Fried instant noodles and method for manufacturing the same

A method for manufacturing a fried instant noodle wherein noodle strings comprising cereal flours, a chemical leavening agent and at least one enzyme selected from the group consisting of amylase and protease are steamed and then fried. The fried instant noodles exhibit a low oil absorption, a low calorie content, no oily odor or flavor and superior gastronomical taste and texture. The noodles can be reconstituted to a ready to eat state in a short time.

This invention relates to fried instant noodles, a method for manufacturing 
the same and a cereal flour mix composition suitable for the manufacture 
of the fried instant noodles. 
BACKGROUND OF THE INVENTION 
Instant noodles have a widespread consumer's support for their superior 
instant cooking characteristics by which the noodles can be very easily 
made ready to eat by merely pouring boiling water onto the noodles in a 
dish or heat-cooking in a short time, and for their characteristics as a 
staple food and their good preservative quality. Those instant noodles are 
classified according to the drying method into a fried noodle (fried 
type), a hot air-dried noodle (non-fried type) and a freeze-dried noodle 
(freeze-dried type). The fried type, in particular Chinese-style noodles 
are at the top of the instant noodles, since they are very good in respect 
of instant cooking, handling, ease of manufacture, keeping quality and the 
like, with a low price. 
The fried instant noodles absorb a large amount of oil when fried in oil, 
which results in higher calorie than non-fried noodles and freeze-dried 
noodles. In recent years, there is a strong consumer demand for fried 
instant noodles with low oil absorption, since the consumer has become 
highly dedicated to reducing calories in order to prevent diseases of 
adult people and the like. In addition, there has been a tendency toward 
good, light gastronomical texture with no oiliness in the fried instant 
noodles. Therefore, fried instant noodles are desired with low oil 
absorption. 
Japanese Patent Publication No. 30431/93 has proposed a method for 
manufacturing the instant noodles wherein raw noodle strings containing an 
alkaline gas generating base (an alkaline chemical leavening agent) are 
prepared, an aqueous acidic solution is applied to the raw noodle strings, 
the noodle strings are steamed, expanded and dried using a hot air, frying 
in oil or the like to give the final instant noodles. Further, it is 
mentioned therein that this method can reduce the oil content of the dried 
noodle even when dried in oil, thus providing improved keeping quality of 
the product. However, the problems remain that the resulting dried noodles 
have a nutritiously high calorie and some oilness and oily odor still 
remain therein, as a result of satisfactorily reduced effect being not 
achieved by the prior method. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide fried instant noodles 
having much lower oil absorption, lower calories, much less oiliness and 
oily odor and good taste and texture, as compared with the prior fried 
instant noodles. Further, the present noodles can be reconstituted to a 
ready to eat state in a short time as the prior fried instant noodles can 
do. 
Another object of the invention is to provide a method for manufacturing 
such fried instant noodles. 
A further object of the invention is to provide a cereal flour mix 
composition suitable for the manufacture of the fried instant noodles 
having lower oil absorption, as outlined above. 
To achieve these objects, the present inventors conducted many repeated 
studies of the details of cereal raw materials used in the manufacture of 
fried instant noodles, of types of additives, and of noodle manufacturing 
methods, frying methods and the like. As a result, it was found that when 
noodle strings containing a chemical leavening agent and at least one 
enzyme selected from the group consisting of amylase and protease are 
prepared, steamed and then fried, the resulting fried instant noodles are 
of greatly reduced oil absorption, extremely low calories, a very low 
oiliness and oily odor, and superior gastronomical texture and taste, in 
comparison with the case of the prior art using the chemical leavening 
agent alone. It was also found that the present fried instant noodles can 
be restored to a ready to eat state in a short time, as the prior fried 
instant noodles can do. 
Thus, the present invention provides a method for manufacturing fried 
instant noodles wherein noodle strings containing a chemical leavening 
agent and at least one enzyme selected from the group consisting of 
amylase and protease are steamed and then fried. 
The present invention also includes fried instant noodles manufactured by 
this method. 
The present invention also provides a cereal flour mix composition for 
fried instant noodles which comprises cereal flours, a chemical leavening 
agent and at least one enzyme selected from the group consisting of 
amylase and protease.

DETAILED DESCRIPTION OF THE INVENTION 
In the manufacture of the fried instant noodles, the present invention can 
employ process steps of steaming the noodle strings followed by frying, 
which have been usually employed for the fried instant noodles. However, 
the present invention further requires that the noodle strings should 
contain at least one enzyme selected from the group consisting of amylase 
and protease, together with a chemical leavening agent. 
Any chemical leavening agent approved as a food additive can be used in the 
present invention, which undergoes a chemical reaction and/or 
decomposition at the heating temperature in the steaming process and/or 
the frying process of the noodle strings, in particular, at the heating 
temperature in the steaming process, thereby to produce carbon dioxide gas 
or other gas. Examples of chemical leavening agents which can be used in 
the invention include at least one gas generating agent such as sodium 
hydrogen carbonate, ammonium carbonate, ammonium dicarbonate, potassium 
carbonate, and the like; and a mixture of the above gas generating agents 
with one or more gas generating promotion agents such as tartaric acid, 
potassium hydrogen tartrate, fumaric acid, sodium fumarate, glucono 
delta-lactone, calcium primary phosphate, sodium phosphate, anhydrous 
ammonium aluminum chloride (burnt ammonium alum), anhydrous potassium 
aluminum sulfate (burnt alum), disodium dihydrogen pyrophosphate and the 
like. A combination of sodium hydrogen carbonate with glucono 
delta-lactone or burnt ammonium alum is preferably used from the aspects 
of volume of gas generated and taste. 
