U.S. patent application number 11/016863 was filed with the patent office on 2005-07-28 for production process of packaged green tea beverages.
This patent application is currently assigned to Kao Corporation. Invention is credited to Hanaoka, Koji, Matsui, Yuji, Mizuno, Wataru, Otsuka, Kazuhiro, Takatsu, Hideyuki.
Application Number | 20050163890 11/016863 |
Document ID | / |
Family ID | 32829080 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050163890 |
Kind Code |
A1 |
Otsuka, Kazuhiro ; et
al. |
July 28, 2005 |
Production process of packaged green tea beverages
Abstract
A process is disclosed for the production of a packaged green
tea beverage containing non-polymer catechins at a concentration of
0.05 to 0.5 wt. %. According to the process, an aluminosilicate
which has an iron release rate of not greater than 0.8 mg/kg to a
catechin-containing solution is brought into contact with a green
tea mixture of a green tea extract and a concentrate of green tea
extract. The present invention can provide beverages, which contain
catechins at high concentration and inhibit the formation of dregs
during long-term storage.
Inventors: |
Otsuka, Kazuhiro; (Tokyo,
JP) ; Mizuno, Wataru; (Tokyo, JP) ; Hanaoka,
Koji; (Tokyo, JP) ; Matsui, Yuji; (Tokyo,
JP) ; Takatsu, Hideyuki; (Tokyo, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Kao Corporation
Tokyo
JP
|
Family ID: |
32829080 |
Appl. No.: |
11/016863 |
Filed: |
December 21, 2004 |
Current U.S.
Class: |
426/106 |
Current CPC
Class: |
A23F 3/163 20130101 |
Class at
Publication: |
426/106 |
International
Class: |
C12C 001/027 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2003 |
JP |
2003-424556 |
Mar 9, 2004 |
JP |
2004-065110 |
Claims
What is claimed is:
1. A packaged green tea beverage with a concentrate of a green tea
extract mixed therein, comprising: (a) 0.05 to 0.5 wt. % of
non-polymer catechins in which the weight ratio [(A)/(B)] of (A)
non-epicatechins to (B) epicatechins is from 0.54 to 9.0; (b) 10 to
30 mg/kg of aluminum ions; and (c) 10 to 30 mg/kg of silicon
ions.
2. A process for the production of a packaged green tea beverage
containing non-polymer catechins at a concentration of 0.05 to 0.5
wt. %, which comprises bringing an aluminosilicate, which has an
iron release rate of not greater than 0.8 mg/kg to a
catechin-containing solution, into contact with a green tea mixture
of a green tea extract and a concentrate of green tea extract.
3. The process for the production of a packaged green tea beverage
according to claim 2, wherein the aluminosilicate is added in the
proportion of 0.05 to 0.5 wt % based on the green tea mixture.
4. The process for production of a packaged green tea beverage
according to claim 2, wherein the packaged green tea beverage is
the packaged green tea beverage according to claim 1.
5. The process for the production of a packaged green tea beverage
according to claim 3, wherein the packaged green tea beverage is
the packaged green tea beverage according to claim 1.
Description
FIELD OF THE INVENTION
[0001] This invention relates to packaged green tea beverages and
their production process.
BACKGROUND OF THE INVENTION
[0002] As effects of catechins, there have been reported an
inhibitory effect on .alpha.-amylase activity and the like (see,
for example, JP-A-03-133928). To such a physiological effect to
manifest, it is necessary for an adult to drink tea as much as 4 to
5 cups in a day. Accordingly, there has been a demand for a
technology that enables the addition of catechins at high
concentration in beverages to facilitate the ingestion of a large
amount of catechins. As one of methods for this, catechins are
added in a dissolved form to a beverage by using a green tea
extract (see, for example, JP-A-59-219384).
[0003] Packaged beverages of green tea are accompanied by the
problem of dregs caused by high molecular components such as pectin
and hemicellulose during long-term storage, and a variety of
methods have been reported for its resolution, including the use of
an ultrafiltration membrane (see, for example, JP-A-4-45744).
[0004] Treatment methods using various adsorbents, without using
any ultrafiltration membrane, have also been attempted (see, for
example, JP-A-62-278948 and JP-A-57-29250).
