Note: Descriptions are shown in the official language in which they were submitted.
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LOW POTASSIUM JUICE, METHOD FOR PRODUCING THEREOF AND FOOD
CONTAINING THE SAME
~'TFT D OF THE INVENTION
The present invention relates to a low potassium juice, a
method for producing thereof and a use thereof, and more
particularly to a low potassium juice with a favorable flavor, a
method for producing thereof and a food in which the low potassium
juice is used as a raw material. The flavor of the potassium juice
is improved by decreasing the concentration of potassium and by
adding a calcium compound thereto. Further, the present invention'
relates to a low potassium juice and a food utilizing the same,
which are suitable for patients suffering from kidney failure who
are allowed to take limited amounts of potassium and to whom
administration of calcium carbonate is necessary.
BACKGROUND OF THE INVENTION
In cells of animals inclusive of humans, potassium mainly
exist in an intracellular fluid and in a pair with sodium which
exists mainly in an extracellular fluid and plays an important role
in maintaining the homeostasis of a living organism as one of major
factor in the acid-base equilibrium. However, since patients
suffering from kidney failure have decreased functions of discharge
of potassium and of maintaining blood ion balance so that they tend
CONFIRMATION COPY
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to suffer from hyperkalemia, hyperphosphatemia, or hypocalcemia.
An extreme increase in serum potassium level may cause the stop
of the heart function and, in the worst cases, fatal situation.
Therefore, patients with kidney failure are subjected to
strict restriction on the uptake of potassium and, in particular,
they cannot freely take fruit or vegetables containing potassium
in large amounts . As described above , patients with kidney failure
tend to be suffering from hyperphosphatemia or hypocalcemia, and
hence administration of calcium carbonate to such patients is
necessary. Further, in the case of those patients who are subjected
to the restriction on the uptake of fruit and vegetables, there
arises a new problem that the contents of meal are unbalanced and
it is difficult to maintain a nutritional balance.
Treatment of juice with ion exchange resins itself is a
technology which has been known for a long time . J . Sci . Food Agric .
( 1966 ) , 17 ( 11 ) , 488-90 reports the use of cation and anion exchange
resins in preventing the precipitation of argot and adjustment of
the acidity of a grape juice. Also, it has been reported a trial
to adjust potassium ion in juices using the ion exchange resins
(Japanese Patent Application Laid-open No.Sho61-209573, Brazilian
Patent Application Laid-open No. 9704147, European Patent
Application Laid-open No. 0339540).
However, foods adjusted to decrease the amount of potassium
ion with ion exchange resins by the prior art have not always been
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satisfactory in respect of health care, taste, texture, nutritional
balance, etc. In the technology described in Japanese Patent
Application Laid-open No. Sho 61-209573, since a decrease in the
potassium content results in a considerable deterioration of the
taste of juice, the amount of depotassification is restricted to
90% or less of the amount of potassium contained in the raw material
juice . That is , the taste is maintained by allowing at least about
10% of potassium to remain. Further reduction in the content of
potassium is not applied.
According to the guideline used in Japan, patients under
maintenance blood dialysis who receives dialysis 3 times a week
are subjected to a strict restriction on the uptake of potassium
to 1.5 g/day. In this case, if the amount of potassium in juice
reamed from fruit or a vegetable is reduced until it is suitable
for drinking by patients with kidney failure, the acidity increases
excessively and the taste is extremely aggravated so that a drinking
having a taste suitable as juice has not been obtained.
Brazilian Patent Application Laid-open No. 9704147 and
European Patent Application Laid-open No. 0339540 disclose methods
for producing depotassified juice containing water-soluble calcium
ions by using calcium type cation exchange resin in order to improve
the degree of deterioration of the taste as described above.
Brazilian Patent Application Laid-open No. 9704147 discloses the
technology of exchanging potassium ions and sodium ions in juice
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with calcium ions using calcium type cation exchange resin.
However, the calcium type cation exchange resin is limited
in the content of water-soluble calcium salt necessary for the
adjustment so that exchange of a large amount of calcium ions is
unrealistic and it is only possible to provide juice which contains
a trace amount of calcium ions in the range where they are
water-soluble as contained in general beverages.
Since use of the calcium type cation exchange resins is
unrealistic, European Patent Application Laid-open No. 0339540
discloses a method for producing low potassium juice using novel
calcium type cation exchange resin . That is , it discloses a method
for producing calcium containing juice using calcium type cation
exchange resin composed of polystyrene resin having sulfon groups ,
crosslinked to 80% with divinylbenzene.
However , also in this case , there are technical barriers , that
is the amount of potassium ions removed and volume of exchange by
the calcium type cation exchange resin. Therefore, the prior art
remains to provide juice still containing potassium ion in an amount
of about 30 % of the total amount of potassium ion contained in juice
before the treatment.
Moreover, nowadays when ion exchange technology has been
improved greatly, a method for the decationation of juice by means
of ion exchange membranes has also been used widely. However, juice,
which has a high solid content, causes clogging of the membrane,
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so that a reduction in the amount of ion is limited to about one
fifth of the rations contained in raw material juice.
As stated above, in the prior art, it has been known to provide
juice by removal of potassium ions using ration exchange resin and
optional addition of calcium by use of calcium type ration exchange
resin. However, there has been a limitation in technology to remove
a sufficient amount of potassium while retaining taste and exchange
a large amount of calcium ions by use of calcium type ration exchange
resin.
