Patent Application
20230320393
The present invention relates to a method and an apparatus for producing tofu products by using a coagulation device.
In related art, as an example of a tofu production method for producing tofu products by coagulating soymilk, as shown in
In Patent Literature 1, a tofu production method for producing silken tofu or the like in a large amount has been known in which detachability of the tofu from storage portions of a plurality of coagulation buckets provided side by side on a conveyor is improved by spraying water from fluid spray nozzles toward the storage portions. Patent Literature 2 describes that hot water is sprayed from a lid of a coagulation container or an upper side of a side wall of the coagulation container into the coagulation container to clean an inside of the coagulation container.
Patent Literature 1: JP2018-174836A
Patent Literature 2: JP2014-132902A
Incidentally, in the coagulation bucket 11 of the coagulation device 10, a coagulation step is repeated, so that an adhered coagulated product is stacked and grown on a container wall, a stirring blade, and the like a stalactite or a Baumkuchen. When the coagulation step is performed in a state where such an adhered coagulated product remains in the coagulation bucket 11, a stirring state of the soymilk changes or a coagulation state of the soymilk (a size or the like of coagulated particles) slightly changes, so that quality of a product (for, example, deep-fried tofu or hard tofu) may be affected, and in some cases, a mass of the adhered coagulated product may also be mistaken as a foreign matter mixed into the coagulation bucket 11. Therefore, in the related art, it is necessary to perform an operation to periodically scrape off the adhered coagulated product in the coagulation bucket 11 by a person.
In the tofu production method described in Patent Literature 1, cleaning of the storage portions of the coagulation buckets each including no liquid discharge port for the silken tofu is mainly described, but cleaning of a coagulation bucket including a liquid discharge port for deep-fried tofu or hard cotton tofu as in the present invention is not mentioned.
In a tofu production method described in Patent Literature 2, it is described that a coagulated product adhered to an inside of the container is washed away by washing with water, but a method for sending a coagulated product dispersion liquid to a next step to use the dispersion liquid is not described.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a method and an apparatus for producing tofu products, which can effectively clean and remove an adhered coagulated product in a coagulation bucket.
The above object of the present invention is achieved by the following configurations.
According to the present invention, by spraying water from a water spray device, an adhered coagulated product in a coagulation bucket can be effectively cleaned and removed, and growth of the adhered coagulated product in the coagulation bucket can be prevented. Since a dispersion liquid of the adhered coagulated product is mixed with a coagulated product for use, a yield rate, a yield, and quality of tofu products can be improved.
Hereinafter, an example of a method for producing tofu products according to the present invention will be described in detail with reference to drawings. Since the present invention is obtained by improving a configuration of a coagulation device in a tofu production apparatus shown in
As shown in
In the coagulation device 10a, the plurality of coagulation buckets 11 are fixed to a base (not shown) in a vertical posture, and the soymilk supplied from the soymilk supply pipe 12 and the coagulant supplied from the coagulant supply pipe 13 are mixed in each of the coagulation buckets 11, so that a coagulated product S is produced. The coagulated product S is discharged, through the coagulated product discharge pipe 14 connected to a lower portion of the coagulation bucket 11, to a forming step that is a subsequent step.
As shown in
A stirring device 18, which stirs the soymilk and the coagulant and breaks the coagulated product S, is provided in the coagulation bucket 11. The stirring device 18 includes a stirring shaft 18b to which a stirring blade 18a is attached, and the stirring shaft 18b penetrates the lid 17 and is driven by a drive motor (not shown) connected above. The stirring device 18 may be configured to be also drivable in a vertical direction.
Further, the water spray device 15 connected to the cleaning water supply pipe 16 is provided in an upper portion in the coagulation bucket 11. The water spray device 15 includes a ring-shaped water spray pipe disposed along an inner peripheral surface of an upper portion of the cylindrical portion 11a of the coagulation bucket 11, and can clean both a liquid contact portion in the coagulation bucket 11 with which the soymilk, the coagulant, and the coagulated product S come into contact, and splashes adhered to a liquid non-contact portion other than the liquid contact portion. In particular, since the lid 17 is provided, not only a lower portion of the water spray pipe but also an upper portion of the water spray pipe can be washed with water, and when a spray ball nozzle or the like (see a later description) is provided as necessary, an effect of washing with water can be further improved.
