and odorless, continuously vibrating until the water is drained, and transferring to the next procedure;

9) Twisting: after the mulberry leaves leached in the previous step are drained, the mulberry leaves are cut into leaves with the length of 2cm to 3cm, the leaves are placed in a rolling machine to be rolled into spheres, and the next step is carried out;

10 Medium temperature drying: uniformly spreading the rolled and ripe mulberry leaves on a partition grate of a baking oven, drying at 70-75 ℃ for 75-85min, turning the mulberry leaves once every 20-25min during baking, and finishing the drying after the surface of the mulberry leaves is dry and has thorn hand feeling and the rolling and fragmentation;

11 High temperature baking: after the medium-temperature drying is finished, the temperature of the oven is adjusted to 110-130 ℃, ventilation heating is continued, the baking is finished after the ventilation opening of the oven emits faint scent, then the mulberry leaves are put into a clean environment with the relative humidity of 55-65% to make the mulberry leaves get damp again and cooled, and the mulberry leaf tea is obtained after the temperature of the mulberry leaves is reduced to the room temperature.

2. A method for preparing fermented mulberry leaf tea according to claim 1, wherein the respective methods in step 1) are: the seasons and the positions are respectively, namely, the mulberry leaves with similar positions of different branches are respectively stored after the main stems are cut off in the same season.

3. The method for preparing fermented mulberry leaf tea according to claim 1, wherein the classification method in step 1) is as follows: the finished mulberry leaves are classified into different grades according to the size of the leaves and the color difference.

4. The method for preparing fermented mulberry leaf tea according to claim 1, wherein the cleaning method in the step 2) is as follows: mulberry leaves are placed in a water tank with tangential flow and overflow port, tap water is introduced, sang Shesui the flow of the tangential tap water is singed in the water, and the leaves are rubbed with each other.

5. The method for preparing fermented mulberry leaf tea according to claim 1, wherein the washing method in the step 4) is as follows: taking a proper sieve, placing the sieve on a salt water tank, fishing out mulberry leaves immersed by salt water, placing the mulberry leaves into the sieve, leaching out the salt water, pouring the mulberry leaves into a clean water tank with an overflow port, adding tap water for cleaning, and turning over until no obvious salty taste exists in the water body.