TW202034778A - Process for preparing a flavor-improving tea materials and products prepared therefrom - Google Patents

Abstract

Disclosed herein is a process for preparing a fermentation product, comprising: fermenting the tea material with the strains ofBifidobacterium spp. and/orKluyveromyces spp.

Description

Method for preparing a fermentation product and the prepared fermentation product

The present invention relates to a method for preparing a fermentation product and the obtained fermentation product. The present invention also relates to a food product containing the fermentation product.

Tea is the most popular drink in the world. It contains vitamins, amino acids, alkaloids, tea polyphenols, minerals and other nutrients. It also refreshes, relieves fatigue, and Promote metabolism and equivalent effect. With the improvement of people's health awareness and living standards, consumers have higher and higher requirements for the quality of tea, not only considering the nutritional value of tea, but also paying great attention to the flavor of tea.

Traditionally, different degrees of enzymatic oxidation (also known as fermentation) are used to produce tea with different flavors, including black tea leaves, green tea leaves, etc. In recent years, researchers in the technical field have tried to improve the flavor of the tea by further microbial fermentation. For example, CN 105558139 A discloses a method for preparing health-care black tea, which includes sequential screening, withering and rolling of tea leaves, and then using a method containing Aspergillus niger and Penicillium . And high-protein Candida utilis ( Candida utilis ) bacteria liquid for fermentation, and then dried to enhance flavor. The tea leaves of health black tea with fruit aroma obtained by this method were found to have better flavor through sensory evaluation.

KR 100975199 B1 discloses a fermented green tea and a preparation method thereof by using Saccharomyces cerevisiae , Lactobacillus casei , Bacillus subtilis or Lactobacillus bulgaricus . Ferment the tea leaves. The fermented green tea obtained by this method was found to have a unique flavor and aroma through sensory evaluation.

Although there have been the aforementioned patent precedents, relevant researchers in the field are still committed to developing methods that can effectively enhance the flavor of tea. After research, the applicant unexpectedly found that using Bifidobacterium spp. and Kluyveromyces spp. to ferment tea can effectively enhance the flavor of tea.

Summary of the invention

Therefore, in the first aspect, the present invention provides a method for preparing a fermentation product, which comprises: fermenting a tea material with a strain of Bifidobacterium and/or Kluyveromyces species.

In the second aspect, the present invention provides a fermentation product, which is prepared by using a method as described above.

In the third aspect, the present invention provides a tea extract, which is prepared by extracting a fermentation product as described above using water.

In a fourth aspect, the present invention provides a food product, which contains a fermentation product and/or tea extract as described above.

Detailed description of the invention

It should be understood that if any previous case publication is quoted here, the previous case publication does not constitute a recognition: in Taiwan or any other country, the previous case publication forms a common general in the art Part of knowledge.

For the purpose of this specification, it will be clearly understood that the word "comprising" means "including but not limited to", and the word "comprises" has a corresponding meaning.

Unless otherwise defined, all technical and scientific terms used in this article have meanings commonly understood by those familiar with the art of the present invention. A person familiar with the art will recognize many methods and materials similar or equivalent to those described herein that can be used to implement the present invention. Of course, the present invention is by no means limited by the methods and materials described.

In order to develop a method that can enhance the flavor of tea, the applicant tried to select various strains of lactic acid bacteria and yeast strains to ferment the tea, and then use the obtained microbial fermented tea leaf to make tea. Of reviews. The evaluation results found that the use of Bifidobacterium spp. and Kluyveromyces spp. to ferment tea can effectively enhance the flavor of tea. Therefore, the present invention provides a method for preparing a fermentation product, which includes: using a strain of Bifidobacterium and/or Kluyveromyces species to perform processing on a tea material (fermentation product) Ferment.

According to the present invention, the tea material can be unprocessed (that is, freshly picked), partially-processed (partially-processed), or fully-processed. Leaves, buds or stems from tea plants, or by-products in processing, including tea residues, tea fannings, and tea powders (tea dust), pruned tea leaves and stem (pruned tea leaves and stem), sub-quality tea, and combinations thereof.

