JP2006191860A - Method for producing soymilk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing soymilk to stably produce the soymilk for a long period of time by reducing scaling when subjecting soymilk and a product obtained by using soymilk to indirect heating. <P>SOLUTION: The method for producing soymilk comprises controlling soaking temperature and settling volume so as to reduce scaling during heat sterilization of the soymilk and stably produce the soymilk. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing soymilk and a method for preventing scaling when heat-treating soymilk or soymilk products.

  In recent years, the effect of soy protein to lower cholesterol has been clarified, and accordingly, interest in traditional soy milk, tofu, yuba, prepared soy milk, soy milk drinks and other various soy milk products has rapidly increased. The standards for soy milk, prepared soy milk, and soy milk drinks are determined by Japanese Agricultural Standards (Non-Patent Document 1).

  At the same time, soybean milk with improved flavor and texture has been developed in recent years. For example, Patent Document 1 discloses a method for improving soymilk odor and obtaining a soymilk with a clean texture. In addition, soy milk, soy milk drinks, and other various soy milk products that are made easier to drink by adding sweetness, flavor, cocoa, coffee, malt, fruit juice, etc. are also increasing.

However, in the conventional soymilk manufacturing method, if a plate-type sterilizer or tubular sterilizer, which is an indirect heat sterilizer, is used in the heat sterilization process when producing soymilk products such as beverages using soymilk, The phenomenon that agglomerates adhere to the inside of the pipe increases), which causes burning in the pipe and a decrease in heating efficiency, making it difficult to operate continuously for a long time.
For this reason, generally, a plurality of similar sterilization lines are prepared and sequentially switched while cleaning the inside of the pipe, so that the work efficiency is low and the cost is high. In particular, soy milk products with a soy solid content of 8% or more often have a significant deterioration in production efficiency due to frequent switching of the sterilization line, which is difficult to manufacture.
In addition, even when direct heat sterilization such as direct steam injection, which is said to have relatively little scaling, is used, stable operation for a long time is difficult.

(References)
December 19, 2000 Ministry of Agriculture, Forestry and Fisheries Notification No. 1684 Japanese Patent No. 3440749

  The object of the present invention is to prevent scaling that occurs during the heat treatment of soymilk and soymilk products without causing the above-mentioned problems, and can stably carry out continuous operation for a long time, and the quality of soymilk is also stable. It is providing the manufacturing method of the soymilk which can be made to do.

  As a result of intensive studies in view of the above problems, the present inventors have combined the combination of maintaining the soaking temperature of soybean at a certain temperature or more and reducing okara residue in soy milk as much as possible, and The knowledge which can solve the said subject was acquired by combining maintaining the temperature at the time of wet-grinding more than fixed temperature.

From the knowledge obtained above, the present invention is as described below,
1. In the soymilk manufacturing process in which soybean is soaked and then wet pulverized, and the resulting slurry is separated into soymilk and okara, the soybean soaking process is maintained at 80 ° C. or higher, and the obtained soymilk is kept at 1400 G for 10 minutes A method for producing soymilk, characterized in that the okara is separated until the amount of sediment upon centrifugation is 1.0 vol% or less of the soymilk,
2. The temperature during wet pulverization is maintained at 50 ° C. or higher. Described manufacturing method,
3. 1 above. A method for producing a soymilk product, comprising combining the soymilk obtained by the production method described above and performing a heat treatment,
4). 1 above. A method for preventing scaling when heat-treating soymilk, characterized by using the production method described above,
5. 1 above. A method for preventing scaling when heat-treating soymilk products, comprising blending soymilk obtained by the production method described above,
Is to provide.

  The present invention controls the soaking temperature of soybeans and the amount of precipitate of soy milk to significantly reduce the amount of scaling that occurs during heat sterilization, particularly when heated by an indirect sterilizer, that could not be resolved with conventional soy milk. It is possible to prevent the occurrence. Thereby, a heating process can be stably performed by continuous operation for a long time, and the quality of soymilk can also be stabilized.

