Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
Bottleable Green Tea Beverage
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The present invention relates to a bottleable green tea beverage
containing a
high concentration of catechins; in particular, the invention relates to a
bottleable green
tea beverage having an inhibitory effect on the development of sediment during
long-
term storage when sold hot; furthermore, with improved palatability of the
taste
provided by the catechins.
RELATED ART STATEMENT
100021 Green tea beverage is an enjoyable drink, as it is a tea beverage that
balances
taste, such as astringency, flavor, and bitterness. Furthermore, recently,
with the change
in lifestyle together with the expectation of catechins' contribution to
health and the
demand for palatability emphasizing the taste that catechins have, bottleable
green tea
beverages containing high concentrations of catechins have been developed.
[0003] Japanese Patent Publication No. 3329799 and Japanese Patent Publication
No.
3338705 disclose a bottleable beverage and a method for preparing a bottleable
beverage that determines the mixing proportion and the concentrations of non-
epicatechins and epicatechins, and Japanese Patent Publication No. 3342698 and
Japanese Patent Publication No. 3360073 disclose a bottleable beverage
containing a
circular dextrin or a water-soluble macromolecule with the object of
preventing the
occurrence of sediment in a bottleable beverage containing non-epicatechins
and
epicatechins.
SUMMARY OF THE INVENTION
100041 As "primary sediment" starts to deposit immediately after beverage
preparation, a common green tea beverage is prepared by completely removing
this
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"primary sediment" in the preparation process and then filling a container.
However, a frequently-arising problem is that, after the container has been
filled,
"secondary sediment" (distinct from "primary sediment"; hereinafter, in the
present
invention, this "secondary sediment" is simply referred to as "sediment")
occurs
over time during conservation in the form of supernatant, white cloud, flock
(cotton), or precipitate. In particular, when selling a heated green tea
beverage
bottleable in a PET bottle, the heating promotes the occurrence of sediment,
and
the sediment occurring inside the container is an important issue, not only to
the
extent that the flavor and taste of green tea beverage are compromised, but
also
to the extent that the value of the product will be lost due to its poor
appearance.
In this case, the higher concentration of catechins included, the more
sediment
produced. In addition, a bottleable green tea beverage containing high
concentrations of catechins also has the problem of a bad balance occurring
between astringency and other tastes, lacks palatability, and even unpleasant
feelings are felt.
[0005] It is an object of the present invention to provide a bottleable green
tea
beverage having a high concentration of catechins with high biological
functionality, nonetheless, clarity can be maintained, and flavor and quality
are
satisfactory from the viewpoint of palatability, and, in particular, a
bottleable green
tea beverage appropriate for selling hot.
[0006] As a result of earnest studies in view of the aforementioned problems
in
bottleable green tea beverage containing a high concentration of catechins,
the
present inventors discovered that, in a bottleable green tea beverage
containing a
high concentration of catechins, the occurrence of sediment in the bottleable
green tea beverage was related to the concentration of glutamic acid and
diffuse
transmittance and completed the present invention.
[0007] The present invention provides a bottleable green tea beverage
containing a green tea extract obtained by extracting green tea leaves with
water,
wherein the beverage:
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(i) contains both epigallocatechin gallate (EGCg) and gallocatechin
gailate (GCg) at a total content of 380 mg/I to 1,500 mg/I, provided that GCg
is
contained at a higher content than that of EGCg, and glutamic acid at a
content of
20 mg/I to 120 mg/I, and
(ii) has a diffuse transmittance of 1.0 % or less.
[0008] In addition, the invention provides the above bottleable green tea
beverage, wherein the product temperature of the bottleable green tea beverage
is 50 C to 70 C.
[0009] In addition, the invention provides the above bottleable green tea
beverage, wherein the pH is from 5 to 7.
[0010] According to the present invention, among the catechins, EGCg and
GCg, which are effective in physiological function, can be effectively
ingested.
Further, development of sediment can also be prevented during long-term
conservation when sold hot, while at the same time, the flavor and taste that
the
green tea beverage has intrinsically can be maintained and improved.
Consequently, a bottleable green tea beverage containing high concentrations
of
catechins can be provided, which is suitable for selling not only from
refrigerated
to ordinary temperature, but also up to hot temperature.
[0011] Note that, in the present invention, a "green tea beverage" means a
beverage containing green tea extract, which is obtained by extracting green
tea
leaves, and preferably is a beverage containing 50% or more of the extract.
[0012] A "bottleable green tea beverage" means a green tea beverage, which is
a green tea beverage that can be drunk without diluting, and which can be
provided in the form of a conventional container similar to conventional
beverages,
such as a formed container made of plastic, for instance, a formed container
with
polyethylene terephthalate as a main component (so-called PET bottle), a metal
can, a paper container combined with a metal foil or a plastic film, or a
bottle.
[0013] In addition, in the present invention, "selling hot" means warming a
bottleable green tea beverage up to a temperature that allows provision to a
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,... ...............:...
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consumer, or the like, in a warm state and maintaining the beverage at this
temperature. For instance, this means heating a bottleable green tea beverage
by
direct exposure, conduction, or radiation from a 50 C to 120 C heat source, or
by
a microwave, or the like, maintaining the product temperature of the
bottleable
green tea beverage product at 40 C to 100 C, preferably at 50 C to 70 C, among
which 55 C to 60 C is preferred, and providing a consumer or the like, with
the tea
while this temperature is kept.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] In the following, an embodiment of the beverage of the present
invention
will be described. However, the scope of the present invention is not limited
to the
embodiment described below.