For the purpose of manufacturing fried instant noodles with low oil 
absorption and superior gastronomical texture and taste, it is desirable 
to prepare the noodle strings by adding the chemical leavening agent in an 
amount of 0.5 to 5 parts by weight (this being the total amount when more 
than one chemical leavening agent are used together), more preferably 1 to 
2 parts by weight based on 100 parts by weight of the cereal flours used 
to make the noodle strings. With less than 0.5 part by weight, no 
reduction of absorbed oil is obtained in the fried instant noodles. With 
more than 5 parts by weight, the amount of oil absorbed in the fried 
instant noodles is not greatly reduced, but a harsh taste or abnormal 
taste is produced from using the large amount of chemical leavening agents 
so that the taste of the fried instant cooking noodles deteriorates. 
As outlined above, the present invention requires that the noodle strings 
must contain at least one enzyme selected from the group consisting of 
amylase and protease, in addition to the chemical leavening agent. 
It is not evident why fried instant noodles with a very reduced amount of 
oil absorption can be produced by the present invention using at least one 
of the above enzymes together with a chemical leavening agent, in contrast 
with the prior art using the chemical leavening agent alone. This will be 
presumed as mentioned below. 
When the steamed noodles are fried in oil, the moisture contained in the 
noodle string vaporizes suddenly and the noodle string expands excessively 
into a porous structure. Oil is incorporated in the voids of the porous 
structure, which results in instant noodles with a high oil content. 
According to the present invention, however, the raw cereal flour is 
digested under the action of the enzyme in the preparation of the noodle 
dough, so that the dough is softened. When the noodle string obtained from 
the softened dough is steamed, the interior and the surface of the noodle 
string will expand more uniformly and minutely than the case of using the 
chemical leavening agent alone, thus forming into a moderate porous 
condition. When the moisture in the noodle string vaporizes off in the 
step of frying, the moderate porous structure having many passages for the 
vapor to escape can inhibit excessive expanding during the frying process. 
Thus, the volume of the voids in the noodle string will be reduced, so 
that the amount of oil incorporated in these voids is reduced, which can 
provide the reduced oil absorption as in the present invention. 
The enzyme used in the present invention may be a pure material or any food 
material containing at least one of the above-mentioned enzymes. Examples 
of the food materials can include malt, wheat germ or the like. 
To produce fried instant noodles with a low oil absorption and superior 
gastronomical texture and taste, the amount of enzyme used is preferably 
in the range of 0.05 to 100 U of enzyme activity (total activity for the 
combined use of the plural enzymes), more preferably, 0.1 to 50 U for 1 g 
of cereal flour used to make the noodle string. The activity (U) of the 
enzyme (amylase or protease) as defined here refers to the activity (U) 
measured by the method stated in the following examples. 
Representative processes for manufacturing noodle strings can include the 
following: 
(1) a method wherein raw materials for noodles are kneaded to make a dough, 
the dough is compounded and rolled into a sheet and this sheet is cut into 
noodle strings; and 
(2) an extrusion method wherein raw materials for noodles are kneaded in 
the same manner as for pasta and the resulting dough is extruded into 
noodle strings using an extruder. 
No limitation is made in the present invention on the method for producing 
the noodle strings which has not been subjected to steaming. Either the 
above method (1) or the above method (2) may be used. Depending on 
circumstances, the noodle strings may be produced by other methods than 
the above methods (1) and (2), e.g., a manual rolling method, a vacuum 
extrusion method or the like. No particular limitation is made in the 
present invention as to the processes and conditions for kneading; for 
compounding and rolling; for cutting the noodle strings; and for extruding 
the noodle strings or as to the type of equipment used for those 
processes. Those processes can be carried out in accordance with known 
processes depending on the type of noodle. 
In the steaming process of the noodle strings, they are preferably in the 
raw state or half-dried to such a degree that the chemical leavening agent 
and enzyme contained in the noodle string do not lose their activity. This 
is desirable in that the subsequent steaming of the noodle strings can be 
performed smoothly and fried instant noodles with low oil absorption can 
be obtained. 
So long as the chemical leavening agent and the enzyme are mixed uniformly 
in the noodle strings, no particular restriction is made in the present 
invention on the method of adding them. The noodle strings containing the 
chemical leavening agent and enzyme can be manufactured, for example, by 
1! a method of adding the chemical leavening agent and enzyme to the 
cereal flours for the production of the noodles, optionally together with 
other ingredients, further adding water, kneading the mixture to form a 
dough and producing the noodle strings from the dough according to the 
above-mentioned method (1) or (2) or other methods; or by 2! a method of 
adding other ingredients, as required, to the cereal flours for the 
manufacture of the noodles, further adding the chemical leavening agent 
and the enzyme dissolved in water, kneading the mixture to form a dough, 
and producing the noodle strings from the dough according to the 
above-mentioned method (1) or (2) or other methods. In either case, it is 
desirable that the chemical leavening agent and enzyme are added prior to 
kneading the dough or at the start of the kneading step, since the 
chemical leavening agent and enzyme can be uniformly dispersed in the 
dough and the softening of the dough proceeds to produce fried instant 
noodles with low oil absorption. 
A dry cereal flour mix composition obtained by adding the chemical 
leavening agent and enzyme to the cereal flours for the manufacture of the 
noodles and further adding other ingredients, as required, can be 
distributed and sold as a cereal flour mix composition for fried instant 
noodles. 
