CN115568553A

CN115568553A - Water-saving high-protein soymilk and production method thereof

Info

Publication number: CN115568553A
Application number: CN202211221127.7A
Authority: CN
Inventors: 毛方华; 杨仁珠; 罗钦; 杨永杰
Original assignee: Sanming Yangchen Foodstuff Co ltd; Institute of Agricultural Engineering Technology of Fujian Academy of Agricultural Sciences
Current assignee: Sanming Yangchen Foodstuff Co ltd; Institute of Agricultural Engineering Technology of Fujian Academy of Agricultural Sciences
Priority date: 2022-10-08
Filing date: 2022-10-08
Publication date: 2023-01-06

Abstract

The invention relates to the technical field of soymilk processing, in particular to water-saving high-protein soymilk and a production method thereof. Peeled soybeans are used as initial raw materials, soaking is carried out for 0.8-1.2 h by using soaking liquid with the temperature of 70-90 ℃ and the pH value of 8.5-9.0, and the soaking liquid comprises coarse grinding, primary fine grinding, secondary fine grinding, pulp boiling, emulsifying, homogenizing, high-level tank temporary storage, filling, sterilizing and warehousing, so that the beany flavor and the astringent flavor of the soybeans are removed, the dissolution rate of soybean protein is greatly improved, the protein dissolution rate of the soybean milk product is improved to more than 93%, the nutritional value and the additional value of the soybean milk product are improved, foams generated in the filled soybean milk are removed through special operations such as emulsifying, homogenizing and high-level filling, and the stable quality and long-term lasting quality guarantee of the soybean milk product are maintained.

Description

Water-saving high-protein soymilk and production method thereof

Technical Field

The invention relates to the technical field of soymilk processing, in particular to a water-saving high-protein soymilk and a production method thereof.

Background

Soybean is one of important food crops, has the history of cultivation for over five thousand years, is a crop rich in plant protein, the content of the protein in the soybean is about 40 percent, and about 80 to 90 percent of the protein can be dissolved in water. Soybeans are commonly used in the manufacture of various soy products, the extraction of soybean oil, the brewing of soy sauce, and the extraction of protein powder products.

The soymilk has high nutritional value as a common bean product, and is deeply loved by the consumers. The soybean has special beany flavor and bitter taste, which can affect the mouthfeel of the soybean beverage, and many bean beverage manufacturers generally mask the beany flavor of the soybean by adding the flavor generated by other flavor auxiliary preparations. However, since soybeans contain various proteases, and when other substances are added, unpleasant odor substances are still generated, and when the unpleasant odor substances become too much, they cannot be masked by other odors, and thus, it is still necessary to remove the beany flavor from soybeans themselves. In addition, the traditional soymilk production method causes low protein dissolution rate of the soybeans, and reduces the nutritional value and the market economic value of the soymilk product. The technology for improving the extraction rate of soybean protein in the production process of the soymilk is one of key nodes for restricting soymilk production enterprises.

The invention patent CN1052145C discloses a method for producing instant soybean powder, which comprises the steps of firstly, carrying out pretreatment such as screening, drying, breaking and peeling the soybean, cleaning and the like; wherein the drying is to dry the soybeans at the temperature of not higher than 100 ℃ by hot air until the water content is 6-7 percent, and then cool the soybeans by air to below 40 ℃; then soaking the bean segments which are peeled and cleaned by breaking the bean segments in water, blanching the soaked bean segments for 5 to 60 seconds at the temperature of between 80 and 85 ℃, quickly cooling the bean segments to be below 40 ℃, adding water to coarsely crush the bean segments into soybean milk, placing the soybean milk into a soybean milk cooking tank, adding ingredients to cook the soybean milk, boiling the soybean milk at the temperature of 100 ℃, and homogenizing the soybean milk; spray drying the homogenized soybean milk, wherein the air inlet temperature of a spray tower is 140-170 ℃, and the air outlet temperature is not higher than 90 ℃; collecting the spray product, sieving with 20 mesh sieve, cooling, and packaging to obtain the final product. The method considers that beany flavor and bitter taste in the bean powder product are removed, and centrifugal spray drying is adopted to improve the instant property and the quality guarantee period of the product, but a good solution is not provided for improving the soybean protein dissolution rate of the product, and negative effects caused by water conservation and wastewater discharge to the environment are not noticed in the manufacturing process.

