Field of the Invention
This invention relates to packaged, tea-based beverages.
Background of the Invention
As effects of catechins, there have been reported a suppressing
effect on the increase of cholesterol and an inhibitory effect on &agr;-amylase
activity (see, for example,
). For such physiological effects to manifest, it is necessary for an adult
to drink tea as much as 4 to 5 cups a day. Accordingly, there has been a great demand
for a technological method by which catechins can be added to beverages at a high
concentration in order to facilitate the ingestion of a large amount of catechins.
As one of the methods for this, catechins are added in a dissolved form to a beverage
by using a green tea concentrate (see, for example,
US-B-6 268 009
discloses green tea extracts subjected to cation exchange treatment and
US-A-5 427 806
discloses green tea extracts having the colour and flavour suitable for
incorporating into non-tea beverage matrixes.
discloses carbonated beverages for strengthening the acid resistancy of
EP-A-0 416 667
discloses beverages containing green tea solids or flavanols.
Where non-polymer catechins are extracted from tea leaves
at high concentration for adding them at high concentration in a beverage, there
is an inevitable drawback that compared with general beverages containing non-polymer
catechins at low concentration, not only the bitterness and astringency derived
from the non-polymer catechins but also the bitterness of caffeine, acridness of
unidentified ingredients and the like synergistically increase, resulting in a beverage
having the flavor and taste which are considerably different from those inherent
Summary of the Invention
The present inventors have, therefore, proceeded with an
investigation to make improvements in flavor and taste while keeping the concentration
of non-polymer catechins high. As a result, it has been found that a packaged, tea-based
beverage reduced in bitterness and acridness and having the inherent flavor and
taste of tea can be obtained by regulating the concentration of non-epicatechins
in the non-polymer catechins, the content ratios of caffeine and total polyphenols
to the non-polymer catechins and the turbidity and pH in predetermined ranges.
In a first aspect of the present invention, there is thus
provided a packaged, tea-based beverage containing the following ingredients (A),
(B) and (C):
- (A) from 320 mg/500 mL to 1,300 mg/500 mL of non-polymer catechins,
- (B) caffeine, and
- (C) water, wherein:
- (D) the content of non-epicatechins in the non-polymer catechins is from 40
to 80 wt.%,
- (E) the weight ratio of the non-polymer catechins to the caffeine is from 5
- (F) the weight ratio of the non-polymer catechins to total polyphenols is from
0.88 to 1.0,
- (G) the turbidity determined by use of a spectrophotometer at wavelength of
660 nm and at 25°C is 0.7 or lower, and
- (H) the pH is from 5 to 7.
The packaged, tea-based beverage according to the present
invention contains non-polymer catechins at high concentration, is reduced in bitterness
and acridness, and is improved in the inherent flavor and taste of tea. Further,
it is low in turbidity, so that it can be distributed in clear packages.
Detailed Description of the Invention
The term "non-polymer catechins" as used herein is a generic
term, which collectively encompasses non-epicatechins such as catechin, gallocatechin,
catechingallate and gallocatechingallate, and epicatechins such as epicatechin,
epigallocatechin, epicatechingallate and epigallocatechingallate.
The packaged, tea-based beverage according to the present
invention contains the non-polymer catechins (A), each of which is a non-polymer
and in a dissolved form in water, at from 320 mg/500 mL to 1, 300 mg/500 mL, preferably
from 320 mg/500 mL to 1,000 mg/500 mL, more preferably from 320 mg/500 mL to 499
mg/500 mL, even more preferably from 360 mg/500 mL to 480 mg/500 mL, still more
preferably from 380 mg/500 mL to 480 mg/500 mL, yet still more preferably from 400
mg/500 mL to 480 mg/500 mL. Insofar as the content of non-polymer catechins falls
within the above-described range, a great deal of non-polymer catechins can be taken
with ease while effectively and sufficiently reducing bitterness and acridness.
The "concentration of non-polymer catechins" as used herein
is defined based on the total amount of eight types of non-polymer catechins consisting
of catechin, gallocatechin, catechingallate, gallocatechingallate, epicatechin,
epigallocatechin, epicatechingallate and epigallocatechingallate, including the
total amount of non-polymer non-epicatechins such as catechin, gallocatechin, catechingallate
In the packaged, tea-based beverage according to the present
invention, the content of the non-epicatechins in the non-polymer catechins is required
to be from 40 to 80 wt.% from the standpoint of effectively improving the long-term
stability, flavor and taste of the packaged, tea-basedbeverage. The content of the
non-epicatechins may be preferably from 46 to 80 wt.%, more preferably from 50 to
80 wt.%, evenmorepreferably from 54 to 80 wt.%. The content of the non-epicatechins
is defined as a weight percentage, which is obtained by dividing the total value
of the concentrations of catechin, gallocatechin, catechingallate and gallocatechingallate
by the total value of the concentrations of the non-polymer catechins.
