Packed tea beverage with reduced gallate-type catechin, and method for producing the same

Abstract

To provide (i) a packed tea beverage with reduced gallate-type catechin, (ii) a method for producing tea extract with reduced gallate-type catechin, and (iii) a method for reducing astringency and browning in tea extract.SOLUTION: The present invention provides a packed tea beverage. In the packed tea beverage, the catechin level is 40 mg / 100 mL or less. In the packed tea beverage, the ratio of the gallate-type catechin level to the catechin level is less than 33%. In the packed tea beverage, the ratio of the catechin level to the tannin level is 70% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to (i) a packaged tea beverage with reduced gallated catechins, (ii) a method for producing a tea extract with reduced gallated catechins, and (iii) a method for reducing astringency and browning of a tea extract. [Background technology]

[0002] Tea beverages contain various components such as catechins. For example, green tea beverages extracted from green tea with an aqueous solvent contain useful components such as non-polymer catechins, caffeine, amino acids, and vitamin C. In particular, non-polymer catechins have attracted attention for their various health functionalities, such as antioxidant and antibacterial activities.

[0003] On the other hand, non-polymer catechins are components that exhibit astringent or astringent taste, and if the astringency is too strong, it can cause discomfort or aversion. Non-polymer catechins include free catechins (epigallocatechin, gallocatechin, epicatechin, and catechin) and gallate catechins (epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, and catechin gallate). Among non-polymer catechins, gallate catechins in particular have a problem in that they leave a strong astringent aftertaste, and from the perspective of drinkability, it is desirable to keep the astringent or astringent taste within a certain intensity. Another problem is that gallate catechins significantly contribute to browning of tea beverages over time, and from this perspective, it is also desirable to keep the concentration within a certain level.

[0004] Various methods are known for reducing the amount of gallated catechins in tea extracts. For example, Patent Document 1 discloses a method comprising treating a tea extract containing non-polymer catechins with tannase, the gallate content of which is 50% by mass or more, and contacting the tannase-treated tea extract with a synthetic adsorbent. However, this method involves the use of a synthetic adsorbent, which poses challenges in terms of safety and consumer acceptability. Patent Document 2 discloses a method comprising treating a green tea extract with tannase and adding sugars. However, this method involves the addition of sugars, which poses challenges, such as its inability to be used in, for example, sugar-free tea beverages. Patent Document 3 discloses a method for producing a green tea extract, which includes a step of contacting a raw green tea extract with used tea leaves. However, this method has challenges, such as the inability to sufficiently reduce the amount of gallated catechins in the green tea extract. Patent Document 4 discloses a method for producing a tea extract, which includes a step of contacting a raw tea extract with at least one protein selected from the group consisting of glutelin and gliadin. However, glutelin and gliadin are not widely used food ingredients, and this method has problems in terms of versatility, etc. Patent Document 5 also discloses a method in which tea leaf extract is contacted with polyvinylpolypyrrolidone (PVPP) to reduce the proportion of gallate-type catechins in the tea leaf extract to 30% or less of the total catechins. However, this method has problems such as a tendency to lack the characteristic tea flavor.

[0005] On the other hand, regarding the use of microorganisms in food and beverages, Patent Document 6 discloses a method for enhancing the depth and mellowness of the taste of food and beverages by adding yeast extract to the food and beverage, and Patent Document 7 discloses a method for improving the taste and tea leaf feel by adding yeast extract, linalool, and hexanoic acid to decaffeinated black tea, and adjusting the ratio of the hexanoic acid content to the linalool content to a specific range.In addition, Patent Document 8 discloses a method for suppressing the color deterioration of tea beverages during heat sterilization by adding lactic acid bacteria to tea beverages, and Patent Document 9 discloses a method for adjusting the pH of Lactobacillus pentosus and / or Lactobacillus plantarum-containing beverages to 5.7 or higher to suppress the sedimentation of these lactic acid bacteria. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-136703 [Patent Document 2] Japanese Patent Publication No. 2020-127375 [Patent Document 3] Japanese Patent Application Publication No. 2018-29566 [Patent Document 4] Japanese Patent Application Publication No. 2018-29567 [Patent Document 5] Japanese Patent Application Laid-Open No. 2004-159597 [Patent Document 6] Japanese Patent Application Laid-Open No. 2014-18098 [Patent Document 7] Japanese Patent Application Laid-Open No. 2018-153134 [Patent Document 8] Japanese Patent Publication No. 2022-145447 [Patent Document 9] Japanese Patent Application Publication No. 2019-62747 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide (i) a packaged tea beverage having reduced gallated catechins, (ii) a method for producing a tea extract having reduced gallated catechins, and (iii) a method for reducing the astringency and browning of a tea extract. [Means for solving the problem]

[0008] As a result of extensive research conducted by the present inventors to solve the problems of the present invention, (a) The catechin concentration in packaged tea beverages shall be 400 mg / L or less; The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and By setting the ratio of the catechin concentration to the tannin concentration in the packaged tea beverage to 70% or more, A packaged tea beverage with reduced astringency and browning can be obtained; and (b) A tea extract having reduced gallate-type catechins can be obtained by contacting a raw material tea extract with microbial cells, and the tea extract and a tea beverage containing the tea extract have reduced astringency and browning; The above findings led to the completion of the present invention.

[0009] That is, the present invention provides the following inventions. (1) A packaged tea beverage, The catechin concentration in the packaged tea beverage is 400 mg / L or less, The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and the packaged tea beverage containing a tea extract produced by a tea extract production method including a step A of contacting a raw material tea extract with microbial cells; (2) A packaged tea beverage, The catechin concentration in the packaged tea beverage is 400 mg / L or less, The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and the packaged tea beverage, wherein the ratio of the catechin concentration to the tannin concentration in the packaged tea beverage is 70% or more; (3) The packaged tea beverage according to (1) or (2) above, having a tannin concentration of 500 mg / L or less; (4) The packaged tea beverage according to any one of (1) to (3) above, in which the ratio of the concentration of gallated catechins to the concentration of caffeine is 30% or more and less than 100%; (5) The packaged tea beverage according to any one of (1) to (4) above, having a caffeine concentration of 150 mg / L or less; (6) A method for producing a tea extract, comprising step A of contacting a raw material tea extract with microbial cells; (7) The method according to (6) above, wherein the microbial cells are cells of one or more species selected from the group consisting of yeast and lactic acid bacteria; (8) The production method according to (6) above, which comprises, after step A, step B of removing the microbial cells obtained in step A; (9) A method for reducing astringency and browning of a tea extract, comprising step A of contacting a raw material tea extract with microbial cells; (10) The method according to (9) above, wherein the microbial cells are cells of one or more species selected from the group consisting of yeasts and lactic acid bacteria; [Effects of the Invention]

