JP7465081B2 - Packaged black tea beverage with reduced stuffy smell - Google Patents

Description

The present invention relates to a packaged black tea beverage in which the stuffy odor caused by heat sterilization or the like is suppressed, a method for producing the same, and a method for suppressing the stuffy odor of a packaged black tea beverage. More specifically, the present invention relates to a packaged black tea beverage in which the stuffy odor caused by heat sterilization or the like is suppressed, a method for producing the same, and a method for suppressing the stuffy odor of a packaged black tea beverage.

Tea beverages are a representative beverage that has long been popular as a luxury drink and health drink due to their unique aroma and refreshing taste created by their bitterness and astringency. Tea beverages are prepared from various types of tea, such as green tea, semi-fermented tea (oolong tea), and fermented tea (black tea), and in recent years have been distributed as packaged beverages in cans, plastic bottles, or paper cartons. Black tea beverages are one of the most popular tea beverages, due to their unique aroma and bitter and astringent taste, and are one of the most popular beverages from the perspective of preference or health consciousness, and black tea beverages prepared in various flavor variations are provided as packaged black tea beverages filled in cans, plastic bottles, etc. Some black tea beverages are available as straight types, in which the extracted taste of black tea leaves is enjoyed without adding fruit juice or milk.

Tea beverages are generally produced by extracting tea leaves with hot water, warm water, or room temperature water, removing tea leaf residue, and adjusting the extract to the desired concentration. In the production of packaged black tea beverages, heat sterilization is required to improve the shelf life of the packaged black tea beverage. However, such heat sterilization reduces the fresh green aroma in the black tea extract and increases off-flavors such as the smell of stale tea leaves (stuffy odor), spicy odor (spicy odor), and smoky odor (smoky odor). It is believed that these off-flavors are related to aroma components such as ketones, thiols, and phenols that increase with heat sterilization.

As a method for masking off-flavors (stuffy odors and unpleasant tastes) that occur over time and during sterilization in green tea beverages, Patent Document 1 discloses a method in which 0.5 to 3 volumes of ethanol are added to green tea extract concentrated to Brix 10 to 50°, and insoluble matter is removed, resulting in a tea beverage additive that is added to the green tea beverage at 0.0002 to 0.004 mass% of green tea extract solids. However, this method does not effectively suppress stuffy odors in black tea beverages.

Incidentally, (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol are fatty acid decomposition products. Heptenal and heptadienal are volatile organic compounds produced by the deterioration of fats and oils, and are known to cause unpleasant odors (Patent Documents 2 and 3). Octanol is also known to have an oily odor.

However, it was not previously known that adding one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol in a specific concentration range to a packaged black tea beverage can suppress the stuffy odor that occurs during heat sterilization or the like of the packaged black tea beverage.

Japanese Patent No. 4464099 JP 2014-002082 A JP 2019-518773 A

The objective of the present invention is to provide a packaged black tea beverage in which the stuffy odor caused by heat sterilization or the like is suppressed, a method for producing the same, and a method for suppressing the stuffy odor of a packaged black tea beverage.

As described above in the Background Art, there is a problem with packaged black tea beverages in that the fresh green aroma in the black tea extract is reduced and off-flavors such as the smell of stuffy tea leaves, spicy smell and smoky smell are increased by heat sterilization etc. In order to reduce these off-flavors to some extent, the applicant has investigated the following methods (p) to (r) in the production of packaged black tea beverages.
(p) The more highly fermented the black tea leaves used are, the stronger the musty odor will be, so use black tea leaves with a low degree of fermentation;
(q) The higher the extraction temperature of the black tea leaves, the stronger the musty odor will be, so the black tea leaves are extracted at a slightly lower temperature (about 65-80°C);
(r) increasing the flavoring addition rate to the black tea beverage to more effectively mask the stuffy odor;

However, the above method (p) has the problem that if low-fermented black tea leaves are used, the black tea beverage becomes more bitter, and the color of the black tea beverage is not strong enough and becomes a pale orange color. The supply of low-fermented black tea leaves to the market is small, making it difficult to secure a relatively large amount stably. The low-fermented black tea leaves are expensive, and the manufacturing cost of the packaged black tea beverage increases. The above method (q) has the problem that if the extraction temperature of the black tea leaves is somewhat low, the extraction efficiency of the black tea leaves decreases, and more black tea leaves are required, which increases the manufacturing cost of the packaged black tea beverage. The above method (r) has the problem that if the addition rate of the flavoring is increased, the packaged black tea beverage has an artificial aroma, and if the amount of flavoring used is increased, the manufacturing cost of the packaged black tea beverage increases.

Thus, none of the methods for dealing with the stuffy odor of packaged black tea beverages have been sufficient.
The inventors have found that by adding one or more fatty acid decomposition products selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol at a specific concentration to a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols, it is possible to suppress stuffy odors generated by heat sterilization treatments and the like and to maintain the flavor and aroma of a black tea beverage, leading to the completion of the present invention. The aforementioned fatty acid decomposition products are substances that can also cause off-flavors, and the finding that stuffy odors can be suppressed by such substances was surprising to those skilled in the art.

That is, the present invention provides
(1) A packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A packaged black tea beverage containing one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol at a concentration that satisfies at least one of the following (i) to (iii):
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb;
(2) A packaged black tea beverage according to the above (1), which further satisfies any one, two or three of the following (I) to (III):
(I) containing (E)-2-heptenal and (E,E)-2,4-heptadienal, and having a ratio of the (E,E)-2,4-heptadienal concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.011 to 15;
(II) containing (E)-2-heptenal and octanol, and having a ratio of the octanol concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.11 to 150;
(III) containing (E,E)-2,4-heptadienal and octanol, and having a ratio of the octanol concentration to the (E,E)-2,4-heptadienal concentration in a packaged black tea beverage of 0.67 to 150;
(3) A packaged black tea beverage according to the above (1) or (2), in which the pH of the beverage is 3.0 to 7.0;
(4) A packaged black tea beverage according to any one of (1) to (3) above, which is for sale heated;
(5) A packaged black tea beverage according to any one of (1) to (4) above, which is for long-term storage;
(6) In the production of a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A method for producing a packaged black tea beverage, comprising a step of incorporating one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol in a concentration that satisfies at least one of the following (i) to (iii):
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb;
(7) A method for producing a packaged black tea beverage according to the above (6), wherein the packaged black tea beverage further satisfies any one, two or three of the following (I) to (III):
(I) containing (E)-2-heptenal and (E,E)-2,4-heptadienal, and having a ratio of the (E,E)-2,4-heptadienal concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.011 to 15;
(II) containing (E)-2-heptenal and octanol, and having a ratio of the octanol concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.11 to 150;
(III) containing (E,E)-2,4-heptadienal and octanol, and having a ratio of the octanol concentration to the (E,E)-2,4-heptadienal concentration in a packaged black tea beverage of 0.67 to 150;
(8) In the production of a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A method for suppressing stuffy odor in a packaged black tea beverage, comprising a step of incorporating one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol in a concentration that satisfies at least one of the following (i) to (iii):
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb; and the like.

