CN113826738B

CN113826738B - Preparation method of fermented tea containing golden dew plum

Info

Publication number: CN113826738B
Application number: CN202111038511.9A
Authority: CN
Inventors: 李彩霞; 马世震; 冯海生; 宋文珠; 许显莉; 多杰措
Original assignee: Northwest Institute of Plateau Biology of CAS
Current assignee: Northwest Institute of Plateau Biology of CAS
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2024-03-15
Anticipated expiration: 2041-09-06
Also published as: CN113826738A

Abstract

The invention relates to the technical field of tea preparation, in particular to a preparation method of fermented tea containing golden dew plum. The preparation method is realized by processing and fermenting the golden plum leaves. The method is simple, has low cost, effectively reduces the traditional Chinese medicine qi of the golden plum tea, increases the tea flavor, improves the taste and simultaneously maintains the nutrition components in the tea. Wherein the total of 74 compounds are detected and classified as aldehydes, hydrocarbons, ketones, esters, acids, terpenes, alcohols, and other compounds. The amino acid content is 13.88 to 16.51 percent, and the nutrition value and the health care effect are good; the total flavone content is 10.91-12.71%; the polyphenol content is 8.9-10.1%; protein content 14.2-16.9%; the total ash content is 4.4-4.9%, the polysaccharide content is 0.96-2.14%, and the crude fiber content is 16.7-18.0%, all of which meet the national standard. Wherein, the total flavone content is far higher than that of other common tea varieties.

Description

Preparation method of fermented tea containing golden dew plum

Technical Field

The invention relates to the technical field of tea preparation, in particular to a preparation method of fermented tea containing golden dew plum.

Background

The golden plum (Potentilla fruticosa L.) is also called golden plum, medicinal king tea and golden wintersweet, and is a leaf shrub of Potentilla genus of Rosaceae family, and is distributed in grasslands, forest edges and mountain shrubs with the altitude of 1000-4500 m, and has abundant biological resources. The golden plum mainly contains active ingredients such as flavonoid, triterpenes, polysaccharide tannins, quinones and the like. It is reported that the golden plum leaf can be used for clearing summer heat, nourishing brain, clearing heart, regulating menstruation and invigorating stomach, and the flower can be used for treating leucorrhea with red and white discharge in Tibetan medicine, and the stem can be used for treating diseases such as dyspepsia and cough in Mongolian medicine. In addition, the research on the dewing plum has the functions of inhibiting bacteria, reducing blood sugar and resisting myocardial ischemia. Therefore, the golden plum has higher medical health care value and development value. The folk history of taking the leaves of the golden plum as a substitute for tea leaves is long, but the research and development related to the tea leaves of the golden plum are less utilized at present.

In the earlier stage, the applicant adopts a green tea process to prepare the golden plum tea, and the golden plum tea has the defects of obvious traditional Chinese medicine qi and lacking the faint scent of common tea. Therefore, changing the tea making process, effectively reducing the traditional Chinese medicine qi of the golden plum tea, increasing the tea flavor, improving the taste and simultaneously retaining the nutritional ingredients in the tea leaves is the key point for preparing the golden plum tea.

Disclosure of Invention

Based on the technical problems, the invention mainly aims at the research to mainly discuss the preparation of the fermented tea of the golden plum by utilizing a fermentation process, and simultaneously utilizes exogenous enzyme to assist fermentation so as to increase the dissolution rate of the tea and improve the nutrition components in the tea, thereby achieving the purpose of improving the taste of the tea of the golden plum and providing a new thought for the development of the tea of the golden plum. Aims at providing a preparation method of the fermented tea with the golden dew plum.

The invention provides a preparation method of fermented tea containing golden syrup plum, which comprises the following specific steps:

step 1, processing the golden plum leaves: collecting fresh leaves of the golden plum which are light green in color, free of disease spots and insect pests; placing a part of the tea in a room, piling for 3-4 hours, allowing the tea to ferment naturally, and then twisting and drying the tea to make the water content reach 70% to prepare the natural fermentation tea of the golden dew plum, namely the tea I for later use; the other part is evenly spread at a shade place for 4 to 6 hours, and the middle part is turned over for 1 time; then stir-frying in a tea frying pan, rolling and drying the stir-fried tea to ensure that the water content reaches 70%, and preparing the golden syrup plum stir-fried tea, namely No. II tea for later use;

step 2, fermentation: and (3) fermenting the tea I and the tea II processed in the step (1) by using a fermentation material, wherein the fermentation temperature is 28-40 ℃, the fermentation time is 4-18 h, and the addition amount of the fermentation material is 1.5-3%.