[0015] The bottleable green tea beverage related to the present embodiment is
a bottleable green tea beverage, which contains a green tea extract obtained
by
extracting green tea leaves, containing both epigallocatechin and
gallocatechin
gallate at a total content of 380 mg/I to 1500 mg/I of epigallocatechin
gallate and
gallocatechin gallate, provided that gallocatechin gallate is contained at a
higher
content than epigallocatechin gallate, additionally containing 20 mg/I to 120
mg/I of
glutamic acid, and having a diffuse transmittance of 1.0% or less.
[0016] Epigallocatechin gallate (hereinafter referred to as EGCg) and
gallocatechin gallate (hereinafter referred to as GCg) are compounds with
extremely strong bitterness and astringency, while at the same time they are
known to be useful compounds with high biological activity and can be
determined
and quantified by a method using high performance liquid chromatography
(HPLC) that uses detection at ultraviolet wavelengths.
[0017] EGCg, which is an epimer catechin, is a compound in which a catechin
backbone and gallic acid are ester-bonded and can be obtained by a method well
known in the art, or a method that will be well known in the future.
Specifically, as
EGCg exists in natural plants, including tea leaves, it can be obtained by
extraction from a natural plant with water or hot water, or a water soluble
organic
solvent, such as ethanol, or a mixture thereof. Furthermore, in order to
increase
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the content in EGCg, performing concentration or separation/purification is
preferred.
[0018] GCg, which is a non-epimer catechin, almost does not exist in natural
plants, including tea leaves. However, it can be obtained, for instance, by
heat
treatment of EGCg at approximately 80 C or more to promote heat isomerization
(epimerization).
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[0019] That is to say, by heating at approximately 80 C or above, purified
EGCg or a
mixture containing EGCg or a catechin composition containing EGCg, such as a
tea
extract or an infusion, to promote heat isomerization of EGCg, the
concentration in
GCg content can be increased. In addition, concentration or
separation/purification
from this heat-treated compound is also possible to elevate the concentration
of GCg.
[0020] In order to include EGCg and GCg, a catechin composition containing
EGCg
and GCg, such as a tea extract or a commercially available tea extract can be
added.
[0021] One or more species among purified EGCg and GCg can be added and mixed
so that the composition of EGCg and GCg becomes as desired.
[0022] The glutamic acid used in the present embodiment is preferably L-
glutamic
acid or sodium L-glutamate salt. In addition, any grade of glutamic acid, for
food
additive use, for medicinal use or for reagent use, can be used. In addition,
materials
containing glutamic acid derived from a natural compound can also be used,
among
which, from the viewpoint of flavor, a material derived from tea is preferred.
For
instance, a highly concentrated green tea extract or an extract in which the
concentration in glutamic acid has been elevated by removing catechins,
polysaccharides, and the like from a green tea extract can be used. The
glutamic acid
contained in the green tea beverage can be quantified using the HPLC method
and an
amino acid analyzer.
[0023] In addition to catechins, amino acids are known to contribute to a
green tea
beverage as components related to the taste (sweet taste, pleasant taste) of a
common
green tea beverage. The amino acids contained in a green tea beverage are
theanine,
glutamic acid, aspartic acid, arginine, serine, and the like, and these are
believed to
amount to 90% or more of the total amino acid contained in a green tea
beverage (Shin
Chagyo Zensho, 8th Edition, Chamber of Tea Association of Shizuoka Prefecture,
1988).
[0024] Among these, glutamic acid and salt thereof, in addition to being known
as
flavorants and food additives as pleasant taste components, are known as
additives
related to alleviating bitter taste and astringency of food and medicine
(Refer to, for
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instance, Japanese Patent Application Laid-Open No. 2000-204036, Japanese
Patent
Application Laid-Open No. 2001-69961, and Japanese Patent Application Laid-
Open
No. 2003-160484). In addition, Nakagawa reports the variation of taste
structure and
palatability in a case where glutamic acid and sucrose were added to a green
tea
simultaneously (Muneyuki Nakagawa, Taste and Chemical Components of Green Tea,
Tea Research Journal, Vol. 40, 1-9, 1973). According to this, it is reported
that, when
the concentrations of glutamic acid and sucrose added were raised, the
intensities
regarding bitter taste and astringency tended to increase with a glutamic acid
concentration of 1%; these intensities decreased with an addition of 2% to 4%,
and
palatability decreased with the addition of glutamic acid and sucrose, the
taste
becoming unpleasant and not qualifying as that of a green tea.
[0025] It is important that bottleable green tea beverage related to the
present
embodiment has a diffuse transmittance of 1.0% or less, and being from 0.1% to
1.0%
is important, taking measurement limitation into consideration. If 1.0% or
less,
occurrence of sediment can be prevented, even when serving bottleable green
tea
beverage for selling hot.
[0026] Regarding adjustment of diffuse transmittance, the adjustment can be
performed by supplying a green tea extract, which is to be a raw material of
the
bottleable green tea beverage, to an ultrafiltration step by sampling a
portion from any
of the green tea extracts immediately after the ultrafiltration step or before
and after the
heat sterilization step, or a bottleable green tea beverage immediately after
manufacture,
measuring the diffuse transmittance for each lot and managing adequately with
the
criteria of 1.0% or less. In addition, it has been verified that, once
adjusted, the diffuse
transmittance almost does not change, even if the bottleable green tea
beverage is
stored under heat (for two weeks at 60 C).
[0027] Even if the diffuse transmittance is more than 1.00%, in the present
invention,
the diffuse transmittance is taken as within the criteria of 1.0% or less as
long as it can
be rounded to the first decimal place and become include the range of 1.0% or
less, as
long as the value allows occurrence of sediment to be prevented.