The invention patent CN105394189B discloses a method for making healthy and nutritional soybean milk, which comprises the following steps: a first soaking step: removing soybean hulls from soybeans, soaking obtained soybean cotyledons and germs in water with the initial temperature of 60-70 ℃, and cooling to the ambient temperature within 10-120 minutes, wherein the ambient temperature is 15-30 ℃; a second soaking step: adding water, and soaking at normal temperature; pulping: keeping the mixture state of the materials, grinding the materials into thick liquid, filtering the residues, and sterilizing to obtain the required soybean milk. The preparation method adopts rapid cooling to improve astringency of embryo bud, reduce enzyme activity in soybean, and effectively improve protein swelling process. In order to better obtain a more effective swelling and water absorption process, the water absorption saturated state is reached more quickly, and the flavor of the soybean milk is improved. However, the temperature reduction control process of the preparation method is complicated and tedious, the preparation method is not easy to popularize, the soybean milk has good flavor but has a slightly inferior protein dissolution rate and mouthfeel, and the stability of the quality of the finished product and the long-term storage stability are worried.

Disclosure of Invention

Therefore, the water-saving high-protein soymilk and the production method thereof are needed to solve the problems that the soybean protein dissolution rate is low in soymilk production, the soymilk is easy to generate bubbles to cause unstable product quality, the soymilk is not resistant to transportation and storage, the production water consumption and the wastewater discharge amount are large to cause adverse effects on the environment and the like in the prior art.

In order to achieve the above object, in a first aspect, the present invention provides a method for producing water-saving high-protein soybean milk, comprising the steps of:

pre-treating, namely soaking peeled soybeans in pure water at 70-90 ℃, wherein the adding mass ratio of the peeled soybeans to the pure water is 1:7-10, adding edible alkali solution to adjust the pH value to 8.5-9.0, and soaking for 0.8-1.2 h to obtain a bean product to be ground;

coarse grinding, namely performing coarse grinding on the bean product to be ground by adopting colloid mill equipment to obtain bean dreg slurry mixed liquid;

performing primary fine grinding, namely performing primary fine grinding on the bean dreg slurry mixed solution, and then performing primary solid-liquid separation to obtain bean dregs and first slurry;

performing secondary fine grinding, namely adding pure water into the bean dregs for secondary fine grinding, and performing secondary solid-liquid separation to obtain waste bean dregs and second slurry;

placing the first slurry and the second slurry into a slurry boiling tank for boiling, and then carrying out third solid-liquid separation to obtain a soybean milk crude product;

preparing an emulsion: uniformly mixing a proper amount of stabilizer and white sugar, adding the mixture into a high-speed shearing emulsifying tank, adding a proper amount of coconut oil and salt, adding a pH regulator, and uniformly mixing to obtain the emulsion;

transferring the soymilk crude product and the emulsion to a preparation tank, flushing residual emulsion in the emulsion tank with a small amount of water, pouring the flushing liquid into the preparation tank, and fixing the volume; homogenizing for the first time to obtain primary soybean milk;

transferring the primary soybean milk product to a temporary storage tank for standing, and then carrying out secondary homogenization in a second homogenizer at 75 ℃ and under 60MPa to obtain the soybean milk to be filled;

transferring the soymilk to be filled to a high-level tank for temporary storage, performing fourth solid-liquid separation, filling, sterilizing and warehousing.

The invention adopts peeled soybeans as main raw materials, and aims to realize the deodorization of the soybean milk and improve the extraction rate of the soybean protein. The peeled soybeans can soften the cell walls of the soybeans by soaking in pure water at the temperature of 70-90 ℃, so that the production energy consumption and mechanical abrasion during grinding are reduced, and the dissolution rate of soybean protein can be obviously improved. The inventor finds out through mass production practice that the optimum material-water ratio is 1:7-10, can prevent the soybean protein dissolution rate from being reduced due to insufficient water addition under the condition of the ratio, can also prevent the soybean protein from losing with water along with the removal of bean dregs and the dissolution of the separation skin during the solid-liquid separation process caused by excessive water addition, aims to achieve the optimum extraction state of the soybean protein, can ensure that all soaking water is absorbed by peeled soybeans, and can fully soften soybean cells. In the production of the soymilk, the soaked water is not poured, and all the water is transferred to the soymilk product, so that the water resource is saved, and the pressure of the discharge of the soymilk production wastewater on the ecological environment is reduced.

The temperature of pure water for soaking has significant influence on the soybean protein, and the protein is easily denatured due to overhigh temperature; the protein dissolution is influenced by the excessively low temperature, and the protein extraction rate is reduced. The applicant repeatedly practices at 50-100 ℃, researches and develops the proper soaking temperature of 70-90 ℃, more preferably the soaking temperature of 80 ℃, and the dissolution rate of the soybean protein reaches the optimal value.

