JPS647740B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a rice cooking method and an apparatus thereof, and more particularly to a simple rice cooking method for cooking rice using a simple process different from the already established traditional rice cooking method. It is. Conventional technology The method of cooking rice, that is, cooking rice, is one of the ancient traditions of Japan, and is a well-known technique that has been established both empirically and in research. Many books on cooking rice have been published. Relatively recent representative works include Shiro Kawashima's ``The Science of Cooking,'' published by Koseikan in June 1976, and Fumio Kurasawa's ``Rice and Its Processing'' (Latest Food Processing Structure) published by Kenpakusha in November 1982. Publication can be mentioned. The above-mentioned book ``Rice and Its Processing'', pages 66 to 66
If you refer to page 71 and quote the basic idea of ``rice cooking'' and the main points of the basic rice cooking method, you will find the following statement. (1) Meaning of cooking rice. ``Cooking delicious food'' is something that is important to us Japanese people. Usually, we say ``cook the rice,'' and ``boil the potatoes.'' “Boiling” refers to the phenomenon in which water remains at the bottom of the pot until the end of cooking. ``Cooking'' means that the water disappears from the bottom of the pot, and is rather roasted. In other words, the soup is boiled over a fire and concentrated. This point is important in cooking rice correctly. The rice cooking process basically has the following four stages. B. First, this is the period when the rice and water are separated and the hot water heated by conduction from the bottom of the pot convects between the rice grains and heats the rice grains. (b) This is the period when the starch in the rice becomes colloidal, so the convection of hot water stops and the starch gelatinizes inside the rice grains. C. During what is known as ``steaming,'' the water remaining between the rice grains and at the bottom of the pot evaporates and is absorbed into the center of the rice grains, at the same time as the rice is expanded and softened. D. This is the time when the water in the bottom of the pot is drained and heated, and the rice turns a light fox color all over the bottom, making it truly delicious. The above meaning of cooking rice is quoted from Kurasawa's book, and to summarize it more simply, it shows that the process of ``cooking rice'' basically consists of the following four steps. B. Time to heat the rice grains in boiling water. (b) The period when the amount of hot water decreases and the starch in the rice grains gelatinizes. C. The period when the boiling water runs out and the remaining water evaporates to steam the rice. D. Time to slightly overheat the bottom of the pot to remove moisture from the surface of the rice grains. (2) Method of cooking rice. Furthermore, the same book describes specific methods for cooking rice as described above, such as ``washing and soaking''.
3. “Water level and heat level” and “Cooking (steaming)”
Although each item is explained in detail, I will only refer to the main points here. B. Washing and immersion. As a preparatory step for heating rice in a rice cooker, the rice is washed with sufficient water and soaked in water to ensure that the rice grains absorb sufficient water. Rice grains absorb most of the water in the first 30 minutes. (b) Water level. As can be seen in the process of "cooking rice" mentioned above, when heating and gelatinizing the rice grains during cooking, the boiling water needs to almost completely disappear, so it is necessary to adjust the amount of water appropriately depending on the amount of rice.
Typically, water is added in an amount equal to 1.5 times the weight of rice. (We will not discuss changes due to rice varieties or storage periods here.) This is approximately 1.2 times the volume ratio for ordinary rice. C. Heat. To heat it, turn the heat on high until it boils, then lower the heat a little when it starts to boil and heat it for about 20 minutes.
Towards the end, turn the heat on high for about 30 seconds, then turn off the heat. D. Steaming Steaming involves leaving the rice at a high temperature for a certain period of time, and during this time it is expected that the moisture remaining between the rice grains will be absorbed and the rice grains will expand. This process, which is basically established as a conventional rice cooking method, is also an essential process for automatic rice cookers, as stated on page 73 of Mr. Kurasawa's book, as a precaution when using automatic rice cookers. ``Automatic rice cookers automatically heat the rice, but washing the rice before heating, soaking it in water, the amount of water, and steaming it after heating do not necessarily work automatically, so be careful when operating these points. It is also understood that "there is a need." Problems to be Solved by the Invention The rice cooking method is an established technology as described above, and even with electric or gas automatic rice cookers that have become popular in recent years, it is difficult to improve the conventional basic rice cooking process. It is also a well-known fact that this device was created as a result of research into how to automate it faithfully. However, it is not always easy for ordinary housewives to use the rice cooking method that has already been established as described above, even for ordinary housewives who use a regular rice cooker. However, it is unavoidable that some operations are still required to adjust the metering. The applicant will clearly indicate in the following section of the object of the invention what problems the applicant intends to solve in the rice cooking method that has been thoroughly researched in this way. OBJECTS OF THE INVENTION The general purpose of the present invention is to provide a novel method and apparatus that allow anyone to easily and skillfully cook good cooked rice. If the purpose of the present invention is to be described in relation to the process of "cooking rice", it is of course not deviating from the conventional principle of cooking rice grains into rice, but it includes the above-mentioned four steps (heating with boiling water, starch of rice grains). The process of steaming rice, steaming the rice, and removing water from the surface of the rice grains) is apparently shortened to a one-step operation called ``Yunini'' (boiling in boiling water). For this purpose, a container with pores,
As will be explained later, a heat-resistant and pressure-resistant plastic bag is typically used. Furthermore, the purpose of the present invention is to provide "essential items for rice cooking method"
In relation to this, "washing and soaking" refers to the container-packed (typically bag-packed, hereinafter the same) of the present invention.
