JP7709399B2 - Packaged green tea beverage containing high concentrations of theanine - Google Patents

Description

The present invention relates to a packaged green tea beverage containing a high concentration of theanine.

Green tea beverages are widely enjoyed as a luxury item, and are available not only as freshly brewed green tea from tea leaves, but also as packaged beverages sealed in containers such as cans, PET bottles, and paper containers.
In particular, in recent years, the market for healthy green tea has expanded due to the growing health consciousness of consumers, and packaged green tea beverages with increased amounts of functional ingredients derived from tea have attracted attention. For example, theanine, a umami ingredient found in high-quality green tea such as gyokuro, is known to be effective in improving sleep quality and to have an anti-stress effect, and Patent Documents 1 to 3 propose green tea beverages containing theanine.

JP 2014-68634 A JP 2018-78912 A International Publication WO2006/033300

The inventors discovered that by adding a large amount of L-theanine, which is found in large amounts in gyokuro, a high-quality green tea, the umami flavor of the green tea beverage is enhanced, but the lingering aroma unique to green tea beverages becomes less noticeable and the balance between the green aroma and the fire aroma is lost.

In light of this situation, the objective of the present invention is to provide a packaged green tea beverage that contains a high concentration of L-theanine, has a good lingering aroma, and has a good balance of green and fire aromas.

As a result of intensive research into the above-mentioned problems, the inventors discovered that the above-mentioned problems could be solved by adding specific amounts of glyceroglycolipids and nonanal to a green tea beverage, and thus completed the present invention.

The present invention includes, but is not limited to, the following aspects.
[1] A packaged green tea beverage having an L-theanine content of 100 to 2200 ppm, a glyceroglycolipid content of 0.2 to 30 ppm, and a nonanal content of 0.5 to 10 ppb.
[2] The beverage according to [1], having a catechin content of 1,200 ppm or less.
[3] The beverage according to [1] or [2], wherein the content of glyceroglycolipids is 1 to 20 ppm.
[4] The beverage according to any one of [1] to [3], which contains green tea powder.
[5] A method for producing the beverage according to any one of [1] to [4], comprising the step of adjusting the L-theanine content to 100 to 2200 ppm and the glyceroglycolipid content to 0.2 to 30 ppm.

According to the present invention, it is possible to improve the lingering pleasant aroma characteristic of green tea beverages that contain a high concentration of L-theanine.

The present invention relates to a green tea beverage. In this specification, "green tea beverage" refers to a beverage prepared by blending an extract of green tea leaves, and one preferred embodiment of the green tea beverage of the present invention is a beverage having green tea extract as the main component. Here, a beverage having green tea extract as the main component refers to a beverage in which a description related to green tea, such as "green tea" or "green tea extract," is listed at the top of the ingredients list as specified in the Food Labeling Act (enforced in April 2015). Preferably, the beverage has a description related to green tea listed first or second in the ingredients list, and more preferably, it is a beverage in which a description related to green tea is listed first.

Green tea leaves, which are the raw material for green tea beverages, include tea leaves selected from the genus Camellia, such as Camellia sinensis, and hybrids thereof, and are classified as non-fermented teas (e.g., sencha, bancha, tencha, kamairicha, kukicha, bocha, budcha, etc.). Examples of Camellia sinensis include C. sinensis var. sinensis (including the Yabukita variety), C. sinensis var. assamica, etc.

In general, many of the aroma components in green tea beverages are unstable and gradually deteriorate due to oxygen, light, heat, etc., and over long periods of storage, the original flavor and aroma of green tea disappears and an unpleasant taste or odor (deteriorated odor) develops. The inventors have discovered that in green tea beverages containing high concentrations of L-theanine, the lingering aroma of the original green tea is reduced, and the balance between the green aroma and the fire aroma is lost. Here, a reduction in the lingering aroma of a green tea beverage in this specification refers to a reduction in the aroma that lingers as an aftertaste, particularly from the middle to the end.

