Method and apparatus for extracting juice from soybeans, grains or nuts and seeds

Abstract

To provide a squeezing method and a squeezing device of soybeans, cereals or nuts and seeds capable of suppressing generation and dilation (spilled over) of foams in a heating step for immersing the soybeans, cereals or nuts and seeds, without using special immersing means or a defoaming agent for deaerating a secondary slurry, and capable of readily deaerating a gas solved in the secondary slurry.SOLUTION: A squeezing device includes, for example: a grinding device 3 for obtaining a heated secondary soybean slurry 18 by grinding a primary soybean slurry 22 in which soybeans are coarsely ground and mixed with hot water, together with the hot water; a degassing device 6 for degassing the secondary soybean slurry 18 of 40°C or higher conveyed from the grinding device 3 without heating; a heating device 8 heating the degassed secondary soybean slurry 19 to obtain a heated slurry; and a solid-liquid separator 9 for performing the solid-liquid separation of the heated slurry.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for extracting juice from soybeans, grains or nuts and seeds to produce beverages and other products. [Background technology]

[0002] Generally, when producing soy milk, soybean slurry (also called raw soybean slurry) obtained by grinding soybeans is placed in a heating kettle and boiled by heating to extract water-soluble proteins in the soybean slurry and promote thermal denaturation of the proteins, followed by solid-liquid separation. In the process of grinding soybeans and the process of transferring the soybean slurry obtained by grinding, the soybean slurry is prone to contain air bubbles, and when the soybean slurry containing air bubbles is heated in a kettle, many of the bubbles expand, rise to the surface, and spill out. Therefore, it is necessary to reduce the amount of soybean slurry charged to about half or less of the volume of the kettle, which poses a problem in that the volume of the kettle for boiling the soybean slurry cannot be used effectively.

[0003] Furthermore, the large amount of air bubbles contained in the soybean slurry hinders the transfer of heat to the soybeans, making it difficult to heat them uniformly, which can affect the quality of the soy milk obtained. Furthermore, when transferring a large amount of foamed soybean slurry to the equipment for the next process, the foam may get ahead of the soybean slurry or cavitation may occur, making it impossible to transfer the liquid, which may cause the pump transferring the soybean slurry to malfunction.

[0004] Therefore, in the past, when a batch kettle was used as a heating kettle, a method of adding an antifoaming agent (powder or liquid) before feeding the soybean slurry into the kettle or a method of adding an antifoaming agent into the kettle was generally adopted to suppress the generation of foam. However, in recent years, consumers have become more health-conscious, and there is growing demand for tofu products (including tofu that is an organic agricultural processed food) that do not use food additives such as anti-foaming agents, with the soybeans, water, and coagulants being the only ingredients used.

[0005] Therefore, Patent Document 1 proposes a soymilk-producing apparatus comprising an airtight boiling can, a pressure reducing means for reducing the air pressure inside the boiling can, and a soybean soup supplying means for supplying the soybean soup into the boiling can whose pressure has been reduced. Patent Document 1 discloses that the soybean soup can be boiled and air bubbles can be removed without using an antifoaming agent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-306104 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the secondary soybean slurry is heated in a closed pathway, such as in a continuous heating kettle, it is not possible to use an antifoaming agent along the way, making it difficult to separate the foam. Furthermore, when the soymilk-producing apparatus described in Patent Document 1 is used, a means for heating the inside of a boiling can or a means for boiling the soybean soup immediately before the boiling can is required, which increases the number of production steps and causes fluctuations in heating conditions due to scorching or clogging of the heating section, which in turn increases cleaning costs, thereby increasing the overall production cost. Furthermore, with the method described in Patent Document 1, it is difficult to deaerate even the gas dissolved in the soybean soup.

[0008] The present invention has been made in view of the above-mentioned problems, and aims to provide a method and apparatus for extracting juice from soybeans, grains or seeds, which can be applied not only to extracting juice from soybeans but also from grains or seeds, and which can suppress the generation of bubbles and expansion (overflow) in the heating step of boiling soybeans, grains or seeds, and which can easily degas gas dissolved in the secondary slurry, without using any special boiling means or antifoaming agent for degassing the secondary slurry. [Means for solving the problem]

[0009] One aspect of the present invention is a method for extracting juice from soybeans, grains, or nuts and seeds, comprising the steps of: a soaking step of soybeans, grains or nuts and seeds in warm water of 40°C or higher for a predetermined time to obtain a primary slurry; a grinding step of grinding the primary slurry with warm water to obtain a heated secondary slurry; a degassing step of degassing the secondary slurry having a temperature of 40°C or higher that has been transported from the grinding step; a heating step of heating the deaerated secondary slurry to obtain a heated slurry; a solid-liquid separation step of separating the heated slurry into solid and liquid; The present invention is characterized by having the following.