Further, the fermentation material in the step 2 is saccharomycetes and exogenous enzyme, wherein the exogenous enzyme is food-grade cellulase, hemicellulase or pectinase; the fermentation temperature of the saccharomycetes is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the fermentation temperature of the exogenous enzyme is 40 ℃, the fermentation time is 18 hours, and the addition amount is 3 percent.

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

the method is simple, has low cost, effectively reduces the traditional Chinese medicine qi of the golden plum tea, increases the tea flavor, improves the taste and simultaneously maintains the nutrient components in the tea. Wherein the total of 74 compounds are detected and classified as aldehydes, hydrocarbons, ketones, esters, acids, terpenes, alcohols, and other compounds. The quality analysis finds that: contains 7 amino acids necessary for animals, has amino acid content of 13.88-16.51%, and has good nutritive value and health promotion effect; the total flavone content is 10.91-12.71%; the polyphenol content is 8.9-10.1%; protein content 14.2-16.9%; the total ash content is 4.4-4.9%, the polysaccharide content is 0.96-2.14%, and the crude fiber content is 16.7-18.0%, all of which meet the national standard. Wherein, the total flavone content is far higher than that of other common tea varieties.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in connection with the embodiments, and it is obvious that the described embodiments are only some embodiments of the present invention, but 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.

Example 1

Parameter optimization test of the method

1. Influence of fermentation and brewing parameters on quality of golden plum tea

(1) Instrument and materials

Main instrument and model: BPG-9140A type precision blast drying oven (a constant scientific instrument Co., ltd.), ML204T type electronic balance (Metrele-Tolyduo instrument Shanghai Co., ltd.), SL-500A type high-speed multifunctional pulverizer (Zhejiang Yongkang, ping Qing hardware Co., ltd.), motion 18220DXG type mol water purifier (Chongqing Mole Water treatment facilities Co., ltd.), HW-SY21-KP4 type intelligent thermostatic water bath (Beijing Long wind instrument Co., ltd.), rotary evaporator RE-52AA (Shanghai Asian Biochemical instrument Co., ltd.), circulating water type multipurpose vacuum pump (Henan Xinyang, ancient cooking tea science Co., ltd.), electronic temperature-controlled tea frying pot (Henan Xinyang, henan Yiding tea science Co., ltd.).

The leaves of Hainan were obtained from the village of the county of the middle of the Qinghai province, jiaxiang (east longitude 101 deg. 40'41.5 ", north latitude 36 deg. 18' 41.8", altitude 3040 m). The yeast is obtained from Xinjiang lifting biotechnology Co., ltd, and the cellulase (food grade), hemicellulase (food grade) and pectase (food grade) are obtained from Zhejiang Yinuo biotechnology Co., ltd. Other chemical reagents were purchased locally and were all analytically pure.

(2) Processing of leaves of Hawthorn fruit

Collecting fresh leaves of the golden plum which are light green in color, free of disease spots and insect pests; placing a part of the tea leaves in a room, piling for 3-4 hours, allowing the tea leaves to ferment naturally, and then twisting and drying the tea leaves to make the water content reach 70% to prepare the natural fermentation tea of the golden dew plum, namely the tea of No. I, for later use; the other part is evenly spread at a shade place for 4 to 6 hours, and the middle part is turned over for 1 time; then stir-frying in a tea frying pan, rolling and drying the stir-fried tea to ensure that the water content reaches 70%, and preparing the golden syrup plum stir-fried tea, namely No. II tea for later use;

(3) Fermentation condition optimization

Since fermentation has an important influence on the quality of the golden plum tea. Therefore, orthogonal tests are designed by controlling factors affecting fermentation effects, including exogenous enzyme types, exogenous enzyme addition amounts, fermentation temperatures, fermentation times, and the like. The test materials are respectively No. I tea and No. II tea, the fermentation material is yeast, and L9 (3 ⁴ ) Orthogonal test (tables 1 and 2). Wherein, I tea is used as a test material, and tea obtained by carrying out orthogonal test of numbers 1-9 is named as 1-9; the tea leaves obtained by carrying out the orthogonal test of numbers 11-19 were designated as numbers 11-19 by using the tea No. II as a test material, and sensory evaluation was carried out respectively.

