JP5496609B2 - Method for producing aseptically packaged cooked rice - Google Patents

Description

  The present invention relates to a method for suppressing acidity and / or acid odor in food, a food using the same, and an agent used therefor. The present invention is useful for suppressing acidity and / or acid odor in sterile cooked rice with adjusted pH.

  Rice foods in airtight containers that can be stored at room temperature and can be eaten simply by warming are commercially available. In such foods, sterilization or growth inhibition of Clostridium botulinum is essential, and the main methods for this are the so-called retort treatment or similar treatment methods, the US Department of Health and Human Services, Food and Drug Administration (Food and There is a method of adjusting the conditions specified for Acidified Foods of Drug Administration (FDA), that is, pH to 4.6 or less.

Patent Document 1 describes (1) the process of washing the polished rice, (2) the process of removing from the immersion water after being immersed in immersion water, (3) the process of steaming with a steamer, (4) in a gas barrier heat-resistant container in aseptic equipment filled with oxygen scavenger, in the fully method for producing cooked rice steaming comprises the step of sealing, in a process of the above step in and above (2) (3), the rice gluconodeltalactone, gluconic acid Or by contacting with an aqueous solution containing at least one selected from a salt thereof or a mixture thereof as an essential component, and adjusting the pH of the cooked rice to 4.0 to 4.8, Disclosed is a method for producing cooked rice. According to this method, it is stated that it is possible to prevent the growth of causative bacteria such as Clostridium botulinum.

  Patent Document 2 is a process for producing a cooked rice food by putting a set amount of food containing at least rice that has been drained after being immersed in water into a container that is sequentially transported and cooking with cooked water added to the container. Disclosed is a method for producing cooked rice food, wherein an enzyme preparation containing at least lysozyme is added to the cooked water, and the opening of the container is sealed after the completion of cooking. In this method, it is stated that a gluconic acid solution can be added to the cooking water, and the combined use of gluconic acid and lysozyme can suppress the amount of each used.

Japanese Patent Publication No.7-89880 Japanese Patent Laid-Open No. 2001-346529 (Patent No. 4211963)

  The inventors of the present invention have studied about adjusting the pH of a sterile room temperature cooked rice food so that the pH is 4.6 or less. However, when acid is added in an effective amount for adjusting pH in cooked rice foods, the acid-derived sourness and acid odor may be at a level that cannot be ignored, particularly when heated. It goes without saying that it is more desirable as a product if the acidity and acid odor peculiar to acids can be reduced to an acceptable level for cooked rice.

Thus, as a result of various studies of substances having an effect of reducing acidity and acid odor, the present inventors have found that certain oligosaccharides have a remarkable effect on acid, and have completed the present invention.
The present invention provides the following:
[1] A method for producing cooked rice foods:
(1) Raw materials including:
Rice;
Gluconodelta lactone, gluconic acid, citric acid, adipic acid, succinic acid, acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphoric acid, phytic acid, itaconic acid, α-ketoglutaric acid, their salts or Selected from the group consisting of hydrates and mixtures of any of these, an amount of 1 part by weight or less with respect to 100 parts by weight of the resulting cooked rice food, and an amount effective to make the pH lowering agent pH 4.6 or less PH lowering agent;
0.5 to 10 parts by weight of oligosaccharide mixture with respect to 1 part by weight of the pH-lowering agent, wherein the oligosaccharide mixture contains 5 to 7 sugars in total of 15% by weight or more, preferably further 2 to 3 sugars in total Containing 10% by weight or more; and preparing water, and
(2) A method for producing cooked rice food, comprising a step of obtaining a cooked rice food by heating and cooking a mixture of raw materials under conditions effective for sterilization and cooking.
[2] (1) including a step of cooking after filling raw materials in a container having an opening; and (2) sealing the opening of the container with a pre-sterilized sealing material after cooking [1] The manufacturing method as described.
[3] In [1] or [2], the pH-lowering agent is selected from the group consisting of glucono delta lactone, gluconic acid, citric acid, salts or hydrates thereof, and any mixture thereof. The manufacturing method as described.
[4] Any of [1] to [3], wherein the oligosaccharide mixture is 2 to 6 parts by weight with respect to 1 part by weight of the pH-lowering agent, and contains 5 to 7 sugars in total of 30% by weight or more. 1. The production method according to 1.
[5] The oligosaccharide mixture is 2 to 6 parts by weight with respect to 1 part by weight of the pH-lowering agent, and contains 5 to 7 sugars in total of 15% by weight or more, and further 3 sugars in an amount of 20% by weight or more. [1] The production method according to any one of [3].
[6] 1 part by weight or less of a pH lowering agent for 100 parts by weight of cooked rice food (in this case, the pH lowering agent includes gluconic acid and / or glucono delta lactone); and
0.5 to 10 parts by weight of oligosaccharide mixture with respect to 1 part by weight of the pH-lowering agent (in this case, the oligosaccharide mixture contains 5 to 7 sugars in an amount of 15% by weight or more, preferably 2 to 3 sugars in an amount of 10% by weight or more. )
Including
Cooked rice food with a pH of 4.6 or less.
[7] Glucono delta lactone, gluconic acid, citric acid, adipic acid, succinic acid containing oligosaccharide mixture containing 15-7% by weight of 5-7 sugars, preferably 10% by weight of 2-3 sugars , Acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphoric acid, phytic acid, itaconic acid, alpha-ketoglutaric acid, salts or hydrates thereof, or any mixture thereof, and / or Or an acid odor suppressor.
[8] Gluconodelta lactone, gluconic acid, citric acid, adipic acid, succinic acid, using an oligosaccharide mixture containing 15 to 5% by weight of 5-7 sugars, preferably 10% by weight or more of 2 to 3 sugars, Selected from the group consisting of acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphoric acid, phytic acid, itaconic acid, α-ketoglutaric acid, salts or hydrates thereof, or any mixture thereof Any acidity and / or acid odor control method.