Although it is necessary to prepare the rice for the rice cooking process even if the rice grains are small, there is a difference from the conventional method in relation to the subsequent heating process using boiling water in the rice cooker. To provide a rice cooking method that does not require using an appropriate amount of water depending on the amount. In other words, the rice grains heated with boiling water in the bag expand their own volume to fill the internal volume of the bag and generate an appropriate internal pressure, thereby discharging the hot water present in the gaps between the rice grains. This is a rice cooking method in which the rice inside the bag is prevented from further swelling and softening by removing it from the pores of the bag. Furthermore, it is an object of the present invention to provide a rice cooking method that does not require "heat control", which is an essential item in the past. There is no problem. Furthermore, the object of the present invention is to distribute cooked rice into certain lump-like units, such as "onigiri", for example.
To provide ``onigiri''-shaped rice that can be hygienically cooked in ``onigiri'' shape as one unit of rice packed in a bag without having to be compacted by hand. Still another object of the present invention is to provide rice ball-shaped rice that is not only mixed with boiled rice but also contains ingredients such as barley or suitable dried food. Means for Solving the Problems The configuration of the present invention for achieving the above-mentioned objects of the present invention and for easily and skillfully cooking bagged rice will be described. B. Preparation of bags (or unit containers). A heat-resistant and substantially non-expandable plastic film bag is made, and a large number of small holes are made on almost the entire surface of the bag to prevent rice grains from passing through it. The maximum internal volume of the bag is determined as described in the next section in relation to the amount of rice to be filled into the bag. (b) Determining the amount of rice to be filled. The amount of rice filled in one bag must not be less than the amount that will at least fill the internal volume of the bag when the rice in the bag is cooked. In other words, the maximum internal volume of the bag mentioned in the previous section is designed to be such a limited volume that when the rice in the bag is cooked, pressure is applied to the cooked rice to suppress its free expansion. C. Consideration of rice brand, storage date, etc. The relationship between the amount of rice (weight or volume) and the amount of cooked rice (weight or volume) varies considerably depending on the quality of the rice, even for a given bag, so it is important to fill the bag. The amount of rice to be produced cannot be determined solely by calculation; it is necessary to conduct preliminary tests (trial cooking) for each production lot. D. Cooking process for rice in bags (or containers). Soaking in water as a preparation process for cooking rice requires 30 minutes or more, but in reality this process may be done in advance by the retailer, or even if the end consumer has time to do it. You can also immerse it in water or drain it and store it in the refrigerator, so you can adjust the so-called water level.
In the case of the present invention, the heating operation corresponding to the conventional "cooking rice" process, which requires heating and steaming steps, can be completed by "simply boiling water-soaked rice in a bag" in boiling water. I can do it. Function As will be described later regarding the embodiments of the present invention, for example, when about 40 g of rice is placed in a bag, the maximum thickness of the rice grain layer in the bag is about 3 cm, so the water-soaked rice in the bag is When rice is poured into boiling water, the depth at which the hot water penetrates into the rice grain layer through the holes in the bag is about 1.5 cm or less. This is thought to mean that the heating of the rice grains progresses much more rapidly than in the case of a general rice cooker, in which a group of rice grains housed in the entire rice cooker is heated from room temperature until the boiling point is reached. By boiling rice in a bag in boiling water in this way, it gelatinizes and expands in about 15 minutes, filling the inner volume of the bag. Since the bag is made of a heat resistant and substantially non-expandable material (as described in the Examples), the rice grains are prevented from further free expansion, so that the hot water present in the interstices between the rice grains is Due to the expansion force of the rice grains, they are pushed out of the bag and into the hot water through numerous small holes. Therefore,
The rice grains in the bag are already in the rice state, and at the same time, there is no boiling water that comes into contact with the rice grains to soften the rice any further, so the rice automatically transitions to the "steamed" state. It turns out. This means that
“Water level” is essential in the conventional rice cooking process.