The present invention can provide a packaged black tea beverage in which the stuffy odor caused by heat sterilization or the like is suppressed, a method for producing the same, and a method for suppressing the stuffy odor of a packaged black tea beverage.

The present invention relates to
[1] A packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A packaged black tea beverage (hereinafter also referred to as "packaged black tea beverage of the present invention") containing one or more substances (hereinafter also referred to as "specific substances") selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol at a concentration (hereinafter also referred to as "specific concentration") that satisfies at least one (or two or three) of the following (i) to (iii);
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb; or
[2] In the production of a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A method for producing a packaged black tea beverage, comprising a step of incorporating one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol in a concentration that satisfies at least one (or two or three) of the above (i) to (iii) (hereinafter also referred to as the "production method of the present invention");
[3] In the production of a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A method for suppressing stuffy odor in a packaged black tea beverage, comprising the step of incorporating one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol in a concentration that satisfies at least one (or two or three) of the above-mentioned (i) to (iii) (hereinafter also referred to as the "suppression method of the present invention");
The present invention includes embodiments such as the above.

The packaged black tea beverage of the present invention is not particularly different from a conventional packaged black tea beverage in terms of the black tea raw materials and other optional ingredients used, and the manufacturing method and manufacturing conditions for the packaged black tea beverage, except that it contains one or more substances (specific substances) selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol at a concentration that satisfies at least one (or two or three) of the following (i) to (iii).
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb;

(Specific substances)
The specific substance in the present invention is one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol. (E)-2-heptenal is also called trans-2-heptenal, (E,E)-2,4-heptadienal is also called trans,trans-2,4-heptadienal, and octanol is also called 1-octanol or n-octanol.
The specific substances used in the present invention may be commercially available products.

The concentration of the specific substance in the packaged black tea beverage of the present invention may be such that one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol satisfy at least one (or two or three) of the following (i) to (iii). Note that (i) below is a combination of concentration ranges of the specific substance when at least (E)-2-heptenal is included, (ii) below is a combination of concentration ranges of the specific substance when at least (E,E)-2,4-heptadienal is included, and (iii) below is a combination of concentration ranges of the specific substance when at least octanol is included.

(i) (E)-2-heptenal is 5 to 450 ppb (preferably 5 to 300 ppb, more preferably 25 to 300 ppb, even more preferably 25 to 200 ppb, more preferably 50 to 200 ppb);
(E,E)-2,4-heptadienal is 75 ppb or less (preferably 5 to 75 ppb, 50 ppb or less, 5 to 50 ppb, 10 to 50 ppb, 25 to 50 ppb, 35 ppb or less, 10 to 35 ppb, 25 ppb or less, 5 to 25 ppb, 10 to 25 ppb, 10 ppb or less, 5 to 10 ppb, 5 ppb or less, 1 to 5 ppb, less than 1 ppb, or 0 ppb), and
octanol is 750 ppb or less (preferably 50-750 ppb, 500 ppb or less, 50-500 ppb, 75-500 ppb, 100-500 ppb, 300 ppb or less, 50-300 ppb, 75-300 ppb, 100-300 ppb, 200 ppb or less, 50-200 ppb, 75-200 ppb, 100-200 ppb, 100 ppb or less, 50-100 ppb, 75-100 ppb, 75 ppb or less, 50-75 ppb, 50 ppb or less, 10-50 ppb, less than 10 ppb, or 0 ppb);

(ii) (E)-2-heptenal is 450 ppb or less (preferably 5 to 450 ppb, 300 ppb or less, 5 to 300 ppb, 25 to 300 ppb, 100 to 300 ppb, 200 ppb or less, 25 to 200 ppb, 50 to 200 ppb, 100 to 200 ppb, 100 ppb or less, 5 to 100 ppb, 25 to 100 ppb, 50 to 100 ppb, 25 ppb or less, 1 to 25 ppb, 5 to 25 ppb, 5 ppb or less, 1 to 5 ppb, less than 1 ppb, or 0 ppb);
(E,E)-2,4-heptadienal is 5 to 75 ppb (preferably 5 to 50 ppb, more preferably 10 to 50 ppb, even more preferably 10 to 35 ppb or 25 to 50 ppb), and
octanol is 750 ppb or less (preferably 50-750 ppb, 500 ppb or less, 50-500 ppb, 75-500 ppb, 100-500 ppb, 300 ppb or less, 50-300 ppb, 75-300 ppb, 100-300 ppb, 200 ppb or less, 50-200 ppb, 75-200 ppb, 100-200 ppb, 100 ppb or less, 50-100 ppb, 75-100 ppb, 75 ppb or less, 50-75 ppb, 50 ppb or less, 10-50 ppb, less than 10 ppb, or 0 ppb);

(iii) (E)-2-heptenal is 450 ppb or less (preferably 50 to 750 ppb, 500 ppb or less, 50 to 500 ppb, 75 to 500 ppb, 100 to 500 ppb, 300 ppb or less, 50 to 300 ppb, 75 to 300 ppb, 100 to 300 ppb, 200 ppb or less, 50 to 200 ppb, 75 to 200 ppb, 100 to 200 ppb, 100 ppb or less, 50 to 100 ppb, 75 to 100 ppb, 75 ppb or less, 50 to 75 ppb, 50 ppb or less, 10 to 50 ppb, less than 10 ppb, or 0 ppb);
(E,E)-2,4-heptadienal is 75 ppb or less (preferably 5 to 75 ppb, 50 ppb or less, 5 to 50 ppb, 10 to 50 ppb, 25 to 50 ppb, 35 ppb or less, 10 to 35 ppb, 25 ppb or less, 5 to 25 ppb, 10 to 25 ppb, 10 ppb or less, 5 to 10 ppb, 5 ppb or less, 1 to 5 ppb, less than 1 ppb, or 0 ppb), and octanol is 50 to 750 ppb (preferably 50 to 500 ppb, more preferably 50 to 300 ppb, even more preferably 50 to 200 ppb, 50 to 100 ppb, 75 to 200 ppb, or 75 to 100 ppb);

The concentration of a specific substance in the packaged black tea beverage of the present invention can be measured by gas chromatography-mass spectrometry (GC-MS). Measurement conditions for such GC-MS include those described in "4. Equipment and analytical conditions" at the bottom left of page 947 of Yang et. al., Nippon Shokuhin Kogyo Gakkaishi Vol.37, No.12, 946-952 (1990).

