Bottled unsweetened tea beverage

Abstract

To provide a bottled, unsweetened tea beverage that retains its astringent taste even after storage. [Solution] In a bottled unsweetened tea beverage, a fermented tea extract and an unfermented tea extract are blended, the concentration of theaflavins is set to 0.05 to 0.20 mg / 100 ml, the concentration of non-polymerized catechins is set to 5.0 to 50.0 mg / 100 ml, and the ratio of the concentration of non-polymerized catechins to the concentration of tannins is set to 0.40 or less.

Description

[Technical Field]

[0001] The present invention relates to a packaged sugar-free tea beverage. In particular, it relates to a packaged sugar-free tea beverage that contains a fermented tea extract and a non-fermented tea extract, and is adjusted such that the concentration of theaflavin, the concentration of non-polymerized catechins, and the ratio of the concentration of non-polymerized catechins to the concentration of tannins fall within specific ranges. [Background Art]

[0002] RTD (Ready-To-Drink) beverages (packaged beverages in bottles or cans that can be drunk immediately after opening the cap) have formed a large market because they provide the advantages of convenience and portability to busy modern people. In particular, packaged sugar-free tea beverages, which are a standard thirst-quenching drink, are highly popular. Among these, sugar-free tea beverages made from leaves of *Camellia sinensis*, such as green tea beverages, oolong tea beverages, and black tea beverages, contain appropriate amounts of caffeine in addition to the flavor and aroma of tea leaves. Therefore, they can be expected to have awakening and refreshing effects, and combined with the growing health consciousness, they meet consumer preferences and are particularly popular.

[0003] However, for packaged tea beverages, there is a problem in that the flavor changes due to long-term distribution and storage, making it difficult to perceive the fresh flavor characteristic of tea beverages when drinking. In response to this, various methods for preventing quality changes in packaged tea beverages have been proposed. For example: a method for suppressing aging deterioration of packaged beverages by adjusting the dissolved oxygen content in the liquid during the primary heating and deoxidation step to be in the range of 0.1 to 3.0 ppm in a method for producing packaged beverages including a primary heating-deoxidation step and a secondary heating-sterilization step (Patent Document 1); a method for suppressing photodegradation in high-clarity green tea beverages by blending one or more selected from the group consisting of grape seed extract, bayberry extract, and vitamin E (Patent Document 2); and a method for removing retort odor from green tea beverages by impregnating cyclodextrin into a green tea extract, then filling the mixture into a can and subjecting it to heat treatment to obtain a green tea beverage (Patent Document 3). [Patent Document 1] Japanese Patent Publication No. 2015-208303 [Patent Document 2] Japanese Patent Publication No. 2019-170200 [Patent Document 3] Japanese Patent Application Publication No. 1-174328 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] As mentioned above, tea beverages that can be stored for long periods, such as bottled tea beverages, have the problem of changing flavor and losing their fresh aroma. This problem is observed in both unfermented green tea and fermented teas such as oolong tea and black tea. As mentioned above, various methods have been proposed to prevent changes in the quality of bottled tea beverages, but providing new means to prevent changes would broaden the possibilities for manufacturing processes and material selection for bottled unsweetened tea beverages, and is generally desirable. In particular, the inventors focused on the increase in astringency as a change in flavor of tea beverages over time. The present invention aims to provide a new bottled unsweetened tea beverage that exhibits less astringency even after storage. [Means for solving the problem]

[0005] As a result of diligent research by the present inventors to achieve the above objectives, we have found that by mixing a fermented tea extract with an unfermented tea extract and adjusting the concentration of theaflavins, the concentration of non-polymerized catechins, and the ratio of the concentration of non-polymerized catechins to the concentration of tannins, it is possible to obtain a bottled unsweetened tea beverage with less astringency even after storage. The present invention is not limited to these, but includes the following. (Aspect 1) A packaged unsweetened tea beverage, Contains fermented tea extract and unfermented tea extract. The theaflavin concentration is 0.05-0.20 mg / 100 ml. The concentration of non-polymerized catechins is 5.0 to 50.0 mg / 100 ml. The beverage in which the ratio of the concentration of non-polymerized catechins to the concentration of tannins is 0.40 or less. (Aspect 2) The unsweetened, bottled tea beverage according to Aspect 1, wherein the fermented tea extract contains black tea extract. (Aspect 3) A packaged unsweetened tea beverage according to Aspect 1 or 2, wherein the Brix is ​​0.50 or less. (Aspect 4) A bottled unsweetened tea beverage according to any one of aspects 1 to 3, which does not contain any flavorings. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a packaged, unsweetened tea beverage that has little astringency even after storage. The beverage of the present invention has little astringency and a fresh flavor even after storage. [Modes for carrying out the invention]

