Method for manufacturing folded protein products, apparatus for manufacturing folded protein products, and manufacturing parts for folded protein products.

Abstract

To provide a production method, a production apparatus and production parts of a folded protein product capable of realizing texture and chewiness close to those of meat.SOLUTION: A folded protein product is produced by using two cooling dies having different cross-sectional shapes so as to generate a belt-like protein product in the first cooling die, and deform the belt-like protein product to a folded state in the second cooling die. The folded protein product extends in a lengthwise direction while forming a plurality of ridge-valley folded portions by reciprocating a plurality of times in a vertical direction in a region of a substantially constant height. The folded protein product having a folded external appearance has texture and chewiness further close to those of meat.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a production method, a production apparatus, and production parts for producing a folded protein product capable of providing a favorable texture. [Background Art]

[0002] It has been conventionally known that protein food products are produced using an extruder.

[0003] For example, a so-called "meat analog" is known as a protein food produced using an extruder. This product is obtained by heating and pressurizing vegetable protein such as wheat gluten or soy protein with an extruder to organize the protein, thereby realizing texture and chewiness similar to meat.

[0004] In general, meat (animal muscle tissue) has a microstructure in which muscle fibers (muscle cells) are bundled, and it is considered that this structure as well as the thickness, hardness, elasticity and the like of individual fibers provide the chewiness and texture of meat. For this reason, several attempts have been made to produce protein products having a fiber bundle structure, in order to achieve texture and chewiness similar to meat.

[0005] Patent Document 1 discloses a method for producing a meat-like food using soy protein as a raw material with an extruder. According to this method, water is mixed into a soy protein raw material, the soy protein is organized through kneading, shearing, heating and pressurizing steps, and a flat belt-shaped soy protein product is extruded through a cooling die. The flat belt-shaped (including sheet-shaped and noodle-shaped) soy protein product obtained by this method has a porous structure similar to the structure of meat, and realizes texture and chewiness similar to meat.

[0006] Patent Document 2 also discloses a method for producing a flat belt-shaped protein food with specified product temperature and product thickness by using an extruder and a cooling die.

[0007] Patent Document 3 discloses a method for producing a protein food product (fish paste product resembling grilled eel) having an appearance similar to grilled eel, by performing press molding after extrusion molding. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] European Patent Publication EP2706867 [Patent Document 2] Japanese Patent Publication No. 2020-018279 [Patent Document 3] Japanese Patent Publication No. 2020-022367 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The inventors of this case have discovered that by using two cooling dies with different cross-sectional shapes, a protein product can be extruded into a flat strip and then deformed into a folded shape. Furthermore, they have discovered that a protein product with such a folded appearance has a texture and chewiness that is even closer to that of meat.

[0010] This invention was conceived based on the above findings. The object of this invention is to provide a method for producing a folded protein product that can achieve a texture and chewiness similar to meat, as well as a manufacturing apparatus and manufacturing parts. [Means for solving the problem]

[0011] The present invention relates to a method for producing a folded protein product, comprising the steps of: heating a protein raw material and a liquid raw material while kneading them; extruding the kneaded and heated protein raw material and liquid raw material into a strip shape while cooling them in a first cooling die to produce a strip-shaped protein product; and further cooling the strip-shaped protein product extruded by the first cooling die in a second cooling die to deform it into a folded shape to produce a folded protein product, wherein the extrusion passage of the first cooling die has a cross-sectional shape in which the height is less than the width, the molding passage of the second cooling die also has a cross-sectional shape in which the height is less than the width, the height of the extrusion passage of the first cooling die is 10 mm or less, and the height of the molding passage of the second cooling die is 2 to 20 times the height of the extrusion passage of the first cooling die.

[0012] According to the inventor's findings, by using two cooling dies with different cross-sectional shapes, a strip-shaped protein product can be produced in the first cooling die, and then the strip-shaped protein product can be deformed into a folded shape in the second cooling die to produce a folded protein product. Such a folded protein product has a texture and chewiness that is even closer to that of meat.

[0013] Furthermore, according to the inventor's knowledge, the extrusion passage of the first cooling die has a cross-sectional shape in which the height is less than the width, and the molding passage of the second cooling die also has a cross-sectional shape in which the height is less than the width, and the height of the extrusion passage of the first cooling die is 10 mm or less, and the height of the molding passage of the second cooling die is 2 to 20 times the height of the extrusion passage of the first cooling die, which are necessary conditions for producing a folded protein product.

