JPH1175733A - Frozen cooked rice food that can be thawed without heating - Google Patents

Abstract

(57) [Problem] To provide cooked rice food that can maintain the quality before freezing even after thawing without using a special additive or a thawing device. In addition, to provide cooked rice food that can be eaten without thawing after thawing. SOLUTION: A cooked rice food using cooked rice of polished rice, which can be naturally thawed and eaten at a temperature range of room temperature or higher. The frozen cooked rice food is preferably a frozen form of cooked rice food. The frozen cooked rice food is packaged in a form that tightly accommodates the cooked rice food, such as a package that is packaged under reduced pressure, and more preferably a package that is deep drawn. As the type of cooked rice food at that time, the one to which a seasoning is added has a small change in texture during storage at a low temperature, and the cooked rice food is a food to which a seasoning is added, particularly "sushi". Further, by using additives, it is possible to improve aging resistance, and the cooked rice food contains food additives, preferably salts, most preferably Ca salts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frozen cooked rice that can be thawed without heating so that the cooked rice can be eaten without heating. More specifically, the present invention relates to a frozen cooked rice food that can be thawed without heating and returns to cooked rice food that retains hardness, stickiness, and appearance close to that before freezing even after thawing. In the present invention, "natural thawing at room temperature or higher" means thawing at room temperature, thawing with air at room temperature, natural thawing such as running water thawing, and "heating" means 50 ° C at which starch is gelatinized. This means that the temperature is raised by a microwave oven or a hot water bath while maintaining the above temperature.

[0002]

2. Description of the Related Art Frozen cooked rice has the main advantage of its long-term preservability, but thawing is carried out by heating in a microwave oven or, for pilaf-like products, by direct heat. However, there are also products that do not need to be eaten in a warm state, for example, cooked rice products such as sushi and rice balls. In the case of freezing sushi, in the case of thawing in a microwave oven, it was necessary to devise a method for packaging such as covering with an aluminum vapor-deposited film so as not to be exposed to microwaves. However, sushi usually eats both rice and noodles at room temperature, and some of the noodles are not suitable for microwave heating. Therefore, a sushi that can be thawed without heating is preferred.

[0003] The method of thawing without heating, that is, if the quality of the cooked rice product by natural thawing at room temperature or thawing with running water is maintained so that both the hardness and the stickiness are comparable to those before freezing, especially in products like sushi. Useful. In addition, frozen rice has a hard, sticky texture, including a reduction in the gloss and transparency of the rice, depending on how it is thawed, and a so-called white wax that becomes powdery when severely degraded Sometimes. Rice with such a change is not suitable for eating. In order to prevent quality deterioration due to thawing, there is a method of externally adding additives such as saccharides, but the effect of adding these additives is not sufficient. Although there are cases where a special thawing machine is used (JP-A-57-36969), these are not common.

[0004] Further, for cooked rice foods distributed in the chilled temperature range, it is possible to increase the water content of the rice by increasing the amount of water to control the hardening of the rice.
However, in the case of unheated thawing such as spontaneous thawing of frozen rice, the quality after thawing hardly affects even if the moisture of the rice is changed. Another technique is needed to maintain the quality of cooked rice after thawing.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooked rice food product that can maintain the quality before freezing even after thawing without using a special additive or a thawing device. It is another object of the present invention to provide cooked rice food that can be eaten without being heated after thawing.

[0006]

Means for Solving the Problems The present inventors have studied diligently to achieve the above-mentioned object, and when defrosting and eating frozen rice food without heating, it is possible to package the food under reduced pressure or deep drawing. It was clarified that it was effective, and it was clarified that the type of cooked rice food to which a seasoning was added was suitable. Furthermore, by using additives, it is possible to improve the aging resistance, and among the additives, the effect of adding salts is the highest, and among them, C
It was clarified that the effect of adding salt a was high. The present invention has been completed based on these findings. The present inventors, regarding suppressing the texture change in the low temperature range,
In particular, we have been conducting intensive research on the use of general glutinous rice.
Increasing the amount of water in cooked rice food is the most effective,
A separate application was filed for inventions completed based on that knowledge.