The liquid non-contact portion means inner surfaces of an upper inner wall and the lid 17 of the coagulation bucket 11, and the liquid contact portion includes an inner wall of the coagulation bucket 11, the stirring blade 18a, the stirring shaft 18b, a soymilk feed port 12a of the soymilk supply pipe 12, a baffle plate 30 (see
Water sprayed from the water spray device 15 is water for food production, may be clean water such as tap water or well water, and is not particularly limited to distilled water, sterile water filtered through a membrane, and the like. The sprayed water may be water of 0° C. to 100° C., preferably hot water of 40° C. to 100° C. heated by the cleaning water supply device, and more preferably hot water of 60° C. to 95° C. in terms of a bacteriostatic effect and practicality. By using the hot water, it is also possible to obtain effects of killing germs and preventing propagation of the germs, and an effect of thermally insulating a bucket.
As the sprayed water, vapor condensed water obtained by recovering water vapor with which the coagulation bucket 11 is filled may be used.
The clean water may be used for cleaning or washing, and can also be used so as to contain a quality improving agent (a food additive such as a pH adjusting agent or a puffing accelerator, or a food material). Separated water (also referred to as “a supernatant liquid” or “exuding water”) separated from a soymilk coagulated product is used as the sprayed water directly, or is used as the sprayed water after being handled hygienically by filtration, disinfection, sterilization, or the like, so that it is possible to expect a water saving effect and an effect of not cooling the soymilk coagulated product and members such as pipes and the bucket.
A pump 19 such as a metering pump or a self-priming pump that can convey the coagulated product S without crushing the coagulated product S as much as possible is provided ahead of the coagulated product discharge pipe 14, but the coagulated product S may be naturally discharged. The pump 19 is not particularly limited as long as the pump 19 is a pump having a self-priming force, such as a rotary pump, a mohno pump, a vane pump, a high viscosity liquid transfer pump, a tubing pump, or a gear pump. A discharge valve (not shown) (an automatic opening and closing valve such as a ball valve, a butterfly valve, or a gate valve) is provided in the coagulated product discharge pipe 14 so as to be openable and closable. The coagulated product discharge pipe 14 may have a downward gradient of 1% or more, and preferably 5% or more, with respect to a horizontal direction. A size of a discharge pipe is 2.0 inches or more, and is preferably 2.5 inches to 3 inches.
A member subjected to surface polishing or surface treatment processing is provided on a portion in the coagulation bucket 11 to which the coagulated product S is easily adhered. Specifically, examples of the portion to which the coagulated product is easily adhered (a portion on which the coagulated product easily remains) include the liquid contact portion, the water spray device 15, and the like, and the liquid contact portion includes the inner wall of the coagulation bucket 11, the stirring device 18 including the stirring blade 18a and the stirring shaft 18b, the baffle plate 30 to be described later, the soymilk feed port 12a, and the like. A shape of the stirring blade 18a is not limited to a general propeller type of two to four blades, and may be in a form in which an effect of crushing the coagulated product is also obtained. A stirring program such as forward rotation, reverse rotation, or multi-speed rotation may be appropriately included, and is not particularly limited.
As the surface polishing, buff mirror polishing or electrolytic polishing may be used. As the surface treatment processing, Teflon (registered trademark) coating, ceramic coating, DLC coating, sandblast processing, or water-repellent processing (a contact angle of water is 90 degrees or more) by which a fine uneven structure that achieves a lotus effect is created may be used as necessary.
The coagulation bucket 11 may include a thermal insulation unit that thermally insulates a container wall. As the thermal insulation unit, a jacketed tank including an air layer and a vacuum layer, a jacketed tank in which hot water of 40° C. to 100° C. flows through a jacket, or a thermal insulation tank in which a thermal insulation material is applied can be applied. As a result, the container wall is not cooled, adhesion of the coagulated product S can be prevented, and the homogeneous coagulated product S having high water retention property can be formed.