<Raw materials>
pH lowering agent:
As used herein, “pH reducing agent” means glucono delta lactone, gluconic acid, citric acid, adipic acid, succinic acid, acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, unless otherwise specified. , Phosphoric acid, phytic acid, itaconic acid, α-ketoglutaric acid, salts or hydrates thereof, and any mixture thereof. In the present invention, the pH lowering agent is used to lower the pH of the cooked rice food and improve the storage stability.

  The preferred pH-lowering agent used in the present invention is preferably one that does not strongly exhibit acidity and acid odor when used in an appropriate amount in cooked rice foods. Also, by adding an oligosaccharide mixture described later, acidity and acid odor are added. Those that can be masked are preferred. Examples of such pH lowering agents are glucono delta lactone, gluconic acid, citric acid.

  Gluconodelta lactone (D-glucono-1,5-lactone, sometimes referred to as GDL or gluconolactone) is in equilibrium with gluconic acid in aqueous solution. As food additives, it is used as a coagulant such as tofu and cheese, a swelling agent such as biscuits and bread, a pH adjuster such as ham and sausage, and a sour agent such as juice. Gluconic acid ((2R, 3S, 4R, 5R) -2,3,4,5,6-pentahydroxyhexanoic acid) is a component present in trace amounts in natural products (honey, fruits, rice). Citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid; sometimes 3-hydroxypentanedioic acid-3-carboxylic acid) is a natural product and is relatively contained in citrus fruits. It is an ingredient.

  The amount of the pH lowering agent in the present invention is an amount that is effective for setting the pH of the cooked rice food as a final product to 4.6 or less, and that does not give an unmaskable acidity / acid odor to the cooked rice food. It is. A person skilled in the art can appropriately design the amount used depending on the type of the pH-lowering agent to be used. In many cases, the pH-lowering agent is used in an amount of 1 part by weight or less.

For example, when GDL is used as a pH-lowering agent, 0.05 parts by weight of cooked rice food, 0.05
-1 part by weight, preferably 0.1-0.75 part by weight, more preferably 0.2-0.5 part by weight.

  In this invention, the quantity of a pH reducing agent can also be shown as a ratio added to the water (cooking water) added when cooking immersion rice (what made water absorb the rice). For example, when GDL is used as the pH lowering agent, the amount of the pH lowering agent in the cooking water is 0.05 to 2% by weight, preferably 0.1 to 2% by weight, and more preferably 0.2 to 1% by weight.

  In the present invention, the pH of the cooked rice food as the final product is adjusted to 4.6 or less by adding a pH lowering agent. If it is 4.6 or less, there is no particular limitation, but it is preferably pH 4.5 or less. In the present invention, when referring to the pH value for cooked rice food, it means a value measured by the method described in the examples of the present specification, unless otherwise indicated.