Although the greater the deviation of the pH of the aqueous soaking solution from the isoelectric point of the soy protein, the higher the dissolution rate of the soy protein, the higher the pH required for the first time poses other problems. If the pH value of the soaking water solution is too high, the soymilk is easy to darken and become dark after heating and sterilization, and the mouthfeel becomes astringent; of course, too low a pH of the aqueous soaking solution may cause precipitation of soy protein and delamination. Thus, the unsuitable pH of the aqueous soaking solution can seriously affect the quality of the soy milk product. Through a large number of experimental researches on a production line, the applicant obtains that the most suitable pH value of the soaking water solution is between 8.5 and 9.0, more preferably the pH value is 9.0, the soybean is soaked for inactivating enzyme, the dissolution rate of soybean protein can be ensured to be more than 93 percent, and the color and the taste of the soybean milk product can be ensured to be in the best state.

In order to achieve the highest dissolution rate of the soybean protein, the applicant also carries out deep research and analysis on the soybean soaking time, wherein the soaking time is 15 hours when the indoor temperature is below 10 ℃, the soaking time is 10 hours when the indoor temperature is between 10 and 20 ℃, the soaking time is 8 hours when the indoor temperature is between 20 and 26 ℃, and the soaking time is 6 hours when the indoor temperature is above 26 ℃. The corresponding soaking time is selected according to different water temperatures, so that the soybean protein can be prevented from being seriously dissolved due to insufficient water absorption of the soybeans, or the soybean protein can be prevented from being decomposed due to excessive soaking of the soybeans. After a large number of experiments and explorations, the optimal soaking time is 0.8-1.2 h when the soaking water temperature is 70-90 ℃, the pH value is 8.5-9.0, the adding mass ratio of the peeled soybeans to the pure water is 1:7-10.

The coarse grinding process is carried out by adopting colloid mill equipment, common crushing equipment can be adopted, colloid mill equipment with the power of 5.5kw is adopted in the invention, and the rotating speed is set to be 2990r/min.

The first fine grinding still adopts the same rotating speed as the coarse grinding process, but the power is greatly improved compared with the coarse grinding, and the mixed liquid of the bean dregs and the milk (without discharging any substance) obtained after the coarse grinding is subjected to the first fine grinding. After the primary fine grinding, the dissolution rate of the soybean protein is further improved compared with the coarse grinding. Then, the product after the first fine grinding is subjected to centrifugal separation to obtain the bean dregs and the first slurry.

And adding pure water into the bean dregs obtained by the primary fine grinding for secondary fine grinding, wherein most of protein in the soybeans is dissolved into a liquid phase by the primary fine grinding, and the purpose of covering water on the bean dregs for secondary fine grinding is to further dissolve the protein in the bean dregs into the liquid phase, so that the protein content and the nutritional value of the soybean milk product are improved. And filtering the product after the secondary fine grinding by using a centrifugal machine provided with a 120-mesh filter screen to obtain the waste bean dregs and the second slurry. It should be noted here that although the waste okara can be finely ground for the third time or more, the applicant found that the fine grinding after the third time has no obvious benefit for increasing the protein content of the soybean milk product, but the energy consumption and the operation process cost caused by the fine grinding for the third time or more are significantly increased, so that the mode of coarse grinding + first fine grinding + second fine grinding is adopted in the present invention, and the fine grinding operation for the second time after the fine grinding is not limited and excluded.

It should be noted that the pulp boiling step and the emulsion blending step are not in a sequential relationship and can be performed simultaneously. The boiled soybean milk and the emulsified liquid in the emulsifying tank enter the blending tank for constant volume, so that the stability of the soybean milk can be greatly enhanced, and if the stabilizer, the white sugar, the coconut oil, the salt, the pH regulator and the like are added into the boiled soybean milk in the blending tank for stirring for constant volume, large agglomerates or coagulum are easy to appear.

The high-level tank needs to pass through a 100 mesh security filter or a pipeline filter before being led to the filling inlet, so as to ensure that the filled soymilk has no impurities in the particles.

The method is different from the prior art, the peeled soybean is used as an initial raw material, soaking is carried out for 0.8-1.2 h by using a soaking solution with the temperature of 70-90 ℃ and the pH value of 8.5-9.0, and the steps of coarse grinding, primary fine grinding, secondary fine grinding, pulp boiling, emulsification, homogenization, temporary storage in an elevated tank, filling, sterilization and warehousing are sequentially carried out, so that the beany flavor and astringent flavor of the soybean are removed, the dissolution rate of the soybean protein is greatly improved, the protein dissolution rate of the soybean milk product is improved to more than 93 percent, the nutritional value and the added value of the soybean milk product are improved, the foams generated in the filled soybean milk are removed through special operations such as emulsification, homogenization, elevated filling and the like, and the stable quality and long-term and lasting quality guarantee of the soybean milk product are maintained.