In other words, the rice inside the bag is "cooked" in boiling water, and at the same time, it is heated by "boiling water extrusion" action based on the pre-designed relationship between the inner volume of the bag and the expansion rate of the rice. , it is understood that the conventional "watering down" effect is achieved. The strength of this "boiling water extrusion" action means adjusting the water absorption rate of the cooked rice inside the bag, so it can be used as a means to arbitrarily adjust the hardness or softness of the cooked rice. By appropriately designing the amount of rice to be filled with respect to the maximum internal volume of the bag (which varies depending on the quality of the rice as mentioned above), the quality of the cooked rice can be adjusted to the consistency of your preference. It means that you can. On the other hand, the "temperature" (details are as mentioned above), which was considered the most important in the conventional rice cooking process, is not necessary in the present invention, and heating does not necessarily have to start from room temperature each time; Once boiling water has reached a boiling state, there is no problem in continuing to boil it as it is, and once a large number of bags of rice have been boiled for about 15 minutes each (so-called boiling state), scoop them out one by one with a ladle. This allows you to cook a large number of bags of rice without having to adjust the heat at all. It can be seen that the rice in a bag that has been removed from boiling water can be made into a good ``rice ball''-like rice because its residual heat dries the moisture on the outside without any further heating. It should be noted that the bagged rice of the present invention can be mixed with any amount of barley or mixed with any ingredients, and in that case, the expansion rate will be different from that of rice alone. The relationship between the bag volume and the filling amount is a "test cooking"
Of course, it should be determined by Above, an overview of the quick and simple rice cooking method and device according to the present invention has been described, but in order to more fully understand the present invention, preferred embodiments thereof will be specifically explained in detail below. Examples As can be understood from the above explanation, in specifically explaining the examples of the present invention, we will not only show the cooking results of already adjusted bagged rice, but also It is necessary to show the results of "trial cooking" for the purchased lot of rice to determine the appropriate amount to fill in bags. B. Preparation of bags (or containers). Figure 1 shows the outer shape of the bag used. It is a composite laminate film bag 1 with a thickness of 39μ, consisting of a polyethylene film on the inside and a polyester film on the outside, and the three sides 3 other than the opening 2 at the top are inside. It is welded with polyethylene. A large number of small holes 4 (in the example, 42 small holes with a diameter of 2 mm) are made on both sides to the extent that no rice grains can pass through. FIG. 4 shows an example of a cylindrical container, which is composed of a main body 8 and a lid 9 screwed onto the main body 8. The maximum internal volume of the bag is determined to be, for example, approximately 76 cm ³ by a full-water test before the holes are punched. (b) Actual measurements of the sample rice. Since the measurement method is obvious, it will be omitted, but the average value will be shown. Brand Koshihikari Apparent specific gravity Average 0.82 g/cm ³ True specific gravity Average 1.45 g/cm ³ Water absorption rate after soaking in water Average 28% Apparent volumetric expansion rate after soaking in water Average 35% C Rice same as the test rice ( Actual measurements of rice (Koshihikari) cooked normally. The average weight of 100g of test rice (Koshihikari) cooked normally was 228g. This value is
This agrees with the common theory that the weight increase rate due to rice cooking is usually 2.2 to 2.4 times. It was also confirmed through "trial cooking" described later that it is desirable that the weight increase rate of the bagged cooked rice according to the present invention is in the range of 2.2 to 2.4 times. In this case, put this 228g of rice into a 500c.c. measuring cylinder (weight 364g), add 200c.c. of water and stir, and the liquid level after removing air bubbles between the rice grains is 398c. Since .c. is shown, the true specific gravity of rice is 1.15
An exemplary measurement value of g/cm ³ was obtained. D. Determining the amount of rice to be filled into the bag. The amount of rice filled in the bag (Figure 1) was determined by a so-called "trial cooking" test.
Six types were prepared: 25g, 30g, 35g, 40g, 45g, and 50g. Figure 2 shows the opening 6 filled with rice 5.
