CN112237227A

CN112237227A - Rose black tea and preparation method thereof

Info

Publication number: CN112237227A
Application number: CN202011136243.XA
Authority: CN
Inventors: 邵剑
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-07-06
Filing date: 2020-10-21
Publication date: 2021-01-19

Abstract

The application relates to the technical field of black tea processing technology, in particular to rose black tea and a preparation method thereof. The preparation method of the rose black tea comprises the following steps: s1, co-processing the rose flavor substances and the finished black tea, wherein the processing temperature is 15-25 ℃, and the processing time is 20-30 h, so as to obtain the reprocessed black tea; s2, drying the reprocessed black tea obtained in the step S1. Through the steps, the acerbity feeling of the prepared rose black tea after brewing can be reduced, and the fragrance of the rose black tea is improved, so that the drinking taste of the rose black tea is improved. The application also comprises the rose black tea prepared by the preparation method.

Description

Rose black tea and preparation method thereof

Technical Field

The application relates to the technical field of black tea processing technology, in particular to rose black tea and a preparation method of the rose black tea.

Background

The black tea is a common beverage, has excellent taste and better nutrition and health care effects, and enjoys a huge market at home and abroad. With the improvement of living standard, consumers are not satisfied with the taste of simple black tea, and different tastes are added to the black tea, wherein the rose black tea is popular with consumers due to the fragrance of the rose and the black tea which supplement each other.

Chinese patent with publication number CN109566797A and publication date of 2019, 4 and 5 discloses a preparation method of rose black tea, which comprises the steps of picking, withering, kneading tea leaves obtained in the working procedures, mixing the tea leaves with dry rose petals according to the mass ratio of 10: 0.5-1, fermenting and drying to obtain the rose tea.

In the prior art, the rose black tea is prepared by fermenting the rose or rose-flavor substance and the picked and pre-treated tea leaves together, and soaking the fragrance component in the rose or rose-flavor substance into the tea leaves in the fermentation process. However, in the above prior art, the fermentation of black tea needs to be performed under conditions of sufficient nutrition, high room temperature and high humidity, which can cause the reduction substances such as alcohol substances and ester substances in the rose or rose flavor substances to be oxidized into acid, and the prepared black tea inevitably has a certain degree of sourness, which affects the taste of the brewed black tea.

Disclosure of Invention

Aiming at the defects in the prior art, the first purpose of the application is to provide a preparation method of rose black tea, which reduces the oxidation of reducing substances in roses in the preparation process.

The second purpose of the application is to provide rose black tea which has better taste and less acerbity.

The first purpose of the application is realized by the following technical scheme: a preparation method of rose black tea comprises the following steps:

s1, co-processing the rose flavor substances and the finished black tea, wherein the processing temperature is 15-25 ℃, and the processing time is 20-30 h, so as to obtain the reprocessed black tea;

s2, drying the reprocessed black tea obtained in the step S1;

wherein the rose flavor comprises at least one of rose essential oil and rose extract.

In the present application, rose black tea is obtained by co-processing finished black tea with rose flavour. The finished black tea is obtained by fermenting tea leaves, wherein catechin, tea polyphenol and other substances are oxidized to form catechin dimers, thearubigins, theaflavin and other substances, so that the whole color of the finished black tea is darkened and reddened. In the above process, catechin and tea polyphenol produce o-quinone as an intermediate, and this step is required to be performed at a relatively high temperature.

When the black tea is fermented and roasted to obtain fuchsin tea, oxidase in the black tea is inactivated due to high temperature in the roasting process. Therefore, when the finished black tea after fermentation and stir-frying is further processed, the reducing substances in the rose flavor substances are not easy to be oxidized, and the nutrient substances in the black tea after fermentation are not easy to be further oxidized into acid, so that the acid and astringent feeling of the rose black tea generated in the processing process is reduced.

In addition, during the processing, the rose flavor substances contain carbonyl substances such as flavone and the like, and the rose flavor substances and the finished black tea both contain more amino acids, so that the materials can generate Maillard reaction during the co-processing of the black tea and the rose flavor substances, and the fragrance in the black tea is further increased. And the aroma can be preserved for a long time under the condition of lower temperature and humidity.

The present application may be further configured in a preferred example to: the rose flavor substance is rose essential oil.

