HK1236339B - Vinegar-containing cooked rice having sustained/retained sour taste - Google Patents

Description

Rice containing edible vinegar with a lasting and retaining effect of sourness

Technical Field

The present invention relates to rice containing edible vinegar having a lasting and maintaining effect of sourness (so-called good sourness retention) and a method for preparing the same, as well as a method for lasting and maintaining the sourness of rice containing edible vinegar and seasoning vinegar having a lasting and maintaining effect of sourness of rice containing edible vinegar.

Background Art

Recently, a diet pattern called "home-meal replacement" is emerging in which people buy food cooked outside the home (pre-cooked food) at supermarkets or convenience stores and eat it at home.

The cooked food consumed by this "home meal replacement" (e.g., boxed lunches, sushi, side dishes, etc.) usually takes more than several hours from the time the food manufacturer prepares it to the time the consumer consumes it.

Therefore, for example, in the case of rice containing edible vinegar such as sushi rice used for sushi, the pleasant sour taste of the sushi rice will weaken as time passes after the vinegar is added to the rice, and there is a problem that the flavor of freshly made sushi rice can no longer be felt.

This is a phenomenon called vinegar scattering that occurs over time in sushi rice. It is believed that this is caused by the thinning of the rice due to the vinegar saturating the rice from the surface to the inside, or by changes in the texture of the sushi rice due to changes in the starch structure, which affects the taste.

As a technique for preventing the reduction in sourness of sushi rice during storage, for example, a technique has been proposed in which ethyl 3-methylthiopropionate is added to rice vinegar at a concentration range of 0.006 to 0.2 ppb (see Patent Document 1).

This technology can significantly improve the reduction in sourness of sushi rice over time (making the sourness less noticeable), but it is limited to rice vinegar. Therefore, a new technology that can significantly improve the reduction in sourness of sushi rice over time (making the sourness less noticeable) and is not limited to rice vinegar is sought.

Prior art literature

Patent Literature

Patent document 1: WO2009/066514.

Summary of the Invention

Problems to be solved by the invention

(1) The object of the present invention is to provide: rice containing edible vinegar having a lasting and maintaining effect of sourness and a method for preparing the same; a method for lasting and maintaining the sourness in rice containing edible vinegar; and seasoned vinegar having a lasting and maintaining effect of sourness in rice containing edible vinegar.

(2) The object of the present invention is to provide: rice containing edible vinegar, in which the vinegar used is not limited to rice vinegar, and a method for preparing the same.

Means for solving problems

The present inventors have conducted intensive research to solve the above-mentioned conventional problems.

As a result, they discovered that vinegar-containing rice with a sustained, retaining sour taste can be obtained by incorporating a cold-water-soluble starch degradation product into vinegar-containing rice at a ratio of 0.05 to 1% by mass of the acid concentration in the vinegar-containing rice. Based on this knowledge, they completed the present invention.

That is, the present invention relates to the following contents.

(1) A rice containing edible vinegar, characterized in that the rice contains a cold water-soluble starch degradation product in a ratio of 0.05 to 1 part by mass per 1 part by mass of acid contained in the rice containing edible vinegar.

(2) The rice containing edible vinegar according to (1) above, wherein the rice used for the rice containing edible vinegar is non-glutinous rice.

(3) The rice containing edible vinegar according to (1) or (2), wherein the rice containing edible vinegar is sushi rice.

(4) The rice containing edible vinegar according to any one of (1) to (3) above, wherein the cold water-soluble starch degradation product is a cold water-soluble starch degradation product obtained by treating starch to reduce its molecular weight by acid or enzyme, or a cold water-soluble starch degradation product obtained by treating chemically treated processed starch to reduce its molecular weight by acid, oxidant, or enzyme.

(5) The rice containing edible vinegar according to any one of (1) to (4), wherein the cold water-soluble starch degradation product is a cold water-soluble starch degradation product mainly containing at least amylopectin.

(6) The vinegar-containing rice according to (4) above, wherein the cold-water-soluble starch degradation product is a cold-water-soluble starch degradation product of waxy corn starch or glutinous rice.

(7) The vinegar-containing rice according to any one of (1) to (6), wherein the cold water-soluble starch degradation product is a starch degradation product having a DE value of 2 to 9.

(8) The rice containing edible vinegar according to any one of (1) to (7), wherein the cold water-soluble starch degradation product is contained after cooking.

(9) A method for preparing rice containing edible vinegar having a sustained and retaining effect of sourness, characterized in that the rice containing edible vinegar contains a cold water-soluble starch degradation product at a ratio of 0.05 to 1 part by mass per 1 part by mass of acid contained in the rice containing edible vinegar.

