CN118077789A - Emmyophyllus-like fermented tea and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of tea making processes, and particularly relates to an Elmiting basket-shaped fungus fermented tea and a preparation method thereof. The invention provides a preparation method of fermented tea of Emi stokes basket-like bacteria, which takes summer black tea as a raw material, inoculates the Emi stokes basket-like bacteria into tea for solid state fermentation, and prepares the fermented tea after culturing and drying. The tea making process provided by the invention takes tea leaves as a culture medium for growth of the Aim stokes basket bacteria on the premise of not adding any culture auxiliary materials, and the whole process has no external pollutants, so that the safety of products is ensured. The prepared fermented tea has stronger fragrance than summer black tea; the color of the tea soup is deeper than that of summer black tea, and the taste is more mellow and sweet than that of summer black tea. The invention improves the quality of summer black tea, gives the product unique fungus fragrance, and is a good health-care drink.

Description

Emmyophyllus-like fermented tea and preparation method thereof

Technical Field

The invention belongs to the technical field of tea making processes, and particularly relates to an Elmiting basket-shaped fungus fermented tea and a preparation method thereof.

Background

Tea is considered one of the most popular beverages worldwide. Tea leaves are internally rich in various chemical components such as caffeine and various vitamins, which help promote faster oxidation of fats. Compared with spring tea, summer black tea has stronger bitter taste. Because the summer tea has bitter taste, the resource utilization of the summer tea is limited. In the production process of tea leaves, fermentation generally plays a vital role, and the chemical constitution of the tea leaves can be changed through the fermentation process, so that the sensory experience and the overall quality of the tea leaves are greatly influenced. The fermentation process can change the smell of the tea, improve the taste and the aftertaste of the tea, and relieve the astringency and the bitter taste of the tea so that the taste of the tea becomes stronger.

The Liupu tea belongs to post-fermentation tea, belongs to black tea, and is different from other five kinds of black tea, and the black tea is thick in soup, mellow in taste and fragrant, and mainly because microorganisms continuously perform physiological activities in the links of black tea manufacturing, aging, storage and the like, the sensory quality of the black tea is improved. Wherein the Aim Stokes basket is a dominant strain separated from Liupu tea, belonging to the genus Penicillium in the fungus kingdom. The polysaccharide has a plurality of enzyme activities such as polysaccharide monooxygenase, cellulase, beta-glucosidase and the like, and can degrade and convert substances such as cellulose, hemicellulose and the like. Moreover, different eskiosks exert different main effects in black tea. However, there is no report of the use of Elmatoxylum in fermenting tea. Considering that the main effects exerted by different rice basket bacteria in tea leaves can be different, if an Aim basket bacterial strain capable of improving bitter taste of summer black tea can be obtained, the Aim basket bacterial strain must play an important positive role in summer tea production and utilization.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a preparation method of the fermented tea of the Emi stokes basket bacteria, which is prepared by solid state fermentation of tea leaves and the Emi stokes basket bacteria under a certain condition, and the prepared fermented tea of the Emi stokes basket bacteria has special fungus aroma, mellow and refreshing taste, sweet and smooth taste, and the like, and overcomes the problems of bad taste of black tea in summer.

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

The first aspect of the invention provides a preparation method of an achyranthes aspera fermented tea, which comprises the steps of taking summer black tea as a raw material, inoculating the achyranthes aspera on tea to perform solid state fermentation, and drying to obtain the achyranthes aspera fermented tea.

Preferably, the preparation method of the fermented tea of the Emi stokes basket bacteria specifically comprises the following steps: sterilizing summer black tea, adding spore suspension of Acidovorax striatum and sterile water, sealing, fermenting at 28-32deg.C and 80-90% humidity for 3-15 days, and drying.

More preferably, the Eimeria is a fungus of the genus Zymomonas, the genus Talaromyces being named amestolkiae; the Elmatoxylum is purchased from China center for type culture Collection, and the strain number is: 15150000000; the strain deposit number is: CCTCCAF2021087.

