JPS62198364A - Processing of soybean - Google Patents

Abstract

PURPOSE:To obtain seed leaves of soybean having improved taste, flavor and color tone and high NSI, by controlling water-content of a soybean, drying at a specific temperature, dividing into two and skinning the bean. CONSTITUTION:Water-content of soybean usually containing about 12-15% water is controlled to <=12%, preferably 8-12% and the moisture-controlled soybean is uniformly heated in a relatively short time at 70-80 deg.C to effect the uniform heating and drying of the surface of the soybean. The dried soybean is divided into two e.g., with a grinder having larger distance between grinding wheels than the particle diameter of the soybean. The divided soybean is cooled to <=30 deg.C and skinned by a skinning means.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for processing soybeans. More specifically, it provides soybean cotyledons with improved flavor and color development and high NSI (protein water solubility index), including isolated soybean protein, polysaccharides, oligosaccharides, soy milk, textured or fibrous, etc. The present invention provides soybean cotyledons that are excellent as raw materials for protein foods.

(Prior Art) Many methods have been known for peeling soybeans as raw materials for tofu and the like. Among them, methods for heating and peeling soybeans include, for example, Japanese Patent Application Laid-Open No. 56-84644.58-7.
1858.59-147647.59-150550.
59-150661 and the like.
The main difference between the present invention and the prior art is that the present invention adjusts the moisture content of soybeans to 12% or less in the process of sorting soybeans, heating and drying them, splitting them in half, peeling them, and sieving them to obtain soybean cotyledons. ,
The surface of the soybeans is uniformly heated and dried so that the temperature of the soybeans is between 70 and 80°C, facilitating molting and hypocotyl removal, and making fine powder (
The goal is to obtain high yields of soybean cotyledons that generate less grit and retain high NS.

(Problems to be Solved by the Invention) Soybeans are composed of skin, hypocotyls, and cotyledons, and dust and the like adhere to the skin, which deteriorates the color tone and flavor of soybean products (products obtained using soybeans). Furthermore, the hypocotyl contains a large amount of saponin and polyphenol compounds, which deteriorate the flavor of soybean products. Therefore, the present inventors removed these soybean hulls and soybean hypocotyls, and aimed to obtain soybean cotyledons that have improved flavor and color and retain high NSI.

In line with the above purpose, soybeans were split into two, and attempts were made to molt the soybeans and remove the hypocotyls. However, it is difficult to split (al) into two and remove the skin, (c) it is difficult to separate the hypocotyl and cotyledons, (c) it is difficult to separate the hypocotyl and cotyledons, and (c) it is difficult to separate the hypocotyls and cotyledons. )
We encountered a problem in which it was difficult to set conditions for molting and hypocotyl removal to maintain a high NSI of soybean cotyledon protein.

(Means for solving the problem) Conditions for obtaining soybean cotyledons by sorting raw soybeans, splitting them into two using a splitting means such as a grinder, wind-selecting, removing the skin, and sieving to achieve the above purpose. While conducting various studies on the temperature of soybeans, we discovered that soybeans, which usually contain about 12 to 15% moisture, were prepared by adjusting the soybean moisture content to 12% or less in advance, and measuring the soybean product temperature (measured with a temperature needle). (Actually measured temperature) is 70-80
By uniformly heating the soybeans in a relatively short period of time to a temperature of The skin is easily formed, (b) finely pulverized parts (grits) are difficult to form even when split in half and sieved, (0) the hypocotyl and cotyledons are easily separated, and (dl is split in half and sieved). The soybean cotyledon having some skin can be easily removed by using a peeling means, and (e) the NS and I of the soybean cotyledon protein that has been peeled and dehulled (dehulled) and hypocotyl can be increased. The present invention was completed based on the knowledge that can be maintained.

That is, the present invention involves adjusting the moisture content of soybeans to 12% or less, heating and drying the soybeans to a temperature of 70 to 80°C, and splitting the soybeans into two kudzu processes and peeling the split soybeans. This is a soybean processing method characterized by obtaining soybean cotyledons by combining the following.

As the soybeans used in the present invention, known soybeans can be used. Normally, raw soybeans contain immature beans, impurities, etc., so it is preferable to sort them to make the particle size uniform, which makes subsequent processing easier. As a method of sorting, known sorting means such as sieve sorting, roll sorting, wind sorting, density sorting, etc. can be used.