Concerning general methods for freeze-drying juice, the
relationship between Bx of the product to be dried and freeze-
drying temperature, the necessity of generating ice composed of
small crystals and so on are disclosed in "Latest fruit juice/fruit
beverage encyclopedia" published on October 1, 1997 by Asakura
Publishing Co., Ltd. page 287 (ISBN 4-254-43060-4). However, no
mention is made of specific treatments of low potassium juice . Next ,
concerning general methods for producing jelly and gummy, their
formula and production method are described in "Encyclopedia of
confectionery" published on May 20 , 2000 by Asakura Publishing Co . ,
Ltd., pages 397-400 (ISBN 4-254-43063-9), but no mention is made
of products containing low potassium juice. Also, as for general
candy, various formulae and production methods are described on
pages 386 to 392 of the above-cited "Encyclopedia of confectionery"
but no mention is made of products containing low potassium juice
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as described above. Furthermore, concerning jelly hot-filled in
a soft container equipped with a mouthpiece having a cap and sealed,
jelly-like fluid drink containing collagen peptide and peach juice
is disclosed in Japanese Patent Application Laid-open No. Hei
11-75726, but no mention is made of products containing low
potassium juice.
It is needless to say that taste is one of the important
elements of food according to the present invention. Foods from
which merely potassium has been removed are not satisfactory to
patients suffering from chronic kidney failure who are compelled
to be subjected to dietary control for a long period of time. This
is a serious problem.
However, scientific clarification of sensation of taste of
humans has not been made sufficiently yet and in actualities , novel
foods and new tastes have been developed by at random screening
and tremendous efforts by food technicians.
An object of the present invention is to solve the problems
associated with the prior art as described above . More particularly,
an object of the present invention is to provide a low potassium
juice produced by the preparation method described below and various
foods such as powdered low potassium juice, jelly, gummy, candy
produced from the low potassium juice as a raw material which not
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only contain a reduced amount of potassium but also have improved
taste and nutritional balance so that it can be taken with good
taste for patients who suffer from malfunction for kidney such as
kidney failure. In addition it is intended for the therapy of
patients with kidney failure, i.e. , control of blood potassium ion
as well as improvement and prevention of hypocalcemia and
hyperphosphatemia with calcium carbonate.
Among others , in the case of patients suffering serious kidney
failure, even the amount of water contained in usual juice imposes
a large load on the kidney to discharge it and in addition uptake
of potassium is strictly limited as described above . On the medical
site under such circumstances , simply rock ice or cube ice is given
to the patients as a tasty material for limited water uptake . In
view of this situation, intensive investigation has been made on
low potassium food having a relatively low water content and
allowing supplemental uptake of energy originated from
carbohydrates and as a result it has been successful to develop
various foods containing low potassium juice as described above,
thus achieving the present invention.
First, to obtain low potassium juice, intensive search and
study have been made in every direction. Decreasing the potassium
content with a use of cation exchange resin resulted in an excessive
increase in acidity so that low potassium juice of fruit and/or
low potassium juice of vegetable which has lost taste could be
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obtained. However, addition of a suitable amount of a calcium
compound selected from calcium carbonate and calcium hydroxide in
the solid state to the juice has neutralized the acidity and improved
the taste so that it could be taken with good taste. Then, it has
been found that the above-described various foods applied from the
low potassium juice as a raw material can be used for the therapy
of patients suffering kidney insufficiency, for the purpose of
maintaining the balance between blood potassium ion and phosphate
ion in the body, and for the purpose of supplying energy to the
body by carbohydrates inevitably added to various foods containing
low potassium juice.
Generally, for the neutralization of acidity, addition of a
basic compound is considered. However, addition of a basic substance
containing potassium or sodium which has been removed from juice
cannot be adopted for juice for patients suffering from kidney
failure who are subjected to restriction on the uptake of potassium
or sodium. Conventional technologies using calcium type cation
exchange resins have limitations on the amount of potassium to be
removed and the volume amount of calcium ion to be exchanged as
described above.
On the other hand, calcium carbonate is a water-insoluble
compound and as described in The Merck Index (12th ed., Merck &
Co. , Inc. , pp271-272) , calcium carbonate has been used widely for
animals or humans as a supplement for calcium ions and as an
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antioxidant . It has been widely administered to patients suffering
from kidney failure as described below in order to suppress the
absorption of phosphoric acid so that juice containing it or various
foods applied from it as a raw material is not only safe when taken
by the patients but also is expected to exhibit a suppressing effect
on the absorption of phosphoric acid.
In the conventional technologies , it has been tried to solve
the problem of taste by use of water-soluble calcium ions. On the
contrary, the present inventors have found that the problem can
be solved by the addition of water-insoluble calcium carbonate or
sparingly water-soluble calcium hydroxide in the solidstates. That
is , various kinds of juice are taken generally with the mouth feel
and taste of the solids contained in fruit or vegetables and on
this occasion, the addition of calcium carbonate or calcium
hydroxide in the solid state can neutralize excessive acidity
without deteriorating the taste. The present invention has been
achieved based on this finding.
Since the potassium content varies depending on the kind of
the original raw material juice as obtained by reaming fruit or
vegetable, the amount of cation exchange resin adapted for the
potassium content of each original raw material juice and contact
time are taken into consideration in order to produce many kinds
of low potassium juice and it has been found that by so doing the
above-described various foods using low potassium juice from which
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a sufficient amount of potassium has been removed, preferably the
amount of potassium has been decreased to less than one-tenth, more
preferably no more than one-twentieth of the amount of potassium
contained in the original raw material juice as a raw material can
be provided.
Further, the present inventors have completed the present
invention having the great feature that has not been attained by
the conventional technologies that the amount of calcium carbonate
can be controlled in accordance with the state of patients suffering
from kidney failure. In other words, the present inventors have
found that the addition of calcium carbonate or calcium hydroxide
in the solid state to juice, which is obtained by sufficiently
depotassifying fruit or vegetable juice and has reduced its taste,
in amounts or necessary for the therapy of patients suffering from
kidney failure can simultaneously solve the problems of taste and
consideration for conditions of various foods for patients
suf f Bring from kidney failure .