[0010] The method for extracting juice from soybeans, grains or nuts and seeds that is one aspect of the present invention may include an enzyme inactivation step in which the soybeans or the primary slurry is heated to a temperature of 70°C or higher to thermally inactivate the enzymes before or simultaneously with the grinding step.

[0011] In one embodiment of the method for extracting juice from soybeans, grains, or nuts and seeds of the present invention, the soybeans can be at least one type selected from whole soybeans, coarsely crushed soybeans obtained by roughly crushing raw soybeans, cracked soybeans obtained by dry-cracking raw soybeans, dehulled hypocotyl-cracked soybeans obtained by removing the hypocotyl and seed coat from the cracked soybeans, and pressed soybeans.

[0012] The method for extracting juice from soybeans, grains or nuts and seeds according to one embodiment of the present invention may include, between the grinding step and the deaeration step, a heating step of heating the secondary slurry so that the temperature rises to 20°C or less, or a heat retention step of keeping the secondary slurry warm.

[0013] In the method for extracting juice from soybeans, grains or nuts and seeds according to one aspect of the present invention, the secondary slurry is preferably conveyed from the grinding step to the deaeration step without being heated.

[0014] An apparatus for extracting juice from soybeans, grains, or nuts and seeds according to one embodiment of the present invention is as follows: a soaking device for soaking soybeans, grains, or nuts and seeds in hot water of 40°C or higher for a predetermined time to obtain a primary slurry; a grinding device for grinding the primary slurry together with warm water to obtain a heated secondary slurry; a degassing device for degassing the secondary slurry having a temperature of 40°C or higher, which is transported from the grinding device; a heating device for heating the deaerated secondary slurry to obtain a heated slurry; a solid-liquid separator for separating the heated slurry into solid and liquid; The present invention is characterized by having the following.

[0015] The soybean, grain or nut / seed juice extractor according to one embodiment of the present invention may include an enzyme inactivation device that heats the soybeans or the primary slurry to a temperature of 70°C or higher to thermally inactivate the enzymes.

[0016] In one embodiment of the apparatus for extracting juice from soybeans, grains or nuts and seeds of the present invention, the soaking device may be an enzyme inactivation / soaking device that also performs an enzyme inactivation step of heating the soybeans to a temperature of 70°C or higher to thermally inactivate the enzymes.

[0017] In one embodiment of the apparatus for extracting juice from soybeans, grains or nuts and seeds of the present invention, the grinding device can be an enzyme inactivation / grinding device that also performs an enzyme inactivation step of heating the primary slurry to a temperature of 70°C or higher to thermally inactivate the enzymes.

[0018] In one embodiment of the present invention, the apparatus for extracting juice from soybeans, grains or nuts and seeds preferably has, between the grinding device and the degassing device, a heating device for heating the secondary slurry to a temperature of 20°C or less, or a heat retention device for keeping the secondary slurry warm.

[0019] In the soybean, grain or nut / seed juice extractor according to one aspect of the present invention, the secondary slurry is preferably conveyed from the grinding device to the degassing device without being heated.

[0020] In one embodiment of the present invention, the soybeans in the soybean, grain, or nut and seed juice extractor can be at least one type selected from whole soybeans, coarsely crushed soybeans obtained by roughly crushing raw soybeans, cracked soybeans obtained by dry-cracked raw soybeans, dehulled hypocotyl cracked soybeans obtained by removing the hypocotyls and seed coats from the cracked soybeans, and pressed soybeans.

[0021] The soybean, grain or nut seed juicing apparatus according to one embodiment of the present invention may have, for example, a slurry tank between the grinding apparatus and the degassing apparatus for temporarily storing and stirring the secondary slurry.

[0022] The soybean, grain or nut seed juicing apparatus according to one embodiment of the present invention may have, for example, a conveying device between the grinding device and the degassing device, which supplies the secondary slurry to the degassing device at a temperature of 40°C or higher.

[0023] In the apparatus for extracting juice from soybeans, grains or nuts and seeds according to one aspect of the present invention, the conveying device is preferably a positive displacement metering pump.

[0024] In the apparatus for extracting juice from soybeans, grains or nuts and seeds according to one aspect of the present invention, the heating device is preferably a continuous heating device that heats the secondary slurry in a stepwise manner in a closed atmosphere.