After sterilizing the finished summer black tea, adding the spore liquid of the Aim stokes basket bacteria into the tea for solid fermentation, so that the tea and the Aim stokes basket bacteria are mutually infiltrated and fused, and after common fermentation, unique fungus fragrance and mellow taste are generated, and then the fermented tea is prepared by drying; the fermented tea has stronger fragrance than summer black tea; the color of the tea soup is deeper than that of summer black tea, and the taste is more mellow and sweet than that of summer black tea, so that the problems of poor taste and the like of summer black tea are solved.

More preferably, the preparation method of the summer black tea comprises the following steps: withering black tea young shoots picked in summer for 14-18 hours at room temperature, and twisting for 1-3 hours; fermenting at 28-30deg.C and 85-90% humidity for 5-9 hr, and drying.

More preferably, the fermentation culture is carried out for a period of 3 to 6 days. Wherein, when fermenting for 6 days, the flavor quality of the fermented black tea reaches the best.

More preferably, the spore suspension has a concentration of 1.0 to 0.5X10 ⁷ CFU/mL.

More preferably, the ratio of the black tea, spore suspension and sterile water is 50-70g:2-4mL:10-15mL.

More preferably, the black tea includes (but is not limited to) black tea of english No. nine.

More preferably, the spore suspension is made from spores produced by a second generation of eimeria stokes basket.

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

fungi play an important role in the tea fermentation process, and in order to improve the bitter taste of the black tea in summer, the invention firstly cultures the Aim-Stokes basket with tea in a co-fermentation way, so as to develop the Aim-Stokes basket fermented tea. The tea mainly comprising lignin and cellulose is fermented by the Emi stokes basket bacteria and then is converted into rich microbial fungus nutrition proteins and nutrition components which can be eaten by human bodies or directly absorbed by human bodies, so that the prepared tea product is rich in polysaccharide, amino acid, unsaturated fatty acid, mineral elements and the like; meanwhile, amino acid and derivative substances thereof which cause bitter taste of tea can be converted, and the contents of phenolic acid and saccharide substances with sweet taste are increased, so that the problem that the black tea has strong bitter taste in summer is solved, and the production and the utilization of the black tea are promoted. Therefore, the fermented tea soup of the Acidovorax striatus prepared by the method has ruddy color, pure fragrance, sweet taste, mellow taste and excellent quality, and is a good health-care drink. In addition, on the premise of not adding any culture auxiliary materials, the tea leaves are used as a culture medium for growth of the Aim stokes basket bacteria, and the whole process is free of external pollutants and safe and reliable.

Drawings

FIG. 1 is a diagram showing the sensory quality analysis of a black tea fermented with Eimeria in different fermentation times;

FIG. 2 is a diagram showing the sensory quality analysis of an Elmatoxylum-fermented tea;

FIG. 3 is an electronic tongue analysis bar graph of the fermented tea of Eimeria in different fermentation times;

FIG. 4 is a bar graph of electronic tongue analysis of Eimeria-Stokes fermented tea versus control black tea;

FIG. 5 is a graph of the composition rings of non-volatile metabolite classes of Elmatoxylum-fermented tea and control black tea in positive (a) and negative (b) ion modes;

FIG. 6 is a PCA analysis (a) and a cluster thermogram analysis (b) of non-volatile metabolites of Eimeria-fermented tea and control black tea;

FIG. 7 is a graph of differential metabolite classifications of Eimeria-Stokes fermented tea and control black tea;

FIG. 8 is a graph of differential metabolite clusters of Eimeria-Stokes fermented tea and control black tea (a is the differential metabolite of Ta and YC, b is the differential metabolite of Ta and ZR, c is the differential metabolite of Ta and MJ).

Detailed Description

The following describes the invention in more detail. The description of these embodiments is provided to assist understanding of the present invention, but is not intended to limit the present invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

The experimental methods in the following examples, unless otherwise specified, are conventional, and the experimental materials used in the following examples, unless otherwise specified, are commercially available.