In the coagulation device 10a configured as described above, as shown in
Then, when the coagulated product S is aged for a predetermined time in the coagulation bucket 11, the discharge valve is opened and the pump 19 is activated (step S6), so that the coagulated product S is sent to a forming device for the subsequent step.
In the forming step that is the subsequent step, the coagulated product S is supplied to a storage tank of a continuous forming machine, or is directly supplied, without passing through the storage tank, to a water draining machine that separates the supernatant liquid (whey) from the coagulated product, or is directly supplied, in a total amount filling method, to a hopper of a dispenser that equally dispenses the coagulated product S onto a lower fabric, or is directly supplied onto the lower fabric of the continuous forming machine.
After the coagulated product S is sent to the forming device, an adhered coagulated product Sa (see
Here, for example, when a product having a low soymilk concentration, such as deep-fried tofu, hard tofu, or dried-frozen tofu, is produced in which a concentration of the soymilk used in the coagulation device is 1 wt % to 10 wt % and is preferably 2 wt % to 7 wt %, as shown in (a) of
On the other hand, in a case of a product having a soymilk concentration of more than 10 wt %, as shown in (b) of
By providing the water spray device 15 in the upper portion of the coagulation bucket 11, the adhered coagulated product Sa adhered to the side surface of the coagulation bucket 11 is flushed out with water from a water spray nozzle when the coagulated product S of the soymilk and the coagulant is conveyed, so that the adhered coagulated product Sa can be conveyed and a yield rate can be improved. By flushing out with the water from the water spray nozzle, it is possible to reduce the adhered coagulated product Sa adhered to the container wall of the coagulation bucket 11, to prevent propagation of the germs (hygienic each time coagulation is performed), and to further prevent growth of the adhered coagulated product.
A coagulated product dispersion liquid containing the washed-away adhered coagulated product Sa and the sprayed water may be mixed with the coagulated product S, or may be separately discarded.
When the sprayed water and the coagulated product dispersion liquid remain in the coagulation bucket 11, the soymilk concentration is lowered in next metering of the soymilk, which impairs a taste of the tofu and leads to a decrease in quality. Therefore, it is preferable that the sprayed water and the coagulated product dispersion liquid (washing liquid) are completely discharged from the coagulation bucket 11 before next feeding of the soymilk.
The coagulation bucket 11 includes the above thermal insulation unit or is subjected to surface polishing or surface coating treatment, so that an amount of the adhered product is reduced, and it is possible to perform adjusting to reduce an amount of water during washing with water.
When washing with water is not performed periodically, the coagulated product S is gradually adhered to and further accumulated on the inner wall of the coagulation bucket 11, the stirring blade 18a, the baffle plate 30 to be described later, and the like, so that a stirring effect may change as a production time increases, sizes and a particle size distribution of particles of the coagulated product S may change, and the quality of the product may be affected. On the other hand, by periodically washing with water and preferably washing with water for each batch, and mixing a washing solution with the coagulated product S in a storage tank including a stirrer, it is possible to prevent quality of a fried product from changing due to water draining and a change in water content in the tofu.
The coagulated product S is gradually hardened over time while being adhered, and sometimes becomes a discolored mass. When the mass drops and flows to the next step, not only the tofu in which the mass is mixed is deformed and a loss is caused, but also a complaint may be made due to mixing in of a foreign matter. By washing with water, it is possible to prevent adhesion of the coagulated product S and it is also possible to prevent the coagulated product S from becoming the mass, so that such problems can be prevented from occurring.
After production is completed, in a cleaning step, water spray nozzles can spray not only water but also a chemical liquid (caustic soda or the like). Therefore, an improvement in cleaning effect of cleaning in place (CIP: a method for cleaning by pouring a cleaning agent without disassembling a device) can also be expected. In a method in the related art, a chemical liquid is only allowed to pass through a bucket, the chemical liquid is added at most in an amount larger than an amount of soymilk, and immersion cleaning is performed while rotating the stirring blade 18a. However, when the water spray nozzle is included, the upper portion of the coagulation bucket 11 can be cleaned by adjusting an amount of water and a flow rate. In particular, when CIP cleaning is performed with the chemical liquid, it is more preferable to include a lid. The chemical liquid after the cleaning is discarded to an outside (step S8).
