U.S. patent application number 16/064713 was filed with the patent office on 2019-01-10 for soy sauce-like liquid seasoning and method for producing same.
This patent application is currently assigned to Kikkoman Corporation. The applicant listed for this patent is Kikkoman Corporation. Invention is credited to Akitoshi KOMURA, Takeharu NAKAHARA, Junya TAKEICHI.
Application Number | 20190008194 16/064713 |
Document ID | / |
Family ID | 59089776 |
Filed Date | 2019-01-10 |
United States Patent
Application |
20190008194 |
Kind Code |
A1 |
TAKEICHI; Junya ; et
al. |
January 10, 2019 |
SOY SAUCE-LIKE LIQUID SEASONING AND METHOD FOR PRODUCING SAME
Abstract
Provided herein is a salt-free or low-salt soy sauce-like liquid
seasoning having a desirable flavor and desirable functionality
with no contamination by microorganisms. A method for producing
such a sauce-like liquid seasoning is also provided. The salt-free
or low-salt soy sauce-like liquid seasoning having a desirable
flavor and desirable functionality is obtained by inoculating raw
material grains of primarily soybean or wheat with a koji mold to
prepare a solid koji, adding salt-free or low-salt water for
brewing to the solid koji to prepare a moromi, pasteurizing the
moromi, and fermenting the moromi with yeast in a container adapted
to reduce entry of harmful microorganisms.
Inventors: |
TAKEICHI; Junya; (Chiba,
JP) ; KOMURA; Akitoshi; (Chiba, JP) ;
NAKAHARA; Takeharu; (Chiba, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kikkoman Corporation |
Chiba |
|
JP |
|
|
Assignee: |
Kikkoman Corporation
Chiba
JP
|
Family ID: |
59089776 |
Appl. No.: |
16/064713 |
Filed: |
December 24, 2015 |
PCT Filed: |
December 24, 2015 |
PCT NO: |
PCT/JP2015/086132 |
371 Date: |
June 21, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23L 27/24 20160801;
A23L 11/09 20160801; A23V 2002/00 20130101; A23L 27/50
20160801 |
International
Class: |
A23L 27/50 20060101
A23L027/50; A23L 11/00 20060101 A23L011/00 |
Claims
1. A soy sauce-like liquid seasoning having a salt concentration of
less than 4% (w/v), and comprising 20 ppm (w/v) or more of isoamyl
alcohol, 6 ppm (w/v) or more of 2-phenylethanol, 9 ppm (w/v) or
more of isobutyl alcohol, and 10 ppm (w/v) or more of HEMF with
respect to a total nitrogen concentration of 1.0% (w/v).
2. The soy sauce-like liquid seasoning according to claim 1, which
contains 50 ppm (w/v) or less of sodium ions.
3. A method for producing the soy sauce-like liquid seasoning of
claim 1, the method comprising the steps of: 1. inoculating raw
material grains of primarily soybean or wheat with a koji mold to
prepare a solid koji, and adding water or saline to heat and
hydrolyze a moromi having a salt concentration of less than 4%
(w/v); 2. pasteurizing the moromi obtained in the step 1; and 3.
inoculating the pasteurized moromi obtained in the step 2 with
yeast, and fermenting the moromi with the yeast in a container
adapted to reduce entry of harmful microorganisms.
4. A method for producing the soy sauce-like liquid seasoning of
claim 2, the method comprising the steps of: 1. inoculating raw
material grains of primarily soybean or wheat with a koji mold to
prepare a solid koji, and adding water or saline to heat and
hydrolyze a moromi having a salt concentration of less than 4%
(w/v); 2. pasteurizing the moromi obtained in the step 1; and 3.
inoculating the pasteurized moromi obtained in the step 2 with
yeast, and fermenting the moromi with the yeast in a container
adapted to reduce entry of harmful microorganisms.
Description
TECHNICAL FIELD
[0001] The present invention relates to a salt-free or low-salt soy
sauce-like liquid seasoning, and to a method for producing such a
soy sauce-like liquid seasoning.
BACKGROUND ART
[0002] The traditional method of producing Japanese soy sauce
follows the following steps. A mixture of boiled soybeans and
roasted wheat is inoculated with a koji mold to make a soy sauce
koji. The mixture is brewed with high-concentration saline to
produce a moromi (moromi-mash), which is then fermented and matured
for an extended time period of several months to a year. The
high-concentration saline is used mainly to inhibit growth of
putrefactive bacteria. However, there have been concerns over the
possible link between excessive intake of salt and high-blood
pressure, renal disease, or the like, and there is an increasing
demand for a soy sauce with reduced salt (low sodium content).
[0003] With regard to a method for producing a salt-free or
low-salt soy sauce, an indirect production method is reported in
which, in order to prevent microorganism contamination, soy sauce
koji brewed with high-concentration saline in a traditional fashion
is desalted by removing salt through a membrane process such as by
using an ion-exchange membrane after fermentation and maturing
(see, for example, PTL 1). However, a liquid seasoning obtained by
such an indirect production method has problems, including the high
cost due to the long desalting process, and adverse effect on
flavor, such as bitterness and a harsh taste.
[0004] A direct production method is also reported in which brewing
is conducted under salt-free or low-salt conditions by controlling
pH and temperature in combination with using high nitrogen or
alcohol for brewing (see, for example, PTL 2 to PTL 4). However, a
problem of brewing under salt-free and low-pH conditions is that it
alone cannot completely prevent spoilage by microorganisms. The
brewing using high nitrogen is also problematic because it involves
poor filterability. The brewing under high temperature involves
problems such as incomplete yeast fermentation, and impartment of
an odor due to warm brewing and bitterness. Microorganism growth
can be reduced with the brewing using alcohol. However, there is a
problem that the added alcohol has an effect on yeast fermentation
and flavor.