Examples: preparation of fermented tea of Emi Stokes basket-like bacteria

(1) Activating strains: the slant strain of Acidovorax facilis (Talaromycesamestolkiae, strain number: 15150000000; strain number: CCTCCAF 2021087) purchased from China center for type culture collection was placed in an incubator at 30℃for 1d, and then transferred to a plate of PDA medium for 7d at 30℃to activate the strain.

(2) Preparing seed suspension by shaking: and after the strain is activated, carrying out primary streak culture passage, and taking a colony of the secondary passage for subsequent experiments. Adding 3-4mL of sterile water into a culture medium plate for the second passage, blowing the sterile water to wash the surface of a bacterial colony, slightly scraping fresh mould spores on the surface by using a gun head until the sterile water changes color, then sucking spore liquid in the culture medium plate into a new conical flask filled with 7-8mL of sterile water, adding 10-15 glass beads with the diameter of 5mm, sealing by kraft paper, and culturing for 2-3 hours at 180-200 revolutions by using a shaking table to disperse the agglomerated spores. Finally, the mycelia were removed by filtration through 3-4 layers of gauze and the spore suspension was adjusted to 1.0X10 ⁷ CFU/mL with sterile water.

(3) Preparing finished black tea: the picked fresh tea leaves (Yinghong Jiu tea shoot bud 2-3 leaves, picked from the tea base of the national academy of agricultural sciences of Guangdong province) are withered at room temperature for 16 hours; after withering, rolling for 1.5 hours; after rolling, fermenting at 28deg.C and 90% humidity for 6 hr; after fermentation, the black tea was dried at 120℃for 30 minutes and at 85℃for 3.5 hours, thereby obtaining a finished black tea.

(4) Solid state fermentation: each Erlenmeyer flask was filled with 60g of black tea, sterilized at 121℃for 20 minutes, then 3mL of the spore suspension prepared in step (2) and 13mL of sterile water were added, sealed with a gas permeable membrane, placed in an incubator, cultured at 30℃and 85% humidity, and sampled and examined on day 0, day 3, day 6, day 9, day 12 and day 15, respectively.

(5) Fixing tea samples: all samples are placed in an oven for drying for 30 minutes at 95 ℃, taken out and cooled to room temperature, and then re-baked for 15 minutes.

Comparative example: preparation of control Black tea

(1) Control black tea 1, original untreated english red No. nine black tea (YC): the preparation method is the same as in the step (3) of example 1.

(2) Control black tea 2: weighing 60g of the Inulae red nine-colored black tea prepared in the step (3) of the example 1, filling into a conical flask, adding 16mL of sterile water, culturing in an incubator at 30 ℃ and 85% humidity for 6 days without sealing, and fixing to obtain the control black tea 2 (ZR).

(3) Control black tea 3: weighing 60g of Inulae nine red tea prepared in the step (3) of the example 1, placing into a conical flask, sterilizing at 121 ℃ for 15 minutes, adding 16mL of sterile water, sealing with a breathable film, placing into an incubator, culturing for 6 days at 30 ℃ and 85% humidity, and fixing to obtain the control black tea 3 (MJ).

Experimental example 1: comprehensive sensory scoring experiment of fermented tea of Emi stokes basket bacteria under different fermentation time

(1) Experimental method

Aiming at the fermentation tea of the Acidovorax striatus under different fermentation times of the embodiment, 6 professionals carry out sensory scoring on five aspects of appearance, tea soup color, aroma, taste and leaf bottom according to the national tea sensory evaluation method GB/T23776-2018.

(2) Experimental results

As can be seen from fig. 1 and table 1, the fermentation time affects the overall mouthfeel of black tea, especially sweetness. With the extension of fermentation time, the tea soup has dark color, the fungus aroma and taste are increased, the astringency is reduced, the taste is sweet and mellow, and the quality of the black tea is improved. Wherein, when fermenting for 6 days, the flavor quality of the fermented black tea reaches the best, and the comprehensive score is 92.05.

TABLE 1 sensory evaluation of Eimeria-Stokes basket-fermented Black tea at different fermentation times

In addition, 6 days of best flavor fermented Eimeria fermented black tea (Ta) and control black tea 1-3 (YC, ZR, MJ) in the comparative example were selected for sensory scoring.