Thus, the present invention also provides a cereal flour mix composition 
for fried instant noodles, which comprises cereal flours, a chemical 
leavening agent and at least one enzyme selected from the group consisting 
of amylase and protease, and optionally other components. 
The thickness, width, diameter and the like of the noodle string can be 
adjusted depending on the type of fried instant noodles and the like. In 
general, a noodle string with the thickness of about 0.7 to 1.6 mm and the 
width of about 1.0 to 2.0 mm, or a noodle string with the diameter of 
about 0.9 to 1.5 mm is preferred in that the subsequent steaming and 
frying can be carried out smoothly and the resulting fried instant noodles 
can exhibit reduced oil absorption. 
Any cereal flour conventionally used in the manufacture of noodles can be 
used, examples of which include wheat flour, durum wheat flour, rye flour, 
soybean flour, oat flour, buckwheat flour, rice flour; starches such as 
potato starch, tapioca starch, corn starch and the like; the alpha 
converted form of these cereal flours; dogtooth violet starch; yam starch 
and the like. These cereal flours may be used alone or in admixture 
therewith. The cereal flour may be selected depending on the variety of 
noodle to be manufactured. 
In addition to cereal flours, chemical leavening agents and enzymes, one or 
more additives and raw materials as used hitherto may be used depending on 
the type of fried instant noodle. Examples of such additives and raw 
materials include "Kansui", salt, emulsifying agents, protein enhancing 
agents, polysaccharides for increasing viscosity, oligosaccharides, 
polymerized phosphates, coloring materials, nutrition enhancing agents, 
powdered chlorella, powdered skim milk, powdered vegetables, powdered 
seaweeds, antioxidants, whole egg, egg white and the like. 
The noodle strings containing a chemical leavening agent and enzyme 
manufactured as described above are subjected to a steaming. The steam 
temperature is preferably in range of 95-100.degree. C. When a noodle 
string is steamed in the above steam temperature range, only the surface 
of the noodle string is normally gelatinized. Upon steaming of the noodle 
strings, part or all of the leavening agent undergo a decomposition or a 
chemical reaction to generate gas, so that the noodle string expands and 
the surface and inside of the noodle string becomes a porous structure. In 
this case, the expanding of the noodle string is inadequate if the 
chemical leavening agent is used alone. In the present invention, at least 
one enzyme selected from the group consisting of amylase and protease is 
used together with a chemical leavening agent. Thus, the ability of 
trapping the gas is improved as a result of the softness of the noodle 
string (dough) caused by these enzymes, so that the expanding of the 
noodle string is more accelerated at the surface and inside thereof and a 
uniform porous structure is created. As a result, the drying of the 
expanded noodle string is performed more smoothly and swiftly in the 
subsequent frying process so that a fried instant noodle with a greatly 
reduced oil absorption is obtained. 
There is no particular restriction on the steaming process for the noodle 
strings. Any process and apparatus conventionally used in the steaming of 
instant noodles can be employed. For example, the noodle strings are 
processed with steam at a temperature of 95.degree. C. to 100.degree. C. 
until the moisture content is reached to the extent of 28 to 35 wt %, 
while transferring continuously the noodle strings on a net conveyor or 
the like, or by packing the noodle strings in a basket or the like and 
placing in a batch-wise, steam chamber. 
Subsequently, the steamed noodles are fried in the same manner as in 
manufacturing conventional fried instant noodles, while disentangling the 
steamed noodle strings. For example, each single serving or several 
servings are filled into a retainer, a frame or the like to provide one 
package noodle, and the one package noodle is fried and dehydrated to 
manufacture the fried instant noodles. In this case, the frying of the one 
package noodle may be performed using the same method and equipment as 
used for manufacturing conventional fried instant noodles. This frying 
process is not limited. Generally, edible oils such as palm oil, partially 
hydrogenated palm oil, pure lard, modified lard, and mixtures of these are 
used. The noodle strings are fried for about 1 to 3 minutes at 
temperatures of about 130-150.degree. C. 
The resulting fried noodles are cooled, packed, cartoned and encased in a 
conventional manner, and then can be stored, distributed and sold. 
By carrying out the series of processes as outlined above, fried instant 
noodles of the present invention are obtained, having lower oil 
absorption, a lower calorie content, a lower oily odor or oilness than the 
conventional product, and superior gastronomical taste and texture. The 
present noodles can also be restored to a ready to eat state in a short 
time. 
The kind of fried instant noodles manufactured by the present invention is 
not limited, examples of which can include Chinese-style noodles; 
Japanese-style noodles such as instant udon and instant soba; and 
European-style noodles. 
The fried instant noodles of the present invention may be flavored and 
seasoned, or alternatively accompanied by a packet of soup. 
The present invention is further illustrated by the following 
non-limitative examples, in which % is by weight unless otherwise stated. 
In the following examples, the activities of amylase and protease are 
measured in the following manner. 
Method of measuring activity of amylase 
(1) Preparation of substrate solution 
Potato starch (pharmaceutical grade) was dried for two hours at 105.degree. 
C. Precisely 1.000 g of this dried material was weighed out, 20 ml of 
water was added, and the mixture was thoroughly stirred using a stirrer, 
while 5 ml of a 1 N sodium hydroxide solution was added to make a paste. 
The paste-like material was heated for five minutes in a boiling water 
bath, then cooled by the addition of 25 ml of cold water. The pH was then 
adjusted to 7.0.+-.0.1 with a 1 N phosphoric acid solution. Twenty ml of a 
0.5 M phosphate buffer solution (pH 7.0) was then added, and the mixture 
was diluted to 100 ml with distilled water to complete the preparation of 
the substrate solution. 