This shows the state where the is sealed by heat welding. Since the sample rice has been polished in advance, the rice in the bag is thoroughly soaked in water and then placed in boiling water in a suitable boiling pot. After about 15 minutes, the six types of rice in bags are heated, swollen, and gelatinized by the heating of the water in the bags and the intrusion of hot water in the pot, and the interaction between their own expansion and the limited volume inside the bags. This forces the free hot water between the rice grains out of the bag, and the rice grains automatically undergo an action that approximates a "steamed" state. FIG. 3 is an exemplary diagram showing the appearance of the bagged rice 5 that has been cooked in this manner. As a result of the test, the weight increase ratio of each sample was calculated and displayed as follows. However, in this table, the first example is the result using a bag manufactured at a certain time, and the second example is the result after the thickness of the composite film of the bag was changed to 45μ and the expansion resistance was improved. The results show the results using an increased number of bags, and the significance of conducting "trial cooking" for each product lot can be understood from these results.

【table】

[Table] Fig. 5 shows cross-sectional shapes for comparing the expansion states of six types of rice packed in test bags from 25g to 50g in the first example after boiling. Figure 6 shows the "trial cooking" of the first and second examples, where the horizontal axis is the amount of rice filled in g, and the vertical axis is the net weight of rice after cooking, g.
It is a diagram showing a curve and straight lines R ₁ , R ₂ , R ₃ , and R ₀ passing through the origin and showing four examples of the weight increase rate of cooked rice due to the difference in the amount of water in normal rice cooking. In both the first and second "trial cooking" cases, the results of the tasting revealed that the rice had an appropriate hardness with a weight increase ratio in the range of 2.2 to 2.4. That is, in the bag of the first example, the amount of rice to be filled is 37g to 42g, and if there is some margin, 35g to 45g is appropriate, and the actual selected value may be 40g. In addition, in the second example bag, the composite film was made stronger, so
The range of weight increase ratio 2.2 to 2.4 is narrower than in the first example, and the actual determined value is 33g to 37g.
It weighed 35g. Effects of the Invention It can be said that the achievement of the matters listed in the above-mentioned "Objectives of the Invention" is an effect of the invention, and the matters explained in "Operations" are characteristics of the present invention. In this section of "Effects of the Invention", in order to further clarify the features of the present invention, a "trial cooking" curve diagram (Fig. 6) is presented.
We will explain the unique effects that can be understood from the following. In FIG. 6, straight lines R ₂ and R ₁ indicate that the range of increase in weight of rice in normal rice cooking is 2.2 times to 2.4 times, and since good rice is generally within this range, the present invention Rice also follows these two straight lines.
It is understood that it is best to be in the area between R ₁ and R ₂ . In the bag of the second example, the amount of rice to be filled is preferably 33g to 37g, but depending on the preference for softness or hardness of the rice, a range of about 30g to 40g may be acceptable. In addition, the straight line R ₀ is a line with a weight increase factor of 3.0,
It can be seen that when the amount of rice filled is small, the weight increase ratio is almost on the line of 3.0. this is,
When the amount of rice filled is too small, there is almost no compression force generated by the bag that suppresses the expansion of the rice grains even after cooking by boiling, the rice grains freely expand and become soft, and free hot water remains inside the bag. Because it is,
This can be confirmed by the fact that hot water drips when the No. 1 bag is actually lifted out of the boiling water, and the cooked rice in the bag is too soft and the pressure due to the limited volume according to the present invention is No conjunctive effects were observed. In the above-mentioned "test cooking", the judgment is of course mainly based on the tasting, but the judgment can be aided by physical measurement values. In other words, the weight increase ratio of 2.2 to 2.4 is the reference value for the above-mentioned sample rice Koshihikari (true specific gravity 1.45), which also corresponds to 1.145 to 1.165 when measuring the true specific gravity of cooked rice.
It can also be determined by the following. The following relational expression holds true between the true specific gravity of rice S, the true specific gravity of rice D, and the weight increase rate R due to cooking, so it can be used for mutual conversion or for comparing actual measured values and calculated values. . Considering 1 cm ³ of rice, true specific gravity of rice = weight of rice / volume of rice = specific gravity of rice x weight increase rate / volume of rice + water absorption ∴ S = DR / 1 + D (R - 1) Therefore, for example, the above The hardness of rice was determined by calculation for sample Nos. 4 and 6, which had good rice hardness in the second example, and was 1.147 and 1.147, respectively.