[0007] The present invention relates to a packaged unsweetened tea beverage. More specifically, it relates to a packaged unsweetened tea beverage comprising a fermented tea extract and an unfermented tea extract, wherein the theaflavin concentration is 0.05 to 0.20 mg / 100 ml, the non-polymerized catechin concentration is 5.0 to 50.0 mg / 100 ml, and the ratio of the non-polymerized catechin concentration to the tannin concentration is 0.40 or less.

[0008] (tea drink) This invention relates to a packaged unsweetened tea beverage. In the context of packaged unsweetened tea beverages, "tea beverage" refers to a beverage that uses the leaves of the tea plant (scientific name: Camellia sinensis) as the main ingredient and contains a tea extract obtained by extracting it with water or hot water. In particular, it refers to a beverage that uses a tea extract as the main ingredient and can generally be recognized as a "tea beverage." Therefore, the beverage of this invention refers to a beverage in which, in the ingredient labeling as indicated in accordance with the Food Labeling Standards (effective October 1, 2025), the first indication is related to tea or tea extract, such as "green tea," "black tea," "oolong tea," "gyokuro," "hojicha," or "Japanese black tea."

[0009] Tea leaves used as raw materials for tea extracts are generally classified into unfermented tea (green tea), semi-fermented tea (oolong tea, etc.), and fully fermented tea (black tea, etc.) according to the degree of enzymatic oxidation. In the present invention, "fermented tea" may be either semi-fermented tea or fully fermented tea, or it may contain both. The tea beverage of the present invention contains both an unfermented tea extract made from unfermented tea and a fermented tea extract made from fermented tea (semi-fermented tea and / or fully fermented tea).

[0010] Unfermented tea extracts are generally known as green tea (also called green tea extracts), and while not limited to these, examples include sencha, bancha, gyokuro, tencha, kamairicha, and hojicha. In the present invention, any of these can be used as the unfermented tea extract. Furthermore, two or more of these may be blended and used. Fermented tea extracts, as described above, may be semi-fermented tea extracts, fully fermented tea extracts, or blends thereof. An example of a semi-fermented tea extract is oolong tea (also called oolong tea extract). Oolong teas include brands such as Tieguanyin, Sezhong, Huangjin Gui, and Wuyi rock tea, and any of these can be used. An example of a fully fermented tea extract is black tea (also called black tea extract). Black teas come in various types depending on their origin and production method, such as Darjeeling, Assam, Sri Lankan, and Japanese black tea, and any of these can be used in the present invention, and two or more of these may be used in combination. Of the fermented tea extracts to be included in the tea beverage of the present invention, it is preferable from the viewpoint of flavor to include fully fermented tea extracts among semi-fermented tea extracts and fully fermented tea extracts, and it is particularly preferable to include black tea. Therefore, it is particularly preferable for the tea beverage of the present invention to include green tea extract and black tea extract, and it is most preferable to include only green tea extract and black tea extract as the tea extract.

[0011] When incorporating fermented tea extract and unfermented tea extract into the beverage of the present invention, an unfermented tea extract made from unfermented tea and a fermented tea extract made from fermented tea may be prepared separately, and both may be included in the beverage. Alternatively, a tea extract containing both unfermented tea extract and fermented tea extract may be obtained by blending unfermented tea and fermented tea in their leaf form and extracting the resulting mixture, and this may be included in the beverage.

[0012] In the beverage of the present invention, the content ratio of unfermented tea extract to fermented tea extract is not particularly limited, but the tea-derived solids (also called tea solids) are preferably 1:99 to 99:1, more preferably 5:95 to 95:5, even more preferably 10:90 to 90:10, and most preferably 20:80 to 40:60. Furthermore, it is preferable that the tea solids derived from fermented tea extract be present in greater quantities than the tea solids derived from unfermented tea extract. In this specification, tea solids refer to the Brix (refractometer reading for sugar) of the target tea extract.

