阅读说明：本技术 一种速溶藏茶粉及其制备方法 (Instant Tibetan tea powder and preparation method thereof ) 是由 何春雷 杨凯辉 郑璐 罗兴禹 毛德芝 李芬 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种速溶藏茶粉的制备方法,包括以下步骤：绿毛茶加入沸水中处理25-35min,得浸提液；使用柠檬酸和氢氧化钾调节浸提液的pH值为7.5-9,然后向浸提液底部通入臭氧,并于60-70℃条件下转化8-12h；将转化后的溶液进行喷雾干燥,制得。本发明中的制备方法可有效解决现有的制备方法存在的工艺繁琐、耗时长等问题。(The invention discloses a preparation method of instant Tibetan tea powder, which comprises the following steps: adding green tea into boiling water, and treating for 25-35min to obtain leaching solution; regulating pH value of the leaching solution to 7.5-9 with citric acid and potassium hydroxide, introducing ozone into the bottom of the leaching solution, and converting at 60-70 deg.C for 8-12 hr; and (4) carrying out spray drying on the converted solution to obtain the catalyst. The preparation method can effectively solve the problems of complex process, long time consumption and the like of the existing preparation method.)

1. The preparation method of the instant Tibetan tea powder is characterized by comprising the following steps:

(1) adding green tea into boiling water, and treating for 25-35min to obtain leaching solution;

(2) adjusting the pH value of the leaching liquor in the step (1) to 7.5-9 by using citric acid and potassium hydroxide, then introducing ozone into the bottom of the leaching liquor, and converting for 8-12h at the temperature of 60-70 ℃;

(3) and (3) carrying out spray drying on the solution converted in the step (2) to obtain the catalyst.

2. The method for preparing instant Tibetan tea powder as claimed in claim 1, wherein green raw tea of three to five leaves of a single bud is selected as the raw material in the step (1).

3. The preparation method of instant Tibetan tea powder as claimed in claim 1, wherein the mass volume ratio of the raw green tea to the boiling water in step (1) is 100g: 2-5L.

4. The method for preparing instant Tibetan tea powder as claimed in claim 1, wherein the pH in step (2) is 8.

5. The method for preparing instant Tibetan tea powder as claimed in claim 1, wherein the citric acid concentration in step (2) is 1% by mass and the potassium hydroxide concentration in step (2) is 1% by mass.

6. The method for preparing instant Tibetan tea powder as claimed in claim 1, wherein the conversion temperature in the step (2) is 65 ℃ and the conversion time is 10 hours.

7. An instant Tibetan tea powder, obtainable by the method of any one of claims 1 to 6.

Technical Field

The invention relates to the technical field of Tibetan tea powder, and particularly relates to instant Tibetan tea powder and a preparation method thereof.

Background

The Tibetan tea is generally prepared by using three to five leaves in one bud as a raw material through the basic procedures of de-enzyming, rolling, pile fermentation, drying and the like, wherein the pile fermentation is a unique procedure different from other tea types in the traditional Tibetan tea processing procedure. After the fresh leaves after the enzyme deactivation are subjected to the pile fermentation, the content substances are subjected to a series of changes, and the unique quality characteristics of the Tibetan tea are formed.

Due to the discovery of multiple health-care functions of the Tibetan tea, such as oxidation resistance, low caffeine, lipid reduction, liver protection and the like in recent years, the Tibetan tea has the health-care function and the thick cultural history, so that the Tibetan tea becomes a tea with great development potential.

The Tibetan tea is still in development and needs further improvement in the aspects of deep processing production and manufacturing process at present. Firstly, the Tibetan tea has the following problems in the aspects of traditional processing and product quality: (1) poor source management and uneven fresh leaf raw materials; (2) raw tea raw materials are lack of specifications; (3) the processing mechanism is not clear; (4) the process technology is not standard, the automatic production degree is low, and the quality management level is low. Therefore, the conventional processing method still remains to be standardized.

Secondly, the traditional Tibetan tea drinking mode is brewing and boiling, the time consumption is long, tea residues exist, and the drinking mode is very inconvenient for people in the current fast-paced life mode. The instant tea serving as a novel tea product is convenient to brew and carry, retains the original content substances in the tea, can be used for processing foods such as cakes and bread, and can be adapted to the fast-paced life of the modern society.

