Note: Descriptions are shown in the official language in which they were submitted.
-l- 1339396
PROCESS FOR PRODUCING KONJAK JELLY
The present invention relates to a process for
producing a konjak (a substance made from the starch of
the corms of the plant Amophorphallus Rivievi) jelly which
is suitable as a method of diversifying the utilization of
konjak, for example, by adding it to various kinds of food
with a view to improving their flavor or other properties,
or to various kinds of diet food for calorie control
purposes.
Although it has been utilized as a food from ancient
times, konjak has recently attracted special interest and
has been put in the spotlight because of its non-calorie
properties and i~s usefulness as dietary fiber.
However, konjak is in most cases used in the form
of a slab or the like, in which shape it is usually eaten,
so that konjak has not yet been satisfactorily utilized as
a processed food material which may be added to a food in
order to give it a unique flavor or improve its properties,
or which may be utilized as a binder or for calorie control
purposes.
The reason for this may be attributed to the slow
development of a technique by which a konjak raw material,
for example, konjak flour, may be formed into good quality
processed food materials or food additives.
More specifically, according to z typical conven-
tional process for producing konjak, 900 to 1200 liters
of water is added to about 30 kg of konjak flour, allowing
the latter to swell and thus preparing konjak paste, after
which lime is added to and mixed with the konjak paste in an
amount of 3 to 6% with respect to the amount of konjak flour.
Then, the mixture is placed in â container, forming
frame or the like and heated at about 80~C for about 60
minutes to thereby obtain a piece of konjak. This method
has been practiced for many years.
Accordingly, if one is to use konjak flour as a food
material for addition to another processed food or the like,
it is conventional practice to add konjak flour in the form
1339396
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of a finely-ground powder with a view to facilitating disso-
lution, or in the form of konjak paste which is formed by
making konjak flour swell by addition of water or by mixing
lime with konjak flour.
These conventional methods suffer, however, from the
following problems. Namely, mannan originated from konjak
does not completely set to gel even in the final-product
stage, and the pasty state that is retained is rather
undesirable. The smell of slaked lime which is used as a
solidification agent for konjak paste unfavorably remains.
Since the pH of the product inclines toward the alkali side,
the taste may be adversely affected.
Accordingly, although it is desired to use a larger
amount of konjak in order to improve the properties of food
or provide for calorie control, the amount of konjak which
is usable is to a substantial extent limited.
In these circumstances, the present inventors made
exhaustive studies in order to develop food additives and
processed food materials that could be produced with konjak
and which are free from the above-described problems, as
well as eliminating any risk that the ingredients which
constitute the konjak may separate from each other or that
water may be irreversibly liberated from solid matter during
storage over long periods of time.
As a result, the present inventors have succeeded in
processing a konjak raw material to produce a konjak mate-
rial in the form of jelly which may conveniently be added
to food or be processed, thus attaining the above-described
object.
~,:
-2a- 1339396
1 The invention in its broadest aspect provides a
process for producing a konjak jelly comprising the steps
of: adding water to konjak flour to cause the latter to
swell and dissolve in the former, and mixing the resulting
paste with a basic amino acid, a base, or a mixture thereof;
or adding to konjak flour water which has been mixed with a
basic amino acid, a base, or a mixture thereof in advance;
or mixing konjak flour with a basic amino acid, a base, or a
mixture thereof in advance, and adding water to the
resulting mixture to cause the latter to swell and dissolve
in the former; and heating the resulting konjak paste under
alkaline conditions and then cooling it.
More specifically, the present invention provides a
process for producing a konjak jelly comprising the steps
of: adding water to konjak flour to cause the latter to
swell and dissolve in the former, and mixing the resulting
paste with a basic amino acid, a basic salt, or a mixture
thereof; or adding to konjak flour water which has been
mixed with a basic amino acid, a basic salt, or a mixture
thereof in advance; or mixing konjak flour with a basic
amino acid, a basic salt, or a mixture thereof in advance,
and adding water to the resulting mixture to cause the
latter to swell and dissolve in the former; and heating the
resulting konjak paste under alkaline conditions and then
cooling it.
In a preferred aspect, the invention provides a
process for producing a thermally irreversible thickened gel
which is blendable with other food products, said process
comprising the steps of (a) forming a konjak paste by mixing
components consisting essentially of konjak flour, an amount
sufficient of water to cause the konjak flour to swell and
dissolve, and a basic amino acid, a basic salt, or mixture
thereof; (b) heating said konjak paste under weak alkaline
conditions at a temperature and time sufficient to begin the
setting of said konjak paste, said temperature being about
60~C. or more, to thereby begin setting of said konjak
paste; and (c) then, prior to completion of setting of said
B
~3~ 1339396
.
