JP2952188B2 - Method for producing low protein rice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing low protein rice.

[0002]

2. Description of the Related Art The number of kidney disease patients is said to be 600,000 to 700,000 nationwide, and tends to increase year by year. Due to the reduced ability of the kidney to metabolize proteins, patients with kidney disease have severe dietary restrictions and a limited daily intake. For example, the amount of protein suitable for daily consumption by an adult male is about 70 g, while that of a kidney disease patient must be 35 g or less, which is less than half that of an adult male.

[0003] By the way, the amount of protein for one meal of ordinary rice is about 5 g.
g. For this reason, even eating only rice is very burdensome for kidney disease patients. Such diets for patients with kidney disease require a diet that reduces protein and does not impair other nutrients.

[0004] For this reason, rice, which is the staple food,
Research on protein reduction for patients with kidney disease has been conducted. For example, a protein that is abundant on the surface of rice
After gelatinizing the specially milled rice and starch which have been scraped about 0%,
BACKGROUND ART Artificial rice produced by a process of molding and drying rice grains is known.

[0005] Japanese Patent Application Laid-Open No. Hei 6-217719 discloses a method for reducing protein in rice using lactic acid bacteria.
Rice obtained by such a method is aseptically packed and sold under the trade name of "Hanyu Yumegohan" or "Hikari".

Further, Japanese Patent Application Laid-Open No. 2-167040 discloses a method for producing low allergen rice by treating globulin contained in rice with a protease and reducing globulin content.

[0007] However, it is difficult to eat cooked rice, which is small rice grain and artificial rice, is small in grain size, close to starch grain, has poor rice-cooking characteristics, and has a good texture. In order to reduce protein using lactic acid bacteria, it is necessary to use rice having a strict range of rice milling degree of 88 to 89%, and it takes six days to reduce protein. In addition, there is a problem that dried rice having a low protein content is easily broken. In addition, when cooking the obtained rice, it is necessary to steam it once before cooking, and it is very difficult to eat cooked rice with a good texture in the same way as regular rice. is there.

[0008] The method for producing low allergen rice is developed for the purpose of rice allergy patients, the amount of protein has not been reduced to less than 1/2, and so called low protein rice for kidney disease patients. Absent. In addition, the enzyme reaction temperature for allergen reduction is 37 ° C., and a complicated treatment of using a surfactant is required, which increases the cost. Moreover, the method of cooking rice becomes complicated.

As described above, in order to reduce the protein content of rice by the conventional method, it is necessary to carefully select the rice and to perform the treatment in a complicated process. In addition, the protein content of the reduced protein rice is large. Since the surface layer of rice is destroyed, it has high water absorption and cannot cook cooked rice having a good texture with a normal rice cooking method.

[0010]

DISCLOSURE OF THE INVENTION The present invention can reduce the amount of protein in uncooked rice by a simple processing step, has a transparent color close to that of uncooked rice, has a property that is hard to be broken, and has an advantage in washing rice. It is intended to provide a method for producing low-protein rice that can cook rice in a microwave or a microwave oven in the same manner as ordinary rice without eating, and can eat cooked rice with a good texture. .

[0011]

The method for producing low protein rice according to the present invention comprises: converting an uncooked rice to an acidic side to adjust a reaction optimum pH.
45 to 7 in the presence of a thermostable proteolytic enzyme
Carrying out an enzyme treatment at a temperature of 0 ° C. to reduce protein;
A step of drying the low-protein uncooked rice to reduce the water content to 25 to 40% by weight; and a step of heating the dried uncooked rice so that the cooking value (C value) becomes 6 minutes or more. And a step of processing.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing low protein rice according to the present invention will be described in detail. (First Step) First, uncooked rice is enzymatically treated at a temperature of 45 to 70 ° C. in the presence of a heat-resistant protease to reduce protein.

As the uncooked rice, any glutinous rice such as Kirara, Sasanishiki and Koshihikari can be used. As the proteolytic enzyme having the optimum pH on the acidic side , for example, peptidase R (trade name, manufactured by Amano Pharmaceutical Co., Ltd.) can be used. The pH of the solution containing the enzyme is preferably adjusted to 4 to 5 on the acidic side.

The buffer for dissolving the proteolytic enzyme is not particularly limited as long as it can be used for food and does not contain phosphorus or potassium, which is not ingested by kidney disease patients. Is preferably a citrate buffer or an acetate buffer, and a glycine buffer is suitable for an enzyme on the alkaline side.