[0005] Concerning the technology on the application of zeolite to
tea leaves, on the other hand, the addition of zeolite to green tea
leaves or to a substance derived from green tea leaves has been
studied (see, for example, Published Japanese Translation No.
2000-508916 of PCT International Application)
SUMMARY OF THE INVENTION
[0006] In one aspect of the present invention, there is provided a
packaged green tea beverage with a concentrate of green tea extract
mixed therein. The packaged green tea beverage contains:
[0007] (a) 0.05 to 0.5 wt. % of non-polymer catechins in which the
weight ratio [(A)/(B)] of (A) non-epicatechins to (B) epicatechins
is 0.54 to 9.0;
[0008] (b) 10 to 30 mg/kg of aluminum ions; and
[0009] (c) 10 to 30 mg/kg of silicon ions.
[0010] In another aspect of the present invention, there is also
provided a process for the production of a packaged green tea
beverage containing non-polymer catechins at a concentration of
from 0.05 to 0.5 wt. %. The process contains bringing an
aluminosilicate, which has an iron release rate of not greater than
0.8 mg/kg to a catechin-containing solution, into contact with a
green tea mixture of a green tea extract and a concentrate of green
tea extract.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The conventional method that removes high molecular
components from a green tea extract by filtering the green tea
extract through an ultrafiltration membrane is accompanied by the
drawback that refined taste components of tea are adsorbed on a
filter aid and the flavor and taste characteristic of tea are
reduced, although the formation of dregs can be avoided.
[0012] The treatment methods, which rely upon various adsorbents
without using an ultrafiltration membrane, can be divided into two
groups depending upon the adsorbents. The treatment methods in one
of the groups (see, for example, JP-62-298948 referred to in the
above) eliminate tannin (non-polymer catechins), which is a
physiologically-effective component, with silica gel from a tea
extract by taking it as a causative substance of a color change and
turbidness, and therefore these methods cannot be applied to
beverages to be provided for the ingestion of a great deal of
catechins.
[0013] The treatment methods in the other group (see, for example,
JP-57-29250 referred to in the above) make use of a polyamide or
the like to lower the content of causative substances of a color
change, placing an importance on the prevention of a color change.
JP-57-29250 and the like, however, make no mention about a
preventive effect for dregs. Further, zeolite and acid clay are not
suited for application because they lack practical utility.
[0014] The technology on the application of zeolite to tea leaves
is intended to assure the development of an attractive red color
upon production of black tea leaves from green tea leaves, and
Published Japanese Translation No. 2000-508916 of PCT International
Application referred to the above does not even make a reference to
the prevention of dregs in green tea beverages.
[0015] An object of the present invention is to provide a packaged
green tea beverage which contains catechins at high concentration
and inhibits the formation of dregs during long-term storage, and
also its production process.
[0016] The present inventors have proceeded with an investigation
to inhibit the formation of dregs in a packaged green tea beverage
containing catechins at high concentration, during long-term
storage. As a result, it has been found that the formation of dregs
in a packaged green tea beverage containing non-polymer catechins
at high concentration during long-term storage can be inhibited by
bringing a specific aluminosilicate into contact with a green tea
mixture of a green tea extract and a concentrate of green tea
extract.
[0017] 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.
[0018] Examples of green tea leaves for use in the present
invention include tea leaves prepared from green tea leaves of the
Genus Camellia, for example, C. sinensis, C. assamica and the
Yabukita variety, or their hybrids. No particular limitation is
imposed on the prepared tea leaves insofar as they are
non-fermented tea. Preferred examples of steamed tea leaves include
sencha (middle-grade green tea), fukamushicha (deep-steamed green
tea), gyokuro (shaded green tea), kabusecha (partially shaded green
tea), mushi-tamaryokucha (steamed, rounded, beads-shaped green
tea), and bancha (coarse green tea). Preferred examples of roasted
tea leaves, on the other hand, include kamairi-tamaryokucha
(roasted, rounded, beads-shaped green tea) and Chinese green
tea.