[0013] (sugar-free drink) The beverage of the present invention is a sugar-free beverage. A sugar-free beverage is a beverage in which the concentration of sugars is less than 0.5 g / 100 ml, preferably less than 0.2 g / 100 ml, more preferably less than 0.1 g / 100 ml, and most preferably 0 g / 100 ml. Here, sugars refer to monosaccharides and disaccharides, but not sugar alcohols. The concentration of sugars can be measured by known methods, such as using high-performance liquid chromatography (HPLC).

[0014] Furthermore, it is preferable that the beverage of the present invention is not only sugar-free but also does not contain sweetening components such as high-intensity sweeteners or sugar alcohols. High-intensity sweeteners are non-carbohydrate sweeteners that are tens to tens of thousands of times sweeter than sugar, and specific examples include sucralose, acesulfame potassium, aspartame, stevia, monk fruit, neotame, advantame, saccharin, and glycyrrhizin. Sugar alcohols are carbohydrates to which hydrogen has been added to the carbonyl group, and specific examples of sweetening sugar alcohols include sorbitol, xylitol, maltitol, erythritol, lactitol, and reduced starch syrup.

[0015] (Packaged beverages) The tea beverage of the present invention is a sealed, packaged beverage. The container can be the same as that of general packaged beverages, such as a molded container mainly composed of polyethylene terephthalate (so-called polyethylene terephthalate (PET) bottle), a metal can, a paper container composited with metal foil or plastic film, or a glass bottle. When filling the container, heat sterilization is generally performed. Heat sterilization is acceptable as long as it complies with the standards of the Food Sanitation Act. For example, one method is to sterilize the prepared liquid at high temperature for a short time and then fill it into a storage container that has been sterilized under sterile conditions (UHT sterilization method), or to fill the prepared liquid into a storage container such as a can and then perform retort sterilization. In the case of UHT sterilization, heat sterilization is usually performed at 120-150°C for about 1-120 seconds, preferably at 130-145°C for about 30-120 seconds, and in the case of retort sterilization, heat sterilization is usually performed at 110-130°C for about 10-30 minutes, preferably at 120-125°C for about 10-20 minutes. For example, although not limited to this, it is preferable to perform heat sterilization at 121.1°C for 4 minutes or more (i.e., an F0 value of 4 or higher).

[0016] Among beverage products, there exist powdered beverage products that are made drinkable by dissolving the powder in water, hot water or the like. However, the beverage according to the present invention is not a powdered beverage product, but a beverage that is filled into containers in a liquid state and distributed. Although the beverage of the present invention may be a concentrated beverage that is consumed after dilution, it is preferably an RTD (Ready-to-drink) beverage that can be drunk directly after opening the container.

[0017] In the present specification, the "packaged sugar-free tea beverage" of the present invention may be simply referred to as "tea beverage", "beverage", "packaged tea beverage", "packaged beverage", "sugar-free beverage", "sugar-free tea beverage", etc.

[0018] (Theaflavin) The packaged sugar-free tea beverage of the present invention contains 0.05 to 0.20 mg / 100mL of theaflavin. Theaflavin has the chemical formula C 29 H 24 O 12 , which is a type of polyphenol. It is known to be generated during the fermentation process of green tea leaves when producing fermented tea. The concentration of theaflavin in a beverage can be measured by, for example, using liquid chromatography-mass spectrometry (LC / MS) as described in the Examples section. The concentration of theaflavin in the beverage of the present invention is more preferably 0.06 to 0.15 mg / 100mL, and still more preferably 0.07 to 0.10 mg / 100mL. The concentration of theaflavin in the packaged sugar-free tea beverage may be the concentration measured immediately after production of the beverage, or may be the concentration after one month of storage following production of the beverage. The storage conditions in this case refer to storage in the usual method specified according to the type of packaged beverage. For example, for normal temperature storage, it is one month of storage at normal temperature, and for refrigerated storage, it is one month of storage under refrigeration.