In the technical scheme, the rose essential oil is viscous liquid and can be more uniformly and effectively adhered to the surface of the finished black tea in the common treatment process of the rose essential oil and the finished black tea, so that the nutrient substances in the rose essential oil can be more effectively adsorbed in the finished black tea. In addition, substances playing an important role in rose fragrance are mainly volatile liquid, and the rose essential oil can effectively preserve the fragrance substances, so that the rose fragrance is transferred to black tea as far as possible. In addition, the rose essential oil is characterized in that after the finished product black tea is jointly processed and dried, the residual quantity of solid matters is small, and the whole form of the finished product black tea is not easily influenced.

The present application may be further configured in a preferred example to: the rose essential oil is extracted by a steam distillation method.

The steam distillation method can effectively remove solid matters in the rose in the process of extracting the rose essential oil, so that the obtained rose essential oil is purer and contains less impurities, and the prepared rose black tea has better and finer mouthfeel in the brewing process.

The present application may be further configured in a preferred example to: the addition amount of the rose essential oil is 2.6-4% of the weight of the finished black tea.

In the technical scheme, the addition amount of the rose essential oil is further limited. If the addition amount of the rose essential oil is too much, more oily substances cannot be dried in the drying process, so that the obtained rose black tea is easy to be hardened into blocks, absorb water, absorb moisture and even deteriorate. If the added rose essential oil is too small, the fragrance is insufficient, and the taste and fragrance of the rose black tea are deteriorated.

The present application may be further configured in a preferred example to: the specific operation method of step S1 is as follows: placing the finished black tea in a container with holes in the side wall, spraying rose essential oil on the upper part, turning and uniformly mixing the finished black tea and the rose essential oil, then placing the container in a ventilated place and keeping out of the sun, controlling the temperature to be 15-25 ℃, and storing for 20-30 h to obtain the reprocessed black tea.

A light-shielding and ventilation mode is adopted in the common treatment process of the finished black tea and the rose essential oil, so that the temperature and the humidity in the treatment process are reduced, the fresh smell of the tea is kept, and the fragrant substances in the tea are not easy to deteriorate under the irradiation of sunlight. Meanwhile, the tea leaf tea is also helpful for keeping the color of the tea leaves. In addition, during the treatment process, the black tea is placed in a container with holes on the side wall, so that the black tea at the bottom can be fully contacted with the air, thereby inhibiting the propagation of anaerobic bacteria in the black tea and preventing the black tea from being rotten in the processing process.

The present application may be further configured in a preferred example to: the finished black tea is Keemun black tea.

Keemun black tea is selected as the raw material in this application. The Keemun black tea has low sweet taste, but strong tea taste and fragrance. The rose essential oil has strong fragrance, and if the rose essential oil is prepared into the rose black tea with other black tea, the rose fragrance in the rose essential oil covers the tea fragrance of the black tea in smell sense, and the sweet taste in the black tea changes the faint scent of the rose in taste sense, so that the tea fragrance and the faint scent of the rose cannot be fully embodied. When the rose essential oil and the Keemun black tea are prepared, the rose fragrance and the tea fragrance can be kept in smell, the faint scent of the rose can be highlighted in taste, and the taste and the fragrance are good.

The present application may be further configured in a preferred example to: after step S2 is finished, the method further includes the following steps: and S3, carrying out fragrance improvement treatment on the dried rose black tea for 1-3 times.

Through further aroma improvement, the black tea further absorbs aroma molecules in the aroma improving agent in the aroma improving process, so that the prepared rose black tea has stronger aroma. And the rose black tea is dried and then subjected to aroma raising, and in the drying process, cells on the surface of the tea are dehydrated and shrunk to form a fine void structure, so that the rose black tea is beneficial to adsorbing more aroma molecules, and the aroma of the black tea is further improved.

The present application may be further configured in a preferred example to: in the step S3, the aroma raising agent used in the aroma raising treatment process is rose petals, and the adding weight of the rose petals is 0.7-1.2% of the weight of the finished black tea.

In the technical scheme, the rose petals contain more fragrant substances, so that the addition of the rose petals in the fragrance enhancing process is beneficial to fragrance increase and is convenient for removing the rose petals from the tea leaves after fragrance enhancement.

The second purpose of the application is realized by the following technical scheme: a rose black tea produced by the process of any one of claims 1 to 8.

The rose black tea prepared by the method has the advantages of rich fragrance, basically no sour and astringent feeling after brewing, soft taste and suitability for drinking.