TABLE 1 orthogonal test factors and levels with Yeast as fermentation Material

TABLE 2 orthogonal test Table with Yeast as fermentation Material

Uses tea I and tea II as materials, uses cellulase, hemicellulase and pectase as fermentation materials, selects L9 (3) ⁴ ) Orthogonal tests (tables 3, 4) and sensory evaluation were performed. Wherein, I tea is used as a test material, and the positive numbers 21-29 are carried outThe tea obtained by the cross test is named 21-29; the tea leaves obtained by carrying out the orthogonal test of numbers 31-39 by using the tea No. II as a test material were designated as numbers 31-39.

TABLE 3 orthogonal test factors and levels

TABLE 4 orthogonal test chart

(4) Sensory evaluation

Sensory evaluation adopts a double-blind test method, and sensory evaluation is carried out on the apparent soup color, the brightness, the taste, the aroma and other quality characteristics of the fermented tea of the golden plum according to GB/T14487-2017 tea sensory evaluation terminology, wherein the weight of an evaluation factor is distributed for 3 times for soup color (20%), aroma (20%), taste (30%), clarity (30%), and the like.

(5) Brewing factor test

The tea ratio, brewing time and brewing times of the fermented tea of the golden plum are tested by taking the soup color, the taste, the aroma, the clarity and the extract as sensory indexes;

(1) tea ratio selection

Taking 3g of No. 23 product, and setting tea water ratios to be 1: 150. 1: 100. 1:50 and 1:30, respectively placing in a water bath kettle at 100 ℃ for 10min, discharging soup, filtering while the soup is hot, fixing the volume to obtain tea soup, measuring the water extract content by adopting a gravimetric method, and checking.

(2) Selection of brewing time

Taking 3g of No. 23 product, soaking with 150ml boiling water, placing in a water bath kettle at 100 ℃, taking out soup, filtering while the soup is hot, respectively setting the soaking time to be 1min, 5min, 10min and 15min, measuring the water extract content by adopting a gravimetric method, and carrying out price examination.

(3) Selection of brewing times

Taking 3g of No. 23 product, soaking with 150ml boiling water, placing in a water bath kettle at 100deg.C for 10min, discharging soup, filtering while hot, and constant volume to obtain tea soup, respectively setting soaking times to 1, 2 and 3 times, measuring water extract content by gravimetric method, and checking price.

(6) Optimizing results

(1) Fermentation optimization result using saccharomycetes as fermentation material

The results of the sensory evaluation are shown in tables 5 and 6. The study found that the fermented tea sample had a pronounced vinasse taste. The fermentation temperature, the fermentation time and the addition amount have little influence on the color of the golden plum tea soup, the golden plum tea soup is light yellow or yellow, and the taste is purer; other samples were less clear than No. 4 and No. 14; no. 4 has faint scent, and in other samples, the medicinal qi is obviously weakened and slightly fragrant compared with the stir-fried tea. The specific process conditions are as follows: the temperature is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the sensory evaluation result is synthesized, and the No. 4 optimal tea is obtained by taking the No. I tea as a test material; no. 14 is the best among the golden plum teas obtained by using No. II tea as the test material.

Table 5 sensory evaluation of fermented tea of Hamamelis (Yeast-tea No. I)

Table 6 sensory evaluation of fermented tea of Hawthorn fruit (Yeast-tea No. II)

(2) Fermentation optimization result using exogenous enzyme as fermentation material

As can be seen from tables 7 and 8, the tea-like soup after fermentation is yellowish or yellow, and has purer taste; the aroma components of different samples are different, the No. 23 and the No. 33 are obvious fresh aroma, and the aroma of other treatments is light; 21. the tea soups of samples 26, 28, 31, 36 and 38 were bright in color and the clarity of the other treatments was poor. Combining sensory evaluation results, wherein the No. 23 and No. 26 golden plum tea obtained by taking the No. I tea as a test material is optimal; among the golden plum teas obtained by using tea No. II as a test material, the golden plum teas No. 33 and No. 34 are the best. The specific process conditions are as follows: pectase is used for auxiliary fermentation, the temperature is 40 ℃, the fermentation time is 18 hours, and the addition amount is 3 percent.