[0005] A low-salt liquid seasoning is also reported that is
obtained by a process in which the digestion of a moromi takes
place simultaneously with alcohol fermentation. Specifically, in
digesting the raw-material carbohydrate or protein, or a mixture of
these materials with less than 2% (w/v) salt, alcohol-producing
yeasts are added after adjusting the pH of the initial moromi to 4
to 6 (see PTL 5). A drawback of this technique, however, is that
growth of microorganisms in the moromi cannot be sufficiently
reduced in early stages of fermentation, and contamination often
occurs.
[0006] A liquid seasoning is also reported that is produced by
mixing soy sauce koji with 70 to 80.degree. C. hot water to prepare
a moromi having a temperature of 50 to 57.degree. C., and
intermittently or continuously stirring the moromi while
maintaining the moromi temperature. With a salt concentration of 0
to 5% (w/v), spoilage of the moromi is prevented, and the
processing time is reduced (see PTL 6). However, while this
technique enables production of a low-salt moromi, the process
requires adding salt in a lactic acid or yeast fermentation step,
or in some other step subsequent to these steps. This makes it
difficult to obtain a low-salt soy sauce-like liquid seasoning.
[0007] As described above, there are many reports of salt-free or
low-salt soy sauce-like liquid seasonings. However, these are
insufficient in terms of practicality, and there is a need for a
salt-free or low-salt soy sauce-like liquid seasoning having a
desirable taste that can be produced without microorganism
contamination.
CITED REFERENCES
Patent Literature
[0008] PTL 1: JP-B-45-020887 [0009] PTL 2: JP-B-62-062143 [0010]
PTL 3: JP-A-5-219915 [0011] PTL 4: JP-A-2009-165377 [0012] PTL 5:
Japanese Patent No. 3065695 [0013] PTL 6: Japanese Patent No.
3827300
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0014] The present invention is intended to find a solution to the
foregoing problems, and it is an object of the present invention to
provide a salt-free or low-salt soy sauce-like liquid seasoning
having a desirable flavor and desirable functionality with no
contamination by harmful microorganisms, and a method for producing
such a sauce-like liquid seasoning.
Means for Solving the Problems
[0015] The present inventors conducted intensive studies to solve
the foregoing problems, and found that a salt-free or low-salt soy
sauce-like liquid seasoning having a desirable flavor and desirable
functionality with no contamination by harmful microorganisms can
be obtained when a solid koji prepared by inoculating raw material
grains of primarily soybean or wheat with a koji mold is prepared
into a moromi with addition of salt-free or low-salt water for
brewing, and the moromi, after pasteurization, is fermented with
yeast while preventing contamination with the use of a container
adapted to reduce entry of harmful microorganisms. The present
invention has been completed on the basis of this finding.
[0016] Specifically, the present invention is related to the
following.
[0017] (1) A soy sauce-like liquid seasoning having a salt
concentration of less than 4% (w/v), and comprising 20 ppm (w/v) or
more of isoamyl alcohol, 6 ppm (w/v) or more of 2-phenylethanol, 9
ppm (w/v) or more of isobutyl alcohol, and 10 ppm (w/v) or more of
HEMF (4-Hydroxy-2(or5)-ethyl-5. (or2)-methyl-3(2H)-furanone2,3)
with respect to a total nitrogen concentration of 1.0% (w/v).
[0018] (2) The soy sauce-like liquid seasoning described in (1)
above, which contains 50 ppm (w/v) or less of sodium ions.
[0019] (3) A method for producing the soy sauce-like liquid
seasoning of (1) or (2) above, the method comprising the steps
of:
[0020] 1. inoculating raw material grains of primarily soybean or
wheat with a koji mold to prepare a solid koji, and adding water or
saline to heat and hydrolyze a moromi having a salt concentration
of less than 4% (w/v);
[0021] 2. pasteurizing the moromi obtained in the step 1; and
[0022] 3. inoculating the pasteurized moromi obtained in the step 2
with yeast, and fermenting the moromi with the yeast in a container
adapted to reduce entry of harmful microorganisms.
Effect of the Invention
[0023] According to the present invention, a salt-free or low-salt
soy sauce-like liquid seasoning having a desirable taste and aroma
with no contamination by harmful microorganisms can be
obtained.
[0024] Also, the salt-free liquid seasoning produced by the present
invention has an extremely low sodium ion concentration, and a
desirable flavor, and can be used as a soy sauce-like liquid
seasoning suited for people suffering from, for example, high-blood
pressure, or renal disease.
EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0025] The present invention is described below in detail.
[0026] In the present invention, a soy sauce moromi having a salt
concentration of less than 4% (w/v) is prepared by mixing water or
saline into a solid koji prepared from raw material grains. The
moromi is then heated and hydrolyzed at 25 to 57.degree. C. for 0
to 48 hours. Preferably, 70 to 80.degree. C. hot water or saline is
mixed into a solid koji, and the mixture is stirred intermittently
or continuously in a tank while maintaining the moromi at 50 to
57.degree. C., and hydrolyzed with enzyme for 15 to 30 hours, as in
Japanese Patent No. 3827300.
[0027] As used herein, "raw material grains" refers to, for
example, protein materials such as whole soybean, defatted soybean,
soy protein, wheat gluten, green pea, broad pea, and red pea, and
starch materials such as wheat, barley, rye, wheat bran, rice, rice
bran, corn, and starch pulp. These may be used alone or in
combination.
[0028] The solid koji used herein is obtained by inoculating a
protein material prepared by using an ordinary method or a mixture
of the protein material and a starch material with a koji mold such
as Aspergillus sojae, and Aspergillus oryzae, and conducting solid
culturing for 2 to 3 days (koji-making).
[0029] When mixing protein and starch materials, these are mixed at
a weight ratio of preferably 1:0.25 to 4 when, for example, a
liquid seasoning similar to a regular soy sauce is desired.