The gist of the present invention is a cooked rice food using cooked rice of polished rice, which is a frozen cooked rice food that can be naturally thawed and eaten at a temperature range of room temperature or higher. The frozen cooked rice food is preferably a frozen form of cooked rice food. The frozen cooked rice food is packaged in a form that tightly accommodates the cooked rice food, such as a package that is packaged under reduced pressure, and more preferably a package that is deep drawn. As the type of cooked rice food at that time, the one to which a seasoning is added has a small change in texture during storage at a low temperature, and the cooked rice food is a food to which a seasoning is added, particularly "sushi". Further, by using additives, it is possible to improve aging resistance, and the cooked rice food contains food additives, preferably salts, most preferably Ca salts.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When thawing frozen cooked rice foods, one of the factors affecting the quality after thawing is the thawing speed. Generally, the freezing speed is considered to be important for the quality of frozen products, but it has been confirmed that the effect on the quality of cooked rice is small unless the freezing speed is extremely low. Therefore, particularly when eating raw rice, it is important to adopt a packaging form in which the thawing speed is controlled, and the higher the thawing speed, the closer the quality after thawing to that before freezing. That is, the time required to pass through the temperature range of -5 to 0 ° C during thawing has the greatest effect on the quality. The shorter the transit time, the closer the quality of the frozen cooked rice will be before freezing.

When thawing at a low temperature such as a refrigerator, the thawing speed becomes extremely slow. Generally, cooked rice is hard, sticky, has no appearance, and has no transparency.
It is difficult to obtain the quality before freezing. However, when thawing at room temperature, the thawing speed increases, and depending on the form of the food, it is possible to obtain almost the same quality as before freezing.

[0010] To control this, it is necessary to increase the thermal conductivity. In addition to reducing the size of the product or reducing the density in the packing method, the rice product must be The problem can be solved by applying a reduced pressure, preferably a reduced pressure, and packaging the product in a deep drawing form so as to adhere to the cooked rice so as not to lose its shape. Boiled rice food products in a molded form are also preferred in that they have a shape adapted to their packaging form. Its main purpose is to reduce the content of air with low thermal conductivity. By this packaging, the thawing time is shortened, and a product of good quality in both appearance and texture can be obtained as compared with aerated packaging and the like.

[0011] The difficulty of maintaining the quality when thawed without heating also differs depending on the type of cooked rice food. Quality is easily maintained in a form to which a seasoning is added, and is represented by, for example, sushi and onigiri. Compared with these forms, it is difficult to maintain the quality of white rice.

In the present invention, the quality can be further improved by adding food additives in addition to devising the above-mentioned packaging form. Examples of the food additive include enzymes, starches, polysaccharides, sugars, sugar alcohols, emulsifiers, and salts. Specifically, the enzyme contains α-amylase, β-amylase, glucoamylase and protease in an amount of 0.01 to 100 U / rice 1
The addition of g is effective, and these are also effective before or after cooking rice.

Suitable starches include waxy corn starch, white ball powder, tapioca starch or modified starch having a high content of amylopectin, and starch decomposed products thereof, and 0.5 to 20% (W /
W) Addition is suitable. Other saccharides include juran gum (versus rice; (W / W) 0.1-5.0%), hyaluronic acid (0.05-0.8%), and anhydroic acid (0.3).
~ 3.0%), dextrin acid (0.5 ~ 20%),
Oligosaccharides (0.5-20%) are good. Trehalose, lactitol, maltitol, and sorbitol are effective for sugar alcohols, and the amount of these added is 0.1% for raw rice.
-10% is suitable.

As the emulsifier, it is effective to add sucrose fatty acid ester, polyglycerin fatty acid ester, organic acid monoglyceride, lysolecithin, diglycerin fatty acid ester. The addition of (W / W) is effective.

Among these additives, one of the reasons that the effect of adding salts is particularly large, and that the quality of rice cooked food to which the above-mentioned seasoning is added is smaller than that of white rice when naturally thawed is as follows.
This is considered to be the effect of adding the salts. In other words, sushi and onigiri are usually added with Na salt and the like, and it is considered that the effects of these salts have higher aging resistance than white rice.