(10) A method for maintaining the sour taste of rice containing edible vinegar, characterized in that the rice containing edible vinegar contains a cold water-soluble starch degradation product at a ratio of 0.05 to 1 part by mass per 1 part by mass of acid contained in the rice containing edible vinegar.

(11) A flavored vinegar having a function of lasting and maintaining the sour taste in rice containing edible vinegar, the flavored vinegar comprising edible vinegar and a cold water-soluble starch decomposition product.

(12) A seasoning vinegar having a function of maintaining or preserving the sour taste of rice containing edible vinegar, the seasoning vinegar comprising the following ingredients: edible vinegar; a cold water-soluble starch decomposition product; one or more seasonings selected from the group consisting of sugars, high-intensity sweeteners, salt, organic acids, amino acids, nucleic acids, organic acid salts, soy sauce, broth, and honey; and water.

Effects of the Invention

According to the present invention, there can be provided rice containing edible vinegar having a lasting and retaining effect of sourness and a method for preparing the same.

Furthermore, according to the present invention, a method for sustaining and maintaining the sour taste in rice containing vinegar can be provided.

Furthermore, according to the present invention, it is possible to provide a flavored vinegar having a function of lasting and retaining the sour taste in rice containing vinegar.

DETAILED DESCRIPTION

Hereinafter, the present invention will be described in detail.

The present invention relates to the following.

The first aspect of the present invention is a rice containing edible vinegar, characterized in that the rice contains a cold-water-soluble starch degradation product at a ratio of 0.05 to 1 part by mass per 1 part by mass of acid contained in the rice containing edible vinegar.

In the present invention, the rice containing edible vinegar may be any rice containing edible vinegar, and its type and the like are not particularly limited.

The rice is cooked, and the type of rice used is not limited, and it can be either polished rice or glutinous rice. However, as described later, sushi rice is preferred as the rice containing edible vinegar, and therefore polished rice is more preferably used.

Examples of edible vinegar include grain vinegars such as rice vinegar, rice black vinegar, barley black vinegar, and glutinous rice vinegar; fruit vinegars such as apple vinegar and grape vinegar; and brewed vinegars, as well as synthetic vinegars. Among these, brewed vinegars, particularly grain vinegar, are preferred.

As the edible vinegar, one having an acetic acid concentration in a generally used range of about 4.0 to 20.0 mass/volume can be used.

As described above, the vinegar used in the first vinegar-containing rice of the present invention is not limited to rice vinegar.

The vinegar-containing rice in the present invention may be rice made with "vinegar" of course, or may be rice made with so-called "flavored vinegar" obtained by flavoring the vinegar with sugar, salt, or the like.

Preferred examples of the vinegar-containing rice of the present invention include sushi rice using the above-mentioned seasoning vinegar (particularly sushi vinegar).

The cold-water-soluble starch degradation product contained in the rice containing edible vinegar of the present invention refers to a cold-water-soluble starch degradation product obtained by treating starch to reduce its molecular weight by acid, alkali, or enzyme, or a cold-water-soluble starch degradation product obtained by treating etherified or esterified processed starch to reduce its molecular weight by acid, oxidizing agent, or enzyme. More preferably, it is a cold-water-soluble starch degradation product obtained by decomposing starch by acid or enzyme.

Here, the starch is not particularly limited, and various starches such as corn starch, potato starch, rice starch, and wheat starch can be used.

The processed starch may be any of etherified starch, esterified starch, oxidized starch, and the like, and examples thereof include hydroxypropylated starch, hydroxypropylated phosphate cross-linked starch, and acetylated phosphate cross-linked starch.

Next, examples of the acid include oxalic acid and hydrochloric acid.

Examples of the enzyme include α-amylase and β-amylase.

The cold water-soluble starch degradation product is preferably a cold water-soluble starch degradation product mainly containing at least amylopectin, and particularly preferably a cold water-soluble starch degradation product containing substantially 100% amylopectin and containing almost no amylose.

The “cold water-soluble starch degradation product mainly containing at least amylopectin” refers to a cold water-soluble starch degradation product containing about 70% or more of amylopectin.

Here, examples of starches that serve as raw materials for the starch degradation products include starches that contain almost no amylose and are substantially 100% amylopectin, such as waxy corn starch and glutinous rice, and starches that contain a small amount (up to about 30%) of amylose but are not 100% amylopectin, such as potato, wheat, corn, and cassava.

Specifically, the cold-water-soluble starch degradation product containing substantially 100% amylopectin and containing almost no amylose is preferably a cold-water-soluble starch degradation product of waxy corn starch or glutinous rice, that is, a cold-water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch, glutinous rice, or the like. In particular, a cold-water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch is preferred.

The cold water-soluble starch degradation product preferably has a DE (Dextrose Equivalent) value of 2 to 9, and particularly preferably has a DE value of 2 to 5.