[0019] The green tea extract for use in the present invention can
be produced under ordinary extraction conditions. Upon extraction
from green tea leaves, the temperature can be altered as needed
depending upon the tea leaves to be extracted. In the cases of
sencha and mushi-tamaryokucha, for example, temperature of from 60
to 90.degree. C. is preferred. In the cases of gyokuro and
kabusecha, temperature of from 50 to 60.degree. C. is preferred. In
the case of bancha, on the other hand, no problem arises even at a
temperature of from 90.degree. C. to the boiling temperature. Upon
extraction from green tea leaves, the amount of water can be
preferably from 5 to 60 times by weight, more preferably from 5 to
40 times by weight of the green tea leaves. The extraction time
from green tea leaves is preferably from 1 to 60 minutes, more
preferably from 1 to 40 minutes, even more preferably from 1 to 30
minutes. For example, an extract can be obtained from middle-grade
green tea leaves by adding the tea leaves into deionized water
heated to 65.degree. C., stirring for 2 minutes or so, allowing
them to stand still for 2 minutes or so, removing the tea leaves
with a filter, and then removing fine tea leaves with a flannel
filter cloth.
[0020] As the concentrate of green tea extract for use in the
present invention, one obtained by concentrating an extract of
green tea leaves in hot water or a water-soluble organic solvent
can be mentioned. Examples include those prepared by processes
exemplified in detail in JP-A-59-219384, JP-A-4-20589,
JP-A-5-260907, JP-A-5-306279, JP-A-2003-219800 and
JP-A-2003-304811, respectively. As commercial products,
"POLYPHENON.TM." (product of Mitsui Norin Co., Ltd.),
"TEAFURAN.TM." (product of ITO EN, LTD.), "SUNPHENON.TM." (product
of Taiyo Kagaku Co., Ltd.) and the like can be mentioned. In
addition, column-purified products and chemically synthesized
products can also be used. As forms of a "concentrate of green tea
extract" used herein various forms can be mentioned such as a
solid, an aqueous solution and slurry.
[0021] The green tea mixture for use in the present invention can
be obtained, for example, by mixing a green tea extract from green
tea leaves with a concentrate of green tea extract such that the
absolute amount of substances in a packaged green tea
beverage--said substances are presumed to take part in the
formation of dregs with time and including pectin and hemicellulose
as causative substances of dregs--can be minimized while raising
the concentration of non-polymer catechins as an effective
ingredient in the beverage. Here, the mixing ratio of the green tea
extract to the concentrate of green tea extract can be adjusted
based on the solid concentration of the green tea extract and the
concentration of non-polymer catechins in the concentrate of green
tea extract such that the concentration of non-polymer catechins in
the packaged green tea beverage to be obtained finally falls within
the range of from 0.05 to 0.5 wt. %.
[0022] The packaged green tea beverage according to the present
invention contains non-polymer catechins in a water-dissolved form
at a concentration of from 0.05 to 0.5 wt. %, preferably from 0.06
to 0.5 wt. %, more preferably from 0.07 to 0.5 wt. %, even more
preferably from 0.08 to 0.5 wt. %, even more preferably from 0.092
to 0.5 wt. %, even more preferably from 0.1 to 0.4 wt. %. From the
standpoint of physiological effects, non-polymer catechins can be
contained in a water-dissolved form at a concentration of
preferably from 0.11 to 0.3 wt. %, more preferably from 0.12 to 0.3
wt. %. A concentration of non-polymer catechins lower than 0.05 wt.
% makes it difficult to easily ingest a great deal of catechins at
once. A concentration of non-polymer catechins higher than 0.5 wt.
%, on the other hand, makes it impossible to make improvements in
bitterness and astringency.
[0023] The concentration of non-polymer catechins in the present
invention 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.
[0024] The weight ratio (A/B) of the non-epicatechins (A) to the
epicatechins (B) in the packaged green tea beverage according to
the present invention may preferably be from 0.54 to 9.0, more
preferably from 0.55 to 9.0, even more preferably from 0.67 to 9.0,
and even more preferably from 1.0 to 9.0 from the standpoint of
controlling a hue change during storage.