According to the present invention, in the soymilk production process, the soybean soaking step is maintained at 80 ° C. or higher, and the amount of precipitate (spitz amount) obtained when the obtained soymilk is centrifuged at 1400 G for 10 minutes is 1. A method for producing soymilk characterized by separating okara until it becomes 0% by volume or less, and a method for preventing scaling when heat treating a soymilk product.
The present invention is described in detail below.

(Raw soybean)
The soybean milk of the present invention is suitably made from soybean seeds such as white soybean, yellow soybean, green soybean and black soybean. In order to remove the miscellaneous taste, soy-dehulled soybean with the seed coat and hypocotyl removed in advance is suitable.

(Immersion process)
In order to obtain the soymilk of the present invention, soybeans are first immersed in water and absorbed. The temperature of the water to immerse shall be 80 degreeC or more, and 80-95 degreeC is desirable. If the immersion temperature is too low, it is difficult to prevent the occurrence of scaling in the heating process even if the solid content of okara is sufficiently separated. On the other hand, if the immersion temperature is too high, the extraction rate of soy milk tends to decrease and the yield tends to decrease.
The soaking time that is sufficient to prevent scaling varies depending on the soaking temperature, and may be set while adjusting as appropriate. As a guideline, soaking at 80 ° C. is preferably 15 minutes or longer, preferably 25 minutes or longer. The immersion time can be shortened.
Since soybeans absorb almost the same weight of water, the amount of immersion water needs to be twice or more, and usually 2 to 10 times the amount of immersion water is used. Moreover, in order to improve the water absorption of soybean or to improve the flavor of soy milk, a pH adjusting agent such as sodium bicarbonate can be appropriately added to the immersion water.

(Wet grinding process)
Next, the soaked soybean is used as it is, or the soaking water is discarded and fresh water, preferably hot water is added, and the wet grinding process is started.
For the pulverization, a wet pulverizer can be used to obtain a pulverized suspension (hereinafter referred to as “slurry”). As the wet pulverizer, a known pulverizer such as a grinder, a colloid mill, or a rotating blade type shearing force can be used.
In particular, a grinding-type grinding device improves the extraction rate of soymilk solids, and as described in Patent Document 1, a grinding device that applies a rotating blade type shearing force, such as “COMITROL” (manufactured by URSCHEL), etc. Is preferred.
In the present invention, even if the pulverization temperature is less than 50 ° C., it is possible to sufficiently suppress the occurrence of scaling by high temperature immersion, but the scaling is further performed in the piping of the heating device for a longer time. When it is desired to obtain soy milk that is unlikely to be produced, it is preferable to perform the wet pulverization step at a temperature of 50 ° C. or more together with the soybean dipping step. Furthermore, 70 degreeC or more is more preferable, and 80 degreeC or more which is the same as immersion temperature is especially preferable. As a result, a substance that becomes a nucleus that causes scaling during heating can be further thermally denatured and removed.
If necessary, the slurry obtained by pulverization can be heated and held in the above temperature range for a predetermined time (for example, 30 seconds to 1 hour) to enhance the effect of suppressing the occurrence of scaling.
Furthermore, the extraction rate of soymilk solids can be further improved by homogenizing the slurry with a device that applies a frictional shearing force such as a homogenizer and making it into fine particles. In this case, if this process is also maintained in the above temperature range, the effect of suppressing the occurrence of scaling can be further enhanced.

(Okara separation process)
Next, the insoluble residue corresponding to okara is removed from the slurry by solid-liquid separation to obtain soy milk. In the present invention, it is more preferable to keep this separation step in the above temperature range, since it is possible to obtain soy milk that hardly causes scaling.
In the method of solid-liquid separation in the present invention, the amount of precipitate (hereinafter referred to as “spitz amount”) when the obtained soymilk is centrifuged at 1400 G for 10 minutes is 1.0 vol% or less of soymilk, that is, 100 ml of soymilk. It is important to use a method that separates until 1.0 ml or less. If the amount of Spitz exceeds this range, no matter how much soy milk is produced in the high temperature range as described above, it becomes easy to cause scaling in the piping of the heating device in the heat sterilization process, making it difficult to operate the heating device continuously and producing efficiency. Will be bad.
In order to make the amount of Spitz of soy milk within the above range, for example, a centrifuge is preferably used. Since the insoluble residue cannot be sufficiently removed by a method such as squeezing filtration, the amount of Spitz exceeds the upper limit, and scaling is likely to occur during heating. Any of a decanter type, a disk type, etc. may be used for the centrifuge. In order to remove the insoluble residue to a higher degree, it is preferable to combine these centrifuges. The operating conditions of the centrifuge can appropriately set the flow rate, centrifugal force, and centrifugal time so that the amount of Spitz of soy milk falls within the above range.