Compared with the prior art, the invention has the great difference that the water consumption is low and almost no waste water is discharged. Therefore, only the second fine grinding step is water-covered fine grinding with pure water, except for soaking the peeled soybeans in pure water, blending the emulsion, adding a small amount of pure water, and washing. Preferably, the second fine grinding is carried out on the bean dregs and the pure water according to the mass ratio of (1-2) to (0.5-1.0). By this arrangement, the use amount of the peeled soybeans and the total use amount of the pure water can be maintained in the relationship of 1. More preferably, the second solid-liquid separation is centrifugation. The centrifugal method ensures that the solid-liquid separation of the waste bean dregs and the second slurry is realized with high efficiency.

In an exemplary embodiment of the invention, the soybean milk cooking tank is a steam soybean milk cooking tank at the temperature of 95-100 ℃, and the soybean milk cooking time is 10-20 min. And mixing the slurry after the fine grinding and the solid-liquid separation, pouring the mixture into a slurry boiling tank, and starting steam to heat the mixture at the heating temperature of 95-100 ℃. Preferably, when the temperature of the pulp in the pulp cooking tank reaches 97 ℃, the pulp is continuously boiled till no bubbles exist, and the steam-boiling-defoaming time is 10-20 min from the statistics result of time. In the concrete operation, the slurry surface can be seen by the air bubbles which are 1cm away from the liquid level of the slurry or the edge of the slurry boiling tank, and the defoaming is judged to be finished.

In an exemplary embodiment of the invention, the rough grinding and the first fine grinding are both performed at 80 to 90 ℃. The arrangement can further improve the protein dissolution rate of the soybean, the temperature can not be lower than 80 ℃, the activity of the lipoxidase is inactivated at the temperature below 80 ℃, and the fishy smell of the soybean milk can reappear.

The peeled soybean purchased in the market can be directly adopted, and the peeled soybean can also be self-made. In an exemplary embodiment of the present invention, the method of making the dehulled soybeans comprises the steps of: placing the soybeans in an oven at 85-88 ℃ for baking; cooling the heated and dried soybean to normal temperature within 30-40 min; and carrying out high-speed negative pressure peeling to obtain the peeled soybeans, wherein the peeling rate of the peeled soybeans is more than 95%. The soybeans are fully heated and quickly cooled, the skins and the cotyledons of the soybeans can be separated, and the peeling can be quickly realized by adopting a high-speed negative-pressure hot air mode, so that the fresh, clean and pollution-free peeled soybeans are obtained.

In an exemplary embodiment of the present invention, the third solid-liquid separation is mechanical filtration using a vibrating screen having a mesh size of 200 mesh. After two times of centrifugal solid-liquid separation before boiling, the bean dregs are treated almost and the quantity of dregs is little.

In an exemplary embodiment of the invention, the conditions of the first homogenization and the second homogenization are both 65-80 ℃ and 40-55 MPa. The soybean milk is extruded from the slit of the homogenizing valve under high pressure during homogenizing, and the particles such as fat globules and proteins are micronized under the combined action of shearing force, impact force and cavitation effect to form uniform dispersion liquid. Through twice homogenization, fat floating and protein precipitation can be fully prevented, and the soft taste, the glossiness and the stability of the soymilk are improved. If the homogenization condition exceeds the temperature of 80 ℃ and the pressure of 55mPa, firstly, the homogenizer is easy to damage, so that the shutdown maintenance of the production indirectly increases the production cost; secondly, too high a temperature can reduce the taste, gloss and stability.

In an exemplary embodiment of the invention, the step of formulating the emulsifier further adds one of a wheat flavor aid, an oat flavor aid, a fruity or a fresh flower flavor aid. In order to meet the increasingly complex consumption requirements, the water-saving high-protein soymilk production method is expanded to various products with higher nutrition and flavor added values, and the economic benefits of the production method and the production line can be improved.

In a preferred embodiment of the invention, the position of the outlet of the high-level tank is 18-23 cm higher than the position of the inlet of the filling step. The high-level tank for storing the soymilk to be filled is arranged at a high position, so that air bubbles in the soymilk before filling can be fully eliminated. More importantly, through continuous production practice exploration, when the position of the discharge port of the high-level tank is 18-23 cm higher than the position of the feed port in the filling step, unpowered filling can be generated through natural gravity difference, filling energy loss can be saved, no bubble is generated at the top of the filled soymilk, the stable quality of the soymilk is fully ensured, and the storage and transportation life and the quality guarantee period of the soymilk are prolonged.

In a second aspect of the invention, a water-saving high protein soymilk is provided, which is produced by the production method of the first aspect of the invention.

Drawings

FIG. 1 is a schematic view of the process flow of a water-saving high protein soy milk production method embodied in the present invention.

Detailed Description

To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or related to other embodiments specifically defined. In principle, in the present application, the technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution as long as there is no technical contradiction or conflict.

Unless defined otherwise, technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the use of relational terms herein is intended only to describe particular embodiments and is not intended to limit the present application.

