JP2024088295A - Packaged beverage with reduced light deterioration odor of tea beverage - Google Patents

Abstract

To provide a more general method for suppressing photodegradation odor of a packed green tea beverage, and to provide the packed green tea beverage with suppressed photodegradation odor, and a production method thereof, or the like.SOLUTION: A packed green tea beverage contains ascorbic acid and tocopherol.SELECTED DRAWING: None

Description

The present invention relates to a packaged green tea beverage and a manufacturing method thereof. More specifically, the present invention relates to a packaged green tea beverage in which deterioration odor due to photodegradation (hereinafter also referred to simply as "photodegradation odor") is suppressed, and a manufacturing method thereof.

In recent years, as people have become more health conscious, there has been growing attention on food and beverages that have health-promoting properties. In particular, green tea beverages contain healthy ingredients such as catechin and theanine, and consumer demand for these beverages is also increasing. In addition, because green tea beverages can be consumed anywhere and at any time, many packaged green tea beverages have been launched on the market.

However, there is a problem with packaged tea beverages in that they emit a photodegradation odor (i.e., a metallic odor, an oily odor, etc.) when exposed to light during distribution or sale. In relation to this problem, for example, Patent Document 1 discloses a method for producing instant green tea, which comprises the steps of preparing green tea leaves by drying the crude tea by heating at 140 to 160°C for 25 to 40 minutes, obtaining an extract of tea components from the green tea leaves using an aqueous extraction solvent containing 1600 to 2800 ppm of ascorbic acid, and removing the extraction solvent from the extract.

However, there has been a demand for a more versatile method for suppressing the light-induced odor of green tea beverages that can be used when using green tea leaves other than those that have been specifically treated as described in Patent Document 1.

JP 2005-058142 A

The object of the present invention is to provide a more versatile method for suppressing the light-deterioration odor of packaged green tea beverages, a packaged green tea beverage with suppressed light-deterioration odor, and a method for producing the same.

The inventors conducted intensive research to solve the above problems, and discovered that the light degradation odor can be suppressed by preparing a packaged green tea beverage so that it contains ascorbic acid and tocopherol, thus completing the present invention.

That is, according to the present invention, the following inventions are provided.
(1) A packaged green tea beverage containing ascorbic acid and tocopherol;
(2) The packaged green tea beverage according to (1) above, having an ascorbic acid concentration of 400 mg/L or more and a tocopherol concentration of 40 mg/L or more;
(3) A packaged green tea beverage according to the above (1) or (2), in which the ascorbic acid concentration is 1000 mg/L or less and the tocopherol concentration is 160 mg/L or less;
(4) A packaged green tea beverage according to any one of (1) to (3) above, having a pH of 7 or less.
(5) A packaged green tea beverage according to any one of (1) to (4) above, having an ascorbic acid concentration of 400 mg/L or more and a tocopherol concentration of 40 mg/L or more;
(6) A packaged green tea beverage according to any one of (1) to (5) above, having an ascorbic acid concentration of 1000 mg/L or less and a tocopherol concentration of 160 mg/L or less;
(7) A container-packed green tea beverage according to any one of (1) to (6) above, wherein the container is a transparent container.
(8) A method for producing a packaged green tea beverage, comprising preparing the packaged green tea beverage so as to contain ascorbic acid and tocopherol;
(9) The method for producing a packaged green tea beverage according to the above (8), wherein the content of ascorbic acid is adjusted to 400 mg/L or more and the content of tocopherol is adjusted to 40 mg/L or more;
(10) A method for producing a packaged green tea beverage according to the above (8) or (9), comprising preparing the beverage so that the ascorbic acid concentration is 1000 mg/L or less and the tocopherol concentration is 160 mg/L or less;
(11) A method for suppressing a light deterioration odor in a packaged green tea beverage, comprising preparing the packaged green tea beverage so as to contain ascorbic acid and tocopherol;

The present invention provides a more versatile method for suppressing the light-deterioration odor of packaged green tea beverages, a packaged green tea beverage with suppressed light-deterioration odor, and a method for producing the same.