According to the present invention, the tea crops include, but are not limited to: tea tree ( Camellia sinensis ), camellia ( Camellia japonica ) and Alishan tea ( Camellia transarisanensis ).

Preferably, the tea crop is a cultivar selected from the group consisting of: Chin Shin Dah Pan (Chin Shin Dah Pan), Chin Shin Oolong (Chin Shin Oolong), Taiwan Tea No. 1 (TTES No. 1), Tai Cha No. 12 (TTES No. 12), Tai Tea No. 17 (TTES No. 17), Tai Tea No. 21 (TTES No. 21), Narcissus (Shoei Shian), Wuyi ( Bohea), Four Seasons Spring (Shy Jih Chuen), and their combinations. In a preferred embodiment of the present invention, the tea plant is Taicha No. 12.

According to the present invention, the processing treatment includes, but is not limited to: daylight withering treatment, indoor withering treatment, stirring treatment, rolling treatment, enzyme oxidation treatment and drying treatment.

Preferably, the tea material is tea leaves selected from the group consisting of black tea leaves, green tea leaves, yellow tea leaves, white tea leaves, green tea leaves, black tea leaves, and combinations thereof. In a preferred embodiment of the present invention, the tea material is black tea leaves. In another preferred embodiment of the present invention, the tea material is green tea leaves.

According to the present invention, the tea material has a water content ranging from 40% (w/w) to 70% (w/w) before the fermentation. According to the present invention, the water content of the tea material can be adjusted by rehydration treatment or drying treatment. In a preferred embodiment of the present invention, before the fermentation, the tea material is rehydrated to have a water content of 50% (w/w).

According to the present invention, the strains of Bifidobacterium species suitable for the present invention include, but are not limited to, strains derived from the following: Bifidobacterium bifidum , Bifidobacterium longum , Bifidobacterium infantis ( Bifidobacterium infantis ), Bifidobacterium breve ( Bifidobacterium breve ), Bifidobacterium adolescentis ( Bifidobacterium adolescentis ), Bifidobacterium lactis ( Bifidobacterium lactis ), Bifidobacterium boum ( Bifidobacterium boum ), pseudolong Bifidobacterium pseudolongum ( Bifidobacterium pseudolongum ), and their combinations. In a preferred embodiment of the present invention, the Bifidobacterium species is Bifidobacterium bifidus.

According to the present invention, strains of Kluyveromyces species suitable for the present invention include, but are not limited to, strains derived from the following strains: Kluyveromyces marxianus, Kluyveromyces lactis ( Kluyveromyces lactis), Kluyveromyces fragilis (Kluyveromyces fragilis), Kluyveromyces aestuarii, Kluyveromyces africanus, Kluyveromyces bacillisporus, Kluyveromyces blattae, Kluyveromyces dobzhanskii, Kluyveromyces yarrowii, Kluyveromyces lodderae, Kluyveromyces hubeiensis, Kluyveromyces nonfermentans, Kluyveromyces piceae, Kluyveromyces sinensis, Kluyveromyces thermotolerans , Kluyveromyces waltii , Kluyveromyces wickerhamii , and their combinations. In a preferred embodiment of the present invention, the Kluyveromyces species is Kluyveromyces marxianus.

As used herein, the terms "fermentation", "culturing" and "cultivation" can be used interchangeably. The operating procedures and parameter conditions related to fermentation fall within the scope of professionalism and routine technology of those who are familiar with this technology. In this regard, refer to, for example, CN 105558139 A and KR 100975199 B1.

It can be understood that the operating conditions related to the fermentation will be further changed with the strain used and the ratio of the amount of the strain to the tea material and other factors to achieve the best fermentation effect. The choice of these operating conditions is routinely determined by those who are familiar with the art.

According to the present invention, the weight ratio of the strain to the tea material is between 1:10 and 1:3000. In a preferred embodiment of the present invention, the weight ratio of the strain to the tea material is 1:30.