L-Theanine The green tea beverage of the present invention contains 100 to 2200 ppm of L-theanine. As described above, when a high concentration of L-theanine is added to a green tea beverage, the lingering aroma of the green tea beverage is reduced. However, by blending glyceroglycolipids based on the present invention, the lingering aroma of the green tea beverage can be enhanced. The L-theanine content of the green tea beverage targeted by the present invention is 100 ppm or more, preferably 130 ppm or more, more preferably 150 ppm or more, and even more preferably 200 ppm or more. In addition, from the viewpoint of the palatability of the green tea beverage, the L-theanine content is 2200 ppm or less, preferably 1800 ppm or less, more preferably 1600 ppm or less, and even more preferably 1500 ppm or less. In this specification, "ppm" and "ppb" refer to the concentration (mg/L, μg/L) of each component contained in a unit volume of a green tea beverage.

There are no particular limitations on the method of adding L-theanine. Refined L-theanine products (including crudely refined products), extracts of tea leaves containing high concentrations of L-theanine, or tea leaf powder such as matcha may be added to the green tea beverage, but in order to efficiently add a high concentration of theanine, it is preferable to add a refined L-theanine product. Commercially available L-theanine products include Suntheanine (trademark: Taiyo Kagaku, L-theanine purity 98% or more). The content of L-theanine in the green tea beverage can be quantified using an amino acid analyzer.

Glyceroglycolipids The green tea beverage of the present invention contains 0.2 to 30 ppm of glyceroglycolipids, thereby preventing a reduction in the lingering aroma caused by L-theanine. In the present invention, the content of glyceroglycolipids is preferably 0.4 ppm or more, more preferably 0.8 ppm or more, even more preferably 1.0 ppm or more, and even more preferably 1.2 ppm or more. On the other hand, from the viewpoint of palatability, the content of glyceroglycolipids is preferably 20 ppm or less, more preferably 15 ppm or less, and even more preferably 13 ppm or less.

Glyceroglycolipids are glycolipids in which a sugar chain consisting of 1 to 3 monosaccharides is ester-bonded to diacylglycerol. Examples of monosaccharides constituting the sugar chain contained in glyceroglycolipids include galactose, glucose, mannose, fructose, xylose, arabinose, fucose, quinovose, rhamnose, and sulfoquinovose, and examples of the acyl group include saturated or unsaturated linear or branched fatty acid residues having 6 to 24 carbon atoms. Specific examples include linolenic acid, linoleic acid, oleic acid, stearic acid, and palmitic acid. The content of glyceroglycolipids in the present invention refers to the total content of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG). In beverages, glyceroglycolipids can be considered to exist as a colloidal dispersion system.

To adjust the glyceroglycolipid content in a green tea beverage, for example, a refined glyceroglycolipid product may be added. The type of tea leaves and extraction method may be adjusted to adjust the glyceroglycolipid content in a green tea beverage to 0.2 to 30 ppm. For example, the amount of glyceroglycolipid may be adjusted by mixing two or more types of green tea extracts, or it may be adjusted by adding powdered tea instead of green tea extract. For the addition of glyceroglycolipid to a green tea beverage, for example, the methods described in International Publication WO2009/116538 and JP2017-74014 may be referred to.

When powdered tea is added to adjust the glyceroglycolipid content, the amount of powdered tea is preferably 0.001% or more, more preferably 0.005% or more, and even more preferably 0.01% or more. If too much powdered tea is added, it will have a significant effect on not only the aroma but also the taste of the green tea beverage, so the amount is preferably 0.8% or less, more preferably 0.5% or less, and even more preferably 0.15% or less. When powdered tea is added to a green tea beverage, the turbidity of the green tea beverage increases, and this can be measured using the turbidity (OD680) expressed as absorbance at 680 nm. Therefore, the turbidity (OD680) is preferably 0.1 or more, more preferably 0.15, and even more preferably 0.2 or more, with the upper limit being preferably 10 or less, more preferably 5 or less, even more preferably 1 or less, and most preferably 0.8 or less. Turbidity is indicated by absorbance at 680 nm (OD680) and can be measured using a general spectrophotometer according to standard methods. If the turbidity of the sample is too high and the measured value is not stable, the sample may be diluted before measuring the turbidity and the turbidity may be calculated by multiplying by the dilution factor. In the present invention, the average particle size of the powdered tea is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and even more preferably 1.0 to 20 μm.