The present invention relates to
[1] A packaged green tea beverage containing ascorbic acid and tocopherol; (hereinafter, also referred to as the "beverage of the present invention");
[2] A method for producing a packaged green tea beverage, comprising preparing the packaged green tea beverage so as to contain ascorbic acid and tocopherol (hereinafter also referred to as the "production method of the present invention");
[3] A method for suppressing a light-deterioration odor in a packaged green tea beverage, comprising preparing the packaged green tea beverage so as to contain ascorbic acid and tocopherol in the production of the packaged green tea beverage (hereinafter also referred to as the "suppression method of the present invention");
The embodiments include the following:

(Green tea extract)
Green tea beverages include green tea extracts. In this specification, "green tea extract" refers to an extract obtained by subjecting green tea leaves to an extraction process. In this specification, green tea extracts include the extract from green tea leaves (green tea extract) itself and processed products thereof (for example, green tea extracts obtained by concentrating or powdering the green tea extract). In the present invention, the extraction process may be any process in which green tea components are dissolved in the extraction solvent, and may also include, for example, a process in which ground tea leaves such as matcha are dissolved.

There are no particular limitations on the green tea leaves that can be used as the raw material for green tea extract, and examples include tea made from tea leaves obtained from the Chinese species (var. sinensis) or Assam species (var. assamica) of Camelliasinensis or hybrids thereof, and more specifically, sencha, gyokuro, matcha, kamairicha, fukamushicha, bancha, and hojicha. There are also no particular limitations on the tea season, shape of the tea leaves, place of origin, variety, and grade, and these can be appropriately determined by those skilled in the art. There are also no particular limitations on the conditions for extracting green tea leaves, such as the amount of tea leaves, amount of solvent, extraction temperature, and extraction time, and the conditions for extracting regular green tea leaves can be used.

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

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

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

One example of an extraction process is a method in which green tea leaves are soaked in water, stirred, and then filtered or centrifuged. The conditions for extraction, such as temperature and time, are not particularly limited and can be selected and set by a person skilled in the art depending on the type and amount of green tea leaves.

In preparing the green tea extract, a concentrate or purified product of green tea extract such as green tea extract or green tea powder may be used, for example, commercially available products such as Polyphenon (manufactured by Mitsui Norin Co., Ltd.), Sunphenon (manufactured by Taiyo Kagaku Co., Ltd.), and Theafuran (manufactured by Itoen Co., Ltd.) can be used. In addition, these green tea concentrates and purified green tea products may be used alone, as is, or dissolved or diluted with water, or may be used in combination with the green tea extract.

(Green tea beverage)
In the present invention, the "green tea beverage" is not particularly limited as long as it is a beverage containing a green tea extract, but a preferred example is a green tea beverage.

The tannin concentration in the beverage of the present invention may be, for example, 100 to 1000 mg/L, 200 to 900 mg/L, 200 to 800 mg/L, or 300 to 800 mg/L. In the present invention, the tannin concentration in the beverage can be adjusted, for example, by adjusting the amount of green tea leaves used when preparing the green tea extract or the amount of processed green tea extract used.

The tannin concentration in the beverage of the present invention can be measured using ferric tartrate absorptiometry (preferably the official method described in "Explanation of the Japanese Food Standard Analysis Manual, 5th Edition" edited by Japan Food Research Center (edited by Japan Food Research Center, Chuohoki, July 2001, p. 252)).

(Ascorbic Acid)
L-ascorbic acid is a type of water-soluble vitamin, and is a compound also known as vitamin C. The beverage of the present invention contains ascorbic acid. Examples of the ascorbic acid used in the present invention include ascorbic acid or a salt thereof, more specifically, L-ascorbic acid, sodium ascorbate, potassium ascorbate, calcium ascorbate, and the like. Note that ascorbic acid has the property of being oxidized to dehydroascorbic acid, which is further hydrolyzed and decomposed into diketogulonic acid.

The concentration of ascorbic acid in the beverage of the present invention is not particularly limited, but may be 400 mg/L or more. It may also be 600 mg/L or more, or 800 mg/L or more. From the viewpoint of obtaining a greater effect of suppressing light deterioration odor, the concentration of ascorbic acid is preferably 3000 mg/L or less, 2000 mg/L or less, more preferably 1200 mg/L or less, and even more preferably 1000 mg/L or less. These lower and upper limits can be combined in any desired manner.

Specific examples of suitable concentrations of ascorbic acid in the beverage of the present invention include 400 to 3000 mg/L, 400 to 2000 mg/L, 400 to 1000 mg/L, 600 to 3000 mg/L, 600 to 2000 mg/L, and 600 to 1000 mg/L.