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[0028] Here, the diffuse transmittance is measured according to JIS K7105.
Regarding diffuse transmittance, a relationship exists between the total light
transmittance and haze as in the following formula:
[0029] (Formula 1)
Haze (%) = (diffuse transmittance/total light transmittance) x 100
[0030] The diffuse transmittance can be obtained, using a commercially
available
hazemeter, by placing a sample in a glass cell whose optical path length is
known and
directly measuring the transmitted scattering light.
[0031] (Method for Preparing a Bottleable green tea beverage)
[0032] The bottleable green tea beverage related to the present embodiment can
be
prepared by, for instance, extracting green tea leaves with water or hot
water, thereafter,
mixing a catechin composition containing predetermined catechins to adjust the
quantities of EGCg and GCg, furthermore, adding glutamic acid to adjust this
quantity,
while at the same time performing ultrafiltration so that the diffuse
transmittance of the
product becomes 1.0% or less, and in other steps by a similar method to common
green
tea beverages. Natural tea flavor can be drawn according to such a preparation
method,
which is preferred. In the following, one aspect of the method for preparing
the
bottleable green tea beverage related to the present embodiment will be
described;
however, the invention is not limited to this embodiment.
[0033] (Raw Tea Leaves)
[0034] As long as they are leaves collected from a tea plant (scientific name:
Camellia sinensis), any tea species can be considered as the tea leaves to be
used as
raw materials, without limitation to the type, production region, harvest
period, harvest
method, cultivate method thereof, and the like. Fresh tea leaves and the like
(containing
leaf and stem) can also be used as raw tea leaves. In addition, any type among
Sen-cha,
Kamairi-cha, Kabuse-cha, Gyokuro, Ten-cha, Matcha, Ban-cha, Houji-cha, steamed
Tamaryoku-cha, pan-fired Tamaryoku-cha, Ureshino-cha, Aoyagi-cha, and the like
can
be used as raw tea leaves, as long as it is crude tea obtained by crude tea
processing,
which stops enzymatic activity by such means as steaming or roasting of these
fresh tea
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leaves and the like, or refined tea based thereon. In addition, two or more
types of these
crude teas or refined teas may be combined, and preparation may include a
flavorant.
[0035] (Extraction Step)
[0036] Extraction of green tea leaves that allows extraction of green tea
component
to be performed taking the flavor into account is sufficient, with no
particular
limitation on the extraction method, extraction conditions, and the like. For
instance,
the extraction temperature range can be from cold water to hot water. In
addition, an
extract extracted with cold water and an extract extracted with hot water can
be
combined and used. The settings for the amount of extraction water and the
extraction
time can be set at will to suit the extraction temperature range and the
required
extraction efficiency. Also, the extractor only needs to have a structure that
allows
sufficient extraction work to be carried out, and, for instance, a kneader or
the like can
be used. Stirring and pressure adjustment (pressurized extraction) are
adequately
performed as necessary during extraction. In addition to pure water, hard
water, soft
water and ion-exchanged water, ascorbic acid-containing aqueous solution, pH-
adjusted water, and the like can be given as examples of extraction water used
in the
extraction.
[0037] Adequately, the green tea extract obtained by extraction is cooled to
the order
of 5 C to 40 C as necessary; at the same time, or before or after, ascorbic
acid, sodium
ascorbate or the like is added to the green tea extract as necessary, which is
adjusted to
be acidic (pH 4 to 5). By carrying out cooling or acidity adjustment, or both,
of the
green tea extract, oxidation of the extracted components can be prevented,
while at the
same time components causing primary sediment can be precipitated and the
efficiency
of filtration carried out in the subsequent step can be increased.
[0038] (Ultrafiltration Step)
[0039] Next, the green tea extract extracted as described above is subjected
to
ultrafiltration. Ultrafiltration allows the diffuse transmittance to be 1.0%
or less while
keeping the original flavor of green tea, and as a result, the occurrence of
sediment
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when the green tea extract is turned into bottleable green tea beverage can be
suppressed suitably.
[0040] In the present embodiment, ultrafiltration means filtration
(separation) that
removes substances of roughly 1 m or larger, and, for instance, filtration by
diatomaceous earth, filter filtration, MF membrane separation, UF membrane
separation, and the like can be cited, among which kieselguhr filtration is
preferred. In
addition, two or more of these filtration methods may be used concomitantly.
[0041] Here, kieselguhr filtration is a cake filtration using diatomaceous
earth as a
filter aid. Diatomaceous earth is the earth resulting over long years from
phytoplanktons called diatoms which deposited at the bottom of the sea or the
bottom
of a lake and fossilized, accumulating microscopic diatom clusters. As the
diameter is
from several to several tens of micrometers, and there are numerous
microscopic holes
of 0.1 m to 1.0 m on the surface, forming a compact cake layer of filter aid
on a wire
mesh or a filter cloth allows a clarified solution to be obtained at
filtration time. The
main component of diatomaceous earth is silica (Si02), in particular,
amorphous silica,
those purified by firing being generally used in filter aid applications.
[0042] Diatomaceous earth can be used as long as it is diatomaceous earth used
as a
filter aid, such as diatomaceous earth ore that has been ground and dried, or
ground and
dried and further fired or flux fired, among which a kieselguhr filter aid
with 0.05 to
0.1 Darcy is preferably used. Preparation of a much clearer bottleable green
tea
beverage is possible by using a kieselguhr filter aid with 0.05 to 0.1 Darcy.