When two or three types of specific substances are contained in the packaged black tea beverage of the present invention, in addition to the two or three types of specific substances being at concentrations that satisfy at least any two or three of (i) to (iii), it is preferable from the viewpoint of more fully suppressing stuffy odors and more fully suppressing spicy odors and smoky odors during long-term storage that the concentration ratio of the two specific substances satisfy any one, two or three of (I) to (III) below. Note that (I) below is the concentration ratio when the packaged black tea beverage of the present invention contains (E)-2-heptenal and (E,E)-2,4-heptadienal, (II) below is the concentration ratio when (E)-2-heptenal and octanol are contained, and (III) below is the concentration ratio when (E,E)-2,4-heptadienal and octanol are contained.
(I) containing (E)-2-heptenal and (E,E)-2,4-heptadienal, and the ratio of the concentration of (E,E)-2,4-heptadienal to the concentration of (E)-2-heptenal in a packaged black tea beverage is preferably 0.011 to 15, more preferably 0.017 to 10, even more preferably 0.05 to 2, and more preferably 0.05 to 0.5;
(II) containing (E)-2-heptenal and octanol, and the ratio of the octanol concentration to the (E)-2-heptenal concentration in the packaged black tea beverage is preferably 0.11 to 150, more preferably 0.17 to 100, even more preferably 0.25 to 20, more preferably 0.5 to 10, or 0.5 to 5;
(III) containing (E,E)-2,4-heptadienal and octanol, and having a ratio of the octanol concentration to the (E,E)-2,4-heptadienal concentration in a packaged black tea beverage of 0.67 to 150, more preferably 1 to 100, even more preferably 2 to 50, and more preferably 2 to 20;

The "concentration of a specific substance" or the "ratio of concentrations of two specific substances" in a packaged black tea beverage can be adjusted by adjusting the amount of the specific substance contained (or added) to the packaged black tea beverage.
In addition, containing a specific substance at a specific concentration in a packaged black tea beverage includes a method of containing (preferably adding) a specific substance to a black tea beverage at any stage in the production process of the packaged black tea beverage so that the concentration of the specific substance in the packaged black tea beverage is a specific concentration, and this method also includes a method in which the amount of the specific substance added results in a specific concentration when converted into the liquid volume of the packaged black tea beverage.

(Tea polyphenol concentration)
The tea polyphenol concentration in the present invention means the value of the total polyphenol concentration in the packaged black tea beverage of the present invention measured by ferrous tartrate absorptiometry (preferably the official method (ferrous tartrate method) described in "Commentary on the Japanese Food Standard Composition Analysis Manual, 5th Edition," edited by Japan Food Research Center, Chuohoki, July 2001, p. 252).

The tea polyphenol concentration in the packaged black tea beverage of the present invention is 100 to 1000 ppm, and from the viewpoint of greater significance in suppressing stuffy odor, the tea polyphenol concentration is preferably a certain level or higher, and from the viewpoint of more fully suppressing stuffy odor, it is preferably a certain level or lower. Specifically, the preferred tea polyphenol concentration in the packaged black tea beverage of the present invention is preferably 100 to 800 ppm, more preferably 150 to 700 ppm, and even more preferably 200 to 600 ppm.

(Tea drinks)
Black tea beverages are defined by the Ministry of Agriculture, Forestry and Fisheries' quality labeling guidelines for black tea beverages as "a beverage made by extracting or infusing tea plant buds and leaves that have been fermented with enzymes in-house (including those with added flavorings) (including those made by diluting concentrated or powdered versions of these), or those to which sugar, dairy products, fruit juice, flavorings, etc. have been added, sealed in a container and then served directly."

The black tea extract raw material used in the packaged black tea beverage of the present invention is not particularly limited, and black tea extract raw materials conventionally used in the manufacture of black tea beverages, such as extracts from black tea leaves and processed products thereof (concentrated liquid extract, powder extract, etc.), can be used. In addition, they can be freely selected according to the flavor design. The type of black tea leaves used as raw materials for the black tea extract and black tea extract, adjustment of extraction conditions, and use of multiple tea leaves in combination are not particularly limited, and can be freely selected according to the flavor design. In addition, since stuffy odor is likely to occur, a method using black tea leaves with a relatively high fermentation degree and a method extracting black tea leaves at a temperature above 80°C are preferred in that the significance of the present invention is enhanced. The content of the black tea extract raw material in the packaged black tea beverage of the present invention is not particularly limited, but a content that causes the total polyphenol concentration in the black tea beverage to be in the above-mentioned range is preferred.

As the degree of fermentation of tea increases from green tea to semi-fermented tea (oolong tea) to fermented tea (black tea), the polymerization of monomeric catechins progresses, and the formation of polymerized catechins such as theaflavins advances. The packaged black tea beverage of the present invention can be characterized as having a ratio of non-gallated catechins/gallated catechins of 1.1 or less. More preferably, the ratio of non-gallated catechins/gallated catechins is 1 or less, and even more preferably, the ratio of non-gallated catechins/gallated catechins is 0.9 or less.

The packaged black tea beverage of the present invention can be characterized as having a ratio of non-epi-catechins/epi-catechins of 1.5 or less. More preferably, the ratio of non-epi-catechins/epi-catechins is 1.2 or less, and even more preferably, the ratio of non-epi-catechins/epi-catechins is 1 or less.

Tea leaves contain tannins as tea polyphenols, which are the substances that cause tea's astringency. One type of tannin is catechin, and non-polymerized catechins are divided into the following eight main types: (1) catechin (C); (2) epicatechin (EC); (3) catechin gallate (Cg); (4) epicatechin gallate (ECg); (5) gallocatechin (GC); (6) gallocatechin gallate (GCCg); (7) epigallocatechin (EGC); (8) epigallocatechin gallate (EGCg). Among the non-polymerized catechins, those with "gallate" at the end are called "gallate type", and those with "epi" at the beginning are called "epi-form".

(Optional ingredients)
The packaged black tea beverage of the present invention may contain optional ingredients (e.g., sweeteners, milk components, antioxidants, nutrients, flavorings, etc.) that are commonly used in packaged black tea beverages, provided that the effects of the present invention are not impaired. However, it is preferable that the beverage does not contain either one or both of sweeteners and milk components, as this will result in a stronger stuffy smell and enhance the significance of the present invention.