[0025] For the non-polymer catechins in the packaged green tea
beverage according to the present invention, it is preferred that
the ratio of total gallocatechins as a generic term, which consist
of epigallocatechingallate, gallocatechingallate, epigallocatechin
and gallocatechin, to total non-gallocatechins as a generic term,
which consist of epicatechingallate, catechingallate, epicatechin
and catechin, retain the corresponding ratio in natural green tea
leaves.
[0026] The percentage of gallates as a generic term, which consist
of catechingallate, epicatechingallate, gallocatechingallate and
epigallocatechingallate, in the non-polymer catechins in the
packaged green tea beverage according to the present invention is
preferably 45 wt. % or greater from the standpoint of the
effectiveness of physiological action of the non-polymer
catechins.
[0027] The concentration of aluminum ions in the packaged green tea
beverage according to the present invention is from 10 to 30 mg/kg,
preferably from 15 to 30 mg/kg, more preferably from 20 to 30
mg/kg. A concentration of aluminum ions lower than 10 mg/kg is not
preferred because dregs tend to occur prematurely during storage.
Such an excessively low concentration is not suited for the
packaged green tea beverage according to the present invention.
[0028] The concentration of silicon ions in the packaged green tea
beverage according to the present invention is from 10 to 30 mg/kg,
because this concentration range of silicon ions keeps the green
tea beverage free from the occurrence of dregs for an extended
period of time during its storage. A preferred range is from 15 to
35 mg/kg, with the range of from 20 to 30 mg/kg being more
preferred.
[0029] Aluminum ions and silicon ions may be incorporated in the
packaged green tea beverage according to the present invention, for
example, by contact-treating the above-described green tea mixture
with an aluminosilicate. As aluminosilicates, acid clay, activated
clay, zeolite and the like can be mentioned. It was found that the
formation of dregs during long-term storage of a packaged green tea
beverage could be inhibited for the first time when an
aluminosilicate having an iron release rate of not greater than 0.8
mg/kg to a catechin-containing solution was selectively used.
Described specifically, the above-described green tea mixture was
treated with various aluminosilicates. The use of an
aluminosilicate whose release rate was higher than 0.8 mg/kg led to
an increase in the content of iron in the green tea mixture, and as
a result, the green tea mixture turned into a dark green color.
Elution of iron metal from an aluminosilicate does not generally
take place in a water dispersion system but it does in a dispersion
system of green tea mixture. Unless an aluminosilicate preferably
having an iron release rate of not greater than 0.8 mg/kg to a
catechin-containing solution is used, coloration takes place, and
moreover, long-term storage stability cannot be assured for the
resulting packaged green tea beverage.
[0030] The release rate of iron from an aluminosilicate into a
catechin-containing solution can be measured, for example, by a
model system to be described next. Specifically, adding 0.15 wt. %
of an aluminosilicate to a model green tea extract in which the
concentration of non-polymer catechins is from 0.17 to 0.19 wt. %,
the percentage of gallocatechins in all the non-polymer catechins
is from 46 to 57 wt. % and the pH is within 6.0 .+-.0.4; to
subjecting the model green tea extract to adsorption treatment; and
then measuring the content of iron in the thus-treated green tea
extract. More specifically, 0.15 wt. % of an aluminosilicate (for
example, activated clay or zeolite) which is in a dry state is
added to the above-described model green tea extract. The resulting
mixture is stirred at room temperature for 10 minutes, followed by
the filtration through a 0.8-.mu.m membrane filter. The
thus-obtained green tea extract is filled in a heat-resistant glass
container. After the head space of the container is purged with
nitrogen gas, the container is sealed and subjected to
sterilization at 121.degree. C. for 10 minutes in an autoclave.
Subsequent to the completion of the sterilization, the green tea
extract is immediately chilled to 30.degree. C. or lower, and the
content of iron in the green tea extract is measured. By such a
measuring method, an aluminosilicate whose iron release rate is
preferably 0.8 mg/kg or lower can be selected with ease which may
hereinafter be referred to as the "specific aluminosilicate".
[0031] Examples of the specific aluminosilicate usable in the
present invention include activated clay, acid clay, and zeolite.