As shown in fig. 2 and table 2, the total score of the fermented tea of the eimeria stokes basket is 91.85, which proves that the fermented tea of the eimeria stokes basket can effectively reduce the astringency of the original tea sample, endow the tea with special fungus aroma and taste and improve the tea quality.

TABLE 2 sensory evaluation of Elmatoxylum schinifolium fermented tea and control Black tea

Experimental example 2: electronic tongue analysis of fermented tea of Emi stokes basket with different fermentation times

(1) Experimental method

1) Sample treatment: 3g of tea leaves (example, the fermented tea of the Acidovorax striatum under different fermentation time) are taken, and soaked in 150mL of boiling water for 5min, filtered by gauze, and tested by a machine after the tea soup is restored to room temperature.

2) Analysis conditions: before beginning the sample injection, the electronic tongue needs to be subjected to sensor activation, calibration and diagnosis. The time required to collect a tea sample is 30 seconds during analysis and one data is collected every second. Four repeated tests are carried out on each tea soup sample, and the stable measurement data of 3 times after selection are subjected to subsequent analysis, wherein the environment temperature range of the test is (25+/-2) DEG C.

(2) Experimental results

As shown in fig. 3, all taste indices of the six tea samples, except for the sourness and astringency below the taste threshold, exceeded the threshold, and were considered as effective taste indices. Overall, the trend of fermented black tea varies in a trend related to the number of days. Compared with 0d, the sweet taste, the delicate flavor and the bitter taste of the fermented tea of the Equisetum arvense for 3-15d are all increased, and the astringency, the astringency aftertaste and the bitter aftertaste are all reduced.

In addition, 6 days of fermentation of the best flavor of the Eimeria stenotrophomonas fermented black tea (Ta) and the control black tea 1-3 (YC, ZR, MJ) in the comparative example were selected for electronic tongue analysis.

As shown in fig. 4, the sweetness of the fermented tea of eimeria stokes basket was improved compared to the three control black teas. Compared with YC, the flavor of the fermented tea of the Eimeria stokes basket is improved. Therefore, the tea prepared by the method has delicious and fresh taste and sweet mellow taste, and better flavor quality than the original black tea.

Experimental example 3: development reason for flavor quality of fermented tea of Elmatoxylum eskii based on broad targeting metabonomics

1. Experimental method

1.1 Extraction of dry samples

Vacuum freeze-drying biological sample (fermented black tea Ta of Eimeria in 6 days, reference black tea YC, ZR, MJ), and grinding into powder; 50mg of the ground sample powder was taken and 1200. Mu.L of 70% aqueous methanol pre-chilled at-20℃as an internal standard extract was added. Vortex 6 times, once every 30 minutes, each for 30 seconds. Then centrifuging at 12000rpm for 3 min, collecting supernatant, filtering with 0.22 μm microporous membrane, and storing the filtered sample in sample bottle for subsequent ultra-high performance liquid chromatography-tandem mass spectrometry (ultra performance liquid chromatographytandem mass spectrometry, UPLC-MS/MS).

1.2, Chromatographic Mass Spectrometry acquisition conditions

(1) Liquid phase conditions:

Agilent SB-C18 column (2.1 mm. Times.100 mm,1.8 μm); mobile phase: the phase A is ultrapure water (containing 0.1% of formic acid by volume), the phase B is acetonitrile (containing 0.1% of formic acid by volume), and the elution gradient is 0-9 min and 5% of B; 9-10 min,95% B; 10-14 min,5% B; the flow rate is 0.35mL/min; column temperature is 40 ℃; the sample loading was 2. Mu.L.