Here, the DE value is an index showing the degree of hydrolysis of starch, and is a value expressed as a percentage of the solid content, with the amount of reducing sugars being represented as the amount of glucose, as shown in the following formula (I).

・DE=[Direct reducing sugar (in the form of glucose)/solid content]×100…Formula (I)

Specifically, the following are preferred examples of such cold-water-soluble starch degradation products. All of these are cold-water-soluble starch degradation products that contain virtually no amylose and are substantially 100% amylopectin, and are composed of 100% waxy corn starch. Furthermore, all of these have a DE range of 2 to 9.

First, specific examples of "cold water-soluble starch degradation products" obtained by decomposing starch with acid or enzymes include PDX #100 (manufactured by Matsutani Chemical Industry Co., Ltd., DE = 2 to 5; a cold water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch), PDX #1 (manufactured by Matsutani Chemical Industry Co., Ltd., DE = 7 to 9; a cold water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch), and Sandex #30 (manufactured by Sanwa Starch Industry Co., Ltd., DE = 2 to 5; a cold water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch).

Next, examples of "cold water-soluble starch degradation products" obtained by treating etherified or esterified processed starch with an acid, an oxidizing agent, or an enzyme to reduce the molecular weight include, for example, Emarusuta 900 (manufactured by Matsutani Chemical Industry Co., Ltd.; a degradation product of hydroxypropylated phosphate-crosslinked starch made from waxy corn).

Among them, PDX #100 and Sandex #30 are particularly preferred because they are cold-water-soluble starch degradation products obtained by treating starch with acid or enzymes to reduce its molecular weight, are substantially 100% amylopectin and contain almost no amylose, are composed of 100% waxy corn starch, and have a DE value in the range of 2 to 5.

Regarding the method of adding the cold water-soluble starch degradation product to rice containing edible vinegar, the cold water-soluble starch degradation product may be added during cooking or after cooking.

However, when the rice is added during cooking, the sour taste is well maintained (sour taste is sustained and retained), but the rice tends to burn slightly during cooking, so it is more preferable to add the rice after cooking.

It should be noted that the cold-water-soluble starch degradation product can be contained in the rice containing edible vinegar separately from the edible vinegar to be contained in the rice, or can be contained in the rice containing edible vinegar in the form of a flavored vinegar containing the cold-water-soluble starch degradation product. Furthermore, the rice containing vinegar can be contained in the form of a flavored vinegar containing a cold-water-soluble starch degradation product, a seasoning such as sugar, and the like, and the edible vinegar.

The first vinegar-containing rice of the present invention is characterized by containing the above-mentioned cold water-soluble starch degradation product in an amount of 0.05 to 1.00 parts by mass, preferably 0.1 to 1.0 parts by mass, more preferably 0.15 to 0.7 parts by mass, and even more preferably 0.4 to 0.7 parts by mass per 1 part by mass of the acid contained in the vinegar-containing rice.

If the content of the cold-water-soluble starch degradation product is too low, the intensity of the sour taste will decrease (due to poor retention of the sour taste) after the rice containing vinegar is stored for 48 hours from immediately after cooking, which is not preferable.

On the other hand, if the content of the cold-water-soluble starch degradation product is too high, the sour taste is well maintained, but the fullness of the rice grains is lost, which is not preferable.

Here, the "acid" in "per 1 part by mass of the acid contained in the rice containing vinegar" basically refers to acetic acid, which is the main component of vinegar. However, in the case where the rice containing vinegar contains organic acids other than acetic acid (for example, citric acid, malic acid, gluconic acid, etc.), the concept includes these.

The acid concentration in rice containing vinegar (especially sushi rice) is not particularly limited as long as it is within a commonly used concentration range, but is generally about 0.2 to 0.4 mass/mass %.

The content of cold-water-soluble starch degradation products in cooked rice (especially sushi rice) is not particularly limited, but is 0.013 to 0.26 mass/mass %, preferably 0.026 to 0.26 mass/mass %, more preferably 0.04 to 0.2 mass %, and even more preferably 0.1 to 0.2 mass %.

Thus, the first vinegar-containing rice of the present invention is a vinegar-containing rice containing 0.05 to 1 part by mass of a cold-water-soluble starch degradation product per 1 part by mass of the acid contained in the vinegar-containing rice, thereby providing a vinegar-containing rice having a sustained and retaining effect of sourness.

Here, "having a sustained and retaining effect of sourness" means that, with respect to the rice containing edible vinegar of the present invention 1, the intensity of the sourness immediately after cooking is sustained and retained even after 48 hours of storage after vinegar containing at least edible vinegar and a cold-water-soluble starch degradation product (particularly sushi vinegar containing a cold-water-soluble starch degradation product) is sprinkled on the rice immediately after cooking. In other words, even after making the rice containing edible vinegar such as sushi rice, the intensity of the sourness immediately after cooking is sustained and retained even after 48 hours.