However, the combination ratio of these materials are not
particularly limited.
[0030] The water or saline used for brewing is used in amounts that
are sufficient to soak koji. Typically, the amount of water or
saline is preferably 1 to 4 times the weight of koji by volume
(v/w). At the time of thermal hydrolysis, an edible acid, an enzyme
agent, or activated carbon may be added to improve mold resistance,
hydrolysis efficiency, and flavor, as will be described later. For
the purpose of reducing bubbling during yeast fermentation, an
emulsion-type silicone defoaming agent may be added in a final
concentration of 0.01 to 0.5% (w/v).
[0031] At the time of thermal hydrolysis, an enzyme agent may be
added in a final concentration of 0.001 to 1% (w/v) to promote
moromi hydrolysis. Examples of the enzyme agent include protease
(endoprotease, exoprotease), cellulase, and pectinase.
[0032] The thermal hydrolysis is followed by heat pasteurization of
the soy sauce moromi having a salt concentration of less than 4%
(w/v). The heat pasteurization method is not particularly limited,
and may be any of, for example, UHT (ultra high temperature heating
method), HTST (high temperature short time method sterilization),
retort, pressurized tank, steam injection, steam infusion,
autoclave, plate heater, surface scrape, Joule heat-exchange, and
tubular pasteurization methods. Preferred are methods using a
pressurized tank, and a tubular pasteurizer. For example, the
moromi may be pasteurized by applying heat under applied pressure
while uniformly stirring the moromi in a pressurized tank.
Pasteurization of unwanted bacteria becomes insufficient when the
pasteurization temperature is too low, or when the pasteurization
time is too short, and it is not preferable. Conversely, the flavor
of the liquid seasoning deteriorates when the pasteurization
temperature is too high, or when the pasteurization time is too
long, and it is not preferable. Preferably, the moromi is
pasteurized for, for example, 2 minutes to 180 minutes at
80.degree. C., 5 seconds to 15 minutes at 121.degree. C., or 1
second to 30 seconds at 130.degree. C., though the optimum
conditions vary with the selected method of pasteurization.
[0033] The pH of the prepared moromi may be adjusted to improve
mold resistance or to adjust taste. Desirably, the pH is adjusted
to 3.0 to 7.0, preferably 4.0 to 5.5 from the viewpoint of mold
resistance and yeast fermentation. The pH may be adjusted at the
time of thermal hydrolysis, or before or after the heat
pasteurization of the moromi. Examples of the edible acid as a pH
adjuster include lactic acid, acetic acid, malic acid, citric acid,
gluconic acid, and adipic acid. Preferred for flavor is lactic
acid.
[0034] For smooth yeast fermentation, 0 to 20% (w/v) of sugar may
be added to the moromi. The sugar may be any sugar, as long as it
can be utilized by yeast. Examples include glucose, fructose,
sucrose, maltose, mannose, and glycerol. However, it is desirable
to use glucose in view of utilization efficiency. The important
aroma component HEMF of soy sauce can be increased with the use of
a pentose, such as ribose and xylose, even when the soy sauce is
salt-free or low-salt, as described in JP-A-2001-120293. The sugars
may be used alone or in combination. It is also possible to use
food materials containing these sugars. Examples of such food
materials include a table sugar, a high fructose corn syrup (liquid
sugar which includes less than 50% of fructose), a high fructose
corn syrup (liquid sugar which includes 50% or more and less than
90% of fructose), a soft brown sugar, and a molasses.
[0035] Before yeast fermentation, an enzyme agent may be added in a
final concentration of 0.001 to 1% (w/v) to promote moromi
hydrolysis, or to improve pressability. Examples of the enzyme
agent include protease (endoprotease, exoprotease), cellulase, and
pectinase.
[0036] Before yeast fermentation, activated carbon may be added to
the moromi to eliminate bitterness, and improve flavor. Preferably,
the activated carbon is a powder, more preferably a powder with an
average particle size of 10 to 100 .mu.m. The activated carbon is
added preferably in an amount of 0.1 to 5% (w/w) with respect to
the raw material of the moromi. The kind of activated carbon may be
appropriately selected according to the intended use. For example,
activated carbons having functions such as elimination of
bitterness, removal of bad odor, adjustment of taste, and
adjustment of color may be used in combination.
[0037] The yeast used in the present invention is not particularly
limited. For example, Saccharomyces cerevisiae, Zygosaccharomyces
rouxii, and Kluyveromyces marxianus may be used. Because the moromi
of the present invention is salt-free or low-salt, it is also
possible to use other yeasts, including, for example, weakly
halotolerant wine yeasts, beer yeasts, and shochu (distilled
alcoholic beverage) yeasts. Preferably, the yeast is added in a
concentration of 1.times.10.sup.5 cells or more, preferably
1.times.10.sup.6 to 1.times.10.sup.7 cells per gram of moromi.
[0038] For yeast fermentation, the moromi is charged into a
container adapted to reduce the contamination of harmful
microorganisms. Here, the container adapted to reduce the
contamination of harmful microorganisms is a container that is
structured to block inside of the container from ambient air. For
experimental purposes, the container may be a polypropylene jar
processed for removal of bacteria or a glass media bottle. For
industrial production, the container may be a jar fermenter with a
function to supply air without bacteria into the container, or a
pressurized fermentation tank. For removal of bacteria in air, a
filter capable of collecting at least 99.97% of dust of 0.3-.mu.m
or larger may be used, for example, such as a HEPA filter.
[0039] The yeast is fermented at a yeast growing temperature,
specifically at 15 to 45.degree. C., preferably 20 to 30.degree.
C., for 1 to 90 days, preferably 3 to 28 days.