The titer of the protease is not particularly limited as long as the uncooked rice can be reduced in protein. However, considering the cost and the texture after cooking, the titer of the protease is preferably 25,000 units or less per 25 g of rice. Here, the enzyme titer 1
The unit refers to casein as a substrate at 45 ° C. for 10 minutes (pH 8.0 for the alkaline enzyme, pH 5.10 for the acidic enzyme).
The amount of the enzyme that releases 1 μg of tyrosine per minute in the reaction 5).

The temperature at the time of the enzyme treatment is defined in the above range for the following reason. When the treatment temperature is lower than 45 ° C., the reactivity of the enzyme is reduced, the treatment time for reducing the protein of uncooked rice is prolonged, and the propagation of various bacteria cannot be prevented. On the other hand, when the treatment temperature exceeds 70 ° C., the stability of the enzyme is lowered, and it becomes impossible to sufficiently reduce the protein content of uncooked rice. A more preferred processing temperature is 45 to 60 ° C.

The enzymatic treatment of the uncooked rice may be carried out while the rice is kept stationary in a proteolytic enzyme solution. Is preferred in view of When such circulation or air bubbling is employed, it is preferable to perform the treatment slowly so that the rice is not broken.

For example, when rice is reduced in protein with a proteolytic enzyme solution while circulating the enzyme solution, an enzyme reaction tank capable of storing the enzyme solution and a predetermined amount of uncooked rice are accommodated in the reaction tank. A rice case that is housed and supported so that it can be taken out of the tank, and a liquid supply means that supplies an enzyme solution to a level in which the rice case supported in the tank is submerged in the reaction tank; Enzyme solution circulating means for circulating the enzyme solution in the tank with a weak water flow such that the rice housing rice does not move, and an enzyme solution outlet for discharging the enzyme solution in the reaction tank after the enzyme reaction of the rice housing rice, Washing water supply means for supplying washing water so that rice stored in the rice case does not move in the reaction tank after discharging the enzyme solution; and washing water connected to the lower part of the reaction tank to wash rice stored in the rice case. Wall overflows from the submerged rice box level Down type rice low protein reduction apparatus and a overflow pipe is used.

In the first step of the enzyme treatment, the pH of the enzyme-treated rice is allowed to be adjusted after washing with water. This pH adjustment is performed in order to whiten the rice after the enzyme treatment and to return the rice treated with the alkaline enzyme solution to the acidic side to enhance the preservability. An acid solution is used for pH adjustment. This acid solution is not particularly limited as long as it can be used for food, and for example, a citric acid solution, an acetic acid solution, a lactic acid solution and the like can be used.

(Second step) The low-protein, uncooked rice obtained in the first step is dried to reduce the water content to 25%.
４０40% by weight.

The moisture content of the uncooked rice which has been reduced in protein by drying is specified for the following reason. If the moisture content of the rice is less than 25% by weight, cracking cannot be prevented. On the other hand, if the water content of the rice exceeds 40% by weight, the rice will be in a state of porridge by the subsequent heat treatment.
More preferably, the moisture content of the low-protein uncooked rice is 34 to 38% by weight.

(Third Step) The uncooked rice dried in the second step is heated so that the cooking value (C value) becomes 6 (minutes) or more.

The heat treatment is preferably carried out in a state where uncooked rice is sealed in a suitable packaging material (eg, a retort pouch) through which moisture does not pass. In the heat treatment, if the C value is less than 6 (minutes), the resulting low protein rice will have uneven whiteness and impair the original appearance of rice. A more preferred C value is 9 (minutes) or more.

According to the present invention described above, the protein in the rice can be easily subjected to an enzymatic degradation reaction by enzymatically treating uncooked rice at a temperature of 45 to 70 ° C. in the presence of a heat-resistant protease. Therefore, the protein can be easily and quickly reduced (the protein content can be reduced to 以下 or less of that before the treatment) in a short time.

Further, by carrying out the enzyme reaction at a relatively high temperature of 45 to 70 ° C., propagation of various bacteria can be prevented.
Furthermore, the low protein content of uncooked rice is reduced to a water content of 25%.
By performing the drying treatment so as to be ４０40% by weight, cracking due to impact or the like can be prevented.

Further, by performing a heat treatment so that the C value becomes 6 (minutes) or more after the drying, low protein rice having a transparent color close to the original appearance of rice can be obtained.