(Soybean solid content of soy milk)
The solid content (soybean solid content) of the soy milk obtained as described above is 7 to 15% by weight, preferably 8 to 14% by weight, more preferably 9 to 12% by weight when converted to soy milk. Is appropriate. This is because if the soy solid content is less than 8% by weight, it is difficult to call it soymilk in terms of specifications, and it is difficult to blend it as a raw material for soymilk products.

(Heat treatment)
Next, although this soymilk is processed at a high temperature of 80 ° C. or higher during the production process, since the heat-resistant bacteria in soybean do not die at such a temperature, when the above-mentioned soymilk is distributed as a raw material for soymilk products, it remains as it is. It is preferable to distribute it refrigerated or frozen, or distribute it at room temperature or lower after heat sterilization in a heat treatment apparatus. As the heat treatment apparatus, any of an indirect heating apparatus such as a plate type heat exchange apparatus and a scraping type heat exchange apparatus, or a direct heating apparatus can be used. Moreover, although it is different from the UHT apparatus, heat treatment can also be performed by a retort apparatus. The occurrence of scaling during the heat treatment is effectively prevented in the case of the soy milk of the present invention, but in general, the use of a direct heating device is preferred because the occurrence of scaling is reduced. In particular, a steam-blowing direct heating device is more preferable for preventing scaling during production of soy milk products. This is because the soy protein can be further heat-denatured because the high-temperature and high-pressure steam and soy milk are in direct contact with each other, and the shearing force is generated by the reduced pressure when returning to normal pressure, and the solid particles in the soy milk are further refined. It is to be done.
The soymilk antiscaling effect of the present invention is first demonstrated when heat treatment is performed to distribute the soymilk as raw material soymilk. That is, when sterilizing heat-resistant bacteria in soy milk, severer heating conditions are required compared to dairy products such as milk, and at least the F value is equivalent to 4 (min), preferably 6 (min) or more. The treatment is preferably performed, but the more severe the heating conditions are, the more easily scaling occurs in the piping of the heating apparatus. Therefore, the scaling prevention effect by using the manufacturing method of the present invention is extremely beneficial. .
In order to satisfy the above F value condition, the heating temperature is suitably 120 to 160 ° C, preferably 135 to 160 ° C, more preferably 140 to 150 ° C. Is suitable. If it is lower than 120 ° C., it is difficult to sterilize heat-resistant bacteria in soybean, or it takes a long time for sterilization. Moreover, when it exceeds 160 degreeC, deterioration of a flavor etc. will arise easily. The heating time for sterilization may be set so that the F value is 4 or more in the above temperature range, but it is usually 2 seconds to 30 seconds, preferably 4 seconds to 10 seconds. If it is shorter than 2 seconds, sterilization is not sufficient, and if it exceeds 30 seconds, problems such as deterioration of flavor, scorching, and coloring may occur.

(Manufacture of various soy milk products)
Like the soymilk obtained by the usual production method, this soymilk can be blended as a production raw material to produce various soymilk products and tofu products. For example, prepared soy milk, soy milk drink, soft drink, lactic acid fermented soy milk, pudding, soup, jelly, frozen confectionery, baked confectionery, Japanese confectionery, snack, bread, cake, yogurt, cheese, cream, filling, chocolate, spread, mayonnaise, sauce, fry It can mix | blend with foodstuffs, fishery paste products, livestock meat products, etc., and is not limited to this illustration.
In the production of various soymilk products, in addition to this soymilk, food raw materials (fruit juice, pulp, vegetables, sugars, fats and oils, dairy products, flours, cacao trout, seafood, etc.) and food additives (minerals, Vitamins, thickening stabilizers, emulsifiers, acidulants, fragrances, etc.) can be used as appropriate.