(2) Preparation of 1/5000 N iodine solution 
Fifty grams of potassium iodide was dissolved in 100 ml of distilled water, 
then 12.69 g of iodine were added and completely dissolved, after which 
more distilled water was added to give a total volume of 1000 ml, 
completing the preparation of a 0.1 N iodine solution. This solution was 
stored in a brown bottle. Prior to use, a 1/5000 N iodine solution was 
prepared as follows. One ml of 0.1 N iodine solution was mixed with 10 ml 
of a 1 N hydrochloric acid solution and diluted to 500 ml with distilled 
water. 
(3) Measurement of absorbance 
(i) Ten ml aliquots of the substrate solution prepared as under (1) above 
were incubated in a water bath at 40+0.1.degree. C. for 10 to 15 minutes. 
One ml of enzyme solution was then added, the test tube was stoppered and 
shaken vigorously to thoroughly mix the contents, and immediately held at 
40.+-.0.1.degree. C. At exactly 10 min after the addition of the enzyme 
solution, one ml of this solution was measured out into 10 ml of 0.1 N 
hydrochloric acid solution which had previously been placed in a test tube 
(18 mm diameter, 180 mm length) equipped with a stopper. The test tube was 
then stoppered and well shaken. One ml of this liquid was added to 10 ml 
of the 1/5000 N iodine solution prepared under (2) above which had 
previously been placed in a test tube (18 mm diameter, 180 mm length) 
equipped with a stopper. This test tube was then stoppered and well 
shaken. The solution was then placed in a cell with a 10 mm optical path 
length and its absorbance (A.sub.1) was measured at a wave length of 660 
nm, with distilled water as a control. 
(ii) Using one ml of distilled water as a blank, in place of the enzyme 
solution, the absorbance (A.sub.0) was measured in the same manner as 
outlined in (i) above. 
(4) Preparation of enzyme solution 
Enzyme solutions were prepared by measuring out predetermined amounts of 
enzyme (amylase) used in the following examples and comparative examples, 
and dissolving these predetermined amounts in any suitable dilution liquid 
such as 50 mM tris-hydrochloric acid buffer solution (7.2 pH). The 
dilution ratio is such that (A.sub.0 -A.sub.1 )/A.sub.0 which is the 
decomposition ratio of each enzyme (amylase) is 0.2 to 0.4. 
(5) Calculation of enzyme activity 
One Unit (U) is the amount of enzyme which reduces the blue iodine coloring 
in starch by 1% in one minute under the above-mentioned conditions. 
Accordingly, the enzyme (amylase) activity (U)(Unit) is given by the 
following numerical formula. 
##EQU1## 
where A.sub.0 =absorbance of the blank 
A.sub.1 =absorbance of the enzyme decomposed substrate 
n=dilution ratio of the enzyme 
Method of measuring activity of protease 
(1) Preparation of substrate solution (milk casein solution) 
1.5 g of milk casein ("Hamersteine" manufactured by Merck) were weighed 
out, 25 ml of 0.1 N sodium hydroxide solution were added, and the mixture 
was held for 10 min in a hot water bath at 90-95.degree. C. to dissolve, 
then the solution was cooled with cold water. After cooling, 0.1 N 
phosphoric acid was added to adjust the pH to 7.0. In addition, 20 ml of 
0.1 M phosphoric acid buffer solution adjusted to a pH of 7 and cold water 
were added to give 100 ml of the prepared milk casein solution. 
(2) Preparation of reaction stop solution 
1000 ml of 0.4 M trichloroacetic acid solution were prepared by dissolving 
65.36 g of trichloroacetic acid in water. This solution was used as a 
reaction stop solution. 
(3) Preparation of enzyme solution (protease test solution) 
Enzyme solutions were prepared by dissolving 0.5 g of the enzyme (protease) 
used in the examples and comparative examples in 150 ml of any suitable 
dilution solution such as 50 mM tris-hydrochloric acid buffer solution 
(7.2 pH). One ml of this solution was then measured out and made up to 100 
ml using the same dilution liquid (30,000 times dilution) to give the 
enzyme solution. 
(4) Measurement of absorbance 
(i) One ml of the substrate solution (milk casein solution) prepared under 
(1) above was measured into a test tube (15 mm diameter, 150 mm length), 
placed in a constant temperature water bath at 37.+-.0.5.degree. C., and 
preheated for 5 min. Exactly 1 ml of the enzyme solution (protease test 
solution) prepared under (3) above was added and well shaken, the test 
tube was placed in the constant temperature water bath at 
37.+-.0.5.degree. C. and held for 60 min. Two ml of the reaction stop 
solution prepared under (2) above were added and well shaken, the test 
tube was placed in the constant temperature water bath at 
37.+-.0.5.degree. C. and held for 25 min. The solution was then filtered 
using a No. 131 filter paper (7 cm diameter). One ml of the filtrate was 
measured into a test tube (18 mm diameter, 180 mm length), after which 5 
ml of 0.4 M sodium carbonate solution and 1.0 ml of Folin-Ciocalteau's 
reagent ("Phenol reagent" manufactured by Wako Junyaku Kogyo, K. K.) 
diluted five times with distilled water were added. The mixture was 
thoroughly shaken to mix, then placed in the constant temperature water 
bath at 37.+-.0.5.degree. C. and held for 20 min for color to develop. 
After the color had developed, the absorbance (A.sub.t) was measured at a 
wave length of 660 nm, with distilled water as a control. 