Furthermore, even when rice is cooked under the same conditions as ordinary rice, it is possible to eat low-protein cooked rice having a good texture. In addition, low-protein cooked rice with a good texture can be enjoyed even when cooked in a microwave oven.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings. (Example 1) Fig. 1 is an explanatory view showing the overall structure of a low-protein apparatus used for producing low-protein rice of Example 1, and Fig. 2 is an enzyme reaction tank used in the low-protein apparatus of Fig. 1. FIG. 3 is a cross-sectional side view of the enzyme reaction tank used in the protein reduction device of FIG. In the figure, reference numeral 1 denotes an enzyme reaction tank capable of storing an enzyme solution P, and 2 denotes a plurality of upper and lower (for example, three upper and lower) rices which accommodate and support a predetermined amount of uncooked rice A in the enzyme reaction tank 1. The rice case 2 in each stage is formed in a tray or basket shape having a number of small holes (not shown) through which rice grains do not fall. Have.

The rice case 2 of each stage is housed and supported in the enzyme reaction tank 1 by being inserted from the front wall opening of the enzyme reaction tank 1 along the rails 3 on both sides of the tank under the guide of wheels 4. Then, the opening / closing lid 5 for closing the opening of the front wall of the reaction tank 1 so as not to leak the liquid is opened as shown in FIG. 3 after discharging the enzyme solution P in the tank so that it can be taken out of the tank. Equipped.

At the upper part of the reaction tank 1, there is provided an empty room 7 partitioned by a shower generating panel 6 having a large number of water spray holes, through which the enzyme solution P or the washing water W is supplied. 1 is supplied as shower water having little water hammer action.

A drain discharge pipe 8 having a valve d1 and an enzyme solution outlet 9 for discharging the enzyme solution P in the reaction tank 1 after the enzymatic reaction of the uncooked rice A are provided below the reaction tank 1. An electric heater 11 for heating and holding the enzyme solution P in the tank is provided in a lower liquid chamber 10 defined by a bottom of the tank where the drain discharge pipe 8 and the enzyme solution outlet 9 are opened and the lowermost rice case 2a. And a rotary blade 12 (rotated by a motor (not shown)) for gently stirring the enzyme solution P on the bottom side in the tank.

The enzyme solution circulating means 13 circulates the enzyme solution P in the reaction tank 1 with a weak water flow such that the uncooked rice A does not move. The lower liquid chamber 10 and the upper empty chamber 7 of the reaction tank 1 are circulated. To the circulation pipe line 14 with the valve V1 connecting
The circulation pump 15 for circulating the enzyme solution P in the tank from below to above is incorporated.

The liquid supply means 20 supplies the enzyme solution P to the level L where the rice case 2 supported in the tank is submerged in the reaction tank 1 as shown in FIG. A tank 21, an enzyme solution recovery tank 22 for recovering the enzyme solution P discharged from the enzyme solution outlet 9 of the reaction tank 1,
The enzyme solution recovery tank 22 and the enzyme solution tank 21
And a mixing tank 23 for mixing the enzyme solution P supplied from the above and supplying the mixed solution to the enzyme reaction tank 1.

The enzyme solution tank 21 has a drain discharge pipe 24 provided with a valve d3, a lid opening / closing port 25 for introducing enzyme powder and a pH adjuster into the tank, and water W 'or buffer solution in the tank 21. And a water supply pipe 26 provided with a valve V5 for supplying the enzyme solution P formed in the tank 21.
Is sucked up by the operation of the suction pump 27 and is supplied to the mixing tank 23 through the enzyme solution supply pipe 28 provided with the valve V4.

In the enzyme solution tank 21, an electric heater 11a for heating and holding the enzyme solution P, and a rotary blade 12a (rotated and driven by a motor (not shown)) for gently stirring the enzyme solution P are provided. Is provided.

The enzyme solution recovery tank 22 includes a valve d.
2, a vent hole 30 formed in the upper wall of the tank, and an electric heater 11 b for heating and holding the enzyme solution in the tank, and the enzyme solution P collected in the tank 22. Is sucked up by the operation of the suction pump 31, and the mixture tank 2 is supplied through the enzyme solution supply pipe 32 with the valve V3.
3 to be sent.