According to the present invention, when the strain is a Bifidobacterium species, the fermentation is performed at a temperature in the range of 30°C to 40°C for 4 hours to 72 hours. In a preferred embodiment of the present invention, the fermentation is carried out at 37°C for 48 hours.

According to the present invention, when the strain is a Kluyveromyces species, the fermentation is carried out at a temperature in the range of 20°C to 40°C for 2 hours to 72 hours. In a preferred embodiment of the present invention, the fermentation is carried out at 25°C for 48 hours.

The present invention also provides a fermentation product, which is prepared by using a method as described above.

In addition, the present invention provides a tea extract, which is prepared by using water to extract a fermentation product as described above.

According to the present invention, the extraction can be carried out using a technique well-known and commonly used by those skilled in the art.

It can be understood that the extraction operating conditions will be further changed with factors such as the amount ratio of the fermentation product to water in order to achieve the best extraction effect. The choice of these operating conditions is routinely determined by those who are familiar with the art.

According to the present invention, the fermented product and the tea extract can be used as a food additive, which is added during the preparation of raw materials by a conventional method, or added during the production of food, and can be combined with either Edible materials are formulated into food products for human and non-human animals to eat.

Therefore, the present invention also provides a food product, which contains a fermentation product and/or tea extract as described above.

According to the present invention, the types of food products include, but are not limited to: beverages, baked foods, confectionery, ice cream, dairy products, spreads , Seasoning, fermented food, animal feeds, health foods and dietary supplements.

Detailed description of the preferred embodiment

The present invention will be further described with the following embodiments, but it should be understood that these embodiments are only for illustrative purposes and should not be interpreted as limitations on the implementation of the present invention. Examples General experimental materials: 1. The lactic acid bacteria strains and yeast strains used in the following examples are obtained from the Biological Resources Conservation and Research Center of the Food Industry Research and Development Institute (FIRDI) in Taiwan (Bioresource Collection and Research Center, BCRC) (No. 331, Food Road, Hsinchu City, Taiwan), and have been integrated in Table 1 and Table 2 below. Table 1. Various strains of lactic acid bacteria Strain Lactobacillus ( Lactobacillus ) Lactobacillus paracasei BCRC 12248 Lactobacillus casei BCRC 10697 Lactobacillus brevis BCRC 10696 Lactobacillus rhamnosus BCRC 10940 Lactobacillus delbrueckii BCRC 12256 Lactobacillus acidophilus BCRC 10695 Lactobacillus fermentum BCRC 12190 Lactobacillus gasseri BCRC 14619 Lactococcus ( Lactococcus ) Lactococcus lactis BCRC 12312 Streptococcus ( Streptococcus ) Streptococcus salivarius subsp. thermophilus BCRC 13869 Sporolactobacillus ( Sporolactobacillus ) Sporolactobacillus inulinus BCRC 14647 Bifidobacterium ( Bifidobacterium ) Bifidobacterium bifidum BCRC 14670 Bifidobacterium longum BCRC 11847 Table 2. Various yeast strains Strain Candida ( Candida ) Candida utilis BCRC 21990 Kluyveromyces ( Kluyveromyces ) Kluyveromyces marxianus BCRC 21480 Kluyveromyces marxianus BCRC 21698 Kluyveromyces marxianus BCRC 21695 Kluyveromyces marxianus BCRC 23198 Kluyveromyces marxianus BCRC 28042 Saccharomyces ( Saccharomyces ) Saccharomyces cerevisiae BCRC 21447 Saccharomyces cerevisiae BCRC 21469 Saccharomyces cerevisiae BCRC 23068 Saccharomyces cerevisiae BCRC 23144 Saccharomyces cerevisiae BCRC 23414 2. The MRS medium used in the following examples has the formula shown in Table 3 below. Table 3. Formula of MRS medium ingredient Concentration (%) (w/v) glucose 2 Yeast extract 0.5 Meat extract 1 Egg White 1 Di-ammonium hydrogen citrate 0.2 Sodium acetate 0.5 K ₂ HPO ₄ 0.2 MgSO ₄ ‧7H ₂ O 0.058 MnSO ₄ ‧4H ₂ O 0.025 The balance is deionized water 3. The YM medium used in the following examples has the formula shown in Table 4 below. Table 4. Formula of YM medium ingredient Concentration (%) (w/v) Dextrose 1 Yeast extract 0.3 Malt extract 0.3 Egg White 0.5 The balance is deionized water 4. The green tea leaves and black tea leaves used in the following examples are from Taicha No. 12 from the Tea Industry Improvement Plant, and before fermentation, sterile water is used for rehydration treatment to make It has a water content of 50% (w/w). General experimental methods: 1. Tea leaf tasting:

Take 3 g of each tea to be evaluated and soak it in 150 mL of boiling water for 5 minutes, and then provide the tea to the taster for drinking, and the taster will evaluate their flavor after drinking. It is scored and expressed on a scale of 1 to 100. The higher the value, the better the flavor. Example 1. Screening strain A that can enhance the flavor of microbial fermented tea leaf , using lactic acid bacteria strains and yeast strains to ferment green tea leaves:

First, the 13 lactic acid bacteria strains described in item 1 of the above "General Experimental Materials" were respectively inoculated into the MRS medium shown in Table 3 above, and then cultured at 37°C for 48 hours, and the above The 11 yeast strains described in item 1 of "General Experimental Materials" were respectively inoculated into YM medium as shown in Table 4 above, and then cultured at 25°C for 48 hours to activate the strains. Next, the formed culture of each strain was centrifuged at 8000 rpm for 5 minutes, then the cell pellet was collected and washed with sterile water once, and then centrifuged at 8000 rpm for 5 minutes to remove the supernatant and Collect the bacteria of each strain. After that, 1 g of each of the bacterial cells of each strain was taken and dissolved in 3 mL of sterile water respectively, thereby obtaining inoculation sources (inoculum) of the 13 lactic acid bacteria strains and the 11 yeast strains.

Finally, the inoculation source of each lactic acid bacteria strain was inoculated into 30 g of rehydrated green tea leaves with an inoculum of 3 mL, and then fermented and cultivated at 37°C for 48 hours, and then dried with hot air. And 13 kinds of lactic acid bacteria fermented green tea leaf were obtained.

In addition, the inoculation source of each yeast strain was inoculated into 30 g of rehydrated green tea leaves with an inoculum amount of 3 mL, and then fermented and cultured at 25°C for 48 hours, and then dried with hot air. Thus, 11 kinds of yeast fermented green tea leaves were obtained.

Afterwards, the obtained green tea leaves that were fermented by microorganisms were evaluated according to the method described in item 1 of the "General Experimental Methods" above, and the green tea leaves before rehydration were used as the control group. The evaluation results are shown in Table 5 and Table 6 below. Table 5. The flavor of tea leaves fermented by various lactic acid bacteria strains Strain Flavor Lactobacillus Lactobacillus paracasei BCRC 12248 62.5 Lactobacillus casei BCRC 10697 70.0 Lactobacillus brevis BCRC 10696 65.0 Lactobacillus rhamnosus BCRC 10940 42.5 Lactobacillus debaisi BCRC 12256 62.5 Lactobacillus acidophilus BCRC 10695 65.0 Lactobacillus fermentum BCRC 12190 67.5 Lactobacillus gasseri BCRC 14619 70.0 Lactococcus Lactococcus lactis BCRC 12312 70.0 Streptococcus Streptococcus salivarius subsp. thermophilus BCRC 13869 55.0 Sporolactobacillus Lactobacillus inulinus BCRC 14647 50.0 Bifidobacterium Bifidobacterium bifidus BCRC 14670 82.5 Bifidobacterium longum BCRC 11847 72.5 Control group 65.0

