JP7536992B1 - Packaged black tea beverage and its manufacturing method - Google Patents

Abstract

[Problem] The object of the present invention is to provide a packaged black tea beverage which contains milk protein and suppresses the gamey odor that occurs in unsweetened black tea beverages due to the milk protein, and a method for producing the same. [Solution] A packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, which is prepared so that the packaged black tea beverage further satisfies any one of the following conditions (a) to (c): (a) a hexanal concentration of 5 to 2000 ppb; (b) a geraniol concentration of 5 ppb or more; (c) a hexanal concentration of 5 to 2000 ppb and a geraniol concentration of 2 to 2000 ppb; [Selected Figure] None

Description

The present invention relates to a packaged black tea beverage and a method for producing the same. More specifically, the present invention relates to a packaged black tea beverage that contains milk protein and suppresses the gamey odor (hereinafter, also referred to simply as "gamey odor" in this specification) that occurs due to the milk protein in sugar-free black tea beverages (sugar concentration less than 0.5 g/100 mL), and a method for producing the same.

Milk tea is a black tea beverage containing dairy ingredients, generally prepared by mixing black tea leaf extract with milk or other dairy ingredients. In recent years, milk tea has been distributed as a packaged beverage in cans, plastic bottles, paper cartons, or other containers. Milk tea is one of the most popular tea beverages, both from the viewpoint of taste and health consciousness, due to the unique aroma and bitter and astringent taste of black tea, and the sweet taste of dairy ingredients such as milk.

On the other hand, in order to make these packaged beverages suitable for mass production, the extraction process must be carried out using industrial methods, and strong sterilization must be carried out to increase microbial stability so that they can withstand long-term storage. As a result, the industrial manufacturing and sterilization processes cause the aroma to dissipate and the flavor to deteriorate due to heating, making it difficult to obtain a product with a flavor that is fully satisfactory compared to tea brewed in a teapot at home or in a coffee shop.

On the other hand, hexanal is a type of chain aliphatic aldehyde, a substance represented by the chemical formula C ₆ H ₁₂ O, and is known to be the cause of the grassy aroma of soybeans and grass. Geraniol is a type of straight-chain monoterpenoid, a substance represented by the chemical formula C ₁₀ H ₁₈ O, and is known to have a rose-like aroma. Patent Document 1 discloses an oolong tea beverage in which the contents of hexanal and 2,4-heptadienal, which have an oxidized odor and a grassy aroma that impair the fresh flavor, are limited to a specified content (20.0 ppb or less, preferably 0 to 10.0 ppb).

On the other hand, in a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, it has not been previously known that the "animal odor" can be suppressed by preparing the packaged black tea beverage so that it further satisfies any one of the following conditions (a) to (c).
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;

JP 2016-140305 A

The object of the present invention is to provide a packaged black tea beverage that contains milk protein and suppresses the gamey odor that is caused by milk protein in unsweetened black tea beverages, and a method for producing the same.

The present inventors have conducted intensive research to solve the above problems, and as a result have found that in a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, the packaged black tea beverage can be prepared so that the packaged black tea beverage further satisfies any one of the following conditions (a) to (c), thereby suppressing the "animal odor" while maintaining the flavor harmony of the above-mentioned packaged black tea beverage:
The present invention has been completed.
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
Furthermore, because hexanal is an aroma component known to cause an unpleasant odor, it was unexpected by those skilled in the art that by preparing the above-mentioned packaged black tea beverage so as to satisfy any one of the above conditions (a) to (c), it is possible to suppress the above-mentioned gamey odor while maintaining the flavor harmony of the above-mentioned packaged black tea beverage.

That is, according to the present invention, the following inventions are provided.
(1) A packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, said packaged black tea beverage further satisfying any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
(2) The packaged black tea beverage according to (1) above, which contains one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, milk protein purified product, whey protein concentrate, whey protein purified product, casein protein concentrate, and casein protein purified product;
(3) A packaged black tea beverage according to the above (1) or (2), in which the ratio of the hexanal content (ppb) to the milk protein content (mass%) is 4.2 to 6670, or the ratio of the geraniol content (ppb) to the milk protein content (mass%) is 4.2 or more;
(4) A method for producing a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
(5) The method according to (4) above, wherein the packaged black tea beverage contains one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, milk protein purified product, whey protein concentrate, whey protein purified product, casein protein concentrate, and casein protein purified product;
(6) The method according to (4) or (5) above, in which the ratio of the hexanal content (ppb) to the milk protein content (mass%) in the packaged black tea beverage is 4.2 to 6670, or the ratio of the geraniol content (ppb) to the milk protein content (mass%) is 4.2 or more;
(7) A method for suppressing the gamey odor in a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
(8) The method according to (7) above, wherein the packaged black tea beverage contains one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, purified milk protein, whey protein concentrate, purified whey protein, casein protein concentrate, and purified casein protein;
(9) The method according to (7) or (8) above, wherein the ratio of the hexanal content (ppb) to the milk protein content (mass%) in the packaged black tea beverage is 4.2 to 6670, or the ratio of the geraniol content (ppb) to the milk protein content (mass%) is 4.2 or more;

The present invention provides a packaged black tea beverage that contains milk protein and suppresses the gamey odor that is caused by milk protein in unsweetened black tea beverages, as well as a method for producing the same.

The present invention relates to
[1] A packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, said packaged black tea beverage further satisfying any one of the following conditions (a) to (c) (hereinafter also referred to as "the black tea beverage of the present invention");
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
[2] A method for producing a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c) (hereinafter also referred to as the "production method of the present invention");
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
[3] A method for suppressing the gamey odor of a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c) (hereinafter also referred to as the "suppression method of the present invention");
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
etc.