Thirdly, in the related reports of the processing of the existing Tibetan tea instant tea powder, the instant Tibetan tea powder is processed mostly by taking finished Tibetan tea as a raw material, while the solid-state pile fermentation is adopted in the traditional Tibetan tea processing, the process is complicated, the consumed time is long, and the parameter control difficulty is large. Meanwhile, the traditional Tibetan tea may have the possibility of pollution of the product by virus-producing fungi strains due to non-standard operation in the complicated circulation links such as pile fermentation environment, storage, transportation and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the instant Tibetan tea powder and the preparation method thereof, and the preparation method can effectively solve the problems of complicated process, long time consumption and the like of the existing preparation method.

In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows:

a preparation method of instant Tibetan tea powder comprises the following steps:

(1) adding green tea into boiling water, and treating for 25-35min to obtain leaching solution;

(2) adjusting the pH value of the leaching liquor in the step (1) to 7.5-9 by using citric acid and potassium hydroxide, then introducing ozone into the bottom of the leaching liquor, and converting for 8-12h at the temperature of 60-70 ℃;

(3) and (3) carrying out spray drying on the solution converted in the step (2) to obtain the catalyst.

According to the scheme, after green raw tea is treated in boiling water, tea cells are broken, and effective components in the tea are dissolved in water, so that subsequent conversion is facilitated; in the conversion process, the pH has great influence on the conversion rate and the conversion amount of biochemical components in the tea, and the pH is adjusted to be alkaline, so that the activity of oxidase in the tea can be improved, and the conversion effect is further improved; ozone is introduced in the conversion process, the ozone can be used as a strong oxidant to promote the oxidation of polyphenol substances in the tea, and meanwhile, the ozone can also supplement oxygen for the solution to promote the conversion; the ozone also has the bactericidal effect, can kill bacterial microorganisms in the solution, and improves the quality of the product.

Further, green tea with three to five leaves of a bud is selected as a raw material in the step (1).

Furthermore, the mass volume ratio of the green raw tea to the boiling water in the step (1) is 100g: 2-5L.

Further, the pH value in the step (2) is 8.

Further, in the step (2), the mass concentration of citric acid is 1%, and the mass concentration of potassium hydroxide is 1%.

Further, the conversion temperature in the step (2) was 65 ℃ and the conversion time was 10 hours.

The beneficial effects produced by the invention are as follows:

1. the invention adopts a liquid conversion mode to replace Tibetan tea fermentation, can improve the conversion efficiency of biochemical components, shortens the traditional fermentation time, and simultaneously adopts the liquid mode to effectively control various parameters in the conversion process, simplifies the procedure and improves the cleanliness in the conversion process.

2. The Tibetan tea powder is prepared by freeze-drying soluble components, and when the Tibetan tea powder is drunk, the Tibetan tea powder is directly added into water, the Tibetan tea powder can be quickly dissolved in the water, and no tea residue exists after the Tibetan tea powder is dissolved, so that the Tibetan tea powder has the advantage of convenience in use.

Detailed Description

Example 1

A preparation method of instant Tibetan tea powder comprises the following steps:

(1) selecting 100g of green tea with one bud of three leaves, soaking in 2.5L of boiling water, and treating in boiling water bath for 30min to obtain leaching solution;

(2) transferring the leaching solution into a 3L container, adjusting the pH value of the leaching solution in the step (1) to 8 by using 1% citric acid and 1% potassium hydroxide, transferring the leaching solution into a liquid tank, placing an air outlet pipe orifice of an ozone generator at the bottom of the liquid conversion tank, introducing ozone into the bottom of the leaching solution, and converting for 10h at 65 ℃;

(3) and (3) cooling the solution converted in the step (2) to room temperature, and then carrying out spray drying on the solution to obtain the catalyst.

Example 2

A preparation method of instant Tibetan tea powder comprises the following steps:

(1) selecting 100g of green tea with one bud of three leaves, soaking in 4L of boiling water, and treating in boiling water bath for 35min to obtain leaching solution;

(2) transferring the leaching solution into a 3L container, adjusting the pH value of the leaching solution in the step (1) to 9 by using 1% citric acid and 1% potassium hydroxide, transferring the leaching solution into a liquid tank, placing an air outlet pipe orifice of an ozone generator at the bottom of the liquid tank, introducing ozone into the bottom of the leaching solution, and converting for 8h at 70 ℃;

(3) and (3) cooling the solution converted in the step (2) to room temperature, and then carrying out spray drying on the solution to obtain the catalyst.