[0010] According to the present invention, it is possible to provide (i) a packaged tea beverage having reduced gallated catechins, (ii) a method for producing a tea extract having reduced gallated catechins, and (iii) a method for reducing the astringency and browning of a tea extract. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows the relationship between the Lactococcus lactis subsp. lactis JCM5805 strain and strains equivalent to this strain (strains derived from this strain and strains from which this strain is derived). DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention provides [1] A packaged tea beverage, The catechin concentration in the packaged tea beverage is 400 mg / L or less, The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and a packaged tea beverage containing a tea extract produced by a tea extract production method including step A of contacting a raw material tea extract with microbial cells (hereinafter also referred to as the "first beverage of the present invention"); [2] A packaged tea beverage, The catechin concentration in the packaged tea beverage is 400 mg / L or less, The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and The packaged tea beverage, in which the ratio of the catechin concentration to the tannin concentration in the packaged tea beverage is 70% or more (hereinafter also referred to as the "second beverage of the present invention"); (hereinafter the first beverage and second beverage of the present invention will be collectively referred to as the "beverage of the present invention"). [3] A method for producing a tea extract, comprising step A of contacting a raw material tea extract with microbial cells (hereinafter also referred to as the "production method of the present invention"); [4] A method for reducing astringency and browning in a tea extract, comprising step A of contacting a raw material tea extract with microbial cells (hereinafter also referred to as the "reduction method of the present invention"); The present invention includes embodiments such as:

[0013] (Drink of the present invention) The beverage of the present invention comprises: "A packaged tea beverage, The catechin concentration in the packaged tea beverage is 400 mg / L or less, The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and The packaged tea beverage containing a tea extract produced by a tea extract production method including step A of contacting a raw material tea extract with microbial cells (first beverage of the present invention), or "A packaged tea beverage, The catechin concentration in the packaged tea beverage is 400 mg / L or less, The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and The packaged tea beverage, wherein the ratio of the catechin concentration to the tannin concentration in the packaged tea beverage is 70% or more." (Second beverage of the present invention) is. In this specification, the concentrations of catechins, gallate-type catechins, tannins, etc. in a beverage refer to the concentrations in the liquid portion of the beverage, and in cases where the beverage contains solids such as microbial cells or ground tea leaves, they refer to the concentrations in the liquid after removing these solids.

[0014] (Catechin concentration) As used herein, "catechins" refers to one or more selected from the group consisting of catechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. Furthermore, "catechin concentration" refers to the total concentration of catechins in a beverage.

[0015] The concentration of catechins in the beverage of the present invention is not particularly limited, but may be, for example, 400 mg / L or less, and preferably 350 mg / L or less from the viewpoint of obtaining the maximum effect of the present invention. The concentration of catechins in a beverage can be measured and quantified by a method using high performance liquid chromatography (HPLC). The concentration of catechins in the beverage of the present invention can be adjusted, for example, by adjusting the amounts of tea leaves and water used when preparing the tea extract.

[0016] (Concentration of gallate-type catechins) "Gallate catechins" is a general term for four types of gallate catechins: epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, and catechin gallate. Furthermore, "concentration of gallate catechins" refers to the total concentration of gallate catechins in a beverage.

[0017] The concentration of gallated catechins in the beverage of the present invention is not particularly limited as long as the ratio of the concentration of gallated catechins to the concentration of catechins is less than 33%, but the concentration of gallated catechins in the beverage is, for example, 92 mg / L or less, and from the viewpoint of obtaining the maximum effect of the present invention, preferably 85 mg / L or less, 80 mg / L or less, or 75 mg / L or less.

[0018] The concentration of catechins in a beverage can be measured and quantified by a method using high-performance liquid chromatography (HPLC). The concentration of gallated catechins in the beverage of the present invention can be adjusted, for example, by adjusting the amounts of tea leaves and water used when preparing the tea extract, by performing tannase treatment, or by the amount of microbial cells brought into contact with the raw material tea extract.

[0019] (Ratio of gallate-type catechins to catechins) The ratio of the concentration of gallated catechins to the concentration of catechins in the beverage of the present invention is not particularly limited as long as it is less than 33%, but from the viewpoint of obtaining the effects of the present invention to the fullest extent, preferred examples include 31% or less, 30% or less, and 28% or less. Such a ratio can be adjusted by adjusting the concentration of catechins or the concentration of gallated catechins in the beverage of the present invention.

[0020] (tannin concentration) The tannin concentration in the beverage of the present invention is not particularly limited, but may be, for example, 800 mg / L or less, 600 mg / L or less, or 500 mg / L or less. The lower limit of the tannin concentration in the beverage of the present invention is not particularly limited, but may be, for example, 200 mg / L or more, or 300 mg / L or more. These upper and lower limit values ​​can be combined in any desired manner.

[0021] The tannin concentration in a beverage can be measured using the official method (ferrous tartrate absorbance method) described in "Commentary on the Japanese Standard Food Composition Analysis Manual, 5th Edition," edited by the Japan Food Research Laboratories (Chuohoki, July 2001, p. 252), which is the standard for evaluating the polyphenol content of teas. This measurement method involves measuring the absorbance (540 nm) of the purple component produced by reacting polyphenols in a liquid with an ferrous tartrate reagent, and quantitating the purple component using a calibration curve prepared using ethyl gallate as the standard. The tannin content can be determined by multiplying the quantified value thus obtained by 1.5. The tannin concentration in the beverage of the present invention can be adjusted, for example, by adjusting the amounts of tea leaves and water used when preparing the tea extract.

[0022] (Ratio of catechin concentration to tannin concentration) The ratio of catechin concentration to tannin concentration in the beverage of the present invention is not particularly limited, but may be, for example, 70% or more, preferably 72% or more. The upper limit of this ratio is also not particularly limited, but may be 92% or less, 90% or less, 85% or less, 81% or less, or 80% or less. This ratio can be adjusted by adjusting the catechin concentration or the concentration of gallate-type catechins in the beverage of the present invention. In the second beverage of the present invention, the ratio of catechin concentration to tannin concentration is 70% or more, preferably 72% or more. The upper limit of this ratio is, for example, as described above.

[0023] (Caffeine concentration) The caffeine concentration in the beverage of the present invention is not particularly limited, but examples include 150 mg / L or less, and 100 mg / L or less.