In the present invention, the pH-lowering agent does not depend on the production method, and any of synthetic products, natural products, and products produced by fermentation can be used.
Oligosaccharide mixture:
In the present invention, the term “oligosaccharide mixture” refers to a mixture of carbohydrates mainly composed of oligosaccharides (2-20 monosaccharides having glycosidic bonds), and saccharides other than oligosaccharides (monosaccharides, 21 sugars). The above may be included. Examples of carbohydrates that are the main components of the oligosaccharide mixture are malto-oligosaccharides (glucose with α-1,4 glucoside bonds. For example, maltose (may be referred to as G2), maltotriose (G3), malto Tetraose (G4), maltopentaose (G5), maltohexaose (G6), maltoheptaose (G7)), branched oligosaccharide (containing α-1,6 glucoside bond structure of glucose. For example, isomaltose , Panose), gentiooligosaccharide (containing a β-1,6 glucoside bond structure of glucose. For example, gentiobiose, gentianose), nigerooligosaccharide (for example, nigerose, nigerosyl glucose, nigerosyl maltose), trehalose. In the present specification, glucose or glucose unit may be expressed as G, fructose or fructose unit as F, and maltose as M.

In the present invention, the oligosaccharide mixture is used to suppress the acidity and / or acid odor exhibited by the pH lowering agent.
The oligosaccharide mixture of the present invention contains 5 to 7 sugars, a total of 15% by weight or more. In addition, when showing the composition of an oligosaccharide mixture in this invention, it has shown as a ratio in the saccharide | sugar (solid content) in the oligosaccharide mixture except the case where it describes especially. For example, when “total 5 to 7 sugars is 15% by weight”, the total amount of sugars contained in the oligosaccharide mixture is 100 parts by weight, and the sugar units contained in the oligosaccharide mixture are 5 to 7 This means that the total amount of carbohydrates is 15% by weight. Such a ratio can be measured using conventional techniques such as high-speed chromatography.

  The oligosaccharide mixture of the present invention contains a high ratio of 5 to 7 sugars having a high acid odor suppressing effect. In a preferred embodiment, since the oligosaccharide mixture has a particularly high effect of suppressing acid odor by G6 and G7, 5 to 7 sugars, preferably G6 and / or G7, is 10% by weight or more, more preferably 20% by weight. % Or more, more preferably 30% by weight or more.

  The oligosaccharide of the present invention also preferably contains 5 to 7 sugars in a high ratio and contains 2 to 3 sugars having a high acidity suppressing effect in a high ratio. In a preferred embodiment, the oligosaccharide mixture contains 5 to 7 sugars (preferably G6 and / or G7) in total of 7.5% by weight or more, more preferably 10% by weight or more, and further preferably 15% by weight or more, and 2 ˜3 sugars (preferably disaccharides and trisaccharides or trisaccharides) are contained in an amount of 10% by weight or more, more preferably 15% by weight or more, and further preferably 20% by weight or more.

In the present invention, the amount of the oligosaccharide mixture can be 0.1 to 10 parts by weight with respect to 1 part by weight of the pH lowering agent. Preferably it is 1-8 weight part, More preferably, it is 2-6 weight part.
In this invention, the quantity of an oligosaccharide mixture can also be shown as a ratio added to cooking water. The amount (solid content) of the oligosaccharide mixture in the cooking water is 0.1 to 10% by weight, preferably 0.5 to 7.5% by weight, and more preferably 1 to 6% by weight.

In the present invention, various oligosaccharide mixtures can be used regardless of the production method and origin.
Rice and others:
In the present invention, “rice” means uncooked food unless otherwise specified, and “rice” means brown rice, divided rice, white rice (sometimes referred to as polished rice), and mixtures thereof. including. In the present invention, the rice may be japonica (Japanese type, short grain), indica (Indian, long grain), or Javanica (Java type, large grain), or glutinous or glutinous rice. There is no limitation on the varieties, but varieties having excellent taste can be particularly preferably used. Examples of this good variety are Koshihikari, Hitomebore, Hinohikari, Akitakomachi, Kinuhikari, Kirara, Haenuki, Hoshino Yume, and Tsugaru Romantic.