Table 7 sensory evaluation of fermented tea of Hamamelis (enzyme-I tea)

Table 8 sensory evaluation of fermented tea of Hamamelis (enzyme-II tea)

(3) Brewing factor test results

A. Tea ratio selection

Under different tea-water ratio conditions, the clarity of the fermented tea of the golden plum is brighter. With the decrease of the tea water ratio, the water quantity is gradually reduced, the soup color is changed from light yellow to orange yellow, the taste is changed from flat to pure, the fragrance is changed from light to faint scent, and the extract content has no obvious change rule. When the tea water ratio is 1: at 50, the extract content was the highest, 19.35%. The evaluation results are combined, and the tea water ratio of the golden plum fermented tea is 1:50 is preferred (Table 9).

TABLE 9 sensory evaluation results of fermented tea of Hawthorn fruit under different tea ratios

B. Selection of brewing time

Under the condition of different brewing time, the clarity of the fermented tea of the golden plum is brighter. With the extension of the brewing time, the color of the fermented tea soup of the golden plum is gradually deepened, the light yellow is changed into light yellow, then the orange yellow is changed into pure, the taste is changed from flat to pure, the fragrance is changed from light to faint scent, and the content of extract is changed from low to high. Based on the above evaluation results, the brewing time of the fermented tea of the golden plum is preferably 5 to 10 minutes (Table 10).

TABLE 10 sensory evaluation results of fermented tea of Hawthorn fruit under different brewing time conditions

C. Selection of brewing times

Under the condition of different brewing times, the clarity of the fermented tea of the golden plum is brighter. Along with the extension of the brewing times, the color of the fermented tea soup of the golden plum is gradually lightened, the orange is changed into light yellow, the taste is flat and light, the aroma is lightened, and the content of extract is reduced. In particular, the extract content of the second brew drops drastically, less than 1/4 of the first brew. The above evaluation results were combined, and the brewing times of the fermented tea of the golden plum should not exceed 2 times (Table 11).

TABLE 11 sensory evaluation results of fermented tea of Hawthorn fruit under different brewing times conditions

(6) Conclusion(s)

Proper fermentation temperature, time, addition amount and enzyme have little influence on the soup color and taste of the fermented tea of the golden plum, and have great influence on clarity and aroma. Fermenting with saccharomycetes to obtain No. 4 and No. 14 products with good quality, wherein the specific process conditions are as follows: the temperature is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the No. I tea and the No. II tea are used as test materials, and different enzymes are used for fermentation preparation, so that the quality of the No. 23 and No. 33 finished products is good, and the specific process conditions are as follows: pectase is used for auxiliary fermentation, the temperature is 40 ℃, the fermentation time is 18 hours, and the addition amount is 3 percent.

2. Analysis of volatile components of fermented tea of golden plum

According to the optimization of the primary fermentation process, a better golden plum fermented tea sample is screened, and the detection and analysis of the volatile components of the golden plum fermented tea are carried out by adopting a solid-phase microextraction and gas-phase chromatography combined technology, so as to compare the component differences.

Samples No. 23 (tea No. I) and No. 33 (tea No. II) were taken for volatile component analysis.

(1) Method of

Weighing 2g of a fermented tea sample of the golden plum, putting the sample into a headspace bottle, inserting an aged 50/30 mu m CAR/PDMS/DVB extraction head into the headspace part of the sample bottle through a rubber pad of a bottle cap, adsorbing for 30min at 60 ℃, taking out the adsorbed extraction head, inserting the extraction head into a gas chromatography sample inlet, desorbing for 3min at 250 ℃, and starting an instrument to collect data;

gas-mass spectrometer conditions: the chromatographic column was HP-5MS,30 m.times.250 μm.times.0.25. Mu.m; gas chromatography conditions: the initial temperature is 30 ℃, and the temperature is kept for 5min; raising the temperature to 50 ℃ at 3 ℃/min, and keeping for 3min; raising the temperature to 150 ℃ at 5 ℃/min; raising the temperature to 250 ℃ at 20 ℃/min, and keeping for 5min; the temperature of the sample inlet is 260 ℃; carrier gas flow rate (He) 1.5mL/min; sample injection in a non-split mode; mass spectrometry conditions: electron bombardment ionization mode, electron energy 70eV; full spectrum scanning, wherein the mass scanning range is 29-400 u; quadrupole rod detector temperature 150 ℃. Qualitative analysis of the compounds was performed using NIST11 spectral library search (MS).