[0040] The amount of alcohol produced in the soy sauce-like liquid
seasoning of the present invention may be adjusted in the 0 to 20%
(w/v) range according to the concentration of the sugar added in
the fermentation step, the type of the yeast used, or the
fermentation conditions. Alcohol may also be added at the
completion of the fermentation. However, in order to provide the
soy sauce-like liquid seasoning with the soy sauce-like flavor, the
alcohol content is preferably less than 8% (w/v), more preferably 2
to 7% (w/v). The alcohol concentration may be measured by using a
known method, for example, with a measurement kit using gas
chromatography or an enzyme method.
[0041] After fermentation, the moromi may be processed by an
ordinary method, such as pressing, heating, refining, and
filtration, so that a soy sauce-like liquid seasoning having a
desirable flavor and functionality with a salt concentration of
less than 4% (w/v) can be obtained. The salt concentration can be
measured by using methods such as potentiometry and the Mohr's
method.
[0042] Unlike the known salt-free or low-salt soy sauce-like liquid
seasoning, the soy sauce-like liquid seasoning of the present
invention satisfies the following conditions for aroma component
concentration, and has a flavor that more closely resembles the soy
sauce-like flavor.
[0043] (1) The isoamyl alcohol concentration is 20 ppm (w/v) or
more with respect to the total nitrogen concentration of 1.0%
(w/v)
[0044] (2) The 2-phenylethanol concentration is 6 ppm (w/v) or more
with respect to the total nitrogen concentration of 1.0% (w/v)
[0045] (3) The isobutyl alcohol concentration is 9 ppm (w/v) or
more with respect to the total nitrogen concentration of 1.0%
(w/v)
[0046] (4) The HEMF concentration is 10 ppm (w/v) or more with
respect to the total nitrogen concentration of 1.0% (w/v)
[0047] It is known that isoamyl alcohol and 2-phenylethanol are
responsible for the base note of sake, and that these alcohols,
along with isobutyl alcohol, are aroma components of yeast
fermentation origin that improve the flavor of soy sauce. The
concentration of these aroma components can be measured by, for
example, GC-MS (gas chromatography-mass spectrometry), or GC-FID
(gas chromatography-flame ionization detection).
[0048] It is known that HEMF, an important aroma component of soy
sauce, reduces its concentration in low-salt brewing process (J.
Agric. Food Chem. Vol 44, 3273-3275, 1996). The soy sauce-like
liquid seasoning of the present invention, however, has the same
levels of HEMF concentration as a regular soy sauce, and has the
soy sauce-like flavor.
[0049] The salt-free soy sauce-like liquid seasoning of the present
invention, which is obtained without using any salt in the water
used in the brewing step, has a sodium ion concentration of 50 ppm
(w/v) or less. The salt-free soy sauce-like liquid seasoning of the
present invention differs from known salt-free soy sauce-like
liquid seasonings in this respect, and has a lower sodium
concentration than known salt-free soy sauce-like liquid
seasonings. The sodium ion concentration can be measured by using
methods such as atomic absorption spectrometry and ICP emission
spectrometry.
[0050] The following describes the present invention in greater
detail using Examples. It should be noted that the technical scope
of the present invention is in no way limited by the following
Examples.
EXAMPLES
1. Production of Salt-Free Liquid Seasoning
Preparation of Soy Sauce Koji
[0051] Defatted processed soybean (50%, w/w), and roasted smashed
wheat (50%, w/w) were mixed to prepare a soy sauce koji. The
defatted processed soybeans were used after being soaked with water
(130%, w/w) and boiled. The raw material was inoculated with a seed
starter of Aspergillus sojae, and was processed for 42 hours using
an ordinary method to obtain a soy sauce koji (koji-making).
Moromi Preparation
[0052] The above soy sauce koji was mixed with 200 weight parts of
hot water (preheated to 70.degree. C.; containing no salt) with
respect to 100 weight parts of the koji. The mixture was then
heated and hydrolyzed at 55.degree. C. for 24 hours by being
continuously stirred at 100 rpm in a hydrolysis tank equipped with
an insulating jacket having stirring vanes on the rotating shaft.
This produced a salt-free moromi.
Moromi Pasteurization
[0053] After being brought to pH 4.0 to 5.0 with lactic acid as
shown in Table 1, the salt-free moromi (Examples 1-1 to 1-4, 300 g
each) was put in a glass media bottle, and pasteurized with an
autoclave at 121.degree. C. for 5 minutes. To the moromi of each
group was then added 50% (w/v) glucose processed for removal of
bacteria in a final concentration of 5% (w/v), as shown in Table
1.
TABLE-US-00001 TABLE 1 Supplement Fermen- Pasteur- Moromi sugar
(final tation ization pH concentration) Yeast temp. Com. None 4.0
5% glucose Z. rouxii 25.degree. C. Ex. 1-1 Com. None 4.5 5% glucose
Z. rouxii 25.degree. C. Ex. 1-2 Com. None 5.0 5% glucose Z. rouxii
25.degree. C. Ex. 1-3 Ex. 1-1 121.degree. C., 5.0 5% glucose Z.
rouxii 20.degree. C. 5 min Ex. 1-2 121.degree. C., 5.0 5% glucose
Z. rouxii 25.degree. C. 5 min Ex. 1-3 121.degree. C., 5.0 5%
glucose Z. rouxii 30.degree. C. 5 min Ex. 1-4 121.degree. C., 5.0
None Z. rouxii 30.degree. C. 5 min
Yeast Fermentation
[0054] A precultured soy sauce yeast (Zygosaccharomyces rouxii) was
added to the moromi in a concentration of 1.times.10.sup.7 cells/g
moromi, and the mixture was fermented at a moromi temperature of 20
to 30.degree. C. for 14 days, as shown in Table 1.
Refinement
[0055] After yeast fermentation, the moromi was pressed, heated,
and racked to obtain a refined soy sauce-like liquid seasoning.