The first aspect of the present invention is as described above.

A second aspect of the present invention relates to a method for producing vinegar-containing rice having a sustained and retaining effect of sourness, characterized in that the vinegar-containing rice contains a cold-water-soluble starch degradation product at a ratio of 0.05 to 1 part by mass per 1 part by mass of acid contained in the vinegar-containing rice.

Therefore, basically, the description of the first aspect of the present invention is also made in the same manner in the second aspect of the present invention.

That is, the terms such as "rice", "rice containing vinegar", "vinegar", and "cold water-soluble starch degradation product" are the same as those described in the first aspect of the present invention.

Next, in the second production method of the present invention, the method of adding the cold water-soluble starch degradation product to the rice containing edible vinegar can be carried out in the same manner as described in the first method of the present invention. The cold water-soluble starch degradation product can be added during or after cooking.

Moreover, when it is added during cooking, the sour taste is well maintained (the sour taste is sustained and retained), but since the rice tends to be slightly burnt during cooking, it is more preferable to add it after cooking. This is also the same as described in the first aspect of the present invention.

In the second production method of the present invention, the cold water-soluble starch degradation product is contained in a ratio of 0.05 to 1.00 parts by mass, preferably 0.1 to 1.0 parts by mass, more preferably 0.15 to 0.7 parts by mass, and even more preferably 0.4 to 0.7 parts by mass per 1 part by mass of the acid contained in the rice containing edible vinegar.

Here, if the content of the cold water-soluble starch degradation product is too low, the intensity of the sour taste decreases (the sour taste is not maintained well) after the rice containing vinegar is stored for 48 hours from the time of cooking, which is not preferable.

On the other hand, if the content of the cold-water-soluble starch degradation product is too high, the sour taste is well maintained, but the fullness of the rice grains is lost, which is not preferable.

In the second production method of the present invention, the rice containing edible vinegar contains a cold-water-soluble starch degradation product at a specific ratio of 0.05 to 1 part by mass per 1 part by mass of the acid contained in the rice containing edible vinegar. Apart from this, the production method is not particularly limited and can basically be any conventional method for producing rice containing edible vinegar.

For example, a method for making rice containing vinegar contain a cold-water-soluble starch decomposition product after cooking is used as an example. The method involves washing rice such as polished round-grained rice and then soaking it in water for cooking. The cold-water-soluble starch decomposition product and the vinegar to be contained in the cooked rice can be added separately to the cooked rice, thereby making the rice containing vinegar contain the starch decomposition product. Alternatively, the vinegar can be contained in the rice by adding the starch decomposition product in the form of a flavored vinegar containing the cold-water-soluble starch decomposition product. Alternatively, the vinegar can be contained in the rice by adding the starch decomposition product in the form of a flavored vinegar composed of vinegar, a seasoning such as sugar, and the like.

It should be noted that, in the case of preparing sushi rice, for example, rice containing edible vinegar can generally be prepared by subjecting cooked rice to conventional methods, including the steps of steaming, mixing with vinegar, loosening, and cooling. Therefore, when the rice containing edible vinegar is added after cooking, it is sufficient that the rice containing edible vinegar contains a specific ratio of 0.05 to 1 part by mass of a cold-water-soluble starch degradation product per 1 part by mass of the acid contained in the rice containing edible vinegar when the vinegar is added.

Thus, the vinegar-containing rice produced by the second production method of the present invention is rice having a sustained and retaining effect of sour taste.

Furthermore, a third aspect of the present invention relates to a method for maintaining the sour taste of rice containing vinegar, characterized in that the rice containing vinegar contains a cold-water-soluble starch degradation product at a specific ratio of 0.05 to 1 part by mass per 1 part by mass of acid contained in the rice containing vinegar.

That is, similarly to the above, by adding a cold-water-soluble starch degradation product to the rice containing vinegar at a ratio of 0.05 to 1.00 parts by mass, preferably 0.1 to 1.0 parts by mass, more preferably 0.15 to 0.7 parts by mass, and even more preferably 0.4 to 0.7 parts by mass per 1 part by mass of the acid contained in the rice containing vinegar, as shown in the third aspect of the present invention, the sour taste of the rice containing vinegar can be sustained and maintained.

Next, a fourth aspect of the present invention relates to a flavored vinegar having the effect of sustaining and retaining the sour taste in rice containing edible vinegar, wherein the rice containing edible vinegar comprises edible vinegar and a cold-water-soluble starch decomposition product, and wherein when added to the rice containing edible vinegar, the flavored vinegar acts as an agent for sustaining and retaining the sour taste of the rice containing edible vinegar.