(Tea drinks)
The black tea beverage of the present invention contains black tea extract and milk protein, but may or may not contain milk. When the black tea beverage contains milk, the milk content in the black tea beverage is not particularly limited, and may be 0.03 to 15% by mass, 0.07 to 15% by mass, 0.1 to 15% by mass, 0.2 to 12.5% by mass, 0.3 to 12% by mass, or 1 to 10% by mass. Since it is possible to set the sugar concentration to a low level in spite of the high milk protein content, the milk content is preferably 10% by mass or less, 9% by mass or less, 8% by mass or less, 7% by mass or less, 6% by mass or less, 5% by mass or less, 4% by mass or less, 3% by mass or less, 2% by mass or less, 1% by mass or less, 0.8% by mass or less, 0.6% by mass or less, 0.4% by mass or less, 0.2% by mass or less, 0.1% by mass or less, 0.07% by mass or less, or 0.03% by mass or less, and more preferably 0% by mass. These lower and upper limits can be combined in any combination. Generally, black tea beverages with a low milk content are less satisfying to drink compared to black tea beverages with a high milk content, but the addition of milk protein can compensate for this.

(Black tea extract)
The black tea beverage contains a black tea extract. In this specification, the term "black tea extract" refers to an extract obtained by subjecting black tea leaves to an extraction process. In addition, in this specification, the black tea extract includes the extract from black tea leaves (black tea extract) itself and processed products thereof (for example, black tea extract obtained by concentrating or powdering the black tea extract). The tannin concentration in the black tea beverage is not particularly limited as long as it is 10 mg/100 mL or more, and preferred examples include 10 mg/100 mL to 200 mg/100 mL, 20 mg/100 mL to 180 mg/100 mL, 20 mg/100 mL to 150 mg/100 mL, 30 mg/100 mL to 120 mg/100 mL, 40 mg/100 mL to 100 mg/100 mL, and 40 mg/100 mL to 80 mg/100 mL.

There are no particular limitations on the black tea leaves that can be used as the raw material for black tea extract, and examples include tea leaves obtained from the Chinese species (var. sinensis) of Camelliasinensis, the Assam species (var. assamica), or hybrids thereof, which are processed through a fermentation process. There are also no particular limitations on the tea season, shape of the tea leaves, place of origin, variety, grade, and fermentation conditions, and these can be set appropriately by those skilled in the art. In addition, there are no particular limitations on the conditions for extracting black tea leaves, such as the amount of tea leaves, amount of solvent, extraction temperature, and extraction time, and the conditions for extracting regular black tea leaves can be used.

(Milk Protein)
In this specification, "milk protein" refers to a protein derived from animal milk such as cow's milk, goat's milk, sheep's milk, etc., and for convenience, also includes milk peptides, which are hydrolysates of milk proteins. Specific examples of milk proteins include casein protein, whey protein, and hydrolysates thereof. Examples of the above whey proteins include albumin, lactoglobulin, lactoferrin, etc.

The milk protein content in the black tea beverage of the present invention is not particularly limited as long as it is 0.3% by mass or more, but from the viewpoint of a stronger animal odor and thus greater significance of the present invention, and from the viewpoint of the satisfying taste of the black tea beverage, the lower limit is preferably 0.33% by mass or more, 0.36% by mass or more, 0.39% by mass or more, or 0.6% by mass or more, and the upper limit is, for example, 2.0% by mass or less, 1.5% by mass or less, or 1.2% by mass or less. These lower and upper limits can be combined in any desired manner.

In the present invention, the milk protein concentration in the black tea beverage can be adjusted, for example, by adjusting the amount of milk protein or a milk protein-containing composition contained in the black tea beverage. Commercially available milk proteins and milk protein-containing compositions can be used. The milk protein-containing composition is not particularly limited as long as it contains milk protein, but for example, when adjusting the concentration of sugars to a certain concentration or less, it is preferable to use a milk protein-containing composition in which 40% by mass or more, preferably 60% by mass or more, more preferably 80% by mass or more of the dry mass is milk protein. Examples of milk proteins or milk protein-containing compositions include one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, milk protein purified product, whey protein concentrate, whey protein purified product, casein protein concentrate, and casein protein purified product. In view of the high milk protein concentration, one or more selected from the group consisting of milk protein concentrate (MPC), milk protein purified product, whey protein concentrate, whey protein purified product, casein protein concentrate, and casein protein purified product are preferred.

The amount of milk protein in black tea beverages can be measured by known methods, such as the Kjeldahl method, the Dumas method, or modified or improved versions of these methods (see, for example, "Explanation of the Analysis Manual for the 5th Edition of the Standard Tables of Food Composition in Japan" (edited by Japan Food Research Center, Chuohoki Publishing)). In addition, commercially available products can be used as appropriate for the decomposition accelerator and other reagents used in the Kjeldahl method. Commercially available measuring instruments can also be used.

(Hexanal)
The black tea beverage of the present invention, which satisfies the above condition (a) or (c), contains hexanal at a specific concentration. This makes it possible to suppress the animal odor caused by milk protein in a black tea beverage having a milk protein content of 0.3 mass% or more and a sugar content of less than 0.5 g/100 mL. Hexanal is a type of chain aliphatic aldehyde and is a substance represented by the chemical formula C ₆ H ₁₂ O. The concentration of hexanal in the black tea beverage of the present invention in an embodiment that satisfies the above conditions (a) or (c) can be 5 to 2000 ppb, and the lower limit can be 10 ppb or more, 20 ppb or more, preferably 50 ppb or more, more preferably 100 ppb or more, 500 ppb or more, from the viewpoint of obtaining a greater suppressive effect against animal odor, and the upper limit can be 2000 ppb or less, preferably 1000 ppb or less, from the viewpoint of preventing the flavor derived from hexanal from becoming too strong. These lower limit and upper limit values can be arbitrarily combined, and the lower limit and upper limit values of hexanal under the condition (a) and the lower limit and upper limit values of hexanal under the condition (c) can be different numerical values.