Secondly, the anti-scaling effect of the present invention is greatly exhibited during the heat treatment during the production of the soy milk product.
In the case of normal soymilk products, scales (insoluble solid matter deposits) are generated in the heating device when heat-treated, and scorching occurs during continuous operation for a long time, and they grow to increase the heating efficiency. It gets worse and eventually the line is blocked. This tendency is remarkable in an indirect heating apparatus such as a plate type that is widely used in production lines for beverages. On the other hand, in the case of genuine soymilk, scaling does not easily occur even if the same processing is performed. Therefore, continuous operation with a long operation time is possible.
Therefore, among the above-mentioned soy milk products, liquid soy milk products (prepared soy milk, soy milk drinks, soft drinks, lactic acid fermented soy milk, soup, sauce, cream) and solid soy milk products that are heat-sterilized, and intermediate soy products are liquid. It is effective in the production of foods (pudding, jelly, frozen dessert, yogurt, filling, chocolate, spread, mayonnaise, etc.).
In addition, adding alkaline earth metal ions that are highly reactive with proteins such as calcium as a nutritional enhancer to soy milk products promotes protein aggregation, further exacerbating scaling problems during heat sterilization. Since the soymilk of the invention has low reactivity with calcium, the occurrence of scaling can be effectively suppressed. Therefore, the use for soy milk products to which alkaline earth metal ions are added is particularly effective.

  In the production of the soy milk product using the soy milk of the present invention, the soy milk may be purchased as a raw soy milk to produce various soy milk products, or the soy milk of the present invention may be produced during the process of producing the various soy milk products. The manufacturing process may be included, and in any case, various soymilk products can be efficiently manufactured by the effect of preventing the occurrence of scaling.

  Although the Example of the soymilk of this invention is described below, it cannot be overemphasized that the technical idea of this invention is not limited by this description. In the following description, “%” and “parts” refer to weight units unless otherwise specified.

<Example 1>
10 parts of water is added to 1 part of molting and dehiscence axis soybeans, and then immersed in water at 85 ° C. for 30 minutes, water absorption is doubled and 1 part of molting and dehiking axis soybeans (water content 40-55%) What added 3 parts of hot water (90 degreeC) was wet-ground with COMITROL (made by URSCHEL), the obtained slurry was supplied to the homogenizer (made by APV), and it homogenized at 15 MPa. The homogenized slurry was supplied to a centrifuge (3000 G, 5 minutes) to separate okara, and soymilk of the present invention was obtained. The temperatures in the dipping, wet pulverization, homogenization, and separation steps were all maintained at 80 ° C. or higher. The obtained soymilk has a solid content of 9.0%, protein of 4.5% and pH of 6.7, and when this soymilk is placed in a 10 ml Spitz tube and centrifuged at 1400 G for 10 minutes, the amount of precipitation (spitz amount) is The amount was 0.07 ml per 10 ml of soy milk, that is, 0.7% by volume of soy milk.

<Comparative Example 1>
Example 1 Except that the molting and dehiking shaft soybeans were soaked at 20 ° C for 240 minutes, and that the temperatures in the soaking, wet grinding, homogenization, and separation steps were all kept at 20 ° C ± 3 ° C. Soy milk. The obtained soymilk had a solid content of 9.0% by weight, a protein of 4.5% by weight and a pH of 6.7, and the amount of spitz was 0.7% by volume of the soymilk.

<Example 2- (a), 2- (b), 2- (c)> (Examination of Okara Separation Conditions)
In the same manner as in Example 1, when separating okara from the homogenized slurry by a centrifuge, only the centrifugal force of the centrifuge is changed to 2500G (a), 2000G (b), 1500G (c), Soy milk with different amounts of Spitz was obtained. All of the obtained raw material soymilk were adjusted to a solid content of 9.0% by weight. The protein content was 4.5% by weight and the pH was 6.7. Further, the amount of spitz per volume of soymilk was 1.0% by volume in Example 2- (a), 1.5% by volume in Example 2- (b), and 2.0% by volume in Example 2- (c).