In summary, the present application includes at least one of the following beneficial technical effects:

in the application, the rose flavor substances and the finished black tea are jointly treated at room temperature, so that the oxidation of substances which are easily oxidized in the rose flavor substances by oxidase in the black tea is reduced in the process, and the rose black tea with mellow mouthfeel, less sour and astringent taste and full fragrance is obtained.

Detailed Description

The present application will be described in further detail with reference to examples and comparative examples.

Example 1: the preparation method of the rose black tea comprises the following specific steps:

s1, weighing 20kg of finished Qimen black tea, placing in a bamboo basket, sprinkling 600g of rose flavor substances on the finished Qimen black tea, turning over to uniformly mix the finished black tea and rose essential oil, storing for 24h in a dark and ventilated place, and controlling the temperature at 20 ℃ during storage to obtain reprocessed black tea;

s2, drying the reprocessed black tea obtained in the step S1 in a drying room at 60 ℃.

The rose flavor substance is rose essential oil, and the extraction method of the rose essential oil comprises the following steps:

grinding rose flower, adding water, and stirring to uniform, wherein the amount of water is three times of the weight of rose flower. Filtering the above materials with a 120-mesh sieve, placing in a container, heating to 95 deg.C, introducing water vapor, condensing and recovering dissipated steam, separating liquid, and collecting the lower organic phase as rose essential oil.

Examples 2 to 8: a rose black tea, differing from example 1 in the specific parameters in step S1.

Comparative examples 1 to 3: a rose black tea, differing from example 1 in the specific parameters in step S1.

Specific parameters in examples 2 to 8 and comparative examples 1 to 3 are shown in Table 1.

Table 1: examples 2 to 8 and comparative examples 1 to 3

In example 8, the rose extract was a 10: 1 rose extract from sierra bioengineering ltd.

Example 9: a rose black tea, which differs from example 1 in that the rose essential oil is obtained by an organic solvent extraction method, specifically the method comprises the following steps:

grinding rose flowers until the rose flowers are crushed, adding petroleum ether, wherein the adding amount of the petroleum ether is 10 times of the mass of the rose flowers, then fully stirring, sieving by a 120-mesh sieve, adding distilled water with the volume equal to that of the petroleum ether into the obtained filtrate, extracting, reserving an organic phase, and carrying out vacuum spin drying on the petroleum ether in the organic phase to obtain the rose essential oil.

Example 10: a rose black tea, which differs from example 1 in that step S1 is specifically as follows: weighing 20kg of Qimen black tea, placing in bamboo basket, sprinkling 600g of rose essential oil on the Qimen black tea, turning to mix the black tea and the rose essential oil, treating under outdoor illumination for 24 hr, and controlling temperature at 20 deg.C to obtain the treated black tea.

Example 11: a rose black tea, which differs from example 1 in that step S1 is specifically as follows: weighing 20kg of Qimen black tea, placing in bamboo basket, sprinkling 600g of rose essential oil on the Qimen black tea, turning to mix the black tea and the rose essential oil, and processing in a closed room in dark place for 24 hr at 20 deg.C to obtain reprocessed black tea.

Example 12: a rose black tea, which differs from example 1 in that step S1 is specifically as follows: weighing 20kg of Keemun black tea, placing in a stainless steel barrel with no hole on side wall and bottom surface, sprinkling 600g of oleum Rosae Rugosae on Keemun black tea, turning to mix the black tea and oleum Rosae Rugosae, and processing in dark and ventilated place for 24h at 20 deg.C to obtain reprocessed black tea.

Example 13: a rose black tea, which is different from example 1 in that it further comprises step S3: and after drying, adding a fragrance extracting agent into the rose black tea, and performing fragrance extraction treatment in a fragrance extracting machine. The fragrance extracting agent is 140g of rose petals.

Example 14: a rose black tea, which is different from example 13 in that 240g of rose petals is used as an aroma raising agent in step S3.

Example 15: a rose black tea, which is different from example 13 in that in step S3, the aroma raising agent is 200g of whole rose flowers.

Example 16: a rose black tea, differing from example 13 in that in step S3, the aroma raising agent was 200g of 10: 1 rose extract.

Comparative example 4: a rose black tea is prepared by the following steps: withering and rolling fresh keemun black tea leaves, adding dried roses, uniformly stirring, and treating for 3-4 h at the temperature of 26-28 ℃ and the relative humidity of more than 90%. And then frying and enhancing the aroma of the processed tea leaves.