Here, "flavored vinegar" generally refers to edible vinegar flavored with sugar, salt, etc.

The fourth aspect of the present invention is a flavored vinegar containing edible vinegar and a cold-water-soluble starch decomposition product. The flavored vinegar may contain various seasonings in addition to edible vinegar and a cold-water-soluble starch decomposition product.

Specific examples of the seasoning include sugars, high-intensity sweeteners, salt, organic acids, amino acids, nucleic acids, organic acid salts, soy sauce, broth, and honey.

Among them, it is preferred to use one or more seasonings selected from the following: sugars, high-sweetness sweeteners, salt, organic acids, amino acids, nucleic acids, organic acid salts, soy sauce, soup and honey as seasonings, and providing seasoned vinegar using the seasonings is the fifth aspect of the present invention.

That is, the fifth aspect of the present invention relates to a flavored vinegar having the effect of sustaining and retaining the sour taste in rice containing edible vinegar, wherein the rice containing edible vinegar comprises: edible vinegar; a cold-water-soluble starch degradation product; one or more seasonings selected from sugars, high-intensity sweeteners, salt, organic acids, amino acids, nucleic acids, organic acid salts, soy sauce, broth, and honey; and water. As in the fourth aspect of the present invention, when added to rice containing edible vinegar, the flavored vinegar acts as an agent for sustaining and retaining the sour taste of the rice containing edible vinegar.

In the fourth and fifth aspects of the present invention, the terms "edible vinegar" and "cold water-soluble starch degradation product" are the same as those described in the first aspect of the present invention.

In addition, in the fifth aspect of the present invention, examples of the "sugars" include granulated sugar, fructose-glucose solution, glucose, starch syrup, and reduced starch syrup.

Next, examples of “organic acids” include citric acid, malic acid, gluconic acid, and acetic acid.

Furthermore, examples of the "amino acid" include sodium glutamate, glycine, and alanine.

Furthermore, examples of the "nucleic acid" include sodium inosinic acid and sodium guanylic acid.

Examples of the "broth" used as the seasoning include kelp broth, bonito (loofed fish) broth, and shiitake mushroom broth.

Examples of the "organic acid salt" include sodium succinate and sodium citrate.

Examples of the “high-intensity sweetener” include sucralose, stevia, acesulfame, saccharin and saccharin sodium, aspartame, thaumatin, licorice extract, and neotame.

The flavored vinegar described in the fourth and fifth aspects of the present invention is preferably used in such a manner that the vinegar-containing rice contains 0.05 to 1.00 parts by mass, preferably 0.1 to 1.0 parts by mass, more preferably 0.15 to 0.7 parts by mass, and even more preferably 0.4 to 0.7 parts by mass of a cold-water-soluble starch degradation product per 1 part by mass of the acid contained in the vinegar-containing rice.

According to the seasoned vinegars described in the fourth and fifth aspects of the present invention, it is possible to achieve a sustained and retaining effect of the sour taste in rice containing edible vinegar.

It should be noted that, in the present invention, if starch is used instead of the cold water-soluble starch degradation product, the starch will not be uniformly contained in the rice containing edible vinegar, and a stable effect cannot be obtained.

Example

Hereinafter, the present invention will be described with reference to Examples and the like, but the present invention is not limited to these Examples in any way.

Test Examples 1 to 4 and Comparative Test Example 1 (Verification of the Sustainability and Retention of Acidity Using Sushi Vinegar Containing Cold-Water-Soluble Starch Decomposition Products)

(1) Preparation of sushi vinegar and sushi rice

The raw materials of the formulation shown in Table 1 were uniformly mixed to produce various sushi vinegars.

Each type of sushi vinegar was sprinkled onto freshly cooked rice to make sushi rice.

In addition, "Starch degradation products 1 to 4" in Table 1 are as follows.

Starch degradation product 1: Cold water-soluble starch degradation product (PDX #100; manufactured by Matsutani Chemical Industry Co., Ltd., DE = 2-5, a cold water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch)

Starch degradation product 2: Cold water-soluble starch degradation product (Sandex #30; manufactured by Sanwa Starch Industry Co., Ltd., DE = 2-5; a cold water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch)

Starch degradation product 3: Cold water-soluble starch degradation product (Emarusuta 900 (Matsuya Chemical Industry Co., Ltd.); a low-molecular-weight product of hydroxypropylated phosphate-crosslinked starch made from waxy corn)

Starch degradation product 4: PDX #1; manufactured by Matsutani Chemical Industry Co., Ltd., DE = 7-9, a cold-water-soluble starch degradation product obtained by reducing the molecular weight of waxy corn starch.