Table 2 shows the common viable bacteria count, and the analytical
values of the components of the obtained soy sauce-like liquid
seasoning.
Common Viable Bacteria Count, and Component Analysis
[0056] For counting of common viable bacteria, the soy sauce-like
liquid seasoning was cultured in a medium prepared by adding 30
.mu.g/ml of nystatin to standard agar medium PEARLCORE
(manufactured by Eiken Chemical Co., Ltd.), and the number of grown
colonies was counted. It is to be noted that the common viable
bacteria count obtained by this method does not include yeasts, and
represents mainly the number of contaminating bacteria. The total
nitrogen (TN) concentration, the alcohol concentration, and the pH
were determined by using the methods described in Soy Sauce Testing
Methods (published Mar. 1, 1985, ed. Japan Soy Sauce Research
Center). The salt concentration was determined by the Mohr's
method. The glutamic acid concentration was determined by using an
amino acid analyzer.
TABLE-US-00002 TABLE 2 Common viable bacteria count NaCl TN Glu Alc
after yeast fermentation (cfu/ml) % (w/v) % (w/v) % (w/v) pH %
(v/v) Com. Ex. 1-1 8.7 .times. 10.sup.7 (spoilage) 0 1.05 0.73 4.1
2.9 Com. Ex. 1-2 3.8 .times. 10.sup.8 (spoilage) 0 1.10 0.82 4.2
2.3 Com. Ex. 1-3 6.0 .times. 10.sup.8 (spoilage) 0 1.08 0.85 4.1
2.1 Ex. 1-1 <1 .times. 10.sup.3 0 1.14 0.78 4.7 5.9 Ex. 1-2
<1 .times. 10.sup.3 0 1.15 0.69 4.7 5.7 Ex. 1-3 <1 .times.
10.sup.3 0 1.15 0.73 4.6 5.4 Ex. 1-4 <1 .times. 10.sup.3 0 1.16
0.70 4.6 2.1
[0057] As can be seen from the results for Comparative Examples 1-1
to 1-3 in Table 2, it was not possible to obtain the desired soy
sauce-like liquid seasoning when the moromi was not pasteurized,
and spoilage occurred during the brewing process, even when the
initial pH of the moromi was lowered to 4.0. On the other hand, the
soy sauce-like liquid seasoning was obtained with no spoilage in
the brewing process when the pasteurization step was conducted as
in Examples 1-1 to 1-4, even when the alcohol concentration was low
as in Example 1-4. The yeast fermentation was considered desirable
also from an alcohol concentration standpoint. It was also
confirmed that the preferred fermentation temperature is 20 to
30.degree. C. to prevent an effect on yeast fermentation and
flavor.
2. Modification of Method for Producing Salt-Free or Low-Salt Soy
Sauce-Like Liquid Seasoning
[0058] Preparation of Moromi with Increased Amount of Soy Sauce
Koji
[0059] As in Example 1, the soy sauce koji was mixed with 140
weight parts of heated 70.degree. C. hot water with respect to 100
weight parts of the koji. In Example 2-4 and Comparative Examples
2-1 and 2-2, salt was added in the final concentrations shown in
Table 3. After adding 1.5% (w/w) of activated carbon (Kujyaku TK2;
manufactured by Kawakita Chemical Co., Ltd.) with respect to the
raw material, the pH was adjusted to 4.8 with lactic acid, and the
mixture was heated and hydrolyzed at 55.degree. C. for 24 hours by
being continuously stirred at 100 rpm in a hydrolysis tank equipped
with an insulating jacket having stirring vanes on the rotating
shaft. This produced a moromi. This moromi had a larger proportion
of the soy sauce koji than the moromi of Example 1.
Production of Soy Sauce-Like Liquid Seasoning
[0060] The above moromi was pasteurized at 121.degree. C. for 5
minutes using a jar fermenter, and 50% (w/v) glucose processed for
removal of bacteria was added in a final concentration of 5% (w/v).
To the mixture was then added precultured yeast (Zygosaccharomyces
rouxii, Saccharomyces cerevisiae, Kluyveromyces marxianus) in a
concentration of 1.times.10.sup.7 cells/g moromi. After adding a
commercially available enzyme agent (endoprotease, exoprotease) in
a final concentration of 0.1% (w/w), the mixture was fermented with
the yeast at a moromi temperature of 25.degree. C. or 30.degree. C.
for 14 days, as shown in Table 3.
TABLE-US-00003 TABLE 3 NaCl Fermen- Moromi % tation pH (w/v) Yeast
Temp. Ex. 2-1 4.8 0 Z. rouxii 25.degree. C. Ex. 2-2 4.8 0 S.
cerevisiae 25.degree. C. Ex. 2-3 4.8 0 K. marxianus 30.degree. C.
Ex. 2-4 4.8 3 Z. rouxii 25.degree. C. Com. 4.8 16 S. cerevisiae
25.degree. C. Ex. 2-1 Com. 4.8 16 K. marxianus 30.degree. C. Ex.
2-2
Refinement and Flavor Evaluation
[0061] After yeast fermentation, the moromi was pressed, heated,
and racked to obtain a refined soy sauce-like liquid seasoning.
Table 4 shows the analytical values of the components and the
results of flavor evaluation of the liquid seasoning. The flavor
was evaluated according to the following criteria.