[0025] In the apparatus for extracting juice from soybeans, grains or nuts and seeds according to one aspect of the present invention, the grinding device is preferably a grinding device made of stainless steel. [Effects of the Invention]

[0026] The method and apparatus for extracting soybeans, grains, or nuts and seeds of the present invention involve soaking soybeans (whole soybeans, crushed soybeans, cracked soybeans, pressed soybeans, etc.) in warm water at 40°C or higher for a predetermined time to obtain a primary slurry, which is then ground to obtain a heated secondary slurry. While this secondary slurry contains a large amount of air, the present invention easily removes dissolved gases without the need for special boiling methods or antifoaming agents, suppressing foaming and expansion during the heating process and allowing for uniform, even cooking. Therefore, the present invention is useful for producing differentiated products, such as products made without antifoaming agents and organic agricultural processed foods. Furthermore, the present invention allows for the extraction of juice using the minimum amount of antifoaming agent necessary, which is expected to reduce costs amid rising raw material costs. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a soymilk producing apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a soymilk producing apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present inventors conducted extensive research into a method for efficiently removing air bubbles entrained in a secondary slurry of soybeans, grains, or nuts and seeds during grinding without using special heating means or antifoaming agents. As a result, the present inventors discovered that it is efficient to perform a degassing step to remove air bubbles before heating the secondary slurry to obtain a heated slurry. However, with a typical specification range of a vacuum generator selected based on the relationship between water temperature and water vapor pressure, such as a water-sealed vacuum pump commonly used in the food industry, it is difficult to achieve efficient degassing at a vacuum level equivalent to the saturated water vapor pressure of water at the seal water temperature when the seal water temperature is between 15°C and 20°C. Therefore, in order to efficiently degas the air bubbles (including dissolved gases) in the secondary slurry using a degassing device, the secondary slurry must be at a temperature of 40°C or higher.

[0029] Therefore, in the present invention, before the degassing step, for example, a step of heating soybeans to inactivate the enzyme, or a step of soaking soybeans, grains, or nuts and seeds in warm water to swell them, regardless of whether the enzyme has been inactivated or not, is carried out. By using the secondary slurry that has then reached a predetermined temperature (at least 40°C), degassing can be performed efficiently without heating for degassing.

[0030] While the present invention is preferably a method that does not require the use of an antifoaming agent, it can also be applied to a method that uses the minimum amount of antifoaming agent necessary. This allows the amount of antifoaming agent to be reduced compared to conventional methods, and economic benefits can be expected. In particular, a liquid antifoaming agent that can achieve defoaming action even when the water temperature is 60°C or lower can be used in the minimum amount necessary, and the effect can be obtained by using an extremely small amount, for example, 0.1 to 3.0 g per kg of raw soybeans. In this case, even with a concentrated secondary soybean slurry (soybean soup) with a soymilk concentration of 12 to 20% Brix (2.0 to 5 kg of water per kg of raw soybeans, a water addition ratio of 2.0 to 5 times), it works synergistically with the degassing effect of the degassing device, making it possible to improve the degassing effect.

[0031] It is also preferable to adjust the soaking temperature of the soybeans, grains or nuts and seeds so that the secondary slurry is at 40°C or higher in the degassing step, and to transport the secondary slurry from the grinding step to the degassing step without heating it. However, during the transport of the secondary slurry, a warming step of keeping the secondary slurry warm, or a heating step of maintaining the temperature or heating the secondary slurry so that the temperature rises to 20°C or lower, may be carried out.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0033] [Method for extracting juice from soybeans, grains or nuts and seeds] First Embodiment Hereinafter, as a first embodiment of the method and apparatus for extracting juice from soybeans, grains or nuts and seeds according to the present invention, a method for extracting juice from soybeans (a method for producing soy milk) and an apparatus for producing soy milk (an apparatus for producing soy milk) will be described in detail with reference to the drawings.

[0034] FIG. 1 is a schematic diagram showing the configuration of a soymilk producing apparatus according to a first embodiment of the present invention. As shown in Figure 1, the soymilk production apparatus 1 according to the first embodiment comprises a soaking device 2 that soaks ground soybeans 17 at a predetermined temperature for a predetermined time to obtain a primary soybean slurry (primary slurry) 22, a grinding device 3 that grinds the primary soybean slurry 22 together with warm water to obtain a heated secondary soybean slurry (secondary slurry) 18, a slurry tank 4 that temporarily stores and stirs the obtained secondary soybean slurry 18, a first pump (transporting device) 5 that transports the secondary soybean slurry 18 in the slurry tank 4 to a degassing device 6 for the next process, a degassing device 6 that degass the secondary soybean slurry 18, a second pump 7 that transports the degassed secondary soybean slurry 19, a heating device 8 that heats it to obtain a boiled soybean slurry, and a solid-liquid separation device (pressure extractor) 9 that separates the obtained boiled soybean slurry into soybean lees and soymilk.