Accumulation of phosphoric acid in the body is an important
problem to patients suffering from kidney failure and it has been
an important daily subject to limit the uptake of food containing
phosphoric acid and suppress the absorption of phosphoric acid.
That is, a general doctors' manual in the U. S., The Merck Manual
( 5th Bd. , Merck Sharp & Dohme Research Laboratories , pp 1551-1652 ,
esp. pp 1573 (1987)) describes that in patients suffering from
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kidney failure abnormal metabolisms of calcium ion, phosphate ion,
parathyroid hormone and vitamin D in blood occur, which when left
to stand without any treatment will cause hypocalcemia and
hyperphosphatemia, and that in daily diet therapy for patients
suffering from kidney failure, food containing potassium must be
avoided and calcium carbonate, an absorption suppressor for
phosphoric acid, must be taken in order to avoid deterioration of
hyperphosphatemia.
Therefore , it is reasonable to add calcium carbonate to low
potassium juice obtained by treatment with cation exchange resin
in order to solve such a problem. In fact, in the therapy of
hyperphosphatemia with an absorption suppressor for phosphoric acid,
aluminum hydroxide and aluminum carbonate have been conventionally
used. Currently, to avoid toxicity, calcium carbonate ( 0 . 5 to 1. 5
g/day) is administered orally.
The first aspect of the present invention provides low
potassium juice having an improved taste obtained by treating juice
reamed from fruit and/or vegetable with a cation exchange resin
to decrease the potassium content of original raw material juice
to no more than one-tenth, preferably no more than one-twentieth,
and adding a calcium compound selected from calcium carbonate and
calcium hydroxide in the solid state to the juice.
The second aspect of the present invention provides the low
potassium juice as claimed in claim 1, characterized in that the
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treatment with a cation exchange resin is a column treatment or
batch treatment.
The third aspect of the present invention provides the low
potassium juice as claimed in claim 1, characterized in that the
cation exchange resin is of an H~ form.
The fourth aspect of the present invention provides a method
for producing low potassium juice having an improved taste,
characterized by comprising treating juice reamed from fruit and/or
vegetable with a cation exchange resin to decrease the potassium
content of original raw material juice to no more than one-tenth,
preferably no more than one-twentieth, and adding a calcium compound
selected from calcium carbonate and calcium hydroxide in the solid
state to the juice.
The fifth aspect of the present invention provides the method
for producing low potassium juice as claimed in claim 4,
characterized in that the treatment with a cation exchange resin
is a column treatment or batch treatment.
The sixth aspect of the present invention provides the method
for producing low potassium juice as claimed in claim 5,
characterized in that the cation exchange resin is of an H' form.
The seventh aspect of the present invention provides low
potassium juice having an improved taste obtained by treating juice
reamed from fruit and/or vegetable with a cation exchange resin
to decrease the potassium content of original raw material juice
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to no more than one-tenth, preferably no more than one-twentieth,
adding a calcium compound selected from calcium carbonate and
calcium hydroxide in the solid state to the juice, and adding organic
acid.
The eighth aspect of the present invention provides the low
potassium juice as claimed in claim 7, characterized in that the
organic acid is at least one organic acid selected from the group
consisting of vitamin C, citric acid, malic acid, and lactic acid.
The ninth aspect of the present invention provides the low
potassium juice as claimed in claim 7, characterized in that the
treatment with a cation exchange resin is a column treatment or
batch treatment.
The tenth aspect of the present invention provides the low
potassium juice as claimed in claim 7, characterized in that the
cation exchange resin is of an H' form.
The eleventh aspect of the present invention provides
powdered low potassium juice obtained by treating juice reamed from
fruit and/or vegetable with a cation exchange resin to decrease
the potassium content of original raw material juice to no more
than one-tenth, preferably no more than one-twentieth, adding a
calcium compound selected from calcium carbonate and calcium
hydroxide in the solid state to the juice, adding an excipient,
and subjecting the mixture to freeze-drying treatment.
The twelfth aspect of the present invention provides the
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powdered low potassium juice as claimed in claim 1I , characterized
in that the treatment with a cation exchange resin is a column
treatment or batch treatment.
The thirteenth aspect of the present invention provides the
powdered low potassium juice as claimed in claim 11 , characterized
in that the cation exchange resin is of an H+ form.
The fourteenth aspect of the present invention provides low
potassium juice-containing food, characterized by containing the
low potassium juice as claimed in claim 1 or 7, or powdered low
potassium juice as claimed in claim 11.
The fifteenth aspect of the present invention provides low
potassium juice-containing food as jelly, characterized by
comprising the low potassium juice as claimed in claim 1 or 7 or
powdered low potassium juice as claimed in claim 11, a gelling agent ,
a thickener, and carbohydrates.
The sixteenth aspect of the present invention provides low
potassium juice-containing food as jelly, characterized by hot
filling a heated mixture of food consisting of the low potassium
juice as claimed in claim 1 or 7 or powdered low potassium juice
as claimed in claim 11, a gelling agent, and carbohydrates in a
soft container equipped with a mouthpiece having a cap.
The seventeenth aspect of the present invention provides low
potassium juice-containing food as gummy, characterized by
comprising the low potassium juice as claimed in claim 1 or powdered
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low potassium juice as claimed in claim 11, a gelatin, carbohydrates,
an organic acid, and a flavoring.
The eighteenth aspect of the present invention provides low
potassium juice-containing food as candy, characterized by
comprising the low potassium juice as claimed in claim 1 or 7 or
powdered low potassium juice as claimed in claim 11 , carbohydrates ,
and a flavoring.