[0043] "Kieselguhr filter aid with 0.05 to 0.1 Darcy" means a kieselguhr
filter aid
with a Darcy transmittance K in the range of 0.05 to 0.1. "Darcy transmittance
K" is an
index to indicate the permeability of a filter aid and can be determined by
water
permeation method or air permeation method.
[0044] In addition, for the diatomaceous earth used in the present embodiment,
the
use of diatomaceous earth from which iron has been removed by elution with
acid
treatment is preferred. This is not only because iron influences taste in
green tea
beverages, but additionally because it is also the cause of browning. In
addition,
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another filter aid, such as silica gel, pearlite, or cellulose may be mixed
and used with
diatomaceous earth.
100451 As a method for kieselguhr filtration, it suffices to add diatomaceous
earth of
a desired amount to green tea extract, carry out suitable stirring or auto-
circulation by a
pump, to contact green tea extract and diatomaceous earth for a predetermined
time,
then, separate and remove diatomaceous earth with a filtration unit. In so
doing, the
batch method or the semi-continuous method can be chosen according to the
amount of
green tea extract treated. As one example of semi-continuous method, it
suffices to
precoat the support surface of the membrane filter with diatomaceous earth,
and while
injecting (body feeding) kieselguhr filtration agent as necessary to the green
tea extract,
which becomes a stock solution, send the stock solution to the precoated
filtration unit.
In so doing, as preparing two or more filtration units to carry out cake
extraction and
reverse-wash with one during filtration with the other is effective, it is
preferred.
[00461 It suffices to adjust the amount of diatomaceous earth used and the
contact
time depending on the amount or concentration of the stock solution of green
tea
extract used. For instance, when the green tea extract is prepared using an
amount of
extraction water of 20 to 100 fold with respect to the raw tea leaves, if, in
terms of total
amount of precoating and body feed, 0.1 to 5 mass percent per green tea
extract is
contacted for 5 minutes to 120 minutes, the diffuse transmittance can suitably
become
1.0% or less.
[00471 In order to eliminate primary sediment occurring during extraction, a
coarse
filtration step can also be introduced prior to the ultrafiltration step.
Here, the coarse
filtration step is a step for eliminating extraction residues, such as tea
leaves and large
particles. For instance, stainless filter, flannel cloth, strainer,
centrifugal separation,
and other general filtration method to eliminate extraction residues can be
suitably used
in combination. In addition, primary sediment may be eliminated at the same
time in
the ultrafiltration step.
[0048] (Combination)
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[0049] Next, a predetermined catechin composition is added to the green tea
extract
prepared as described above to adjust the amount of EGCg and GCg so that the
total
concentration of EGCg and GCg is 380 mg/l to 1500 mg/l, preferably 590 mg/l to
1000
mg/l.
[0050] A green tea beverage containing a total concentration of 380 mg/l to
1500
mg/1 in EGCg and GCg allows EGCg and GCg to be effectively drunk, which, among
the catechins, are effective in physiological function and allows bottleable
green tea
beverage having taste palatability to be provided.
[0051] The catechin composition can be prepared by means of adjustment of the
amount of EGCg and GCg by adding one or more species of purified EGCg and GCg.
In addition, tea extracts obtained by extracting tea leaves from non-fermented
tea,
semi-fermented tea, or fermented tea with water, hot water, or water-soluble
organic
solvent, and further carrying out a predetermined purification and
concentration, and
commercially available tea extracts can also be used to adjust the amount of
EGCg and
GCg. For instance, THEA-FLAN*30E, THEA-FLAN* 30A, THEA-FLAN*W, THEA-
~ *
FLAN 90S (all. manufactured by ITO EN Co., LTD.), SUNFLAVONE HG (Taiyo
Kagaku Co., Ltd.), POLYPHENON 70A, POLYPHENON E (Mitsui Norin Co., Ltd.),
Theacalone* 90S (Tokiwa Phytochemical Co., Ltd.), CTP-95 (Citimex),
Greenselect *
(Indena), Tea-Fresh*80S (Japan Chlorophyll Co., Ltd.), TEAVIGO*(DSM
Nutritional
Products), or the like can be used.
[0052] Here, as an adjustment of the proportion of EGCg and GCg, an adjustment
can be carried out, in which only purified EGCg or a tea extract containing
large
amounts of EGCg is added, treated with heat in a subsequent step, and
isomerized into
GCg from EGCg to raise the proportion of GCg. In particular, performing heat
isomerization of EGCg at the same time as heat sterilization of the bottleable
green tea
beverage to include EGCg and GCg is suitable. Although the proportion of EGCg
and
GCg varies due to heat isomerization, the amount of catechins almost does not
change
if close to pH neutrality and below.
*Trade-mark 1 1
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[0053] The bottleable green tea beverage related to the present embodiment can
also
be prepared by obtaining a temporary intermediate by removing a portion or the
entirety, preferably from 50% to 100%, more preferably from 70% to 100%, of
the
catechins contained in the green tea extract immediately after extraction and
then
adding the above-mentioned catechin composition, such as a tea extract.
[0054] As a method for removing catechins from green tea extract, removal
methods,
such as resin adsorption by a synthetic adsorption resin or the like, membrane
separation by an ultrafiltration membrane or a reverse osmosis membrane, gel
filtration
chromatography, solvent extraction, can be used. Among these, resin adsorption
using
PVPP, which is a synthetic adsorption resin, as it allows catechins to be
adsorbed
selectively, is suitable as a method for removing catechins. Furthermore, the
method
for removing catechins, which is an invention by the present applicants
(Patent
3315304), is particularly suitable. In so doing, the amount of the synthetic
adsorption
resin PVPP is adequately selected depending on the quantity or concentration
of
catechin composition contained in the green tea extract.