Nonanal In the present invention, the reduction in the aftertaste of aroma is prevented, and thus the balance between the green aroma and the fire aroma is improved, and the inherent aroma of green tea, particularly the fresh aroma of a green tea beverage, can be perceived relatively strongly. Here, an example of the fresh aroma of a green tea beverage is "cucumber aroma." The cucumber aroma is a characteristic aroma of Gyokuro, a high-quality tea, and the aroma component that is the source of the cucumber aroma is nonanal, a volatile aldehyde. The nonanal content of the green tea beverage according to the present invention is 0.
In a preferred embodiment of the present invention, the nonanal content is preferably 1.0 to 8.0 ppb, more preferably 1.5 to 6.0 ppb, and even more preferably 2.0 to 5.0 ppb.

The beverage according to the present invention is a green tea beverage prepared by blending an extract of green tea leaves, and also contains catechins. If the content of catechins is too high, the bitterness and astringency of the catechins may impair the taste of the green tea beverage. Therefore, the content of catechins in the green tea beverage of the present invention is preferably 1200 ppm or less, more preferably 1100 ppm or less. The lower limit of the content of catechins is, for example, 50 ppm or more, preferably 100 ppm or more, and more preferably 300 ppm or more.

In this specification, "catechins" refers to catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (Cg), epicatechin gallate (ECg), gallocatechin gallate (GCg), and epigallocatechin gallate (EGCg), and "catechin content" refers to the total amount of these eight types. The concentration of catechins in a beverage can be quantified by high performance liquid chromatography (HPLC) using a reverse phase column.

In addition to the above components, the green tea beverage of the present invention can contain antioxidants such as ascorbic acid and sodium ascorbate. The addition of an antioxidant can prevent browning during and after the production process of the green tea beverage and the generation of unpleasant odors associated with browning, which, together with the effect of the present invention, can improve the flavor of the green tea beverage. The amount of antioxidant can be appropriately selected depending on the type of antioxidant; for example, in the case of L-ascorbic acid, it is about 0.02 to 0.08% by weight.

The beverage of the present invention is a packaged green tea beverage that can be stored for a long period of time at room temperature, and is usually pH-adjusted using a pH adjuster such as sodium bicarbonate to suppress a decrease in pH during storage. The pH of the packaged green tea beverage is preferably about 5.5 to 7.0, more preferably about 5.8 to 6.5. A green tea beverage adjusted to such a pH is less likely to have the aroma of a green tea beverage than a green tea beverage that is not pH-adjusted (e.g., a green tea beverage brewed in a teapot), but the green tea beverage of the present invention suppresses the decrease in the lingering aroma and allows the fresh flavor characteristic of green tea beverages to be strongly perceived. Due to the remarkable effect of the present invention, a pH-adjusted green tea beverage is one example of a preferred embodiment of the present invention. Here, the pH in this specification refers to the value measured by measuring 100 mL of the liquid beverage into a 200 mL beaker, adjusting the temperature to 20°C, and measuring it with a pH meter.

In addition to the above-mentioned components, the tea beverage of the present invention may contain various additives as necessary, provided that the intended object of the present invention is not deviated from. Examples of various additives include sweeteners, colorants, emulsifiers, preservatives, vitamins, extracts, flavorings, etc., which may be used alone or in combination. From the viewpoint of being able to significantly exert the effects of the present invention, it is preferable for the green tea beverage to be free of sweeteners and flavorings.