(2) Sensory evaluation

An experienced research team conducted sensory evaluations of the intensity of the sourness of the prepared sushi rice, examining the persistence and retention of the sourness, at the exact moment (hereinafter, sometimes referred to as "immediately after cooking") the rice was sprinkled with sushi vinegar; 24 hours after (hereinafter, sometimes referred to as "24 hours after cooking") the rice was sprinkled with sushi vinegar; and 48 hours after (hereinafter, sometimes referred to as "48 hours after cooking") the rice was sprinkled with sushi vinegar.

The sourness intensity of sushi rice was evaluated based on the following criteria: the sourness intensity of the sushi rice was rated "5" at the moment when the sushi vinegar was sprinkled on the rice immediately after cooking (i.e., "immediately after cooking"), with the sourness intensity being the highest. The sourness intensity was then evaluated relative to the following criteria, starting from the same "5" and progressing through five levels of sourness, namely "4," "3," "2," and "1," as the sourness gradually weakened.

Furthermore, sensory evaluation was performed including the effects on the texture of sushi rice.

Furthermore, a comprehensive evaluation was conducted based on the following three-stage criteria.

These results are shown in Table 1.

・Sourness intensity

5: Just like after cooking, you can feel the full sour taste.

4: The sour taste is slightly weaker than that of freshly cooked rice.

3: The sour taste is slightly weaker than that of freshly cooked rice.

2: The sour taste is much weaker than that of freshly cooked rice.

1: The sour taste is significantly reduced compared to freshly cooked rice.

・Comprehensive evaluation

A: Good

B: Average~Good

C: Poor

Table 1

As shown in Table 1, according to Test Examples 1 to 4 (Examples of the present invention), the use of sushi vinegar containing a cold-water-soluble starch degradation product allows the sourness intensity immediately after cooking to be sustained and maintained even 48 hours after making rice containing edible vinegar, such as sushi rice, and no adverse effect on the texture of the sushi rice is observed.

On the other hand, according to Comparative Test Example 1 (Comparative Example), when sushi vinegar containing no cold-water-soluble starch degradation products is used, the intensity of the sour taste immediately after cooking rice, such as sushi rice, is no longer perceptible 48 hours after the rice containing edible vinegar is prepared.

Test Examples A to H (Verification of the Effective Amount of Cold Water-Soluble Starch Decomposition Products)

Sushi rice was prepared and evaluated in the same manner as in Test Examples 1 to 4 and Comparative Test Example 1, except that the ingredients of the formulations shown in Tables 2 and 3 were used (ie, the content of the cold-water-soluble starch degradation product was changed).

The results are shown in Tables 2 and 3.

Table 2

Table 3

As shown in Tables 2 and 3, when the content of the cold-water-soluble starch degradation product is within the range of 0.05 to 1.00 parts by mass per 1 part by mass of the acid in the sushi rice, the sourness intensity immediately after cooking is maintained even 48 hours after making rice containing edible vinegar, such as sushi rice, and no adverse effect on the texture of the sushi rice is observed.

In contrast, it was found that if the content of the cold-water-soluble starch degradation product is outside the range of 0.05 to 1.00 parts by mass per 1 part by mass of the acid in the sushi rice, the intensity of the sour taste immediately after cooking is not sustained or maintained until 48 hours after making rice containing edible vinegar, such as sushi rice. Or, even if the intensity of the sour taste immediately after cooking is sustained or maintained, the fullness of the rice grains is lost.

Test Examples X and Y (Confirmation of the Effect of Acid Concentration on Sushi Rice)

Sushi rice was prepared and evaluated in the same manner as in Test Examples 1 to 4 and Comparative Test Example 1, except that the raw materials of the formulation shown in Table 4 were used (ie, the acid concentration of the sushi rice was changed).

The results are shown in Table 4.

Table 4

As shown in Table 4, even when the acid concentration of the sushi rice was changed, the intensity of the sour taste immediately after cooking was maintained until 48 hours after the production of rice containing edible vinegar, such as sushi rice, and no adverse effect on the texture of the sushi rice was observed.

Test Example 5 (Verification of the effect of maintaining the sour taste according to the addition time of the cold water-soluble starch degradation product)

Sushi rice was prepared and evaluated in the same manner as in Test Examples 1 to 4 and Comparative Test Example 1, except that a cold-water-soluble starch degradation product was added to the water used for cooking the rice.

The results are shown in Table 5 together with the results of Test Example 1 and Comparative Test Example 1 in which a cold water-soluble starch degradation product was sprinkled on cooked rice immediately after cooking.

Table 5

As shown in Table 5, even when a cold-water-soluble starch degradation product is added to the water used for cooking and the rice is cooked, the intensity of the sour taste immediately after cooking is maintained until 48 hours after making rice containing edible vinegar, such as sushi rice. However, the rice tends to be slightly burnt during cooking.