[0035] When soymilk is produced using the soymilk-producing apparatus 1 configured as described above, first, in the soaking device 2, ground soybeans 17 are mixed with hot water heated to a predetermined temperature (e.g., 40°C or higher) and soaked for, for example, 1 second to 3 hours, preferably 1 minute to 1 hour, to obtain a primary soybean slurry 22 (soaking step). Next, the swollen primary soybean slurry 22 is supplied to the attrition-grinding device 3 and ground with the hot water to obtain a secondary soybean slurry 18 (so-called raw soybean slurry) (attrition-grinding step). The attrition-grinding device 3 can be a typical attrition-grinding device, such as a stainless steel screen mill (hammer mill) or a stone mill made of stainless steel or sintered abrasive grains. However, because abrasive grains may chip and become foreign matter, or the abrasive grains may damage the machine and shorten its lifespan, it is preferable to use a stainless steel attrition-grinding device that does not chip abrasive grains. The attrition-grinding device may be a submerged attrition-grinding device that entrains little air during attrition, but the present invention also allows for the above-mentioned typical attrition-grinding method, which entrains a lot of air during attrition. Since the secondary soybean slurry (raw soybean slurry) contains air, its specific gravity is preferably 1.00 or less and 0.50 or more. If the specific gravity is greater than 1.00, there is little need for degassing, but if it is less than 0.50, it will be difficult to pump.

[0036] The secondary soybean slurry 18 is then temporarily stored in the slurry tank 4 and agitated by the agitator 10, and the hot water and soybeans are uniformly mixed before being transported by the first pump 5 to the degassing device 6 via the flow rate control valve 11. In the first embodiment, a rotary pump is used as the first pump 5, but the type of pump is not particularly limited as long as it is a positive displacement pump that can transport solids and liquids. For example, commonly used positive displacement metering pumps such as gear pumps, diaphragm pumps, plunger pumps, and rotary positive displacement uniaxial eccentric screw pumps (Mono Pump (registered trademark)) can be used.

[0037] A vacuum pump 14 is connected to the degassing device 6, and the pressure inside the degassing device 6 can be reduced by this vacuum pump 14. The timing of the reduction in pressure is not particularly limited, and it is preferable to adjust the pressure inside the degassing device 6 to a predetermined level in advance by the vacuum pump 14, and then supply the secondary soybean slurry 18 at 40°C or higher from the nozzle 12 into the degassing device 6 in a reduced pressure state below atmospheric pressure. Although not shown, a vacuum adjustment valve for adjusting the pressure inside the degassing device can may be provided. If the heating device 8 for heating the deaerated secondary soybean slurry 19 is a continuous type, it is preferable to supply the secondary soybean slurry 18 into the deaerator 6 from the nozzle 12 after reducing the pressure inside the deaerator 6 in advance.

[0038] When the secondary soybean slurry 18 is continuously supplied into the deaerator 6 while the pressure inside the deaerator 6 is reduced, the secondary soybean slurry 18 supplied into the deaerator 6 is sprayed toward the inner wall of the deaerator 6 by the nozzle 12. The secondary soybean slurry 18 boils as it is supplied into the deaerator 6, which has been reduced in pressure, thereby removing the air contained in the secondary soybean slurry 18. After colliding with the inner wall of the deaerator, the secondary soybean slurry 18 flows down along the inner wall. When the secondary soybean slurry 18 collides with the inner wall, the impact generates new bubbles, but since the cooling jacket 13 is provided on the outer periphery of the deaerator 6 and the gas that forms the bubbles is water vapor, the secondary soybean slurry 18 is cooled by the can wall as it flows down inside the cooling jacket 13, and the water vapor bubbles generated upon collision condense and disappear (deaerating process).