In the description of the present application, the term "and/or" is a expression for describing a logical relationship between objects, indicating that three relationships may exist, for example, a and/or B, indicating that: there are three cases of A, B, and both A and B. In addition, the character "/" herein generally indicates that the former and latter associated objects are in a logical relationship of "or".

In this application, terms such as "first" and "second" are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Without further limitation, in this application, the use of "including," "comprising," "having," or other similar expressions in phrases and expressions of "including," "comprising," or "having," is intended to cover a non-exclusive inclusion, and such expressions do not exclude the presence of additional elements in a process, method, or article that includes the recited elements, such that a process, method, or article that includes a list of elements may include not only those elements but also other elements not expressly listed or inherent to such process, method, or article.

As is understood in the examination of the guidelines, the terms "greater than", "less than", "more than" and the like in this application are to be understood as excluding the number; the expressions "above", "below", "within" and the like are understood to include the present numbers. In addition, in the description of the embodiments of the present application, "a plurality" means two or more (including two), and expressions related to "a plurality" similar thereto are also understood, for example, "a plurality of groups", "a plurality of times", and the like, unless specifically defined otherwise.

In the description of the embodiments of the present application, spatially relative expressions such as "central," "longitudinal," "lateral," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used, and the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the specific embodiments or drawings and are only for convenience of describing the specific embodiments of the present application or for the convenience of the reader, and do not indicate or imply that the device or component in question must have a specific position, a specific orientation, or be constructed or operated in a specific orientation and therefore should not be construed as limiting the embodiments of the present application.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," "secured," and "disposed" used in the description of the embodiments of the present application are to be construed broadly. For example, the connection can be a fixed connection, a detachable connection, or an integrated arrangement; it can be a mechanical connection, an electrical connection, or a communication connection; they may be directly connected or indirectly connected through an intermediate; which may be communication within two elements or an interaction of two elements. Specific meanings of the above terms in the embodiments of the present application can be understood by those skilled in the art to which the present application belongs according to specific situations.

The applicant finds that the soymilk is suitable for all ages as a beverage due to low protein content in the long-term soymilk production and market research, so that the consumers keep a careful attitude on the nutritional value of the soymilk, and the market value and the economic benefit of the soymilk are indirectly influenced. The method improves the protein dissolution rate of the soybean in the process of producing the soymilk and byproducts thereof, and is a key technology for realizing transformation and upgrading of the soymilk industry. Moreover, as a green healthy drink, how to prolong the shelf life and the quality stability as much as possible under the condition of avoiding adding additives such as preservatives and the like is an important ring for realizing ecological, green and scientific upgrading of the traditional parent soymilk drink. Therefore, a great deal of research and development cost is invested in the aspects of continuous production practice adjustment, process debugging, device allocation and the like. The applicant strives for controllable production cost and tries to achieve the unification of water-saving high-protein soymilk production and zero wastewater discharge by accurately controlling the material-water ratio in the production process.

The soybean used in the present invention is not particularly limited, and examples thereof include, but are not limited to, domestic or imported transgenic or non-transgenic soybean, and of course, green soybean, black soybean, green heart soybean, red bean, and the like can be used.

Example 1A water-saving high protein soymilk and method for producing the same

The production method of the water-saving high-protein soymilk provided by the invention comprises the following steps:

pretreatment, namely soaking peeled soybeans purchased from the market in pure water at the temperature of 80 ℃, wherein the adding mass ratio of the peeled soybeans to the pure water is 1 ₃ Regulating the pH value of the solution to 8.5, and soaking for 1h to obtain the bean product to be ground. The pretreatment can sufficiently eliminate lipoxygenase and prevent the soybean milk from generating peculiar smell.

And (4) coarse grinding, namely performing coarse grinding on the bean product to be ground at about 80 ℃ by adopting colloid mill equipment, wherein the coarse grinding time is 12min, so as to obtain the bean dreg slurry mixed solution. The coarse grinding equipment is a colloid mill produced by gallery general machine manufacturing factory, ltd, the power is 5.5kw, and the rotating speed is 2990r/min. After coarse grinding, about 70% of the protein in the soybeans is dissolved out.

And (3) performing primary fine grinding on the mixed solution of the bean dregs and the soybean milk by a fine grinding machine at the temperature of about 80 ℃, wherein the primary fine grinding time is 10min, and the primary fine grinding time can be properly prolonged according to the processing capacity and the actual throughput of the machine. Then centrifugal desludging is carried out to obtain the bean dregs and the first slurry. The power of the fine mill used for the first fine milling is 18.5kw, and the rotating speed is 2990r/min. After the first fine grinding, about 85% of the protein in the soybean is dissolved out.