[0024] The caffeine concentration in a beverage can be measured and quantified by a method using high performance liquid chromatography (HPLC). The caffeine concentration in the beverage of the present invention can be adjusted, for example, by adjusting the amounts of tea leaves and water used when preparing the tea extract, or by selecting tea leaves with a predetermined caffeine concentration.

[0025] (Ratio of gallate-type catechin concentration to caffeine concentration) The ratio of the concentration of gallated catechins to the concentration of caffeine in the beverage of the present invention is not particularly limited, but from the viewpoint of obtaining the maximum effect of the present invention, it is preferably 30% or more but less than 100%, more preferably 30% or more but less than 95%, and even more preferably 30% or more but less than 90%. Such a ratio can be adjusted by adjusting the concentration of gallated catechins or the concentration of caffeine in the beverage of the present invention.

[0026] (tea drink) The beverage of the present invention is a tea beverage. The "tea beverage" in the present invention is not particularly limited, but examples thereof include unfermented tea (e.g., green tea) beverages, fermented tea (e.g., black tea) beverages, semi-fermented tea (e.g., oolong tea) beverages, and blended tea beverages of some or all of these, of which green tea beverages, oolong tea beverages, and black tea beverages are preferred, and green tea beverages and black tea beverages are more preferred, with green tea beverages being even more preferred.

[0027] Tea beverages contain tea extracts. In the present invention, "tea extract" refers to an extract obtained by subjecting tea leaves (including ground tea leaves such as matcha) to an extraction process. The tea extract may be in the form of a liquid or a solid such as a powder. The tea extract used in the present invention includes an extract from tea leaves (tea leaf extract) itself, processed products thereof (e.g., concentrated liquid extract, powder extract), or diluted solutions thereof. The tea extract is not particularly limited and can be appropriately selected from tea extract raw materials (preferably green tea extract raw materials, black tea extract raw materials, and / or oolong tea extract raw materials) conventionally used in the production of tea beverages. In the present specification, "tea extract" includes unfermented tea extracts (e.g., green tea extracts), fermented tea extracts (e.g., black tea extracts), and semi-fermented tea extracts (e.g., oolong tea extracts). Of these, green tea extracts, black tea extracts, and oolong tea extracts are preferred, with green tea extracts and black tea extracts being more preferred, and green tea extracts being even more preferred. In the present invention, the extraction treatment is sufficient as long as the tea components are dissolved in the extraction solvent, and includes, for example, treatments such as dissolving ground tea leaves such as matcha.

[0028] The tea leaves used to prepare the tea extract may be those belonging to the tea plant Camellia sinensis (Camellia sinensis var.), an evergreen tree of the Theaceae family. The tea leaves used to produce the tea beverage of the present invention are not particularly limited as long as they achieve the effects of the present invention. These include unfermented tea leaves, such as green tea, including sencha, gyokuro, matcha, kamairicha, fukamushicha, bancha, and hojicha, as well as semi-fermented tea leaves such as oolong tea and fermented tea leaves such as black tea. Green tea leaves and black tea leaves are preferred as tea leaves used in the present invention, with green tea leaves being more preferred. Multiple types of raw materials and tea leaves may also be used in the present invention.

[0029] The method for extracting tea leaves is not particularly limited, and various extraction methods commonly used in the food processing field can be used, including, for example, solvent extraction, air flow extraction, and squeeze extraction. If necessary, further processing such as solid-liquid separation such as precipitation or filtration, concentration, centrifugation, drying (e.g., spray drying, freeze drying), or powderization may be carried out.

[0030] Here, the extraction solvent used in solvent extraction is preferably water (e.g., hard water, soft water, ion-exchanged water, and natural water). The amount of extraction solvent can be appropriately selected by those skilled in the art and is not particularly limited. For example, when the extraction solvent is water, the amount is 1 to 100 times the amount (mass) of tea leaves.

[0031] The extraction temperature and extraction time are not particularly limited and can be appropriately selected by those skilled in the art. For example, when the extraction solvent is water, the temperature and extraction time can be 10 to 120°C and 1 minute to 12 hours.

[0032] An example of an extraction process is a method in which tea leaves are soaked and stirred in water at 0 to 90°C for 1 minute to 24 hours, and then filtered or centrifuged. The extraction conditions, such as temperature and time, are not particularly limited and can be selected and set by a person skilled in the art depending on the type and amount of tea leaves.

[0033] In preparing the tea extract, a concentrate or purified product of tea extract such as tea extract or tea powder may be used, and examples of commercially available products that can be used include Polyphenon (manufactured by Mitsui Norin Co., Ltd.), Sunphenon (manufactured by Taiyo Kagaku Co., Ltd.), and Theafuran (manufactured by Ito En Co., Ltd.) Furthermore, these tea concentrates (preferably green tea concentrates, black tea concentrates, and / or oolong tea concentrates, etc.) and purified tea products (preferably purified green tea, black tea, and / or purified oolong tea, etc.) may be used alone, as is, or after being dissolved or diluted with water, or multiple types may be used in combination, or may be used in combination with a tea extract.

[0034] The beverage of the present invention may contain beverage additives commonly used in the production of beverages, such as acidulants, flavorings, colorings, fruit juices, sweeteners (including high-intensity sweeteners), dairy ingredients, ground tea leaves (such as matcha and powdered tea), and food additives (such as antioxidants, preservatives, thickening agents, emulsifiers, dietary fiber, pH adjusters, and bittering agents). The beverage of the present invention may or may not contain microbial cells. In embodiments where the beverage of the present invention contains microbial cells, the concentration of the microbial cells is not particularly limited, but may be, for example, 0.01 wt % or more, preferably 0.05 wt % or more, more preferably 0.25 wt % or more, even more preferably 0.5 wt % or more, and even more preferably 0.75 wt % or more, expressed as the ratio of the dry weight of the microbial cells to the weight of the beverage. The upper limit of the aforementioned ratio is not particularly limited, but is preferably 1 wt % or less or 0.8 wt % or less, from the viewpoint of maintaining the inherent flavor and aroma balance of the tea beverage. More specifically, the concentration is, for example, 0.01 to 1% by weight, preferably 0.05 to 1% by weight, and more preferably 0.25 to 1% by weight. The concentration of microbial cells in the beverage of the present invention (i.e., the ratio (%) of the dry weight of microbial cells to the weight of the beverage) can be measured by known methods such as turbidity measurement. Furthermore, the beverage of the present invention may further contain a fermentation product by lactic acid bacteria, but preferably does not contain one.

[0035] The beverage of the present invention is a packaged tea beverage. Such a container refers to a sealed container that can prevent contact between the contents and the outside air, and examples thereof include metal cans, barrels, plastic bottles (e.g., PET bottles and cups), paper containers, bottles, and pouches.