1.179 was obtained, which almost coincides with the above measured value, so that the result of the trial cooking can be judged objectively. As the filling amount of rice gradually increases, the compacting effect of cooked rice due to the limited volume of the bag according to the present invention becomes more noticeable, and as the filling amount of rice increases, the rate of increase in the net weight of cooked rice decreases. The curve shown was obtained. In other words, in normal rice cooking, which does not cause compaction of rice due to the limited volume of the container, as the amount of rice increases, the weight of cooked rice of the same softness is directly proportional to it. It is clear that each straight line R ₀ , R _{1 .} . . in FIG. 6 is a straight line passing through the origin. On the other hand, in the method of cooking rice in a container according to the present invention, it can be understood from the "trial cooking" curve that the larger the amount of rice filled, the smaller the proportion of cooked rice is due to the compaction effect of the container. To make this point even clearer, if we plot the "increase in weight g due to rice cooking" in the "trial cooking" report in Figure 6, we can see that
For the example, characteristic curves are obtained which, as the filling amount g of rice increases, pass through certain maximum values P ₁ and P ₂ and then decrease again, as indicated by the dotted lines in each case. In this way, even though the amount of rice filled in a container (typically a bag) of a certain constant volume is gradually increased, the increase in weight due to rice cooking reaches a certain maximum value and then decreases. This indicates that the compression of rice cooking, which is a feature of the present invention, begins to work effectively near the maximum value. Therefore, the filling amount of rice corresponding to these maximum weight increases (35g in the first example, 30g in the second example)
It is understood that g) can be used as a criterion (minimum value of the rice filling amount range for obtaining good cooked rice) objectively obtained from the "trial cooking" data. The cross section of the bag shows that the more rice is filled, the more pressurized the rice is, as shown in Figure 5. The product of the present invention is also extremely hygienic, as it is possible to take out the "rice ball"-shaped rice from the bag and eat it by tearing the notch 7 previously provided in the bag, unlike rice balls that are held by hand. This is one advantage. In the above explanation, the amount of rice filled is expressed in terms of weight (g), but in actual handling, the volume of rice is cm ³
It goes without saying that there is no problem in expressing it as (or ml). The present applicant has filed a patent application for the same basic idea as the present invention in Patent Application No. 165799 filed in 1982, ``Method for manufacturing containerized rice, and containers and products therefor''; Since there is still a lack of sufficient description to enable one to understand the true spirit of the patent, we have hereby filed a new application that includes a detailed description and clear claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view illustrating a perforated plastic bag used for the simple rice cooking of the present invention, FIG. 2 is a perspective view showing the bag in FIG. 1 filled with rice, and FIG.
The figure is an illustrative diagram showing the appearance of cooked rice in a bag,
FIG. 4 is a perspective view illustrating a cylindrical container, FIG. 5 is a conceptual cross-sectional view for comparing the expansion state after boiling of bags of rice filled with different amounts of rice, and FIG. 6 is a FIG. 3 is a diagram showing a "trial cooking" curve for determining the optimum amount of rice to be filled. 1...Composite laminate bag, 2...Bag opening,
3... Welded side of the bag, 4... Numerous small holes in the bag, 5
...Filled rice, 6...Welded bag opening,
7... Tear cut in the bag, 8... Cylindrical container body, 9... Cylindrical container lid.

Claims (1)

[Claims] 1. A step of filling a heat-resistant container having a plurality of small through-holes large enough to prevent rice grains from passing therethrough with an appropriate amount of rice and closing the filling opening; The method includes a step of impregnating rice with water, and a step of boiling the rice impregnated with water in the container in boiling water to cook the rice in the container, and the rice filled in the container is , during the boiling step,
Due to the interaction between its gelatinization expansion and the limited volume of the container, it compacts itself in the container and drains the excess free water between the rice grains into the boiling water, forming good cooked rice and increasing the volume of rice in the container. The amount of rice to be filled is determined by the maximum value of the weight increase curve obtained by "trial cooking" performed in accordance with the above process by filling different amounts of rice into multiple containers of a certain constant volume. A simple rice cooking method characterized in that the corresponding filling amount is set as the minimum value of the appropriate filling amount range, and the amount is sequentially increased from the minimum value according to the desired hardness of cooked rice. 2. The simple rice cooking method according to claim 1, wherein the appropriate range of the rice filling amount corresponds to a weight increase rate due to rice cooking of 2.2 to 2.4. 3. The simple rice cooking method according to claim 1, wherein the rice is packed in a heat-resistant, non-expandable, porous plastic container. 4 The boiling process of boiling rice in a porous container in boiling water is a patent that includes the steps of sequentially placing a plurality of containers filled with rice into boiling water and sequentially scooping out the containers containing the cooked rice. A simple rice cooking method according to claim 1. 5. The simple rice cooking method according to claim 1, wherein the porous plastic container is formed in a bag shape. 6. The simple rice cooking method according to claim 1, wherein the porous plastic container is formed in a cylindrical shape. 7. The simple rice cooking method according to claim 1, wherein optional ingredients are mixed into the rice in the porous plastic container.