The present invention includes a step of adjusting the moisture content of soybeans to 12% or less;
It is characterized by combining the process of heating and drying the soybeans to a temperature of 70 to 80℃, and the process of splitting the dried soybeans in half and peeling the split soybeans (if they contain some skin). has. The purpose can be achieved by such a combination.

First, reduce the moisture content of soybeans to 12% or less (preferably 8 to 12%,
More preferably, it is adjusted to 10 to 1)%. Normally, soybeans contain 12-15% moisture, so they are slowly dried at low temperatures (usually 60-70℃) to reduce the soybean moisture to 1.
It can be adjusted to 2% or less. A water content of 8 to 12% is suitable for compressing the harvested cotyledons to extract soybean oil. When the soybean moisture content is less than 8%, the resulting soybean cotyledons tend to crumble when pressed, which is not preferable. Soybeans already within this moisture range do not require moisture adjustment. In addition, it is preferable to adjust the moisture content of soybeans with moisture content of less than 8% by humidifying the soybeans to 8 to 12%. Also, if the moisture content of soybeans exceeds 12%, they will split into two.
To adjust the moisture content of soybeans to 12% or less, which is undesirable due to poor skin removal, known drying methods can be used.6 For example, a ventilated vertical dryer, a countercurrent multi-stage dryer, a vented rotary dryer, etc. , the drying temperature is relatively low (usually 60-7
0° C.) and relatively slow drying time (usually about 30 to 60 minutes).

Next, it is important to dry the soybeans whose moisture content has been adjusted to 12% or less so that the temperature of the soybeans is 70 to 80°C. If the soybean p product temperature is less than 70°C, the heat drying and flexibility of the soybeans will not be sufficient, and grits will be generated in the next halving process, which will deteriorate the yield of soybean cotyledons, which is not preferable. Furthermore, if the soybean temperature exceeds 80°C, the NSt of the obtained soybean cotyledons will decrease, which is not preferable. Product temperature is 70
Soybeans at ~80°C are flexible enough to be split into two.
It can be crushed with less grit, makes peeling easier, and is NS! This is suitable because it does not cause a decrease in The moisture range in which soybeans maintain appropriate flexibility when heated to 70 to 80°C can be set to approximately 7 to 1%. If it is too dry, the soybean loses its flexibility when heated and tends to increase the generation of grits during the halving process.

Suitable drying means for maintaining appropriate flexibility inside the soybean and uniformly drying the surface of the soybean include, for example, fluidized bed drying, air bed, rotary kiln, etc. Drying is most suitable for uniform soybean surface drying.

For example, the conditions for fluidized bed drying are usually a hot air temperature of 80°C to 9°C.
Preferably, the temperature is 0°C, the temperature inside the layer is 75°C to 85°C, and the residence time is about 3 to 4 minutes, and the conditions can be changed as appropriate depending on the scale and purpose.

Next, the soybeans that have been dried and have appropriate internal flexibility and surface brittleness are split into two. A known coarse crusher (for example, a grinder, a rubber roll, a cranking roll, etc.) can be used to divide the mixture into two.

For example, when using a grinder, it is preferable to use a grinder with a grindstone spacing slightly wider than the soybean grain size. If a grinder with a grinding wheel spacing narrower than the grain size of the soybean is used, the soybean cannot be split into two properly, resulting in increased grit generation and poor cotyledon yield. Moreover, if the distance between the grinding wheels is too wide, the amount of unbroken soybeans will increase, which is not preferable.

For example, when splitting soybeans with a grain size of 6.5-φ into two, the appropriate spacing between grinding wheels is about 71III.

When splitting in two, it is better to prevent the soybean temperature from dropping, and even if it does, it is preferably 50°C or higher.0 If the temperature drops, the soybeans become hard and more grits tend to occur due to splitting. It is in.

Once the temperature drops, soybeans tend to become hard and difficult to split in half and remove the skin, so it is better to heat them again.

Furthermore, when using a grinder, the generation of grits tends to be reduced when the rotation speed of the grindstone is relatively low.

In addition, soybeans that have been split in half can be obtained by wind sorting, removing the hulls, and sieving. do not have)
can be repeated by dividing it into two parts again. Normally, it can be completely split into two by re-splitting process.