1 heated konjak paste, rapidly cooling the heated paste and
thus stopping said setting prior to essential completion of
said setting of said konjak paste into a firm gel.
The konjak jelly according to the present invention
is different from the so-called konjak paste which is formed
by allowing konjak flour to swell in water, and is also
different from the konjak gel which is obtained by adding an
alkali to konjak paste and heating the mixture. The konjak
jelly of the present invention is midway between konjak
paste and gel from the viewpoint of properties.
Accordingly, the konjak jelly of the present inven-
tion possesses viscosity and hardness at appropriate levels
and may therefore be mixed with any kind of food in desired
proportions.
Unlike mere konjak paste, the konjak jelly according
to the present invention causes gelation when heated during
the processing of a food containing it and sets completely.
It should be noted that there is a ~reversible-state
konjak~ disclosed in Japanese Patent Public Disclosure
No. 58-116651 (1983) which is likely to be confused with the
konjak jelly of the present invention. However, the prior
art is a form of konjak which reversibly changes from a
liquid state to a coagulated state and vice verse in accord-
ance with the degree of cooling and heating applied, and
therefore it is clearly different in terms of properties
from the konjak jelly of the present invention which is in
the jelly state irrespective of whether it is cooled or
heated.
The following is a description of the process for
producing the konjak jelly according to the present
invention.
Water is first added to konjak flour in an amount
equivalent to 20 to 40 times the amount of the latter,
thereby causing the konjak flour to swell and dissolve in
the water and thus obtaining konjak paste. Then, a basic
amino acid, a basic salt, or a mixture thereof is added to
and intimately mixed with the konjak paste. Alternatively,
1339396
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a basic amino acid, a basic salt, or a mixture thereof is
first mixed with an amount of water equivalent to 20 to 40
times the amount of konjak flour used, and then the konjak
flour is allowed to swell and dissolve in the solution.
5 According to still another procedure, konjak flour is first
mixed with a basic amino acid, a basic salt, or a mixture
thereof, and then an amount of water which is 20 to 40 times
the amount of konjak flour is added to and mixed with the
resulting mixture, thereby allowing the konjak flour to
10 swell and dissolve in the mixture. In all three procedures,
the konjak paste thus prepared is heated under alkaline
conditions and then cooled to thereby obtain the desired
konjak jelly.
It should be noted that the temperature and duration
15 Gf the heat treatment are adjusted i~ accordance with the
concentration and pH of the salt used and the desired prop-
erties of the konjak jelly to be obtained. When the pH of
the konjak paste is relatively high, the heating time is set
so as to be relatively short, whereas, when the pH of the
20 paste is relatively low, the heating time is set so as to be
relatively long.
The konjak jelly according to the present invention
must be heated under alkaline conditions. It is preferable
to carry out the heat treatment with the pH of the konjak
25 paste adjusted so that the pH of the jelly obtained after
cooling is in the range of from 8.0 to 10.5, preferably from
8.2 to 10Ø
In this case, it is preferable to select a combina-
tion of heating conditions such that the temperature is from
60 to 95~C and the heating time is from 5 to 210 minutes.
It should be noted that a desirable combination of
pH, temperature and heating time is preferably selected so
that the pH of the jelly obtained after cooling is in the
range of from 8.0 to 10.5, preferably from 8.2 to 10.0, and
it is preferable to determine optimal combination conditions
for these factors in advance by carrying out preliminary
experiments.
The heat treatment used in the present invention is
1339~96
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completed before the konjak paste sets. If the heating
conditions exceed the upper limit of the optimal range, the
konjak paste sets to a gel and loses its mixability with
other ingredients, which is one of the advantageous features
of the konjak jelly according to the present invention.
On the other hand, if the heating conditions are lower than
the lower limit of the optimal range, the paste cannot set
to a gel when the konjak paste is reheated, but remains in
the pasty state. This results in a food material that is
nothing more than a konjak paste swelling in water.
Once the konjak paste which has been appropriately
heated, it must be cooled quickly to stop the reaction.
If this oper2tion is omitted, the paste undesirably becomes
a gel.