[0014] Furthermore, it is preferable that the extrusion passage of the first cooling die and the molding passage of the second cooling die are continuous.

[0015] According to this, the force of extrusion molding on the first cooling die (the force that pushes the strip-shaped protein product out of the first cooling die) can be effectively utilized as a force that deforms the strip-shaped protein product within the second cooling die, causing it to fold.

[0016] Furthermore, it is preferable that the width of the molding passage of the second cooling die is equal to the width of the extrusion molding passage of the first cooling die.

[0017] According to this method, the direction of deformation of the strip-shaped protein product within the second cooling die can be limited to the height direction (up and down direction), thereby enabling the efficient production of folded protein products.

[0018] For example, the cross-sectional shape of the extrusion passage of the first cooling die and / or the cross-sectional shape of the molding passage of the second cooling die is rectangular, a rectangle with at least some rounded corners, or oval.

[0019] Furthermore, for example, the step of heating the protein raw material and the liquid raw material while kneading them is carried out using an extruder. In this case, the temperature at which the protein raw material and the liquid raw material are heated while kneading them is 130°C or higher, the temperature of the strip-shaped protein product immediately after exiting the first cooling die is 100°C to 130°C (preferably 110°C to 120°C), and the temperature of the folded protein product immediately after exiting the second cooling die is 90°C to 110°C (preferably 95°C to 100°C), which are effective conditions for producing the folded protein product.

[0020] Furthermore, for example, the protein raw material is concentrated soy protein, the liquid raw material is water, and the mixing ratio of the protein raw material to the liquid raw material is 1:0.9 to 1:3.3.

[0021] According to this method, it is possible to manufacture folded soy protein products that have a texture and chewiness that are even closer to that of meat.

[0022] Furthermore, the present invention provides an apparatus for producing a folded protein product, comprising: an extruder that heats a protein raw material and a liquid raw material while kneading the same; a first cooling die that receives the protein raw material and the liquid raw material kneaded and heated by the extruder, and produces a band-shaped protein product by extrusion-molding the protein raw material and the liquid raw material into a band shape in cooperation with the extruder while cooling the protein raw material and the liquid raw material; and a second cooling die that receives the band-shaped protein product extrusion-molded by the first cooling die, and produces a folded protein product by deforming the band-shaped protein product into a folded shape in cooperation with the extruder while cooling the band-shaped protein product, wherein the extrusion passage of the first cooling die has a cross-sectional shape having a height lower than a width, the forming passage of the second cooling die also has a cross-sectional shape having a height lower than a width, the height of the extrusion passage of the first cooling die is 10 mm or less, and the height of the forming passage of the second cooling die is 2 to 20 times the height of the extrusion passage of the first cooling die.

[0023] Furthermore, the present invention provides a manufacturing part for a folded protein product attached to an extruder, comprising: a first cooling die that receives a protein raw material and a liquid raw material kneaded and heated by the extruder, and produces a band-shaped protein product by extrusion-molding the protein raw material and the liquid raw material into a band shape in cooperation with the extruder while cooling the protein raw material and the liquid raw material; and a second cooling die that receives the band-shaped protein product extrusion-molded by the first cooling die, and produces a folded protein product by deforming the band-shaped protein product into a folded shape in cooperation with the extruder while cooling the band-shaped protein product, wherein the extrusion passage of the first cooling die has a cross-sectional shape having a height lower than a width, the forming passage of the second cooling die also has a cross-sectional shape having a height lower than a width, the height of the extrusion passage of the first cooling die is 10 mm or less, and the height of the forming passage of the second cooling die is 2 to 20 times the height of the extrusion passage of the first cooling die.

[0024] Further, the present invention relates to a folded protein product that extends in the length direction while forming a plurality of valley and ridge folded portions by reciprocating a plurality of times in the vertical direction within a substantially constant height range.

[0025] Such a folded protein product can be manufactured using the aforementioned manufacturing method, manufacturing apparatus and manufacturing parts. Moreover, such a folded protein product can achieve a texture and chewiness that are even closer to those of meat.

[0026] Preferably, the spacing between adjacent valley and ridge folded portions is 5 mm or less. Such a complex shape cannot be achieved by press molding, and is effective in achieving a texture and chewiness closer to those of meat.