(2) Mass spectrometry conditions:

The electrospray ion source (electrospray ionization, ESI) operating parameters were: the temperature is 550 ℃; an ion spray voltage (IS) 5500V (positive ion mode)/-4500V (negative ion mode); the ion source gas I (GSI), gas II (GSII), and gas curtain gas (CUR) were set at 50, 60, and 25psi, respectively, and the parameters of impact induced ionization were also set high. QQQ scanning adopts MRM mode, and the collision gas (nitrogen) is set to be medium. Meanwhile, by further optimizing the declustering voltage (declustering potential, DP) and Collision Energy (CE), DP and CE of each MRM ion pair are completed. During analysis, a specific set of MRM ion pairs was monitored based on the metabolites eluted during each period.

1.3 Data processing

Qualitative analysis was performed based on MWDB (metware database) database, which performs substance characterization based on secondary spectral information, and during analysis, isotope signals were removed, repeated signals containing k+ ions, na+ ions, nh4+ ions, and repeated signals of fragment ions, which are themselves other higher molecular weight substances. Meanwhile, a triple quadrupole mass spectrometry multiple reaction monitoring mode (multiple reaction monitoring, MRM) was used for quantitative analysis. After data is obtained from mass spectrometry of metabolites from different samples, peak alignment, peak matching correction, etc. are performed on the collected spectra, and the results are converted into compound retention time and peak area information.

2. Experimental results

2.1 Detection of total non-volatile metabolites of Eimeria-Stokes basket-like fermented tea and control Black tea

As can be seen from fig. 5, 1146 and 920 metabolites were detected in both positive and negative ion modes, respectively, and can be classified into 13 classes including flavonoids, amino acids and derivatives thereof, phenolic acids, alkaloids, esters, terpenoids, nucleotides and derivatives thereof, lignans and coumarins, organic acids, quinone compounds, steroids, tannins and other classes.

2.2 Principal component analysis and Cluster analysis of Eimeria-Stokes basket-like fermented tea and control Black tea

(1) And (3) principal component analysis: as shown in fig. 6 (a), the first principal component can explain 45.14% of the features of the original dataset, and the second principal component can explain 24.36% of the features of the original dataset, indicating that the experimental data has higher accuracy and repeatability. The different processing methods show that the different processing methods result in obvious changes of non-volatile metabolites in the Inulae-red nine black tea and small differences in groups.

(2) And (3) cluster analysis: from the cluster heat map of fig. 6 (b), YC and ZR are grouped into one class, and MJ and Ta are grouped into one class, indicating that the sterilization fermentation treatment and the non-sterilization fermentation treatment have significant effects on the non-volatile components of the tea. The MJ and Ta still have certain difference, and the fermentation of the inoculated Eimeria algocradle is proved to change the nonvolatile metabolites of the tea.

2.3 Differential metabolite overview of Eimeria-Stokes fermented tea and control Black tea

The differential metabolite is determined according to VIP value not less than 1 and FC value not less than 2 or not more than 0.5. 570 different substances are screened out according to the screening conditions, as shown in figure 7, wherein the phenolic acids (106), flavonoids (91) and amino acids and derivatives thereof (78) have the largest number of different metabolites, and the alkaloid (64), other classes (53), esters (49) and terpenoids (33) are the next.

2.4 Differential metabolite analysis of Eimeria-Stokes fermented tea and control Black tea

(1) Ta vsYC: as can be seen from fig. 8 (a), 462 differential metabolites were screened in total in Ta versus YC, including 245 up-regulated differential metabolites and 217 down-regulated differential metabolites, respectively. Among the down-regulated metabolites, 12 different metabolites have a taste, most are amino acids with bitter taste and derivatives and alkaloids thereof, such as L-tyrosine (threshold: 907.5), L-arginine (131000), L-lysine (threshold: 12430), L-histidine (threshold: 7370), theophylline (threshold: 135), tryptamine (threshold: 360), benzamide (threshold: 109), and the like. 7 substances in the up-regulated differential metabolites have sweet taste, mainly phenolic substances and saccharides in other classes, such as 2-phenethyl alcohol (threshold: d 0.045), 4-hydroxybenzoic acid (threshold: more than 13800), galactitol (threshold: 11285) and the like.