In the present invention, the concentration of ascorbic acid in a beverage can be adjusted, for example, by adjusting the amount of ascorbic acid or a salt thereof contained in the beverage. Commercially available ascorbic acid or a salt thereof can be used.

In this specification, "concentration of ascorbic acid" means the concentration of ascorbic acid in a beverage. For example, when ascorbic acid is added to a beverage in the form of a salt, it means the concentration converted into the amount of ascorbic acid in the free form. The concentration of ascorbic acid in a beverage can be measured by a method using HPLC or a titration method.

(Tocopherol)
Tocopherol is a type of fat-soluble vitamin, and is a compound also known as vitamin E. The beverage of the present invention contains vitamin E. The tocopherol used in the present invention may be any of α-, β-, γ-, and δ-tocopherol, with the α-tocopherol being preferred, and may be any of d- or l-tocopherol, with the d-tocopherol being preferred, and the d-α-tocopherol being particularly preferred.

The tocopherol concentration in the beverage of the present invention is not particularly limited, but from the viewpoint of obtaining a greater effect of suppressing the light deterioration odor, it is preferably 40 mg/L or more, more preferably 80 mg/L or more. In addition, the tocopherol concentration is preferably 400 mg/L or less, 320 mg/L or less, or 160 mg/L or less. These lower and upper limits can be arbitrarily combined. When multiple types of tocopherol are used, the total concentration thereof is regarded as the tocopherol concentration in the present invention.

Specific examples of suitable tocopherol concentrations in the beverage of the present invention include 40 to 400 mg/L, 40 to 320 mg/L, 40 to 160 mg/L, 80 to 400 mg/L, 80 to 320 mg/L, and 80 to 160 mg/L.

In the present invention, the tocopherol concentration in the beverage can be adjusted, for example, by adjusting the amount of tocopherol contained in the beverage. Commercially available tocopherol can be used.

The concentration of tocopherols in beverages can be measured using HPLC. For example, impurities can be removed by heating and saponifying the sample with an alkali (potassium hydroxide), and the unsaponifiable matter can be extracted with a hexane-ethyl acetate mixture and measured using normal-phase high-performance liquid chromatography.

(Preferred concentration combination of ascorbic acid and tocopherol)
In the beverage of the present invention, preferred combinations of the content concentration of ascorbic acid and the content concentration of tocopherol are as follows:
A combination of an ascorbic acid concentration of 400 to 3000 mg/L and a tocopherol concentration of 40 to 400 mg/L;
A combination of an ascorbic acid concentration of 400 to 2000 mg/L and a tocopherol concentration of 40 to 320 mg/L;
A combination of an ascorbic acid concentration of 400 to 1000 mg/L and a tocopherol concentration of 40 to 160 mg/L;
A combination of an ascorbic acid concentration of 600 to 3000 mg/L and a tocopherol concentration of 80 to 400 mg/L;
A combination of an ascorbic acid concentration of 600 to 2000 mg/L and a tocopherol concentration of 80 to 320 mg/L; or
A combination of an ascorbic acid concentration of 600 to 1000 mg/L and a tocopherol concentration of 80 to 160 mg/L;
etc.

(Optional ingredients)
The packaged green tea beverage of the present invention comprises:
The composition may contain optional ingredients as long as they do not impair the effects of the present invention. Examples of such optional ingredients include one or more selected from the group consisting of acidulants, flavorings, colorants, sweeteners, preservatives, thickening stabilizers, emulsifiers, dietary fiber, pH adjusters, umami components, extracts, and bittering agents.

(pH)
The pH of the beverage of the present invention is not particularly limited, but from the viewpoint of increasing the problem of photodegradation odor and obtaining the full significance of the present invention, examples of the pH include 7 or less, preferably 6.8 or less, more preferably 6.5 or less, even more preferably 6 or less, and more preferably 5.8 or less. The lower limit of the pH includes, for example, 2, 4, 5, or 5.5. These lower and upper limits can be combined in any desired manner.

Suitable embodiments of the pH of the beverage of the present invention include, for example, 2 to 7, preferably 2 to 6.8, more preferably 2 to 6.5, even more preferably 2 to 6, and even more preferably 2 to 5.8. Other suitable embodiments of the pH of the beverage of the present invention include, for example, 4 to 7, preferably 4 to 6.8, more preferably 4 to 6.5, even more preferably 4 to 6, and even more preferably 4 to 5.8. Other suitable embodiments of the pH of the beverage of the present invention include, for example, 5 to 7, preferably 5 to 6.8, more preferably 5 to 6, and even more preferably 5 to 5.8. Other suitable embodiments of the pH of the beverage of the present invention include, for example, 5.5 to 7, preferably 5.5 to 6.8, more preferably 5.5 to 6, and even more preferably 5.5 to 5.8.

