JPH0370464B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing natto containing barley that has excellent flavor and texture. BACKGROUND ART With the development of health-oriented foods, attempts have been made to mix various foods into natto. Regarding barley, for example, JP-A-54-67057, JP-A-56
- Natto containing barley is known, such as in Publication No. 154964. The conventional method for producing natto with barley is to mix soybeans with washed barley or rolled oats, soak them in water, drain the water, and steam them. Then, the mixture is sprinkled with starter bacteria and fermented. This is where you get natto. Problems to be Solved by the Invention When soybeans and barley are mixed and steamed as in the past, heating the soybeans under conditions that impart appropriate softness to the soybeans results in the hardness of the barley, since barley has a hard structure among grains. This is undesirable because it leaves a sticky residue and the resulting product has a poor texture. Also, if you use pressed rolled barley and steam it in the same way, the rolled barley will become sticky, especially if you do not mix the soybeans and rolled barley evenly before steaming, the rolled barley will adhere to each other and form blocks, allowing the soybeans to be cooked evenly. There were drawbacks such as the inability to mix. Means for Solving the Problems The inventors of the present invention are considering a method for processing barley. Just by soaking the heated barley in water, it absorbs enough water to swell, soften, and become edible.
We learned that when mixed with steamed soybeans, they can be mixed evenly and easily without sticking to each other, and that when fermented by ingesting starter bacteria into this mixture, natto with excellent flavor and texture can be obtained, and we have invented the present invention. completed. That is, when producing natto, the present invention involves heating barley under pressure using saturated steam of 2 Kg/cm ² G or more and 6 Kg/cm ² G or less, and then gradually decomposing it. This method of producing natto is characterized by mixing pressure-heated barley obtained by pressing with steamed soybeans. The present invention will be explained in detail below. The barley used in the present invention may be either coated barley, in which the husk does not easily come off, or naked barley, in which the husk comes off easily and the grains come off easily, and either brown barley or refined barley may be used. When using brown barley, whitening may be performed after pressure heating. Then, the barley is heat-treated as it is without soaking in water using saturated steam at a pressure of 2 kg/cm ² ·G or more and 6 kg/cm ² ·G or less for 30 seconds or more and 20 minutes or less. The above pressure and heat treatment conditions are appropriately selected within the above pressure and time ranges, taking into consideration the degree of gelatinization, swelling degree, hardness, etc. of the barley after the pressure and heat treatment.
If the temperature is less than Kg/ ^cm2・G or the heating time is less than 30 seconds, the degree of gelatinization of the pressure-heated barley obtained will not increase, and it will be hard and have a low degree of swelling, and therefore it will not be possible to mix it with steamed soybeans after soaking in water. Even if natto is produced using this method, the barley is hard and does not swell, resulting in a poor texture.
On the other hand, pressure-heated barley obtained at a pressure of 6 kg/cm ² G and a heating time of more than 20 minutes will be colored or burnt, resulting in only natto with a dark color, burnt odor, and bitter taste. . The pressurizing and heating apparatus used in the present invention may be of any shape or structure, regardless of whether it is a continuous type or a batch type. Further, the saturated steam used in the present invention can be used without any problem as long as it does not contain any air or contains a water amount of air. Next, after the barley is pressurized and heated using saturated steam in this manner, the pressure is gradually decompressed and the barley particles are discharged without swelling to obtain pressurized and heated barley. In this case, the pressure may be gradually decompressed to such an extent that it takes at least 10 seconds to return the barley to normal pressure after steaming it under pressure. Pressure-heated barley may be obtained by returning to pressure. This prevents the destruction of the barley tissue due to swelling, and when water is absorbed, the barley grain has appropriate interstitial elasticity, is less sticky, and is not sticky.
Pressure-heated barley that can be easily mixed with steamed soybeans is obtained. The pressure-heated barley obtained in this way is
After polishing if necessary, this is used to produce natto. First, pressure-heated barley is soaked in water for an appropriate period of time, for example overnight. The barley thus swollen by water absorption is added in an appropriate amount, preferably 10 to 50% (W/W), to steamed soybeans obtained by washing, soaking, draining, and steaming in a conventional manner and mixed. According to the present invention, the pressurized and heated barley has already undergone sufficient gelatinization and has swollen and softened, but it maintains elasticity and can be easily mixed with steamed soybeans without sticking to each other. can. Next, this mixture is inoculated with an inoculum. In this case, in normal natto production, the steamed high-temperature soybeans are cooled and then inoculated with starter bacteria, but in the method of the present invention, the cold, pressure-heated barley after soaking is mixed with the steamed high-temperature soybeans. This will lower the product temperature to an appropriate temperature, and cooling for seed inoculation is not necessary. After inoculation, the product is fermented in the usual manner. The present invention will be explained below with reference to experimental examples. Experimental Example 1 Wrap 100g of refined barley in cloth for each test section and place in a small horizontal autoclave (inner diameter: 150φ).
m/m, length 200 m/m), sealed and heated under pressure using saturated steam under the treatment conditions listed in Table 1, and then the steam pressure was released to obtain pressurized and heated refined barley. The pressure-heated white barley was washed with water, soaked in water for 16 hours, and drained to obtain pressure-heat soaked white barley. Table 1 shows the gelatinization degree of the pressure-heated whitened barley, the degree of swelling of the soaked whitened barley, the hardness, and the sensory evaluation. As a control, untreated rolled barley and milled barley were treated in the same manner as above after measuring the degree of gelatinization.