The weight ratio of the non-polymer catechins to the caffeine
in the packaged, tea-based beverage according to the present invention is from 5
to 8, preferably from 6 to 8, more preferably from 7 to 8 from the standpoint of
effectively reducing bitterness and acridness. If this ratio is smaller than 5,
the bitterness becomes stronger due to the high caffeine content. A ratio greater
than 8 results in stronger astringency.
The weight ratio of the non-polymer catechins to total
polyphenols in the packaged, tea-based beverage according to the present invention
is from 0.88 to 1.0, preferably from 0. 9 to 1.0, more preferably from 0. 92 to
1.0, even more preferably from 0.94 to 1.0, even still more preferably from 0.96
to 1.0. If this ratio is smaller than 0.88, acridness or the like tends to come
The term "total polyphenols" as used herein means ingredients
quantitated by the method that by using ethyl gallate as a standard solution, their
total amount is determined as an amount converted to gallic acid by the ferrous
tartrate method (referential publication: "Green Tea Polyphenols", Technology Series
for the Effective Utilization of Functional Ingredients for Beverages and Foods,
No. 10). In general, non-polymer catechins and their polymers can be detected by
this measurement method.
Further, from 40 to 100 wt.%, preferably from 45 to 100
wt.%, more preferably from 50 to 100 wt.%, even more preferably from 60 to 95 wt.%
of the non-polymer catechins may preferably consist of one or more gallates selected
from epigallocatechingallate, gallocatechingallate, epicatechingallate and catechingallate,
because the balance in flavor and taste between the gallates and caffeine can be
improved further and the inherent flavor and taste of tea can be enjoyed. From the
standpoint of physiological effects, it is also preferred to contain a greater number
From the standpoint of the flavor, taste and external appearance,
the turbidity of the packaged, tea-based beverage according to the present invention
is required to be 0.7 or lower. The turbidity may be preferably 0.5 or lower, more
preferably 0.1 or lower, even more preferably 0.05 or lower, even still more preferably
0.025 or lower. The packaged, tea-based beverage according to the present invention
having a low turbidity as described above can be distributed in clear packages,
especially as a beverage filled in clear PET packages on the market.
From the standpoint of the taste and the chemical stability
of non-polymer catechins, it is preferred to set the pH of the packaged, tea-based
beverage according to the present invention at from 5 to 7 at 25°C.
It is also preferred to control the content of dietary
fibers to from 0.5 to 10 wt.%, preferably from 1 to 7 wt. %, more preferably from
3 to 7 wt. % in the packaged, tea-based beverage according to the present invention
to make improvements in bitterness and acridness. Examples of the dietary fibers
include gum arabic, alginic acid, carageenan, agar, xanthan gum, guar gum, psylium
seed husk gum, gellan gum, gelatin, tamarind seed polysaccharides, tara gum, pharcellulan,
pectin, locust been gum, polydextrose, and carboxymethylcellulose. The dietary fibers
as described herein can be selected from food additives.
The non-polymer catechins for use in the present invention
can be obtained by extraction with water or hot water from tea leaves of green tea
such as sencha (middle-grade green tea), gyokuro (shaded green tea)
or tencha (powdered tea) prepared from green tea leaves available from the
Genus Camellia, for example, C. sinensis, C. assamica, the Yabukita
variety, or a hybrid thereof, semi-fermented tea generally called oolong tea such
as tekkannon (Tieguangin), irotane, ougonkei (Huangjigui) or
buigancha (Wuyiyaucha), or fermented tea (i.e., black tea) such as Darjeeling,
Assam or Sri Lanka.
The extraction of tea can be carried out by a conventional
method such as stirring extraction. An organic acid or organic acid salt, such as
sodium ascorbate, can be added beforehand to water which is to be used for extraction.
It is also possible to make combined use of boiling deaeration or an extraction
method which is conducted while bubbling an inert gas such as nitrogen gas to eliminate
dissolved oxygen, that is, under a so-called non-oxidizing atmosphere.