In the black tea beverage of the present invention that satisfies the above condition (a) or (c), the ratio of the hexanal concentration (ppb) to the milk protein concentration (mass%) (hexanal concentration/milk protein concentration) is not particularly limited, but is, for example, 4.2 to 6670, preferably 8.3 to 3330, and more preferably 16.7 to 1670.

The concentration of hexanal in the black tea beverage of the present invention can be measured by a known GC-MS method. However, in the present invention, it is preferable to use a highly polar column (DB-WaxUI, manufactured by Agilent Technologies) as the column, a solid-phase microextraction method (SPME-Arrow Carbon WR/PDMS, manufactured by CTC Analytics) as the extraction method, and a high-resolution mass spectrometer (Q Exactive GC Orbitrap, manufactured by Thermo Fisher Scientific) as the detector.

The hexanal used in the present invention in an embodiment that satisfies the above conditions (a) or (c) is not particularly limited, and may be a crude product as well as a refined product. For example, it may be a natural product containing hexanal or a processed product thereof (such as a plant extract, essential oil, fermented plant product, or a concentrate thereof). More specific examples include flavorings containing hexanal, as well as extracts. The use of a flavoring containing hexanal is a preferred example, since only a small amount of the raw material needs to be added to the black tea beverage.

(Geraniol)
The black tea beverage of the present invention, which satisfies the above condition (b) or (c), contains geraniol, which makes it possible to suppress the gamey odor caused by milk protein in a black tea beverage having a milk protein content of 0.3 mass% or more and a sugar content of less than 0.5 _g /100 mL. Geraniol is a type of linear monoterpenoid and is a substance represented by the chemical formula _C10H18O .
The concentration of geraniol in the black tea beverage of the present invention in an embodiment that satisfies the above condition (b) can be 5 ppb or more, 10 ppb or more, and the lower limit can be, from the viewpoint of obtaining a greater suppressive effect against animal odor, preferably 20 ppb or more, more preferably 50 ppb or more, 100 ppb or more, and even more preferably 500 ppb or more, and the upper limit is not particularly limited, but can be, for example, 10000 ppb or less, 9000 ppb or less, 8000 ppb or less, 7000 ppb or less, 6000 ppb or less, or 5000 ppb or less when controlling the degree of flavor derived from geraniol. These lower limit and upper limit values can be combined arbitrarily.
The concentration of geraniol in the black tea beverage of the present invention in an embodiment that satisfies the above condition (c) can be 2 to 2000 ppb, with the lower limit being preferably 5 ppb or more, more preferably 10 ppb or more, even more preferably 20 ppb or more, even more preferably 50 ppb or more, and more preferably 100 ppb or more, from the viewpoint of obtaining a greater suppressive effect against animal odor, and the upper limit being 2000 ppb or less, preferably 1000 ppb or less, from the viewpoint of preventing the flavor derived from geraniol from becoming too strong. These lower and upper limits can be combined in any desired manner.
Furthermore, the lower limit value of geraniol under the condition (b) (and the upper limit value, if an upper limit value is set) and the lower limit value and the upper limit value of geraniol under the condition (c) may be different numerical values.

In the black tea beverage of the present invention that satisfies the above condition (b) or (c), the ratio of the geraniol concentration (ppb) to the milk protein concentration (mass%) (geraniol concentration/milk protein concentration) is not particularly limited, but may be, for example, 4.2 or more, preferably 4.2 to 6670, more preferably 8.3 to 3330, and even more preferably 16.7 to 1670.

The concentration of geraniol in the black tea beverage of the present invention can be measured by a known GC-MS method. However, in the present invention, it is preferable to use a highly polar column (DB-WaxUI, manufactured by Agilent Technologies) as the column, a solid-phase microextraction method (SPME-Arrow Carbon WR/PDMS, manufactured by CTC Analytics) as the extraction method, and a high-resolution mass spectrometer (Q Exactive GC Orbitrap, manufactured by Thermo Fisher Scientific) as the detector.

The geraniol used in the present invention in an embodiment that satisfies the above condition (b) or (c) is not particularly limited, and may be a crude product as well as a refined product. For example, it may be a natural product containing geraniol or a processed product thereof (such as a plant extract, essential oil, fermented plant product, or a concentrate thereof). More specific examples include flavorings containing geraniol, as well as extracts. A preferred example is the use of a flavoring containing geraniol, since only a small amount of the raw material is required to be added to the black tea beverage.

(Optional ingredients)
The black tea beverage of the present invention may or may not contain one or more of the following, for example: acidulant, colorant, sweetener, antioxidant (vitamin C, etc.), preservative, thickening stabilizer, emulsifier, vegetable oil, and pH adjuster (baking soda, etc.) The black tea beverage of the present invention may or may not contain soy milk.