The pH of the konjak jelly thus obtained is in the
range of from 8.0 to 10.5, preferably in the range of from
8.2 to 10Ø A pH value in excess of 10.5 results in an
ordinary type of konjak which is difficult to mix with other
foods. A p~ value of less than 8.0 is unfavorable because,
when such a konjak jelly is mixed with other foods, the
jelly remains in the pasty state and will not solidify,
which degrades the commercial value of the resulting food
product.
As described above, the konjak jelly of the present
invention has different properties from those of the afore-
mentioned reversible-state konjak (see Japanese Patent
Public Disclosure No. 58-116651) although both products are
formed by carrying out similar procedures. This is partly
attributable to the difference in the heating conditions.
More specifically, it is clear that the reversible-
state konjak is gelled or coagulated at 80~C, and the
difference in the properties arises from the absence of
a cooling process in the procedure.
As described above, the pH of the konjak jelly of the
present invention during the production process is adjusted
so that the pH of the resulting jelly is in the range of
from 8 to 10.5. In other words, the konjak material is
processed within a lower pH region than in the case of the
1339396
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process for producing ordinary konjak. Thus, the process
according to the present invention is also different from
the conventional konjak production process. Although
ordinary konjak can also be produced in the pH region of
from 9.5 to 10.0 by appropriately setting the heating and
cooling conditions, in the present invention the heating
conditions are set at lower levels than in the case of the
ordinary konjak production process. The heating is stopped
before the konjak paste sets to gel, and the heated konjak
paste is immediately cooled to obtain a konjak jelly.
As for the konjak raw material to be employed in the
present invention, it is possible to use any of the follow-
ing materials, that is, konjak, flour obtained by drying and
grinding konjak, and refined konjak flour.
Examples of basic amino acids which may usually
be employed in the present invention include arginine,
histidine, lysine, citrulline and ornithine. These basic
amino acids may be employed alone or in combination in the
form of a mixture. Particularly preferable basic amino
acids are arginine and lysine.
The amount of a basic amino acid used is preferably
from 1.25 to 15% by weight with respect to the weight of
konjak flour used.
Employment of a basic amino acid enables utilization
of the advantage offered by basic amino acids in that they
have high pH-buffering power whereby it is possible to
stabilize the pH of the konjak paste and obtain a konjak
jelly having stable quality. In addition, it is advanta-
geously possible to obtain a tasty konjak jelly which is
free from alkaline flavor even though it is in fact alkaline.
Examples of basic substances which may be employed
in the present invention usually include organic acid salts
such as sodium citrate, sodium tartrate, sodium malate,
sodium acetate, sodium lactate and sodium succinate, phos-
phates such as sodium polyphosphate, sodium pyrophosphate,sodium metaphosphate, di- or tri-sodium phosphate, potassium
polyphosphate, potassium pyrophosphate, potassium metaphos-
phate, and di- or tri-potassium phosphate, carbonates such
1~33~396
as sodium carbonate, sodium hydrogencarbonate, potassium
carbonate, calcium carbonate, and magnesium carbonate,
sulfates such as potassium sulfate, sodium sulfate, calcium
sulfate, and magnesium sulfate, sodium hydroxide, and potas-
sium hydroxide. As will be clear from these examples, anybasic edible salt may be employed as a basic salt in the
present invention.
It should be noted that in order to provide a buffer
effect it is possible to employ an acid or an acid salt in
combination with a basic substance such that the pH of the
combination is eventually on the alkali side. Examples of
acids or acid salts which may be employed in combination
with a basic substance are citric acid, tartaric ac-d, mzlic
acid, acetic acid, lactic acid, phosphoric acid, monosodi~m
phosphate, and monopotassium phosphate. The amount or acid
or acid salt used is preferably from 0.01 to 5% by weignt
with respect to the weight of konjak flour used.
In the present invention, employment of a basic amino
acid and basic salt in combination enables effective combi-
nation of the characteristics of basic amino acids, whichhave high pH-buffering power and therefore enable stabili-
zation of the pH value but cause difficulties in setting a
desired pH value, and the characteristics of basic salts,
which are such that it is possible to adjust the pH value as
desired by selection of an appropriate substance even though
the pH-buffering power of basic salts is relatively low.
Thus, it is possible to facilitate the p~ setting operation,
suppress fluctuations in pH due to the raw material and
water used, and produce a uniform konjak jelly.
The konjak jelly according to the present invention
has the following advantages. It is possible to add this
konjak jelly to various kinds of food for calorie control
purposes. The konjak jelly may be added to processed marine
foods and processed meat foods to improve the taste, flavor,
water holding capacity, etc., and may also be added to
noodles such as Chinese noodles and wheat vermicelli to
improve their flavor and other properties or to be utilized
as a binder therefor. Further, the konjak jelly may be
1339396
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added to dough for bread or cookies to improve their flavor,
expanding characteristics and other properties.