The following experimental tests were carried out for examples 1 to 16 and comparative examples 1 to 4:

experiment 1, determination of citronellol content: taking 5g of the prepared rose black tea sample, grinding and crushing, adding 10ml of ethanol, fully mixing, carrying out ultrasonic treatment for 2min, sieving with a 120-mesh sieve, taking clear liquid, and determining according to the determination method of the content of citronellol in GB/T24800.10-2009.

Experiment 2, determination of geraniol content: taking a 5g prepared rose black tea sample, grinding and crushing, adding 10ml of ethanol, carrying out ultrasonic treatment for 2min after fully mixing, sieving with a 120-mesh sieve, taking clear liquid, measuring by liquid chromatography, and comparing with a standard curve to obtain the geraniol content in the rose black tea sample.

Experiment 3, determination of phenethyl alcohol content: taking 5g of the prepared rose black tea sample, grinding and crushing, adding 10ml of ethanol, fully mixing, carrying out ultrasonic treatment for 2min, sieving with a 120-mesh sieve, taking clear liquid, measuring by liquid chromatography, and comparing with a standard curve to obtain the content of phenethyl alcohol in the rose black tea sample.

Experiment 4, taste scoring of black tea, 5g samples of rose black tea for each group of examples and comparative examples, each brewed with 300mL of purified water at 90 ℃, and 10 volunteers were asked to taste the black tea brewed for each group of examples and comparative examples, and the scores were made according to the criteria of table 2.

Table 2: EXAMPLES AND COMPARATIVE EXAMPLES Black tea Scoring Standard

The tests of experiments 1 to 4 were carried out for examples 1 to 5 and comparative examples 1 to 4, and the test results are shown in Table 3.

Table 3: comparison of Experimental data for examples 1-5 and comparative examples 1-4

Compared with examples 1-5 and comparative example 4, the content of citronellol, geraniol and phenethyl alcohol in the rose black tea prepared by the preparation method is higher, the fragrance before and after brewing is stronger, the taste is less sour and astringent, and the drinking taste is better. The theory is presumed that when the rose black tea in the embodiments 1 to 5 is prepared, the rose and the finished black tea are processed together, and oxidase in the frying process of the finished black tea is inactivated, so that the phenomenon that alcohol substances such as citronellol and geraniol in the rose are oxidized into acid by the oxidase in the black tea is reduced, and the prepared rose black tea has more sufficient fragrance, less sour and astringent feeling in drinking and better taste.

Examples 2 to 5 adjust the amount of added rose essential oil based on example 1, wherein the differences between example 2 and example 3 and example 1 are small, and example 4 is that too much rose essential oil is added, so that the overall separation degree of the processed black tea is poor, the black tea is easy to harden, the leaves of the black tea are easy to break during brewing, and the purity of the tea water after brewing the rose black tea is poor. In example 5, the rose essential oil was added in an excessively small amount, which resulted in the production of a rose black tea having a poor flavor.

Comparing comparative examples 1 to 3 with example 1, it is understood that in comparative example 1, the treatment time is long, and the reducing substances such as citronellol and geraniol in the rose extract are oxidized into acid, which leads to sour taste. Comparative example 2 the treatment time was short and the finished black tea could not sufficiently absorb the aroma components in the rose extract, resulting in lower geraniol and citronellol content and poorer aroma score in the prepared rose black tea. In comparative example 3, the temperature was high during the treatment, which resulted in decomposition or oxidation of the flavor components in the rose essential oil during the co-treatment of the finished black tea and the rose essential oil, resulting in insufficient flavor of the rose black tea and a certain degree of sourness and astringency.

Data pairs for experiments 1 to 4 for the rose black teas prepared in examples 6 to 12 and example 1 are shown in Table 4.

Table 4: comparison of data for examples 6-12 with example 1

By comparing example 1 with examples 6 and 7, it was demonstrated that rose black tea prepared using keemun black tea had both better aroma and mouthfeel after infusion compared to yunnan and nordic species. In example 8, the rose extract was used in a ratio of 10: 1 instead of the rose essential oil, the rose extract was in the form of powder, a small amount of the rose extract was added to dissolve and adhere to the surface of tea leaves, and the tea leaves were difficult to absorb the fragrant substances such as citronellol and geraniol, resulting in poor fragrance of the actual rose black tea and the actual black tea. In addition, the rose extract had a high content of phenethyl alcohol, which is presumed to be due to roses. In example 9, the rose essential oil was obtained by a solvent extraction method, and the extracted rose essential oil was insufficient in purity and contained a small amount of solid impurities, resulting in poor taste and poor purity of the tea water of the brewed rose black tea.