[0019] The tea beverage of the present invention comprises a fermented tea extract and an unfermented tea extract, and theaflavin may be derived from these tea extracts, particularly the fermented tea extract. Alternatively, it may comprise theaflavin added separately from the tea extracts.

[0020] (Non-polymerized catechins) The packaged sugar-free tea beverage of the present invention contains 5.0 to 50.0 mg / 100ml of non-polymerized catechins. In the present invention, the term "non-polymerized catechins" refers to catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate. When referring to the concentration of non-polymerized catechins, it means the sum of the concentrations of the above 8 compounds (namely, catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate). The concentration of non-polymerized catechins in a beverage can be measured using known methods such as, for example, HPLC or LC / MS. An example of a measurement method using the LC / MS method is described in the Examples section. The concentration of non-polymerized catechins in the beverage of the present invention is more preferably 5.5 to 40.0 mg / 100ml, and still more preferably 6.0 to 30.0 mg / 100ml. The concentration of non-polymerized catechins in the packaged sugar-free tea beverage may be the concentration measured immediately after production of the beverage, but is preferably the concentration after storage for one month from the production of the beverage. The storage conditions herein are storage under ordinary conditions specified according to the type of packaged beverage. For example, in the case of normal-temperature storage, it means storage at normal temperature for one month, and in the case of refrigerated storage, it means refrigerated storage for one month. It is known that the concentration of non-polymerized catechins in a beverage tends to decrease over time. When producing the beverage of the present invention, it is preferable to adjust the formulation such that non-polymerized catechins remain in the beverage at a concentration within the above range after one month of storage.

[0021] The tea beverage of the present invention comprises a fermented tea extract and a non-fermented tea extract, and the non-polymerized catechins may be derived from these tea extracts. Alternatively, the tea beverage may contain non-polymerized catechins added separately from the tea extracts.

[0022] (Ratio of the concentration of non-polymerized catechins to the concentration of tannins) In the bottled unsweetened tea beverage of the present invention, the ratio of the concentration of non-polymerized catechins to the concentration of tannins (i.e., concentration of non-polymerized catechins / concentration of tannins) (all units of concentration are mg / 100ml) is 0.40 or less. In the present invention, the "concentration of tannins" in the beverage refers to the concentration measured according to the method described in the "2.6 Tannins" section of the "Official Analytical Method for Tea" described in the Tea Research Institute Research Report, No. 6, pp. 167-172 (March 1970, Ministry of Agriculture and Forestry Tea Research Institute). The lower limit is preferably 0.10 or more, the above ratio is more preferably 0.10 to 0.35, and even more preferably 0.15 to 0.30. When the above ratio is within this range, a beverage with less astringency can be obtained even after storage. The concentration of tannins in the beverage may be the concentration measured immediately after the beverage is manufactured, but it is preferable that it be the concentration after storage for one month from the time of manufacture. The storage conditions in this case are those specified for the type of packaged beverage, using the usual storage methods. For example, if storage is at room temperature, it means storage at room temperature for one month; if refrigerated storage is required, it means storage in the refrigerator for one month.

[0023] The tea beverage of the present invention contains fermented tea extract and unfermented tea extract, and the tannin may be derived from these tea extracts. Alternatively, it may contain tannin added separately from the tea extract.

[0024] (Brix) The unsweetened, bottled tea beverage of the present invention has little astringency, a fresh aroma and flavor, and is a beverage that is easy to drink (high drinkability). From the viewpoint of taking advantage of the high drinkability of the beverage of the present invention, it is preferable that the Brix (refractometer reading for sugar, also called Bx) be relatively small. The Brix of the tea beverage of the present invention is preferably 0.60 or less when measured at 20°C. It may also be, for example, 0.50 or less, or 0.40 or less. The lower limit of Brix is ​​not particularly limited. For example, it may be 0.10 or more.

[0025] (Other ingredients) The beverage of the present invention may contain ingredients other than those described above, provided that they do not impair the effects of the present invention and do not lose their tea-like characteristics. Examples of such ingredients include pH adjusters and antioxidants. Examples of pH adjusters include baking soda and various carbonates. Examples of antioxidants include vitamin C.