Examples of the above-mentioned "sweetener" include crystalline sugars such as monosaccharides such as fructose, glucose, tagatose, arabinose, etc., disaccharides such as lactose, trehalose, maltose, sucrose, etc., and monosaccharides and disaccharides in powdered starch syrup; oligosaccharides such as maltooligosaccharides and galactooligosaccharides; non-crystalline sugars such as starch syrup and isomerized liquid sugar (e.g., fructose glucose liquid sugar); sugar alcohols such as maltitol, lactitol, sorbitol, mannitol, xylitol, erythritol; and high-intensity sweeteners such as sucralose, stevia, licorice extract, thaumatin, glycyrrhizin, saccharin, aspartame, and acesulfame K. From the viewpoint of natural sweetness, sugars (crystalline sugars and non-crystalline sugars) are preferred, and from the viewpoint of low calorie content, sugar alcohols and high-intensity sweeteners are preferred. When a sweetener is used, the concentration of the sweetener in the beverage of the present invention is not particularly limited, but when the sweetener is a sugar, examples of the concentration include less than 0.5 g/100 mL, 0.4% by mass or less, 0.05 to 0.4% by mass, 0.1 to 0.4% by mass, and 0.1 to 0.35% by mass. If the sugar concentration (including lactose contained in milk) is less than 0.5 g/100 mL, it can be labeled as "sugar-free." In addition, the sugar in this specification also includes lactose contained in milk when milk is blended, and the sugar concentration in this specification also takes such lactose into consideration. In addition, when the sweetener is a sugar alcohol or a high-intensity sweetener, examples of the concentration include a sweetness of less than 0.5% by mass, 0.4% by mass or less, 0.05 to 0.4% by mass, 0.1 to 0.4% by mass, and 0.1 to 0.35% by mass in terms of sucrose. In addition, the sweetness in this specification may be a sweetness taking into account sugar alcohols and/or high-intensity sweeteners, or may further be a sweetness taking into account sugars. Note that when the sugar concentration is less than 0.5 g/100 mL or the sweetness in terms of sucrose is less than 0.5% by mass, the animal odor is more noticeable than when the sugar concentration is high or the sweetness is high, so the significance of the present invention is greater.

(Black tea beverage of the present invention)
The black tea beverage of the present invention is a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, and other than satisfying any one of the following conditions (a) to (c), there is no particular difference between the manufacturing raw materials used, the manufacturing method, and the manufacturing conditions and those of a conventional packaged black tea beverage.
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;
The timing of adding "hexanal", "geraniol", or "hexanal and geraniol" may be either before or after heat sterilization, but is preferably before heat sterilization. The method and conditions for heat sterilization may be the same as those normally used for beverages such as packaged beverages.

The beverage of the present invention is a packaged beverage. Examples of such containers include plastic bottle containers such as PET bottles, polypropylene bottles, and polyvinyl chloride bottles; glass bottles; cans; and paper containers.

(Production method of the present invention)
The manufacturing method of the present invention is not particularly limited as long as it is a manufacturing method for a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is further prepared so as to satisfy any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;

The black tea beverage of the present invention is a method for producing a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, and can be produced by a general method for producing packaged black tea beverages, except that the packaged black tea beverage is further prepared to satisfy any one of the above conditions (a) to (c). General methods for producing packaged black tea beverages are known, and for example, a black tea beverage can be produced by preparing a black tea extract, and then going through a blending process, a filling process, and a heat sterilization process. In producing the black tea beverage of the present invention, the above-mentioned optional ingredients may be added, and there is no particular restriction on the timing of adding these optional ingredients.

In the present invention, the method of "preparing the black tea beverage so that the hexanal concentration is 5 to 2000 ppb" includes a method of adding hexanal or a hexanal-containing composition to the black tea beverage at any stage of the manufacturing process so that the hexanal concentration in the black tea beverage of the present invention is 5 to 2000 ppb, for example, a method of adding hexanal or a hexanal-containing composition to a black tea extract containing milk proteins.

In the present invention, the method of "preparing the geraniol content to be 5 ppb or more" or the method of "preparing the geraniol content to be 2 to 2000 ppb" include a method of adding geraniol or a geraniol-containing composition to the black tea beverage of the present invention at any stage of the production process so that the geraniol content is 5 ppb or more or 2 to 2000 ppb, for example, a method of adding geraniol or a geraniol-containing composition to a black tea extract containing milk proteins.

In the manufacturing method of the present invention, optional ingredients may be further contained, for example, one or more of acidulants, colorants, sweeteners, antioxidants (vitamin C, etc.), preservatives, thickening stabilizers, emulsifiers, vegetable oils and fats, and pH adjusters (such as baking soda). In addition, in the manufacturing method of the present invention, soy milk may be contained, but it is not necessary. In addition, in the manufacturing method of the present invention, the order in which the manufacturing ingredients are contained is not particularly limited, as long as the beverage of the present invention can be produced. After preparing a liquid in which the manufacturing ingredients are mixed, the liquid can be filled into a container and sealed to obtain the beverage of the present invention.

(Heat sterilization)
The manufacturing method of the present invention preferably includes a step of heat sterilizing the black tea beverage. As the heat sterilization method, a normal heat sterilization method for packaged black tea beverages can be used without any particular restrictions. For example, in the case of metal cans where heat sterilization can be performed after filling, sterilization treatment can be performed under sterilization conditions stipulated in the Food Sanitation Act. In addition, for PET bottles, paper containers, and other containers where retort sterilization cannot be performed, a method can be adopted in which the beverage is sterilized under the same sterilization conditions as above, for example, by using a plate-type heat exchanger, etc., before filling, and then cooled to a certain temperature and filled into a sterilized container.

(Inhibition method of the present invention)
The suppression method of the present invention is not particularly limited as long as it is a method for suppressing gamey odor in a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb;

The method for preparing a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL so as to further satisfy any one of the above conditions (a) to (c) can be the same as the method described above in (Production method of the present invention).

(Packaged black tea beverage with reduced animal odor)
The packaged black tea beverage of the present invention is a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, and in which an animal odor is suppressed (also referred to simply as a "packaged black tea beverage with suppressed animal odor" in this specification). Such an "animal odor" is an off-flavor that is particularly problematic when a black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL is heat sterilized, and the "animal odor" in the present invention means a sulfur odor, milky odor, and/or powdery odor that appears after the middle note (the aroma felt following the top note, which is the beginning of the aroma).

In this specification, a packaged black tea beverage with "suppressed gamey odor" is a beverage in which gamey odor is suppressed compared to a beverage (hereinafter also referred to as "control beverage") produced using the same ingredients and the same method to give the same final concentration, except that the hexanal concentration is less than 2 ppb (preferably 1 ppb or less) and the geraniol concentration is less than 2 ppb (preferably 1 ppb or less). Whether gamey odor is suppressed in a certain black tea beverage may be determined by, for example, taking the average of the evaluations of multiple panelists, using the gamey odor in the control beverage as the standard.