Examples 10 to 12 the treatment process of rose black tea was adjusted compared to example 1. In example 10, the processing of the rose black tea is performed under outdoor illumination, and ultraviolet rays in sunlight can easily promote oxidation of the rose flavor substances and the reductive components in the finished black tea, so that the fragrance of the rose black tea is insufficient. In example 11, the temperature and time of the processing were finely adjusted, and the influence on the taste of the rose black tea was small. In example 12, the rose tea was treated in a non-porous container, and the rose tea had poor aroma and a remarkable sour and astringent taste after infusion, and it is presumed that the bottom tea leaves were anoxic during the processing, resulting in the growth of anaerobic bacteria, and thus the tea water after infusion was sour, and had poor aroma and purity, although the prepared rose black tea contained a lot of aroma substances such as citronellol and geraniol.

Data pairs of experiments 1 to 4 for the rose black tea prepared in examples 13 to 16 and example 1 are shown in Table 5.

Table 5: comparison of data for examples 13-16 with example 1

Examples 13 to 16 have an additional flavor-enhancing treatment step after step S2, compared to example 1. It can be seen from comparison between example 1 and examples 13 to 16 that the flavor of tea leaves before brewing and the flavor of tea water after brewing can be effectively improved regardless of the selection of any flavor enhancer. However, different fragrance enhancing agents have certain differences, for example, when rose petals are used as the fragrance enhancing agent, the fragrance enhancing effect is stronger than that of the whole rose with equal mass, and when the fragrance enhancing agent is selected from rose extracts, the tea water purity of the rose black tea is poor during brewing.

In summary, the above examples and comparative examples exhibit the following trends in the course of comparison: compared with the method of directly fermenting the rose flavor substances and black tea which is not fermented and fried together, the co-treatment of the finished black tea and the rose flavor substances can effectively improve the content of the fragrance substances such as citronellol, geraniol and the like in the rose black tea, increase the fragrance of the rose black tea and reduce the sour and astringent taste of the rose black tea after brewing. In addition, in the treatment process, the containers with holes on the side walls are used for preventing light and ventilating, so that the flavor of the rose black tea is improved, and the sour and astringent feeling is reduced. In addition, the rose essential oil is selected as the flavor substance, which is beneficial to improving the purity of tea water brewed by the rose black tea. After the processing is finished, the fragrance is further improved, so that the fragrance of the rose black tea leaves and the fragrance of tea water brewed by the rose black tea can be improved.

The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A preparation method of rose black tea is characterized by comprising the following steps: the method comprises the following steps:

s2, drying the reprocessed black tea obtained in the step S1;

2. A process for the preparation of a rose black tea according to claim 1 characterised in that: the rose flavor substance is rose essential oil.

3. A process for the preparation of a rose black tea according to claim 2 characterised in that: the rose essential oil is extracted by a steam distillation method.

4. A process for the preparation of a rose black tea according to claim 2 characterised in that: the addition amount of the rose essential oil is 2.6-4% of the weight of the finished black tea.

5. A process of making a rose black tea according to claim 3 characterised in that: the specific operation method of step S1 is as follows: placing the finished black tea in a container with holes in the side wall, spraying rose essential oil above the finished black tea, turning and uniformly mixing the finished black tea and the rose essential oil, then placing the finished black tea in a ventilated place and keeping out of the sun, controlling the temperature to be 15-25 ℃, and storing for 20-30 hours to obtain the reprocessed black tea.

6. A process for the preparation of a rose black tea according to claim 1 characterised in that: the finished black tea is Keemun black tea.

7. A process for the preparation of a rose black tea according to claim 1 characterised in that: after step S2 is finished, the method further includes the following steps:

and S3, carrying out fragrance improvement treatment on the dried rose black tea for 1-3 times.

8. A method of making a rose black tea according to claim 6 characterised in that: in the step S3, the aroma raising agent used in the aroma raising treatment process is rose petals, and the adding weight of the rose petals is 0.7-1.2% of the weight of the finished black tea.

9. The rose black tea is characterized in that: prepared by the method of any one of claims 1 to 8.