(pH)
In the production of the packaged black tea beverage of the present invention, it is not necessary to adjust the pH of the black tea beverage, but from the viewpoint of maintaining the flavor of the packaged black tea beverage for a longer period of time, the pH can be adjusted to, for example, 3 to 7, preferably 4 to 7, and more preferably 5 to 7. The pH can be adjusted by adding various alkaline salts as pH adjusters according to the flavor design of the packaged black tea beverage. As the pH adjuster, it is preferable to use one or more alkaline agents selected from the group including sodium hydrogen carbonate, sodium carbonate, sodium hydroxide, and other alkaline agents containing sodium salts, and it is more preferable to use a sodium salt such as sodium hydrogen carbonate.

(container)
Examples of containers for the packaged black tea beverage of the present invention include resin bottle containers such as PET bottles, polypropylene bottles, and polyvinyl chloride bottles; glass containers; and can containers.

(Sterilization)
In the case of metal cans, which can be sterilized by heating after filling, sterilization in the manufacturing process of the packaged black tea beverage can be carried out under the sterilization conditions stipulated in the Food Sanitation Act, etc. For containers which cannot be sterilized by retort, such as PET bottles and paper containers, 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 or the like, before filling, and then cooled to a certain temperature and filled into the sterilized container.

(Sales temperature)
The selling temperature of the packaged black tea beverage of the present invention at a retail store or vending machine is not particularly limited, but since the spicy odor and smoky odor are more likely to be produced and the significance of the present invention is enhanced, it is preferable that the packaged black tea beverage of the present invention is a packaged black tea beverage for sale heated. Examples of such heated sales include selling the packaged black tea beverage by heating it to 50 to 70°C.

(Long-term storage)
The packaged black tea beverage of the present invention does not have to be for long-term storage, but is preferably for long-term storage in order to enhance the significance of the present invention. A packaged black tea beverage for long-term storage means a packaged black tea beverage with a best-before date of 180 days or more, and preferably includes a packaged black tea beverage with an upper limit of the best-before date in the range of 450 to 540 days.

(Suppression of stuffy odor)
In the present invention, "stuffy smell" is not particularly limited as long as it is the smell of steamed tea leaves, but means, for example, a smell like steamed sweet potato, a smell like boiled chestnuts, a smell like mushrooms, or a mixture of two or three of these smells, etc. In the present invention, a packaged black tea beverage with "suppressed stuffy smell" means a packaged black tea beverage in which the stuffy smell is suppressed (reduced) compared with a packaged black tea beverage (hereinafter also referred to as a "control beverage") produced by the same method using the same types of raw materials to give the same final concentrations, except that it does not contain (or does not add) any of the three specific substances of the present invention.

A trained panel can easily and clearly determine how the stuffy odor of a packaged black tea beverage is compared with that of a control beverage (e.g., whether it is suppressed) or the degree of suppression of the stuffy odor. The evaluation criteria and the method of summarizing the evaluations among the panelists can be general methods. The number of panelists evaluating the degree of suppression of the stuffy odor of a packaged black tea beverage may be one, but from the viewpoint of obtaining a more objective evaluation, the lower limit of the number of panelists can be, for example, two or more, preferably three or more, and from the viewpoint of conducting the evaluation test more easily, the upper limit of the number of panelists can be, for example, 20 or less, 10 or less. When there are two or more panelists, the evaluation of the degree of suppression of the stuffy odor of the packaged black tea beverage may be the average of the evaluations of all the panelists regarding the degree of suppression of the stuffy odor of the packaged black tea beverage. When an integer evaluation score is assigned to each evaluation criterion, the average of the evaluation scores of all the panelists may be used as the evaluation of the degree of suppression of the stuffy odor of the packaged black tea beverage. As described above, when the average value of the evaluation points is adopted, the value obtained by rounding the average value to the first or second decimal place (preferably to the second decimal place) may be adopted. When there are two or more panelists, in order to reduce the variation in the evaluations of each panelist, it is preferable to standardize the evaluation criteria so that the evaluation criteria of each panelist are as consistent as possible before the actual sensory evaluation test is conducted. Such standardization can be performed by having each panelist evaluate the degree of suppression of stuffy odor for multiple types of packaged black tea beverages with known degrees of suppression of stuffy odor, and then comparing the evaluation scores to confirm that there is no significant deviation in the evaluation criteria of each panelist. It is also preferable that such prior standardization of the evaluation criteria ensures that the standard deviation of the evaluations of the degree of suppression of stuffy odor by each panelist when the evaluation scores are 1, 2, 3, 4, and 5 is within 0.5.

The state of the stuffy odor in a certain packaged black tea beverage compared to a control beverage (e.g., whether it is suppressed) or the degree of suppression of the stuffy odor can be suitably determined, for example, by a method similar to the method using the evaluation criteria (Table 3) described in Test 2 of the Example described below, preferably by the same method using the evaluation criteria (Table 3) described in Test 2 of the Example described below. More specifically, packaged black tea beverages in which the stuffy odor is suppressed even slightly compared to the degree of stuffy odor in the control beverage (for example, packaged black tea beverages with an average panelist rating of 1.5 points or more (preferably 2 points or more) according to the rating criteria in Table 3) are included in packaged black tea beverages in which the stuffy odor is suppressed.

(Suppression of spicy and smoky odors)
In the present invention, the spicy odor is not particularly limited, but means, for example, a clove-like odor, a nutmeg-like odor, or a mixture of these odors. The smoky odor is not particularly limited, but means, for example, a smoked odor, a burnt odor, or a mixture of these odors. Furthermore, a packaged black tea beverage in which the "spicy odor and smoky odor are suppressed" means a packaged black tea beverage in which the spicy odor and smoky odor are suppressed (reduced) compared to a control beverage when a certain packaged black tea beverage and its control beverage are stored, for example, under conditions of 50 to 70°C for 3 weeks or more (preferably 3 to 6 weeks).