[0039] The saturated steam pressure at the inlet temperature of the secondary soybean slurry (see, for example, the "Steam Table" of the Japan Society of Mechanical Engineers: 40°C: 7.375 kPa, 50°C: 12.335 kPa, 60°C: 19.92 kPa, 70°C: 31.162 kPa, 80°C: 47.36 kPa, 90°C: 70.109 kPa, 100°C: 101.325 kPa) causes the water to instantly boil, lowering the temperature of the secondary soybean slurry to the temperature at the pressure inside the degassing device pipe, while simultaneously removing the dissolved air. As mentioned above, a cooling jacket 13 is provided on the outer surface of the degassing device 6, so that the remaining bubbles containing a large amount of water vapor that have foamed and risen to the surface are cooled and condense or shrink (degassing process). Note that in this specification, a continuous degassing device is described as the preferred form of degassing device.

[0040] Thereafter, while the pressure inside the deaerator 6 remains reduced, the secondary soybean slurry inside the can is continuously removed by a second pump 7, and the deaerated secondary soybean slurry 19 is transported to a heating device 8. In the heating device 8, the secondary soybean slurry 19 is heated in stages using steam or the like, but since there is no generation of bubbles or expansion in the secondary soybean slurry 19, it is heated evenly without unevenness, allowing for the extraction of water-soluble proteins and the thermal denaturation of proteins to be carried out uniformly, and a slurry-like boiled soybean slurry (heated slurry) to be obtained (heating process). The secondary soybean slurry can be supplied to and removed from the deaerator 6 in a batchwise manner, but continuous operation is preferred as this allows for stable pressure reduction. Thereafter, the boiled soybean paste is subjected to solid-liquid separation by the solid-liquid separator 9, and soybean lees and soy milk are obtained (solid-liquid separation step). The type of second pump 7 that transports secondary soybean slurry 19 to heating device 8 is not particularly limited, and the same pump as first pump 5 can be used.

[0041] This embodiment includes a soaking process in which soybeans (whole soybeans, crushed soybeans, cracked soybeans, pressed soybeans, etc.) are mixed and soaked in warm water. The primary soybean slurry 22 obtained from this soaking process is then milled with water, warm water, or hot water to produce a heated secondary soybean slurry 18. Without further heating after the milling process, the secondary soybean slurry 18 can be transported at 40°C or higher into a deaerator 6, whose internal pressure is set to a minimum pressure of 7.375 kPa (water vapor pressure at 40°C), preferably 2-3°C lower than the temperature of the transported secondary soybean slurry. The transported secondary soybean slurry passes through a flow control valve 11 and a nozzle 12. As it falls along the inner wall of the pipe, the water rapidly evaporates, removing the heat of vaporization. This lowers the temperature of the secondary soybean slurry and simultaneously removes minute air bubbles and dissolved gases. As a result, air bubbles contained in the secondary soybean slurry 18 can be easily and efficiently removed.

[0042] Thus, according to this embodiment, there is no need to use an antifoaming agent in the heating step to obtain the soybean paste, and the generation of bubbles during the heating step can be easily suppressed. In this embodiment, the heating device used in the heating step is not particularly limited, and for example, a continuous heating device that heats the deaerated secondary soybean slurry 19 in a stepwise manner in a closed atmosphere can be used. Since it is generally difficult to use an antifoaming agent in such a continuous heating device, this continuous heating device is suitable for use when using the soymilk production method according to this embodiment. Liquid antifoaming agents can also be injected using a positive displacement metering pump, and in this embodiment, the amount of antifoaming agent added can be kept to the minimum necessary to obtain a quality improvement effect that compensates for fluctuations in raw material quality.

[0043] In order to expel the air bubbles contained in the secondary soybean slurry 18 using the deaerator 6, the temperature of the secondary soybean slurry 18 when it is conveyed to the deaerator 6 should be 40°C or higher, but a temperature of 70°C or higher is preferred when it is desired to obtain soy milk with little unpleasant flavor, such as a soy milk beverage, because this has the effect of deactivating enzymes. There is no particular upper limit to the temperature of the secondary soybean slurry 18 when it is conveyed to the deaerator 6, and it is preferably set to, for example, 100°C or lower, and more preferably to 90°C or lower for operational safety reasons.

[0044] In the present invention, known methods can be used to obtain the heated secondary soybean slurry 18. For example, in addition to the method of soaking cracked soybeans 17 in warm water as shown in the first embodiment, a method of soaking whole soybeans in warm water or a method of enzyme deactivation as shown in the second embodiment below may also be used. In the present invention, the soybeans used are not particularly limited, and at least one type selected from whole soybeans, coarsely crushed soybeans obtained by roughly crushing raw soybeans, cracked soybeans 17 obtained by dry cracking raw soybeans, dehulled hypocotyl cracked soybeans obtained by removing the hypocotyls and seed coats from the cracked soybeans 17, and pressed soybeans can be used. Note that pressed soybeans can be obtained, for example, by dry pressing.