[0036] (Production of the beverage of the present invention) The first beverage of the present invention contains a tea extract produced by the production method of the present invention. The tea extract contained in the second beverage of the present invention may be a tea extract produced by the production method of the present invention, a tea extract produced by another production method, or a mixture of both tea extracts, but is preferably a tea extract produced by the production method of the present invention. Examples of such other production methods include using a tea extract in which the ratio of gallated catechins to free catechins is relatively low.

[0037] (Production method of the present invention) The production method of the present invention is not particularly limited as long as it is a method for producing a tea extract, characterized by including step A of contacting a raw material tea extract with microbial cells.

[0038] (Microbial cells) Microbial cells refer to microbial cells or parts thereof (i.e., processed products of microbial cells). Parts of microbial cells are not particularly limited as long as they achieve the effects of the present invention, but preferred examples include processed products of microbial cells, such as microbial cell walls (e.g., yeast cell walls). The microbial cells used may be killed, live, or a combination of killed and live cells, but killed cells are preferred. Microbial cells may be dried (i.e., dried cells) or non-dried (e.g., wet cells), but from the viewpoint of storage stability, dried cells are preferred, and a suitable example is a dry powder. After contacting live microbial cells with the raw green tea extract, the microorganisms in the beverage may be killed by sterilization during beverage preparation to form killed cells; however, it is preferred to contact pre-killed cells with the raw tea extract.

[0039] The method for preparing microbial cells is not particularly limited, and examples thereof include a method in which the cells are collected by filtering or centrifuging the medium in which the microorganisms have been cultured. When killed cells are to be obtained, conventional means for killing microorganisms, such as heating, ultraviolet irradiation, or gamma-ray irradiation, can be used.

[0040] The concentration of microbial cells used in producing the beverage of the present invention is not particularly limited as long as the effects of the present invention are obtained, but the ratio (%) of the dry weight of microbial cells to the weight of the raw tea extract or beverage is, for example, 0.01 wt% or more, preferably 0.05 wt% or more, more preferably 0.25 wt% or more, even more preferably 0.5 wt% or more, and more preferably 0.75 wt% or more. The upper limit of the above ratio is not particularly limited and can be, for example, 3 wt% or less. However, if the microbial cells are to be left in the beverage of the present invention, preferred concentrations are, for example, 1 wt% or less or 0.8 wt% or less, from the viewpoint of maintaining the inherent flavor and aroma balance of the tea beverage. More specifically, the concentration can be, for example, 0.01 to 1 wt%, preferably 0.05 to 1 wt%, and more preferably 0.25 to 1 wt%.

[0041] (Type of microorganism) The type of microorganism in the present invention is not particularly limited as long as the effects of the present invention can be obtained, and examples thereof include one or more types selected from the group consisting of bacteria and yeasts.

[0042] The "bacteria" is not particularly limited, but may include one or more species selected from the group consisting of lactic acid bacteria, Bifidobacterium bacteria, and Clostridium bacteria, and preferably includes one or more species selected from the group consisting of lactic acid bacteria and Bifidobacterium bacteria.

[0043] (lactic acid bacteria) "Lactic acid bacteria" is a general term for all those taxonomically recognized as lactic acid bacteria, and is not limited by genus, species, strain, etc. Such "lactic acid bacteria" include bacteria that lactic-ferment sugars to produce large amounts of lactic acid (preferably 50% or more of the lactic acid consumed), such as bacteria of the genus Lactococcus, Lactobacillus, Streptococcus, Leuconostoc, Pediococcus, and Enterococcus.

[0044] The genus or species of lactic acid bacteria is not particularly limited, but examples include one or more bacteria selected from the group consisting of Lactococcus, Lactobacillus, Streptococcus, Leuconostoc, Pediococcus, and Enterococcus, preferably one or more bacteria selected from the group consisting of Lactococcus and Lactobacillus, more preferably one or more bacteria selected from the group consisting of Lactococcus lactis and Lactobacillus paracasei, and even more preferably one or more bacteria selected from the group consisting of Lactococcus lactis subsp. lactis.

[0045] More specific preferred embodiments of the lactic acid bacteria of the present invention include Lactococcus lactis subsp. lactis (Lactococcus lactis subsp. lactis JCM 5805, Lactococcus lactis subsp. lactis NBRC12007, Lactococcus lactis subsp. lactis NRIC 1150, Lactococcus lactis subsp. lactis JCM20101, Lactococcus lactis subsp. lactis JCM7638, Lactococcus lactis subsp. lactis ATCC 11454, etc.), Lactococcus lactis subsp. lactis biovar diacetylactis (Lactococcus lactis subsp. lactis biovar diacetylactis), and Lactococcus lactis subsp. lactis biovar diacetylactis. diacetylactis, Lactococcus lactis subsp. cremoris (Lactococcus lactis subsp. cremoris JCM 16167, Lactococcus lactis subsp. cremoris NBRC100676, etc.), Lactococcus raffinolactis, Lactococcus piscium, Lactococcus plantarum, Lactococcus garvieae (Lactococcus garvieae NBRC100934, etc.), Lactococcus lactis subsp. hordniae) (Lactococcus lactis subsp. hordniae JCM1180, Lactococcus lactis subsp. hordniae JCM11040, etc.), Lactobacillus acidophilus (Lactobacillus acidophilus L-92, etc.),Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. delbrueckii, Lactobacillus delbrueckii subsp. lactis, Lactobacillus casei, Lactobacillus paracasei (Lactobacillus paracasei KW3110 strain and Lactobacillus paracasei MCC1849 strain, etc.), Lactobacillus gasseri (Lactobacillus gasseri SBT2055 strain), Lactobacillus helveticus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum (Lactobacillus plantarum L-137 strain, etc.), Lactobacillus brevis, Lactobacillus casei subsp. rhamnosus (Lactobacillus rhamnosus GG strain), Lactobacillus pentosus, Lactobacillus fermentum, Lactobacillus fructivorans, Lactobacillus hilgardii hilgardii), Streptococcus salivarius subsp. thermophilus, Leuconostoc mesenteroides subsp. cremoris,Leuconostoc lactis, Pediococcus damnosus, Pediococcus pentosaceus, Pediococcus acidilactici (Pediococcus acidilactici JCM8797 strain and Pediococcus acidilactici K15, etc.), Enterococcus faecalis, Pediococcus cellicola, Pediococcus laussenii, Pediococcus ethanolidurans ethanolidurans, Pediococcus inopinatus, Pediococcus parvulus, Pediococcus stilesii, and Enterococcus faecium, and preferably Lactococcus lactis subsp. lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subsp. cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garvieae, Lactococcus lactis subsp. holdoniae, Lactobacillus acidophilus, Lactobacillus acidophilus, Lactococcus lactis subsp. lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subsp. cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garvieae, Lactococcus lactis subsp. holdoniae, Lactobacillus acidophilus, Lactobacillus acidophilus, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subsp. Lactobacillus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. delbrueckii, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subsp. rhamnosus, Lactobacillus pentosus,The bacterial strains include one or more bacteria selected from the group consisting of Lactobacillus fermentum, Streptococcus salivarius subsp. thermophilus, Leuconostoc mesentroides subsp. cremoris, and Leuconostoc lactis, and more preferably Lactococcus lactis subsp. lactis, Lactococcus lactis biovariant diacetylactis, Lactococcus lactis subsp. cremoris, Lactococcus raffinolactis, Lactococcus pythium, Lactococcus plantarum, Lactococcus garvieae, Lactococcus lactis subsp. holdoniae, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. delbrueckii, Lactobacillus casei , Lactobacillus paracasei, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus casei subsp. rhamnosus, Lactobacillus pentosus, and Lactobacillus fermentum, and more preferably Lactococcus lactis subsp. lactis and Lactobacillus lactis JCM 7638, Lactococcus lactis subsp. lactis ATCC 11454, Lactobacillus paracasei KW3110, and Lactobacillus paracasei MCC1849; and more preferably, one or two or more bacteria selected from the group consisting of Lactococcus lactis subsp. lactis JCM 5805, Lactococcus lactis subsp. lactis JCM 20101, Lactococcus lactis subsp. lactis NBRC12007, Lactococcus lactis subsp. lactis NRIC1150, Lactococcus lactis subsp. lactis JCM 7638, Lactococcus lactis subsp. lactis ATCC11454, Lactobacillus paracasei KW3110, and Lactobacillus paracasei MCC1849.Particularly preferred are one or more bacteria selected from the group consisting of Lactococcus lactis subsp. lactis JCM5805, Lactobacillus paracasei KW3110, and Lactobacillus paracasei MCC1849, and more preferably Lactococcus lactis subsp. lactis JCM5805.