And (3) fine grinding for the second time: and adding pure water into the bean dregs, and performing secondary fine grinding at the temperature of about 80 ℃ by using a fine grinding machine, wherein the material-water ratio of the bean dregs to the pure water is 1.5, the fine grinding machine used for the secondary fine grinding is the same as the fine grinding machine used for the primary fine grinding, but the volume and the horsepower of the machine are relatively smaller, and the time for the secondary fine grinding is 13min. And then centrifugal deslagging is carried out to obtain waste bean dregs and second slurry. After the second fine grinding, about 90% of the total protein in the soybeans was dissolved out.

And mixing the first slurry and the second slurry, placing the mixture into a slurry boiling tank for boiling, wherein the slurry boiling tank takes steam as a heating source, the boiling temperature is set to be 95-100 ℃, when the temperature of the slurry is 97 ℃, the mixture is continuously boiled till no bubbles exist, namely the bubbles are more than 1cm away from the liquid level of the slurry or the liquid level of the slurry can be seen at the edge of the slurry boiling tank, judging that the defoaming is finished, boiling the slurry for 10min, and taking 20min for the total of steam boiling and defoaming. Then, the soybean milk is filtered by a vibrating screen at 1500rpm, and the aperture of a sieve pore is 200 meshes, so that the soybean milk crude product is obtained.

Transferring the soybean milk crude product to a blending tank, and adding common edible regulation sucrose fatty acid ester purchased from the market into the soybean milk crude product, wherein the addition amount of the sucrose fatty acid ester is the quality of the soybean milk crude product. Detecting the pH value and temperature of the mixed liquid in the blending tank, wherein the pH value is 7.3, the temperature is 70 ℃, observing a level meter Rong Yewei (the allowable error is +/-mm, and the record table needs to be annotated) when the mixed slurry in the blending tank is not fluctuated, stirring for 5min after the volume is completely fixed, adding auxiliary edible spice, and stirring for 5min.

And (3) placing the mixed slurry obtained by blending the blending tank into a first homogenizer for first homogenization to obtain a primary soybean milk product. And transferring the primary soybean milk product to a temporary storage tank for standing, and then carrying out secondary homogenization in a secondary homogenizer at 75 ℃ and 55MPa to obtain the soybean milk to be filled. The soybean protein is subjected to the treatment technical effects of shearing, turbulence and the like in the homogenizing process, the non-covalent bonds between soybean protein molecules are broken under the action of temperature rise, inter-molecular or intra-molecular heavy aggregation is generated, the particle size is reduced, the specific surface area is increased, the intermolecular hydrophobic effect and electrostatic attraction effect are destroyed, the contact area of the protein and water is increased, the dissolution rate of the soybean protein is further increased, the taste and the stability of the soybean milk can be improved, and the shelf life of the soybean milk product is remarkably prolonged to about 13 months. In the technical research and development process, according to the actual conditions of production equipment, considering cost-saving production efficiency of enterprises, low-pressure homogenization treatment is innovatively adopted, a secondary low-pressure homogenization process is set, the pressure is set to be 40-55 MPa, and the temperature is set to be 60-80 ℃.

Transferring the soybean milk to be filled to a high-level tank for temporary storage, arranging a discharge port of the high-level tank 20cm higher than a feed port in the filling step, separating by a cartridge filter, completing unpowered filling, and warehousing or loading and transporting after conventional sterilization.

Example 2A Water-saving high protein soymilk and method for producing the same

Unlike example 1, the soy milk crude and the emulsion are blended simultaneously in this example. The specific steps of the emulsion blending comprise: according to the mass percentage of the crude soybean milk, 0.25 percent of stabilizer mono-diglycerol fatty acid ester, 0.5 percent of xanthan gum and sucrose fatty acid ester and 7 percent of white sugar are uniformly mixed and then added into an emulsifying tank with high-speed shearing, 0.5 percent of coconut oil and 0.05 percent of salt are added, 0.03 percent of sodium tripolyphosphate and 0.02 percent of sodium carbonate are added to adjust the pH value, the emulsion is transferred into a blending tank after uniform mixing, the emulsifying tank is washed by a small amount of water, and then flushing fluid is also poured into the blending tank, so that zero waste of materials is realized as far as possible. Transferring the crude soybean milk to a blending tank, and mixing the crude soybean milk with the emulsion to a constant volume. Detecting the pH value and temperature of the mixed liquid in the blending tank, controlling the pH value to be 7.5 and the temperature to be 70 ℃, observing the level meter Rong Yewei (the allowable error is +/-3 mm, and the record table needs to be annotated) when the mixed slurry in the blending tank is not fluctuated, and stirring for 5min after the constant volume is finished.