The pH of the beverage of the present invention can be adjusted by using a pH adjuster, etc., depending on the flavor design of the beverage of the present invention.

The pH of the beverage of the present invention refers to the pH at 20°C, and can be measured in the usual manner using a pH meter (for example, the main device "HM-41X" and the electrode "ST-5741C"; both manufactured by DKK-TOA Corporation).

(Beverage of the present invention)
The beverage of the present invention is not particularly limited so long as it is a packaged green tea beverage having an ascorbic acid concentration of 400 mg/L or more and a tocopherol concentration of 40 mg/L or more.

The beverage of the present invention is not different from a typical packaged green tea beverage in terms of the raw materials, manufacturing method, and manufacturing conditions used, except that it contains ascorbic acid and tocopherol.

The beverage of the present invention can be produced by adding ascorbic acid and tocopherol (preferably by preparing it in such a way) at any stage in the general production method of a "packaged green tea beverage."

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; bottle containers; and can containers. Transparent containers are preferred as containers for use in the present invention, as they are prone to producing a light-deterioration odor and therefore the significance of the present invention is enhanced.

The beverage of the present invention may not be heat sterilized, but may be heat sterilized from the viewpoint of improving shelf life. The method and conditions for heat sterilization may be the same as those normally used for beverages such as packaged beverages.

(Production method of the present invention)
The production method of the present invention is not particularly limited as long as it is a method for producing a packaged green tea beverage in which the packaged green tea beverage is prepared so as to contain ascorbic acid and tocopherol.

The beverage of the present invention can be produced by a general method for producing packaged green tea beverages, except that it is prepared so as to contain ascorbic acid and tocopherol. General methods for producing packaged green tea beverages are known, and for example, a packaged green tea beverage can be produced by preparing a green tea extract liquid, and then carrying out a blending process, a filling process, and a heat sterilization process. In producing the 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 to contain ascorbic acid and tocopherol" includes a method of adding "ascorbic acid or a salt thereof" and "tocopherol" to a green tea beverage during any step of the manufacturing process of a packaged green tea beverage so that the beverage of the present invention contains ascorbic acid and tocopherol, for example, a method of adding "ascorbic acid or a salt thereof" and "tocopherol" to a green tea extract.

The manufacturing method of the present invention may further contain, as optional ingredients, one or more selected from the group consisting of acidulants, flavorings, colorants, sweeteners, preservatives, thickening stabilizers, emulsifiers, dietary fiber, pH adjusters, umami components, extracts, and bittering agents.

In the manufacturing method of the present invention, the order in which the manufacturing ingredients are mixed is not particularly limited as long as the beverage of the present invention can be manufactured. After preparing a liquid containing the manufacturing ingredients, the liquid can be filled into a container and sealed to obtain the beverage of the present invention.

(Heat sterilization)
The production method of the present invention may include a step of heat sterilizing the green tea beverage. As the heat sterilization method, a normal heat sterilization method for packaged beverages can be used without any particular limitation. 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 that cannot be retorted, 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 light deterioration odor in a packaged green tea beverage by preparing the packaged green tea beverage so that it contains ascorbic acid and tocopherol during production of the packaged green tea beverage.

The method for "preparing the composition so as to contain ascorbic acid and tocopherol" can be the same as that described above in (Production method of the present invention).

(Packaged green tea beverage with reduced light deterioration odor)
The beverage of the present invention is a packaged green tea beverage in which light-deterioration odor is suppressed. In the present invention, the term "light-deterioration odor" refers to a light-deterioration odor (i.e., a metallic odor, an oily odor, etc.) that occurs when a packaged green tea beverage is exposed to light.

In this specification, examples of packaged green tea beverages with "suppressed light-deterioration odor" include beverages with suppressed light-deterioration odor compared to beverages (hereinafter also referred to as "control beverages") produced using the same ingredients at the same final concentrations and by the same manufacturing method, except that ascorbic acid and tocopherol are not added. Examples of the control beverage include packaged green tea beverages with an ascorbic acid concentration of less than 20 mg/L (preferably less than 10 mg/L) and a tocopherol concentration of less than 1.5 mg/L (preferably less than 1 mg/L).