In a preferred embodiment, the present invention relates to a packaged green tea beverage that can be stored for a long period of time at room temperature. In this specification, the packaged green tea beverage refers to a beverage that is packaged in a container and sealed, and includes RTD beverages (RTD = Ready To Drink: beverages packaged in containers such as PET bottles, cans, bottles, and paper that can be consumed immediately after opening the lid). The packaged green tea beverage of the present invention also includes dilution-type beverages in which a concentrated liquid is packaged in a container, sealed, and diluted with water or the like when consumed, and in this case, the contents of L-theanine, nonanal, etc. refer to beverages that are within the above-mentioned ranges when diluted.

The container may be made of any of the materials typically used for beverage containers, including metal containers such as aluminum cans and steel cans, resin containers such as PET bottles, glass bottles, and paper containers. In a particularly preferred embodiment, the beverage container according to the present invention is made of a transparent resin, from the viewpoint of effectively reducing the deterioration odor caused by light, oxygen, etc. The container capacity is not particularly limited, but is about 100 to 2000 mL, preferably 200 to 2000 mL, and more preferably 350 to 2000 mL.

The container-packed beverage according to the present invention is a beverage that can be stored for a long period of time at room temperature. The beverage preparation may be filled into a container after heat sterilization, or may be filled into a container and then heat sterilized. In addition, in the present invention, aseptic filling at low temperature or the like may be performed. The conditions for heat sterilization are not particularly limited, but a treatment specified in the Food Sanitation Act may be performed. For example, in the case of canned beverages, retort sterilization (e.g., heat sterilization at 121°C for 7 minutes while applying appropriate pressure) may be performed in the case of resin containers, UHT sterilization (e.g., holding the beverage composition at 120 to 150°C for 1 to several tens of seconds) may be performed, but hot packs, membrane sterilization, etc. may be used as necessary. For example, in the case of retort sterilization, the treatment may be performed at 110 to 130°C for about 10 to 30 minutes, preferably at 120 to 125°C for about 10 to 20 minutes, and in the case of UHT sterilization, the treatment may be performed at 120 to 150°C for about 1 to 120 seconds, preferably at 130 to 145°C for about 30 to 120 seconds.

The details of the present invention will be specifically explained below with reference to experimental examples, but the present invention is not limited thereto. Furthermore, in this specification, unless otherwise specified, concentrations and the like are based on mass (weight), and numerical ranges are described as including their endpoints.

Quantitative determination of each component Each component contained in the green tea beverage was quantified as follows. When insoluble solids such as powdered tea are contained, the insoluble solids may be removed by centrifugation or filtration before analyzing each component. Centrifugation can be performed at 3000 rpm for 10 minutes, and filtration can be performed using a membrane filter (pore size: 0.45 μm, Tosk).
(1) L-Theanine L-theanine was quantified using HPLC. Theanine (special grade reagent) manufactured by Fujifilm Wako Pure Chemical Industries was used as a standard for creating a calibration curve. The HPLC measurement conditions are as follows:
HPLC device: Waters Amino Acid Analyzer 2695
Column: AccQ-Tag column (3.9 mm x 150 mm)
Column temperature: 40°C
・Mobile phase A: AccQ-TagA (pH 5.8)
Mobile phase B: acetonitrile Mobile phase C: water-methanol (90:10)
Detection: EX 250 nm EM 395 nm Gain 100
・Injection volume: 5μL
・Gradient program:
Time (min) Flow rate (ml/min) %A %B %C
0 1 100 0 0
1 1 99 1 0
16 1 97 3 0
25 1 94 6 0
35 1 86 14 0
40 1 86 14 0
50 1 82 18 0
51 1 0 60 40
54 1 100 0 0
75 1 0 60 40
110 0 0 60 40
(2) Glyceroglycolipids The fraction was pressure filtered using an ultrafiltration membrane (Millipore, Biomax PBMK Ultrafiltration Disk, polyethersulfone, 300,000 NMWL) and the components on the membrane were collected to obtain a fraction with a molecular weight of 300,000 or more. This was dissolved in water, acidified with hydrochloric acid, and then subjected to liquid-liquid distribution with ethyl acetate, of which the ethyl acetate layer was collected (3 times in total). This liquid was concentrated and subjected to reverse phase chromatography to perform quantitative analysis of glyceroglycolipids.