【table】

[Table] As shown in Table 1, refined barley is heated using saturated steam at a pressure of 2 Kg/cm ² G or higher and 6 Kg/cm ² G or lower.
As a result of treatment under various treatment conditions of 30 seconds or more and 20 minutes or less, pressure-heated white barley was obtained which had a sufficient degree of gelatinization and good digestibility, and which swelled and softened simply by soaking in water at room temperature. It became edible. Experimental Example 2 Natto was produced using each type of barley obtained by pressurizing and heating 150 g of refined barley per test plot in the same manner as in Experimental Example 1. First, 500 per test area
Soybeans (g) were soaked in 20°C water for 14 hours, allowed to absorb enough water, drained, and placed in an autoclave (manufactured by Sanei Seisakusho, diameter: 80cm, depth: 100cm) at a pressure of 0.7.
It was steamed for 30 minutes at Kg/cm ²・G. The pressure-heated white barley soaked in water for 14 hours and then drained was added to each of the obtained steamed soybeans and mixed, and Bacillus natto was inoculated at a temperature of about 60°C. Next, each of the above mixtures was poured into 100g containers prepared in advance at an initial temperature of 42°C, and after 6 to 8 hours, the mixture was heated to 48°C.
After reaching ℃, adjust the temperature to 45-48℃ and continue fermentation.
After aging for about 16 hours, the fermented soybeans were cooled to 5°C to obtain natto. The yield of each natto obtained, the hardness of the barley particles in the natto, and the sensory evaluation are shown in Table 2. As a control, 500g of soybeans and 150g of untreated rolled barley.
were washed separately, immersed in water for 14 hours, drained, and then mixed and steamed for 30 minutes at a pressure of 0.7 Kg/cm ² G. Test plots, 500 g of soybeans, and 150 g of untreated white barley.
Test plots treated in the same manner were selected, and after steaming, both test plots were cooled to 60°C and then inoculated with Bacillus natto. Thereafter, the same treatment as above was performed and the results are shown in Table 2.

[Table] As shown in Table 2, natto made by mixing each type of barley treated within the range of the treatment conditions of the present invention has a high yield of natto because the barley particles sufficiently absorb water and swell, and is also sensually unique to natto. The smell is faint and the color is white.
Despite being softened, it had appropriate elasticity, good flavor, and a good texture. On the other hand, refined barley mixed with soybeans and steamed has hard barley grains with little swelling, and products made using rolled barley have barley particles that adhere to each other and are difficult to mix uniformly with soybeans, resulting in a poor texture. It was hot. Examples Hereinafter, the present invention will be explained with reference to Examples. 5 kg of refined barley was wrapped in cloth and placed in a small horizontal autoclave (inner diameter: 150φm/m, depth: 200 m/m), sealed and heated under pressure for 4 minutes using saturated steam at a pressure of 4 kg/cm ² G. . Then, the exhaust valve was gradually opened and the pressure was lowered to atmospheric pressure in 30 seconds, yielding 5.05 kg of pressurized and heated refined barley. 5 kg of the pressure-heated white barley and 15 kg of soybeans were separately immersed in water at 20° C. for 15 hours to absorb sufficient water, and then drained. And autoclave only soybeans (manufactured by Sanei Seisakusho, diameter: 80cm, depth: 100cm)
and steamed for 30 minutes at a pressure of 1.0 kg/cm ² G. The refined barley that had been soaked and drained was added to the obtained steamed soybeans, mixed, and inoculated with Bacillus natto. Next, the mixture was divided into 100 g containers and fermented at 48°C for 16 hours, then cooled to 5°C to ripen, yielding 42 kg of natto. The obtained natto had no peculiar odor, was fair-skinned, had sufficiently swollen barley particles, and had a good flavor and texture. Effects of the Invention The natto obtained by mixing pressurized and heated barley according to the present invention is different from the conventional natto obtained by mixing and steaming soybeans because the barley is pre-pressurized and heated under optimal conditions. When used, it absorbs enough water, swells and softens just by soaking it in room temperature water, and has moderate elasticity, making it possible to mix evenly with steamed soybeans.In addition, it can mix hot soybeans and cold soybeans. By mixing, the temperature of the product is immediately lowered to an appropriate temperature, making it possible to inoculate the seed bacteria, thereby reducing the burden of cooling, which is required in the conventional method. The obtained natto does not have a peculiar odor, is not only white in color, but also has a high yield in both weight and volume, has good mycelium surroundings, has appropriate elasticity, and has good flavor and texture. I can do it.

Claims (1)

[Claims] 1 When producing natto, barley is 2Kg/cm ²・G
Above, using saturated water vapor of 6Kg/cm ²・G or less
A method for producing natto, which is characterized in that pressure-heated barley obtained by heating under pressure for at least 30 seconds and up to 20 minutes and then gradually decompressing is mixed with steamed soybeans.