(ii) Separately, as a blank test, one ml of the substrate solution (milk 
casein solution) prepared under (1) above was measured into a test tube 
(15 mm diameter, 150 mm length), 2 ml of 0.4 M trichloroacetic acid 
solution were added, and the mixture was thoroughly shaken to mix. Exactly 
1 ml of distilled water was added and well shaken, the test tube was 
immediately placed in the constant temperature water bath at 
37.+-.0.5.degree. C. and held for 60 min. Two ml of the reaction stop 
solution prepared under (2) above were then added and well shaken, the 
test tube was placed in the constant temperature water bath at 
37.+-.0.5.degree. C. and held for 25 min. The solution was then filtered 
using a No. 131 filter paper (7 cm diameter). One ml of the filtrate was 
measured into a test tube (18 mm diameter, 180 mm length), after which 5 
ml of 0.4 M sodium carbonate solution and 1.0 ml of Folin-Ciocalteau's 
reagent ("Phenol reagent" manufactured by Wako Junyaku Kogyo, K.K.) 
diluted five times with distilled water were added. The mixture was 
thoroughly shaken to mix, then placed in the constant temperature water 
bath at 37.+-.0.5.degree. C. and held for 20 min for color to develop. 
After the color had developed, the absorbance (A.sub.0) was measured at a 
wave length of 660 nm, with distilled water as a control. 
(iii) Preparation of tyrosine calibration curve 
Standard tyrosine was dried for 3 hours at 105.degree. C., then 0.100 g 
were accurately weighed out and dissolved in 0.1 N hydrochloric acid 
solution to give a volume of exactly 100 ml. Volumes of exactly 1 ml, 2 
ml, 3 ml, 4 ml and 5 ml of this solution were measured out, and 0.1 N 
hydrochloric acid solution was added to each of these portions to bring 
the volume up to exactly 100 ml. One ml of these solutions then contained 
10 .mu.g, 20 .mu.g, 30 .mu.g, 40 .mu.g, and 50 .mu.g respectively of 
tyrosine. Subsequently, one ml of each of these solutions was accurately 
measured out, then 5 ml of 0.4 M sodium carbonate solution and 1.0 ml of 
Folin-Ciocalteau's reagent ("Phenol reagent" manufactured by Wako Junyaku 
Kogyo, K.K.) diluted five times with distilled water were added to each. 
The mixtures were thoroughly shaken to mix, then placed in the constant 
temperature water bath at 37.+-.0.5.degree. C. and held for 20 min for 
color to develop. After the color had developed, the absorbances A.sub.1, 
A.sub.2, A.sub.3, A.sub.4, and A.sub.5 were measured at a wave length of 
660 nm, with distilled water as a control. Separately, the absorbance 
A.sub.0 was measured for a solution made up by the same method using 1 ml 
of 0.1 N hydrochloric acid solution in place of the tyrosine standard 
solution. From these results, a calibration curve was prepared by plotting 
the weight of tyrosine (.mu.g) contained in one ml of these various 
solutions as abscissa and the absorbance differences A.sub.1 -A.sub.0, 
A.sub.2 -A.sub.0, A.sub.3 -A.sub.0, A.sub.4 -A.sub.0, and A.sub.5 -A.sub.0 
! as ordinate. The tyrosine (F .mu.g) corresponding to an absorbance 
difference of 1.000 was thus obtained. 
(5) Calculation of protease activity 
One Unit (1 U) of protease strength is defined as the amount of enzyme 
which produces amino acid corresponding to 100 .mu.g of tyrosine in 1 ml 
of the reaction filtrate for 60 min. The protease activity is calculated 
by the following numerical formula. 
EQU Protease activity (U/g)={(A.sub.t -A.sub.0).times.F.times.1/100.times.n 
where 
A.sub.0 =absorbance of the blank 
A.sub.t =absorbance of the enzyme decomposed substrate 
F=amount of tyrosine (.mu.g) when the absorbance difference is 1.000, 
obtained from the tyrosine calibration curve 
n=dilution ratio of the test solution 
EXAMPLE 1 
(1) 1.0 part by weight of a chemical leavening agent with the composition 
shown in the following Table 1 (powder type synthetic chemical leavening 
agent manufactured by Oriental Yeast Co., Ltd.) and the amount of amylase 
(Amylase AD "Amano" manufactured by Amano Pharmaceutical Co., Ltd.) shown 
in the following Table 3 were added to 100 parts by weight of hard wheat 
flour ("TOKU NUMBER ONE" manufactured by Nisshin Flour Milling Co., Ltd.). 
In addition, 29 parts by weight of an aqueous solution of one part by 
weight of salt and 0.2 parts by weight of "Kansui" in 27.8 parts by weight 
of water were added to the above and the mixture was kneaded for 10 min by 
a conventional method to produce a dough. Then, this dough was rolled by a 
conventional method using noodle-making rolls to give a sheet of 1.0 mm 
thickness. The sheet was then cut into noodle strings using a pair of No. 
20 cutting rolls. 
(2) The respective noodle strings obtained in (1) above were placed in 
steaming baskets and steamed for 3 min at a steam temperature of 
100.degree. C., discharged from the steaming basket, and fried for 80 sec 
in refined palm oil at 135.degree. C. to 140.degree. C., to manufacture 
various Chinese fried instant noodles. 