<Example 3- (a), 3- (b), 3- (c)>
Water (20 ° C- (a), 40 ° C- (b), 60 ° C- (c)) was added to the soaked and dehulled soybeans that had absorbed water after immersion at 85 ° C, respectively, and the water temperature was adjusted to ± 3 ° C. The soymilk which performed wet grinding, homogenization, and isolation | separation in the low temperature to intermediate temperature range was obtained using the manufacturing method similar to Example 1 except performing wet grinding, homogenization, and isolation | separation, hold | maintaining. All of the obtained three types of soymilk had a solid content of 9.0% by weight, a protein of 4.5% by weight, a pH of 6.7, and a spitz content of 0.7% by volume of the soymilk.

<Comparative Example 2- (a), 2- (b), 2- (c)>
Except for changing the immersion temperature to three temperatures of 20 ° C- (a), 40 ° C- (b), and 60 ° C- (c), the same manufacturing method as in Example 1 was used. Soy milk was obtained. In addition, the temperature in the wet pulverization, homogenization, and separation processes after the dipping process was maintained at 80 ° C. or higher as in Example 1. All of the obtained three types of soymilk had a solid content of 9.0% by weight, a protein of 4.5% by weight, a pH of 6.7, and a spitz content of 0.7% by volume of the soymilk.

<Example 4>
Soy milk was obtained in the same manner as in Example 1 except that the immersion time was 20 minutes. The obtained soymilk had a solid content of 9.0% by weight, a protein of 4.5% by weight and a pH of 6.7, and the amount of spitz was 0.7% by volume of the soymilk.

(Test example)
Each of the soy milk obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was preheated to 60 ° C., 110 ° C. at the first heating with a plate type UHT heating device (manufactured by Powerpoint), and then at the second heating. The temperature was raised to 140 ° C. and held for 30 seconds with a holding tube. The flow rate was 20 L / hour. The area of the heating plate was 0.0095 m ² .
Judgment of the state of scaling confirmed the presence or absence of the rise of the heat source temperature and back pressure of the plate type UHT heating device, and the amount of solids adhering to the plate when the plate was disassembled after the heating. The results are shown in Table 1.
In general, when scaling occurs in the heating device, the heat conductivity from the heat source is deteriorated, and accordingly, the temperature of the soy milk is maintained at the set sterilization temperature, and the heat source temperature is increased. If soy milk becomes difficult to flow through the line due to scaling, the back pressure increases to keep the flow rate constant. Therefore, the increase in the heat source temperature and the back pressure can be used as an index for occurrence of scaling.

(Table 1)

  Although the soy milk of Example 1 and Example 2- (a) was allowed to flow continuously for 5 hours, the heat source temperature and the back pressure hardly increased, and the heat treatment could be performed without any problems. There was almost no scaling when disassembling the plate, and the heating device could be operated stably for a long time.

  In the soymilk of Example 2- (b) and (c), the heat source temperature and the back pressure were increased from 40 minutes after starting heating and after 70 minutes, respectively. When the operation was interrupted at this point and the device was disassembled, thin scaling was observed on the entire plate, and it was determined that continuous operation was difficult.

  The soy milk of Example 3- (a) to (c) was found to have increased heat source temperature and back pressure from 100 minutes after the start of heating because of the lower temperature during wet grinding compared to Example 1, and scaling also occurred. . However, as compared with Comparative Example 1, the time until the heat source temperature and the back pressure rose clearly was extended, and scaling was suppressed. And the higher the temperature during wet grinding, the higher the anti-scaling effect.

  In both the soy milks of Comparative Examples 1 and 2, the heat source temperature and the back pressure were increased from 60 minutes after the start of heating. When the operation was interrupted at this point and the device was disassembled, thin scaling was observed on the entire plate, and it was determined that continuous operation was difficult. By the way, in Comparative Example 1, the heat treatment was continued even after the heat source temperature and the back pressure were increased, but the operation was stopped because the flow rate decreased after 2 hours from start and scorching was mixed in the treatment liquid. . When the plate after disassembling the apparatus was observed, scaling was observed on the entire surface, and the line was on the verge of closing.

  The soymilk of Example 4 was found to have increased heat source temperature and back pressure from 120 minutes after the start of heating, probably because the soaking time was shortened. When the operation was interrupted at this point and the device was disassembled, thin scaling was observed on the entire plate, and it was determined that continuous operation was difficult. However, compared with the comparative example 1, the time which can be continuously operated was extended and the suppression effect of scaling was seen.