The connection pipe 16 provided with a valve V2 for connecting the enzyme solution discharge port 9 of the enzyme reaction tank 1 and the enzyme solution recovery tank 22 is provided with the enzyme solution P in the enzyme reaction tank 1 in the recovery tank 22. The pump 17 for collection which feeds to is provided. The mixing tank 23 is provided with a rotating blade 12b for mixing an enzyme solution, which is driven to rotate by a motor (not shown). When such a rotary blade 12b is provided in the mixing tank 23, the enzyme solution tank 21 and the enzyme solution recovery tank 22
Can be quickly mixed and supplied to the enzyme reaction tank 1 from the connection pipe line 18 provided with the valve V6.

The water supply line 37 is connected to the lower liquid chamber 10 of the reaction tank 1 and discharges and recovers the enzyme solution P from the tank.
Is supplied to the position of the rice immersion level L with a weak water flow that does not float. The washing water supply pipe 33 supplies the washing water W from the upper portion into the reaction tank 1 after the washing preliminary water is supplied to the position where the washing reserve water reaches the rice case submerging level L in the reaction tank 1. The washing water supply line 33 and the water supply line 37 constitute washing water supply means.
The cleaning water supply pipe 33 and the water supply pipe 37 are provided with valves V7 and V9, respectively. When the cleaning water W is supplied to the upper chamber 7 of the reaction tank 1 by opening the valve V7 of the passage 33, the water stored in the tank (preliminary cleaning water) is supplied from the water spray hole of the shower generation panel 6 as shower water having little water hammer action. Water is sprayed on the liquid surface. Therefore, the rice after the enzyme reaction does not lose its shape during washing.

The siphon overflow pipe 34 is
The washing water W is connected to the lower liquid chamber 10 of the reaction tank 1 and overflows the washing water W from the position of the rice case immersion level L when washing the rice A accommodated in the rice case. The overflow pipe 34 is also provided with a valve V8. I have.

Next, a method for reducing the protein content of uncooked rice (Kirara) using the aforementioned protein reduction device will be described. First, three upper and lower rice casings 2 each containing 1000 g of uncooked rice (Kirara) A were stored and supported in the enzyme reaction tank 1 as shown in FIG. Then, 4
000 ml of a 0.05 M acetate buffer (pH 4.0) and Peptidase R (trade name, manufactured by Amano Pharmaceutical Co., Ltd.) were added so that the total activity was 40,000 units.
A was turned to prepare an enzyme solution P.

Next, the valves V4 and V6 are opened and the suction pump 27 is operated to supply the enzyme solution P in the enzyme solution tank 21 into the enzyme reaction tank 1. At this time, the enzyme solution P is supplied into the reaction tank 1 from the water spray hole of the shower generation panel 6 as shower water having little water hammer action. Subsequently, when the enzyme solution P was accumulated in the enzyme reaction tank 1 to a level L at which the rice casing 2 was submerged (the overflow position by the overflow pipe 34), the suction pump 27 was stopped, and the valves V4 and V6 were closed. By rotating the impeller 12 of the enzyme reaction tank 1, the valve V1
Is opened, and the circulation pump 15 is operated, so that the lower chamber
While slowly stirring the enzyme solution P of
Was circulated in a weak water flow such that uncooked rice A did not move, and an enzyme reaction was performed for 12 hours. At this time, the enzyme solution P in the tank was heated and maintained at 45 ° C. by the electric heater 11.

After the completion of the enzymatic reaction, the valve V1 is closed and the circulation pump 15 is stopped. Subsequently, the valve V2 is opened, the recovery pump 17 is operated, the enzyme solution P in the enzyme reaction tank 1 is transferred to the enzyme solution recovery tank 22, and the valve V2 is closed when the reaction tank 1 is empty. The collection pump 17 was stopped.

Next, after discharging and recovering the enzyme solution P from the tank, the valve V9 of the water supply pipe 37 was opened to supply the preparatory washing water Wa to a position where the rice casing submerged level L was reached. When the washing preliminary water Wa is supplied to the position of the submerged rice case L in the reaction tank 1, the valve V9 is closed, and the washing water supply line 3 is closed.
The valve V7 of No. 3 and the valve V8 of the overflow pipe 34 were opened, and the washing water W was discharged from the overflow pipe 34 while supplying the washing water W into the reaction tank 1, thereby washing the low-protein rice for 2 hours. After the washing of the rice housed in the rice box is completed, the valve V7 of the washing water supply pipe 33 and the valve V8 of the overflow pipe 34 are closed, the valve d1 of the drain discharge pipe 8 is opened, and the residual washing water W in the reaction tank 1 is opened. Was completely discharged.