Avanti's monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) were used as standards for quantitative analysis. When the MGDG standard was analyzed, it was divided into two major peaks, so a calibration curve was created using both peaks. The analysis conditions were as follows.
・Reverse phase column: TSK-GEL (TOSOH, inner diameter 4.6 mm x length 150 mm)
Sample injection volume: 10 μl
・Flow rate: 1.0ml/min.
・RI detector: SHIMADZU RIA-10A
Eluent: 95% methanol Temperature: 40°C
(3) Nonanal Nonanal in each sample was quantified using GC/MS. Specifically, the sample solution was directly placed in a 20 ml glass crimp vial (diameter 18 mm, manufactured by AMR), sealed with a PTFE septum-equipped crimp cap (manufactured by AMR), and components were extracted by solid phase microextraction (SPME). Quantification was performed by drawing a chromatogram from the GC/MS analysis results and using the area of the detected peaks by standard addition method or internal standard method. The instruments and conditions used are shown below.
・Solid-phase microextraction fiber: SPME Arrow (1.1 mm, Phase Carbon WR/PDMS, Thickness: 120 μm, Length 20 mm, Pal System)
・Autosampler: TriPlus RSH (Thermo Fisher Scientific)
・Cold storage temperature for samples awaiting analysis: 1 to 4°C
・Preheating and agitation device: Agitator
Pre-heating: 45°C for 3 minutes Pre-heating stirring: 300 rpm
・Volatile component extraction device: Heatex Stirrer
Extraction of volatile components: 45°C for 20 minutes Stirring during extraction of volatile components: 800 rpm
Desorption time of volatile components: 2 minutes Fiber depth during desorption of volatile components: 50 mm
・GC oven: Trace 1300 (manufactured by Thermo Fisher Scientific)
Column: DB-WAX UI (60 m × 0.25 mm i.d. × df = 0.50 μm, Agilent Technologies); however, deactivated fused silica tubes (0.25 mm i.d., Agilent Technologies) were connected to the precolumn (length 1.5 m) and postcolumn (length 1.0 m). GC temperature conditions: 40°C (5 min) → 3°C/min → 190°C → 5°C/min → 250°C (15 min)
Equilibration waiting time: 0.5 min. Carrier gas: Helium, 1.0 ml/min, constant flow rate mode. Injection: Splitless method. Inlet temperature: 250° C.
・Cryofocus function: Liquid nitrogen cooling device and heater (using PTV injector, manufactured by Thermo Fisher Scientific) installed in the pre-column ・Cryofocus conditions: -95°C (2.5 minutes) → 14.5°C/min → 250°C (until the end of analysis)
Mass spectrometer: Q Exactive GC Orbitrap MS system (Thermo Fisher Scientific)
Ionization method: EI (70 eV)
Measurement method: Orbitrap scan measurement Runtime: 3.5-80.0 minutes Polarity: positive
・Resolution: 60000
・AGC target: 3e6
Scan range: m/z 35-500
Quantitative ion: m/z 81.06987 (if the peak shape or sensitivity is not good, change the AGC target or use SIM mode)
MS Range: 5 to 10 ppm (if there is a mass deviation, the m/z of the above quantification ion is appropriately shifted)
(4) Catechins The catechin content of the green tea beverage was analyzed by HPLC. Catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate (Kurita Water Industries, high purity reagent) were used as standards for quantitative analysis. The HPLC measurement conditions are as follows:
・HPLC equipment: TOSOH HPLC system LC8020 model II
Column: TSKgel ODS80T sQA (4.6 mm x 150 mm)
Column temperature: 40°C
Mobile phase A: water-acetonitrile-trifluoroacetic acid (90:10:0.05)
Mobile phase B: water-acetonitrile-trifluoroacetic acid (20:80:0.05)
Detection: UV 275 nm
・Injection volume: 20μL
・Flow rate: 1.0mL/min.
Gradient program (volume %):
Time (min) %A %B
0 100 0
5 92 8
11 90 10
21 90 10
22 0 100
29 0 100
30 100 0
Experiment 1: Production and evaluation of green tea beverage (reference example)
A base green tea beverage was prepared from strongly pasteurized sencha, and L-theanine (manufactured by Taiyo Kagaku, purity 99.4%) was added to the base green tea beverage to produce a packaged green tea beverage containing theanine in the amount shown in the table below. All of the green tea beverages prepared in this experiment had a glyceroglycolipid content of about 70 ppb, a nonanal content of about 1 ppb, and a catechin content of about 400 ppm (pH: about 6.0).