It can be seen from Table 5 that when lactic acid bacteria are used to ferment green tea leaves, lactobacilli may not necessarily enhance the flavor of green tea leaves, and may even reduce the flavor, while streptococcus and spore lactobacilli will reduce the flavor of green tea leaves. Relatively, Both Bifidobacterium and Lactococcus can enhance the flavor of green tea leaves. In particular, the flavor of green tea leaves fermented by various Bifidobacterium strains is better than that of each Lactobacillus strain. Table 6. Flavors of tea leaves fermented by various yeast strains Strain Flavor Candida Candida high protein BCRC 21990 67.5 Kluyveromyces Kluyveromyces marxianus BCRC 21480 75.0 Kluyveromyces marxianus BCRC 21698 84.5 Kluyveromyces marxianus BCRC 21695 94.5 Kluyveromyces marxianus BCRC 23198 98.0 Kluyveromyces marxianus BCRC 28042 94.0 Fermentum Brewing mother bacteria BCRC 21447 72.5 Brewing mother bacteria BCRC 21469 62.5 Brewing mother bacteria BCRC 23068 62.5 Brewing mother bacteria BCRC 23144 57.5 Brewing mother bacteria BCRC 23414 60.0 Control group 67.5

It can be seen from Table 6 that when yeast is used to ferment green tea leaves, the fermenting mother fungus may not necessarily enhance the flavor of green tea leaves, and may even reduce the flavor, while Candida cannot enhance the flavor of green tea leaves. Relatively, Kluyveromyces can enhance the flavor of green tea leaves. In particular, the flavor of green tea leaves fermented by each strain of Kluyveromyces is better than that of each strain of fermenting mother. B. Use lactic acid bacteria strains and yeast strains to ferment black tea leaves:

This experiment is basically carried out with reference to the method described in item A above. The difference is that black tea leaves are used instead of green tea leaves, and Lactobacillus rhamnosus BCRC 10940 and Lactobacillus gasseri BCRC are selected among the lactic acid bacteria strains. 14619, Lactococcus lactis BCRC 12312, Streptococcus salivarius subsp. thermophilus BCRC 13869, Bacillus inulinus BCRC 14647 and Bifidobacterium bifidus BCRC 14670 as representatives, and high-protein Candida strains among the yeast strain BCRC 21990, Kluyveromyces marxianus BCRC 21480, BCRC 21698, BCRC 21695, BCRC 23198 and BCRC 28042, and brewing mother bacteria BCRC 21447 and BCRC 23414 are representative. The evaluation results are shown in Table 7 and Table 8 below. Table 7. Flavor of tea leaves fermented by various lactic acid bacteria strains Strain Flavor Lactobacillus Lactobacillus rhamnosus BCRC 10940 55.0 Lactobacillus gasseri BCRC 14619 65.0 Lactococcus Lactococcus lactis BCRC 12312 65.0 Streptococcus Streptococcus salivarius subsp. thermophilus BCRC 13869 56.3 Sporolactobacillus Lactobacillus inulinus BCRC 14647 42.5 Bifidobacterium Bifidobacterium bifidus BCRC 14670 67.5 Control group 57.5

It can be seen from Table 7 that when lactic acid bacteria are used to ferment black tea leaves, lactobacilli may not necessarily enhance the flavor of black tea leaves, and may even reduce the flavor, while streptococcus and spore lactobacillus both reduce the flavor of black tea leaves. Relatively, Both Bifidobacterium and Lactococcus can enhance the flavor of black tea leaves. In particular, the flavor of black tea leaves fermented by bifidobacterium strains is better than that of each Lactobacillus strain. Table 8. The flavor of tea leaves fermented by various yeast strains Strain Flavor Candida Candida high protein BCRC 21990 45.0 Kluyveromyces Kluyveromyces marxianus BCRC 21480 92.5 Kluyveromyces marxianus BCRC 21698 79.3 Kluyveromyces marxianus BCRC 21695 78.1 Kluyveromyces marxianus BCRC 23198 84.3 Kluyveromyces marxianus BCRC 28042 95.0 Fermentum Brewing mother bacteria BCRC 21447 62.5 Brewing mother bacteria BCRC 23414 45.0 Control group 60.0

It can be seen from Table 8 that when yeast is used to ferment black tea leaves, the brewing mother fungus may not necessarily enhance the flavor of black tea leaves, and may even reduce the flavor, while Candida cannot enhance the flavor of black tea leaves. Relatively, Kluyveromyces can enhance the flavor of black tea leaves. In particular, the flavor of black tea leaves fermented by each strain of Kluyveromyces is better than that of each strain of fermenting mother.