As the “water” of the raw material in the present invention, those usually used in cooked rice production can be used.
In the present invention, as raw materials, in addition to those described above, cereals other than rice (eg, wheat, whey, fin, acne), ingredients (eg, beans, vegetables, fruits, livestock meat, fish and shellfish), seasonings, foods The additive (for example, lysozyme) accept | permitted as can be used suitably.

In the present invention, the term “boiled rice food” includes white rice and cooked rice (rice cooked by cooking ingredients mixed with rice and various ingredients).
<Manufacturing method>
In the present invention, the cooked rice food is produced by a method including the steps of preparing raw materials and cooking the mixture of raw materials under conditions that are sterilizing effective and cooking effective.

  The production method of the present invention preferably includes a step of heating and cooking after filling a raw material in a container having an opening; and then sealing the opening of the container with a pre-sterilized sealing material after the cooking. The cooked rice food produced by such a process can be kept at room temperature and kept in a sterilized state for a sufficiently long time (for example, over 6 months), and can be immediately heated in a microwave oven or the like.

  In the first step of the present invention, necessary raw materials are prepared. The rice can be washed, soaked and drained by conventional methods. When using ingredients, it is pretreated as necessary. All or a part of the raw materials are mixed and filled in a predetermined amount in a separate container having an apparatus for cooking rice or an opening.

  In the subsequent sterilization and cooking process, if the individual containers are filled, sterilization may be performed separately. In this sterilization process, cooking water is not added to the raw material contained in the container, and it is heated at a high temperature for a predetermined short time. The heating method in this case is a predetermined number of times (for example, about 6 to 8 times in total) intermittently in a short time of about 4 to 8 seconds, for example, in a chamber maintained at a high temperature of 140 to 145 ° C. This should be done in and out. This sterilization step may be performed under high pressure (for example, about 1.2 to 4 atmospheres).

In the cooking process, all raw materials including water are cooked under conditions effective for cooking (for example, heating with steam of about 100 to 105 ° C. for several tens of minutes).
In the case of a form filled in individual containers, a sealing process can be performed following the cooking process. Here, the sterilized sealant is heat-sealed to the container opening of the cooked container food by a conventional method to completely seal the container opening. The container-containing cooked product that has been subjected to the sealing step may be further subjected to a steaming step (eg, several tens of minutes at 90 ° C. to 100 ° C.), and then may be subjected to cooling using water or the like as necessary. If necessary, after that, various inspections (for example, pinhole inspection and weight inspection) can be further performed to obtain a final product.

<Effects of the present invention>
INDUSTRIAL APPLICABILITY According to the present invention, a cooked rice food having a pH of 4.6 or less, aseptic, and having reduced acidity and acid odor of additives used for pH reduction and a method for producing the same are provided.

  According to the study by the present inventors, 2 to 3 sugars have an inhibitory effect on the acidity of the pH lowering agent, but do not suppress the acid odor so much. Also, G4 seems to be less effective for both, while G6 and / or G7 are highly effective in suppressing the acidity / acid odor of the pH additive. In addition, the oligosaccharide mixture is effective not only for GDL but also for citric acid, and can also be effective for the acidity and acid odor of other pH lowering agents.

  According to the study by the present inventors, compared to G6 and G7, maltose, fructose-glucose sugar solution, and sucrose, which are superior in sweetness of sugar itself, did not have a high effect on sourness and acid odor. Further, considering that the acid added as a pH lowering agent to the cooked rice food is a small amount compared to the acid amount in foods having acidity such as beverages and sushi rice, the sourness and acid odor of the oligosaccharide mixture in the present invention is as follows. It is presumed that the suppression mechanism is different from the mechanism of action when masking acidity with sugar sweetness in the prior art. Therefore, it can be said that this invention provides the use different from the acidity suppression of a prior art.

  The present invention also includes glucono delta lactone, gluconic acid, citric acid, adipic acid, which contains an oligosaccharide mixture containing 5-7 sugars at 15% by weight or more, preferably 2-3 sugars at 10% by weight or more. Acidity of succinic acid, acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphoric acid, phytic acid, itaconic acid, α-ketoglutaric acid, salts or hydrates thereof, or any mixture thereof And / or an acid odor inhibitor (in the present invention, the term “agent” refers to a composition in a form suitable as a food additive and does not include existing foods); 15% by weight or more, preferably using an oligosaccharide mixture containing 2 to 3 sugars by 10% by weight or more, glucono delta lactone, gluconic acid, citric acid, adipic acid, succinic acid, acetic acid, glacial acetic acid, tartaric acid, Lactic acid, fumaric acid, apple A method for suppressing acidity and / or acid odor selected from the group consisting of phosphoric acid, phytic acid, itaconic acid, α-ketoglutaric acid, salts or hydrates thereof, or any mixture thereof provide.