A trained panel can easily and clearly determine how the spicy and smoky odors of a packaged black tea beverage are compared with a control beverage (e.g., whether they are suppressed) or the degree of suppression. The evaluation criteria and the method of summarizing the evaluations among the panelists can be general methods. The number of panelists evaluating the degree of suppression of the spicy and smoky odors of the packaged black tea beverage may be one, but from the viewpoint of obtaining a more objective evaluation, the lower limit of the number of panelists can be, for example, two or more, preferably three or more, and from the viewpoint of conducting the evaluation test more simply, the upper limit of the number of panelists can be, for example, 20 or less, 10 or less. When the panelists are two or more, the evaluation of the degree of suppression of the spicy and smoky odors of the packaged black tea beverage may be the average of the evaluations of all the panelists regarding the degree of suppression of the spicy and smoky odors of the packaged black tea beverage. When an integer evaluation score is assigned to each evaluation criterion, the average of the evaluation scores of all panelists may be used as the evaluation of the degree of suppression of the spicy odor and smoky odor of the packaged black tea beverage. As described above, when the average of the evaluation scores is used, the average may be rounded off to the first or second decimal place (preferably to the second decimal place). In addition, when there are two or more panelists, in order to reduce the variation in the evaluations of each panelist, it is preferable to carry out a common evaluation criterion so that the evaluation criteria of each panelist are as consistent as possible before carrying out the actual sensory evaluation test. Such a common evaluation criterion may be carried out by having each panelist evaluate the degree of suppression of the spicy odor and smoky odor of multiple types of packaged black tea beverages with known degrees of suppression of the spicy odor and smoky odor, and then comparing the evaluation scores to confirm that there is no significant deviation in the evaluation criteria of each panelist. In addition, it is preferable to standardize the evaluation criteria in advance so that the standard deviation of each panelist's evaluation of the degree of suppression of spicy and smoky odors when the evaluation points are 1, 2, 3, 4, and 5 is within 0.5.

The spicy and smoky odors of a certain packaged black tea beverage compared to a control beverage (e.g., whether they are suppressed) or the degree of suppression can be determined, for example, by a method similar to the method using the evaluation criteria (Table 10) described in Test 4 of the Example described below, preferably by the same method using the evaluation criteria (Table 10) described in Test 4 of the Example described below. More specifically, packaged black tea beverages in which the spicy and smoky odors are suppressed even slightly compared to the degree of the spicy and smoky odors of the control beverage (e.g., packaged black tea beverages with an average panelist rating of 1.5 points or more (preferably 2 points or more) according to the rating criteria in Table 10) are included in packaged black tea beverages in which the spicy and smoky odors are suppressed.

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

[Test 1] The effect of containing various fatty acid decomposition products in packaged black tea beverages on the flavor of the packaged black tea beverages As mentioned above, fatty acid decomposition products are considered to be substances that cause off-flavors. However, the present inventors thought that even such fatty acid decomposition products might have a favorable effect on the flavor of packaged black tea beverages depending on their type and concentration, and investigated the effects of the following 10 types of fatty acid decomposition products on the flavor of packaged black tea beverages as a preliminary experiment.

1. Preparation of Black Tea Extract
100 g of Kenya-Indonesian blend black tea leaves were placed in 3000 g of ion-exchanged water at 90° C. and extracted for 6 minutes. The resulting extract containing the tea leaves was subjected to solid-liquid separation (filtration) and then centrifuged at room temperature to obtain the supernatant as black tea extract (black tea extract).

(2. Preparation of Packaged Black Tea Beverage)
A mixture was prepared by adding appropriate amounts of L-ascorbic acid and sodium hydrogen carbonate to the black tea extract extracted from black tea leaves using the method described above in (1. Preparation of black tea extract). This mixture was supplemented with 50 ppb of each of the 10 types of fatty acid decomposition products shown in Table 2 below, to prepare 10 types of black tea beverages. Each black tea beverage was sterilized by the UHT method (at least 120°C for 4 minutes) and then filled into a PET bottle, obtaining the packaged black tea beverages of Test Examples 1 to 10.

(3. Sensory Evaluation Test)
For each of the resulting packaged black tea beverages of Test Examples 1 to 10, a panel of eight experts conducted a sensory evaluation test to determine whether the off-flavor was within an acceptable range, using the evaluation criteria in Table 1 below. If the off-flavor was beyond the acceptable range, the expert panel conducted a sensory evaluation in which the aroma of the off-flavor was freely described. The "off-flavor" was evaluated based on an aroma that had changed from the original gorgeous aroma of black tea.

The results of the sensory evaluation test for the packaged black tea beverages of Test Examples 1 to 10 are shown in Table 2.

The results in Table 2 show that of the 10 fatty acid decomposition products, three types, (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol, have off-flavors within the acceptable range at a concentration of 50 ppb. Therefore, we decided to conduct a more detailed study of these three fatty acid decomposition products (hereinafter simply referred to as "substances") in Test 2 below.

[Test 2] Effect of the inclusion of three substances in a packaged black tea beverage on stuffy odor, etc. of the packaged black tea beverage It is known that when a packaged black tea beverage is heat sterilized, the green aroma decreases and the off-flavor like stuffy tea leaves (the so-called "stuffy odor") and spicy off-flavor increase. Therefore, the following method was used to examine what effect the inclusion of any one of the three substances, (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol, in a packaged black tea beverage has on stuffy odor, etc., caused by heat sterilization of the packaged black tea beverage.

1. Preparation of Black Tea Extract
100 g of Kenya-Indonesia blend black tea leaves were placed in 3000 g of 90° C. ion-exchanged water and extracted for 6 minutes. The resulting extract containing the tea leaves was subjected to solid-liquid separation (filtration) and then centrifuged at room temperature to obtain the supernatant as black tea extract (black tea extract). The tea polyphenol concentration of this black tea extract was measured using ferric tartrate absorptiometry and found to be 400 ppm.

(2. Preparation of Packaged Black Tea Beverage)
A mixture was prepared by adding appropriate amounts of L-ascorbic acid and sodium hydrogen carbonate to the black tea extract extracted from black tea leaves by the method described above in (1. Preparation of black tea extract). Any one of three types of substances was added to this mixture at the concentration shown in Table 6 below, to prepare each black tea beverage. Each black tea beverage was sterilized by the UHT method (at 120°C for 4 minutes or more), and then filled into a PET bottle to obtain each packaged black tea beverage (the packaged black tea beverages of Examples 1 to 10 and Comparative Examples 2 to 7). A packaged black tea beverage of Comparative Example 1 was also prepared without adding any of the three types of substances.

(3. Sensory Evaluation Test)
A sensory evaluation test was carried out by a panel of eight experts on the degree of suppression of the stuffy odor of the packaged black tea beverages obtained in Examples 1 to 10 and Comparative Examples 1 to 7, and the degree of reduction in off-flavors other than the stuffy odor. The degree of suppression of the stuffy odor of the packaged black tea beverages of Comparative Example 1, which did not contain any of the three substances, was used as the standard, and the degree of suppression of the stuffy odor of the packaged black tea beverages of the Examples, which contained the substances, was evaluated according to the criteria in Table 3 below. The degree of reduction in off-flavors other than the stuffy odor was evaluated according to the criteria in Table 4 below. Note that off-flavors derived from the added fatty acid decomposition products (one or two of the above three substances) were evaluated as off-flavors other than the stuffy odor. In order to reduce the variation in the evaluations of each panel, each panel evaluated the degree of suppression of stuffy odor for several types of packaged black tea beverages with known degrees of suppression of stuffy odor, and then the evaluation scores were compared to confirm that there was no significant deviation in the evaluation criteria of each panel, and that the standard deviation of the evaluation scores of each panel was within 0.5. A similar confirmation process was also carried out by eight panels on the degree of suppression of off-flavors other than stuffy odor.

