阅读说明：本技术 以茶毫为原料提取茶多酚的方法 (Method for extracting tea polyphenol by taking tea hair as raw material ) 是由 谢雁 谢桂英 于 2019-11-17 设计创作，主要内容包括：本发明公开了一种以茶毫为原料提取茶多酚的方法,经过超声波浸提、乙醇提取、超滤、浓缩、萃取、提纯、干燥的步骤,得到茶多酚产品。本发明采用超声波浸提法进行提取,所需的时间短,避免了长时间处于高温下茶多酚被氧化,收率和产品质量都较传统方法高；可有效提高茶毫的利用价值,变废为宝,解决茶毫浪费的问题,对于茶毫的综合利用及深加工有着重要的意义。(The invention discloses a method for extracting tea polyphenol by taking tea milli as a raw material, which comprises the steps of ultrasonic extraction, ethanol extraction, ultrafiltration, concentration, extraction, purification and drying to obtain a tea polyphenol product. The invention adopts the ultrasonic extraction method for extraction, the required time is short, the tea polyphenol is prevented from being oxidized at high temperature for a long time, and the yield and the product quality are higher than those of the traditional method; the method can effectively improve the utilization value of the tea hairs, changes waste into valuable, solves the problem of tea hair waste, and has important significance for comprehensive utilization and deep processing of the tea hairs.)

1. The method for extracting the tea polyphenol by taking the tea ball as the raw material is characterized by comprising the following steps: the method comprises the following steps:

(1) ultrasonic leaching: removing impurities from the tea leaves, adding distilled water with the weight 10-20 times of that of the tea leaves, keeping the temperature at 35-40 ℃, soaking for 1-2 hours, and then performing ultrasonic extraction for 10-15 min to obtain water extract;

(2) adding an ethanol solution which is 3-8 times of the weight of the tea milli into the water extract obtained in the step (1), uniformly mixing, heating to 60-70 ℃, keeping for 20-30 min, and then carrying out reduced pressure distillation to recover ethanol to obtain an extracting solution;

(3) carrying out centrifugal filtration on the extracting solution in the step (2), taking supernatant, and carrying out ultrafiltration to obtain ultrafiltrate;

(4) concentration: putting the ultrafiltrate into a rotary evaporator for reduced pressure evaporation, and concentrating to 20-30% of the original liquid volume to obtain a tea polyphenol concentrated solution;

(5) adding chloroform into the tea polyphenol concentrated solution, stirring, separating to obtain a water layer, namely a tea polyphenol extract, recovering a reagent layer, keeping the tea polyphenol extract at 65-75 ℃, and stirring for 2-5 min;

(6) and (3) adding the tea polyphenol extract obtained in the step (5) into an ethanol solution with the volume 4-6 times that of the tea polyphenol extract, stirring for 10-20 min, centrifuging for 8-10 min under the condition of 2000-3000 r/min, taking a precipitate, and drying in vacuum until the water content is 8-10% to obtain the tea polyphenol.

2. The method for extracting tea polyphenol from dried tea as claimed in claim 1, wherein: the frequency of the ultrasonic wave in the step (1) is 20-30 KHz, and the temperature is 60-70 ℃.

3. The method for extracting tea polyphenol from dried tea as claimed in claim 1, wherein: the mass fraction of the ethanol solution in the step (2) is 70-80%.

4. The method for extracting tea polyphenol from dried tea as claimed in claim 1, wherein: and (4) the rotation speed of the centrifugal filtration in the step (3) is 4000-5000 r/min.

5. The method for extracting tea polyphenol from dried tea as claimed in claim 1, wherein: the parameters of the rotary evaporator in the step (4) are that the vacuum degree is 0.07-0.08 MPa, and the temperature is 45-55 ℃.

6. The method for extracting tea polyphenol from dried tea as claimed in claim 1, wherein: and (4) the mass fraction of the ethanol solution in the step (6) is 80-95%.

7. The method for extracting tea polyphenol from dried tea as claimed in claim 1, wherein: and (6) performing vacuum drying at the vacuum degree of 0.07-0.09 MPa and the temperature of 40-50 ℃.

8. The method for extracting tea polyphenol from dried tea as claimed in any one of claims 1 to 7, wherein the method comprises the following steps: the tea milli is the tea milli dropped from the tea blank in the processing process of the jasmine tea.