These salts have sufficient effects when added at a concentration that does not cause a problem in taste. This is clear from the fact that, as can be seen from the examples of sushi and onigiri, the effect can be sufficiently obtained by using a general concentration for the purpose of seasoning. Furthermore, even in view of the size of the product which affects the thawing speed, morphologically small sushi is particularly suitable for this unheated thawing cooked rice food. Among the types of salts, Ca salts are particularly effective, and the desired effect can be obtained at a concentration of 0.05% or more, preferably 2.0% or more based on the total weight. The effect of the salts can be obtained either before processing or after processing. For example, when added to a rice immersion liquid after washing rice, or when added as a solid to cooked rice, a texture retention effect can be obtained in any case.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments. The present invention is not limited by these examples.

Example 1 Examples of product types and packaging effects Koshihikari cooked by a conventional method using a commercially available electric rice cooker was used as white rice, rice ball, and sushi. 10 for sushi
Individual pieces were packed in a plastic tray, packed in a plastic bag and packed under reduced pressure, and as a control, a sheet double-wrapped with a filter paper and wrapped was used (pneumatic packing). In addition, a sample of vacuum packaging was similarly prepared for the rice balls. After freezing these samples at -35 ° C, they were naturally thawed at room temperature and evaluated by sensory evaluation. The sensory evaluation was carried out by a rice specialty panel based on Koshihikari cooked with 1.2 times the amount of water. In the evaluation, the same grade as the standard was rated as 〇, slightly poorer was rated as △, and poorer was rated as ×.

[0019]

[Table 1]

The quality after thawing differs depending on the product.
In other words, the quality of the white rice was different from the quality before freezing, and the panel described it as edible. However, onigiri was better than white rice, and sushi was better than rice. The sushi was the easiest to maintain the quality after thawing, followed by rice balls and white rice. Furthermore, the effect of vacuum packaging on sushi was examined. As a result, gloss and transparency were improved by vacuum packaging, and a soft and sticky product was obtained.

Example 2 Relationship between thawing speed and quality Samples prepared in the same manner as in Example 1 were frozen at -35 ° C, thawed and stored under the conditions shown in the table below, and used for sensory evaluation. Provided. The evaluation was performed as shown below.
0) and appearance (x to Δ).

Texture: 0. Powdery appearance: xx. Obviously white wax 1. X. 1. White wax is observed. Δ. 2. Slight waxing is observed. Hard and tattered 〇. 3. No white waxing is observed. 5. Edible limit 6. 7. 7. Enough edible 9. 10.

[0023]

[Table 2]

The longer the transit time from -5 ° C. to 0 ° C., the greater the deterioration of texture and the appearance of white wax, and the lower the quality of sushi, the smaller the quality of sushi compared to white rice.

[0025]

According to the present invention, there can be provided a frozen cooked rice food product which can be thawed without heating and can maintain the quality before freezing even after thawing.

Claims (9)

[Claims] 1. A cooked rice food using cooked rice made of polished rice, which can be eaten naturally by thawing in a temperature range of room temperature or higher. 2. The frozen cooked rice food which can be thawed without heating as claimed in claim 1, which is a cooked rice food in a molded form. 3. The frozen cooked rice food product which can be unheated and thawed according to claim 1 or 2, which is packaged under reduced pressure. 4. The frozen cooked rice food which can be unheated and thawed according to claim 3, wherein the cooked rice food is packaged so as to be tightly accommodated. 5. The frozen cooked rice food which can be unheated and thawed according to any one of claims 1 to 4, wherein the cooked rice food is added with a seasoning. 6. The frozen cooked rice food that can be thawed without heating, according to claim 5, wherein the cooked rice food is sushi. 7. The frozen cooked rice food product which can be thawed without heating, according to claim 1, which is cooked rice containing a food additive. 8. The frozen cooked rice food according to claim 7, wherein the food additive is a salt. 9. The frozen cooked rice food product according to claim 8, wherein the salt is a Ca salt.