(2) Results

The volatile components of the fermented tea of the golden plum are detected by adopting a solid-phase microextraction and gas chromatography combined technology, and 80 components are detected totally, wherein the number 23 and the number 33 samples have 42 components. As is clear from Table 12, 56 kinds of components were detected in total in sample No. 23, and the detected compounds were classified into aldehydes (13 kinds), hydrocarbons (5 kinds), ketones (7 kinds), esters (1 kind), acids (4 kinds), terpenes (5 kinds), alcohols (13 kinds), and other compounds (8 kinds). The volatile components of the No. 23 sample mainly comprise aldehyde compounds and alcohol compounds, and among the volatile components, cis-linalool oxide (11.7%), linalool (10.09%) and eugenol (10.98%) have the highest content, and trans-linalool oxide (7.01%) and phenethyl alcohol (8.89%) have higher content. The aroma components with higher content mainly show flower aroma, fruit aroma, faint scent and the like, are the material basis of the flower aroma and the fruit aroma of the fermented tea of the golden plum, and play an important role in forming the aroma quality of the fermented tea of the golden plum.

Sample 33 detected 66 components in total. The compounds detected can be classified into aldehydes (17), hydrocarbons (7), ketones (10), esters (1), acids (5), terpenes (5), alcohols (14), and other compounds (7). The volatile components of sample number 33 are mainly aldehydes and then alcohols. The volatile components of sample No. 33 contained the highest levels of nonanal (6.67%) and trans-2- (2-pentenyl) furan (6.81%). Wherein, the nonanal has fragrance of rose, orange, etc., the linalool has lily fragrance, and the trans-linalool oxide has rosemary (table 12).

TABLE 12 results of testing volatile ingredients of fermented tea of Hamamelis virginiana

(3) Conclusion(s)

Tea aroma is an important index for evaluating tea quality and is also an important point of tea quality chemistry research. The tea aroma is actually the characteristic aroma of tea formed by combining different aromatic substances in different concentrations and comprehensively acting on olfactory nerves. Tea aroma is a mixture of numerous volatile materials of varying nature, slightly reduced content and greatly varying.

In the previous study, 49 ingredients are detected in total from volatile ingredients of the golden plum fried tea, and the detected compounds can be divided into aldehydes (12), hydrocarbons (11), ketones (8), esters (6), acids (3), terpenes (3), alcohols (2) and other compounds (4), wherein the content of nonanal and N-phenyl-N-ethyl-p-isopropylbenzamide is the highest and is more than 10%; the content of 2, 4-heptadiene and 3, 5-octadiene-2-ketone is higher and is between 5 and 10 percent. This shows that after fermentation, the volatile components were changed in type and content (Table 13).

TABLE 13 test results of volatile ingredients of golden plum tea

In our study, it was found that the volatile components of samples No. 23 and No. 33 were mainly aldehydes and alcohols, which are consistent with the major compound species of most tea aroma components. Among the volatile components of sample No. 23, cis-linalool oxide (11.7%), linalool (10.09%) and eugenol (10.98%) were highest, trans-linalool oxide (7.01%) and phenethyl alcohol (8.89%) were higher, which suggests that the golden prune shares the same aroma components as black tea.

3. Analysis of quality of fermented tea of golden plum

The content of the main chemical components in the tea is an important index for evaluating the quality of the tea. The method selects the golden plum tea samples with better sensory evaluation for quality analysis, respectively determines the contents of total flavone, polyphenol, protein, ash, polysaccharide, crude fiber and amino acid in the samples, and performs comparative analysis on the contents of other common tea components, thereby providing reference for development and utilization of golden plum resources.

And selecting No. 4, no. 23, no. 26, no. 33, no. 34 and No. 38 finished products for quality analysis and comparison.