[0046] Another preferred embodiment of the lactic acid bacteria of the present invention includes one or more species selected from the group consisting of bacteria of the genus Lactococcus, and preferably Lactococcus lactis subsp. lactis JCM 5805, Lactococcus lactis subsp. lactis NBRC12007, Lactococcus lactis subsp. lactis NRIC 1150, Lactococcus lactis subsp. lactis JCM20101, Lactococcus lactis subsp. lactis JCM7638, Lactococcus lactis subsp. lactis ATCC 11454, and Lactococcus garvieae NBRC 100934, Lactococcus lactis subsp. cremoris JCM16167, Lactococcus lactis subsp. cremoris NBRC100676, Lactococcus lactis subsp. holdoniae JCM 1180, and Lactococcus lactis subsp. holdoniae JCM11040.

[0047] The present invention also includes strains equivalent to the lactic acid bacteria strains mentioned herein, as long as they achieve the effects of the present invention. Here, "equivalent strains" refers to strains derived from the above strains, strains from which the above strains are derived, or descendant strains of those strains. Equivalent strains may also be preserved in other culture collections. Figure 1 shows strains derived from Lactococcus lactis subsp. lactis JCM5805 and the strain from which Lactococcus lactis subsp. lactis JCM5805 is derived. Strains equivalent to Lactococcus lactis subsp. lactis JCM5805 shown in Figure 1 can also be used as lactic acid bacteria of the present invention, as long as they achieve the effects of the present invention. As used herein, the term "Lactococcus lactis subsp. lactis JCM5805" includes equivalent strains. Among the above lactic acid bacteria strains, the JCM strain can be obtained from the Microbial Materials Development Laboratory, RIKEN BioResource Center (1-1 Takanodai 3-chome, Tsukuba, Ibaraki Prefecture, Japan), the NBRC strain can be obtained from the Biological Genetic Resources Division, National Institute of Technology and Evaluation (5-8 Kazusa Kamatari 2-chome, Kisarazu, Chiba Prefecture, Japan), the NRIC strain can be obtained from the Culture Collection, Tokyo University of Agriculture (1-1 Sakuragaoka 1-chome, Setagaya-ku, Tokyo, Japan), and the ATCC strain can be obtained from the American Type Culture Collection (USA). As mentioned above, the Lactococcus lactis subsp. lactis JCM5805 strain can be obtained from the Microbial Engineering Division of the RIKEN BioResource Center, as described above. However, in the present invention, identical strains of the JCM5805 strain stored in collections other than the Microbial Engineering Division of the RIKEN BioResource Center can also be used. Specifically, identical strains of the JCM5805 strain can be obtained from the Biological Genetic Resources Division of the National Institute of Technology and Evaluation (2-5-8 Kazusa Kamatari, Kisarazu, Chiba Prefecture), the Strain Collection of Tokyo University of Agriculture (1-1-1 Sakuragaoka, Setagaya-ku, Tokyo), the American Type Culture Collection (USA), and other sources.

[0048] (Bifidobacterium) The species of the genus Bifidobacterium is not particularly limited, but may include Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium animalis subsp. animalis, Bifidobacterium animalis subsp. lactis, Bifidobacterium adolescentis, Bifidobacterium Examples of the bacterium include one or more bacteria selected from the group consisting of Bifidobacterium adolescentis, Bifidobacterium angulatum, Bifidobacterium catenulatum, and Bifidobacterium pseudocatenulatum, and preferably one or more bacteria selected from the group consisting of Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum subsp. longum, Bifidobacterium longum subsp. infantis, Bifidobacterium animalis subsp. animalis, and Bifidobacterium animalis subsp. lactis.

[0049] (Clostridium bacteria) Examples of Clostridium species include those that can be used in foods and beverages, specifically Clostridium butyricum, known as butyric acid bacteria.

[0050] (yeast) Examples of yeast include species that can be used in foods and beverages, such as the genera Saccharomyces, Torulopsis, Mycotorula, Torulaspora, Candida, Rhodotorula, Pichia, and Saccharomycopsis, with the genus Saccharomyces being preferred. Specific examples of yeast species that can be used in the present invention include Saccharomyces cerevisiae, Saccharomyces carlsbergensis, Saccharomyces uvarum, Saccharomyces rouxii, Saccharomyces lipolytica, Torulopsis utilis, Torulopsis candida, Mycotorula japonica, Mycotorula lipolytica, Torulaspora delbrueckii, Torulaspora fermentatii, and the like. Examples of suitable fungi include one or more fungi selected from the group consisting of Candida fermentati, Candida sake, Candida tropicalis, Candida utilis, Pichia anomala, Pichia suaveolens, Pichia farinosa, Rhodotorula rubra, and Saccharomycopsis fibligera, and preferably Saccharomyces cerevisiae.