For both the degree of suppression of stuffy odor and the degree of reduction of off-flavors other than stuffy odor, the average score of the eight expert panel members was calculated for each packaged black tea beverage, and this average score was used as the evaluation of that packaged black tea beverage.

Additionally, each packaged black tea beverage was given an overall rating (good or bad) based on the criteria in Table 5 below.

The evaluation results for each packaged black tea beverage of Examples 1 to 10 and Comparative Examples 1 to 7 are shown in Table 6 below.

The results in Table 6 show that when any of the three substances ((E)-2-heptenal, (E,E)-2,4-heptadienal, octanol) is added to a packaged black tea beverage at a specified concentration, it is possible to suppress the stuffy odor while keeping off-flavors other than the stuffy odor low. From the perspective of suppressing the stuffy odor while keeping off-flavors other than the stuffy odor low in a packaged black tea beverage, the concentration of (E)-2-heptenal is preferably 5 to 450 ppb, preferably 5 to 300 ppb, more preferably 25 to 300 ppb, even more preferably 25 to 200 ppb, more preferably 50 to 200 ppb, and the concentration of (E,E)-2,4-heptadienal is preferably 5 to 75 ppb. , preferably 5 to 50 ppb, more preferably 10 to 50 ppb, even more preferably 10 to 35 ppb or 25 to 50 ppb, and the octanol concentration is preferably 50 to 750 ppb, preferably 50 to 500 ppb, more preferably 50 to 300 ppb, even more preferably 50 to 200 ppb, 50 to 100 ppb, 75 to 200 ppb, or 75 to 100 ppb.

[Test 3] Effect of using two substances in combination on stuffy odor, etc. in packaged black tea beverages A method similar to that used in Test 2 above was used to investigate what effect the inclusion of two of the three substances, (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol, in a packaged black tea beverage would have on stuffy odor, etc. caused by heat sterilization of the packaged black tea beverage.

Specifically, except that two of the three substances were used in combination, the packaged black tea beverages of Examples 11 to 16 were prepared in the same manner as in Test 2 above (see Table 7 for the types and concentrations of substances), and a sensory evaluation test was carried out on these packaged black tea beverages in the same manner as in Test 2 above. The results are shown in Table 7 below.

In addition, "B/A C/A" in Table 7 represents B/A (the ratio of B to A) or C/A (the ratio of C to A) when the concentration of (E)-2-heptenal is "A", the concentration of (E,E)-2,4-heptadienal is "B", and the concentration of octanol is "C".

As can be seen from the results in Table 7, it was shown that when the substances (E)-2-heptenal and (E,E)-2,4-heptadienal were used in combination, or when (E)-2-heptenal and octanol were used in combination, it was possible to suppress the stuffy odor while keeping off-flavors other than the stuffy odor low in packaged black tea beverages. Note that since (E,E)-2,4-heptadienal and octanol were each effective alone (Table 6), it is highly likely that the stuffy odor can be suppressed while keeping off-flavors other than the stuffy odor low in packaged black tea beverages, just as when (E)-2-heptenal and (E,E)-2,4-heptadienal were used in combination (Table 7) and when (E)-2-heptenal and octanol were used in combination (Table 7).

From the results in Table 7, from the viewpoint of suppressing stuffy odor while keeping off-flavors other than stuffy odor low in a packaged black tea beverage, the ratio of the (E,E)-2,4-heptadienal concentration to the (E)-2-heptenal concentration in the packaged black tea beverage (i.e., "B/A") is preferably 0.05 to 0.5, more preferably 0.05 to 0.35, and even more preferably 0.05 to 0.25.
However, when the findings from Table 6, which shows the results when each of the three substances was used alone ("The concentration of (E)-2-heptenal is 5 to 450 ppb, preferably 5 to 300 ppb, more preferably 25 to 300 ppb, even more preferably 25 to 200 ppb, and more preferably 50 to 200 ppb" and "The concentration of (E,E)-2,4-heptadienal is 5 to 75 ppb, preferably 5 to 50 ppb, more preferably 10 to 50 ppb, and even more preferably 10 to 35 ppb or 25 to 50 ppb") are taken into consideration together with the results of Table 7,
When (E)-2-heptenal is 450 ppb and (E,E)-2,4-heptadienal is 5 ppb ("B / A" ≒ 0.011),
When (E)-2-heptenal is 300 ppb and (E,E)-2,4-heptadienal is 5 ppb ("B / A" ≒ 0.017),
When (E)-2-heptenal is 5 ppb and (E,E)-2,4-heptadienal is 50 ppb ("B / A" ≒ 10),
Even when (E)-2-heptenal is 5 ppb and (E,E)-2,4-heptadienal is 75 ppb ("B/A" ≈ 15), it is considered highly likely that the stuffy odor can be suppressed while maintaining low levels of off-flavors other than the stuffy odor in a packaged black tea beverage. Therefore, from the results in Tables 6 and 7, from the perspective of suppressing the stuffy odor while maintaining low levels of off-flavors other than the stuffy odor in a packaged black tea beverage, examples of "B/A" include 0.011 to 15, 0.011 to 10, 0.017 to 15, 0.017 to 10, 0.05 to 2, and 0.05 to 0.5.

From the results in Table 7, from the viewpoint of suppressing stuffy odor while keeping off-flavors other than stuffy odor low in a packaged black tea beverage, the ratio of octanol concentration to (E)-2-heptenal concentration in the packaged black tea beverage (i.e., "C/A") is preferably 0.5 to 5, more preferably 0.5 to 3.5, and even more preferably 0.5 to 2.5.
However, when the findings from Table 6, which shows the results when each of the three substances was used alone ("(E)-2-heptenal concentration: 5 to 450 ppb, preferably 5 to 300 ppb, more preferably 25 to 300 ppb, even more preferably 25 to 200 ppb, more preferably 50 to 200 ppb" and "octanol concentration: 50 to 750 ppb, preferably 50 to 500 ppb, more preferably 50 to 300 ppb, even more preferably 50 to 200 ppb, 50 to 100 ppb, 75 to 200 ppb, or 75 to 100 ppb") and the results in Table 7 are taken into consideration,
(E)-2-heptenal is 450 ppb and octanol is 50 ppb ("C / A" ≒ 0.11),
(E)-2-heptenal is 300 ppb and octanol is 50 ppb ("C / A" ≒ 0.17),
(E)-2-heptenal is 5 ppb and octanol is 500 ppb ("C / A" ≒ 100),
Even when (E)-2-heptenal is 5 ppb and octanol is 750 ppb ("C/A" ≈ 150), it is considered highly likely that the stuffy odor can be suppressed while maintaining low off-flavors other than the stuffy odor in a packaged black tea beverage. Therefore, from the results in Tables 6 and 7, from the perspective of suppressing the stuffy odor while maintaining low off-flavors other than the stuffy odor in a packaged black tea beverage, "C/A" can also be 0.11 to 150, 0.11 to 100, 0.17 to 150, 0.17 to 100, 0.25 to 20, and more preferably 0.5 to 10, 0.5 to 5, etc.