The nineteenth aspect of the present invention provides low
potassium juice for patients suffering from kidney failure,
characterized by comprising juice reamed from fruit and/or
vegetable being decreased the potassium content thereof to no more
than one-tenth, preferably no more than one-twentieth and having
0.5 to 20 g/kg of a calcium compound.
The present invention provides low potassium juice for
patients suffering kidney insufficiency, having good taste and
maintaining nutrition balance obtained by treating usual juice
containing potassium, so-called original raw material juice, with
a cation exchange resin to decrease the potassium content of the
original raw material juice to less than one-tenth, preferably no
more than one-twentieth, adding a calcium compound selected from
calcium carbonate and calcium hydroxide in the solid state to the
juice, and optionally adding vitamin C, citric acid, malic acid,
lactic acid, etc., a production method for producing the low
potassium juice, and foods containing the low potassium juice. The
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foods containing low potassium juice include, for example, powdered
juice, nectar, jelly, mousse, jam, pudding, candy, etc.
As described above, specific embodiments of the present
invention includes , ( 1 ) low potassium juice having an improved taste
obtained by treating juice reamed from fruit and/or vegetable with
a cation exchange resin to decrease the potassium content of
original raw material juice to no more than one-tenth, preferably
no more than one-twentieth, and adding a calcium compound selected
from calcium carbonate and calcium hydroxide in the solid state
to the juice, ( 2 ) a method for producing a low potassium juice having
an improved taste, comprising treating juice reamed from fruit
and/or vegetable with a cation exchange resin to decrease the
potassium content of original raw material juice to no more than
one-tenth, preferably no more than one-twentieth, and adding a
calcium compound selected from calcium carbonate and calcium
hydroxide in the solid state to the juice, ( 3 ) low potassium juice
having an improved taste obtained by treating juice reamed from
fruit and/or vegetable with a cation exchange resin to decrease
the potassium content of original raw material juice to no more
than one-tenth, preferably no more than one-twentieth, adding a
calcium compound selected from calcium carbonate and calcium
hydroxide in the solid state to the juice, and adding such organic
acid as vitamin C, citric acid, malic acid, lactic acid and mixture
thereof , ( 4 ) powdered low potassium juice obtained by treating juice
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reamed from fruit and/or vegetable with a cation exchange resin
to decrease the potassium content of original raw material juice
to no more than one-tenth, preferably no more than one-twentieth,
adding a calcium compound selected from calcium carbonate and
calcium hydroxide in the solid state to the juice, adding an
excipient, and subjecting the mixture to freeze-drying treatment,
(5) foods containing the low potassium juice or powdered low
potassium juice, and ( 6 ) low potassium juice for patients suffering
kidney failure, comprising juice reamed from fruit and/or vegetable
and containing 0.5 to 20 g/kg of a calcium compound, and the
potassium content of the juice is decreased to no more than one-tenth,
preferably no more than one-twentieth.
DESCRTPTTON OF PREFERRED EMBODIMENTS
The original raw material juice used in the present invention
includes all the types of juice such as juice obtained by reaming
a vegetable, juice obtained by reaming a fruit, and juice obtained
by mixing the juices. As for preliminarily concentrated juice, it
can be diluted to the concentration of the original raw material
juice or the concentration which enables ion exchange treatment
as described hereinbelow.
The cation exchange resin used in the present invention may
be any of commercially available cation exchange resins , which are
adjusted to H+ form by a conventional method before use. The
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treatment with cation exchange resin may be a batch process or a
column process . When the treatment is carried out in a batch process ,
about 20 to 1,000 g of cation exchange resin which is dried per
1,000 g of raw material juice is provided and added it to the raw
material juice, followed by stirring for 20 minutes or more, usually
for about 30 minutes and filtration.
On the other hand, when the treatment is carried out in a column
process , a column packed with about 85 to 500 in weight ( g ) or volume
(mL) of cation exchange resin per 1,000 g of raw material juice
is provided and the raw material juice is charged therein and allowed
to pass therethrough over 0.5 to 2.0 hours.
Thus , the treatment with cation exchange resin can reduce the
potassium content in the raw material juice to one-tenth or less
compared with the original content. The potassium content may be
reduced to one-twentieth or less compared with the original content
depending on the kind of raw material juice, amount of the cation
exchange resin used, the contact time i n which the juice contacts
the cation exchange resin and other factors . In view of productivity
and efficiency of ion exchange, the treatment by a column process
is preferred.
Further, low potassium juice with improved taste, acidity,
and nutrition can be produced by adding to the juice, after the
treatment with cation exchange resin to lower the content of
potassium, a calcium compound selected from the group consisting
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of calcium carbonate and calcium hydroxide in the solid state in
an amount of 0.5 to 20 g/kg, preferably to such an extent that the
pH of the raw material juice is not returned completely to keep
a preservation stability and a taste like the original raw material
juice, and if necessary adding vitamin C, citric acid, malic acid,
lactic acid, and the like.
Depending on the balance between phosphate ion concentration
and potassium ion concentration in blood, patients suffering from
kidney failure can take 0.5 to 1.5 g a day of calcium carbonate.
The low potassium juice provided by the present invention may,
if necessary, be blended, within the range where no adverse effect
to the function of kidney is observed, with various vitamins,
carbohydrates, dyestuffs, flavors to impart variation in taste.
Of course, the juice can be provided as it is as a beverage. However,
if necessary, it may be subjected to preparing into powder or
agglomerates in addition to the steps of concentration, drying,
and agglomeration. The product in the form of powder or agglomerates
can be taken as it is or returned to a liquid state by addition
of water, or added to other foods.