[0026] Since ingredients such as fruit juice, alcohol, and carbon dioxide generally tend to impair the characteristics of a tea beverage, it is preferable that the beverage of the present invention does not contain fruit juice, is preferably a non-alcoholic beverage that does not contain alcohol, and is preferably a non-carbonated beverage that does not contain carbon dioxide. Furthermore, since dietary fiber such as indigestible dextrin tends to increase the Brix of tea beverages and generally slightly reduce drinkability (making it difficult to drink continuously), it is preferable that the beverage of the present invention does not contain dietary fiber such as indigestible dextrin that is added separately from the tea ingredients.

[0027] The tea beverage of the present invention has less astringency and a fresh flavor, and in order to make the most of the refreshing flavor inherent in tea, it is preferable that it does not contain any flavorings. While some tea beverages, such as milk tea and matcha milk, contain dairy components, the tea beverage of the present invention has less astringency and a fresh flavor. In order to maximize the refreshing flavor inherent in tea, it is preferable that it does not contain dairy components (i.e., components derived from animal milk such as cow's milk, and components derived from plant-based milk such as soy milk). [Examples]

[0028] The present invention will be described below based on examples, but the present invention is not limited to these examples. (Method for measuring the concentration of theaflavins in beverages) A 2g sample was taken, 2ml of 1mg / ml oxalic acid and methanol were added, and the mixture was sonicated for 5 minutes. After dilution as appropriate, the solution was filtered through a filter (pore size 0.45μm), and the theaflavin concentration was measured using LC / MS under the following conditions. • Column: ACQUITY BEH C18, φ2.1mm × 100mm, particle size 1.7μm Column temperature: 40°C Mobile phase: Mixture of 1% acetic acid and acetonitrile (77:23) ·Flow rate: 0.2ml / min • Ionization method: Electrospray (positive ion detection mode) ·Set mass number (m / z): 565.0 → 426.9.

[0029] (Method for measuring the concentration of non-polymerized catechins in beverages) Two g of the sample was taken, and two ml of oxalic acid at a concentration of 1 mg / ml and methanol were added. The mixture was then sonicated for five minutes. After dilution as appropriate, the solution was filtered through a filter (pore size 0.45 μm), and the concentration of non-polymerized catechin (total concentration of the eight compounds) was measured using LC / MS under the following conditions. • Column: InertSustain C18, φ2.1mm × 150mm, particle size 3μm Column temperature: 40°C Mobile phase: Mixture of 1% acetic acid and acetonitrile (89:11) ·Flow rate: 0.2ml / min • Ionization method: Electrospray (positive ion detection mode) ·Set mass number (m / z): Catechin, Epicatechin: 290.9 → 138.9 Gallocatechin, Epigallocatechin: 306.9 → 138.9 Epigallocatechin gallate, Gallocatechin gallate: 459.0 → 138.9 Epicatechin gallate, catechin gallate: 443.0 → 122.9.

[0030] (Method for measuring tannin concentration in beverages) The tannin concentration was measured according to the method described in section "2.6 Tannin" of "Official Analytical Methods for Tea" in the Tea Research Station Research Report, No. 6, pp. 167-172 (March 1970, Tea Research Station, Ministry of Agriculture and Forestry).

[0031] (Test Example 1) Unfermented tea extract (green tea extract A) was prepared by adding 22 times the mass ratio of hot water (90°C) to domestically produced first-flush green tea leaves and extracting for 3 minutes and 30 seconds. Similarly, fermented tea extract (black tea extract A) was prepared by adding 20 times the mass ratio of hot water (85°C) to Sri Lankan black tea leaves and extracting for 3 minutes. In the same manner, fermented tea extract (black tea extract B) was prepared by adding 22 times the mass ratio of hot water (90°C) to domestically produced black tea leaves and extracting for 2 minutes and 30 seconds. The green tea extract and black tea extract were blended according to the proportions shown in Table 1 and heat-sterilized. The heat-sterilized samples were filled into 50 ml PET bottles and sealed. After storing the sealed samples at room temperature for one month, they were opened, and the concentrations of theaflavins, non-polymerized catechins, and tannins were measured using the method described above, and Brix at 20°C was also measured. Furthermore, a sensory evaluation of the astringency of the beverages was conducted by a panel of six experts. The sensory evaluation involved each panel member assigning scores according to the following criteria, with the average score of all panel members being used as the final score. Drinkability (i.e., whether the drink was easy to drink) was also evaluated. The temperature of the samples used for evaluation was approximately 20°C. The results are shown in Table 1.