[0027] Further, preferably, the folded protein product can be deformed so as to substantially evenly widen the spacing between adjacent valley and ridge folded portions in the length direction. Such a property is exhibited when adjacent (continuous) valley and ridge folded portions are extrusion-molded in the continuous direction, which cannot be achieved by press molding, and is effective in achieving a texture and chewiness even closer to those of meat.

[0028] Further, preferably, the repeating pitch of adjacent valley and ridge folded portions is 2.0 mm to 25 mm. Said numerical range is an effective condition for achieving a texture and chewiness even closer to those of meat.

[0029] Further, preferably, the substantially constant height range of the folded protein product is 3.0 to 30 mm. Said numerical range is also an effective condition for achieving a texture and chewiness even closer to those of meat.

[0030] Further, preferably, the width of the folded protein product is substantially constant. Said condition is also an effective condition for achieving a texture and chewiness even closer to those of meat.

[0031] Preferably, the protein content is 45% by mass or more on a dry matter basis, and the moisture content is 50-78% by mass. These conditions are also effective in achieving a texture and chewiness that is even closer to that of meat.

[0032] The folded protein product described above can also be limited to a product-by-process based on the manufacturing method described above. That is, the folded protein product is formed by extruding a strip-shaped protein product, which is formed by cooling using a first cooling die, and then further molding it using a second cooling die while cooling, wherein the extrusion passage of the first cooling die has a cross-sectional shape in which the height is less than the width, and the molding passage of the second cooling die also has a cross-sectional shape in which the height is less than the width, the height of the extrusion passage of the first cooling die is 10 mm or less, and the height of the molding passage of the second cooling die is 2 to 20 times the height of the extrusion passage of the first cooling die. [Effects of the Invention]

[0033] According to the present invention, after producing a strip-shaped protein product in a first cooling die, the strip-shaped protein product can be deformed into a folded shape in a second cooling die to produce a folded protein product. Such a folded protein product has a texture and chewiness that is even closer to that of meat. [Brief explanation of the drawing]

[0034] [Figure 1] This is a flowchart of a method for producing a folded protein product according to one embodiment of the present invention. [Figure 2] This is a schematic diagram of a manufacturing apparatus for a foldable protein product according to one embodiment of the present invention. [Figure 3] This is a photograph of the folded protein product from Example 1. [Figure 4] This is a photograph of the folded protein product from Example 2. [Figure 5] This is a photograph of the folded protein product of Comparative Example 1. [Figure 6] This is a photograph of the folded protein product from Example 5. [Figure 7] This is a photograph of the folded protein product of Example 6. [Figure 8] This is a photograph of the folded protein product from Example 7. [Figure 9] This is a photograph of the folded protein product from Example 8. [Figure 10] This is a photograph of the folded protein product from Example 9. [Figure 11] This is a photograph of the folded protein product of Example 10. [Figure 12] This photograph shows the deformation performance of a folded protein product in the longitudinal direction. [Modes for carrying out the invention]

[0035] Embodiments of the present invention will be described below with reference to the drawings.

[0036] Figure 1 is a flow chart of a method for producing a foldable protein product according to one embodiment of the present invention, and Figure 2 is a schematic diagram of a manufacturing apparatus for a foldable protein product according to one embodiment of the present invention.

[0037] As shown in Figures 1 and 2, the method for producing the folded protein product of this embodiment comprises: a step of heating a protein raw material and a liquid raw material while kneading them using an extruder 30 (STEP 1); a step of extruding the protein raw material and liquid raw material, which have been kneaded and heated using the extruder 30, into a strip shape while cooling them in a first cooling die 10 to produce a strip-shaped protein product B (STEP 2); and a step of deforming the strip-shaped protein product B extruded by the first cooling die 10 into a folded shape while further cooling it in a second cooling die 20 to produce a folded protein product F (STEP 3).

[0038] A feature of the present invention is that the extrusion molding passage 12 of the first cooling die 10 has a cross-sectional shape in which the height is lower than the width, and the molding passage 22 of the second cooling die 20 also has a cross-sectional shape in which the height is lower than the width. Furthermore, the height of the extrusion molding passage 12 of the first cooling die 10 is 10 mm or less, and the height of the molding passage 22 of the second cooling die 20 is 2 to 20 times the height of the extrusion molding passage 12 of the first cooling die 10.

[0039] In this embodiment, the cross-sectional shape of the extrusion passage 12 of the first cooling die 10 is oval, the height of the extrusion passage 12 of the first cooling die 10 is 1.5 mm, and the width of the extrusion passage 12 of the first cooling die 10 is 50 mm.