Next, the washed rice was immersed in 2000 ml of a 0.5% citric acid aqueous solution for 1 hour, washed again with running water for 1 hour, and air-dried so that the water content of the rice became 35%. Subsequently, the air-dried rice was placed in a retort pouch, sealed, and heated at a temperature of 90 ° C. and a pressure of 1 atm for 20 minutes. In addition, the C value by this heat treatment was 11 (minutes). By this step, about 1200 g of low protein rice was obtained.

The results of analysis (in terms of dry matter) of the obtained low protein rice are shown in Table 1 below. Table 1 also shows the results of component analysis (in terms of dry matter) of rice (Kirara) before the protein reduction treatment.

[0046]

[Table 1]

Reference Example 1 First, a 0.5 M glycine-sodium hydroxide buffer (p
(H9.0) Protease S (trade name, manufactured by Amano Pharmaceutical Co., Ltd.) was dissolved in 2000 ml to obtain a total activity of 1,000,000 units to prepare an enzyme solution. Subsequently, rice (Kirara) 100 containing the enzyme solution in a tank and further washing rice
After containing 0 g and immersing at room temperature for 2 hours, the enzyme solution was treated for 24 hours while stirring it by air bubbling while maintaining the enzyme solution at 60 ° C. The rice after the enzyme treatment was washed with running water for 2 hours. Next, the washed rice was immersed in 2000 ml of 0.05% acetate buffer (pH 4.0) for 1 hour, washed again with running water for 1 hour, and air-dried so that the water content of the rice became 37%. . After that, put the air-dried rice in a retort pouch and seal it.
The heat treatment was performed while maintaining the temperature at 0 ° C. and the pressure of 1 atm for 10 minutes. In addition, the C value by this heat treatment was 24 (minutes). By this step, 1220 g of low protein rice was obtained.

The results of analysis of the obtained low protein rice (in terms of dry matter) are shown in Table 2 below. Table 2 also shows the results of component analysis (in terms of dry matter) of rice (Kirara) before the protein reduction treatment.

[0049]

[Table 2]

(Comparative Example 1) In Comparative Example 1, protein reduction was carried out using a protease which lacks heat resistance, such as actinase (trade name, manufactured by Kaken Pharmaceutical Co., Ltd.) used in a method for producing low allergen rice. This is an example of trying.

First, an actinase (trade name, manufactured by Kaken Pharmaceutical Co., Ltd.) was dissolved in 2000 ml of 0.5 M glycine-sodium hydroxide buffer (pH 9.0) so that the total activity became 1 million units to prepare an enzyme solution. did. Subsequently, 1000 g of washed rice (Kirara) is immersed in this enzyme solution at room temperature for 2 hours, and then the enzyme solution is kept at 37 ° C and 60 ° C for 24 hours while stirring the enzyme solution by air bubbling. Processed. Each rice after the enzyme treatment was washed with running water for 2 hours. Then, each of the washed rice was added to a 0.05% acetate buffer (pH 4.0) 20
It was immersed in 00 ml for 1 hour, washed again with running water for 1 hour, and air-dried so that the water content of the rice became 35%. Through this process, about 1200 g of enzyme-treated rice was obtained.

The obtained enzyme-treated rice (37 ° C. and 60 ° C.)
Table 3 shows the results of the analysis (in terms of dry matter).
Table 3 also shows the results of component analysis (in terms of dry matter) of rice (Kirara) before the enzyme treatment.

[0053]

[Table 3]

As is apparent from Tables 1 to 3, uncooked rice is used in a solution containing a heat-resistant protease as in Example 1 and Reference Example 1 at a temperature of 45 to 70 ° C. in a range (60 ° C.). By subjecting the rice to the enzyme treatment, low protein rice having a protein content reduced to half or less of the rice before the enzyme treatment can be obtained.

On the other hand, in Comparative Example 1 in which actinase lacking heat resistance was used as the protease, the protein content was reduced to half or less of the rice before the enzyme treatment when the enzyme solution was kept at 37 ° C. Low protein rice cannot be obtained. In Comparative Example 1, when the enzyme solution was maintained at 60 ° C., the enzyme was placed under severe conditions. For this reason, the ability to degrade proteins is reduced, and the effect of reducing protein is further reduced as compared with the case of treatment at 37 ° C.