Next, the obtained green tea beverages were subjected to a sensory evaluation by a panel of six experts based on the following criteria: Using sample a as the standard, the expert panel evaluated the lingering aroma of each of the green tea beverage samples, and then the panel members discussed and decided on the evaluation.
◯: The aroma has a lingering scent equivalent to that of sample a. △: The aroma has a slightly inferior lingering scent compared to the standard. ×: The aroma has a significantly inferior lingering scent compared to the standard.

The evaluation results are shown in Table 1. It was found that green tea beverages containing theanine at a concentration of 100 ppm or more had a reduced lingering aroma. In particular, when the theanine content was 100 ppm or more, the perceived reduction in the lingering aroma of green tea was felt from the middle to the end, resulting in an imbalance between the green aroma and the aroma.

Experiment 2: Production and evaluation of high-theanine green tea beverage
2-1. Production and evaluation of green tea beverage (theanine content: 300 ppm)
To the base green tea beverage used in Experiment 1, L-theanine (manufactured by Taiyo Kagaku) and digalactosyldiacylglycerol (DGDG, manufactured by Avanti, purity 99% or more) were added and completely dissolved so that the theanine and glyceroglycolipid contents in the green tea beverage were the amounts shown in the table below, to produce a packaged green tea beverage. All of the green tea beverages prepared in this experiment had a nonanal content of about 1 ppb and a catechin content of about 400 ppm (pH: about 6.0).

Next, a sensory evaluation was carried out on the obtained green tea beverages by a panel of six experts. Specifically, the lingering aroma of the green tea beverage samples was evaluated on a four-point scale based on the following criteria, with Sample 1-1 receiving 4 points and Sample 1-2 receiving 1 point. In the sensory evaluation, the panelists drank and discussed the reference Samples 1-1 and 1-2, so that each panelist had a common understanding of the reduction in the lingering aroma. The six expert panelists then evaluated each beverage sample, and the average score of each panelist's evaluation was calculated.
4: The lingering aroma is felt to be equal to that of sample 1-1. 3: The lingering aroma is slightly weaker than that of sample 1-1. 2: The lingering aroma is weaker than that of sample 1-1, but the lingering aroma is felt compared to sample 1-2. 1: The lingering aroma is felt to be equal to or greater than that of sample 1-2.

As is clear from the results shown in the table, the lingering aroma, which was reduced by the high concentration of L-theanine, was improved by adding glyceroglycolipids, resulting in a green tea beverage with a good balance of green and fire aromas and a fresh green tea aroma. As for samples 1-4, one panelist evaluated that although the reduction in the lingering aroma had been improved, the taste was sticky and lacking in sharpness.