[0055] Next, glutamic acid is added to the green tea extract to adjust the
concentration of glutamic acid to be from 20 mg/l to 120 mg/l, preferably from
24 mg/l
to 113 mg/l, and more preferably from 38 mg/l to 113 mg/1.
100561 In general, since glutamic acid contained in green tea leaves is
extracted in a
green tea extract, the concentration of glutamic acid contained in a green tea
extract
depends on the concentration of green tea extract. Consequently, it suffices
to adjust
the amount of glutamic acid added according to the extraction conditions of
green tea
leaves. Furthermore, it suffices to add and dissolve the glutamic acid before
the green
tea extract extracted in the extraction step becomes held in a container, and
preferably,
a step for adjusting the amounts of EGCg and GCg, then adding and dissolving
the
glutamic acid may be established. In addition, a material containing a high
concentration of glutamic acid may be added as well.
[0057] In addition, an additive, such as oxidation inhibitor, emulsifying
agent,
preservative, pH adjuster, flavor, seasoning agent, edulcorant, acidulant,
quality
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stabilizer, alone or in combination, may be mixed in the bottleable green tea
beverage
related to the present embodiment.
[0058] For instance, vitamin C (ascorbic acid or ascorbic acid salt), vitamin
E,
cysteine, and the like can be used as oxidation inhibitor; in particular,
inclusion of
0.005 to 0.2 mass percent of vitamin C is adequate. In addition, if the pH is
adjusted to
to 7, and among this range, to 5.5 to 6.5, using sodium bicarbonate, potassium
carbonate, or the like as a pH adjuster, the flavor and stability during
conservation of
the green tea beverage can be kept, which is therefore preferred.
[0059] For instance, glucose, fructose, isomerized liquid sugar syrup,
fructooligosaccharide, emulsified oligosaccharide, soybean oligosaccharide,
cyclodextrin, aspartame, rakanka extract, and the like may be used as
edulcorant, and
in particular, including 0.01 to 1.0 mass percent of cyclodextrin is adequate.
By mixing
these additives alone or in combination, a more suitable beverage can be
provided. In
addition, the beverage can be suitably diluted with water to adjust the
concentration of
catechins and mixture to be at drinking concentration.
[0060] (Containment)
[0061] The bottleable green tea beverage related to the present embodiment can
be
provided in the form of a conventional container similar to conventional
beverages,
such as a formed container made of plastic, for instance, a formed container
with
polyethylene terephthalate as a main component (so-called PET bottle), a metal
can, a
paper container combined with a metal foil or a plastic film, or a bottle, and
is prepared
by filling these containers with the green tea beverage prepared as described
above.
During this filling, if the filling environment or the container interior is
substituted
with inert gas, such as nitrogen gas, oxidation of the bottleable green tea
beverage is
adequately prevented.
[0062] Further, if a metal can is to be filled, heat sterilization is carried
out under
conditions defined by Food Sanitation Law after the container has been filled.
For
those containers that cannot be retort sterilized, such as PET bottle and
paper container,
a method is adopted in which heat sterilization is carried out under similar
sterilization
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conditions as described above, for instance, with a plate heat exchanger and
the like,
then cooling to a given temperature and filling the container. In addition,
under sterile
conditions, a container can be filled by mixing another component.
Furthermore,
operations, such as heat sterilizing under acidic conditions, then returning
the pH to
neutrality under sterile conditions, or heat sterilizing under neutral pH
conditions, then
adjusting the pH under sterile conditions, are also possible.
[0063] (Evaluation of Diffuse Transmittance)
[0064] The diffuse transmittance of green tea beverage related to the present
embodiment is measured using a hazemeter and managed with the criteria that it
is
1.0% or less.
[0065] It suffices to carry out the measurement of diffuse transmittance in
any among
a green tea extract immediately after an ultrafiltration step, or before or
after a heat
sterilization step, or a bottleable green tea beverage immediately after
manufacturing.
A manufacturing condition is preferably applied, where a portion of each lot
of a green
tea beverage is sampled and the diffuse transmittance is measured as described
previously so that it is 1.0% or less, for among which, a green tea beverage
immediately prior to filling in case a metal can, or a green tea beverage
after heat
sterilization in case a container that cannot be retort sterilized, such as a
PET bottle or a
paper container.
[0066] In general, for a green tea beverage subjected to ultrafiltration under
the
conditions described previously, the diffuse transmittance is 1.0% or less.
However, in
the event the diffuse transmittance is measured and the value exceeds 1.0%, it
suffices
to subject it to ultrafiltration again.
EXAMPLE
[0067] Examples of the present invention will be shown in the following;
however,
the scope of the patent is not limited to the examples.
[0068] (Quantitation of Catechins)
14
CA 02541255 2006-03-29
[0069] The HPLC gradient method was used for the component analysis of
catechins.
The analytical conditions were as follows:
Column: YMC J'sphere ODS-H80 cp 4.6x250 mm
Mobile phase:
Gradient elution method using
Solution A: acetonitrile:water:phosphoric acid = 5:94.9:0.1
Solution B: acetonitrile:water:phosphoric acid = 50:49.9:0.1
(The programs for the gradients are shown in Table 1.)
Amount injected: 10 L
Flow rate: 1.0 ml/min.