As a method for adjusting the weight ratio of the non-polymer
catechins to total polyphenols in the packaged, tea-based beverage according to
the present invention, a concentrate of a tea extract may be used in a dissolved
form in water, or a tea beverage, which is commonly consumed, and a concentrate
of a tea extract may be used in combination. As a medium useful for dissolving the
concentrate of the tea extract, water, carbonated water, a tea extract containing
non-polymer catechins at a commercial level, can be mentioned. The term "the concentrate
of a tea extract" as used herein means one obtained by concentrating an extract
of tea leaves in hot water or a water-soluble organic solvent, and as its forms,
various forms can be mentioned such as a solid, aqueous solution and slurry. On
the other hand, the term "tea extract" as used herein include those prepared by
processes exemplified in detail in
, and as commercial products, "POLYPHENON™" (product
of Mitsui Norin Co., Ltd.), "TEAFURAN™" (product of ITO EN, LTD.),
"SUNPHENON™" (product of Taiyo Kagaku Co., Ltd.), "SUN OOLONG™"
(product of Suntory Limited) can be mentioned. In addition, catechins originated
from other raw materials, column-purified catechins and chemically synthesized catechins
can also be used. As the tea extract or the concentrate of the tea extract, it is
preferred from the viewpoint of a taste to use one having a non-polymer catechin
concentration of 40 wt.% or higher, preferably from 40 to 90 wt.%, more preferably
from 50 to 90 wt.%, especially from 50 to 85 wt.% based on its solid content.
Non-epicatechins can be obtained by preparing an aqueous
solution of an extract of green tea, semi-fermented tea, fermented tea or a concentrate
of such a tea extract and subjecting the resultant solution to heat treatment, for
example, at from 40 to 140°C for from 0.1 minute to 120 hours. From the ease
in forming non-epicatechins, it is preferred to adjust the pH of the solution to
5 or higher in the consideration of the easiness of purification of non-epicatechins.
As an alternative, a concentrate of a tea extract having a high non-epicatechin
content can be used. They can be used either singly or in combination. By such treatment
or procedure, the content of non-epicatechins can be controlled.
To control the non-polymer catechins/caffeine weight ratio
to from 5 to 8, it is possible to employ a procedure making use of the method that
a tea extract, a concentrate of a tea extract or a mixture thereof is brought into
contact with a caffeine absorbent (
), the method that a tea extract, a concentrate of a tea extract or a mixture
thereof is brought into contact with activated clay or acid clay (
). In particular, to allow the composition of non-polymer catechins to
remain unchanged, the method that a concentrate of a green tea extract is dissolved
in a 9/1 to 1/9 mixed solution of ethanol and water by weight ratio and the solution
is brought into contact with activated carbon and acid clay or activated clay is
An adjustment of the turbidity, on the other hand, can
be effected by using methods such as diatomaceous earth filtration, centrifugal
separation, microfiltration, ultrafiltration and creaming down, either singly or
The packaged, tea-based beverage according to the present
invention contains water, and the amount of water in the beverage is preferably
not less than 80 wt. %, more preferably not less than 85 wt.%, still more preferably
not less than 90 wt.%, even more preferably from 90 to 99.9 wt.%, and particularly
preferably from 95 to 99.9 wt.%.
Examples of the packaged, tea-based beverage according
to the present invention include green tea beverages, semi-fermented tea beverages
and fermented tea beverages, within which green-tea-based beverages are more preferred.
To the packaged, tea-based beverage according to the present
invention, it is possible to add, in combination with the ingredients derived from
tea, additives - such as antioxidants, flavorants, various esters, organic acids,
organic acid salts, inorganic acids, inorganic acid salts, inorganic salts, colorants,
emulsifiers, preservatives, seasoning agents, sweeteners, sour seasonings, fruit
extracts, vegetable extracts, flower honey extracts, pH regulators and quality stabilizers
- either singly or in combination to adjust its flavor, taste and/or quality.
Examples of the sweeteners include sugar, glucose, fructose,
isomerized syrup, glycyrrhizin, stevia, aspartame, fructooligosaccharide, galactooligosaccharide,
and other oligosaccharides such as cyclodextrins. Usable examples of the cyclodextrins
include &agr;-, &bgr;- and &ggr;-cyclodextrins and branched &agr;-, &bgr;-
and &ggr;-cyclodextrins. In addition, artificial sweeteners can also be used.
Examples of the sour seasonings include, in addition to
fruit juices and the like extracted from natural sources, citric acid, tartaric
acid, malic acid, lactic acid, fumaric acid, and phosphoric acid.