Hereafter, the present invention will be described in detail
by means of examples . However, the present invention is not limited
thereto.
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In the examples, the cation exchange resin used was
commercially available cation exchange resin, Dowex 50W-X4 or SK1B
(MITSUBISHI DIA ION Co., LTD.) preliminarily adjusted by the
following procedures.
That is , purified water was added to 500 g of the cation
exchange resin and the mixture was stirred to sufficiently wash
the resin. To the drained resin was added 500 mL of ethanol and
the mixture was stirred for 30 minutes. Then, ethanol was removed
by filtration. After the washing operation with ethanol was repeated
3 times, ethanol was changed to purified water to conduct washing.
To the water-washed resin was added 500 mL of 1M sodium hydroxide
solution and the mixture was stirred for 30 minutes. Thereafter,
the resin was recovered by filtration. After the operation of the
treatment with sodium hydroxide solution was repeated 5 times , the
resin was washed with water, until the washing became neutral.
Then , the washed resin was packed in a column , through which
was passed 2 , 500 mL of 3 M hydrochloric acid solution and further
the column was washed with water until the washing became neutral.
After the above operations , the resin as it was or after sufficiently
drying it by suction filtration, served as H' form cation exchange
resin.
The amounts of ethanol, purified water, 1M sodium hydroxide
solution, and washing, etc. may be selected appropriately along
with an increase or decrease of the amount of cation exchange resin
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used in accordance with the amount of the original raw material
juice.
Example 1
Production method in a batch process
The dried H~ form cation exchange resin in the amount shown
in Table 1 was added in 1, 000 mZ of each of commercially available
100% orange juice, 100% apple juice, 100% grape fruit juice, and
100% grape juice as a raw material juice and the mixture was stirred
for 30 minutes to adsorb potassium. Thereafter, calcium carbonate
in the solid state in the amount shown in Table 1 was added to each
juice after filtration. Further, to each juice was further added
vitamin C such that its concentration was equivalent to that of
the juice before the treatment as measured by a titration method.
The mixture was stirred to dissolve the additives thereby producing
low potassium juice, final product.
The concentration of potassium in juice was measured by using
Automated Electrolyte Analyzer EA05 (A and T) and the pH of juice
was measured by using commercially available pH meter before and
after the treatment with the cation exchange resin without the
addition of vitamin C. The results are shown in Table 1.
As can be seen from the results, juice having a potassium
content reduced to one-tenth or one-twentieth of the original one
were produced.
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Table 1 Results of treatment of various kinds of juice with ion
exchange resin
Grapefruit
Orange juicel Apple juice Grape juice
juice
Raw material 1,000 ~ 1,000 1,000 1,000
juice
(mL)
i
Amount of 50 40 50 25
resin used
(g)
Concent- Before
48'0 25.7 38.~ 7.6
ration of treatment ~j
potassium Afte
r 2'S 0-8 2.1 0.6
(mmol/L) treatment
Potassium
removal 0.950 0.962 0.947 0.923
ratio
After 3.81 4.05 3.30 3.00
treatment
p
Before
2.18 2.28 2.02 2.07
treatment
Amount of
calcium
carbonate 2.61 2.08 3.65 1.56
added
(g/L)
Test 1
200 mL of low potassium orange juice having a potassium
concentration of 2.5 mmol/L prepared by the method in accordance
with that in Example 1 was given to each of patients suffering from
kidney failure who were receiving the same dialysis therapy once
at the time of dialysis and once at non-dialysis time . The change
in blood potassium level in the patients before and after the uptake
was measured using Automated Electrolyte Analyzer EA05 (A and T) .
Table 2 shows the measured values obtained.
From the results , it revealed that the low potassium orange
juice produced by the present invention caused no change in blood
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potassium level when taken by patients suffering from kidney failure
so that it can be given to the patients who suffer from kidney failure
saf ely .
Table 2 Change in blood potassium level when low potassium
orange juice is given
Blood potassium
level (mmol/L)
I Patient Upon dialysis
Upon non-dialysis
1 hour before 1 hour after 1 hour before 1 hour after
uptake uptake uptake uptake
A 5.5 3.5 5.5 5.5
B 4.9 4.3 4.9 4.9
C 4.5 3.3 4.5 4.5
Example 2
Production method in a batch process
To 1,000 mL of commercially available green-yellow vegetable
juice (raw material: celery, parsley, watercress, cabbage, radish,
spinach, or trefoil) was added 700 g of cation exchange resin and
the treatment with the cation exchange resin was carried out in
the same manner as in Example 1 to obtain the vegetable juice from
which potassium was removed by adsorption.
Then, to the vegetable juice was added calcium carbonate in
the solid state in the amount shown in Table 3 and thereafter vitamin
C was added to the vegetable juice such that the concentration was
equivalent to that before the treatment as measured by a titration
method. The mixture was stirred to dissolve the additives thereby
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producing low potassium juice, final product.
Before the treatment with the cation exchange resin and before
the addition of vitamin C, the concentration of potassium in juice
and the pH of juice were measured in the same manner as in Example
1. The results are shown in Table 3 . As can be seen from the results ,
green-yellow vegetable juice having a potassium content reduced
to one-twentieth of the original one were produced.
Table 3 Results of treatment of vegetable juice with ion
exchange resin
Amount of juice used(mL) 1,000
~
Amount of resin used 700
(g)
~
Concentration Before treatment 128.7
of potassium
(mmol/L) After treatment 6.2
Potassium removal 0.952
ratio ~
pH
After 4.01
treatment 0.99 I
~
Before
treatment
~,
Amount of calcium 13.3 I
carbonate added
(g/L)j
Example 3
Production method in a column process
First , 2 , 000 kg of deionized water was added to 500 kg of 5-fold
concentrated orange juice and the mixture was well stirred and mixed
and depulping treatment was carried out using a centrifuge . 1 , 250
kg of the depulped 1000 orange juice was collected and weighed.