Detection: UV 230 nm
Column temperature: 40 C
[0070] [Table 1]
Program (min) Flow rate Solution A Solution B
(ml/min) (%) (%)
INITIAL 1.0 95 5
5.0 1.0 95 5
10.0 1.0 90 10
15.0 1.0 90 10
25.0 1.0 80 20
40.0 1.0 80 20
45.0 1.0 20 80
55.0 1.0 20 80
60.0 1.0 95 5
74.0 1.0 95 5
CA 02541255 2006-03-29
[0071] Calibration curve construction method: Each catechin reference product
(manufactured by Kurita Water Industries Ltd) was diluted with distilled water
to
obtain three concentrations in a range on the order of 10 ppm to 100 ppm to
prepare the
standard solutions. Standard solutions at each concentration were respectively
injected
into the HPLC, and a three-point calibration curve was constructed beforehand
from
the obtained peak area values and the concentrations.
[0072] Sample preparation method: 5 ml of sample to be quantified and
characterized
was accurately measured, introduced into a 50 ml volumetric flask, the volume
was
adjusted with distilled water, the resulting solution was filtered with a 0.45-
m
membrane filter, then injected into HPLC and quantified with the three-point
calibration curve method described previously.
[0073] When a value was shown to exceed a range of the calibration curve, the
dilution factor was further increased to allow for a quantitation within the
limits, and a
reanalysis was performed.
[0074] (Separation and Quantitation of Glutamic Acid and Theanine)
[0075] Glutamic acid and theanine were quantified by the HPLC method using
fluorescence detection with the ortho-phthalaldehyde reaction solution. The
analytical
conditions were as follows:
Column: Wakosil-II 5C18HG cp 4.6 x 250 mm
Mobile phase:
Gradient elution method using:
Solution A: 50 mM sodium acetate (adjusted to pH 6.0 with acetic acid)
Solution B: 100% acetonitrile
(The programs for the gradients are shown in Table 2.)
Color reagent: o-phthalaldehyde reagent (OPA)
16
CA 02541255 2006-03-29
o-phthalaldehyde in the amounts of 246 mg was dissolved in 20 ml of 0.1 M
boric acid buffer solution (adjusted to pH 10.0 with 1 M NaOH), and 200 L of
2-
mercaptoethanol was added.
Amount injected: 5 m each of OPA, sample and OPA; 15 m total
Flow rate: 1.0 ml/min
Detection: fluorescence detector with excitation wavelength at 340 nm and
detection wavelength at 455 nm
Column temperature: 40 C
[00761 [Table 2]
Program (min) Flow rate Solution A Solution B Gradient curve
(ml/min) (%) (%)
INITIAL 1.0 88 12 *
10.00 1.0 88 12 11
10.01 1.0 84 16 11
25.00 1.0 84 16 11
25.01 1.0 82 18 11
40.00 1.0 82 18 11
45.00 1.0 55 45 6
60.00 1.0 55 45 11
61.00 1.0 88 12 6
76.00 1.0 88 12 11
[0077] Calibration curve construction method: glutamic acid (Wako Pure
Chemical Industries, Ltd.), theanine (manufactured by Tokyo Kasei Kogyo Co.,
Ltd.)
reference products were respectively diluted with distilled water to obtain
three
concentrations in a range on the order of 1 ppm to 30 ppm to prepare the
standard
solutions. Standard solutions at each concentration were respectively injected
into the
17
CA 02541255 2006-03-29
HPLC, and a three-point calibration curve was constructed from the obtained
peak area
values and the concentrations.
[0078] Sample preparation method: 5 ml of sample was accurately measured,
introduced into a 25-ml volumetric flask, the volume was adjusted with
distilled water,
the resulting solution was filtered with a 0.45- m membrane filter, then
injected into
HPLC and quantified by the standard reagent solution with the three-point
calibration
curve method.
[0079] When a value was shown to exceed a range of the calibration curve, the
dilution factor was further increased to allow for a quantitation within the
limits, and a
reanalysis was performed.
[0080] (Measurement of Diffuse Transmittance)
[0081] The diffuse transmittance was analyzed for beverages canned immediately
after manufacturing and for canned beverages stored after manufacturing at 60
C for
two weeks, according to the method described in JIS K7105, using the hazemeter
HM-
150 manufactured by Murakami Color Research Laboratory at a product
temperature of
25 C.
[0082] (Evaluation of Sediment Occurrence)
[0083] The situation of sediment occurrence was evaluated visually for green
tea
beverages bottled in heat-resistant bottles after storage at 4 C or 60 C for
two weeks.
-: none
+: slight sedimentation (fine powders present)
++: some sedimentation
+++: fair amount of sediment
++++: large amount of sediment
+++++: extremely large amount of sediment
[0084] (Sensory Evaluation)
[0085] For the sensory characteristics, beverages stored at 25 C for two
weeks, and
beverages from samples stored at 25 C, which were warmed to 60 C immediately
18
CA 02541255 2006-03-29
before sensory evaluation, were scored by five trained examiners according to
the
evaluation sheet of Table 3 for each of "irritation upon mouth contact,"
"astringency,"
and "thickness," which characterize a green tea beverage, using a seven-stage
evaluation. In addition, the overall "tastiness" as green tea beverage, which
takes into
account the balance of "irritation upon mouth contact," "astringency," and
"thickness,"
and other tastes, was also evaluated.
[0086] [Table 3]
Score Irritation upon Astringency Thickness Tastiness
mouth contact
1 Extremely strong Extremely Extremely Extremely not tasty,
strong weak not acceptable
2 Strong Strong Weak Not tasty, not
acceptable
3 Rather strong Rather strong Rather weak Rather not tasty, but
acceptable
4 Neither Neither Neither Ordinary
Rather weak Rather weak Rather strong Rather tasty
6 Weak Weak Strong Tasty
7 Extremely weak Extremely Extremely Extremely tasty
weak strong
[0087] (Overall Evaluation)
[0088] The product value as bottleable green tea beverage was assessed by
gathering
the results from the evaluation of sediment occurrence and the sensory
evaluation.