Preferred examples of activated clay include "GALLEON EARTH.TM.NV",
"GALLEON EARTH.TM.NS" and "GALLEON EARTH.TM.V1", all of which are
products of Mizusawa Chemical Industries, Ltd. Usable examples of
zeolite include not only natural zeolites but also synthetic
zeolites. Specifically, zeolite P and zeolite 4A are preferred.
[0032] Upon contact-treatment of the above-described green tea
mixture with the specific aluminosilicate in the present invention,
the concentration of the specific aluminosilicate can be preferably
from 0.05 to 0.5 wt. %, more preferably from 0.1 to 0.5 wt. %, even
more preferably from 0.15 to 0.4 wt. % based on the green tea
mixture from the standpoint of the preventive effect for dregs and
efficiency.
[0033] The contact-treatment temperature of the above-described
green tea mixture with the specific aluminosilicate is preferably
from 0 to 80.degree. C., more preferably from 10 to 50.degree. C.
from the standpoint of obviating the need for cooling facilities
and avoiding any potential deterioration of the green tea
mixture.
[0034] The contact-treatment time of the above-described green tea
mixture with the specific aluminosilicate may be preferably from 5
to 120 minutes, more preferably from 5 to 60 minutes from the
standpoint of the effect and efficiency of adsorption.
[0035] The successful inhibition of dregs during long-term storage
by the contact-treatment of the green tea mixture with the specific
aluminosilicate is considered to be attributable, but not limited,
to the adsorption of dreg-forming substances to the specific
aluminosilicate. In other words, the contact-treatment of the green
tea mixture with the specific aluminosilicate is, therefore,
considered to be equivalent to an adsorption-treatment with the
specific aluminosilicate.
[0036] After the specific aluminosilicate is added and the green
tea mixture is contact-treated with the specific aluminosilicate,
the aluminosilicate is removed by filtration.
[0037] As a filtration method for use in the present invention, a
general method, for example, any one of gravity, pressure and
vacuum filtration methods can be used. Upon conducting the
filtration, the temperature can be similar to the temperature of
contact-treatment of the green tea mixture from the standpoint of
the working efficiency. A filter aid may be used as desired to
increase the filtration rate. It is also possible to prepare a
column packaged with the specific aluminosilicate, allowing the
green tea mixture to flow through the column. In this case, no
filtration step is required specifically so a labor-saving is
feasible.
[0038] From the standpoint of providing the non-polymer catechins
with chemical stability and facilitating the inhibition of dreg
formation during long-term storage, the pH of the packaged green
tea beverage according to the present invention is controlled to
preferably from 5.0 to 7.0, more preferably from 5.5 to 7.0, even
more preferably from 5.6 to 6.4, even more preferably from 6.1 to
6.4 at 25.degree. C.
[0039] A bitterness suppressor may be added to the packaged green
tea beverage according to the present invention to make it
palatable. No particular limitation is imposed on the bitterness
suppressor, but a cyclodextrin is preferred. As a cyclodextrin, an
.alpha.-, .beta.- or .gamma.-cyclodextrin or a branched .alpha.-,
.beta.- or .gamma.-cyclodextrin can be used. In the packaged green
tea beverage according to the present invention, the cyclodextrin
can be contained at a concentration of preferably from 0.01 to 0.5
wt. %, more preferably from 0.01 to 0.3 wt. %.
[0040] To the packaged green tea 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, pH regulators and
quality stabilizers--either singly or in combination. Examples of
the inorganic acids and inorganic acid salts include phosphoric
acid, disodium phosphate, sodium metaphosphate, and sodium
polyphosphate. These inorganic acids and inorganic acid salts may
be contained preferably at a concentration of from 0.01 to 0.5 wt.
%, with from 0.01 to 0.3 wt. % being more preferred, in the
packaged green tea beverage according to the present invention.
[0041] Similar to general beverages, a molded package made of
polyethylene terephthalate as a principal component (so-called PET
bottle), a metal can, a paper package combined with metal foils or
plastic films, or a bottle can be used as a package for the
production of the packaged beverage according to the present
invention. The term "packaged beverage" as used herein means a
beverage which can be taken without dilution.