(2) Ta vs ZR: FIG. 8 (b) shows that 332 differential metabolites, including 134 up-regulated differential metabolites and 198 down-regulated differential metabolites, were screened in total in Ta versus ZR. Wherein 6 of the down-regulated differential metabolites have special taste, and 9 of the up-regulated differential metabolites have special taste.

(3) Ta vs MJ: in comparison of Ta and MJ, the differential metabolites were screened, and as shown in FIG. 8 (c), 112 differential metabolites were identified in total, 46 metabolites with lower Ta content and 66 metabolites with higher Ta content compared to MJ. Wherein, only resorcinol has bitter taste in the metabolites with low content, and the other metabolites have no special taste. Four different metabolites exist in the higher content of metabolites, including the sweet taste difference metabolite galactitol (threshold: 11285) and D-mannitol (threshold: 7280), the bitter taste difference metabolite pyrrole-2-carboxylic acid (threshold: 4440) and naringenin-7-O-neohesperidin (threshold: 72).

(4) The fermented tea mainly increases the sweet taste of tea soup and improves the quality of tea by increasing the contents of phenolic acid substances and sugar substances in other substances, such as 2-phenethyl alcohol (threshold: D0.045), 4-hydroxybenzoic acid (threshold: more than 13800), galactitol (threshold: 11285) and D-mannitol (threshold: 7280).

In conclusion, the method can convert amino acid and derivative substances thereof which cause bitter taste of tea leaves, and improve the contents of phenolic acids and sugar substances with sweet taste, thereby improving the problem that the summer black tea has strong bitter taste, and leading the prepared fermented tea to have special fungus fragrance and stronger fragrance than the summer black tea; the color of the tea soup is deeper than that of summer black tea, and the taste is more mellow and sweet than that of summer black tea. In addition, the tea making process provided by the invention takes tea leaves as a culture medium for growth of the Aim stokes basket bacteria on the premise of not adding any culture auxiliary materials, and the whole process has no external pollutants, so that the safety of products is ensured, and the popularization and application of summer tea are facilitated.

The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, and yet fall within the scope of the invention.

Claims (9)

1. A preparation method of an Ammonia-stokes basket-shaped fermented tea is characterized in that summer black tea is used as a raw material, amammonia-stokes basket-shaped bacteria are inoculated on tea to perform solid state fermentation, and the Amammonia-stokes basket-shaped fermented tea is obtained after drying.

2. The method for preparing the fermented tea of the eimeria stokes basket bacteria according to claim 1, wherein after sterilizing summer black tea, spore suspension of the eimeria stokes basket bacteria and sterile water are added, the tea is placed in an incubator after being sealed, fermented and cultured for 3 to 15 days at 28 to 32 ℃ and 80 to 90 percent of humidity, and finally the tea is obtained after drying.

3. The method for preparing fermented tea of eimeria stokes basket according to claim 2, wherein the eimeria stokes basket is purchased from the China center for type culture collection, and the strain number is: 15150000000; the strain deposit number is: CCTCCAF2021087.

4. The method for preparing the fermented tea of the eimeria stokes basket bacteria according to claim 2, wherein the method for preparing the summer black tea is as follows: withering black tea young shoots picked in summer for 14-18 hours at room temperature, and twisting for 1-3 hours; fermenting at 28-30deg.C and 85-90% humidity for 5-9 hr, and drying.

5. The method for preparing fermented tea of eimeria stokes basket according to claim 2, wherein the time of fermentation culture is 3-6 days.

6. The method for preparing fermented tea of eimeria stokes basket according to claim 2, wherein the concentration of the spore suspension is 1.0-0.5 x 10 ⁷ CFU/mL.

7. A process for the preparation of fermented tea of eimeria stokes basket as claimed in claim 2 wherein the ratio of black tea, spore suspension and sterile water is 50-70g:2-4mL:10-15mL.

8. A process for the preparation of fermented tea of eimeria stokes basket as claimed in claim 4 wherein the black tea comprises imperial red nine black tea.

9. A method of preparing fermented tea of eimeria stokes basket according to claim 2 wherein the spore suspension is made from spores produced by eimeria stokes basket passaged to the second generation.