The parameters of the first homogenization and the second homogenization of the soymilk products with different flavors and packaging selection are slightly different, which is related to factors possibly influenced by the variety of the products, the packaging of the products and the like. In the research and development process of the applicant, gradient comparison of different homogenization pressures, temperatures and time is carried out, the gradient temperature is selected from 65, 67, 69, 71, 73, 75 and 77 ℃, the gradient pressure is selected from 40, 45, 50 and 55mpa series, the gradient homogenization time is selected from 12, 14, 16, 18 and 20min for research and development, the storage period is taken as an index, the homogenization temperature of the soymilk product with the optimal storage period effect is 75 ℃, the homogenization pressure is 55mpa, and the homogenization time is 16min, the homogenization is carried out under the optimal storage period condition, and the stable storage period of the soymilk reaches 12 months.

Example 3A Water-saving high protein soymilk and method for producing the same

Please refer to the schematic process flow diagram of the production method of water-saving high-protein soymilk shown in fig. 1.

Preparing peeled soybeans: placing the selected soybeans without peculiar smell, mildew browning and macroscopic impurities into a 85 ℃ environment for baking for about 1h, cooling the baked soybeans to the normal temperature within 30min, removing the outer skins of the soybeans by adopting high-speed negative-pressure hot air after the outer skins of the soybeans are all wrinkled and are separated from cotyledons to obtain peeled soybeans, and determining that the peeling rate of the peeled soybeans is 99%.

Pre-treating, soaking the above processed peeled semen glycines in 80 deg.C pure water at an addition mass ratio of 1:9, and adding NaHCO ₃ Adjusting the pH value of the solution to 9.0, and soaking for 1h to obtain the bean product to be ground.

The remaining operating steps are the same as in example two.

Example 4A water-saving high protein red date soymilk and its production method

The procedure of this example is essentially the same as example 3, except that an appropriate amount of red date powder or red date juice is added to the blending tank just prior to homogenization. The homogenizing process parameters are adjusted to 50mpa, the temperature of two-time homogenization is 65 ℃, and the homogenizing time is 13min. In various other embodiments, the auxiliary flavoring agents added to the blending tank may be oat auxiliary, solid wheat essence, fruit flavoring agent and flower flavoring agent.

Example 5A Water-saving high protein wheat-flavored soymilk and method for producing the same

The procedure of this example is substantially the same as example 2, except that:

the preparation method of peeled semen glycines comprises: and (3) putting the black beans into a temperature of 88 ℃ for baking, cooling the baked soybeans to the normal temperature within 40min, and peeling at a high speed and under negative pressure to obtain peeled soybeans with the peeling rate of more than 99%.

Pre-treating, soaking peeled black beans in pure water at 90 ℃, wherein the adding mass ratio of the peeled black beans to the pure water is 1:9, adding edible alkali solution to adjust the pH value to 9.0, and soaking for 48min to obtain bean products to be ground;

the second fine grinding is carried out by coating water on bean dregs and pure water according to the mass ratio of 1:1, and the soybean milk boiling tank is a 100 ℃ steam soybean milk boiling tank, and the soybean milk boiling time is 10min. Both the coarse grinding and the first fine grinding were carried out at 90 ℃. The conditions of the first homogenization and the second homogenization are both 80 ℃ and 50MPa. In the filling process, a discharge hole of the high-level tank is arranged 18cm higher than a position of a feed hole in the filling step.

Example 6A Water-saving high protein fruity soymilk and method of producing the same

the preparation method of peeled semen glycines comprises: and (3) placing the soybeans in a temperature of 85 ℃ for baking, cooling the baked soybeans to the normal temperature within 35min, and peeling at a high speed and under negative pressure to obtain peeled soybeans with the peeling rate of more than 98%.

Pre-treating, soaking peeled soybean in pure water of 85 deg.C, the adding mass ratio of peeled soybean to pure water is 1:8, adding edible alkali solution to adjust pH value to 9.0, soaking for 70min to obtain bean product to be ground;

and during the secondary fine grinding, the bean dregs and pure water are subjected to water covering fine grinding according to the mass ratio of 1.5 to 1, the soybean milk boiling tank is a steam soybean milk boiling tank at the temperature of 98 ℃, and the soybean milk boiling time is 15min. Both the coarse grinding and the first fine grinding were carried out at 80 ℃. The conditions of the first homogenization and the second homogenization are both 70 ℃ and 45MPa. In the filling process, the position of the discharge hole of the high-level tank is 20cm higher than the position of the feed hole in the filling step.

Comparative example 1 soymilk and method for producing the same

100 kg of bean paste is dried at 95 ℃ until the water content is 6-7%, and is cooled to below 40 ℃ by wind, and is soaked in water which is about 3 times of the bean paste until the bean paste has no hard core, the water is filtered out, the bean paste is hot-boiled in hot water at 80-85 ℃ for 20 seconds, then the bean is ground by 300 kg of water to obtain soybean milk slurry, 105 kg of white granulated sugar and 0.5 kg of salt are added into a soybean milk boiling tank, the soybean milk is boiled to a boiling state at 100 ℃ by introducing steam, and the soybean milk is continuously homogenized for three times, wherein the homogenizing pressure is respectively 15MPa, 40MPa and 40MPa.