TABLE 1 
______________________________________ 
Chemical leavening agent composition 
______________________________________ 
Potassium aluminum sulfate 
8.8 wt % 
Calcium dihydrogen phosphate 
8.9 wt % 
Calcium hydrogen phosphate 
1.1 wt % 
Fumaric acid 2.7 wt % 
Disodium dihydrogen pyrophosphate 
13.2 wt % 
Glucono delta-lactone 
16.0 wt % 
Sodium hydrogen carbonate 
40.0 wt % 
Starch 9.3 wt % 
Total 100.0 wt % 
______________________________________ 
(3) Using part of the steamed noodles and the fried Chinese instant noodles 
obtained in (2) above, the oil absorption ratio and oil absorption 
reduction ratio of the Chinese fried instant noodles were measured in the 
following manner. The results are shown in Table 3. 
Oil absorption ratio of fried instant noodles 
(i) The fried instant noodles were allowed to cool and the weight (W) (g) 
was measured. 
(ii) The cooled fried instant noodles were dried for 2 hr at 135.degree. C. 
to determine the moisture content (M.sub.1) (%). Using this value of the 
moisture content, the dry weight (Wi) (g) of the fried instant noodles for 
which the weight (W) had been measured in (i) above was calculated. 
(iii) The weight (Wii) (g) of the steamed noodles obtained under (2) above 
was measured after cooling but prior to frying. The moisture was removed 
by drying for one hour at 135.degree. C. and the moisture content 
(M.sub.2) (%) was determined. Using this value of the moisture content, 
the dry weight (Ws) (g) of the steamed noodles corresponding to the fried 
instant noodles for which the weight (W) had been measured in (i) above 
was obtained by the numerical formula given below. 
(iv) From the weight (W) (g) of the fried instant noodles, the dry weight 
(Wi) (g) of the fried instant noodles and the dry weight (Ws) (g) of the 
steamed noodles obtained as above, the oil absorption ratio of the fried 
instant noodles was calculated using the following formulae. 
EQU Dry weight of fried instant noodles (Wi) (g)=W.times.{1-(M.sub.1 /100)} 
EQU Dry weight of steamed noodles (Ws) (g)=Wii.times.{1-(M.sub.2 /100)} 
EQU Oil absorption ratio (%) of fried instant noodles={(Wi-Ws)/W}.times.100 
Oil absorption reduction ratio 
With the oil absorption ratio of fried instant noodles obtained from noodle 
strings which contain neither a chemical leavening agent nor an enzyme 
(the fried instant noodles of Test No. 1 of Example 1 and Test No. 11 of 
Example 2) as the criterion, the oil absorption reduction ratio of the 
fried instant noodles obtained from Test Nos. 2 to 10 of Example 1, Test 
Nos. 12 to 20 of Example 2, and Examples 3 to 9 were obtained using the 
following numerical formula. 
EQU Oil absorption reduction ratio (%)={(A-B/A)}.times.100 
wherein 
A=oil absorption ratio (%) of fried instant noodles obtained form noodle 
strings which contain neither a chemical leavening agent nor an enzyme 
B=oil absorption ratio (%) of fried instant noodles obtained from noodle 
strings containing one or both of a chemical leavening agent and an enzyme 
(4) Furthermore, 100 g of each of the respective Chinese fried instant 
noodles obtained in (2) above were reconstituted by immersion for 3 min in 
600 ml boiling water. These reconstituted noodles were subjected to 
organoleptic testing by a panel of 10 members according to the evaluation 
criteria shown in the following Table 2. The average values of these 
organoleptic tests are given in Table 3. The organoleptic tests were also 
conducted on the Chinese fried instant noodles of Test No. 1 of Example 1 
and Test No. 11 of Example 2, produced using noodle strings containing 
neither a chemical leavening agent nor an enzyme, as a control 
(three-point as a standard). 
TABLE 2 
Criteria for organoleptic evaluation of fried instant noodles 
Degree of elasticity 
5: Very good, good degree of elasticity, as compared with control 
4: Good, proper degree of elasticity, as compared with control 
3: Same degree of elasticity as control 
2: Slightly inferior degree of elasticity, slightly soft or slightly hard, 
as compared with control 
1: Poor degree of elasticity, extremely soft or extremely hard, as compared 
with control 
Degree of smoothness 
5: Very good; very superior smoothness, as compared with control 
4: Good; superior smoothness, as compared with control 
3: Same degree of smoothness as control 
2: Poor; inferior degree of smoothness, as compared with control 
1: Very poor; smoothness much less than control 
Oily odor, oiliness and taste 
5: Good taste; oily odor and oiliness much reduced, as compared with 
control 
4: Fairly good taste; oily odor and oiliness slightly reduced, as compared 
with control 
3: Oily odor, oiliness and taste same as control 
2: Slightly inferior taste; oily odor and oiliness slightly increased, as 
compared with control 
1: Poor taste; oily odor and oiliness much increased, as compared with 
control 
TABLE 3 
__________________________________________________________________________ 
Ratio of Oil 
Chemical Oil absorp- 
Organoleptic tests for fried 
leaven- absorp- 
tion instant noodles 
ing agent 
Ratio of enzyme 
tion 
reduc- 
Degree Oily odor, 
Test 
added.sup.1) 
added.sup.2) 
ratio 
tion of elas- 
Smooth- 
oiliness 
No. 