[0045] Furthermore, the soy milk obtained by the production method according to the present invention may be used as a beverage, or may be used to make tofu or secondary products using soy milk, such as fried tofu and silken namaage. The production of soy milk beverages may include a step of heating soybeans to inactivate enzymes. Therefore, by using heating to inactivate enzymes, a heated secondary soybean slurry can also be obtained.

[0046] Second Embodiment Hereinafter, a soybean juicing method (soymilk manufacturing method) and a juicing apparatus (soymilk manufacturing apparatus) will be described in detail with reference to the drawings as a second embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of a soymilk manufacturing apparatus according to the second embodiment of the present invention. The soymilk manufacturing apparatus and soymilk manufacturing method according to the second embodiment will be described with reference to FIG. 2. In FIG. 2, parts that are the same as or equivalent to those in the first embodiment are given the same reference numerals in the drawing, and their description will be omitted or simplified.

[0047] The soymilk production apparatus (juice extractor) 21 according to the second embodiment has an enzyme deactivation device (enzyme deactivation and soaking device) 15, which heats soybeans 20 at a predetermined temperature for a predetermined time using a heat medium such as steam, hot water, hot air, or superheated steam, before the grinding device 3. In this case, heating with moist heat using water spray is more efficient and preferable in terms of yield than dry heat, since it serves both as an enzyme deactivator and a soaking device. Furthermore, in the first embodiment, a slurry tank 4 for temporarily storing secondary soybean slurry 18 and a first pump 5 for transporting the secondary soybean slurry 18 in the slurry tank 4 to the degassing device were provided between the grinding device 3 and the degassing device 6. However, in the second embodiment, a rotary positive displacement uniaxial eccentric screw pump (Mono Pump (registered trademark)) 16 is provided in place of the slurry tank 4 and first pump 5. As in the first embodiment, the pump used is not limited to the rotary positive displacement uniaxial eccentric screw pump, but any positive displacement metering pump such as a rotary pump, gear pump, diaphragm pump, or plunger pump can be used.

[0048] In a method for producing soymilk using the soymilk production apparatus 21 configured as described above, first, soybeans 20 are supplied into the enzyme deactivation device 15. Alternatively, a primary soybean slurry obtained by soaking the soybeans 20 in warm water may be supplied into the enzyme deactivation device 15. The enzyme deactivation device 15 is configured to be able to heat the water and soybeans 20 (or the primary soybean slurry 22) with steam or the like, and heats the supplied water and soybeans 20 (or the primary soybean slurry 22) under predetermined conditions (for example, at 70 to 100°C, for 1 to 600 seconds) (enzyme deactivation step). Note that the enzyme deactivation step at 80°C or higher can also sterilize unwanted bacteria adhering to the soybeans 20 (or the primary soybean slurry 22). Alternatively, a soaking step may be carried out sequentially after the enzyme deactivation step. The soybeans 20 (or primary soybean slurry 22) in which the enzymes endogenous to the soybeans have been thermally inactivated by the enzyme inactivation device 15 are then ground by the grinding device 3, thereby obtaining a secondary soybean slurry 18 in which warm water and the finely ground soybeans are mixed (grinding process), as in the first embodiment.

[0049] The resulting secondary soybean slurry 18 is transported by a rotary positive displacement single-shaft eccentric screw pump 16. The rotary positive displacement single-shaft eccentric screw pump 16 has the function of transporting the secondary soybean slurry 18 while uniformly mixing the hot water and raw soybean paste, and the secondary soybean slurry 18 is transported from the grinding device 3 to the deaerator 6 in a closed, non-open environment. The deaerating process in the deaerator 6 and the subsequent processes are the same as in the first embodiment.

[0050] In the second embodiment, soybeans (or primary soybean slurry) heated to 70°C or higher by the enzyme deactivation device 15 are ground with water, warm water, etc. to become secondary soybean slurry 18, which is then transported to the degassing device 6 at a temperature of at least 40°C or higher and not higher than 100°C without being heated, so that air bubbles in the secondary soybean slurry 18 can be relatively easily removed without using an antifoaming agent or a heating device for degassing. In the first and second embodiments, the secondary soybean slurry 18 is transported to the deaerator 6 without being heated, but a heat-retaining device may be disposed between the grinding device 3 and the deaerator 6 to maintain the temperature of the secondary soybean slurry 18 during transport. Furthermore, a heating device may be disposed between the grinding device 3 and the deaerator 6 to heat the secondary slurry so that the temperature rises to 20°C or less.