[0089] Excellent: is extremely desirable as heated, ordinary temperature, or
refrigerated bottleable green tea beverage
Good: is suitable as heated, ordinary temperature, or refrigerated bottleable
green tea beverage
19
CA 02541255 2006-03-29
Comparatively poor: is suitable as ordinary temperature or refrigerated
bottleable green tea beverage, but not suited for heating
Poor: not suitable as bottleable green tea beverage
[0090] (Example)
[0091] An extract obtained by extracting 60.0 g of green tea with 2500 ml of
ion-
exchanged water at 60 C for 5 minutes was crudely filtered with a mesh and
then
cooled to 25 C or below. Thereafter, 3.0 g of ascorbic acid was added,
centrifugal
separation (using the SA1 continuous centrifugal separator manufactured by
Westfalia
at a flow rate of 300 1/h, a rotation speed of 10000 rpm, and a centrifugal
sedimentation
surface of 1000 m2) was performed, and then kieselguhr filtration (contact
time: 30
minutes; filtration using 100 g of acid-treated diatomaceous earth with a
Darcy value of
0.1, with 0.15 g/cm2 per filtration area, by pressure) was carried out.
Thereafter 4.0 g
of ascorbic acid and sodium glutamate (manufactured by Hayashi Pure Chemical
Industry, Ltd.; food additive) and epigallocatechin gallate TEAVIGO (DSM
Nutritional
Products) as shown in Table 4 were added so as to obtain various
concentrations to the
kieselguhr-filtered green tea extract; then, water was added as ion-exchanged
water;
furthermore, sodium bicarbonate was used to adjust the pH to 6.0 to 6.1, and
the weight
of the extract was adjusted to 10 kg. After adjustment, the temperature of the
extract
was heated up to 90 C and the solution was canned by filling a steel can.
Next, the
filling beverage was heat sterilized (123 C, 10 minutes) to prepare a
bottleable green
tea beverage. One container of the prepared bottleable green tea beverage was
opened,
a fraction of the green tea beverage inside the container was sampled, and the
concentration of each component and the diffuse transmittance immediately
after
manufacturing were measured. In addition, for sediment observation, a
transparent
heat-resistant bottle was filled separately and heat sterilized as described
previously to
prepare a bottleable green tea beverage.
[0092] The concentration of each component and the results of the above-
mentioned
evaluation from Examples 1 to 6 are shown in Table 4.
[0093] [Table 4]
CA 02541255 2006-03-29
Unit for each component: mg/1
Example Example Example Example Example Example
1 2 3 4 5 6
Bx 0.398 0.392 0.397 0.409 0.281 0.308
pH 6.11 6.09 6.07 6.08 6.10 6.00
EGCg (A) 459.8 470.1 444.6 454.0 182.3 273.1
GCg (B) 540.5 549.5 521.6 532.6 215.0 318.9
A + B 1000.3 1019.6 966.2 986.6 397.3 592.0
8 catechin species 1251.9 1275.6 1208.2 1235.8 602.0 807.0
Glutamic acid 39.9 24.6 77.3 113.1 23.7 25.3
Theanine 15.7 15.7 15.2 14.1 16.2 16.1
Diffuse transmittance %
(immediately after 0.2 0.2 0.1 0.2 0.1 0.1
manufacturing)
Diffuse transmittance %
(after two weeks at 0.3 0.3 0.3 0.2 0.1 0.1
60 C)
Occurrence of sediment
(after two weeks at 4 C) - - - -
Occurrence of sediment
(after two weeks at - - - - - -
60 C)
Irritation upon mouth
contact 4.2 3.0 4.6 5.6 6.2 5.2
(for 25 C drink)
Astringency 3.6 2.8 4.6 5.4 5.8 5.4
(for 25 C drink)
Thickness 4.0 4.0 3.6 3.4 3.0 4.0
(for 25 C drink)
Irritation upon mouth 4.0 3.2 4.8 5.6 6.2 5.2
contact
(for 60 C drink)
Astringency 3.8 3.2 5.4 5.8 6.0 5.2
(for 60 C drink)
Thickness 4.4 4.4 3.6 3.8 3.6 4.2
(for 60 C drink)
Tastiness 3.6 3.0 4.8 5.2 5.0 6.0
21
CA 02541255 2006-03-29
(for 25 C drink)
Tastiness 3.8 3.4 4.8 5.0 5.0 6.0
(for 60 C drink)
Overall score Good Good Excellent Excellent Excellent Excellent
[0094] (Comparative Examples)
[0095] For Comparative Example 1, bottleable green tea beverage was prepared
with
a similar procedure to the Example, except that kieselguhr filtration after
centrifugal
separation was not carried out glutamic acid was not added.
[0096] For Comparative Examples 3 and 5, bottleable green tea beverage was
prepared with a similar procedure to the Example, except that kieselguhr
filtration after
centrifugal separation was not carried out.
[0097] For Comparative Example 2, bottleable green tea beverage was prepared
with
a similar procedure to the Example, except that glutamic acid was not added.
[0098] For Comparative Example 4, bottleable green tea beverage was prepared
with
a similar procedure to the Example, except that the glutamic acid content was
14.1mg.
[0099] The concentration of each component and the results of the above-
mentioned
evaluation for Comparative Examples 1 to 5 are shown in Table 5.