A trained panel can easily and clearly determine the level of photodegradation odor in a given green tea beverage and how that level compares to the control beverage of the present invention (e.g., whether and to what extent the photodegradation odor is suppressed).

The evaluation criteria for the photodegradation odor and the method of summarizing the evaluations among the panels can be general methods. The number of panels evaluating the degree of photodegradation odor in a beverage may be one, but from the viewpoint of obtaining a more objective evaluation, the lower limit of the number of panels can be, for example, three or more, preferably five or more, and from the viewpoint of performing the evaluation test more simply, the upper limit of the number of panels can be, for example, seven or less. When the panel is two or more people, the evaluation of the degree of photodegradation odor in a beverage may be performed by adopting the average evaluation of the degree of photodegradation odor in the beverage by all the panels. For example, when an evaluation score is assigned to each evaluation criterion, the average evaluation score of all the panels may be adopted as the evaluation of the degree of photodegradation odor in the beverage. As described above, when the average evaluation score is adopted, the value obtained by rounding the average to the first decimal place may be adopted. In addition, when the panel is two or more people, in order to reduce the variation in the evaluations of each panel, it is preferable to carry out the work of standardizing the evaluation criteria so that the evaluation criteria of each panel are as consistent as possible before the actual sensory evaluation test is performed. Such standardization work may involve having the panels share a common understanding of the level of the photodegradation odor, which corresponds to the evaluation point when the level of the photodegradation odor is at its highest, before evaluating each sample beverage. In addition, it is preferable that such prior standardization work regarding evaluation criteria ensures that, for example, when the evaluation points are on a seven-point scale of 1, 2, 3, 4, 5, 6, and 7 points, the standard deviation of the evaluation of the level of the photodegradation odor by each panel is within 0.5.

The degree of suppression of the light-degraded odor in a certain packaged green tea beverage can be evaluated, for example, by a method similar to, and preferably by, the sensory evaluation method described in Test 2 of the Examples below. More specifically, the degree of the light-degraded odor of the sample beverage and the degree of the deterioration odor of the control beverage are evaluated on a seven-point scale, respectively, including "7 points: no light-degraded odor at all," "6 points: almost no light-degraded odor," "5 points: slight light-degraded odor," "4 points: some light-degraded odor," "3 points: light-degraded odor," "2 points: strong light-degraded odor," and "1 point: very strong light-degraded odor." For example, the evaluation scores (average values rounded to one decimal place) of multiple panels can be calculated for each. The numerical value obtained by subtracting the evaluation score of the light-degraded odor of the sample beverage from the evaluation score of the light-degraded odor of the control beverage (in this specification, such a numerical value is also referred to as "light-degraded odor (relative)") can be used as the evaluation score of the degree to which the light-degraded odor in the sample beverage is suppressed. Beverages with a photodegradation odor (relative) of 0.1 or more (preferably 0.2 or more, more preferably 0.4 or more, even more preferably 0.7 or more, more preferably 0.8 or more, even more preferably 1 or more, more preferably 1.2 or more, even more preferably 1.4 or more) are examples of beverages with reduced photodegradation odor.

The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

Test 1. [Effect of product pH on light deterioration odor]
The following experiment was carried out to investigate how the product pH of a packaged green tea beverage affects the level of light deterioration odor.

1. Preparation of Green Tea Beverages
Green tea leaves (sencha) were added to 30 times their weight of hot water (70°C) and extracted for 6 minutes, followed by solid-liquid separation to prepare a green tea extract. Sodium bicarbonate (sodium hydrogen carbonate) was added to this green tea extract to adjust the pH to that shown in Table 2, and then the final tea leaf content concentration was adjusted to that shown in Table 2. These green tea extracts were subjected to UHT (ultra-high temperature) sterilization, and then each was filled into a transparent plastic container to prepare each of the sample beverages of Test Examples 1 and 2.

The sample beverage was left to stand for 14 days under conditions of 3,000 lux illumination and 10°C.

(2. Sensory Evaluation Test)
A sensory evaluation test was conducted by five trained expert panelists on the level of light degradation odor (i.e., metallic odor, oily odor) of the obtained sample beverages of Test Examples 1 and 2, using the seven-point evaluation criteria as shown in Table 1. The difference in the level of light degradation odor between 1 point and 2 points, between 2 points and 3 points, between 3 points and 4 points, between 4 points and 5 points, between 5 points and 6 points, and between 6 points and 7 points was set to the same level.
The degree of light deterioration odor in the sample beverage of each test example was evaluated by rounding off the average score of each panel to one decimal place.