[0062] Excellent: Very desirable
[0063] Good: Desirable
[0064] Poor: Undesirable
TABLE-US-00004 TABLE 4 NaCl TN Glu Alc Flavor % (w/v) % (w/v) %
(w/v) pH % (v/v) evaluation Comment Ex. 2-1 0 1.51 0.91 4.7 4.9
Excellent Sweet aroma Ex. 2-2 0 1.51 0.93 4.7 5.6 Good Fruity
aroma, sake- like flavor Ex. 2-3 0 1.49 0.88 4.7 5.3 Good
Fermentation odor, pickles odor Ex. 2-4 3 1.47 0.88 4.7 5.1
Excellent Light soy sauce odor with sweet aroma Com. Ex. 2-1 16
1.48 0.90 4.8 0 Poor Raw material odor, potato odor Com. Ex. 2-2 16
1.48 0.90 4.8 0 Poor Raw material odor, potato odor
[0065] By increasing the amount of the soy sauce koji used for
moromi preparation, and adding an enzyme agent for yeast
fermentation, it was possible to produce liquid seasonings having a
desirable flavor with high total nitrogen concentration and high
glutamic acid concentration.
[0066] The liquid seasonings fermented without salt as in Examples
2-1 and 2-2 had a sweet, elegant aroma as a whole, and the flavor
was desirable. The low-salt liquid seasoning of Example 2-4 that
underwent yeast fermentation under low salt concentration (3%, w/v)
had an aroma that was more like a soy sauce, and the flavor was
also desirable.
[0067] The sake yeast S. cerevisiae used in Example 2-2, and the
heat-resistant yeast K marxianus used in Example 2-3 had higher
fermentation rates than the soy sauce yeast (Z. rouxii) used in
Example 2-1, had a tendency to produce more alcohol, and are more
desirable in terms of mold resistance. However, these yeasts are
non-halotolerant yeasts, and do not grow well and fail to produce
alcohol under high salt concentrations as in Comparative Examples
2-1 and 2-2, and cannot be used in the traditional brewing of soy
sauce. An advantage of the salt-free or low-salt fermentation of
the present invention is that it allows the use of these
non-halotolerant microorganisms.
3. Production of Salt-Free Liquid Seasoning Having Improved Soy
Sauce-Like Flavor Production of Pentose-Added Soy Sauce-Like Liquid
Seasoning
[0068] A 50% (w/v) glucose solution processed for removal of
bacteria, and ribose or xylose were added to a pasteurized
salt-free moromi produced in the same manner as in Example 2. These
were added in the final concentrations (w/v) shown in Table 5. To
the mixture was added soy sauce yeast Z. rouxii as in Example 2-1,
and a commercially available enzyme agent (endoprotease,
exoprotease) was added in a final concentration of 0.1% (w/w). The
mixture was then fermented at a moromi temperature of 25.degree. C.
for 14 days. After yeast fermentation, the moromi was pressed,
heated, and racked to obtain a refined soy sauce-like liquid
seasoning.
TABLE-US-00005 TABLE 5 NaCl Supplement Fermen- Moromi % sugar
(final tation pH (w/v) Yeast concentration) temp. Ex. 2-1 4.8 0 Z.
rouxii 5% glucose 25.degree. C. (control) Ex. 3-1 4.8 0 Z. rouxii
4% glucose, 25.degree. C. 1% ribose Ex. 3-2 4.8 0 Z. rouxii 4%
glucose, 25.degree. C. 1% xylose
[0069] Table 6 shows the analytical values of the components and
the results of flavor evaluation of the soy sauce-like liquid
seasoning. The flavor evaluation confirmed that adding ribose or
xylose for fermentation enhances the soy sauce-like aroma and
improves the quality, though the analytical values of the common
components remained essentially the same. The result suggests that
adding pentose is effective for further improvement of the soy
sauce-like flavor of the salt-free soy sauce-like liquid
seasoning.
TABLE-US-00006 TABLE 6 NaCl TN Glu Alc % (w/v) % (w/v) % (w/v) pH %
(v/v) Flavor evaluation Ex. 2-1 0 1.51 0.91 4.7 4.9 Sweet aroma Ex.
3-1 0 1.45 0.78 4.7 4.8 Characteristic fermentation odor of soy
sauce Ex. 3-2 0 1.47 0.90 4.7 3.0 Characteristic fermentation odor
of soy sauce, sharp
4. Comparison of Desalted Soy Sauce, Commercially Available
Koikuchi (Dark-Colored) Soy Sauce, and Commercially Available
Salt-Free Soy Sauce Preparation of Desalted Soy Sauce
[0070] Boiled and denatured defatted soybeans, and smashed roasted
wheat were mixed in equal amounts, and the mixture was inoculated
with a seed starter, and processed for 42 hours under aeration to
obtain a soy sauce koji (koji-making). The koji was mixed into
saline, and fermented and matured under controlled conditions where
the moromi was fermented at 25 to 30.degree. C. for 150 days with
appropriate stirring using an ordinary method. This was followed by
pressing and filtration, and an unheated soy sauce having a salt
concentration of about 18% (w/v), and a total nitrogen
concentration of about 1.7% (w/v) was obtained.
[0071] The unheated soy sauce was heated at 80.degree. C. for 1
hour, and refined by filtration. The resulting soy sauce was
desalted with an electrodialyzer (manufactured by Astom
Corporation), and a desalted soy sauce of pH 4.7 having a salt
concentration of 0.1% (w/v), a total nitrogen concentration of
about 1.6% (w/v), and a glutamic acid concentration of about 0.9%
(w/v) was obtained.
Analysis of Aroma Components
[0072] The concentrations of isoamyl alcohol, 2-phenylethanol,
isobutyl alcohol, and HEMF were measured by using the quantitative
analysis method described in J. Agric. Food Chem. Vol. 39, 934,
1991. Specifically, these were analyzed by gas chromatography
(6890N; manufactured by Agilent Technologies), and the content of
each aroma component was determined by the standard curve method
using a standard sub stance.