[0051] (Process A) Step A in the present invention is not particularly limited as long as it is step A in which a raw material tea extract is brought into contact with microbial cells.

[0052] The raw material tea extract refers to the tea extract used as a raw material for producing the beverage of the present invention. The raw material tea extract to be contacted with the microbial cells is preferably a liquid. The temperature of the raw material tea extract to be contacted with the microbial cells is not particularly limited, but examples include 1 to 140°C, 5 to 140°C, and 5 to 80°C. The time for which the raw material tea extract is contacted with the microbial cells in step A is also not particularly limited, and examples include 30 seconds to 2 hours, and from the viewpoint of tea extract production efficiency, preferably 30 seconds to 30 minutes, or 30 seconds to 10 minutes.

[0053] (Process B) The production method of the present invention may or may not include a step B of removing the microbial cells from step A after step A, but preferably does include the step B. The method for removing the microbial cells is not particularly limited, but a preferred example is a method in which the raw material tea extract containing the microbial cells is centrifuged to remove the microbial cells from the raw material extract.

[0054] (Optional process other than process B) The production method of the present invention has step A as an essential step. The production method of the present invention may further include an optional step in addition to step A, or in addition to steps A and B. Such optional steps include a step of preparing a raw material tea extract, a heat sterilization step, and a step of filling into a container. The step of contacting the raw material tea extract with the microbial cells may be carried out at any stage within the production process of the present invention, as long as the raw material tea extract and the microbial cells come into contact with each other. For example, the microbial cells may be contacted with the raw material tea extract simultaneously with the preparation of the raw material tea extract, such as a method of contacting a solid raw material tea extract with the microbial cells and then adding water thereto, or a method of extracting the raw material tea extract from tea leaves with water containing the microbial cells. Alternatively, the microbial cells may be added to a container in the final stage of production of a packaged tea beverage to contact the raw material tea extract with the microbial cells.

[0055] When heat sterilization is carried out in the production of the tea beverage of the present invention, various heat sterilization methods commonly used in the food industry can be used, such as a hot water spray type, hot water storage type, or steam type retort sterilizer, or a tube type or plate type continuous liquid sterilizer.

[0056] (Packaged tea beverage with reduced gallate-type catechins and reduced astringency and browning) The beverage of the present invention is a packaged tea beverage with reduced gallate-type catechins and reduced astringency and browning.

[0057] In this specification, a packaged tea beverage with reduced gallated catechins means (a) a packaged tea beverage in which the ratio of gallated catechins to catechins is less than 33%, or (b) a packaged tea beverage in which the ratio of gallated catechins to catechins is reduced compared to a packaged tea beverage produced using the same raw materials and the same production method, except that microbial cells were not brought into contact with the raw tea extract (hereinafter also referred to as the "control beverage of the present invention").

[0058] In this specification, a packaged tea beverage with reduced astringency and browning means (a) a packaged tea beverage in which the ratio of gallate-type catechin concentration to catechin concentration is less than 33%, or (b) a packaged tea beverage in which astringency and browning are reduced compared to the control beverage of the present invention.

[0059] A trained panel can easily and clearly determine the degree of astringency and browning in a particular packaged tea beverage, and how such astringency and browning are compared (e.g., whether they are reduced) with the control beverage of the present invention.

[0060] (Reduction method of the present invention) The reduction method of the present invention is not particularly limited as long as it is a method for reducing astringency and browning of a tea extract, characterized by including step A of contacting a raw material tea extract with microbial cells. The reduction method of the present invention may or may not include step B, which removes the microbial cells of step A, after step A, but preferably does include it. Furthermore, the reduction method of the present invention may further include an optional step in addition to step A, or in addition to steps A and B. Step A, step B, the optional step, etc. are the same as those described above (the production method of the present invention).

[0061] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. [Example]

[0062] [Test 1] Confirmation of changes in the components of tea extract by contacting microbial cells with tea extract 1 The following test was carried out to examine how the components of a tea extract change when the tea extract is brought into contact with microbial cells.

[0063] Green tea leaves were extracted in hot water and subjected to solid-liquid separation to prepare a green tea extract (tannin concentration 400 mg / L). This green tea extract was mixed with 0.05% by weight of dried killed bacterial powder of Lactococcus lactis subsp. lactis JCM5805, and left to stand at 20°C for 2 hours. The killed bacterial cells were then removed by centrifugation. L-ascorbic acid and sodium bicarbonate (0.04% by weight each) were added and mixed, and the mixture was heated at 140°C to prepare the sample beverage of Test Example 1.

[0064] The sample beverage of Test Example 2 was prepared in the same manner as in Test Example 1, except that the temperature and time for standing was set at 80°C for 30 seconds.

[0065] The sample beverage of Test Example 3 was prepared in the same manner as in Test Example 1, except that the temperature and time for standing was set at 140°C for 30 seconds.

[0066] A green tea extract to which no dried killed cell powder of the JCM5805 strain was added was used as a control (comparison) beverage.

[0067] For each of the beverages of the Comparative Example and Test Examples 1 to 3, the Brix value, pH, tannin concentration, caffeine concentration, and concentrations of various amino acids were measured, and the results are shown in Table 1. Amino acids not listed in Table 1 were not detected. Furthermore, for each of the beverages of the Comparative Example and Test Examples 1 to 3, the results of measuring the concentrations of various catechins are shown in Table 2.

[0068] [Table 1]

[0069] As can be seen from the results in Table 1, when lactic acid bacteria cells were brought into contact with the raw tea extract, the concentrations of amino acids and caffeine were not affected, but the tannin concentration was reduced by approximately 10%.

[0070] [Table 2]

[0071] As can be seen from the results in Table 2, when raw tea extract was contacted with lactic acid bacteria cells, the concentration of free catechins was hardly affected, but the concentration of gallated catechins was reduced by approximately 20% or more. Furthermore, when raw tea extract was contacted with lactic acid bacteria cells to reduce the concentration of gallated catechins, the ratio of the concentration of gallated catechins to the concentration of catechins was less than 33%. Furthermore, when raw tea extract was contacted with lactic acid bacteria cells to reduce the concentration of gallated catechins, the ratio of the concentration of gallated catechins to the concentration of caffeine was less than 100%.

