Method for manufacturing low-protein dried α-rice

Abstract

We provide low-protein dried pre-gelatinized rice that can be used as emergency or portable food for people with dietary restrictions, such as those with kidney disease. [Solution] Protein-adjusted rice or a processed product thereof, in which the protein content has been reduced by either lactic acid fermentation or protease treatment, is steamed to gelatinize it; the gelatinized protein-adjusted rice after the steaming process is immersed in water for washing and cooling; and the gelatinized protein-adjusted rice after the immersion process is dried at a high temperature. These steps are performed sequentially.

Description

Technical Field

[0001] The present invention relates to a method for producing low-protein dried gelatinized rice.

Background Art

[0002] As a means of obtaining cooked rice with reduced protein for those who need dietary restrictions such as patients with kidney disease, it is known to produce low-protein, low-potassium and low-phosphorus rice by subjecting raw rice to enzymatic treatment or lactic acid fermentation treatment (Patent Documents 1 and 2). Also, as emergency rice for disasters, dried gelatinized rice that is easy to process for consumption is suitable, but low-protein dried gelatinized rice is not currently available on the market.

[0003] Also, as a type of dried gelatinized rice, Patent Document 3 discloses a method of increasing the milling ratio of raw rice, removing the entire outer layer and part of the inner layer of the rice grains by milling, reducing potassium, phosphorus, and protein, boiling and gelatinizing it while stirring, and washing and drying the gelatinized rice (low-electrolyte gelatinized rice) to obtain low-electrolyte dried gelatinized rice.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The low-electrolyte dried gelatinized rice disclosed in Patent Document 3 merely increases the milling ratio of raw rice (60% milling) and simply removes the outer layer of the rice grains that contains a lot of protein. It is just rice with a lot of starch, and the flavor of the rice during eating is less. Also, the reduction of protein content only achieves a reduction of 1 / 3 to 1 / 2 of the protein.

[0006] Furthermore, protein-modified rice, which has been treated with enzymes or fermentation, is difficult to process for drying and gelatinizing using conventional methods (cooking and drying). This is because it contains less cellulose and pectin, which form the backbone of the rice grain. As a result, starch easily leaches out during the drying and gelatinizing process, making it difficult to maintain the shape of the rice grain.

[0007] Therefore, the present invention proposes a manufacturing method for novel low-protein dried pregelatinized rice that has good taste and is low in protein. [Means for solving the problem]

[0008] The present invention relates to a method for producing low-protein dried pregelatinized rice, characterized by sequentially performing the following steps: a steaming step in which protein-adjusted rice or a processed product thereof, in which the protein content has been reduced by either lactic acid fermentation treatment or protease treatment, is steamed to pregelatinize it; an immersion step in which the pregelatinized pregelatinized protein-adjusted rice after the steaming step is immersed in water for washing and cooling; and a drying step in which the pregelatinized protein-adjusted rice after the immersion step is dried at a high temperature.

[0009] Low-protein modified rice (white rice) is steamed and gelatinized, but in low-protein modified rice treated with lactic acid fermentation and protease, the pectin and cellulose that form the "skeleton of the rice" are broken down, so gelatinized starch easily dissolves from the surface of the rice after steaming. Even if high-temperature drying is performed as is, the gelatinized starch on the surface hardens into a film, preventing the maintenance of the rice shape and proper drying of the inside. The present invention washes the gelatinized starch off the surface of protein-modified rice that has been gelatinized by steaming, and then cools it to make it difficult for the gelatinized starch inside to dissolve, and then dries it at high temperature to obtain dried gelatinized rice that retains its shape. [Effects of the Invention]

[0010] As described above, the present invention provides low-protein dried pre-gelatinized rice for use as emergency food supplies or portable food for people who need to be mindful of their dietary restrictions during disasters. Low protein dried pregelatinized rice [Brief explanation of the drawing]

[0011] [Figure 1] Diagram illustrating the manufacturing process of the present invention. [Modes for carrying out the invention]

[0012] Next, embodiments of the present invention will be described. The present invention processes a predetermined protein-adjusted rice, and involves sequentially performing a steaming process, a soaking process, and a drying process.

[0013] Protein-modified rice is obtained by reducing the protein content through lactic acid fermentation, protease treatment, or both. Specifically, as disclosed in Japanese Patent Publication No. 2010-252714, filed by the applicant in this case, raw rice is disinfected and washed as required, then immersed in a preparation solution containing lactic acid bacteria and proteolytic enzymes, fermented under specified conditions, and after fermentation, washed with water to remove excess material. The protein content is reduced to 1 / 5 to 1 / 40 of that of the raw rice (a reduction of 80 to 97.5%).

[0014] Furthermore, the process may also involve simply immersing raw rice in a protein-degrading enzyme-containing solution to remove protein, resulting in a protein content reduction of approximately 20% compared to the raw rice. Moreover, this invention is not limited to protein-modified rice; it can also apply to processed protein-modified rice products. For example, since protein-modified rice itself is brittle, processed products such as steamed and dried protein-modified rice grains for cooking, which are then marketed, are also subject to the drying and gelatinization process.

[0015] The steaming process involves steaming the protein-modified rice using conventional methods to completely gelatinize the starch. The soaking process involves immersing the gelatinized protein-modified rice, which has finished the steaming process, in water at 5-30°C to cool it down, stopping the outflow of gelatinized starch from inside the rice grains, and then washing it to remove the gelatinized starch from the surface of the rice grains.

[0016] The drying process involves spreading the surface-washed, pregelatinized rice onto a perforated stainless steel plate, draining the water, and drying it for 45 minutes at a high temperature of 145°C with a large volume of air. The moisture content after drying is approximately 5-10%.

[0017] In the drying process, when regular pregelatinized rice is exposed to high-temperature air at 120°C, browning begins due to the oils and proteins it contains. However, pregelatinized protein-adjusted rice contains very little oil and protein, allowing for rapid drying at high temperatures. Furthermore, since high temperatures above 170°C tend to cause charring of the starch, the drying time and temperature should be adjusted within the range of 105-170°C while visually monitoring the condition of the pregelatinized protein-adjusted rice during the drying process.

[0018] The low-protein dried pre-gelatinized rice produced can be reconstituted with water or hot water, just like regular dried pre-gelatinized rice, and can be provided as emergency or portable food for people with dietary restrictions, such as those with kidney disease.

Claims

1. A steaming process in which protein-modified rice or a processed product thereof, in which the protein content has been reduced by either lactic acid fermentation or protease treatment, or both, is steamed and gelatinized, The immersion step involves immersing the gelatinized, gelatinized protein-adjusted rice after the steaming process in water for washing and cooling. Drying process: Drying the pregelatinized protein-adjusted rice after the soaking process at a high temperature. A method for producing low-protein dried pregelatinized rice, characterized by sequentially performing the following steps.

2. A method for producing low-protein dried pregelatinized rice according to claim 1, wherein the protein-modified rice has a protein content reduced by 20% or more relative to the raw rice.

3. The method for producing low-protein dried pregelatinized rice according to claim 1 or 2, wherein the soaking step involves washing off excess gelatinized starch from the surface of the protein-modified rice using water at 5 to 30°C and then cooling the rice.

4. A method for producing low-protein dried pregelatinized rice according to any one of claims 1 to 3, wherein the drying step is performed by drying with hot air at 105 to 170°C so that the moisture content is in the range of 5 to 15%.

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