(1) Method of

The total flavone is measured according to GB/T20574-2006, the protein is measured according to national standard GB5009.5-2010, the polyphenol is measured according to national standard GB/T8313-2008, the amino acid is measured according to GB/T5009.124-2003, the ash is measured according to GB/T8306-1987, the polysaccharide is measured by anthrone colorimetric method, and the crude fiber is measured according to GB/T6434-94. The component analysis was measured by the analysis center of the North-west high-primordial biological research institute of China academy of sciences. The biological active ingredients of the fermented tea of the golden plum are subjected to analysis of variance by adopting SPSS19.0 software.

(2) Results

(1) Total flavone

The total flavone content of 6 kinds of fermented tea of bougainvillea spectabilis was measured (Table 14). The total flavone content of the 6 kinds of golden syrup plum fermented tea is between 10.91 and 12.71 percent, wherein the number 4 is the highest, the number 26 is the lowest, and the number 10.91 percent; analysis of variance shows that there are significant differences in the content of the 6 treatments except for No. 23 and No. 38. Compared with the domestic tea flavone content (Table 15), the total flavone content of the fermented tea of the golden plum is far higher than that of several domestic tea flavone contents.

TABLE 14 determination of the Main ingredient content of fermented tea of Hamamelis virginiana

Note that: the lower case letters of the same column indicate significant differences (P < 0.05).

TABLE 15 flavone content in different tea leaves

(2) Polyphenols

Tea polyphenol is one of indexes reflecting the quality of tea, is the most important bioactive substance in tea, and is a contributor to bitter and astringent taste of tea soup. In general, the higher the tea polyphenol content, the better the tea (especially green tea) quality. The research shows that the tea polyphenol content in different tea leaves is ordered as follows: green tea > white tea > yellow tea > green tea > black tea (table 16). The polyphenol content of 6 kinds of fermented tea of bougainvillea spectabilis was measured (Table 14). The content of 6 kinds of fermented tea polyphenols of the bougainvillea spectabilis is 8.9-10.1%. Analysis of variance showed no significant differences between No. 23, no. 4, and No. 33, no. 34, and No. 38, and No. other treatments. The polyphenol content of the fermented tea of the golden plum is lower than that of green tea, black tea, green tea, white tea and yellow tea, and is similar to that of black tea.

TABLE 16 polyphenol content in different tea leaves

(3) Proteins

The protein content of 6 fermented teas of bougainvillea spectabilis was determined (Table 14). The protein content of the 6 treated fermented golden plum tea is 14.2-16.9%, and the protein content of the 6 treated fermented tea has obvious difference. The protein content of the 6 treated fermented tea is sequentially from high to low: no. 4 is more than 23, no. 34 is more than 38, no. 26 is more than 33, wherein the content of No. 4 is 16.9% the highest, and the content of No. 33 is 14.2% the lowest. The highest protein content of green tea is 35.97%; about 30% of Zhengshan species, jinjunmei and the like; the protein content of different Dahongpao varieties ranges from 24.65% to 28.17%. Therefore, the protein content of the fermented tea of the golden plum is lower than that of common tea varieties.

(4) Total ash content

The tea quality evaluation comprises 3 aspects of tea safety index evaluation, physical and chemical index evaluation and sensory quality evaluation, and the limitation of ash content belongs to the category of physical and chemical indexes, so that the tea ash is the only index with quality judgment significance and sanitary inspection significance in the physical and chemical indexes of the tea. Too low an ash content of the tea leaves may be false tea, and too high an ash content indicates that the tea leaves are polluted by sediment, dust and the like. The ash content of 6 fermented teas of bougainvillea spectabilis was determined (table 14). The total ash content of the 6 kinds of fermented tea of the golden dew plum is between 4.4 and 4.9 percent, which accords with the national standard (4.0 to 8.0 percent). The total ash content of several teas was determined (Table 17). Compared with other common tea varieties, the fermented tea of the golden plum has lower total ash content.