Breaking into two can be done in the same way as the above-mentioned splitting of soybeans into two.

For example, when a grinding die is used, the grain size of unsplit soybeans is usually about 5++a, so the spacing between the grinding wheels of the grinder is preferably about 5.5ta.

If the soybeans are to be split into two again, there is no need to separately heat and dry the unbroken soybeans.

The soybean split in two can be wind-selected to remove the skin, if desired, and sieved to remove hypocotyls and grits to obtain soybean cotyledons. Normally, the soybean cotyledons that have been split into two and sieved often still have about 20% of the skin attached (based on the skin of the whole soybean).
After cooling to below 0.degree. C. (preferably below 30.degree. C.), it is preferable to peel and remove the skin using a peeling means. As the peeling means, known means such as a grinder, a peeling machine, and hand kneading can be used. When using a grinder, it is preferable that the distance between the grinding wheels be wider than the diameter of the soybean particles split into two.

As the soybean cotyledon containing the skin is cooled, the peeling effect by the peeling means tends to increase, and when the temperature becomes 30° C. or lower, the peeling effect reaches approximately equilibrium. For example, from 60°C to 30°C, the peeling rate (weight ratio of peeled skin to whole soybean skin) tends to increase proportionally by about 8%.

In addition, the means of cooling can be any known means such as left cooling or forced cooling (for example, mechanical means such as a vibrating draft cooler or a rotary draft cooler).As mentioned above, there are two methods. The soybean cotyledon part obtained by cracking, peeling, and dehulling/dehypocotyl contains almost no skin or hypocotyl, and can be used as a soybean cotyledon that meets the purpose.

In addition, for the peeling after splitting into two or the peeling after peeling, known means (for example, Aspirator-1 wind classifier, etc.) can be used.

In addition, a known sieving machine (for example, a rotary shifter, a vibrating sieve, etc.) can be used for sieving after the above-mentioned halving.

The cotyledon obtained through the above process has a high yield (usually about 85% or more vs. 95% or more of soybean cotyledon vs. soybean cotyledon), has improved flavor and color, and has an extremely low degree of denaturation, so it is NSI. is high (NSI decline typically less than about 2%);
It is excellent as a raw material for protein foods such as isolated soy protein, polysaccharides, oligosaccharides, soy milk, and textured or fibrous protein foods.

(Example) Embodiments of the present invention will be described below with reference to Examples.

Example 1 American soybeans (moisture 12%) were grown in a 4.8 x 12 m
Sorted using a sieve with a mesh size of 6.6 m.
Soybeans with mφ (particle size 5.4 to 8.4 mm+φ) were obtained.

The selected soybeans were pre-dried (with hot air at 70°C for 30 minutes) to adjust the moisture content to 1%.

5000 parts by weight (hereinafter referred to as "parts") of soybeans with a moisture content of 1)% were heated with hot air at a speed of 3.4 m/secC using an experimental fluidized bed dryer.
The tofu was heated and dried under the conditions shown in Table 1, and immediately divided into two pieces using a grinder for manufacturing tofu (manufactured by Kurihara Iron Works) with a distance between grinding wheels of 7 mm, and then cut into two pieces using a wind classifier (wind speed 3 to 5).
Skin removal (288 parts) at m/sec > 4.3
The unsplit soybeans (500 parts) were sieved and fractionated using a 19+ms sieve, then split into two again using a grinder with a grinding wheel spacing of 5.5 m, and the skins were removed in the same way (39 parts). I caught a soybean split in two.

Split the soybeans in half and use an 8-mesh sieve to remove the cotyledon part (44
22 parts), hypocotyl part and grit part (total 250 parts).

The cotyledon part was cooled to 50°C using an asvil radar, passed through a grinder again (with a distance between grinding wheels of 12 cm), and was subjected to wind selection.
It was sieved to remove the skin part (66 parts) and guritara n (24 parts) to obtain 4324 parts of the cotyledon part.

Table 1 shows the dehulling rate, hypocotyl removal rate, and NSI of the obtained cotyledons of soybean.