Industrial Applicability

According to the present invention, there are provided rice containing edible vinegar having a lasting and maintaining effect of sourness and a method for preparing the same; a method for lasting and maintaining the sourness in rice containing edible vinegar; and seasoned vinegar having a lasting and maintaining effect of sourness in rice containing edible vinegar.

Therefore, the present invention is expected to be effectively used in the food industry targeting supermarkets, convenience stores, etc. because it can make the taste of cooked food, especially sushi rice, consumed in so-called "home meal replacements" close to that of freshly made sushi rice.

Claims (33)

1. Rice containing edible vinegar, characterized in that: relative to each part by mass of acid contained in the aforementioned rice containing edible vinegar, it contains, at a ratio of 0.05 to 1 part by mass, cold water-soluble starch decomposition product during or after cooking, wherein the cold water-soluble starch decomposition product is a cold water-soluble starch decomposition product that has been treated to reduce the molecular weight of starch by acid, alkali or enzyme, and has a DE value of 2 to 9, and the acid contained in the aforementioned rice containing edible vinegar is an organic acid containing acetic acid, and the concentration of acid contained in the aforementioned rice containing edible vinegar is 0.2 to 0.4 mass/mass. 2. The rice containing edible vinegar according to claim 1, wherein, relative to each part by weight of acid, it contains cold water-soluble starch decomposition products in a ratio of 0.15 to 0.7 parts by weight. 3. The rice containing edible vinegar as described in claim 1 or 2, wherein the aforementioned rice containing edible vinegar is made from salt, and contains cold water-soluble starch decomposition products in a ratio of 0.013 to 0.259 parts by mass relative to 1 part by mass of salt. 4. The rice containing edible vinegar as described in claim 1 or 2, wherein the acid concentration in the aforementioned rice containing edible vinegar is 0.2~0.4% by mass, and the content of cold water soluble starch decomposition products is 0.013~0.26% by mass. 5. The rice containing edible vinegar as described in claim 3, wherein the acid concentration in the aforementioned rice containing edible vinegar is 0.2~0.4% by mass, and the content of cold water soluble starch decomposition products is 0.013~0.26% by mass. 6. The rice containing edible vinegar as described in claim 1 or 2, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 7. The rice containing edible vinegar as described in claim 1 or 2, wherein the rice used in the aforementioned rice containing edible vinegar is japonica rice. 8. The rice containing edible vinegar as described in claim 1 or 2, wherein the aforementioned rice containing edible vinegar is sushi rice. 9. The rice containing edible vinegar as described in claim 1 or 2, wherein the aforementioned cold water-soluble starch decomposition product is a cold water-soluble starch decomposition product that at least mainly contains amylopectin. 10. The rice containing edible vinegar as described in claim 1 or 2, wherein the aforementioned water-soluble starch decomposition product is waxy corn starch or water-soluble starch decomposition product of glutinous rice. 11. A method for preparing rice containing edible vinegar that has a sustained and lasting sour taste, characterized in that: for the rice containing edible vinegar, relative to each part by mass of acid contained in the aforementioned rice containing edible vinegar, a cold water-soluble starch decomposition product is contained at a ratio of 0.05 to 1 part by mass during or after cooking, wherein the cold water-soluble starch decomposition product is a cold water-soluble starch decomposition product that has been treated to reduce the molecular weight of starch by acid, alkali or enzyme, and has a DE value of 2 to 9, and the acid contained in the aforementioned rice containing edible vinegar is an organic acid containing acetic acid, and the concentration of acid contained in the aforementioned rice containing edible vinegar is 0.2 to 0.4 mass/mass. 12. The method for preparing rice containing edible vinegar with a sustained and maintained sour taste according to claim 11, wherein, relative to each part by weight of acid, it contains cold water-soluble starch decomposition products in a ratio of 0.15 to 0.7 parts by weight. 13. The method for preparing rice containing edible vinegar with a sustained and maintaining sour taste as described in claim 11 or 12, wherein, for rice containing edible vinegar, the content of cold water-soluble starch decomposition products is such that it contains salt at a concentration of 0.013 to 0.259 parts by weight relative to 1 part by weight of salt. 14. The method for preparing rice containing edible vinegar with a sustained and maintained sour taste as described in claim 11 or 12, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 15. A method for maintaining and preserving the sour taste in rice containing edible vinegar, characterized in that: for rice containing edible vinegar, relative to each part by mass of acid contained in the aforementioned rice containing edible vinegar, a cold water-soluble starch decomposition product is contained at a ratio of 0.05 to 1 part by mass during or after cooking, wherein the cold water-soluble starch decomposition product is a cold water-soluble starch decomposition product that has been treated to reduce the molecular weight of starch by acid, alkali or enzyme, and has a DE value of 2 to 9, and the acid contained in the aforementioned rice containing edible vinegar is an organic acid containing acetic acid, and the concentration of the acid contained in the aforementioned rice containing edible vinegar is 0.2 to 0.4 mass/mass. 16. The method for maintaining and preserving the sour taste in rice containing edible vinegar as described in claim 15, wherein, relative to each part by weight of acid, it contains cold water-soluble starch decomposition products in a ratio of 0.15 to 0.7 parts by weight. 