[0040] On the other hand, in this embodiment, the cross-sectional shape of the molding passage 22 of the second cooling die 20 is also oval, the height of the molding passage 22 of the second cooling die 20 is 20 mm (13.33 times the height of the extrusion molding passage 12 of the first cooling die 10), and the width of the molding passage 22 of the second cooling die 20 is 50 mm.

[0041] Furthermore, in this embodiment, the length of the extrusion passage 12 of the first cooling die 10 is equal to the length of the molding passage 22 of the second cooling die 20, which is 100 mm.

[0042] Furthermore, in this embodiment, the inner surface of the extrusion passage 12 of the first cooling die 10 is made of stainless steel, and the inner surface of the molding passage 22 of the second cooling die 20 is made of stainless steel.

[0043] Furthermore, in this embodiment, the first cooling die 10 and the second cooling die 20 are continuously connected such that the side walls defining the widths of both molding passages 12 and 22 are aligned in the longitudinal direction, and the extrusion molding passage 12 of the first cooling die 10 and the molding passage 22 of the second cooling die 20 are continuous in the longitudinal direction. In the height direction, the extrusion molding passage 12 of the first cooling die 10 is positioned to open at an intermediate position between the molding passage 22 of the second cooling die 20.

[0044] As shown in Figure 2, the first cooling die 10 is configured to cool the extrusion molding passage 12 by allowing a coolant (for example, cooling water at 20°C) to flow from two coolant inlets 14a and 14b to two coolant outlets 16a and 16b.

[0045] Similarly, the second cooling die 20 is also configured to cool the molding passage 22 by allowing refrigerant (for example, cooling water at 20°C) to flow from two refrigerant inlets 24a and 24b to two refrigerant outlets 26a and 26b.

[0046] The first cooling die 10 and the second cooling die 20 described above were manufactured by the inventors as manufacturing parts for a folded protein product to be attached to an extruder. The upstream side of the extrusion passage 12 of the first cooling die 10 (the side not connected to the molding passage 22 of the second cooling die 20) is attached to a known extruder to constitute a manufacturing apparatus for a folded protein product.

[0047] In this embodiment, a "KEI-45" extruder manufactured by Kowa Kogyo (screw diameter 46 mm, L / D = 25) was used as the extruder 30. The protein raw material and liquid material are fed into the barrel 32 of the extruder 30. The barrel 32 rotates at a rotational speed of about 150 rpm to knead the protein raw material and liquid material, while an internal heater (not shown) heats the kneaded mixture. In this embodiment, the barrel 32 heats the protein raw material and liquid material to a high temperature of about 160°C while kneading them.

[0048] Furthermore, the extruder 30 of this embodiment is configured to extrude the mixture (kneaded and heated protein raw material and liquid raw material) toward the first cooling die 10 at an extrusion speed of 16 kg / h.

[0049] The dashed line in Figure 2 conceptually illustrates the state in which the strip-shaped protein product B begins to be molded into a folded protein product F. As shown by this dashed line, when the leading edge of the strip-shaped protein product B comes into contact with the bottom wall of the molding passage 22 due to gravity, it receives frictional resistance from the bottom wall, and the forward movement of the leading edge of the strip-shaped protein product B temporarily stops. Meanwhile, since the extrusion of the strip-shaped protein product B from the first cooling die 10 continues, the strip-shaped protein product B begins to fold vertically (height direction) within the molding passage 22, becoming a folded protein product F. In parallel with this deformation into a folded shape, the extrusion (extrusion force) of the strip-shaped protein product B from the first cooling die 10 intermittently or continuously moves the entire folded protein product F forward towards the exit of the molding passage 22.

[0050] (Embodiment of a folded protein product) In this embodiment, concentrated soy protein (Arcon S, manufactured by ADM Japan Co., Ltd.) was used as the protein raw material, and water was used as the liquid raw material. The mixing ratio of concentrated soy protein (protein raw material) to water (liquid raw material) was set to 3:7 by mass (an example within the range of 1:0.9 to 1:3.3). The protein content of the concentrated soy protein used was 72%.

[0051] In other words, in this embodiment, concentrated soy protein (protein raw material) was supplied into the barrel 32 of the extruder 30 at a supply rate of 5 kg / h, and water (liquid raw material) was supplied at a supply rate of 11 kg / h.