In addition, the results when (E,E)-2,4-heptadienal and octanol were used in combination are not shown in FIG. 7, but considering the findings obtained from Table 6, which shows the results when the three substances were used alone ("(E,E)-2,4-heptadienal concentration: 5 to 75 ppb, preferably 5 to 50 ppb, more preferably 10 to 50 ppb, even more preferably 10 to 35 ppb or 25 to 50 ppb" and "octanol concentration: 50 to 750 ppb, preferably 50 to 500 ppb, more preferably 50 to 300 ppb, even more preferably 50 to 200 ppb, 50 to 100 ppb, 75 to 200 ppb or 75 to 100 ppb"),
When (E,E)-2,4-heptadienal is 75 ppb and octanol is 50 ppb ("C/B" ≒ 0.67),
When (E,E)-2,4-heptadienal is 50 ppb and octanol is 50 ppb ("C/B" ≒ 1),
When (E,E)-2,4-heptadienal is 5 ppb and octanol is 500 ppb ("C/B" ≒ 100),
Even when (E,E)-2,4-heptadienal is 5 ppb and octanol is 750 ppb ("C/B" ≒ 150), it is highly likely that the stuffy odor can be suppressed while off-flavors other than the stuffy odor are kept low in a packaged black tea beverage.
Therefore, the ratio of octanol to the (E,E)-2,4-heptadienal concentration in the packaged black tea beverage (i.e., "C/B") is:
Therefore, from the results in Table 6 and the like, from the perspective of suppressing the stuffy odor while keeping off-flavors other than the stuffy odor low in a packaged black tea beverage, "C/A" can also be set to 0.67 to 150, 0.67 to 100, 1 to 150, 1 to 100, 2 to 50, 2 to 20, and the like.

[Test 4] Effect of tea polyphenol concentration on stuffy odor, etc. of packaged black tea beverage The effect of the tea polyphenol concentration in a packaged black tea beverage on stuffy odor, etc. caused by heat sterilization of the packaged black tea beverage was investigated using the following method.

1. Preparation of Black Tea Extract
Five types of black tea extracts having tea polyphenol concentrations of 100 ppm, 200 ppm, 400 ppm, 600 ppm, and 800 ppm were prepared by the following method.
A predetermined amount of Kenya-Indonesia blend black tea leaves was placed in a predetermined amount of ion-exchanged water at 90°C and extracted for 6 minutes. To prepare black tea extracts with tea polyphenol concentrations of 100 ppm, 200 ppm, 400 ppm, 600 ppm, and 800 ppm, 0.15 wt%, 0.3 wt%, 0.6 wt%, 0.9 wt%, and 1.2 wt% of black tea leaves were used, respectively, relative to the total weight of the black tea leaves and ion-exchanged water. The obtained extracts containing tea leaves were subjected to solid-liquid separation (filtration) and then centrifuged at room temperature to obtain the supernatant as black tea extract (black tea extract). The tea polyphenol concentrations of these five types of black tea extracts were measured using ferric tartrate absorptiometry and confirmed to be 100 ppm, 200 ppm, 400 ppm, 600 ppm, and 800 ppm, respectively.

(2. Preparation of Packaged Black Tea Beverage)
Appropriate amounts of L-ascorbic acid and sodium bicarbonate were added to each of the black tea extracts extracted from black tea leaves by the method of (1. Preparation of black tea extract) above to prepare mixed solutions with predetermined tea polyphenol concentrations. (E)-2-heptenal and octanol were added to these mixed solutions at the concentrations shown in Table 9 below to prepare each black tea beverage. Each black tea beverage was sterilized by the UHT method (at least 120°C for 4 minutes) and then filled into a PET bottle to obtain each packaged black tea beverage (the packaged black tea beverages of Examples 17 to 21). In addition, the packaged black tea beverages of Comparative Examples 8 to 12 were prepared without adding either of the above two types of substances.

(3. Sensory Evaluation Test)
A sensory evaluation test was carried out by eight expert panels on the degree of suppression of stuffy odor of each of the packaged black tea beverages of Examples 17 to 21 and Comparative Examples 8 to 12 obtained. The degree of suppression of stuffy odor of the packaged black tea beverage of each Example was evaluated according to the criteria (5-level) in Table 8 below, using the stuffy odor of a packaged black tea beverage of a Comparative Example, which has the same tea polyphenol concentration as the packaged black tea beverage of each Example and does not contain either (E)-2-heptenal or octanol, as the standard. In order to reduce the variation in the evaluation of each panel, each panel evaluated the degree of suppression of stuffy odor of multiple types of packaged black tea beverages with known degrees of suppression of stuffy odor, and then the evaluation scores were compared to confirm that there was no significant deviation in the evaluation criteria of each panel, and it was also confirmed that the standard deviation of the evaluation scores of each panel was within 0.5.

The degree of suppression of stuffy odor for each packaged black tea beverage was evaluated by calculating the average score of the eight expert panel members, and this average score was used as the evaluation of the degree of suppression of stuffy odor for that packaged black tea beverage. In addition, the overall evaluation was determined as follows: an average score of 2.5 points or more was designated as "Good", an average score of 1.5 points or more but less than 2.5 points was designated as "Good", and an average score of less than 1.5 points was designated as "Poor".

The evaluation results for each packaged black tea beverage of Examples 17 to 21 and Comparative Examples 8 to 12 are shown in Table 9 below.

As can be seen from the results in Table 9, it was shown that in packaged black tea beverages, regardless of whether the tea polyphenol concentration was 100 to 800 ppm, the stuffy odor could be suppressed while maintaining low levels of off-flavors other than the stuffy odor, but a more excellent effect was obtained when the concentration was 200 to 600 ppm. The stronger the black tea-derived components, the stronger the stuffy odor generated. The reason why the average score for the degree of suppression of stuffy odor when the tea polyphenol concentration was 100 ppm (Example 17) was lower than that when it was, for example, 200 ppm (Example 18) is thought to be because the stuffy odor generated was not very strong to begin with, making it difficult to distinguish between the comparative example and the example. On the other hand, when the tea polyphenol concentration was 800 ppm, the stuffy odor generated was quite strong, and the degree of stuffy odor that could be suppressed by adding a substance was lower than when it was, for example, 200 ppm.