TABLE 17 Total ash in different varieties of tea leaves

(5) Polysaccharide

The polysaccharide content of 6 kinds of fermented tea of bougainvillea spectabilis was measured (Table 14). The content of 6 kinds of fermented tea polysaccharide of the golden syrup plum is between 0.96 and 2.14 percent, and the content of 6 kinds of treated fermented tea polysaccharide has obvious difference. The 6 treated fermented tea polysaccharide contents are sequentially from high to low: no. 38 > 23 > 33 > 34 > 4 > 26. Wherein the content of No. 38 is highest, 2.14%, and the content of No. 26 is lowest, 0.96%. The fermented tea polysaccharide content of the golden plum was lower than the domestic famous tea soluble total sugar content (Table 18). The polysaccharide content of the finished tea is not only influenced by the factors of fresh She Laonen degrees, variety, tea garden management, climate conditions, production places and the like, but also is a non-negligible factor in the tea making process. In order to fully utilize the original substance basis in fresh leaves and improve the quality factors such as tea color, aroma and taste, the proper conditions should be mastered in the tea making technology, so that the polysaccharide is promoted to have more hydrolysis, and the excessive useless consumption of the soluble sugar is prevented, so that the content of the soluble sugar is increased and the tea quality is improved.

Table 181 total soluble sugar content in tea leaves of different varieties

(6) Coarse fibers

As early as 60 s, crude fibres were listed in international recommendation ISO 3720 specification for black tea, specifying a maximum limit of 16.5%. Crude fiber is used as a tea tender mark, and domestic and foreign researches tend to be consistent: coarse fibers are significantly inversely related to tea tenderness. Cellulose gradually accumulates as the tea shoots develop. The more cellulose, the lower the tea tenderness, and conversely the higher the tea tenderness. Therefore, the finished tea with excellent color, fragrance, taste and shape can be prepared only on the premise of high picking tenderness. The crude fiber content of 6 kinds of fermented tea of bougainvillea spectabilis was measured (Table 14). The content of the crude fiber of the 6 treated fermented teas is between 16.7 and 18.0 percent, and the content is obviously different. The content of the crude fiber of the treated fermented tea is sequentially from high to low: no. 4 > 23 > 34 > 38 > 26 > 33, wherein the content of No. 4 is the highest, 18.0%, and the content of No. 33 is the lowest, 16.7%. Compared with the national standard (the crude fiber content is less than or equal to 16.5 percent), the crude fiber content of the fermented tea is higher than the standard.

(7) Amino acids

The amino acid content of 6 kinds of fermented tea of bougainvillea spectabilis was measured (Table 14). The fermented tea of the golden plum is rich in various amino acids, wherein the contents of tyrosine, aspartic acid, arginine, lysine, histidine and phenylpropyl are high, the contents of the tyrosine, the aspartic acid, the arginine, the lysine, the histidine and the phenylpropyl are all more than 1%, and the content of cysteine is the lowest. 6 kinds of treated fermented tea have total amino acid content of 16.51% and highest No. 4; secondly, the number 23, the number 34, the number 38 and the number 26; 33 is the lowest and is 13.88%. The fermented tea of Hawthorn fruit contains 7 amino acids essential to animal body, and the essential amino acids are lysine > phenylalanine > isoleucine > threonine > leucine > valine > methionine in sequence (Table 19). According to the ideal mode of FAO/WHO, the ratio (EAA/TAA) of essential amino acids to total amino acids of protein amino acid composition with better quality is about 40%, the ratio (EAA/NEAA) of essential amino acids to non-essential amino acids is above 60%, and the amino acid composition of the fermented tea of the golden plum meets the ideal mode of FAO/WHO. The content of the essential amino acid lysine in the fermented tea of the golden plum is highest, and the essential amino acid lysine accounts for 8.01 percent of the total amino acid. Therefore, the fermented tea of the golden plum should have good nutritional value and health care effect.

TABLE 19 amino acid content (%)

Note that: * Represents essential amino acids and flavor amino acids.

Because black tea is a fully fermented tea, the comparison of the golden plum fermented tea and the Chinese and international black tea standards is necessary, and the method has certain reference significance for the establishment, production, processing, consumption and the like of golden plum fermented tea enterprises.

Currently, the international standard for black tea is ISO 3720. The export and import countries of the main black tea also have corresponding national standards. Because of the very many types of Chinese black tea products and the characteristics of the products, china sets the most relevant standards of black tea, classifies the black tea as the finest, is quite different from the international standard, and releases and implements the recommended national standard GB/T13738 of black tea in China successively and is divided into three parts (broken black tea, congou black tea and black tea of small species) (Table 20).