In addition, it can be observed that each strain has the same tendency to affect the flavor of black tea leaves and green tea leaves.

Based on the above experimental results, the applicant believes that the use of Bifidobacterium spp. and Kluyveromyces spp. to ferment tea can effectively enhance the flavor of tea. Headspace embodiment of the invention by microbial fermentation of tea 2. This embodiment - Solid Phase Microextraction - gas chromatography - mass spectrometry (headspace-solid phase microextraction-gas chromatography-mass spectrometry, HS-SPME-GC-MS) analysis

In order to investigate the influence of the microbial fermentation of the present invention on the flavor of tea from a chemical level, the black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 obtained in Example 1 above were used for headspace-solid phase microextraction. -Gas chromatography-mass spectrometry analysis to detect the content of grassy odor and aromatic odor odor molecules. experimental method:

The HS-SPME-GC-MS analysis is carried out with reference to the method described in Lin Shuyan et al. (2012), Research Report of Taiwan Tea Industry, 31:85-98, with some modifications. In short, 0.1 g of black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 obtained in Example 1 above were placed in a closed container, and then a solid phase microextraction fiber was used. [50/30 μm, divinylbenzene (DVB)/Carboxen ^® )/polydimethylsiloxane (PDMS) fiber] (Supelco) and headspace-solid phase at 50℃ Microextraction (headspace-solid phase microextraction) lasted 15 minutes, so that the volatile organic compounds (VOCs) in the tea were adsorbed on the solid phase microextraction fiber, and then gas chromatography-mass spectrometry was used ( gas chromatography-mass spectrometry, GC-MS) to analyze the collected volatile organic compounds. The GC-MS analytical instruments used in this experiment are as follows: Hewlett Packard Agilent 5890 Series II; detection system is Hewlett Packard Agilent 5975B MSD; analytical column is HP-5MS capillary column, which has a length of 30 m and a The inner diameter is 0.25 mm, and a film with a thickness of 0.25 μm is used. The GC-MS operating conditions are shown in Table 9 below. Table 9. Operating conditions of gas chromatography-mass spectrometry Operating parameters condition Heating program of column oven Maintained at an initial temperature of 40°C for 3 minutes; then, the temperature was increased to 200°C (5°C/min), and maintained at 200°C for 5 minutes. Carrier gas Ultra-high purity helium (He) Carrier gas flow rate 8.9 mL/min Injector temperature 210°C Detector temperature 250°C The electron ionization mode (EI mode) of the mass spectrometer 70 eV

After that, the measured mass spectrum of each volatile organic compound was used to compare with the known indicator component of grassy flavor in Wiley and NIST mass spectral databases (including hexanal) , Trans-2-hexenal (trans-2-hexenal), cis-3-hexenol (cis-3-hexenol) and 1-hexenol (1-hexenol)) and aromatic indicators [Including 3-methylbutan-1-ol (3-methylbutan-1-ol), 2-methylpropyl ethanoate (2-methylpropyl ethanoate), 3-methyl butyl acetate (3-methyl butyl acetate) ), 2-methyl butyl acetate (2-methyl butyl acetate), benzyl acetate (benzyl acetate) and 2-phenylethyl acetate (2-phenylethyl acetate) mass spectra for comparison, in order to identify the The types of odor molecules contained, and further estimate the content (%) of these odor molecules based on their peak areas.

In addition, the applicant used the black tea leaves before rehydration as a control group and performed the same experiment. result:

Figure 1 shows the measured content of grassy odor molecules in black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 of the present invention. As can be seen from Figure 1, compared with the control group, the black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 contain hexanal, trans-2-hexenal, and cis-3- Both hexenol and 1-hexenol are significantly reduced.