[Test 4] Confirmation of the effect of suppressing spicy odor and smoky odor in packaged black tea beverage heated for a long period As described in the Background Art, a packaged black tea beverage that has been heat sterilized generates a spicy odor and a smoky odor. When such a packaged black tea beverage is heated for a long period in a hot showcase when sold as a hot drink in a retail store, the spicy odor and smoky odor increase. Therefore, whether or not the specific substance of the present invention exerts an effect of suppressing the spicy odor and smoky odor in a packaged black tea beverage heated for a long period was confirmed by the following method.

1. Preparation of Black Tea Extract
100 g of Kenya-Indonesia blend black tea leaves were placed in 3000 g of 90° C. ion-exchanged water and extracted for 6 minutes. The resulting extract containing the tea leaves was subjected to solid-liquid separation (filtration) and then centrifuged at room temperature to obtain the supernatant as black tea extract (black tea extract). The tea polyphenol concentration of this black tea extract was measured using ferric tartrate absorptiometry and found to be 400 ppm.

(2. Preparation of Packaged Black Tea Beverage)
A mixture was prepared by adding appropriate amounts of L-ascorbic acid and sodium hydrogen carbonate to the black tea extract extracted from black tea leaves by the method described above in (1. Preparation of black tea extract). One or two of the three substances were added to this mixture at the concentrations shown in Table 11 below, to prepare each black tea beverage. Each black tea beverage was sterilized by the UHT method (at 120°C for 4 minutes or more), and then filled into a PET bottle to obtain each packaged black tea beverage (the packaged black tea beverages of Examples 22 to 26). A packaged black tea beverage of Comparative Example 13 was also prepared without adding any of the three substances.

(3. Sensory Evaluation Test)
The obtained packaged black tea beverages of Examples 22 to 26 and Comparative Example 13 were stored under 60°C conditions for 4 weeks. Thereafter, a sensory evaluation test was conducted by eight expert panels on the degree of suppression of the spicy odor and smoky odor of each of these packaged black tea beverages by the packaged black tea beverages. The degree of suppression of the spicy odor and smoky odor of the packaged black tea beverage of Comparative Example 13, which does not contain any of the three substances, was used as the standard, and the degree to which the spicy odor and smoky odor of the packaged black tea beverage of each Example was suppressed was evaluated according to the criteria (5-level) in Table 10 below. In order to reduce the variation in the evaluation of each panel, each panel evaluated the degree of suppression of the spicy odor and smoky odor of multiple types of packaged black tea beverages with known degrees of suppression of the spicy odor and smoky odor, and then the evaluation scores were compared to confirm that there was no significant deviation in the evaluation criteria of each panel, and it was also confirmed that the standard deviation of the evaluation scores of each panel was within 0.5.

For each of the packaged black tea beverages of Examples 22 to 26, the average score of the evaluation points of the eight expert panelists was calculated for the degree of suppression of spicy odor and smoky odor, and each average score was used as the evaluation of the packaged black tea beverage. In addition, the overall evaluation of each packaged black tea beverage was determined as follows: if the aforementioned average score was 2.5 points or more, it was designated as "Good", if it was 1.5 points or more but less than 2.5 points, it was designated as "Good", and if it was less than 1.5 points, it was designated as "Poor".

The evaluation results for each packaged black tea beverage of Examples 22 to 26 and Comparative Example 13 are shown in Table 11 below.

As can be seen from the results in Table 11, the use of any one or any two of the three substances suppressed the spicy and smoky odors, and in particular, the use of two substances in combination significantly suppressed the spicy and smoky odors.

The results of the above examples show that the three substances of the present invention, namely (E)-2-heptenal, (E,E)-2,4-heptadienal, and octanol, exhibit excellent suppression effects not only against stuffy odors, but also against spicy and smoky odors.

The present invention can provide a packaged black tea beverage in which the stuffy odor caused by heat sterilization or the like is suppressed, a method for producing the same, and a method for suppressing the stuffy odor of a packaged black tea beverage.

Claims (7)

In a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
The present invention provides a packaged black tea beverage for long-term storage, which contains one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal , and octanol at a concentration that satisfies at least one of the following (i) to (iii):
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb; The packaged black tea beverage according to claim 1, further satisfying any one, two or three of the following (I) to (III):
(I) containing (E)-2-heptenal and (E,E)-2,4-heptadienal;
and the ratio of the (E,E)-2,4-heptadienal concentration to the (E)-2-heptenal concentration in the packaged black tea beverage is 0.011 to 15;
(II) containing (E)-2-heptenal and octanol, and having a ratio of the octanol concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.11 to 150;
(III) containing (E,E)-2,4-heptadienal and octanol, and having a ratio of the octanol concentration to the (E,E)-2,4-heptadienal concentration in a packaged black tea beverage of 0.67 to 150; The packaged black tea beverage according to claim 1 or 2, wherein the pH of the beverage is 3.0 to 7.0. The packaged black tea beverage according to any one of claims 1 to 3, which is intended for sale heated. In the production of a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A method for producing a packaged black tea beverage for long-term storage, comprising a step of incorporating one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol at a concentration that satisfies at least one of the following (i) to (iii) :
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb; 6. The method for producing a packaged black tea beverage according to claim 5 , wherein the packaged black tea beverage further satisfies any one, two or three of the following (I) to (III):
(I) containing (E)-2-heptenal and (E,E)-2,4-heptadienal, and having a ratio of the (E,E)-2,4-heptadienal concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.011 to 15;
(II) containing (E)-2-heptenal and octanol, and having a ratio of the octanol concentration to the (E)-2-heptenal concentration in a packaged black tea beverage of 0.11 to 150;
(III) containing (E,E)-2,4-heptadienal and octanol, and having a ratio of the octanol concentration to the (E,E)-2,4-heptadienal concentration in a packaged black tea beverage of 0.67 to 150; In the production of a packaged black tea beverage containing 100 to 1000 ppm of tea polyphenols,
A method for suppressing stuffy odor in a packaged black tea beverage, comprising the step of incorporating one or more substances selected from (E)-2-heptenal, (E,E)-2,4-heptadienal and octanol in a concentration that satisfies at least one of the following (i) to (iii):
(i) (E)-2-heptenal is 5 to 450 ppb, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 750 ppb or less;
(ii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 5 to 75 ppb, and octanol is 750 ppb or less;
(iii) (E)-2-heptenal is 450 ppb or less, (E,E)-2,4-heptadienal is 75 ppb or less, and octanol is 50 to 750 ppb;