<Example 5> Examination 1 with prepared soymilk
Using the soy milk obtained in Example 1, prepared soy milk was prepared as follows.
Add 70 parts of soy milk, 1.5 parts of sugar, 0.3 part of calcium lactate, 0.1 part of salt, 0.1 part of glycerin fatty acid ester and 18 parts of water, mix at 60 ° C, homogenize at 15 MPa, and then plate-type UHT heating device (Powerpoint) Manufactured), the temperature was raised to 110 ° C. by the first heating and then to 140 ° C. by the second heating, and was held in the holding tube for 30 seconds. The flow rate was 20 L / hour. The area of the heating plate was 0.0095 m ² . The determination of the scaling state was confirmed in the same manner as in the test example.

<Comparative Example 3> Study 2 with prepared soymilk
Prepared soymilk was prepared in the same manner as in Example 5 using the soymilk obtained in Comparative Example 1. The determination of the scaling state was confirmed in the same manner as in the test example.

<Example 6> Study 3 with prepared soymilk
Using the soymilk obtained in Example 3- (c), a prepared soymilk was prepared in the same manner as in Example 5. The determination of the scaling state was confirmed in the same manner as in the test example.
The scaling evaluation results in Examples 5 and 6 and Comparative Example 3 are shown in Table 2.

(Table 2)

In the prepared soymilk of Example 5, the heat source temperature and the back pressure began to increase slightly after 300 minutes from the start of heating. However, the subsequent increase was mild, and even if treated continuously for 5 hours, Only thin scaling was observed. Since this prepared soymilk is supplemented with calcium ions, it will normally cause significant aggregation with proteins due to heat treatment, which should encourage scaling, but despite this concern, continuous heat treatment can be performed with little problem. It was possible.
In the prepared soy milk of Comparative Example 3, the temperature of the heat source and the back pressure increased from about 40 minutes after the start of heating, the flow rate decreased in 70 minutes, and scorching contamination was recognized in the treatment liquid. When the plate was suddenly stopped and the device was disassembled, the entire surface was tightly scaled and was on the verge of closing.
Although the time which the preparation soymilk of Example 6 could also be heated continuously was shorter than Example 5, it became longer than the comparative example 3, and the scaling inhibitory effect was seen.

<Example 7> Study 4 with prepared soymilk
Prepared soymilk was prepared in the same manner as in Example 5 using soymilk obtained by treating the soymilk obtained in Example 1 with a steam blowing direct heating device at a temperature of 144 ° C. for 4 seconds.
In the prepared soymilk of Example 7, even after 300 minutes from the start of heating, the temperature of the heat source and the back pressure were not increased, and the antiscaling effect was further confirmed as compared with the prepared soymilk of Example 5. Even after 5 hours of continuous treatment, almost no scaling was observed in the decomposed plate.

In conventional production of soymilk and soymilk products, scaling generated in a heating device such as a plate-type heat sterilizer has been an obstacle to continuous operation for a long time. By using the soymilk manufacturing method of the present invention, the occurrence of scaling during the heat treatment is remarkably prevented, so that it is interrupted in the middle of production and the apparatus must be washed continuously and stably over time. Soymilk and soymilk products containing it can be manufactured. Therefore, it can greatly contribute to the development of the soy milk industry.

Claims (5)

In the soymilk manufacturing process in which soybean is soaked and then wet pulverized, and the resulting slurry is separated into soymilk and okara, the soybean soaking process is maintained at 80 ° C. or higher, and the obtained soymilk is kept at 1400 G for 10 minutes A method for producing soymilk, characterized in that okara is separated until the amount of sediment upon centrifugation is 1.0 vol% or less of soymilk. The production method according to claim 1, wherein the temperature during wet grinding is maintained at 50 ° C. or higher. A method for producing a soymilk product, wherein the soymilk obtained by the production method according to claim 1 is blended and heat-treated. A method for preventing scaling when heat-treating soymilk, wherein the production method according to claim 1 is used. A method for preventing scaling when heat-treating a soymilk product, comprising blending soymilk obtained by the production method according to claim 1.