[0072] [Test 2] Confirmation of changes in the components of tea extracts by contacting microbial cells with tea extracts 2 The following test was carried out to examine whether the concentration of gallate-type catechins would decrease even when cells of microorganisms other than lactic acid bacteria were brought into contact.

[0073] Green tea leaves were extracted in hot water and subjected to solid-liquid separation to prepare a green tea extract (tannin concentration 400 mg / L). This green tea extract was mixed with 0.05% by weight of dried killed bacterial powder of Lactococcus lactis subsp. lactis JCM5805, left to stand at 90°C for 30 seconds, then centrifuged to remove the killed bacterial cells. L-ascorbic acid and sodium bicarbonate (0.04% by weight each) were added and mixed, and the mixture was heated at 140°C to prepare the sample beverage of Test Example 4.

[0074] In addition, the sample beverage of Test Example 5 was prepared using the same method as Test Example 4, except that dried killed cell powder of commercially available baker's yeast A (Saccharomyces yeast) was used instead of dried killed cell powder of lactic acid bacteria strain JCM5805.

[0075] In addition, the sample beverage of Test Example 6 was prepared using the same method as Test Example 4, except that dried killed cell powder of commercially available baker's yeast B (Saccharomyces yeast) was used instead of dried killed cell powder of lactic acid bacteria strain JCM5805.

[0076] A green tea extract to which neither lactic acid bacteria nor yeast cells were added was used as a control (comparison) beverage.

[0077] The Brix value, pH, tannin concentration, and caffeine concentration of each of the beverages in the Comparative Example and Test Examples 4 to 6 were measured, and the results are shown in Table 3. Furthermore, the concentrations of various catechins were measured for each of the beverages in the Comparative Example and Test Examples 4 to 6, and the results are shown in Table 4.

[0078] [Table 3]

[0079] As can be seen from the results in Table 3, even when the raw tea extract was contacted with yeast cells instead of lactic acid bacteria cells, the caffeine concentration was not affected, but the tannin concentration was reduced by approximately 10 to 20%.

[0080] [Table 4]

[0081] As can be seen from the results in Table 4, even when yeast cells, rather than lactic acid bacteria cells, were contacted with the raw tea extract, the concentration of free catechins was hardly affected, while the concentration of gallated catechins was reduced by approximately 20% or more. Furthermore, it was shown that the reduction of gallated catechins by contacting the raw tea extract with microbial cells resulted in a ratio of gallated catechins to catechins of less than 33%. Furthermore, it was shown that the reduction of gallated catechins by contacting the raw tea extract with microbial cells resulted in a ratio of gallated catechins to caffeine of less than 100%.

[0082] [Test 3] Confirmation of changes in the components of tea extract due to differences in the concentration of microbial cells in contact with tea extract The following test was carried out to investigate how the components of the tea extract change depending on the concentration of microbial cells brought into contact with the tea extract.

[0083] Green tea leaves were extracted in hot water and subjected to solid-liquid separation to prepare a green tea extract (tannin concentration 800 mg / L). 0.25 wt% of dried killed cell powder of commercially available baker's yeast B (Saccharomyces yeast) was added to and mixed with this green tea extract, allowed to stand at 90°C for 30 seconds, centrifuged to remove the killed cells, and then diluted 2-fold with water to prepare the sample beverage of Test Example 7.

[0084] In addition, the sample beverage of Test Example 8 was prepared in the same manner as in Test Example 7, except that the concentration of the dried killed cell powder of baker's yeast B added was 0.5 wt % instead of 0.25 wt %.

[0085] In addition, the sample beverage of Test Example 9 was prepared in the same manner as in Test Example 7, except that the concentration of the dried killed cell powder of baker's yeast B added was 0.75 wt % instead of 0.25 wt %.

[0086] A green tea extract diluted twice with water without adding yeast cells was used as a control (comparison) beverage.

[0087] The concentrations of various catechins in the beverages of the Comparative Example and Test Examples 7 to 9 were measured, and the results are shown in Table 5.

[0088] [Table 5]

[0089] As can be seen from the results in Table 5, when the raw tea extract was contacted with microbial cells, the higher the concentration of the microbial cells, the greater the reduction in the concentration of gallated catechins. It was also shown that the higher the concentration of the microbial cells contacted with the raw tea extract, the lower the ratio of the concentration of gallated catechins to the concentration of catechins.

[0090] [Test 4] Confirmation of changes in the components of tea extract due to differences in temperature when microbial cells are brought into contact with tea extract The following test was carried out to investigate how the components of the tea extract change depending on the temperature at which the microbial cells are brought into contact with the tea extract.

[0091] Green tea leaves were extracted in hot water and subjected to solid-liquid separation to prepare a green tea extract (tannin concentration 800 mg / L). 0.25% by weight of dried killed cell powder of commercially available baker's yeast B (Saccharomyces yeast) was added to and mixed with this green tea extract, allowed to stand at 5°C for 10 minutes, centrifuged to remove the killed cells, and then diluted 2-fold with water to prepare the sample beverage of Test Example 10.

[0092] Furthermore, the sample beverage of Test Example 11 was prepared in the same manner as in Test Example 10, except that the temperature during standing was set to 20°C instead of 5°C.

[0093] Furthermore, the sample beverage of Test Example 12 was prepared in the same manner as in Test Example 10, except that the temperature during standing was set to 50°C instead of 5°C.

[0094] Furthermore, the sample beverage of Test Example 13 was prepared in the same manner as in Test Example 10, except that the temperature during standing was set to 80°C instead of 5°C.

[0095] A green tea extract diluted twice with water without adding yeast cells was used as a control (comparison) beverage.

[0096] The concentrations of various catechins were measured for each of the beverages of the Comparative Example and Test Examples 10 to 13, and the results are shown in Table 6.

[0097] [Table 6]

[0098] As can be seen from the results in Table 6, it was shown that only gallated catechins were reduced to the same extent regardless of the temperature at which the microbial cells were contacted with the raw tea extract. Furthermore, when the results in Table 6 and Table 1 were taken into consideration together, it was shown that the degree of reduction of gallated catechins was roughly the same within the temperature range of 5 to 140°C. It was also shown that when the microbial cells were contacted with the raw tea extract, the ratio of the concentration of gallated catechins to the concentration of catechins was less than 33% regardless of the temperature.

[0099] [Test 5] Confirmation of changes in flavor and appearance of tea extract over time by contacting microbial cells with tea extract The following tests were conducted to confirm the changes in flavor and appearance of tea extract over time caused by contacting the tea extract with microbial cells. For comparison with conventional methods, sample beverages using polyvinylpolypyrrolidone (PVPP) and tannase were prepared using conventional methods. Tannase hydrolyzes the carboxyl ester bond in gallated catechins, producing free catechins and gallic acid.