[Example 1: Study on composition and addition amount of oligosaccharide mixture]
<Method>
In the experiment, the oligosaccharide mixture shown in the table below was used.

Aseptic rice food was produced by the following method.
1) Niigata Koshihikari rice (whiteness 40.5) was lightened by 200g.
2) Washed rice for 30 seconds while mixing gently with running water in a sieve.
3) Move to the ball and rinse 5 times.
4) Four times as much water as raw rice was added to the bowl and soaked at 20 ° C for 1 hour.
5) Add 164ml of the rice cooking water shown in the table below to the soaked rice, and use the rice cooker (MITSUBISHI NJ-JG10), the normal rice cooking conditions set in advance in the rice cooker (sealed heating for about 20 minutes and about 20 minutes) It consists of unsealed heating before and after.) Rice was cooked to obtain cooked rice.

The pH measurement of cooked rice was performed as follows.
1) Nine times of distilled water was added to 5g or more of cooked rice and left at 20 ° C for 30 minutes or more.
2) After confirming that the rice grains were crushed with a finger, homogenized with a stomacher for 3 minutes.
3) The supernatant was collected and measured for pH.

  Sensory evaluation was carried out 30 minutes after cooking. In addition, sensory evaluation was performed by 2 to 3 specialist panelists, using GDL using n = 4 and using citric acid using n = 3. did.

<Result>
The results of pH measurement and sensory evaluation are shown in the table below.

  In the evaluation of acid odor, those with ++++ or more had an acid odor after cooking, which lasted for a while, but +++ did not last. The oligosaccharide mixture or other sugars added had a darker color than the additive-free ones. Although there was almost no difference in the intensity of the color, for example, darker coloring was observed with the addition of cluster dextrin or cyclodextrin than in other cases.

  From (1), it was considered that maltose alone suppressed the acidity a little but did not suppress the acid odor with the amount used. From the comparison of (2) and (3), where good results were obtained, G6 and / or G7 oligosaccharides have the effect of suppressing acidity and acid odor, but G4 seems to be less effective. It was.

From the comparison between (3) and good results (4), in (4), the amount of M (G2) is increased, so there is a possibility of the effect, but G3 is effective. The possibility was suggested.
The difference between (11) and (12) can be considered to be the effect of G7. Given that, G7 is effective alone (even if not mixed with G6).

The oligosaccharide mixture was found to be effective not only for GDL but also for citric acid, but showed particularly good effects on GDL.
From the above, it was considered that GDL acidity suppression and acid odor suppression depend on different substances. A remarkable effect was observed for 2 to 3 sugars for acidity and 6 to 7 sugars for acid odor, but cyclodextrin and cluster dextrin had almost no sour acid odor reducing effect. Compared to G67, maltose, fructose-glucose sugar solution, and sucrose, which are superior to the sweetness of sugar itself, did not have a high effect on sourness and acid odor. It was inferred that the mechanism of action masked by the sweetness of sugar was different.

[Example 2: Confirmation of effect of combination, production of individual food product]
A sterile cooked rice food with a tray was produced by the following method.
1) Niigata Koshihikari (whiteness 43) was immersed in water for 1 hour.
2) 112 g of the soaked rice obtained was filled in a tray.
3) It was sterilized by performing four shots with a heating time of 5 seconds in a pressure heating machine (F value is about 10). After sterilization, 113.5 g of cooking water (150% of fresh rice) was added to the tray and cooked for 32 minutes at around 100 ° C. with a convection steamer.
Cooking water was prepared according to the formulation shown in the table below. The GDL concentration in the cooking water was all 0.4%.
4) After cooking the rice, the tray opening was further sealed with a film and then steamed at 70 ° C or higher for 15 minutes.

  Details of each oligosaccharide mixture used are the same as in Example 1. The oligosaccharide mixture was used in an amount of 30 g as it was without conversion to solid content. For No. 5, G67 and # 360 were mixed in half. G67 has a moisture content of 24 ± 1%, and the solid content of # 360 is 72% or more.