2-2. Production and evaluation of green tea beverage (theanine content: 1100 ppm)
To the base green tea beverage used in Experiment 1, L-theanine (manufactured by Taiyo Kagaku) and digalactosyldiacylglycerol (DGDG, manufactured by Avanti) were added and completely dissolved so that the theanine and glyceroglycolipid contents in the green tea beverage were the amounts shown in the table below, to produce a packaged green tea beverage. All of the green tea beverages prepared in this experiment had a nonanal content of about 1 ppb and a catechin content of about 400 ppm (pH: about 6.0).

Next, a sensory evaluation was performed on the obtained green tea beverages by a panel of six experts. Specifically, the lingering aroma of the green tea beverage samples was evaluated on a four-point scale based on the following criteria, with Sample 2-1 receiving 4 points and Sample 2-2 receiving 1 point. In the sensory evaluation, the panelists drank and discussed the reference Samples 2-1 and 2-2, so that each panelist had a common understanding of the reduction in the lingering aroma. The six expert panelists then evaluated each beverage sample, and the average score of each panelist's evaluation was calculated.
4: The lingering aroma is felt to be equal to that of sample 2-1. 3: The lingering aroma is slightly weaker than that of sample 2-1. 2: The lingering aroma is weaker than that of sample 2-1, but the lingering aroma is felt compared to sample 2-2. 1: The lingering aroma is felt to be equal to or greater than that of sample 2-2.

As is clear from the results shown in the table, the lingering aroma that was reduced by the high concentration of L-theanine was improved by adding glyceroglycolipids, resulting in a green tea beverage with a good balance of green and fire aromas and a fresh green tea aroma.

2-3. Production and evaluation of green tea beverage (theanine content: 2000 ppm)
To the base green tea beverage used in Experiment 1, L-theanine (manufactured by Taiyo Kagaku) and digalactosyldiacylglycerol (DGDG, manufactured by Avanti) were added and completely dissolved so that the theanine and glyceroglycolipid contents in the green tea beverage were the amounts shown in the table below, to produce a packaged green tea beverage. All of the green tea beverages prepared in this experiment had a nonanal content of about 1 ppb and a catechin content of about 400 ppm (pH: about 6.0).

Next, a sensory evaluation was carried out on the obtained green tea beverages by a panel of six experts. Specifically, the lingering aroma of the green tea beverage samples was evaluated on a four-point scale based on the following criteria, with Sample 3-1 receiving 4 points and Sample 3-2 receiving 1 point. In the sensory evaluation, the panelists drank and discussed the reference Samples 3-1 and 3-2, so that each panelist had a common understanding of the reduction in the lingering aroma. The six expert panelists then evaluated each beverage sample, and the average score of each panelist's evaluation was calculated.
4: The lingering aroma is felt to be equal to that of sample 3-1. 3: The lingering aroma is slightly weaker than that of sample 3-1. 2: The lingering aroma is weaker than that of sample 3-1, but the lingering aroma is felt compared to sample 3-2. 1: The lingering aroma is felt to be equal to or greater than that of sample 3-2.

As is clear from the results shown in the table, the lingering aroma that was reduced by the high concentration of L-theanine was improved by adding glyceroglycolipids, resulting in a green tea beverage with a good balance of green and fire aromas and a fresh green tea aroma.

Experiment 3: Production and evaluation of high-theanine green tea beverage
3-1. Production and evaluation of green tea beverages A base green tea beverage was prepared from a different sencha from that used in Experiment 1 (a sencha tea that was less heated and had a predominantly green aroma compared to the sencha used in Experiment 1). Next, L-theanine (manufactured by Taiyo Kagaku), monogalactosyldiacylglycerol (MGDG, manufactured by Avanti, purity 99% or higher), and digalactosyldiacylglycerol (DGDG, manufactured by Avanti) were added to the base green tea beverage so that the theanine and glyceroglycolipid contents in the green tea beverage were the amounts shown in the table below, and completely dissolved to produce a packaged green tea beverage. All of the green tea beverages prepared in this experiment had a nonanal content of 3.5 ppb and a catechin content of 460 ppm (pH: about 6.0).