(Packaged black tea beverage with a harmonious flavor)
The beverage of the present invention is preferably a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, and has a harmonious flavor as a packaged black tea beverage. In the present invention, "flavor as a packaged black tea beverage having a milk protein concentration of 0.3% by mass or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL" means the flavor of black tea in such a packaged black tea beverage, and such a harmonious flavor means that such a flavor is maintained. Whether such a flavor is maintained in a certain black tea beverage can be easily and clearly determined by a panel, and preferably the average of the evaluations of multiple panels can be adopted as the degree of flavor harmony. Examples of packaged black tea beverages that do not retain the "flavor of a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL" include packaged black tea beverages in which the off-flavors derived from any of the ingredients are so excessive that the flavor of the black tea beverage is no longer harmonious, and more specifically, examples of packaged black tea beverages include packaged black tea beverages with a hexanal concentration of 5000 ppb or more and packaged black tea beverages with a geraniol concentration of 5000 ppb or more.

In this specification, unless otherwise specified, % and ratios refer to % by mass.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

Test 1. [Effect of milk protein concentration in black tea beverages on animal odor, etc.]
The following experiment was carried out to investigate the effect of the milk protein concentration in a black tea beverage on the level of gamey odor and other odors resulting from milk proteins.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorption method) described in "Explanation of the Japanese Food Standard Composition Analysis Manual, 5th Edition" edited by Japan Food Research Laboratories (edited by Japan Food Research Laboratories, Chuohoki, July 2001, p. 252). Sodium L-ascorbate (0.04% by mass), milk protein (milk protein concentrate: MPC), and milk (6.0% by mass) were added to the black tea extract so as to obtain the concentrations shown in Table 2, and then sodium bicarbonate (sodium bicarbonate) was added to adjust the pH to 6.8. The mixture was then filled into a container and retort sterilized (heated and pressurized sterilized) to prepare each of the sample beverages of Test Examples 2 to 6. In addition, the sample beverage of Test Example 1, which does not contain the above-mentioned milk protein (MPC), and Test Example 7, which does not contain the above-mentioned milk, were also prepared.
In addition, since the blended milk also contains 3.3% by mass of milk protein, the milk protein concentration in the sample beverages of Test Examples 2 to 6 is higher than the blended milk protein (MPC) concentration. In addition, lactose is contained in both milk and milk protein (MPC), with the lactose concentration in milk being approximately 4.8% by mass and the lactose concentration in the blended milk protein (MPC) being approximately 10% by mass. In addition, the tannin concentration in each sample beverage in Table 2 is 60 mg/100 mL.

(2. Sensory Evaluation Test)
A sensory evaluation test was conducted by five trained expert panelists on the level of "animal odor" in the sample beverages of Test Examples 2 to 6 compared with the sample beverage of Test Example 1, using the five-point evaluation criteria shown in Table 1 below. The difference in the level of animal odor between 1 point and 2 points, between 2 points and 3 points, between 3 points and 4 points, and between 4 points and 5 points were all set to the same level. The level of animal odor in the sample beverages of each Test Example was evaluated by rounding the average evaluation score of each panel to one decimal place. It should be noted that if the evaluation of the level of animal odor in the sample beverage is, for example, 2.0 points or more, it can be evaluated that there is an issue with animal odor.

The results of the sensory evaluation test for the sample beverages of Test Examples 1 to 6 are shown in Table 2.

The results in Table 2 show that when the milk protein concentration in the black tea beverage is 0.3% by mass or more, the problem of gamey odor occurs, and the level of gamey odor tends to increase depending on the milk protein concentration. It was also shown that this gamey odor is an issue even when milk protein (MPC) is added without milk (Test Example 7).

Test 2. [Effect of hexanal on animal odor 1]
The effect of hexanal on animal odor was investigated by the following experiment.

1. Preparation of black tea extract
The black tea leaves were placed in 90°C hot water and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorbance method) described in "Explanation of the 5th Edition of the Japanese Food Standard Composition Analysis Manual" (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252) compiled by Japan Food Research Center. Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), and hexanal were added to the black tea extract so as to obtain the concentrations shown in Tables 5 and 6, and then sodium bicarbonate (sodium bicarbonate) was added so as to obtain a pH of 6.8, and the mixture was filled into a container and subjected to retort sterilization (heated and pressurized sterilization) to prepare each of the sample beverages of Test Examples 8 to 17. In addition, as a control beverage, the sample beverage of Test Example 4 to which hexanal was not added was also prepared. The tannin concentration in each of the sample beverages of Tables 5 and 6 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
A sensory evaluation test was conducted by five trained expert panelists on the degree of suppression of "animal odor" in the sample beverages of Test Examples 8 to 17 compared with the sample beverage of Test Example 4, which is a control beverage, using the five-level evaluation criteria shown in Table 3 below. The difference in the degree of suppression of animal odor between 1 point and 2 points, the difference in the degree of suppression of animal odor between 2 points and 3 points, the difference in the degree of suppression of animal odor between 3 points and 4 points, and the difference in the degree of suppression of animal odor between 4 points and 5 points were each set to the same degree. In addition, the average value of the evaluation points of each panel was rounded to the first decimal place to evaluate the degree of suppression of animal odor in the sample beverages of each Test Example. The standard deviation of the evaluation points of each panel for each sample beverage was 0.55 or less for all sample beverages. It can be evaluated that suppression of animal odor was observed when the evaluation of the degree of suppression of "animal odor" in the sample beverage is, for example, 2.0 points or more.