In addition, when the evaluation criteria in Table 1 are, for example, 5 points or less, it can be determined that there is a problem with light degradation odor.

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

As can be seen from the results in Table 2, although a light degradation odor was detected in Test Example 1, where the product pH was 6.8, a significantly stronger light degradation odor was detected in Test Example 2, where the product pH was lower, 5.5. These results demonstrate that the light degradation odor, which is the subject of the present invention, becomes significantly stronger when the pH is lower.

Test 2. [Effect of L-ascorbic acid and tocopherol on light deterioration odor at low pH]
The following experiment was carried out to investigate the effect of L-ascorbic acid and tocopherol on the light deterioration odor of a low-pH packaged green tea beverage.

1. Preparation of Green Tea Beverages
Green tea leaves (sencha) were added to 30 times the weight of hot water (70°C), extracted for 6 minutes, and solid-liquid separation was performed to prepare a green tea extract. L-ascorbic acid (vitamin C), tocopherol (vitamin E), or both were added to this green tea extract to obtain the content concentrations shown in Tables 3 to 5, and then sodium bicarbonate (sodium bicarbonate) was added to adjust the pH to 5.5, and the final tea leaf content concentrations were adjusted to the tea leaf content concentrations shown in Tables 3 to 5. These green tea extracts were subjected to UHT (ultra-high temperature) sterilization and then filled into transparent plastic containers to prepare each of the sample beverages of Test Examples 3 to 19. As a control beverage, the sample beverage of Test Example 2, which did not contain either L-ascorbic acid or tocopherol, was prepared.

The sample beverages of test examples 2 to 19 were left to stand for 14 days under conditions of an illumination intensity of 3,000 lux and 10°C.

(2. Sensory Evaluation Test)
The degree of light deterioration odor (i.e., metallic odor, oily odor) of the sample beverages of Test Examples 2 to 19 obtained was subjected to a sensory evaluation test by a trained expert panel of five members using the seven-level evaluation criteria as described in Table 1 above.
The level of light-deterioration odor in each sample beverage was determined by rounding the average of the evaluation scores of each panel to one decimal place (the "average evaluation value"). The average evaluation value of the control beverage, sample beverage of Test Example 2, from the average evaluation value of each sample beverage of Test Examples 3 to 19 is shown in Tables 3 to 5 as the level of suppression of light-deterioration odor in each sample beverage (also shown as "light-deterioration odor (relative)").

Table 3 shows the results when L-ascorbic acid (vitamin C) was added, while Tables 4 and 5 show the results when both L-ascorbic acid (vitamin C) and tocopherol (vitamin E) were added. Tables 4 and 5 also show the "value" of the degree of suppression of light-deterioration odor when L-ascorbic acid alone is used at the concentration included in that test example (i.e., the value of the light-deterioration odor (relative) when L-ascorbic acid is used alone). Using test example 15 in Table 5 as an example, the value of the light-deterioration odor (relative) when 600 mg/L of L-ascorbic acid is used alone ("1.3"; test example 4 in Table 3) is shown as "light-deterioration odor (relative) when L-ascorbic acid is used alone."

The results in Table 3 show that when L-ascorbic acid is used alone, the light degradation odor is suppressed to some extent when the L-ascorbic acid content is 600 mg/L or more.

The results in Tables 4 and 5 show that the combined use of L-ascorbic acid and tocopherol has a significant inhibitory effect on the light-induced odor of green tea beverages compared to the use of L-ascorbic acid alone.

The results in Tables 4 and 5 also show that the preferred combinations of ascorbic acid and tocopherol concentrations are "a combination of an ascorbic acid concentration of 400 to 1000 mg/L and a tocopherol concentration of 40 to 160 mg/L" and "a combination of an ascorbic acid concentration of 600 to 1000 mg/L and a tocopherol concentration of 80 to 160 mg/L."

Test 3. [Effect of L-ascorbic acid and tocopherol on light deterioration odor at high pH]
The following experiment was carried out to investigate the effect of L-ascorbic acid and tocopherol on the light deterioration odor of a high-pH packaged green tea beverage.