Figure 2 shows the content of aromatic odor molecules measured in black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 of the present invention. It can be seen from Figure 2 that compared with the control group, the 3-methylbutan-1-ol and 2-methylpropane acetate contained in the black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 of the present invention Ester, 3-methylbutyl acetate, 2-methylbutyl acetate, benzyl acetate and 2-phenylethyl acetate all increased significantly.

These experimental results show that the microbial fermentation of the present invention may increase the flavor of tea leaves due to the reduction of grassy odor molecules and the production of aromatic odor molecules, and the presence of these aromatic odor molecules will make it easier to drink. You can taste the aroma of fruits and flowers.

All patents and documents cited in this specification are incorporated into this case as reference materials in their entirety. If there is a conflict, the detailed description of the case (including definitions) will prevail.

Although the present invention has been described with reference to the above specific specific examples, it is obvious that many modifications and changes can be made without departing from the scope and spirit of the present invention. Therefore, it is intended that the present invention is only limited by the scope of the patent application attached hereto.

The above and other objects, features and advantages of the present invention will become apparent with reference to the following detailed description and preferred embodiments and the accompanying drawings, in which: Figure 1 shows the measured content of grassy odor molecules in black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 of the present invention; and Figure 2 shows the content of aromatic odor molecules measured in black tea leaves fermented by Kluyveromyces marxianus BCRC 28042 of the present invention.

Claims (13)

A method for preparing a fermentation product, which comprises: using Bifidobacterium spp. and/or Kluyveromyces spp. strains to ferment a tea material. The method of claim 1, wherein the tea material is tea leaves selected from the group consisting of black tea leaves, green tea leaves, yellow tea leaves, white tea leaves, green tea leaves, black tea leaves, and their combination. The method of claim 1, wherein the tea material has a water content ranging from 40% (w/w) to 70% (w/w) before the fermentation. Such as the method of claim 1, wherein the weight ratio of the strain to the tea material is between 1:10 and 1:3000. The method of claim 1, wherein when the strain is a Bifidobacterium species, the fermentation is performed at a temperature in a range of 30°C to 40°C for 4 hours to 72 hours. The method of claim 1, wherein when the strain is a Kluyveromyces species, the fermentation is performed at a temperature in a range of 20°C to 40°C for 2 hours to 72 hours. The method of claim 1, wherein the Bifidobacterium species is selected from the group consisting of Bifidobacterium bifidum ( Bifidobacterium bifidum ), Bifidobacterium longum , infantile bifidum Bifidobacterium infantis , Bifidobacterium breve , Bifidobacterium adolescentis , Bifidobacterium lactis , Bifidobacterium boum , Bifidobacterium boum , Bifidobacterium breve ( Bifidobacterium pseudolongum ), and their combinations. The method of claim 7, wherein the Bifidobacterium species is Bifidobacterium bifidus. The method of claim 1, wherein the Kluyveromyces species is selected from the group consisting of: Kluyveromyces marxianus ( Kluyveromyces marxianus), Kluyveromyces lactis ( Kluyveromyces lactis ) , Kluyveromyces fragilis (Kluyveromyces fragilis), Kluyveromyces aestuarii, Kluyveromyces africanus, Kluyveromyces bacillisporus, Kluyveromyces blattae, Kluyveromyces dobzhanskii, Kluyveromyces yarrowii, Kluyveromyces lodderae, Kluyveromyces hubeiensis, Kluyveromyces nonfermentans, Kluyveromyces piceae, Kluyveromyces sinensis, Kluyveromyces thermotolerans, Kluyveromyces waltii , Kluyveromyces wickerhamii , and their combinations. The method of claim 9, wherein the Kluyveromyces species is Kluyveromyces marxianus. A fermentation product prepared by using the method described in any one of claims 1 to 10. A tea extract prepared by using water to extract the fermentation product as in claim 11. A food product comprising a fermented product as claimed in claim 11 and/or a tea extract as claimed in claim 12.

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