[0042] The packaged green tea beverage according to the present
invention can be produced, for example, by filling the beverage in
a package 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 packages, a process is adopted such that the beverage is
sterilized beforehand under similar sterilization conditions as
those described above, for example, at a high temperature for a
short time by a plate-type heat exchanger, is cooled to a
predetermined temperature, and is then filled in a package. Under
aseptic conditions, additional ingredients maybe added to and
filled in a filled package.
[0043] The following examples further describe and demonstrate
embodiments of the present invention. The examples are given solely
for the purpose of illustration and are not to be construed as
limitations of the present invention.
EXAMPLES
[0044] <Measurement of Catechins>
[0045] 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.times.250 mm in
length; product of Chemicals Evaluation and Research Institute,
Japan). A packaged beverage, which had been filtered through a
filter (0.8 .mu.m) and then diluted with distilled water, was
subjected to chromatography at a column temperature of 35.degree.
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 mobile phase solution A and mobile phase
solution B, respectively. The measurement was conducted under the
conditions of 20 .mu.L injected sample quantity and 280 nm UV
detector wavelength.
[0046] <Measurements of Iron Content, Silicon Ion Concentration
and Aluminum Ion Concentration>
[0047] Concerning the Fe concentration, silicon ion concentration
and aluminum ion concentration in each sample to be ranked,
quantitation was conducted by CIP analysis.
[0048] (System)
[0049] ICP emission spectrometer, "SPS 3000" (manufactured by Seiko
Instruments, Inc.)
[0050] (Measurement conditions for inductively coupled plasma
emission spectrometry)
[0051] High frequency output: 1.2 KW
[0052] Reflected wave input: >2 W
[0053] Plasma gas flow rate: 18 L/min
[0054] Carrier gas pressure: 2 kgf/cm.sup.2
[0055] Auxiliary gas flow rate: 1.2 L/min
[0056] Chamber gas flow rate: 0.6 L/min
[0057] Measurement height: 12 mm above an L/R spectroscope
[0058] Measurement wavelength: A1 (396.152 nm)
[0059] Torch: water-based
[0060] Nebulizer: water-based
[0061] Chamber: Scott type
[0062] (Fe, Si and Al standard solutions)
[0063] Fe (1000 mg/L) standard solution for atomic absorption
spectroscopy (product of Wako Pure Chemical Industries, Ltd.)
[0064] Si (1000 mg/L) standard solution for atomic absorption
spectroscopy (product of Wako Pure Chemical Industries, Ltd.)
[0065] Al (1000 mg/L) standard solution for atomic absorption
spectroscopy (product of Wako Pure Chemical Industries, Ltd.)
[0066] <Measurement of Lightness>
[0067] Color difference meter, "ZE 2000" (manufactured by Nippon
Denshoku Industries Co., Ltd.)
[0068] Zero-adjustment black plate, "0-ADJ" (manufactured by Nippon
Denshoku Industries Co., Ltd.)
[0069] The power was turned on. After the color difference meter
was left for 15 minutes, "0-ADJ" was inserted in a measurement
unit, and calibration was performed relative to a standard.
Subsequently, a glass cell was filled to an index mark with a
sample. The glass cell was inserted in the measurement unit to
perform a measurement. In a color specification system displayed
after the measurement, the L-value was used.
[0070] <Ranking Method of Dregs>
[0071] Each sample to be tested, which was contained in a clear
container, was observed for the condition of its content on an
illuminator. The day on which dregs were observed for the first
time was determined as an occurrence day of dregs.
[0072] Test 1
[0073] Testing Method
[0074] (Preparation of Green Tea Mixture)
[0075] A concentrate of green tea extract ["POLYPHENON.TM."
(product of Mitsui Norin Co., Ltd.; content of non-polymer
catechins: 33.70 wt. %)] was added to a green tea extract to
provide a green tea mixture.