Moreover, 1, 080 kg of deionized water was added to 180 kg of
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7-fold concentrated clarified apple juice and the mixture was well
stirred and mixed to prepare 1000 apple juice.
Further, 85 kg of 6-fold concentrated carrot squeezed juice,
7 kg of 10-fold concentrated tomato squeezed juice, 10 kg of 6-fold
concentrated spinach squeezed juice, 190 kg of above 1000 orange
juice, 43 kg of 7-fold concentrated clarified apple juice, 31 kg
of 4-fold concentrated turbid apple juice and 884 kg of deionized
water were stirred and mixed well to prepare mixed juice.
The prepared juice used as raw materials were passed through
a cylindrical column of 2 m in height and 55 cm in diameter packed
with 303 kg of dry H type cation exchange resin SK1B (Mitsubishi
Dia Ion) from an upper part thereof over 1 hour, and then solid
calcium carbonate were added as they were in the amount shown in
Table 4 to produce low potassium juice, final products.
Before and after the treatment with the cation exchange resin,
the concentration of potassium in juice were measured using
Polarized Zeeman atomic-absorption spectrometer Z-5300 (Hitachi,
Ltd.). The results are shown in Table 4.
As can be seen from the results , low potassium juices having
a potassium content reduced to one-hundredth or less of the original
one were produced.
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Table 4 Results of ion exchange resin treatment of various raw
material juices in a column process
Orange juice Apple juice Mixedjuic
Raw material 1,250 1,250
juice (kg)
1,250
Amount of resin 303 303
used (kg) 303
Concentration Before g0.5 29.7 59.5
of potassium treatment
(mmol/kg) After
0.16 0.05 0.15
treatment
Potassium removal 0.998 0.998
ratio 0.998
Before 3. g0 3.68 4.29
treatment
p
Af ter
1.97 2.30 1.79
treatment
After addition
of calcium
3.07 3.22 3.52
carbonate
Addition amount 0.8 2.5
of calcium
2.7
Carbonate (g/kg)
Test 2
For various low potassium juice prepared during the steps in
Example 3 or as final products, organoleptic tests were carried
out before and after addition of calcium carbonate . The tests were
carried out by a panel of specialists ( 20 persons ) who had excellent
taste discrimination ability. Hedonic scores were as follows.
+2: taste was felt strongly.
+1: taste was felt fairly.
0: unclear whether or not taste was felt.
-1: taste was felt not so much.
-2: almost no taste was felt.
The results expressed by average values of the hedonic scores
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obtained are shown in Table 5.
Table 5 Sensory evaluation of taste before and after addition
of calcium carbonate
Kind of juice Before addition After addition
Orange juice -1.4 +1.6
Apple juice -1.8 +1.7
Mixed juice -1.7 +1.4
Example 4
To 1,250 kg of low potassium orange juice (pH 2.05) prepared
in accordance with the method described in Example 3 except that
no calcium carbonate was added was added 2.8 kg of solid calcium
hydroxide as it was to produce low potassium orange juice (pH 3. 25 ) ,
final product.
The produced low potassium orange juice were evaluated in the
same manner as the special panel described in Test 2. The result
confirmed that the juice had similar taste to that of the low
potassium orange juice to which was added calcium carbonate as
described in Example 3.
Example 5
To 28.6 kg of 7-fold concentrated transparent apple juice and
200.0 kg of 4-fold concentrated turbid apple juice was added 771.4
kg of deionized water. The mixture was well stirred and mixed to
prepare raw material apple juice.
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The raw material apple juice was measured of the potassium
content in 1 g by the method of Example 3, which revealed to be
1.10 mg. Subsequently, the column type ion exchange resin
treatment was conducted in the same manner as in Example 3 to obtain
low potassium apple juice and the amount of potassium in 1 g of
the juice was measured by the method of Example 3. As a result,
a value of 0.05 mg was obtained.
To 10 kg of the low potassium apple juice were added 1 kg of
DE 8 dextrin as an excipient and 10.0 g of calcium carbonate and
mixed to obtain low potassium juice containing calcium carbonate.
The juice was charged in a tray made of stainless steel to a thickness
of 1 cm. The tray was subjected to quick freezing treatment at -25°C
for 8 hours and then to ordinary freeze-drying at 26.7 Pa to obtain
low potassium powdered juice.
Comparative Example 1
For comparison, in the same manner as in Example 5, dextrin
was added to the raw material apple juice obtained in the same manner
as in Example 5 without conducting any ion exchange resin treatment
and mixed. The mixture was charged in a tray made of stainless steel
to a thickness of 1 cm. The tray was subjected to quick freezing
treatment at -25°C for 8 hours and then to ordinary freeze-drying
at 26.7 Pa to obtain ordinary powdered juice.
Test 3
The low potassium powdered juice obtained in Example 5 and
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the powdered juice obtained in Comparative Example 1 were each
reconstituted to natural juice concentration corresponding to 100%
and taste tests were conducted by a panel of 20 panelists by
alternative selection ratio in paired comparison test at a
significance level of 5 % . As a result , those who preferred the low
potassium powdered juice were 40 % and those who preferred ordinary
powdered juice were 60% so that the results of test indicated no
significant difference.