Examples of the inorganic acids and inorganic acid salts
include phosphoric acid, disodium phosphate, sodium metaphosphate, and sodium polyphosphate.
Examples of the organic acids and organic acid salts include citric acid, succinic
acid, itaconic acid, malic acid, and sodium citrate.
Similar to general beverages, a package useful for the
packaged, tea-based beverage according to the present invention can be provided
in an ordinary form such as a molded package made of polyethylene terephthalate
as a principal component (a so-called PET bottle), a metal can, a paper container
combined with metal foils or plastic films, or a bottle. Among such packaged, tea-based
beverages, a beverage filled in a clear PET package is preferred.
The packaged, tea-based beverage according to the present
invention can be produced, for example, by filling the tea beverage in a container
such as a metal can and, when heat sterilization is feasible, conducting heat sterilization
under sterilization conditions as prescribed in the Food Sanitation Act. For those
which cannot be subjected to retort sterilization like PET bottles or paper containers,
a process is adopted such that the tea beverage is sterilized beforehand under similar
sterilization conditions as those described above, for example, by a plate-type
heat exchanger, is cooled to a particular temperature, and is then filed in a container.
Under aseptic conditions, additional ingredients may be added to and filled in a
filled container. It is also possible to conduct an operation such that subsequent
to heat sterilization under acidic conditions, the pH of the tea beverage is restored
to neutral under aseptic conditions or that subsequent to heat sterilization under
neutral conditions, the pH of the tea beverage is restored to the acidic side under
The following examples further describe and demonstrate
embodiments of the present invention. The examples are given solely for the purpose
Measurement of non-polymer catechins
A high-performance liquid chromatograph (model: SCL-10AVP)
manufactured by Shimadzu Corporation was used. The chromatograph was fitted with
an LC column packed with octadecyl-introduced silica gel, "L-Column, TM ODS" (4.
6 mm in diameter x 250 mm in length; product of Chemicals Evaluation and Research
Institute, Japan). A beverage, which had been filtrated through a filter (0.8 µm),
was subjected to chromatography at a column temperature of 35°C by gradient
elution. A 0.1 mol/L solution of acetic acid in distilled water and a 0.1 mol/L
solution of acetic acid in acetonitrile were used as mobilephase solutionAandmobilephase
solution B, respectively. The measurement was conducted under the conditions of
10 µL injected sample quantity and 280 nm UV detector wavelength.
Measurement of turbidity
Using a spectrophotometer (Model: U-2010) manufactured
by Hitachi, Ltd., each packaged beverage was placed in a glass cell and measured
at 25°C. The measurement wavelength of the spectrophotometer at the time of
the analysis was set at 660 nm.
Measurement of total polyphenols
Using ethyl gallate as a standard solution, total polyphenols
were determined as an amount converted to gallic acid by the ferrous tartrate method
(referential publication: "Green Tea Polyphenols", Technology Series for the Effective
Utilization of Functional Ingredients for Beverages and Foods, No. 10). Specifically,
a sample (5 mL) was stained with the standard ferrous tartrate solution (5 mL).
With a phosphate buffer, the volume of the thus-stained sample was adjusted to 25
mL. Its absorbance was measured at 540 nm, and from a calibration line for ethyl
gallate, the total polyphenols were determined.
Preparation of the standard ferrous tartrate solution:
Ferrous sulfate heptahydrate (100 mg) and potassium sodium tartrate (Rochelle salt,
500 mg) were dissolved with distilled water to 100 mL.
Preparation of the phosphate buffer: A 1/15 M solution
of disodium hydrogenphosphate and a 1/15 M solution of sodium dihydrogenphosphate
were mixed to give pH of 7.5.
Measurement of caffeine amount
A high-performance liquid chromatograph (manufactured by
Hitachi, Ltd.) was used.
- Plotter: "D-2500", Detector: "L-4200", Pump: "L-7100",
- Autosampler: "L-7200", Column: "Intersil ODS-2" (2.1 mm inner diameter ×
250 mm length).
(Retention time of caffeine)
Injected sample quantity: 10 µL
Flow rate: 0.3 mL/min
Detection wavelength of UV spectrophotometer: 280 nm
Eluent A: 0.1 M solution of acetic acid in water
Eluent B: 0.1 M solution of acetic acid in acetonitrile
Conditions of concentration gradient (vol. %)
From each area % determined here, the corresponding wt.%
was determined based on the standard substance.