[0051] In the second embodiment, the enzyme deactivation device 15 is disposed before the grinding device 3, but the location at which the enzyme deactivation device 15 is installed is not limited to this. For example, a grinding device (enzyme deactivation and grinding device) 3 that also serves as the enzyme deactivation device 15 may be used to heat the primary soybean slurry after soaking to a temperature of 70°C or higher, and grind the soybeans while heating them. Even in this case, the secondary soybean slurry 18 is transported from the enzyme deactivation device to the deaerator 6 at 70 to 100°C without being heated, so that air bubbles in the secondary soybean slurry 18 can be more easily removed.

[0052] In the second embodiment, a rotary positive displacement uniaxial eccentric screw pump 16 is provided instead of the slurry tank 4 and first pump 5 described in the first embodiment. As a result, as described above, the secondary soybean slurry 18 can be transported from the grinding device 3 to the degassing device 6 in a closed environment, thereby improving hygiene compared to the first embodiment. In addition, because the slurry tank 4 is an open type, it is necessary to monitor the secondary soybean slurry 18 to prevent it from overflowing.

[0053] On the other hand, the rotary positive displacement uniaxial eccentric screw pump 16 can be set to have a larger conveying volume than the amount supplied from the grinding device 3, and can convey the secondary soybean slurry 18 to the degassing device 6 while drawing in outside air. If the secondary soybean slurry 18 is conveyed while drawing in outside air in this way, the secondary soybean slurry 18 will contain many air bubbles. However, in this embodiment, the air bubbles are discharged by the degassing device 6 before the secondary soybean slurry 18 is conveyed to the heating device 8, so the rotary positive displacement uniaxial eccentric screw pump 16 can be suitably used. Furthermore, by setting the conveying volume to be larger than the amount supplied to the rotary positive displacement uniaxial eccentric screw pump 16, clogging of the pump can be prevented and monitoring is not required. Therefore, in the present invention, the type of pump can be selected as needed.

[0054] The soymilk production method and soymilk production apparatus according to the first and second embodiments are methods and apparatus for producing soymilk by processing soybeans, but the present invention can also be applied to the production of plant-based milk using grains other than soybeans (beans such as adzuki beans, peas, green peas, fava beans, and edamame) and seeds (nuts such as peanuts, almonds, cashew nuts, hazelnuts, macadamia nuts, pistachios, pecan nuts, walnuts, and coconuts; seeds high in oil and protein such as hemp seeds, pumpkins, sunflowers, pine nuts, and sesame; millet such as pearl millet, finger millet, proso millet, foxtail millet, and Japanese barnyard millet; and pseudo-cereals such as quinoa, chia seeds, and amaranth). As with soybeans, these raw materials can be used to produce plant-based milks such as soy milk by appropriately subjecting them to pretreatment processes such as coarse grinding, grinding, and enzyme-inactivating heating, as well as soaking, hydration, grinding, degassing, separation, and heating. Some raw materials, such as peanuts, hemp seeds, and sunflowers, tend to have an undesirable grassy flavor. In such cases, the flavor can be improved by roasting the raw materials in advance or by carrying out enzyme-inactivating or degassing processes using dry or moist heat (70-100°C). For starchy beans such as adzuki beans, peas, green peas, fava beans, edamame, and immature soybeans, the soaking device and enzyme deactivation device of the present invention can be used as an enzymatic reaction saccharification device. In this case, the enzymatic reaction saccharification device is operated at a temperature of 50 to 80°C, preferably 55 to 75°C, to allow endogenous saccharifying enzymes such as β-amylase to act, thereby producing maltose and other sugars, thereby increasing sweetness. [Explanation of symbols]

[0055] 1,21 Soy milk production equipment 2 Immersion device 3 Grinding device 4. Slurry Tank 5. First Pump 6 Degassing device 7. Second pump 8 Heating device 9 Solid-liquid separator 14 Vacuum pump 15 Enzyme deactivation device 16 Rotary positive displacement uniaxial eccentric screw pump 17 Soybeans 18 Secondary soybean slurry 20 Soybeans 22 Primary soybean slurry

Claims

1. a soaking step of soybeans, grains or nuts and seeds in warm water of 40°C or higher for a predetermined time to obtain a primary slurry; a grinding step of grinding the primary slurry with warm water to obtain a heated secondary slurry; a degassing step of degassing the secondary slurry, which has a temperature of 40°C or higher and a soy milk concentration of 12 to 20% Brix and which has been transported from the grinding step; a heating step of heating the deaerated secondary slurry to obtain a heated slurry; a solid-liquid separation step of separating the heated slurry into solid and liquid; A method for extracting juice from soybeans, grains, or nuts and seeds, comprising the steps of:

2. 2. The method for extracting juice from soybeans, grains or nuts and seeds according to claim 1, further comprising an enzyme inactivation step of heating the soybeans or the primary slurry to a temperature of 70°C or higher to thermally inactivate the enzymes before or simultaneously with the grinding step.