TABLE 20 physicochemical index (%)

Note that: "-" indicates that the standard does not specify this index.

Compared with Table 20, the total ash content of the 6 kinds of golden syrup plum fermented tea is 4.4-4.9%, which accords with the national standard GB/T13738; the content of the 6 kinds of golden syrup plum fermented tea polyphenols is 8.9-10.1%, except for No. 26, the other 5 kinds of processing meet the national standard; the content of the crude fiber of the 6 treated fermented teas is 16.7 to 18.0 percent, which exceeds the national standard GB/T13738.

The content of different components in the golden plum leaves in different months is measured, and the result shows that the content of amino acid, polyphenol and protein reaches the highest in 6 months, the content of total flavone and vitamin C reaches the highest in 9 months, and the content of catechin, tannin and rutin reaches the highest in 8 months. Therefore, the content of the active ingredients in the golden plum leaves is greatly affected in different months. The main component analysis method is used to screen out 5 indexes of total flavone, catechin, protein, amino acid and polyphenol, which can represent the quality of the golden plum.

Example 2

A preparation method of a fermented tea containing flos Rhododendri mollis comprises the following specific steps:

step 1, processing the golden plum leaves: collecting fresh leaves of the golden plum which are light green in color, free of disease spots and insect pests; placing a part of the tea leaves in a room, piling for 3-4 hours, allowing the tea leaves to ferment naturally, and then twisting and drying the tea leaves to make the water content reach 70% to prepare the natural fermentation tea of the golden dew plum, namely the tea of No. I, for later use; the other part is evenly spread at a shade place for 4 to 6 hours, and the middle part is turned over for 1 time; then stir-frying in a tea frying pan, rolling and drying the stir-fried tea to ensure that the water content reaches 70%, and preparing the golden syrup plum stir-fried tea, namely No. II tea for later use;

step 2, fermentation: taking the tea I and the tea II processed in the step 1, and fermenting by using a fermentation material; the fermentation material is saccharomycete and exogenous enzyme, wherein the saccharomycete is food-grade dry saccharomycete purchased from Xinjiang lift biotechnology limited liability company; the exogenous enzyme is food grade cellulase, hemicellulase or pectase purchased from Zhejiang Yinuo biotechnology Co., ltd; the fermentation temperature of the saccharomycetes is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the fermentation temperature of the pectase of the exogenous enzyme is 40 ℃, the fermentation time is 18 hours, and the addition amount is 3 percent.

Example 3

step 2, fermentation: taking the tea I and the tea II processed in the step 1, and fermenting by a fermentation material, wherein the fermentation material is saccharomycetes and exogenous enzymes, and the saccharomycetes are food-grade dry saccharomycetes purchased from Xinjiang lifting biotechnology Limited liability company; the exogenous enzyme is food grade cellulase, hemicellulase or pectase purchased from Zhejiang Yinuo biotechnology Co., ltd; the fermentation temperature of the saccharomycetes is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the fermentation temperature of the exogenous enzyme cellulase is 30 ℃, the fermentation time is 12 hours, and the addition amount is 3 percent.

Example 4

step 2, fermentation: taking the tea I and the tea II processed in the step 1, and fermenting by a fermentation material, wherein the fermentation material is saccharomycetes and exogenous enzymes, and the saccharomycetes are food-grade dry saccharomycetes purchased from Xinjiang lifting biotechnology Limited liability company; the exogenous enzyme is food grade cellulase, hemicellulase or pectase purchased from Zhejiang Yinuo biotechnology Co., ltd; the fermentation temperature of the saccharomycetes is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the fermentation temperature of the exogenous enzyme cellulase is 40 ℃, the fermentation time is 6 hours, and the addition amount is 2 percent.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

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

2. The method for preparing fermented tea of bougainvillea spectabilis as claimed in claim 1, wherein the fermented material in the step 2 is yeast and exogenous enzyme, wherein the exogenous enzyme is food-grade cellulase, hemicellulase or pectinase; the fermentation temperature of the saccharomycetes is 28 ℃, the fermentation time is 4 hours, and the addition amount is 1.5 percent; the fermentation temperature of the exogenous enzyme is 40 ℃, the fermentation time is 18 hours, and the addition amount is 3 percent.