1) Production of a purified solution of a green tea extract
A green tea extract concentrate ("POLYPHENON™
HG", product of Tokyo Food Techno Co., Ltd.) had a non-polymer catechin content
of 33.70 wt.%, a caffeine content of 5.5 wt.%, a non-polymer catechins/caffeine
ratio of 6.1, and a gallates content of 50.7 wt.%, and the pH of its water-diluted
solution (Brix 20) was 4.7. "POLYPHENON™ HG" (100 g, product of
Tokyo Food Techno Co., Ltd.) was suspended in a 95% aqueous solution of ethanol
(490.9g) under stirring at 250 rpmat room temperature. After activated carbon "KURARAY
COAL™ GLC" (10 g, product of Kuraray Chemical K.K.) and acid clay
"MIZKA ACE™ #600" (20 g, product of Mizusawa Chemical Industries,
Ltd.) were poured, the resulting mixture was continuously stirred for about 10 minutes.
Subsequent to the dropwise addition of a 40% aqueous solution of ethanol (409.1
g) over 10 minutes, stirring was continued for about 30 minutes at room temperature.
After the activated carbon and a precipitate were filtered off by No. 2 filter paper,
the filtrate was filtered again through a 0.2 µm membrane filter. Finally,
deionized water (200 g) was added to the filtrate, ethanol was distilled off at
40°C under 3.33 kPa, and then, the Brix was adjusted with deionized water to
24.1 to obtain a purified solution.
The thus-obtained purified solution had the following composition:
the concentration of non-polymer catechins: 10%, caffeine: 0.9%, total polyphenols:
11.9%, and gallates content: 54%.
2) Production of a green tea extract
A fourth tea harvest from Nara of green tea leaves was
extracted at a bath ratio of 30 at 65°C for 5 minutes. Subsequent to filtration
through a 20-mesh screen, the filtrate was filtered through an 80-mesh screen and
finally through a zeta membrane. The thus-obtained green tea extract had the following
composition: the concentration of non-polymer catechins: 0.2%, caffeine: 0.056%,
total polyphenols: 0.208%, and gallates content: 48%.
Examples 1-2 & Comparative Examples 1-5
Each green tea beverage filled in clear PET packages was
prepared by combining the ingredients in accordance with the formulation in table
1, adjusting the pH of the resultant mixture to 6, sterilizing the mixture at 137°C
for 30 seconds, and then filling the thus-sterilized mixture in 500-mL PET packages.
After stored at 40°C for 1 week, the beverage obtained
as described above was ranked in flavor and taste by 10 expert panelists in accordance
with the below-described raking standards. The results are shown in Table 1.
- 3: Deliciousness, bitterness and astringency are well balanced.
- 2: Average.
- 1: Deliciousness, bitterness and astringency are poorly balanced.
Comp. Ex. 1
Comp. Ex. 2
Comp. Ex. 3
Comp. Ex. 4
Comp. Ex. 5
Purified solution of green tea extract1)
Green tea extract2)
Sodium ascorbate 3)
Heat treatment (137°C, 30 sec)
Analytical data after
Conc'n of non-polymer catechins
Conc'n of caffeine
Conc'n of total polyphenols
Cont. of non-epicatechins
Non-polymer catechins/total polyphenols
Turbidity (660 nm)
Ranking results of flavor and taste
(after storage at 40°C for 1 week)
1 (with acrid and coarse tastes)
1 (w/o delici ousnes s)
1 (with coarse taste)
2 (with coarse taste)
1) Purified product of "POLYPHENON
HG" (product of Tokyo Food Techno Ltd.),
2) Extract of a fourth tea harvest from Nara,
3) Daiichi Fine Chemical Co., Ltd.,
4) NIHON SHOKUHIN KAKO CO., LTD.,
5) TOSOH CORPORATION,
6) T. HASEGAWA CO., LTD.,
7) Brand name ("OSUSHIYASAN NO OCHA")
As evident from Table 1, the packaged green tea beverage
of Comparative Example 1 in which the non-polymer catechins/caffeine ratio was small
and the packaged green tea beverage of Comparative Example 2 in which the non-polymer
catechins/total polyphenols ratio was small had acrid and coarse tastes and failed
to provide the inherent flavor and taste of tea. Further, the packaged green tea
beverages of Comparative Examples 4 and 5 in each of which the non-polymer catechins/total
polyphenols ratio was small had a coarse taste. In contrast, the packaged green
tea beverages of Examples 1 and 2 had a good flavor and taste even after the long-term
storage although they contained non-polymer catechins at high concentration.
Moreover, no changes were observed on the external appearances of the packaged green
tea beverages of Examples 1 and 2.