  The sensory evaluation was performed on the cooked product after cooling for 15 minutes with tap water and then heating for 2 minutes with a 500 W microwave oven, after 30 minutes. The results were averaged by n = 3 by 3 expert panelists.

<Result>
The results are shown in the table below.

Acid odor and sourness were suppressed in all prototypes using oligosaccharide mixtures compared to GDL alone.
Furthermore, the prototype was stored at 35 ° C for one month, and the results of sensory evaluation are shown in the table below.

  Acid odor and sourness were suppressed in all prototypes using oligosaccharide mixtures compared to GDL alone. Especially in the prototype used in combination, the acid odor was sufficiently suppressed.

Claims (12)

A method for producing cooked rice food:
(1) Raw materials including:
Rice;
Gluconodelta lactone, gluconic acid, citric acid, adipic acid, succinic acid, acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphoric acid, phytic acid, itaconic acid, α-ketoglutaric acid, their salts or Selected from the group consisting of hydrates and mixtures of any of these, an amount of 1 part by weight or less with respect to 100 parts by weight of the resulting cooked rice food, and an amount effective to make the pH lowering agent pH 4.6 or less PH lowering agent;
0.5 to 10 parts by weight of an oligosaccharide mixture with respect to 1 part by weight of the pH reducing agent, wherein the oligosaccharide mixture contains 5 to 7 sugars in total of 15% by weight or more; And
(2) A method for producing cooked rice food, comprising a step of obtaining a cooked rice food by heating and cooking a mixture of raw materials under conditions effective for sterilization and cooking. 2. The production method according to claim 1, wherein the oligosaccharide mixture further contains 2 to 3 sugars in total of 10% by weight or more. The method according to claim 1 or 2, further comprising: (1) cooking after filling the raw material in a container having an opening; and (2) sealing the opening of the container with a pre-sterilized sealing material after cooking. The manufacturing method as described. The pH-lowering agent according to any one of claims 1 to 3, wherein the pH-lowering agent is selected from the group consisting of glucono delta lactone, gluconic acid, citric acid, salts or hydrates thereof, and any mixture thereof. The manufacturing method as described. The oligosaccharide mixture is 2 to 6 parts by weight with respect to 1 part by weight of the pH-lowering agent, and contains 5 to 7 sugars in total of 30% by weight or more, according to any one of claims 1 to 4. Production method. The oligosaccharide mixture is 2 to 6 parts by weight with respect to 1 part by weight of the pH-lowering agent, and contains 5 to 7 sugars in total of 15% by weight or more, and further 3 sugars in an amount of 20% by weight or more. 5. The production method according to any one of 4 above. 1 part by weight or less of a pH lowering agent for 100 parts by weight of cooked rice food (in this case, the pH lowering agent contains gluconic acid and / or glucono delta lactone); and
0.5 to 10 parts by weight of oligosaccharide mixture with respect to 1 part by weight of the pH lowering agent (in this case, the oligosaccharide mixture contains 5 to 7 sugars by 15% by weight or more)
Including
Cooked rice food with a pH of 4.6 or less. 8. The cooked rice food in a container according to claim 7, wherein the oligosaccharide mixture further contains 2 to 3 sugars in an amount of 10% by weight or more. Containing an oligosaccharide mixture containing at least 15% by weight of 5-7 sugars, glucono delta lactone, gluconic acid, citric acid, adipic acid, succinic acid, acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphorus An acidity and / or acid odor inhibitor for cooked rice to which an acid, phytic acid, itaconic acid, α-ketoglutaric acid, a salt or hydrate thereof, or a mixture of any of these is added . 10. The inhibitor according to claim 9, wherein the oligosaccharide mixture further contains 2 to 3 sugars in an amount of 10% by weight or more. Gluconodelta lactone, gluconic acid, citric acid, adipic acid, succinic acid, acetic acid, glacial acetic acid, tartaric acid, lactic acid, fumaric acid, malic acid, phosphoric acid using an oligosaccharide mixture containing 15% by weight or more of 5-7 sugars , phytic acid, itaconic acid, alpha-ketoglutaric acid, their salts or hydrates, or for rice either it has been added which is selected from the group consisting of any of the mixtures thereof, sour and / or acid smell Suppression method. 12. The method according to claim 11, wherein the oligosaccharide mixture further comprises 10% by weight or more of 2-3 sugars.