1. Preparation of Green Tea Beverages
Green tea leaves (sencha) were added to 30 times the weight of hot water (70°C), extracted for 6 minutes, and solid-liquid separation was performed to prepare a green tea extract. L-ascorbic acid (vitamin C), tocopherol (vitamin E), or both were added to this green tea extract to obtain the content concentrations shown in Table 6, and then sodium bicarbonate (sodium bicarbonate) was added to adjust the pH to 6.8, and the final tea leaf content concentration was adjusted to the tea leaf content concentration shown in Table 6. These green tea extracts were subjected to UHT (ultra-high temperature) sterilization and then filled into transparent plastic containers to prepare each of the sample beverages of Test Examples 20 to 24. As a control beverage, the sample beverage of Test Example 1, which did not contain either L-ascorbic acid or tocopherol, was prepared.

The sample beverages of Test Examples 1 and 20 to 24 were left to stand for 14 days under conditions of an illumination intensity of 3,000 lux and 10°C.

(2. Sensory Evaluation Test)
The degree of light deterioration odor (i.e., metallic odor, oily odor) of the sample beverages of Test Examples 1 and 20 to 24 obtained was subjected to a sensory evaluation test by a trained expert panel of five members using the seven-level evaluation criteria as described in Table 1 above.
The level of light-deterioration odor for each sample beverage was determined by rounding the average of the evaluation scores of each panel to one decimal place (the "average evaluation value"). The average evaluation value for the control beverage, sample beverage of Test Example 1, was subtracted from the average evaluation value for each sample beverage of Test Examples 1 and 20 to 24, and this value is shown in Table 6 as the level of suppression of light-deterioration odor for each sample beverage (also shown as "light-deterioration odor (relative)").

The results in Table 6 show that the combined use of L-ascorbic acid and tocopherol has a suppressive effect against light-deterioration odor, even in high-pH packaged green tea beverages.

In addition, when the concentrations of L-ascorbic acid and tocopherol are the same and the pH is 5.5 and 6.8, it was shown that the pH of 5.5 had a higher suppression effect against light-degraded odor (see "Light-degraded odor (relative) for test example at pH 5.5" at the bottom of Table 6). For example, when 400 mg/L of L-ascorbic acid and 160 mg/L of tocopherol were used in combination, the "light-degraded odor (relative)" was "1.6" at pH 6.8 (Test Example 22 in Table 6), whereas the "light-degraded odor (relative)" was "2.5" at pH 5.5 (Test Example 12 in Table 4). These results show that at low pH such as pH 5.5, the combined use of L-ascorbic acid and tocopherol provides a more significant suppression effect against light-degraded odor.

The present invention provides a more versatile method for suppressing the light-deterioration odor of packaged green tea beverages, a packaged green tea beverage with suppressed light-deterioration odor, and a method for producing the same.

Claims (11)

A packaged green tea beverage containing ascorbic acid and tocopherol. The packaged green tea beverage according to claim 1, wherein the ascorbic acid concentration is 400 mg/L or more and the tocopherol concentration is 40 mg/L or more. The packaged green tea beverage according to claim 2, wherein the ascorbic acid concentration is 1000 mg/L or less and the tocopherol concentration is 160 mg/L or less. The packaged green tea beverage according to claim 1, having a pH of 7 or less. The packaged green tea beverage according to claim 4, wherein the ascorbic acid concentration is 400 mg/L or more and the tocopherol concentration is 40 mg/L or more. The packaged green tea beverage according to claim 5, wherein the ascorbic acid concentration is 1000 mg/L or less and the tocopherol concentration is 160 mg/L or less. The container-packed green tea beverage according to any one of claims 1 to 6, wherein the container is a transparent container. A method for producing a packaged green tea beverage, comprising preparing the packaged green tea beverage so that it contains ascorbic acid and tocopherol. The method for producing a packaged green tea beverage according to claim 8, wherein the ascorbic acid concentration is adjusted to 400 mg/L or more and the tocopherol concentration is adjusted to 40 mg/L or more. The method for producing a packaged green tea beverage according to claim 9, wherein the beverage is prepared so that the ascorbic acid concentration is 1000 mg/L or less and the tocopherol concentration is 160 mg/L or less. A method for suppressing light-deterioration odor in a packaged green tea beverage, comprising preparing the beverage to contain ascorbic acid and tocopherol during the manufacture of the packaged green tea beverage.