17. The method for maintaining or retaining the sour taste in rice containing edible vinegar as described in claim 15 or 16, wherein, for rice containing edible vinegar, the content of cold water-soluble starch decomposition products is such that it contains salt at a concentration of 0.013 to 0.259 parts by weight relative to 1 part by weight of salt. 18. The method for maintaining or preserving the sour taste in rice containing edible vinegar as described in claim 15 or 16, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 19. A seasoning vinegar, which is a seasoning vinegar for rice containing edible vinegar that has a sustained and maintained sour taste, the seasoning vinegar containing edible vinegar and cold water-soluble starch decomposition product, wherein the cold water-soluble starch decomposition product is contained in a ratio of 0.05 to 1 part by mass relative to 1 part by mass of acid, and the cold water-soluble starch decomposition product is a cold water-soluble starch decomposition product that has been treated to reduce the molecular weight of starch by acid, alkali or enzyme, and has a DE value of 2 to 9, and the acid contained in the aforementioned rice containing edible vinegar is an organic acid containing acetic acid, and the concentration of the acid contained in the aforementioned rice containing edible vinegar is 0.2 to 0.4 mass/mass. 20. The seasoning vinegar of claim 19, which has a sustained and maintaining effect of acidity, wherein the seasoning vinegar further contains salt. 21. The seasoning vinegar with a sustained and maintained sour taste as described in claim 19, wherein the edible vinegar contained in the aforementioned seasoning vinegar is 400-600 kg relative to 1000 kg of seasoning vinegar. 22. The seasoning vinegar with a sustained and maintained sour taste as described in claim 20, wherein the edible vinegar contained in the aforementioned seasoning vinegar is 400-600 kg relative to 1000 kg of seasoning vinegar. 23. The seasoning vinegar with a sustained and maintained acidity as described in claim 19, wherein the acidity of the aforementioned seasoning vinegar is 1.98 to 2.64 by mass. 24. The seasoning vinegar with a sustained and maintained acidity as described in claim 20, wherein the acidity of the seasoning vinegar is 1.98 to 2.64 by mass. 25. The flavored vinegar with a sustained and maintaining acidity as described in any one of claims 19, 21 and 23, wherein it contains the aforementioned cold water-soluble starch decomposition product in a ratio of 0.11 to 2.20% by mass. 26. The flavored vinegar with a sustained and maintaining acidity as described in any one of claims 20, 22 and 24, wherein it contains the aforementioned cold water-soluble starch decomposition product in a ratio of 0.11 to 2.20% by mass. 27. The flavored vinegar with a sustained and maintaining acidity as described in any one of claims 20, 22 and 24, wherein the aforementioned salt is contained in a ratio of 8.730 to 9.65% by mass. 28. The flavored vinegar of claim 26, which has a sustained and maintaining effect of acidity, wherein the aforementioned salt is contained in a ratio of 8.730 to 9.65% by mass. 29. The flavored vinegar with a sustained and maintaining acidity according to any one of claims 19, 21 and 23, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 30. The flavored vinegar with a sustained and maintaining acidity according to any one of claims 20, 22 and 24, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 31. The flavored vinegar with a sustained and maintained sour taste as described in claim 26, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 32. The flavored vinegar with a sustained and maintained sour taste as described in claim 28, wherein the aforementioned water-soluble starch decomposition product is a starch decomposition product with a DE value of 2 to 5. 33. A seasoning vinegar, which is a seasoning vinegar for rice containing edible vinegar that has a sustained and maintained sour taste, comprising the following components: edible vinegar; cold water-soluble starch decomposition products; one or more seasonings selected from sugars, high-sweetness sweeteners, salt, organic acids, amino acids, nucleic acids, organic acid salts, soy sauce, broth, and honey; and water. The rice contains, relative to each part by mass of acid, 0.05 to 1 part by mass of the cold water-soluble starch decomposition product, wherein the cold water-soluble starch decomposition product is a cold water-soluble starch decomposition product that has been treated with acid, alkali or enzyme to reduce the molecular weight, and has a DE value of 2 to 9. The acid contained in the rice containing edible vinegar is an organic acid containing acetic acid, and the acid concentration contained in the rice containing edible vinegar is 0.2 to 0.4 mass/mass.