(%) (%) (%) ratio (%) 
ticity 
ness and taste 
__________________________________________________________________________ 
1 0 0 (0 U) 
21.0 
0.0 3.0 3.0 3.0 
2 2 0 (0 U) 
19.3 
8.1 3.0 3.0 3.0 
3 2 5 .times. 10.sup.-4 
(0.05 U) 
18.3 
12.9 3.0 3.2 3.4 
4 2 1 .times. 10.sup.-3 
(0.10 U) 
17.8 
15.2 3.0 3.2 4.0 
5 2 1 .times. 10.sup.-2 
(1 U) 
17.2 
18.1 3.0 3.4 4.0 
6 2 1 .times. 10.sup.-1 
(10 U) 
16.6 
21.0 3.0 3.5 4.3 
7 2 2 .times. 10.sup.-1 
(20 U) 
15.5 
26.2 3.0 3.4 4.4 
8 2 5 .times. 10.sup.-1 
(50 U) 
14.7 
30.0 3.0 3.4 4.1 
9 2 1 (100 U) 
14.3 
31.9 3.0 3.4 3.6 
10 2 2 (200 U) 
15.0 
28.6 2.2 3.4 3.4 
__________________________________________________________________________ 
.sup.1) Ratio of the chemical leavening agent added (wt %) based on weigh 
of wheat flour 
.sup.2) Ratio of the enzyme added (wt %) based on weight of wheat flour 
(Figures in brackets indicate enzyme activity (U) added to 1 g of wheat 
flour.) 
As can be seen from the results shown in Table 3, in the cases of the fried 
instant noodles of Test No. 1 obtained using noodle strings containing 
neither amylase nor a chemical leavening agent and the fried instant 
noodles of Test No. 2 obtained using noodle strings containing a chemical 
leavening agent but not amylase, the oil absorption ratio is larger and 
the calorie content is higher, an oily odor and oiliness are present, and 
the taste is inferior, in comparison with the fried instant noodles 
obtained from Test Nos. 3 to 10 obtained using noodle strings containing 
both a chemical leavening agent and amylase. 
In addition, the results shown in Table 3 show that it is desirable that 
the amount of enzyme (amylase) contained in the noodle strings be 0.05 to 
100 U, and more preferably be 0.1 to 50 U, for one gram of wheat flour 
used in the noodle strings. 
EXAMPLE 2 
(1) With the exception of 0.2 parts by weight of the same amylase used in 
Example 1 (amylase activity=20 U for 1 g of wheat flour) and the same 
amounts as shown in Table 4 of the chemical leavening agent used in 
Example 1 being added to 100 parts by weight of the same wheat flour used 
in Example 1, the respective fried instant noodles were manufactured in 
exactly the same manner as in Example 1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 4. 
TABLE 4 
__________________________________________________________________________ 
Ratio of Oil 
Chemical Oil absorp- 
Organoleptic tests for fried 
leaven- absorp- 
tion instant noodles 
ing agent 
Ratio of enzyme 
tion 
reduc- 
Degree Oily odor, 
Test 
added.sup.1) 
added.sup.2) 
ratio 
tion of elas- 
Smooth- 
oiliness 
No. 
(%) (%) (%) ratio (%) 
ticity 
ness and taste 
__________________________________________________________________________ 
11 0 0 (0 U) 
21.0 
0.0 3.0 3.0 3.0 
12 0 0.2 
(20 U) 
19.5 
7.1 3.0 3.1 3.0 
13 0.4 0.2 
(20 U) 
18.9 
10.0 3.0 3.1 3.1 
14 0.5 0.2 
(20 U) 
17.8 
15.2 3.0 3.2 3.3 
15 1 0.2 
(20 U) 
16.4 
21.9 3.0 3.4 4.4 
16 2 0.2 
(20 U) 
15.5 
26.2 3.0 3.4 4.4 
17 3 0.2 
(20 U) 
15.7 
25.2 3.0 3.4 3.4 
18 5 0.2 
(20 U) 
15.6 
25.7 3.0 3.1 3.2 
19 6 0.2 
(20 U) 
15.8 
24.8 2.9 3.0 2.8 
20 10 0.2 
(20 U) 
16.8 
20.0 2.0 2.4 2.0 
__________________________________________________________________________ 
.sup.1) Ratio of the chemical leavening agent added (wt %) based on weigh 
of wheat flour 
.sup.2) Ratio of the enzyme added (wt %) based on weight of wheat flour 
(Figures in brackets indicate enzyme activity (U) added to 1 g of wheat 
flour.) 
As can be seen from the results shown in Table 4, in the cases of the fried 
instant noodles of Test No. 11 obtained using noodle strings containing 
neither amylase nor a chemical leavening agent and the fried instant 
noodles of Test No. 12 obtained using noodle strings containing amylase 
but not a chemical leavening agent, the oil absorption ratio is larger and 
the calorie content is higher, an oily odor and oiliness are present, and 
the taste is inferior, in comparison with the fried instant noodles 
obtained from Test Nos. 13 to 20 obtained using noodle strings containing 
both a chemical leavening agent and amylase. 
In addition, the results shown in Table 4 show that it is desirable that 
the amount of the chemical leavening agent contained in the noodle strings 
be 0.5 to 5 wt % (0.5 to 5 parts by weight of the chemical leavening agent 
to 100 parts by weight of wheat flour) and more preferably be 1 to 2 wt %, 
based on the amount of wheat flour used in the noodle strings. 
EXAMPLE 3 
With the exception of the addition of one part by weight of another amylase 
("Takadiastase" manufactured by Sankyo Co., Ltd.) (amylase activity=50 U 
for 1 g of wheat flour) instead of the amylase AD "Amano", and one part by 
weight of the same chemical leavening agent used in Example 1, and the 
addition of 30 parts by weight of an aqueous solution of 0.2 parts by 
weight of "Kansui" and one part by weight of salt in 28.8 parts by weight 
of water to 100 parts by weight of the same wheat flour used in Example 1, 
the fried instant noodles were manufactured in exactly the same manner as 
in Example 1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
EXAMPLE 4 
With the exception of the addition of 0.05 part by weight of another 
amylase (Ekikakouso T manufactured by Hankyu Bio Industry Co., Ltd.) 