9. The method for extracting tea polyphenol from dried tea as claimed in any one of claims 1 to 7, wherein the method comprises the following steps: the tea milli is the tea milli fallen from the pekoe.

Technical Field

The invention relates to the technical field of tea ball processing, in particular to a method for extracting tea polyphenol by taking tea balls as raw materials.

Background

Tea polyphenols (Green Tea PolyphenolsAbbreviated as GTP), also called antioxidant, vitamin polyphenol and Fanghailing, is a compound of polyhydroxy phenolic compounds in tea. Tea polyphenols are the general name of polyphenols in tea, and are white amorphous powder, which are easily soluble in water, soluble in ethanol, methanol, acetone, ethyl acetate, and insoluble in chloroform. The tea polyphenol comprises four main chemical components of catechin, flavonoid, anthocyanin and phenolic acid, wherein the content of catechin is the highest and accounts for 60-80% of the tea polyphenol. The tea polyphenols have various physiological activities of resisting oxidation, preventing radiation, resisting aging, reducing blood lipid, reducing blood sugar, inhibiting bacteria and inhibiting enzyme, etc. Tea polyphenols is a natural antioxidant, has remarkable antioxidant effect, and can eliminate in vivo productionExcessive free radicals are generated, the structure of cell membranes is protected, the aging of the human body is slowed down, and the life of the human body is prolonged. The tea polyphenols have unique protective and therapeutic effects on skin, and can effectively prevent skin injury caused by ultraviolet, and also has antiaging, wrinkle removing, speckle removing, acne preventing, edema preventing and antiallergic effects. In addition, tea polyphenols also have effects of improving chronic renal failure and glomerulonephritis, and regulating immunity.

Theaceae of tea tree (tea tree)Theaceae) Camellia genus (A)CamelliaL．) Perennial evergreen plants originate from southwest regions of China and have a cultivation history of more than 3000 years to date. With the evolution of natural selection of tea trees, the morphological characteristics of the tea trees are changed, and the tea milli is a product of long-term evolution. Tea leaves are fine villi on the tea leaf bud tips, also called tea leaves, and contain rich theanine, tea polyphenol and other nutrient substances, and the index is an important index of tea leaf tenderness in many cases. Generally, the more tender a fresh leaf is, the more tea leaves are. Tea is common to many teas, especially green tea and black tea, such as Maojian tea. The description of the tea hair in the Chinese tea dictionary is as follows: single cell coverings with shoots and leaves projecting outward from epidermal cells on the back. The tea hair is a slender single cell, grows in the middle of basal cells and is in a round slender scroll shape. The tea ball contains rich chemical components and complete enzyme system, and can secrete aromatic substances with fragrance. Researches show that the tea hair is rich in crude fiber substances, the content of the crude fiber of the tea hair is 3-4 times of that of a tea body, and the tea hair also contains rich amino acid and other effective components such as tea polyphenol, caffeine and the like.

Guangxi scented tea mainly comprises jasmine produced in Guangxi horizontal county, which is the largest jasmine peanut production base in China and is named as 'the county of China jasmine' by the national forestry administration and the China floriculture Association. The biggest purpose of the jasmine is to produce jasmine tea. Jasmine tea is one of ten famous tea in China, not only keeps the bitter, sweet and cool effects of tea, but also has various medical health-care effects because the jasmine tea is baked to be warm tea in the processing process, can remove stomach discomfort, integrates the tea and flower fragrance health care into a whole, and is popular with people.

In the process of preparing the jasmine tea, green tea is generally adopted as a tea blank, a small number of green tea is adopted, and a lot of fluff falls off in the processing process of the green tea through the steps of rolling, spreading and drying in the air and the like, namely tea hair. Therefore, a plurality of tea hairs are also generated in the processing process of the jasmine tea. Many tea processing enterprises directly treat the tea milli as waste, and a few tea processing enterprises use the tea milli as fertilizer, which is a great waste for the tea milli. Therefore, the comprehensive utilization of the tea hairs can change waste into valuable, can promote the development of the tea industry, and has good development prospect.

Disclosure of Invention

The invention aims to provide a method for extracting tea polyphenol by taking tea milli as a raw material, which obtains a tea polyphenol product through the steps of ultrasonic extraction, ethanol extraction, ultrafiltration, concentration, extraction, purification and drying. The method has short time, and the yield and the product quality are higher than those of the traditional method; the method can effectively improve the utilization value of the tea hairs, changes waste into valuable, solves the problem of tea hair waste, and has important significance for comprehensive utilization and deep processing of the tea hairs.