[0100] Green tea leaves were extracted in hot water and subjected to solid-liquid separation to prepare a green tea extract (1380 mg / L). 0.08% by weight of dried killed brewer's yeast (Saccharomyces yeast) powder was added to this green tea extract and mixed. After standing at room temperature for 30 minutes, the mixture was centrifuged to remove the killed cells. The mixture was then diluted three times with water, and a predetermined amount of vitamin C and sodium bicarbonate was added. The mixture was sterilized at 140°C and filled into a PET bottle to prepare the sample beverage of Test Example 14.

[0101] In addition, the sample beverage of Test Example 15 was prepared using the same method as Test Example 14, except that the concentration of dried killed cell powder of brewer's yeast (Saccharomyces yeast) added was 0.16 wt % instead of 0.08 wt %.

[0102] In addition, 0.04% by weight of polyvinylpolypyrrolidone (PVPP) powder was added to the above-mentioned green tea extract and mixed, and after leaving to stand at room temperature for 30 minutes, the PVPP was removed by centrifugation. The mixture was then diluted three times with water, and a specified amount of vitamin C and baking soda was added. The mixture was sterilized at 140°C and filled into a PET bottle to prepare the sample beverage of Test Example 16.

[0103] Furthermore, the sample beverage of Test Example 17 was prepared in the same manner as in Test Example 16, except that the concentration of the PVPP powder added was 0.08 wt % instead of 0.04 wt %.

[0104] In addition, 0.01% by weight of tannase enzyme powder ("Tannase": Mitsubishi Chemical Corporation) was added to the above-mentioned green tea extract and mixed, and after leaving to stand for 30 minutes at 40°C, it was inactivated, diluted three times with water, and a specified amount of vitamin C and baking soda was added, sterilized at 140°C, and filled into a PET bottle to prepare the sample beverage of Test Example 18.

[0105] In addition, the sample beverage of Test Example 19 was prepared in the same manner as in Test Example 18, except that the concentration of tannase enzyme powder added was 0.04 wt % instead of 0.01 wt %.

[0106] A control (comparison) beverage was prepared by diluting green tea extract three times with water without adding yeast cells, adding a specified amount of vitamin C and baking soda, sterilizing it at 140°C, and filling it into a PET bottle.

[0107] For each of the beverages in the comparative example and test examples 14 to 19, the Brix value, pH, tannin concentration, total concentration of eight catechins, total concentration of four free catechins, total concentration of four gallate-type catechins, gallic acid concentration, and caffeine concentration were measured and the results are shown in Table 8.

[0108] Eight trained expert panelists conducted sensory evaluation tests on the appearance, sweetness, roughness, and drinking quality of each of the beverages in the Comparative Example and Test Examples 14 to 19 using the five-point rating scale shown in Table 7 below. For appearance, sweetness, roughness, and drinking quality, the difference between 1 and 2 points, the difference between 2 and 3 points, the difference between 3 and 4 points, and the difference between 4 and 5 points were all considered to be the same. The evaluation of the appearance, sweetness, roughness, and drinking quality of each test example sample was performed by rounding the average of the panel's ratings to the nearest tenth. A rating of 1 to 2.5 points but less than 2.5 points was assigned a "x," a rating of 2.5 to 3.5 points was assigned a "△," and a rating of 3.5 points or more was assigned a "good." In addition, for the overall evaluation of flavor, if the average score of the three evaluation points of sweetness, roughness, and drinkability was 1 point or more but less than 2.5 points, it was marked as ×, if it was 2.5 points or more but less than 3.5 points, it was marked as △, and if it was 3.5 points or more, it was marked as ◯.

[0109] [Table 7]

[0110] Table 8 shows the results of the sensory evaluation test for each of the beverages of the Comparative Example and Test Examples 14 to 19.

[0111] [Table 8]

[0112] As can be seen from the results in Table 8, the ratio of gallate catechin concentration to catechin concentration was reduced even when PVPP or tannase was used. However, when tannase was used, the liquid color became slightly reddish-yellow and browned, and the flavor was also poorly evaluated. When PVPP was used, although the appearance was fine, the sweetness, roughness, and drinkability were all reduced, resulting in a flat, bland taste, which was not well evaluated. On the other hand, when the raw tea extract was contacted with microbial cells, the appearance and flavor were better than when PVPP or tannase was used. Specifically, the flavor was reduced in bitterness and astringency, resulting in a sweeter, smoother taste. These results demonstrate that the method of the present invention using microbial cells has significantly superior effects compared to conventional methods using PVPP or tannase. [Industrial Applicability]

[0113] According to the present invention, it is possible to provide (i) a packaged tea beverage having reduced gallated catechins, (ii) a method for producing a tea extract having reduced gallated catechins, and (iii) a method for reducing the astringency and browning of a tea extract.

Claims

1. A packaged tea beverage comprising: The concentration of catechins in the packaged tea beverage is 400 mg / L or less; The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and The packaged tea beverage contains a tea extract produced by a tea extract production method including a step A of contacting a raw material tea extract with microbial cells.

2. A packaged tea beverage comprising: The concentration of catechins in the packaged tea beverage is 400 mg / L or less; The ratio of the concentration of gallate-type catechins to the concentration of catechins in the packaged tea beverage is less than 33%, and The packaged tea beverage, wherein the ratio of the catechins concentration to the tannin concentration in the packaged tea beverage is 70% or more.

3. 3. The packaged tea beverage according to claim 1 or 2, having a tannin concentration of 500 mg / L or less.

4. 3. The packaged tea beverage according to claim 1 or 2, wherein the ratio of the concentration of gallate-type catechins to the concentration of caffeine is 30% or more and less than 100%.

5. 3. The packaged tea beverage according to claim 1 or 2, having a caffeine concentration of 150 mg / L or less.

6. A method for producing a tea extract, comprising step A of contacting a raw material tea extract with microbial cells.

7. The method according to claim 6, wherein the microbial cells are cells of one or more types selected from the group consisting of yeast and lactic acid bacteria.

8. The method according to claim 6, further comprising, after step A, step B of removing the microbial cells of step A.

9. A method for reducing astringency and browning in a tea extract, comprising step A of contacting a raw tea extract with microbial cells.

10. The method according to claim 9, wherein the microbial cells are cells of one or more types selected from the group consisting of yeast and lactic acid bacteria.

11. The method according to claim 9 , further comprising, after step A, step B of removing the microbial cells obtained in step A.

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