(amylase activity=5 U for 1 g of wheat flour) instead of the amylase AD 
"Amano", and one part by weight of the same chemical leavening agent used 
in Example 1, to 100 parts by weight of the same wheat flour used in 
Example 1, the fried instant noodles were manufactured in exactly the same 
manner as in Example 1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
EXAMPLE 5 
With the exception of the addition of 0.2 part by weight of another amylase 
("Sumichyme L" manufactured by Shin Nippon Chemical Industry Co., Ltd.) 
(amylase activity=24 U for 1 g of wheat flour) instead of the amylase AD 
"Amano", and one part by weight of the same chemical leavening agent used 
in Example 1, to 100 parts by weight of the same wheat flour used in 
Example 1, the fried instant noodles were manufactured in exactly the same 
manner as in Example 1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
EXAMPLE 6 
With the exception of the addition of 0.02 parts by weight of protease 
(Protease M "Amano" manufactured by Amano Pharmaceutical Co., Ltd.) 
(protease activity=1 U for 1 g of wheat flour) instead of amylase, and one 
part by weight of the same chemical leavening agent used in Example 1, to 
100 parts by weight of the same wheat flour used in Example 1, the fried 
instant noodles were manufactured in exactly the same manner as in Example 
1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
EXAMPLE 7 
With the exception of the addition of 0.18 parts by weight of protease 
(Protease M "Amano" manufactured by Amano Pharmaceutical Co., Ltd.) 
(protease activity=10 U for 1 g of wheat flour), the fried instant noodles 
were manufactured in exactly the same manner as in Example 6. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
EXAMPLE 8 
With the exception of the addition of 0.1 part by weight of protease 
(Protease A "Amano" manufactured by Amano Pharmaceutical Co., Ltd.) 
(protease activity=10 U for 1 g of wheat flour) instead of amylase, and 
one part by weight of the same chemical leavening agent used in Example 1, 
to 100 parts by weight of the same wheat flour used in Example 1, the 
fried instant noodles were manufactured in exactly the same manner as in 
Example 1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
EXAMPLE 9 
With the exception of the addition of 0.01 part by weight of protease 
(Protease N "Amano" manufactured by Amano Pharmaceutical Co., Ltd.) 
(protease activity=15 U for 1 g of wheat flour) instead of amylase, and 
one part by weight of the same chemical leavening agent used in Example 1, 
to 100 parts by weight of the same wheat flour used in Example 1, the 
fried instant noodles were manufactured in exactly the same manner as in 
Example 1. 
The oil absorption ratio of the resulting fried instant noodles was 
obtained in the same manner as in Example 1, and 100 g of the resulting 
Chinese fried instant noodles were immersed in 600 ml of boiling water for 
3 min to reconstitute the noodles. These noodles were subjected to the 
same organoleptic evaluation as in Example 1. The results are shown in 
Table 5. 
TABLE 5 
__________________________________________________________________________ 
Ratio of Oil 
chemical Oil absorp- 
Organoleptic tests for fried 
leaven- absorp- 
tion instant noodles 
Exam- 
ing agent tion 
reduc- 
Degree Oily odor, 
ple added.sup.1) 
Enzyme ratio 
tion of elas- 
Smooth- 
oiliness 
No. (%) Type % Added.sup.2) 
(%) ratio (%) 
ticity 
ness and taste 
__________________________________________________________________________ 
3 1 Takadiastase 
1 (50 U) 
15.7 
25.2 3.2 3.2 4.5 
4 1 Ekikakouso T 
0.05 
(5 U) 
17.4 
17.1 3.0 3.3 4.0 
5 1 Sumichyme L 
0.2 
(24 U) 
15.5 
26.2 3.3 3.3 4.5 
6 1 Protease M 
0.02 
(1 U) 
16.9 
19.5 3.1 3.2 4.1 
"Amano" 
7 1 Protease M 
0.18 
(10 U) 
16.1 
23.3 3.0 3.3 4.5 
"Amano" 
8 1 Protease A 
1.0 
(10 U) 
16.8 
20.0 3.0 3.2 4.1 
"Amano" 
9 Protease N 
0.01 
(15 U) 
17.2 
18.1 3.0 3.2 4.1 
1 "Amano" 
__________________________________________________________________________ 
.sup.1) Ratio of the chemical leavening agent added (wt %) based on weigh 
of wheat flour 
.sup.2) Ratio of each enzyme added (wt %) based on weight of wheat flour 
(Figures in brackets indicate enzyme activity (U) added to 1 g of wheat 
flour.) 
As can be seen from the results shown in Table 5, in all of the fried 
instant cooking noodles of Examples 3 to 9 obtained by steaming and frying 
the noodle strings containing either amylase or protease and a chemical 
leavening agent, the oil absorption ratio is small and the calorie content 
is low, there is no oily odor or oiliness present, and the gastronomical 
taste and texture are superior. 
The fried instant noodles of the present invention exhibit an extremely low 
oil absorption when fried, which results in a low calorie content and 
preveting too much fats and oils from being taken up. In addition, there 
is very little oily odor or taste and the gastronomical flavor and texture 
are superior. Furthermore, the noodles can be reconstituted to a ready to 
eat state in a short time and the reconstituted noodles exhibit a superior 
smoothness and gastronomical texture.