In addition, a sensory evaluation test was conducted by five trained expert panelists on the degree of flavor harmony of the sample beverages of Test Examples 4 and 8 to 17 as packaged black tea beverages (specifically, packaged black tea beverages with a milk protein content of 0.3% by mass or more, a tannin content of 10 mg/100 mL or more, and a sugar content of less than 0.5 g/100 mL) using the five-level evaluation criteria shown in Table 4 below. The difference in the degree of flavor harmony between 1 point and 2 points, between 2 points and 3 points, between 3 points and 4 points, and between 4 points and 5 points were all set to the same level. The average value of the evaluation scores of each panel was rounded to one decimal place to evaluate the degree of flavor harmony in the sample beverages of each Test Example. The standard deviation of the evaluation scores of each panel for each sample beverage was 0.55 or less for all sample beverages. If the sample beverage's "flavor harmony" rating is, for example, 1.5 points or higher, it can be evaluated as being within the acceptable range for a packaged black tea beverage containing milk protein.

The results of the sensory evaluation test for the sample beverages of Test Examples 4 and 8 to 17 are shown in Tables 5 and 6.

From the results of Tables 5 and 6, when the concentration of hexanal was 5 ppb or more, the degree of suppression of the animal odor was evaluated as 2.0 or more, and the degree of suppression of the animal odor tended to increase depending on the concentration of hexanal. On the other hand, when the concentration of hexanal was 5000 ppb (Test Example 17), the animal odor was significantly suppressed, but the flavor of hexanal was too strong, and the flavor balance of a black tea beverage was not achieved (1.0). From these findings, it was shown that the hexanal concentration in the black tea beverage of the present invention is preferably 5 to 2000 ppb, 10 to 2000 ppb, 20 to 2000 ppb, 50 to 2000 ppb, 100 to 2000 ppb, 5 to 1000 ppb, 10 to 1000 ppb, 20 to 1000 ppb, 50 to 1000 ppb, 100 to 1000 ppb, etc., from the viewpoint of a balance between suppressing the animal odor and maintaining the harmony of the flavor.

Test 3. [Effect of hexanal on animal odor 2]
The effect of hexanal on gamey odor was investigated in the following experiment when the milk protein concentration was lower (0.3% by mass) and higher (1.2% by mass) than in the experiment in Test 2.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorbance method) described in "Explanation of the 5th Edition of the Japanese Food Standard Composition Analysis Manual" edited by Japan Food Research Center (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252). Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), and hexanal were added to the black tea extracts to give concentrations shown in Tables 7 and 8, and sodium bicarbonate (sodium bicarbonate) was added to give a pH of 6.8, which was then filled into a container and subjected to retort sterilization (heated and pressurized sterilization) to prepare each of the sample beverages of Test Examples 18 to 23. In addition, as control beverages, the sample beverage of Test Example 2 (total milk protein concentration of 0.3% by mass) to which hexanal was not added, and the sample beverage of Test Example 6 (total milk protein concentration of 1.2% by mass) were also prepared. The tannin concentration in each sample beverage in Tables 7 and 8 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In Table 7, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 18 to 20 was evaluated in comparison with the sample beverage of Test Example 2, which is a control beverage, and in Table 8, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 21 to 23 was evaluated in comparison with the sample beverage of Test Example 6, which is a control beverage.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for the sample beverages of Test Examples 18 to 20 are shown in Table 7, and the results of the sensory evaluation test for the sample beverages of Test Examples 21 to 23 are shown in Table 8.

The results in Tables 7 and 8 show that regardless of whether the milk protein concentration is low (0.3% by mass) or high (1.2% by mass), when the hexanal concentration is in the range of 5 to 2000 ppb, the flavor harmony is maintained while the gamey odor is suppressed.

Test 4. [Effect of geraniol on animal odor 1]
The effect of geraniol on animal odor was investigated by the following experiment.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorbance method) described in "Explanation of the 5th Edition of the Japanese Food Standard Composition Analysis Manual" (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252), edited by Japan Food Research Center. Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), and geraniol were added to the black tea extract so as to obtain the concentrations shown in Tables 9 and 10, and then sodium bicarbonate (sodium bicarbonate) was added to the black tea extract so as to obtain a pH of 6.8. The resulting mixture was then filled into a container and retort sterilized (heated and pressurized sterilized) to prepare each of the sample beverages of Test Examples 24 to 33. In addition, the sample beverage of Test Example 4 to which geraniol was not added was also prepared as a control beverage. The tannin concentration in each of the sample beverages of Tables 9 and 10 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In addition, in Tables 9 and 10, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 24 to 33 was evaluated in comparison with the sample beverage of Test Example 4, which is a control beverage.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for the sample beverages of Test Examples 4 and 24 to 29 are shown in Table 9, and the results of the sensory evaluation test for the sample beverages of Test Examples 30 to 33 are shown in Table 10.

From the results of Tables 9 and 10, when the concentration of geraniol contained is 5 ppb or more, the evaluation of the degree of suppression of the animal odor is 2.0 or more, and it was shown that the degree of suppression of the animal odor tends to increase depending on the concentration of geraniol contained. These results show that the concentration of geraniol in the black tea beverage of the present invention can be 5 ppb or more.