(Evaluation of Low Protein Rice) After washing 150 g of the commercially available killara used in Example 1, 200 cc of water was added thereto and immersed for 1 hour.
5; Zojirushi Mahobin Co., Ltd.). This is a reference example. In addition, the cooking time was about 17 minutes and the steaming time was about 10 minutes.

100 g of low protein rice obtained in Example 1
And 90 cc of water were put in an electronic rice cooker (NZF-T05; trade name, manufactured by Zojirushi Mahobin Co., Ltd.), lightly stirred, and immediately turned on. Cooking time was about 12 minutes and steaming time was about 10 minutes.

100 g of low protein rice obtained in Reference Example 1
And 80 cc of water in a microwave (Toshiba Corporation product name;
ER-1020JF (W)) and cooked for 7 minutes at 600 W output.

Reference Examples thus obtained, Example 1 and Reference Example 1
The cooked rice was subjected to a sensory test for appearance, aroma, taste, stickiness and hardness by six panelists. The results are shown in Tables 4 to 8 below.

The appearance, aroma, taste, stickiness and hardness were evaluated on the following five levels. 1) Appearance evaluation 5; Very good 4; Glossy, white and uniform in grain 3; White and plump 2; Color is dull and cracked 1; Bad 2) Aroma 5; Very good 4; Good smell peculiar to cooked rice 3; Generally good 2; Slightly unpleasant odor 1; Poor 3) Taste 5; Very good 4; Feel umami and sweet 3; Generally good 2; Tasteless 1; Poor 4) Sticky 5; Good 4; moderate toughness and good 3; slightly sticky 2; sticky 1: bad 5) hardness 5; very good 4; chewy and good 3; generally good 2; hard 1; bad

[0061]

[Table 4]

[0062]

[Table 5]

[0063]

[Table 6]

[0064]

[Table 7]

[0065]

[Table 8]

As apparent from Tables 4 to 8, the low protein rice of Example 1 and Reference Example 1 had the same appearance, aroma, taste, stickiness and hardness as the rice before the low protein treatment (Reference Example). It turns out that it has.

[0067]

As described in detail above, according to the present invention, uncooked rice can be reduced in protein by a simple processing step,
It has a transparent color similar to uncooked rice and has the property of not breaking easily, and it can cook rice in the same manner as ordinary rice or in a microwave oven without washing rice, and has a good texture. A method for producing low-protein rice useful for kidney disease patients who can eat rice can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of a protein reduction device used for protein reduction according to a first embodiment of the present invention.

FIG. 2 is a central longitudinal sectional view of an enzyme reaction tank used in the protein reduction device of FIG.

FIG. 3 is a cross-sectional side view of an enzyme reaction tank used in the protein reduction device of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Enzyme reaction tank, P ... Enzyme solution, 2 ... Rice case, A ... Uncooked rice, 6 ... Shower generation panel, 8 ... Drain discharge pipe, 9 ...
Enzyme solution outlet, 11 (11a, 11b) ... electric heater,
12 (12a, 12b): Rotating blades, 13: Enzyme solution circulation means, 14: Circulation piping, 15: Circulation pump, 20: Enzyme solution supply means, 21: Enzyme solution tank, Enzyme solution recovery tank, 23 ... Mixing tank, 27, 31: Enzyme solution suction pump, W: Wash water, Wa: Wash preliminary water, 33: Wash water supply line, 34: Overflow pipe.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Koji Nakajima, Inventor Koji Nakajima 2-13-40 Konan, Minato-ku, Tokyo Inside Toyo Suisan Co., Ltd. (56) References JP-A-6-303925 (JP, A) JP-A Heisei 2-265447 (JP, A) JP-A-2-167040 (JP, A) JP-A-8-38077 (JP, A) JP-A-9-65840 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A23L 1/10 A23L 1/105

Claims (2)

(57) [Claims] Claims 1. Uncooked rice has an optimal pH on the acidic side.
The presence of that heat-resistant proteolytic enzymes, 45 to 70 ° C.
Enzymatic treatment at low temperature to reduce protein; drying low-protein non-cooked rice to a water content of 25 to 40% by weight; cooking value of the dried non-cooked rice (C value) is 6
(Min) a step of performing a heat treatment so as to be at least as long as described above. Wherein said enzymatic treatment according to claim 1, wherein said either by slowly circulating the solution containing non-cooked rice and the proteolytic enzyme, or is agitated performing air bubbling in a bath Method for producing low protein rice.