Example 6
6.83 kg of 6-fold concentrated carrot squeezed juice, 0.5 kg
of 10-fold concentrated tomato squeezed juice, 0.83 kg of 6-fold
concentrated spinach squeezed juice, 15 kg of 100% orange juice
obtained in Example 3 , 3 . 43 kg of 7-fold concentrated transparent
apple juice, 2.5 kg of 4-fold concentrated turbid apple juice, and
55. 15 kg of deionized water were well stirred and mixed to prepare
ordinary mixed juice. Subsequently, column-type ion exchange
resin treatment was performed in the same manner as in Example 3
to obtain low potassium mixed juice. The low potassium mixed juice
was concentrated to Bx 13.3 using a vacuum concentrator.
Separately, a gelling agent mixture consisting of 31.5% by
weight of agar, 5 % by weight of xanthan gum, 5 % by weight of locust
bean gum, and 58.5% by weight of glucose and a thickener mixture
consisting of 40 % by weight of xanthan gum, 40 % by weight of locust
bean gum, and 20% by weight of glucose were prepared. Then, 514.5
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g of stock water was added to 99 g of sugar, 8 g of the gelling
agent mixture, and 0.4 g of the thickener mixture and the mixture
was well mixed and dispersed and then dissolved at 90°C and mixed
to prepare a sugar solution.
On the other hand, to 376 g of the low potassium mixed juice
were added 0.24 g of solid calcium carbonate and 1. 6 g of a flavoring
and further the whole amount of the sugar solution, followed by
heating at 60°C. Then, 80 g aliquots were filled in plastic
containers and the openings were sealed with an appropriate wrapping
material and subsequently pasteurized by a conventional method to
obtain jelly.
Comparative Example 2
Citric acid (1.5 g) was added to 376 g of ordinary mixed juice
obtained by a method similar to that described in Example 6 without
performing any ion exchange treatment with ion exchange resin in
order to make the pH equivalent to that of the product in Example
6. Further, 1.6 g of a flavoring was added and the same amount of
the sugar solution as in Example 6 was added, followed by heating
at 60°C. Thereafter, 80 g aliquots of the mixture were filled in
plastic containers and the openings were sealed with an appropriate
wrapping material and subsequently pasteurized by a conventional
method to obtain ordinary jelly.
Test 4
The amount of potassium in 100 g of the low potassium mixed
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juice containing jelly obtained in Example 6 was measured by the
method described in Example 3 and the result of 6 . 46 mg was obtained.
On the other hand, the amount of potassium in 100 g of ordinary
jelly containing the ordinary mixed juice obtained in Comparative
Example 2 was 132.09 mg.
Then, the low potassium mixed juice containing jelly obtained
in Example 6 and the ordinary jelly composed of ordinary mixed juice
obtained in Comparative Example 2 were subjected to taste tests
by a panel of 20 panelists by alternative selection ratio in a paired
comparison test at a significance level of 5 0 . As a result , those
who preferred the low potassium mixed juice containing jelly were
45~ and those who preferred the ordinary jelly composed of ordinary
mixed juice were 55~ so that the results of test indicated no
significant difference.
Example 7
To 28.6 kg of 7-fold concentrated clarified apple juice and
200.0 kg of 4-fold concentrated turbid apple juice was added 771.6
kg of deionized water. The mixture was well stirred and mixed to
prepare raw material apple juice. Subsequently, the column type
ion exchange resin treatment was conducted in the same manner as
in Example 3 to obtain low potassium apple juice . The low potassium
apple juice was concentrated to Bx 13 . 3 using a vacuum concentrator.
Separately, a gelling agent mixture consisting of 31.5% by
weight of agar, 5 o by weight of xanthan gum, 5~ by weight of locust
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bean gum, and 58.50 by weight of glucose and a thickener mixture
consisting of 40~ by weight of xanthan gum, 40% by weight of locust
bean gum, and 20~ by weight of glucose were prepared.
Then, 85 g of sucrose, 9 g of the gelling agent mixture, and
0.4 g of the thickener mixture, and 531.3 g of stock water were
well mixed and dispersed and then dissolved at 90°C and mixed to
prepare a sugar solution. On the other hand, to 375 g of the low
potassium apple juice were added 0.35 g of calcium carbonate and
1.0 g of a flavoring and further the whole amount of the sugar
solution, followed by heating at 92°C. Then, 150 g aliquots were
hot filled and sealed in soft containers each equipped with a
mouthpiece having a cap to obtain jelly. The pH of the product was
3.8.
Comparative Example 3
A flavoring ( 1 . 0 g) was added to 375 g of ordinary apple juice
obtained by a method similar to that described in Example 7 except
that treatment with ion exchange resin was not performed and the
same amount as in Example 7 of the sugar solution prepared in the
same manner as in Example 7 was added, followed by heating at 92°C.
Then, 150 g aliquots were hot filled and sealed in soft containers
each equipped with a mouthpiece having a cap to obtain jelly. The
pH of the product was also 3.8.
Test 5
The amount of potassium in 100 g of the low potassium apple
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juice containing jelly obtained in Example 7 was measured by the
method described in Example 3 and the result of 5. 08 mg was obtained.
On the other hand, the amount of potassium in 100 g of ordinary
jelly composed of the ordinary apple juice obtained in Comparative
Example 3 was 57.84 mg.
Concerning the calcium content in each produc t , it was 13 mg
for the low potassium apple juice containing jelly obtained in
Example 7 and 3 mg for the ordinary jelly composed of the ordinary
apple juice obtained in Comparative Example 3.
Then, the low potassium apple juice containing jelly obtained
in Example 7 and the ordinary jelly composed of ordinary apple juice
obtained in Comparative Example 3 were subjected to taste tests
by a panel of 20 panelists by alternative selection ratio at a
significance level of 5 0 . As a result , those who preferred the low
potassium apple juice containing jelly were 50o and those who
preferred the ordinary jelly composed of ordinary apple juice were
50~ so that the results of test indicated no significant difference.