[0073] Table 7 shows the results of aroma component analysis for
the liquid seasonings of Examples (Examples 1-4, 2-1, 2-2, 2-4,
3-1, and 3-2), a desalted soy sauce, a commercially available
koikuchi (dark-colored) soy sauce (manufactured by Kikkoman
Corporation), and a commercially available soy sauce-like liquid
seasoning brewed with alcohol (commercially available salt-free soy
sauce). It was confirmed that the isoamyl alcohol, 2-phenylethanol,
and isobutyl alcohol concentrations with respect to 1% (w/v) total
nitrogen concentration tended to be overall higher in the soy
sauce-like liquid seasonings of the present invention than in the
desalted soy sauce and the commercially available soy sauce, and
that the soy sauce-like liquid seasonings of the present invention
had isoamyl alcohol concentration of 20 ppm (w/v) or more,
2-phenylethanol concentration of 6 ppm (w/v) or more, and isobutyl
alcohol concentration of 9 ppm (w/v) or more and were salt-free or
low-salt liquid seasonings having a desirable flavor. It was also
confirmed that the liquid seasonings of Examples 2-1, 2-2, and 2-4
had the same levels of HEMF concentration as the desalted soy sauce
and the commercially available koikuchi (dark-colored) soy sauce,
and also had the soy sauce-like flavor.
[0074] It was also confirmed that the salt-free liquid seasonings
prepared by adding pentose as in Examples 3-1 and 3-2 had even
higher HEMF concentrations, and that a liquid seasoning having an
enhanced soy sauce-like flavor can be obtained when pentose is
added in implementing the present invention.
TABLE-US-00007 TABLE 7 Concentration (ppm, w/v) with respect to TN
1% (w/v) NaCl % Alc % TN % Isoamyl 2-Phenyl Isobutyl (w/v) (w/v)
(w/v) alcohol ethanol alcohol HEMF Production summary Ex. 1-4 0 2.1
1.16 23.7 6.9 9.3 12.1 No supplement sugar, low alcohol Ex. 2-1 0
4.9 1.51 99.1 31.3 28.6 18.8 Ex. 2-2 0 5.6 1.51 48.2 15.3 21.2 11.7
Fermentation with S. cerevisiae Ex. 2-4 3.0 5.1 1.47 100.8 45.0
44.6 14.2 Fermentation with 3% salt Ex. 3-1 0 4.8 1.45 70.5 18.0
29.9 41.0 1% Ribose was added for fermentation Ex. 3-2 0 3.0 1.47
74.4 18.1 28.9 29.8 3% Xylose was added for fermentation Desalted
soy 0.1 2.3 1.66 2.3 1.0 3.5 13.4 Brewing followed by sauce
electrodialysis desalting Commercially 16.0 3.0 1.60 2.6 3.0 4.4
16.6 Brewing available koikuchi (dark- colored) soy sauce
Commercially 0.2 13.4 2.06 0.0 1.8 0.0 2.1 Brewed with alcohol
available salt-free soy sauce
Analysis of Metal Ion Concentration
[0075] The metal ion concentration was analyzed by atomic
absorption spectrophotometry with air-acetylene flame, using an
atomic absorption spectrophotometer AA6300 (manufactured by
Shimadzu Corporation). A standard curve was created using a
standard solution for atomic absorption spectrophotometry
(manufactured by Kanto Kagaku).
[0076] Table 8 shows the metal ion concentrations of the salt-free
soy sauce-like liquid seasoning of Example 2-1, the desalted soy
sauce prepared in Section 4 above, and a commercially available
salt-free soy sauce. The salt-free soy sauce-like liquid seasoning
of the present invention had a considerably lower sodium ion
concentration than the other soy sauces. The desalted soy sauce had
a low potassium ion concentration, but the sodium ion concentration
was relatively high due to electrodialysis efficiency. These
results suggest that the salt-free soy sauce-like liquid seasoning
of the present invention is a liquid seasoning having a
considerably lower sodium ion concentration than traditional
salt-free or low-salt soy sauce-like liquid seasonings, and that is
functionally desirable for, for example, the prevention of
salt-sensitive hypertension.
TABLE-US-00008 TABLE 8 Na ppm K ppm Mg ppm (w/v) (w/v) (w/v) Ex.
2-1 1 433 75 Desalted soy sauce 530 8 60 Commercially available 78
545 97 salt-free soy sauce
Sensory Evaluation
[0077] The sensory evaluation was made by eight trained panelists
having a discrimination ability, and these panelists were asked to
give scores. Specifically, the salt-free liquid seasonings of
Examples 1-4, 2-1, 2-2, 3-1, and 3-2, a sample prepared by adding
alcohol to the sample of Example 2-1 in a final concentration of
8.5% (w/v), and a commercially available salt-free soy sauce were
evaluated for intensities of saltiness, umami, bitterness, and soy
sauce-like taste, and for palatability (pleasantness), relative to
the desalted soy sauce prepared in Section 4 above. The evaluation
criteria are as follows.
[0078] 1: Low intensity/poor palatability
[0079] 2: Slightly low intensity/slightly poor palatability
[0080] 3: Same intensity/same palatability
[0081] 4: Slightly high intensity/slightly desirable
palatability
[0082] 5: High intensity/desirable palatability
[0083] Table 9 shows the results of the sensory evaluation test for
the salt-free liquid seasonings. The scores presented in the table
are the mean values of the eight panelists. The samples of Examples
2-1 and 2-2 as the products of the present invention had improved
umami and palatability than the desalted soy sauce. It was
confirmed that the samples of Examples 3-1 and 3-2 also had an
improved soy sauce-like taste due to increased HEMF. On the other
hand, it was confirmed that the alcohol-added sample and the
commercially available salt-free soy sauce had a strong alcohol
taste, and tended to be unpleasant. The products of the present
invention had a soy sauce-like aroma due to the high total nitrogen
concentration and the high glutamic acid concentration, and the
same levels of alcohol concentration as a brewed soy sauce. These
contributed to the improved palatability.