In the above embodiment, cleaning of the inside of the coagulation bucket 11 is started after the coagulated product S is conveyed to the next step, but as in first to third modifications shown in
In the modification shown in
An amount of the sprayed water is preferably 0.1% to 1% with respect to the soymilk in the coagulation bucket 11. As a result, the coagulated product dispersion liquid including the adhered coagulated product Sa which is washed away by the water sprayed from the water spray device 15 is conveyed to the next step through the coagulated product discharge pipe 14 (step S9).
The coagulated product dispersion liquid passing through the coagulated product discharge pipe 14 and the previously discharged coagulated product S are discharged together and uniformly mixed in a storage tank provided downstream of the pump 19. In this case, it is also possible to discharge all of the coagulated product dispersion liquid prior to the next metering of the soymilk, and it is also possible to convey the coagulated product S in the coagulation bucket 11 to the next step without unnecessarily lowering the soymilk concentration and without lowering the quality.
As shown in
By spraying the cleaning water from the middle, in a case of deep-fried tofu, a part (so-called “land return”) of return water (also referred to as “added water”) added at the end of a boiling step is obtained, little fresh air is mixed, heat denaturation of a protein is prevented by slightly lowering a temperature of the coagulated product, so that a skin of the deep-fried tofu slightly becomes soft and easily stretches (easily puffs), and effects of improving the quality, improving the yield rate, and further reducing a burden of drainage can be obtained. By mixing the coagulated product with washed water obtained by washing with water, a yield is also improved by an amount that corresponds to the recovered adhered product although small.
However, when the amount of water used for washing is too much or a water temperature is lowered, there are also adverse effects that a temperature of the coagulated product S is lowered, the tofu is not well drained, and the product does not stretch. When the cleaning water is hot water, an effect of supplying air is low, but a soymilk temperature is stabilized due to a thermal insulation effect.
The water spray device 15 is not limited to a water spray pipe type described above, and may be a shower ball type shown in
The water spray device 15 may include a high pressure nozzle that can perform cleaning with high pressure water of 1 MPa to 10 MPa.
For example, the water spray device 15 may include a ball type or rotary type spray nozzle, may spray an alkaline or acidic cleaning chemical liquid from the nozzle to the inside of the bucket 11 during CIP cleaning, and may be used for circulation cleaning or rinsing using the chemical liquid. For finishing, water vapor, sodium hypochlorite water, hypochlorous acid water, or the like may also be sprayed from the nozzle to perform sterilization.
Further, as in a modification shown in
In the modification shown in
In this case, some of nozzle holes of the shower nozzle may be holes having directivity, through which the water can be sprayed toward the stirring shaft 18b, the stirring blade 18a, and the baffle plate 30.
The present invention is not limited to the above embodiments, and modifications, improvements, and the like are possible as appropriate. In addition, a material, a shape, a dimension, a numerical value, a form, the number, a disposition position, and the like of each of components in the above embodiments are not limited as long as the present invention can be achieved.
For example, the coagulation bucket 11 preferably includes the lid 17, but may not include a lid as long as a cleaning liquid from a nozzle is not scattered out from the upper portion.
In the above embodiments, the deep-fried tofu, the hard tofu, and the dried-frozen tofu are exemplified as target products, but the tofu product that is a target of the present invention may be a product obtained by breaking and forming a half-curded coagulated product or a soft pudding-like coagulated product as shown in (a) or (b) of
Further, in the above embodiment, a fixed bucket coagulation machine in which the plurality of coagulation buckets are fixed to the base has been described, but a round type bucket coagulation machine in which a plurality of coagulation buckets rotate around a base may be used. In a case of the round type bucket coagulation machine, a coagulated product discharge pipe may be provided, but a form in which discharging is performed by inverting the bucket is preferable.
The present application is based on Japanese Patent Application No. 2020-149764 filed on Sep. 7, 2020, the contents of which are incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-149764 | Sep 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/031255 | 8/25/2021 | WO |