Test 5. [Effect of geraniol on animal odor 2]
The following experiment was carried out to investigate the effect of geraniol on gamey odor when the milk protein concentration was lower (0.3% by mass) and higher (1.2% by mass) than in the experiment in Test 2.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate spectrophotometric method) described in "Explanation of the Japanese Food Standard Composition Analysis Manual, 5th Edition" edited by Japan Food Research Center (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252). Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), and geraniol were added to the black tea extracts to achieve the concentrations shown in Tables 11 and 12, and then sodium bicarbonate (sodium bicarbonate) was added to adjust the pH to 6.8. The mixture was then filled into a container and retort sterilized (heated and pressurized sterilized) to prepare the sample beverages of Test Examples 34 to 39. In addition, as control beverages, the sample beverage of Test Example 2 (total milk protein concentration of 0.3% by mass) to which geraniol was not added, and the sample beverage of Test Example 6 (total milk protein concentration of 1.2% by mass) were also prepared. The tannin concentration in each of the sample beverages in Tables 11 and 12 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In Table 11, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 34 to 36 was evaluated in comparison with the sample beverage of Test Example 2, which is a control beverage, and in Table 12, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 37 to 39 was evaluated in comparison with the sample beverage of Test Example 6, which is a control beverage.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for the sample beverages of Test Examples 2 and 34 to 36 are shown in Table 11, and the results of the sensory evaluation test for the sample beverages of Test Examples 6 and 37 to 39 are shown in Table 12.

The results in Tables 11 and 12 show that regardless of whether the milk protein concentration is low (0.3% by mass) or high (1.2% by mass), when the geraniol concentration is in the range of, for example, 5 to 2000 ppb, the flavor harmony is maintained while the gamey odor is suppressed.

Test 6. [Effect of combined use of hexanal and geraniol on animal odor 1]
The effect of using hexanal and geraniol in combination on animal odor was investigated in the following experiment.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorbance method) described in "Explanation of the 5th Edition of the Japanese Food Standard Composition Analysis Manual" (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252), edited by Japan Food Research Center. Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), hexanal, and geraniol were added to the black tea extracts to the concentrations shown in Tables 13 and 14, and then sodium bicarbonate (sodium bicarbonate) was added to the black tea extracts to adjust the pH to 6.8, and the resulting mixture was filled into a container and subjected to retort sterilization (heated and pressurized sterilization) to prepare each of the sample beverages of Test Examples 40 to 49. In addition, as a control beverage, the sample beverage of Test Example 4 to which neither hexanal nor geraniol was added was also prepared. A sample beverage of Test Example 12 was also prepared in which hexanal was added but no geraniol was added. The tannin concentration in each sample beverage in Tables 13 and 14 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In addition, in Tables 13 and 14, the degree of suppression of the "animal odor" was evaluated in the sample beverages of Test Examples 12 and 40 to 49 compared with the sample beverage of Test Example 4, which is a control beverage.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for the sample beverages of Test Examples 4, 12, and 40 to 44 are shown in Table 13, and the results of the sensory evaluation test for the sample beverages of Test Examples 45 to 49 are shown in Table 14.

The results of Tables 13 and 14 show that even when geraniol is used in combination with hexanal, the effect of suppressing the animal odor is obtained. In addition, when geraniol is used in combination with hexanal, when the concentration of geraniol is 10 ppb or more, the effect of suppressing the animal odor is greater than when hexanal is used alone. In addition, when geraniol is used in combination with hexanal, the degree of suppression of the animal odor tends to increase depending on the concentration of geraniol. On the other hand, when the concentration of hexanal is 50 ppb and the concentration of geraniol is 5000 ppb (Test Example 49), the animal odor was significantly suppressed, but the flavor due to the combination of hexanal and geraniol was too strong, and the flavor harmony of the black tea beverage was not achieved ("1.3"). From these findings, it was shown that when geraniol is used in combination with hexanal in the black tea beverage of the present invention, the geraniol concentration is preferably 2 to 2000 ppb, 5 to 2000 ppb, 10 to 2000 ppb, 20 to 2000 ppb, 50 to 2000 ppb, 100 to 2000 ppb, 2 to 1000 ppb, 5 to 1000 ppb, 10 to 1000 ppb, 20 to 1000 ppb, 50 to 1000 ppb, 100 to 1000 ppb, etc., from the viewpoint of a balance between suppressing the animal odor and maintaining the harmony of the flavor.

Test 7. [Effect of combined use of hexanal and geraniol on animal odor 2]
The following experiment was conducted to investigate the effect of using hexanal and geraniol in combination on gamey odor when the milk protein concentration was lower (0.3% by mass) and higher (1.2% by mass) than in the experiment in Test 2.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorption method) described in "Explanation of the Japanese Food Standard Composition Analysis Manual, 5th Edition" edited by Japan Food Research Center (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252). Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), hexanal, and geraniol were added to the black tea extracts to the concentrations shown in Tables 15 and 16, and then sodium bicarbonate (sodium bicarbonate) was added to adjust the pH to 6.8. The mixture was then filled into a container and retort sterilized (heated and pressurized sterilized) to prepare each of the sample beverages of Test Examples 50 to 55. In addition, as control beverages, the sample beverage of Test Example 2 (total milk protein concentration of 0.3% by mass) to which hexanal was not added, and the sample beverage of Test Example 6 (total milk protein concentration of 1.2% by mass) were also prepared. The tannin concentration in each sample beverage in Tables 15 and 16 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In Table 15, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 50 to 52 was evaluated in comparison with the sample beverage of Test Example 2, which is a control beverage, and in Table 16, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 53 to 55 was evaluated in comparison with the sample beverage of Test Example 6, which is a control beverage.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for sample beverages of Test Examples 2 and 50 to 52 are shown in Table 15, and the results of the sensory evaluation test for sample beverages of Test Examples 6 and 53 to 55 are shown in Table 16.

The results in Tables 15 and 16 show that when geraniol is used in combination with hexanal, the flavor harmony is maintained while the gamey odor is suppressed, regardless of whether the milk protein concentration is low (0.3% by mass) or high (1.2% by mass).