Further, the konjak jelly may be used for jelly
foods, for example, jam and pastry, by adding sweetening,
spices or the like thereto.
Examples
The following Examples are provided for the purpose
of further illustrating the present invention but are not to
be construed as limiting.
Example 1
One hundred liters of water having 0.35 kg of
L-arginine dissolved therein was added to 4 kg of refined
konjak lour under stirring so that the konjak flour swelled
in water. The resulting konjak paste was then allowed to
s-~d for 5 hours at room temperature, thereby satisfac-
torily effecting swelling and dissolution of the konjak
flour. The pH of the resulting konjak paste was 8.9.
The konjak paste thus obtained was packed and sealed
in a bag made of a synthetic resin material and then heated
20 at 75~C for 90 minutes. After the heat treatment, the
packed konjak paste was cooled rapidly to 10~C in ice water,
thereby obtaining the desired konjak jelly. The p~ of the
jelly thus obtained was 8.6.
Example 2
One hundred liters of water was added to 3.5 kg of
refine2 konjak flour under stirring so that the konjak flour
swelied in water. The resulting konjak paste was then
allowed to stand for 3 hours at room temperature, thereby
satisfactorily effecting swelling and dissolution of the
30 konjak flour.
A solution of 0.7 kg of L-lysine in 7 liters of water
was added to and intimately mixed with the resulting konjak
paste. The p~ of this mixture was 9.6.
The paste thus obtained was packed and sealed in a
35 bag made of a synthetic resin material and then heated at
90~C for 30 minutes. After the heat treatment, the packed
konjak paste was cooled in running water and further cooled
to 10~C in ice water, thereby obtaining the desired konjak
133939~
g
jelly. The pH of the konjak jelly thus obtained was 9.2.
Example 3
One hundred liters of water having 0.5 kg of tri-
sodium phosphate dissolved therein was added to 4 kg of
refined konjak flour, and the mixture was stirred for 5 to
10 minutes so that the flour swelled in water. The result-
ing konjak paste was then allowed to stand for 3 hours,
thereby satisfactorily effecting swelling and dissolution
of the konjak flour.
The konjak paste thus obtained was packed in a bag
made of a synthetic resin material. The pH of the paste
was 9.4. The packed paste was then heated at 75~C for 30
minutes. Immediately after completion of the heat treat-
ment, the packed konjak paste was cooled in running water
15 and further cooled to 10~C in ice water, thereby obtaining
the desired konjak jelly. The pH of the konjak jelly thus
obtained was 8.9.
Example 4
One hundred liters of water having 0.3 kg of sodium
20 carbonate and 0.3 kg of monosodium phosphate dissolved
therein was added to 3 kg of refined konjak flour, and the
mixture was stirred ror 5 to 10 minutes so that particles of
the flour would not precipitate, thereby allowing the flour
to swell in the solution. The resulting konjak paste was
25 then allowed to stand for 3 hours at room temperature,
thereby satisfactorily effecting swelling and dissolution
of the konjak flour. The pH of the resulting konjak paste
was 8.9.
The paste thus obtained was packed and sealed in a
30 bag made of a syr,thetic resin material and then heated at
80~C for 60 minutes. After the completion of the heat
treatment, the packed paste was cooled in running water and
further cooled to 10~C in ice water, thereby obtaining the
desired konjak jelly. The pH of the konjak jelly thus
35 obtained was 8.4.
Example 5
- One hundred liters of water was added to and mixed
with 3.3 kg of refined konjak flour under stirring, thereby
1339336
--10--
allowing the flour to swell in water. A solution of 1.0 kg
of sodium carbonate in a small amount of water was added to
and mixed with the resulting konjak paste. The pH of this
mixture was 10.5.
The konjak paste thus obtained was packed and sealed
in a bag made of a synthetic resin material and then heated
at 70~C for 15 minutes. After the heat treatment, the
packed konjak paste was cooled rapidly to 10~C in ice water,
thereby obtaining the desired konjak jelly. The pH of the
jelly thus obtained was 10.3.
Example 6
To four kilograms of refined konjak flour were added
0.5 kg of sodium citrate and 0.5 kg of sodium carbonate and
mixed together. One hundred liters of water was added to
the mixture and stirred for 5 to 10 minutes, thereby allow-
ing the konjak flour to swell. The resulting konjak paste
was allowed to stand for 3 more hours at room temperature,
thereby satisfactorily effecting swelling and dissolution of
the konjak flour. The pH of this konjak paste was 9.5.