Further, ordinary fruit juice jellies commercially available
under three different brands were measured of the amount of
potassium by the method described in Example 3 and as a result 54.8
mg, 47.3 mg, and 62.3 mg per 100 g of the content were obtained.
Example 8
The low potassium apple juice obtained in Example 5 was
concentrated to Bx 13 . 3 by a vacuum concentrator. 0 . 035 o by weight
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of solid calcium carbonate was added to the juice.
In a formulation of 2.9% by weight of the solid calcium
carbonate containing juice, 48.5% by weight of sucrose, 48.50 by
weight of high maltose corn syrup ( containing 25 % by weight of water ) ,
and O.lo by weight of a flavoring, sucrose and high maltose corn
syrup and water as much as one-third of sucrose were mixed and heated
to 160°C and then cooled to 150°C. Then, the flavoring and the
solid
calcium carbonate containing juice obtained as above were added
thereto and the mixture was mixed before it was molded to obtain
candy.
The potassium content of the candy was measured by the method
described in Example 3 to be 0 . 002 mg% . Measurement of the calcium
content using the analyzer in Example 3 resulted in 1.143 mgo.
Comparative Example 4
The raw material apple juice in Example 5 which was not
subjected to the treatment with ion exchange resin was concentrated
to Bx 13.3 by a vacuum concentrator. Using the concentrated apple
juice of Bx 13.3, ordinary candy was obtained in the same manner
as in Example 8 without adding any calcium carbonate.
The potassium content of the candy measured by the method
described in Example 3 was 4. 505 mgo . Further, the calcium content
measured using the analyzer in Example 3 was 0.075 mgo.
Test 6
The candy obtained in Example 8 and ordinary candy composed
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of ordinary apple juice obtained in Comparative Example 4 were
subjected to taste tests by a panel of 20 panelists by alternative
selection ratio in paired comparison test at a significance level
of 50. As a result, those who preferred the candy of Example 8 were
450 and those who preferred the ordinary candy were 550 so that
the results of test indicated no significant difference.
Example 9
In a formulation of 5.40 by weight of the low potassium
powdered juice obtained in Example 5 , 47 . 0 % by weight of sucrose ,
47 . 0 o by weight of high maltose corn syrup ( containing 25 o by weight
of water), sucrose, high maltose corn syrup, and water as much as
one-third of sucrose were mixed and heated to 160°C and then cooled
to 150°C. Then, the low potassium powdered juice, 0.1~ by weight
of a flavoring, 0.50 by weight of citric acid were added, mixed
and molded to obtain candy.
The potassium content of the candy measured by the method
described in Example 3 was 0.15 mgo . Further, the calcium content
measured using the analyzer in Example 3 was 12 mgt.
Example 10
The calcium carbonate containing low potassium apple juice
obtained in Example 5 was concentrated to Bx 14.4 by a vacuum
concentrator. In a formulation of 77. 040 o by weight of the juice,
28 . 240 % by weight of sucrose, 5 . 780 o by weight of powdered sorbitol,
49.9060 by weight of acid converted glucose syrup (containing 250
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by weight of water) , 6.437 by weight of gelatin, 1. 134 o by weight
of citric acid, 0.341% by weight of malic acid, 0.306% by weight
of dyestuff, 0.144% by weight of a flavoring, sucrose, sorbitol,
glucose syrup, and water as much as one-third of sucrose were mixed
and heated to 125°C to obtain a boiled sugar solution.
On the other hand, gelatin was swollen with 1.5 fold volume
of water. Then, the concentrated calcium carbonate containing low
potassium apple juice, the boiled sugar solution, and the swollen
gelatin were mixed. Finally, citric acid, malic acid, dyestuff,
and a flavoring were mixed to obtain a gummy base of Bx79.
Next, the gummy base was cast in a starch mold and left to
stand for a whole day and night to obtain molded gummy of Bx 82.
The potassium content of the product measured by the method
described in Example 3 was 0.8 mgt and the calcium content measured
using the analyzer in Example 3 was 6.3 mgo.
Comparative Example 5
The raw material apple juice in Comparative Example 1 which
was not subjected to the treatment with ion exchange resin was
concentrated to Bx 14.4 by a vacuum concentrator. Using the
concentrated apple juice of Bx 14.4, ordinary gummy was obtained
in the same manner as in Example 9.
The potassium content of the product measured by the method
described in Example 3 was 8.65 mgo . Further, the calcium content
measured using the analyzer in Example 3 was 3.3 mg%.
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Test 7
The gummy obtained in Example 10 and ordinary gummy obtained
in Comparative Example 5 were subjected to taste tests by a panel
of 20 panelists by alternative selection ratio in paired comparison
test at a significance level of 5 % . As a result , those who preferred
the gummy of Example 10 were 40 o and those who preferred the ordinary
gummy were 60 a so that the results of test indicated no significant
dif f erence .
INDUSTRIAL APPLICABILITY
According to the present invention, there are provided low
potassium juice of which the potassium content has been decreased
to one-tenth or less , preferably one-twentieth or less as compared
with the natural content and a method for producing the juice as
well as food containing the juice.
The low potassium juice of the present invention has improved
taste by addition of calcium carbonate or calcium hydroxide in the
solid state.
The powdered juice, jelly, candy, gummy, etc. produced by use
of the low potassium juice have equivalent tastes to that of ordinary
food.
The low potassium juice provided by the present invention are
suitable for patients suffering from a decrease in kidney function,
such as kidney failure, who are subjected to restriction on the
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uptake of potassium. Further, the low potassium juice of the present
invention and food containing it can be provided for the prevention
of hyperphosphatemia in patients suffering from kidney failure.
38