[0076] Concentration of non-polymer catechins: 0.18 wt. %
[0077] Percentage of catechingallates in total non-polymer
catechins: 46 to 57 wt. %
[0078] pH after sterilization: 6.2
[0079] To an aliquot of the green tea mixture prepared in the
above, one of the various activated clays shown in Table 1 was
added in an amount of 0.15 wt. % as an outer percentage. The
resulting mixture was stirred at room temperature (25.degree. C.)
for 10 minutes, followed by the filtration through a 0.8-.mu.m
membrane filter. The thus-obtained green tea mixture was filled in
a heat-resistant glass container. After the head space of the
container was purged with nitrogen gas, the container was sealed
and subjected to sterilization at 121.degree. C. for 10 minutes in
an autoclave. Subsequent to the completion of the sterilization,
the green tea mixture was immediately chilled to 30.degree. C. or
lower, and the content of iron in the green tea mixture and the
lightness (L-value) and pH of the green tea mixture were
measured.
[0080] Relationships between the activated clays and the iron
contents in the corresponding green tea mixtures of Examples 1-2
and Comparative Examples 1-2 are shown in Table 1.
1TABLE 1 Example 1 Example 2 "GALLEON "GALLEON EARTH .TM. V1" EARTH
.TM. NS" Comp. Ex. 1 Comp. Ex. 2 (product of (product of "SA 35"
"SA 80" Mizusawa Mizusawa (product of (product of Chemical Chemical
Nippon Nippon Industries, Industries, Kasseihakudo Kasseihakudo
Activated clay Ltd.) Ltd.) Co., Ltd.) Co., Ltd.) Iron content
[mg/kg] 0.5 0.8 1.0 1.2 L-value [--] 78 74 69.5 68
[0081] Test 2
[0082] Packaged green tea beverages of Examples 3-7 and Comparative
Examples 3-4 obtained in a similar manner as in Test 1 except for
the use of the activated clays shown in Table 2 were stored at
55.degree. C., and were observed with time for the development of
dregs. The results are shown in Table 2.
2TABLE 2 Example 3 Example 4 Example 5 Example 6 Example 7 "GALLEON
Same as in "GALLEON Same as in "GALLEON Comp. Ex. 3 Comp. Ex. 4
Activated clay EARTH .TM. NV" Ex. 3 EARTH .TM. V1" Ex. 5 EARTH .TM.
NS" "SA 35" "SAI" Amount added [wt. %] 0.15 0.30 0.15 0.30 0.15
0.15 0.15 Color tone No problem No No problem No problem No problem
Changed Changed immediately problem into a dark into a dark after
green color green color adsorption treatment Occurrence day
7.sup.th day 21.sup.st day 7.sup.th day 11.sup.th day 5.sup.th day
4.sup.th day 4.sup.th day of dregs Overall ranking feasible
feasible feasible feasible feasible infeasible infeasible
[0083] Test 3
[0084] Packaged green tea beverages of Examples 8-9 obtained in a
similar manner as in Test 1 except for the use of the zeolite shown
in Table 3 were stored at 55.degree. C., and were observed with
time for the development of dregs (as sterilization conditions,
however, UHT sterilization was conducted at 138.degree. C. for 30
seconds) The compositions and ranking results of the packaged green
tea beverages of Examples 8-9 and a packaged green tea beverage not
subjected to the contact-treatment with the zeolite (untreated
product) are shown in Table 3.
3 TABLE 3 Untreated Example 8 Example 9 product Activated clay
Zeolite P Same as -- in Ex. 8 Amount added [wt. %] 0.05 0.1 Color
tone immediately No No after adsorption treatment problem problem
Occurrence day of dregs 13.sup.th day 16.sup.th day 2.5.sup.th day
Overall ranking feasible feasible infeasible Analysis data of
packaged beverages Concentration of [wt. %] 0.18 0.18 0.18
non-polymer catechins (A)/(B) -- 1.2 1.1 1.1 Magnesium ions [mg/kg]
21 20 21 Calcium ions [mg/kg] <1.0 <1.0 <1.0 Aluminum ions
[mg/kg] 17 28 4.8 Silicon ions [mg/kg] 15 27 2.3
[0085] From the results of Tables 1-3, it was confirmed that the
occurrence of dregs in a packaged green tea beverage could be
delayed to a target day, that is, to the 5.sup.th day at 55.degree.
C. (equivalent to 6 months when stored at room temperature) or
longer by contact-treatment with the specific aluminosilicate.
* * * * *