Example 3

A preparation method of instant Tibetan tea powder comprises the following steps:

(1) selecting 100g of green tea with five leaves of a bud, soaking in 2L of boiling water, and treating in boiling water bath for 35min to obtain leaching solution;

(2) transferring the leaching solution into a 3L container, adjusting the pH value of the leaching solution in the step (1) to 7.5 by using 1% citric acid and 1% potassium hydroxide, transferring the leaching solution into a liquid tank, placing an air outlet pipe opening of an ozone generator at the bottom of the liquid tank, introducing ozone into the bottom of the leaching solution, and converting for 12h at 70 ℃;

(3) and (3) cooling the solution converted in the step (2) to room temperature, and then carrying out spray drying on the solution to obtain the catalyst.

Comparative example 1

A preparation method of instant Tibetan tea powder comprises the following steps:

(1) 500g of green tea prepared from the three leaves of the bud is used as a raw material, and the fermented Tibetan tea is prepared in a small rotary fermentation machine according to the traditional Tibetan tea processing technology, wherein the fermentation temperature is 80 ℃, the water content is 20 percent, and the fermentation time is 74 hours;

(2) soaking 100g of the prepared fermented Tibetan tea in 2.5L of boiling water, and carrying out boiling water bath for 30 min;

(3) cooling the leaching liquor after boiling water bath to room temperature, and then carrying out spray drying to obtain the product.

Test examples

The ingredients in the prepared tea powders of example 1 and comparative example 1 were measured, respectively, and the specific results are shown in tables 1 to 3.

Table 1: biochemical index of instant Tibetan tea powder

As can be seen from the above table, the soluble sugar and tea polyphenol contents in comparative example 1 are the highest, respectively 8.52mg/ml tea soup and 2.84mg/ml tea soup, and the theabrownin, thearubigin/theaflavin values in example 1 are the highest, respectively 2.74mg/ml tea soup and 42.80, the soluble sugar content in example 1 is relatively low compared to comparative example 1 because the soluble sugar is more easily converted into aroma and tea pigment under liquid conditions; the amino acid content in example 1 was significantly higher than that in comparative example 1, so that the nutritional ingredients were sufficiently retained.

Table 2: amino acid component of instant Tibetan tea powder

As can be seen from the above table, the total amount of amino acids in example 1 is 22.4mg/ml tea soup, the total amount of amino acids in comparative example 1 is 3.66mg/ml tea soup, the total amount of amino acids in example 1 is significantly larger than that in comparative example 1, 13 amino acid components are detected in comparative example 1, wherein theanine, aspartic acid and alanine are mainly detected, 15 amino acid components are detected in example 1, and theanine, glutamic acid and aspartic acid are mainly detected.

Table 3: relative content of aroma substances (mg/ml) in tea powder_{Tea soup})

As can be seen from the data in the table above, 37 aroma substance components including 8 alcohols, 7 ketones, 2 esters, 7 aldehydes, 2 terpenes, 2 heterocycles (3 oxygen heterocycles and 3 nitrogen heterocycles) and 5 hydrocarbons are detected from the instant Tibetan tea powder in two different processing modes, and the aroma substances in the tea powder in the two processing modes have obvious difference in type and content.

In species, aldehydes, heterocycles and ketones are mainly used in comparative example 1, and alcohols, alkanes and ketones are mainly used in example 1; in content, the content of aldehyde substances in the comparative example 1 is the highest and reaches 0.36mg/100ml of tea soup, and the content of alcohol substances in the example 1 is the highest and reaches 2.63mg/100ml of tea soup; the tea powder obtained by the two methods has different flavor substances, so that the two tea powders have different tastes.

Randomly searching 50 experience persons who like drinking tea, respectively drinking the tea prepared from the tea powder in the example 1 and the tea prepared from the tea powder in the comparative example 1, and grading the tea in aspects of aroma, liquor color, taste, total score and the like, wherein the full score is 100, and the average score of 50 experience persons is taken as a final score, and specific results are shown in a table 4.

Table 4: instant Tibetan tea powder evaluation score result

	Fragrance	Color of soup	Taste of the product	General review
					Comparative example 1	96.6	89.6	94.1	93.3
Example 1	98.3	98.5	96.7	97.8

The data in the table show that the total evaluation score of the Tibetan tea in the embodiment 1 is highest, the Tibetan tea in the embodiment 1 is brownish red flaky powder, the powder is uniform and has no visible impurities, the liquor color is dark and bright, the aroma is old and strong, the taste is mellow, and the tea powder can be quickly dissolved in hot water.