[0032] (Criteria for sensory evaluation of astringency) 0 points: It has an astringent taste and almost no fresh aroma. 1 point: I can detect a slight astringency, but I also sense a fresh aroma. Points 2: There is almost no astringency. A fresh aroma is noticeable.

[0033] [Table 1]

[0034] As shown in Table 1, many panelists detected an astringent taste in Sample 1, which consisted only of green tea extract, after one month of storage. Similarly, many panelists detected an astringent taste in Sample 2, which consisted only of black tea extract and had a high concentration of theaflavins, after one month of storage. Samples prior to one month of storage (samples immediately after heat sterilization and before filling into containers, adjusted to 5°C) were also tasted by six expert panelists, and all samples were evaluated as having almost no astringent taste. It can be seen that the astringent taste increased in Samples 1 and 2 during storage. On the other hand, Samples 3-6, which contained both green tea and black tea extracts, had theaflavin concentrations in the range of 0.05-0.20 mg / 100ml, non-polymerized catechin concentrations in the range of 5.0-50.0 mg / 100ml, and a non-polymerized catechin / tannin concentration ratio of 0.40 or less, exhibited less astringency. In particular, all six panelists rated samples 3 and 4 as having good drinkability. Sample 7, which contained both green tea and black tea extracts, had a low theaflavin concentration and a non-polymerized catechin / tannin ratio exceeding 0.40, and therefore showed little reduction in astringency.

[0035] (Test Example 2) Unfermented tea extract (green tea extract B) was prepared by adding 22 times the mass ratio of hot water (90°C) to domestically produced first-flush roasted tea leaves and extracting for 5 minutes. Similarly, unfermented tea extract (green tea extract C) was prepared by adding 22 times the mass ratio of hot water (90°C) to domestically produced autumn / winter bancha tea leaves and extracting for 3 minutes and 30 seconds. These, along with black tea extracts A and B prepared in Test Example 1, were blended according to the proportions shown in Table 2, heat-sterilized, and filled into 50ml PET bottles, which were then sealed. After storing the sealed samples at room temperature for one month, they were opened, and the concentrations of theaflavins, non-polymerized catechins, and tannins were measured, as in Test Example 1, and Brix at 20°C was also measured. Furthermore, a sensory evaluation of the astringency of the beverage was conducted by a panel of six experts, as in Test Example 1. The results are shown in Table 2.

[0036] [Table 2]

[0037] Similar to Test Example 1, all samples were evaluated as having almost no astringency before being stored for one month. On the other hand, many panels detected an astringency in samples 8 and 15, which consisted only of green tea extract, after one month of storage. In contrast, samples 9, 10, 13, and 14, which contained both green tea and black tea extracts, had theaflavin concentrations in the range of 0.05 to 0.20 mg / 100 ml, non-polymerized catechin concentrations in the range of 5.0 to 50.0 mg / 100 ml, and a non-polymerized catechin / tannin concentration ratio of 0.40 or less, exhibited little astringency. Furthermore, all six panelists evaluated samples 9, 10, 13, and 14 as having good drinkability. Sample 11, which contained both green tea extract and black tea extract, had a low theaflavin concentration; Sample 12 had a high theaflavin concentration; and Sample 16 had a high non-polymerized catechin concentration and a non-polymerized catechin concentration / tannin concentration ratio greater than 0.40, all of which showed little reduction in astringency.

Claims

1. It is a bottled unsweetened tea beverage, Contains fermented tea extract and unfermented tea extract. The theaflavin concentration is 0.05 to 0.20 mg / 100 ml. The concentration of non-polymerized catechins is 5.0 to 40.0 mg / 100 ml. The beverage in which the ratio of the concentration of non-polymerized catechins to the concentration of tannins is 0.40 or less.

2. The unsweetened, bottled tea beverage according to claim 1, wherein the fermented tea extract contains black tea extract.

3. A bottled unsweetened tea beverage according to claim 1 or 2, wherein the Brix is ​​0.60 or less.

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