The paste thus obtained was packed and sealed in a
bag made of a synthetic resin material and then heated at
60~C for 180 minutes. After the heat treatment, the packed
paste was cooled in running water and further cooled to 10~C
in ice water, thereby obtaining the desired konjak jelly.
The pH of the jelly thus obtained was 8.9.Example 7
One hundred liters of water having 0.3 kg of
~-lysine and 0.2 kg of sodium carbonate dissolved therein
was added to and mixed with ~ kg of refined konjzk rlour
under stirring, thereby allowing the konjak flour to swell.
The resulting konjak paste was allowed to stand for 3 more
hours, thereby satisfactorily effecting swelling and dis-
solution of the konjak flour. The pH of this konjak paste
was 9.4.
The paste thus obtained was packed and sealed in a
bag made of a synthetic resin material and then heated at
80~C for 15 minutes. After the heat treatment, the packed
paste was cooled rapidly to 10~C in ice water, thereby
-11- 1~39396
obtaining the desired konjak jelly. The pH of the jelly
thus obtained was 9.2.
Example 8
One hundred liters of water having 0.2 kg of L-lysine
5 and 0.2 kg of disodium phosphate dissolved therein was added
to and mixed with 3.3 kg of refined konjak flour under
stirring, thereby allowing the konjak flour to swell. The
resulting konjak paste was allowed to stand for 3 more hours
at room temperature, thereby satisfactorily effecting swell-
10 ing and dissolution of the konjak flour. The pH of thiskonjak paste was 8.8. The paste thus obtained was packed and sealed in a
bag made of a synthetic resin material and ' ~ ~ez.ed at
80~C for 60 minutes. After the heat ~rs~ment, -~he packed
15 paste was cooled rapidly in ice water, _her~by obtai~i~g the
desired konjak jelly. The pH of the jelly thus ob.ained was
8.3.
Example 9
One hundred liters of water was added to a mixture of
20 3 kg of refined konjak flour and 0.35 kg of L-arginine under
stirring, thereby allowing the konjak flour to swell. The
resulting konjak paste was then allowed to stand for 2 hours
at room temperature, thereby satisfactorily effecting
swelling of the konjak flour. The pE of this paste was 9.1.
25 The paste thus cbtained was packed and sealeZ in a bag made
of a synthetic resin material and then heated at 80~C for
60 minutes. After the heat treatment, the packed paste was
cooled to 10~C in cold water, .hereby obtaining the desired
konjak jelly. The pE of the jelly thus obtained was 8.6.
xample 10
One hundred liters of water was added to a mixture
of 2.8 kg of refined konjak flour, 0.2 kg of L-lysine and
0.2 kg of disodium phosphate, thereby allowing the konjak
flour to swell. The resulting konjak paste was then allowed
35 to stand for 3 hours, thereby satisfactorily effecting
swelling of the konjak flour. The p~ of this paste was 9Ø
The paste thus obtained was packed and sealed in a bag made
of a synthetic resin material and then heated at 80~C for
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45 minutes. After the heat treatment, the packed paste was
cooled in cold water, thereby obtaining the desired konjak
jelly. The pH of the jelly thus obtained was 8.5.
Example 11
One hundred liters of water was added to a mixture of
4 kg of refined konjak flour, 0.5 kg of sodium citrate and
0.5 kg of sodium carbonate, thereby allowing the konjak
flour to swell. The resulting konjak paste was then allowed
to stand for 3 hours at room temperature, thereby satisfac-
10 torily effecting swelling of the konjak flour. The paste
thus obtained was packed and sealed in a bag made of a
synthetic resin material and then heated at 80~C for 15
min~es. After ~he heat treatment, the packed paste W2S
cooled tn cold water, thereby obtaining the desired konj2k
15 jelly. T~e p~ o. the ielly thus obtained was 8.8.
The konjak jelly according to the present invention
is storable over 2 long period of time and has excellent
properties as a processed food material. Accordingly, the
konjak jelly may be added to various kinds of food for the
20 purpose of calorie control, used as a binder, employed to
impart to food the fiavor and taste which are unique to
konJak or to improv~ the properties of food, or it m2y be
utilized as a food material. Thus, the konjak jelly of the
present invention enables enlargement of the range of uses
25 of konjak which has been attracting special interest
recently.