The soymilk obtained in examples 1 to 6 and comparative example 1 was subjected to the measurement of color, taste and odor, texture, protein, fat, urease activity, total number of colonies, coliform group and Staphylococcus aureus, and the measurement results are shown in Table 1, and the measurement methods are listed as follows:

the color, taste, smell and tissue state belong to sensory detection items, and are determined by referring to a related detection method of GB/T30885-20146.1.

The protein was assayed by the first method of GB 5009.5-2016.

Fat was measured by the second method of GB 5009.6-2016.

Total solids content ^N The determination is carried out by the method of GB/T30885-20146.2.

Urease activity ^N The determination was carried out using the method described in appendix A to GB/T30885-2014.

The total number of colonies was determined by the method of GB 4789.2-2016.

Coliform bacteria were determined by the second method of GB 4789.3-2016.

Staphylococcus aureus was assayed by the second method of GB 4789.10-2016.

TABLE 1 Soy milk of examples 1 to 6 and comparative example 1 for the content of nutrients and the stable shelf life of the soy milk

As can be seen from the data in Table 1, the finished soymilk prepared by the technical scheme of the invention has high protein content, proper fat content, negative urease activity and no beany flavor, the total number of bacterial colonies, coliform bacteria and staphylococcus aureus bacterial colonies all meet the corresponding standard requirements and are lower than those of the soymilk of the comparative example, the color, taste and smell also meet the requirements, and only a small amount of standing solid matters exist, so no coagulum appears. Therefore, the preparation method of the technical scheme of the invention has the advantages of high dissolution rate of soybean protein, high protein content in the soybean milk, uniform and stable product, good sensory properties such as color, taste, smell, tissue state and the like, full inhibition of urease activity, no generation of beany flavor, proper treatment means such as soybean milk production, filling and the like of coliform groups, total bacterial colonies, staphylococcus aureus and the like, and maximum reduction.

In addition, according to the soybean milk production method, by mass ratio, 11 parts of pure water is added to 1 part of peeled soybeans at most, no wastewater is discharged in the whole production process, and the product conversion rate of the pure water is about 100%; in the existing soymilk production method adopted in comparative example 1, at least 20 parts of pure water needs to be added to 1 part of soybeans by mass ratio, and the total wastewater discharge amount in the soymilk production process reaches about 8 parts, namely the product conversion rate of pure water is only about 60%. Therefore, the method for producing the soymilk is an advanced method for producing the soymilk with water saving and high protein dissolution rate, and can produce the soymilk with soft mouthfeel, rich nutrition, stable quality and long quality guarantee period.

It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.

Claims

1. A production method of water-saving high-protein soymilk is characterized by comprising the following steps:

transferring the soymilk crude product and the emulsion to a preparation tank, flushing residual emulsion in the emulsion tank with a small amount of water, pouring the flushing liquid into the preparation tank, and fixing the volume;

carrying out primary homogenization on the primary homogenization to obtain a primary soymilk product;

transferring the primary soymilk product to a temporary storage tank for standing, and then, carrying out secondary homogenization in a second homogenizer to obtain soymilk to be filled;

2. The production method according to claim 1, wherein the second fine grinding is carried out by mixing the okara and pure water in a mass ratio of (1-2) to (0.5-1.0).

3. The production method according to claim 1, wherein the boiling tank is a steam boiling tank at 95-100 ℃ and the boiling time is 10-20 min.

4. The production method according to claim 1, wherein the rough grinding and the first fine grinding are both performed at 80 to 90 ℃.

5. The method of claim 1, wherein the dehulled soybeans are produced by a method comprising:

placing the soybeans in a temperature of 85-88 ℃ for baking;

cooling the heated and dried soybean to normal temperature within 30-40 min;

and carrying out high-speed negative pressure peeling to obtain the peeled soybeans, wherein the peeling rate of the peeled soybeans is more than 95%.

6. The production method according to claim 1, wherein the third solid-liquid separation is mechanical filtration.

7. The production method according to claim 1, wherein the conditions of the first homogenization and the second homogenization are 65-80 ℃ and 40-55 MPa.

8. The method of claim 1, wherein the step of formulating the emulsifier further comprises adding one of a wheat flavor aid, an oat flavor aid, a fruity or a fresh flower flavor aid.

9. The production method according to claim 1, wherein the high-level tank discharge port is arranged 18 to 23cm higher than the filling step feed port.

10. A water-saving high protein soymilk, characterized in that it is produced by the production method according to any one of claims 1 to 9.