[0100] [Table 5]
Unit for each component: mg/1
Comparative Comparative Comparative Comparative Comparative
Example 1 Example 2 Example 3 Example 4 Example 5
Bx 0.390 0.396 0.398 0.389 0.471
pH 6.03 6.01 6.08 6.05 5.99
EGCg (A) 470.5 466.7 449.8 467.9 494.9
GCg (B) 545.8 539.2 524.0 545.2 575.7
A+ B 1016.3 1005.9 973.8 1013.1 1070.6
8 catechin species 1268.1 1257.3 1217.4 1265.1 1319.3
Glutamic acid 6.3 6.8 38.5 14.1 455
Theanine 12.8 14.9 14.8 14.1 18.6
Diffuse transmittance %
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CA 02541255 2006-03-29
(immediately after 4.6 0.2 4.5 0.2 5.4
manufacturing)
Diffuse transmittance % 4.5 0.2 4.6 0.3 5.3
(after two weeks at 60 C)
Occurrence of sediment - -
(after two weeks at 4 C)
Occurrence of sediment ++++ ++ ++++ + +++++
(after two weeks at 60 C)
Irritation upon mouth
contact 3.6 2.6 4.0 3.0 4.6
(for 25 C drink)
Astringency (for 25 C 2.8 2.4 2.8 2.6 5.0
drink)
Thickness 3.8 3.6 3.2 3.8 4.2
(for 25 C drink)
Irritation upon mouth
contact 3.6 2.8 4.2 3.4 4.4
(for 60 C drink)
Astringency (for 60 C 2.6 2.2 3.4 2.6 5.2
drink)
Thickness 4.2 4.0 3.6 4.4 4.4
(for 60 C drink)
Tastiness 2.8 2.0 2.8 2.4 2.0
(for 25 C drink)
Tastiness 3.0 2.8 4.0 2.8 2.2
(for 60 C drink)
Overall score Poor Poor Poor Compara- Poor
tively poor
[0101] (Discussion)
[0102] Evaluation results for Examples 1 to 6 are shown in Table 4. In
Examples I to
4, with a total concentration in EGCg and GCg of approximately 1000 mg/l
(total
amount of 8 catechin species of approximately 1200 mg/1 to 1300 mg/1) and
various
concentrations of glutamic acid (approximately 25 mg/1 to 110 mg/1), the
occurrence of
sediment could be suppressed in any of the examples. In addition, in the
sensory
23
CA 02541255 2006-03-29
evaluation, "irritation upon mouth contact," "astringency," and "thickness"
were
balanced at both 25 C and 60 C, and it was found that "tastiness" also
increases with
the glutamic acid content.
[0103] In addition, in Examples 5 and 6, with a total concentration in EGCg
and GCg
of approximately 400 mg/l to 600 mg/l (total amount of 8 catechin species of
approximately 600 mg/1 to 800 mg/1) and the concentration of glutamic acid of
approximately 25 mg/l, the occurrence of sediment could be suppressed as in
Examples
I to 4; as for sensory evaluation, the balance of "irritation upon mouth
contact,"
"astringency" and "thickness," and "tastiness" were better for both 25 C and
60 C.
[0104] Consequently, the overall score of bottleable green tea beverages of
Examples
I to 6 being excellent in their conservability at low temperature and when
heated, as
well as their senses at ordinary temperature and when heated, they are
suitable as
bottleable green tea beverages, among which, Examples 3 to 6 were found to be
extremely good.
[0105] Meanwhile, evaluation results for Comparative Examples 1 to 5 are
shown in Table 5. For Comparative Examples 1, 3, and 5, in which kieselguhr
filtration
after centrifugation filtration was not carried out, occurrence of sediment
was observed
noticeably after conservation at 60 C. In addition, for Comparative Examples 2
and 4,
in which kieselguhr filtration was carried out, but glutamic acid content was
less
compared to Examples 1 to 6, the occurrence of sediment was also observed
after
conservation at 60 C.
[0106] In addition, regarding sensory evaluation, in Comparative Examples 1,
2, and
4 with a total concentration in EGCg and GCg of approximately 1000 mg/l (total
amount of 8 catechin species of approximately 1200 mg/l to 1300 mg/1) and
various
concentrations of glutamic acid (approximately 6 mg/1 to 14 mg/1), "irritation
upon
mouth contact," "astringency," and "thickness" were enhanced compared to
Examples
1 to 4 with the same order of catechin concentration, and the overall
"tastiness" was
found to be either similar or less.
24
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[0107] Next, for Comparative Example 5 with a total concentration in EGCg and
GCg
of approximately1000 mg/l (total amount of 8 catechin species of approximately
1300
mg/1) and a concentration in glutamic acid of approximately 455 mg/1, although
"irritation upon mouth contact," "astringency," and "thickness" were balanced
by the
effect provided by the taste of glutamic acid, due to the taste of glutamic
acid being too
pronounced, the extent was not acceptable in terms of overall "tastiness."
[0108] Table 6 shows composition data of a commercial bottled tea beverage
containing catechin in high concentrations (product name: Healthya Ryokucha,
manufactured by Kao, a product exclusively for cold use, purchased in August
2004) as
well as results when an unopened product was heated at 60 C and conserved for
two
weeks. The value of diffuse transmittance prior to heating at 60 C was high at
5.2%; in
addition, occurrence of sediment after conservation at 60 C was also
prominent.
[0109] [Table 6]
Unit for each component: mg/l
Comparative Example 6
Bx 1.033
pH 5.90
EGCg (A) 367.6
GCg (B) 409.5
A + B 777.1
8 catechin species 1763.2
Glutamic acid 26.8
Theanine 99.1
Diffuse transmittance % 5.2
(prior to heat treatment)
Occurrence of sediment ++++
(after two weeks at 60 C)