The invention is realized by the following technical scheme:

the method for extracting the tea polyphenol by taking the tea milli as the raw material comprises the following steps:

(1) ultrasonic leaching: removing impurities from the tea leaves, adding distilled water with the weight 10-20 times of that of the tea leaves, keeping the temperature at 35-40 ℃, soaking for 1-2 hours, and then performing ultrasonic extraction for 10-15 min to obtain water extract;

(2) adding an ethanol solution which is 3-8 times of the weight of the tea milli into the water extract obtained in the step (1), uniformly mixing, heating to 60-70 ℃, keeping for 20-30 min, and then carrying out reduced pressure distillation to recover ethanol to obtain an extracting solution;

(3) carrying out centrifugal filtration on the extracting solution in the step (2), taking supernatant, and carrying out ultrafiltration to obtain ultrafiltrate;

(4) concentration: putting the ultrafiltrate into a rotary evaporator for reduced pressure evaporation, and concentrating to 20-30% of the original liquid volume to obtain a tea polyphenol concentrated solution;

(5) adding chloroform into the tea polyphenol concentrated solution, stirring, separating to obtain a water layer, namely a tea polyphenol extract, recovering a reagent layer, keeping the tea polyphenol extract at 65-75 ℃, and stirring for 2-5 min; chloroform is added for extraction, so that organic impurities such as caffeine in the tea hairs can be effectively removed;

(6) and (3) adding the tea polyphenol extract obtained in the step (5) into an ethanol solution with the volume 4-6 times that of the tea polyphenol extract, stirring for 10-20 min, centrifuging for 8-10 min under the condition of 2000-3000 r/min, taking a precipitate, and drying in vacuum until the water content is 8-10% to obtain the tea polyphenol.

Specifically, the frequency of the ultrasonic wave in the step (1) is 20-30 KHz, and the temperature is 60-70 ℃.

Specifically, the mass fraction of the ethanol solution in the step (2) is 70-80%.

Specifically, the rotation speed of the centrifugal filtration in the step (3) is 4000-5000 revolutions per minute.

Specifically, the parameters of the rotary evaporator in the step (4) are that the vacuum degree is 0.07-0.08 MPa, and the temperature is 45-55 ℃.

Specifically, the mass fraction of the ethanol solution in the step (6) is 80-95%.

Specifically, the vacuum degree of the vacuum drying in the step (6) is 0.07-0.09 MPa, and the temperature is 40-50 ℃.

Specifically, the tea milli is the tea milli dropped from a tea blank in the processing process of the jasmine tea.

The tea milli can also be tea milli fallen from pekoe.

The invention adopts an ultrasonic extraction method for extraction, and utilizes the mechanical crushing and cavitation of ultrasonic waves to accelerate the diffusion rate of tea polyphenol from tea hairs to a solvent, thereby greatly shortening the extraction time. The traditional process has long extraction time, and the tea polyphenol is easy to oxidize under the condition of high humidity, so that the quality is reduced, and the yield is reduced; the ultrasonic extraction of the invention needs short time, avoids the oxidation of tea polyphenol under high temperature for a long time, and has higher yield and product quality than the traditional method.

The invention has the beneficial effects that:

1. the invention adopts an ultrasonic extraction method for extraction, and utilizes the mechanical crushing and cavitation of ultrasonic waves to accelerate the diffusion rate of tea polyphenol from tea hairs to a solvent, thereby greatly shortening the extraction time. The traditional process has long extraction time, and the tea polyphenol is easy to oxidize under the condition of high humidity, so that the quality is reduced, and the yield is reduced; the ultrasonic extraction of the invention needs short time, avoids the oxidation of tea polyphenol under high temperature for a long time, and has higher yield and product quality than the traditional method.

2. The method for extracting the tea polyphenol by taking the tea hairs as the raw materials has the advantages of higher purity of the extracted tea polyphenol, low cost of the raw materials, simple operation, realization of large-scale production, effective improvement of the utilization value of the tea hairs, waste recycling, solution of the problem that the tea hairs are wasted and cannot be fully utilized, and important significance for comprehensive utilization and deep processing of the tea hairs.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the following describes the technical solutions of the present invention clearly and completely in combination with the embodiments of the present invention.