Next, a sensory evaluation was carried out on the obtained green tea beverages by a panel of six experts. Specifically, the lingering aroma of the green tea beverage samples was evaluated on a four-point scale based on the following criteria, with sample A-1 receiving 4 points and sample A-2 receiving 1 point. In the sensory evaluation, the panelists drank and discussed the reference samples A-1 and A-2, so that each panelist had a common understanding of the reduction in the lingering aroma, and then the six expert panelists evaluated each beverage sample, and the average score of each panelist's evaluation was calculated.
4: The lingering fragrance is equivalent to that of sample A-1.
3: The aftertaste of the fragrance is slightly weaker than that of sample A-1. 2: The aftertaste of the fragrance is weaker than that of sample A-1, but the aftertaste of the fragrance can be felt compared to sample A-2. 1: The aftertaste of the fragrance is felt to be as weak or weaker than that of sample A-2.

As is clear from the results shown in the table, the lingering aroma, which was reduced by the high concentration of L-theanine, was improved by adding glyceroglycolipids, resulting in a green tea beverage with a good balance of green and fire aromas and a fresh green tea aroma. It was also confirmed that adding monogalactosyldiacylglycerol (MGDG) as the glyceroglycolipid had the same effect as adding digalactosyldiacylglycerol (DGDG).

3-2. Production and Evaluation of Green Tea Beverages A packaged green tea beverage was produced by adding L-theanine (manufactured by Taiyo Kagaku Co., Ltd.) and powdered green tea (first-grade tea) to the base green tea beverage used in Experiment 3-1 so that the theanine and glyceroglycolipid contents in the green tea beverage were the amounts shown in the table below (pH: about 6.0, nonanal content: 5.0 ppb or less).

Next, a sensory evaluation was carried out on the obtained green tea beverages by a panel of six experts. Specifically, the lingering aroma of the green tea beverage samples was evaluated on a four-point scale based on the following criteria, with sample B-1 receiving 4 points and sample B-2 receiving 1 point. In the sensory evaluation, the panelists drank and discussed the reference samples B-1 and B-2, so that each panelist had a common understanding of the reduction in the lingering aroma. The six expert panelists then evaluated each beverage sample, and the average score of each panelist's evaluation was calculated.
4: The lingering fragrance is equivalent to that of sample B-1.
3: The lingering aroma is slightly weaker than that of sample B-1. 2: The lingering aroma is weaker than that of sample B-1, but the lingering aroma can be felt compared to sample B-2. 1: The lingering aroma is reduced to the same extent as or more than that of sample B-2.

As is clear from the results shown in the table, the lingering aroma, which was reduced by the high concentration of L-theanine, was improved by adding glyceroglycolipids, resulting in a green tea beverage with a good balance of green and fire aromas and a fresh green tea aroma. It was also confirmed that the lingering aroma was enhanced when the glyceroglycolipid content in the green tea beverage was adjusted by adding tea powder.

Claims (6)

A packaged green tea beverage having an L-theanine content of 100 to 2200 ppm, a glyceroglycolipid content of 0.2 to 30 ppm, and a nonanal content of 1.0 to 10 ppb. The beverage according to claim 1, wherein the catechin content is 1200 ppm or less. The beverage according to claim 1 or 2, in which the glyceroglycolipid content is 0.8 to 20 ppm. The beverage according to any one of claims 1 to 3, containing green tea powder. The beverage according to any one of claims 1 to 4 , having a nonanal content of 2.0 ppb or more. A method for producing a beverage according to any one of claims 1 to 5 , comprising the steps of:
The above method, which comprises the step of adjusting the L-theanine content to 100 to 2200 ppm and the glyceroglycolipid content to 0.2 to 30 ppm.