TABLE-US-00009 TABLE 9 Average score Soy sauce- like Saltiness
Umami Bitterness taste Palatability Comment Desalted soy -- -- --
-- -- Plain taste with harshness sauce Ex. 1-4 2.8 3.0 3.0 2.8 3.1
Mild soy sauce aroma, desirable flavor Ex. 2-1 3.0 3.6 3.4 2.8 3.6
Elegant aroma, desirable flavor Ex. 2-2 3.3 3.6 3.3 2.6 3.5 Elegant
sake-like flavor Ex. 3-1 3.3 3.4 3.4 3.4 3.5 Strong soy sauce-like
aroma, desirable flavor Ex. 3-2 3.4 3.1 3.6 3.5 3.8 Sharp soy
sauce-like aroma, desirable flavor Ex. 2-1 + alcohol 2.8 3.0 3.5
2.0 2.0 Strong alcohol taste, no soy (8.5%) sauce-like flavor
Commercially 3.0 2.8 4.1 1.9 1.5 Strong alcohol taste with
available salt- bitterness free soy sauce
[0084] The same sensory evaluation was conducted for the low-salt
liquid seasonings, specifically, for the sample of Example 2-4 (3%
salt), and for a sample prepared by adding salt to a desalted soy
sauce in a final concentration of 3% (N=8). By the presence of a
small quantity of salt, the sample of Example 2-4 containing 3%
salt had greatly improved saltiness, umami, soy sauce-like taste
and palatability, and was evaluated as a more-balanced liquid
seasoning compared with the desalted soy sauce to which salt was
added to have the same salt concentration.
[0085] These results confirmed that the soy sauce-like liquid
seasoning of the present invention, despite being salt-free or
low-salt, has an excellent flavor, and more desirable palatability
than the desalted soy sauce, the commercially available salt-free
soy sauce, and the soy sauce prepared by adding salt or alcohol to
the desalted soy sauce.
Experimental Production of Salt-Free Liquid Seasoning
[0086] (A) High-Temperature Hydrolysis with Acetic
Acid--Pasteurization of Moromi Solution--Yeast Fermentation
[0087] A soy sauce koji (7.8 kg) containing defatted processed
soybeans (50%, w/w) and roasted smashed wheat (50%, w/w) was
charged into a 30-L jar fermenter with 12 L of 75.degree. C. hot
water and 100 mL of acetic acid. The mixture was stirred at
55.degree. C. for 24 hours for hydrolysis. The hydrolyzed moromi
was filtered through filter paper to separate liquid from solid,
and the filtrate (moromi solution) was heat pasteurized at
121.degree. C. for 3 minutes. To the pasteurized moromi solution
was added 1 L of glucose, and 1.times.10.sup.6 cells/mL of soy
sauce yeast (Zygosaccharomyces rouxii), and the mixture was
fermented at a moromi temperature of 30.degree. C. for 7 days.
(B) High-Temperature Hydrolysis with Lactic Acid--Pasteurization of
Moromi Solution--Yeast Fermentation
[0088] The same soy sauce koji used in (A) (7.8 kg) was charged
into a 30-L jar fermenter with 12 L of 75.degree. C. hot water and
100 mL of lactic acid. The mixture was stirred at 55.degree. C. for
24 hours for hydrolysis. The hydrolyzed moromi was filtered through
filter paper to separate liquid from solid, and the filtrate
(moromi solution) was heat pasteurized at 121.degree. C. for 3
minutes. To the pasteurized moromi solution was added 1 L of
glucose, and 1.times.10.sup.6 cells/mL of soy sauce yeast
(Zygosaccharomyces rouxii), and the mixture was fermented at a
moromi temperature of 30.degree. C. for 7 days.
(C) High-Temperature Hydrolysis with Lactic Acid--Moromi
Pasteurization--Yeast Fermentation
[0089] The same soy sauce koji used in (A) (7.8 kg) was charged
into a 30-L jar fermenter with 12 L of 75.degree. C. hot water and
100 mL of lactic acid. The mixture was stirred at 55.degree. C. for
24 hours for hydrolysis. The hydrolyzed moromi was heat pasteurized
at 121.degree. C. for 3 minutes while being stirred in the jar
fermenter. To the pasteurized moromi was added 1 L of glucose, and
1.times.10.sup.6 cells/mL of soy sauce yeast (Zygosaccharomyces
rouxii), and the mixture was fermented at a moromi temperature of
30.degree. C. for 7 days.
Results
[0090] Table 11 shows the analytical values and the results of
flavor evaluation of these liquid seasoning samples. There was no
large difference between the analytical values of the samples.
However, the samples were greatly different in terms of flavor. The
acetic acid hydrolysis sample (A) had a notable acid odor, and the
taste was too plain. The moromi solution pasteurized sample (A, B)
had an off-flavor including an oxidation odor and a deterioration
odor. The sample of (C) had umami with a flavor that most closely
resembled a soy sauce.
TABLE-US-00010 TABLE 11 TN Glu Alcohol (%, (%, (%, Flavor Sample pH
w/v) w/v) w/v) evaluation (A) Acetic acid- 4.98 1.72 1.26 5.78 Acid
odor and dete- Pasteurization of rioration odor are moromi solution
present Acid taste with little soy sauce- like taste (B) Lactic
acid- 5.02 1.74 1.37 4.67 Bitterness and acid Pasteurization of
odor/deterioration moromi solution odor are present Sharp flavor
(C) Lactic acid- 5.03 1.90 1.51 5.55 Soy sauce-like Moromi pasteur-
flavor ization Strong umami
[0091] These results confirmed that the liquid seasoning of the
present invention produced by yeast fermentation without
solid-liquid separation had a flavor greatly different from that of
the liquid seasoning produced by yeast fermentation with
solid-liquid separation.
* * * * *