(Left below) Table-1 Fluidized bed heating conditions and result No. 1 2 3 4 5 6 7
(A) 60 65 72 75 79 85 95
(B) 55 61 69 73 77 85 89
(C) 86.28B, 393.696,098.2
98,699.5 (D) 95.596,898,
099.298, 299.299.9 (E) 89
．． 089.689, 989.688, 686.579.
8 However, (8) is the heating drying temperature (heating time was 3 minutes), (B) is the soybean product temperature, (C) is the soybean dehulling rate *1,
(0) represents the hypocotyl removal rate *2, (I represents the NSI *2).

Also, *1 ; Soybean peeling rate (%) = 100
! 1ff of residual soybean hulls in the product) / (weight of sorted soybeans x
o, o.

) (Calculated assuming the percentage of soybean hulls is 8%.) *2: De-hypocotyl rate (%) = 100 Calculations were made assuming the proportion of soybean hypocotyl as 2.5%.) *3: sst is the proportion (%) of water-soluble protein to total protein, and was determined by a known measurement method.

Application Example 1 4000 parts by weight of cotyledons obtained in the same manner as No. 5 of Example 1 was pressed, extracted twice with n-hexane (10 times), air-dried, and defatted cotyledons (residual oil approximately 0 .5%) was adjusted. Add 10 times the amount of water to this defatted cotyledon, stir and extract at 40°C for 40 minutes, remove the okara, and the resulting soymilk is subjected to isoelectric precipitation (al14.5) using hydrochloric acid, and the resulting curd is The solution was neutralized with caustic soda to make a 10% solution, which was then subjected to UHT high-temperature instant sterilization (135°C for 10 seconds) and spray-dried to obtain isolated soybean protein.

Comparative Example 1 Soybeans were treated in the same manner as in Example 1 to prepare defatted soybeans, and soybeans were treated in the same manner as in Example 1 to obtain isolated soybean protein.

Experimental Example 1 The isolated soybean protein obtained in Example 1 and the isolated soybean protein obtained in Comparative Example 1 were each made into a 10% solution, and flavor etc. were tested by 10 panelists. The results are shown in Table-2.

Table-2 A B Astringency Less than B Bitterness More than A B
Less More astringent than A Less than B
More color than A Brighter than B Darker than A However, A is the isolated soybean protein of Example 1, and B is the isolated soybean protein of Comparative Example 1.

Application example 2 20% by weight of water was added to the defatted cotyledons obtained in the same manner as in application example 1, and using an experimental twin-screw extruder, the screw rotation speed was 5.
7OR, P, M, , die at barrel temperature 170℃
(5 mm φ) to obtain a textured protein with excellent fibrous structure.

Next, the defatted soybean used in Comparative Example 1 was treated in the same manner to obtain a textured protein with an excellent fibrous structure.

Each of the obtained textured proteins was rehydrated in hot water, drained, and then tested for flavor etc. by a panel of 10 people. The results are shown in Table-3.

Table-3 A B Astringency Less than B Bitterness More than A B
Less More astringent than A Less than B
Color more than A Brighter than IB Darker than A However, A is the textured protein of defatted soybean cotyledons, and B is the textured protein of defatted soybean.

(Effects) As detailed above, the present invention makes it possible to obtain soybean cotyledons with improved flavor and color tone and high NSI at a high yield. Furthermore, isolated soy protein,
Soybean cotyledons, which are excellent as raw materials for polysaccharides, oligosaccharides, soybean milk, and protein foods such as textured or fibrous, can be used to (a) easily split soybeans in half and peel them; (C1) This method enables the dehulling and hypocotyl removal method that facilitates the separation of the hypocotyl and cotyledons.In general, soybean dehulling is effective by aging the soybean, but the present invention uses a separate aging method. There is no need to do this.

As explained above, the present invention greatly contributes to the development of industry.

Claims (4)

[Claims] (1) Adjust the moisture content of soybeans to 12% or less, heat and dry the soybeans to a temperature of 70 to 80°C, and combine the steps of splitting them into two and peeling the split soybeans. A soybean processing method characterized by obtaining soybean cotyledons. (2) The soybean according to claim (1), in which the soybean is dried so that the soybean is split into two at a temperature of 70 to 80°C is passed through a grinder with a grindstone spacing wider than the soybean grain size. Processing method. (3) The soybean processing method according to claim (1) or (2), in which the soybean is peeled by cooling the split soybean to 30° C. or lower and then peeling the soybean using a peeling means. (4) The soybean processing method according to claim (1), in which the unhulled soybean that has been split into two and sieved is split into two again.