3. 3. The method for extracting juice from soybeans, grains or nuts and seeds according to claim 1 or 2, wherein the soybeans are at least one type selected from whole soybeans, coarsely crushed soybeans obtained by roughly crushing raw soybeans, cracked soybeans obtained by dry-cracking raw soybeans, dehulled hypocotyl cracked soybeans obtained by removing the hypocotyls and seed coats from the cracked soybeans, and pressed soybeans.

4. The method for extracting juice from soybeans, grains, or nuts and seeds according to any one of claims 1 to 3, further comprising, between the grinding step and the deaeration step, a heating step of heating the secondary slurry so that the temperature rises to 20°C or less, or a heat-retaining step of keeping the secondary slurry warm.

5. The method for extracting juice from soybeans, grains or nuts and seeds according to any one of claims 1 to 3, wherein the secondary slurry is transported from the grinding step to the deaeration step without being heated.

6. a soaking device for soaking soybeans, grains, or nuts and seeds in hot water of 40°C or higher for a predetermined time to obtain a primary slurry; a grinding device for grinding the primary slurry together with warm water to obtain a heated secondary slurry; a degassing device for degassing the secondary slurry having a temperature of 40°C or higher and a soy milk concentration of 12 to 20% Brix, which is transported from the grinding device; a heating device for heating the deaerated secondary slurry to obtain a heated slurry; a solid-liquid separator for separating the heated slurry into solid and liquid; A soybean, grain or nut / seed juice extractor, comprising:

7. 7. The apparatus for extracting juice from soybeans, grains or nuts and seeds according to claim 6, further comprising an enzyme inactivation device for heating the soybeans or the primary slurry to a temperature of 70°C or higher to thermally inactivate enzymes.

8. The soybean, grain or nut or seed juicing apparatus according to claim 6, wherein the soybean soaking device is an enzyme inactivation / soaking device that also performs an enzyme inactivation step of heating the soybeans to a temperature of 70°C or higher to thermally inactivate the enzymes.

9. 7. The apparatus for extracting juice from soybeans, grains, or nuts and seeds according to claim 6, wherein the grinding device is an enzyme inactivation / grinding device that also performs an enzyme inactivation step of heating the primary slurry to a temperature of 70°C or higher to thermally inactivate the enzymes.

10. The soybean, grain or nut / seed juice extractor according to any one of claims 6 to 9, further comprising a heating device for heating the secondary slurry at a temperature of 20°C or less, or a heat-retaining device for keeping the secondary slurry warm, between the grinding device and the degassing device.

11. The apparatus for extracting juice from soybeans, grains or nuts and seeds according to any one of claims 6 to 9, wherein the secondary slurry is conveyed from the grinding device to the deaerating device without being heated.

12. The soybeans are at least one type selected from whole soybeans, coarsely crushed soybeans obtained by roughly crushing raw soybeans, cracked soybeans obtained by dry-cracking raw soybeans, dehulled hypocotyl cracked soybeans obtained by removing the hypocotyls and seed coats of the cracked soybeans, and pressed soybeans. The apparatus for extracting juice from soybeans, grains, or nuts and seeds according to any one of claims 6 to 11.

13. The soybean, grain or nut / seed juice extracting apparatus according to any one of claims 6 to 12, further comprising a slurry tank for temporarily storing and stirring the secondary slurry between the grinding device and the degassing device.

14. The soybean, grain or nut / seed juice extracting apparatus according to any one of claims 6 to 13, further comprising a conveying device between the grinding device and the degassing device, which supplies the secondary slurry to the degassing device at a temperature of 40°C or higher.

15. The soybean, grain or nut / seed extractor according to claim 14, wherein the conveying device is a positive displacement metering pump.

16. The apparatus for extracting juice from soybeans, grains, or nuts and seeds according to any one of claims 6 to 15, wherein the heating device is a continuous heating device that heats the secondary slurry in a stepwise manner in a closed atmosphere.

17. The apparatus for extracting juice from soybeans, grains or nuts and seeds according to any one of claims 6 to 16, wherein the grinding device is made of stainless steel.

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