Test 8. [Effect of combined use of hexanal and geraniol on animal odor 3]
The following experiment was carried out to examine whether an effect of suppressing animal odor could be obtained even when hexanal was 5 ppb or 2000 ppb and geraniol was 5 ppb or 2000 ppb.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate absorbance method) described in "Explanation of the 5th Edition of the Japanese Food Standard Composition Analysis Manual" edited by Japan Food Research Center (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252). Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), hexanal, and geraniol were added to the black tea extract so as to obtain the concentrations shown in Table 17, and then sodium bicarbonate (sodium bicarbonate) was added to the black tea extract so as to obtain a pH of 6.8. The resulting mixture was then filled into a container and retort sterilized (heated and pressurized sterilized) to prepare each of the sample beverages of Test Examples 56 to 59. In addition, as a control beverage, the sample beverage of Test Example 4 to which neither hexanal nor geraniol was added was also prepared. The tannin concentration in each sample beverage in Table 17 was 60 mg/100 mL.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In addition, in Table 17, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 56 to 59 was evaluated in comparison with the sample beverage of Test Example 4, which is a control beverage.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for sample beverages of Test Examples 4 and 56 to 59 are shown in Table 17.

The results in Table 17 show that even when hexanal is 5 ppb or 2000 ppb and geraniol is 5 ppb or 2000 ppb, the flavor harmony is maintained while the gamey odor is suppressed.

Test 9. [Effect of tannin concentration on gamey odor]
The effect of tannin concentration on gamey odor was investigated by the following experiment.

1. Preparation of black tea extract
The black tea leaves were placed in hot water at 90°C and extracted for 6 minutes, followed by solid-liquid separation to prepare black tea extracts. The tannin values of these black tea extracts were measured by the official method (ferric tartrate spectrophotometric method) described in "Explanation of the 5th Edition of the Japanese Food Standard Composition Analysis Manual" edited by Japan Food Research Center (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252). Sodium L-ascorbate (0.04% by mass), milk protein (MPC), milk (6.0% by mass), and hexanal were added to the black tea extracts to give concentrations shown in Table 18, and then sodium bicarbonate (sodium bicarbonate) was added to give a pH of 6.8. The mixture was then filled into a container and retort sterilized (heated and pressurized sterilized) to prepare the sample beverages of Test Examples 12, 60 to 63.
For Test Examples 44, and 64 to 67, each sample beverage was prepared in the same manner except that geraniol was also added (Table 19).
In addition, the sample beverages of Test Examples 28, and 68 to 70 were prepared in the same manner as in the preparation of the sample beverages of Test Examples 12, and 60 to 63, except that geraniol was used instead of hexanal (Table 20).
The tannin concentrations in Tables 18 to 20 are the concentrations in the sample beverages.

(2. Sensory Evaluation Test)
The degree of suppression of the "animal odor" was evaluated in the same manner as in the sensory evaluation test in Test 2. In addition, in Tables 18 to 20, the degree of suppression of the "animal odor" in the sample beverages of Test Examples 12, 44, 28, and 60 to 70 was evaluated using a sample beverage that did not contain hexanal or geraniol as a comparative control.

The degree of flavor harmony was also evaluated using the same method as in the sensory evaluation test in Test 2.

The results of the sensory evaluation test for the sample beverages of Test Examples 12 and 60 to 63 are shown in Table 18, the results of the sensory evaluation test for the sample beverages of Test Examples 44 and 64 to 67 are shown in Table 19, and the results of the sensory evaluation test for the sample beverages of Test Examples 28 and 68 to 70 are shown in Table 20.

The results in Tables 18 to 20 show that when the tannin concentration was 1 mg/100 mL, the gamey odor was not suppressed and the flavor was not harmonious, whereas when the tannin concentration was 10 mg/100 mL or more, the gamey odor was suppressed while the flavor was harmonious.

The present invention provides a packaged black tea beverage that contains milk protein and suppresses the gamey odor that is caused by milk protein in unsweetened black tea beverages, as well as a method for producing the same.

Claims (9)

A packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, said packaged black tea beverage further satisfying any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb; The packaged black tea beverage according to claim 1, which contains one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, purified milk protein, whey protein concentrate, purified whey protein, casein protein concentrate, and purified casein protein. The packaged black tea beverage according to claim 1 or 2, in which the ratio of the hexanal concentration (ppb) to the milk protein concentration (mass%) is 4.2 to 6670, or the ratio of the geraniol concentration (ppb) to the milk protein concentration (mass%) is 4.2 or more. A method for producing a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb; The method according to claim 4, wherein the packaged black tea beverage contains one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, purified milk protein, whey protein concentrate, purified whey protein, casein protein concentrate, and purified casein protein. The method according to claim 4 or 5, wherein the ratio of the hexanal concentration (ppb) to the milk protein concentration (mass%) in the packaged black tea beverage is 4.2 to 6670, or the ratio of the geraniol concentration (ppb) to the milk protein concentration (mass%) is 4.2 or more. A method for suppressing gamey odor in a packaged black tea beverage having a milk protein concentration of 0.3 mass% or more, a tannin concentration of 10 mg/100 mL or more, and a sugar concentration of less than 0.5 g/100 mL, characterized in that the packaged black tea beverage is prepared so as to further satisfy any one of the following conditions (a) to (c):
(a) the concentration of hexanal is 5 to 2000 ppb;
(b) the geraniol content is 5 ppb or more;
(c) the hexanal concentration is 5 to 2000 ppb and the geraniol concentration is 2 to 2000 ppb; The method according to claim 7, wherein the packaged black tea beverage contains one or more selected from the group consisting of milk, processed milk, concentrated milk, skim milk powder, whole milk powder, modified milk powder, milk protein concentrate, purified milk protein, whey protein concentrate, purified whey protein, casein protein concentrate, and purified casein protein. The method according to claim 7 or 8, wherein the ratio of the hexanal concentration (ppb) to the milk protein concentration (mass%) in the packaged black tea beverage is 4.2 to 6670, or the ratio of the geraniol concentration (ppb) to the milk protein concentration (mass%) is 4.2 or more.