[0052] Then, these concentrated soy protein (protein raw material) and water (liquid raw material) were heated while being kneaded in barrel 32 and extruded towards the extrusion molding passage 12 of the first cooling die 10 at an extrusion rate of 16 kg / h. The temperature of the kneaded material at the outlet of the extruder 30 was 141°C.

[0053] The kneaded material, continuously subjected to the extrusion force from the extruder 30, was extruded into a strip shape while being cooled as it passed through the extrusion molding passage 12 of the first cooling die 10, resulting in the strip-shaped protein product B. The temperature of the strip-shaped protein product B at the exit of the first cooling die 10 was 114°C.

[0054] The strip-shaped protein product B continues to receive the extrusion force from the extruder 30, while being cooled as it passes through the molding passage 22 of the second cooling die 20. As it receives intermittent (approximately periodic) frictional resistance from the bottom and top walls of the molding passage 22, it is deformed into a folded shape to become a folded protein product F. The temperature of the folded protein product F at the exit of the second cooling die 20 was 98°C.

[0055] The folded protein product F manufactured as described above is Example 1, and is shown in Figure 3.

[0056] As shown in Figure 3, the folded protein product F extends in the longitudinal direction while forming multiple peak-and-valley folded sections by repeatedly moving back and forth in the vertical direction within a substantially constant height range (a height range of 20 mm), and the spacing between adjacent peak-and-valley folded sections is extremely dense (5 mm or less). On the other hand, the folded protein product F can be deformed in the longitudinal direction to widen the spacing between adjacent peak-and-valley folded sections to be substantially uniform.

[0057] Furthermore, as shown in Figure 3, the folded protein product F has a repeating pitch of approximately 5 mm between adjacent peaks and valleys (an example of 2.0 mm to 25 mm). Also, the folded protein product F has a nearly constant width (in the direction perpendicular to the plane of the paper in Figure 3).

[0058] Furthermore, the folded protein product F has a protein content of 72% by mass on a dry matter basis (the remaining 28% by mass on a dry matter basis consists of carbohydrates, ash, lipids, etc.) and a moisture content of 70% by mass. The protein content on a dry matter basis was calculated, for example, using a textured protein gel obtained from concentrated soy protein and water, by measuring the protein content by the Kjeldahl method and the moisture content by the dry heat method, thereby determining the protein content in components other than water.

[0059] The folded protein product F described above, having multiple peaks and valleys, can achieve a texture and chewiness that is even closer to that of meat. In particular, the fact that the spacing between adjacent peaks and valleys is very close is effective in achieving a texture and chewiness that is even closer to that of meat. Furthermore, the property that it is possible to deform the product so that the spacing between adjacent peaks and valleys in the longitudinal direction is widened almost uniformly is also effective in achieving a texture and chewiness that is even closer to that of meat.

[0060] Furthermore, having a repeating pitch of approximately 5 mm between adjacent ridge and valley fold sections is also effective in achieving a texture and chewiness that is even closer to that of meat. According to the inventors of this invention, it is preferable that the repeating pitch of adjacent ridge and valley fold sections be between 2.0 mm and 25 mm.

[0061] Furthermore, the fact that the height range of the folded protein product is approximately 30 mm is also effective in achieving a texture and chewiness that is even closer to that of meat. According to the inventors of this invention, the height range of the folded protein product is preferably 3.0 to 30 mm.

[0062] Furthermore, the fact that the width of the folded protein product is approximately constant is also effective in achieving a texture and chewiness that is even closer to that of meat.

[0063] Furthermore, a protein content of 72% by mass on a dry weight basis and a moisture content of 70% by mass are also effective in achieving a texture and chewiness that is even closer to that of meat. According to the inventors of this invention, it is preferable that the protein content be 45% by mass or more on a dry weight basis and the moisture content be 50-78% by mass.

[0064] The terms "height method" and "height range" are based on the orientation during manufacturing, but the product may be packaged and transported in any orientation, such as lying on its side, during distribution.

[0065] (Suitable temperature control range) In the extruder 30, the concentrated soy protein (protein raw material) mixed with water (liquid raw material) undergoes denaturation upon heating, becoming a textured protein. The textured protein is a highly fluid sol at high temperatures, but solidifies into a gel upon subsequent cooling in the cooling dies 10 and 20.

[0066] Tissue proteins possess both gel-like and sol-like properties within a temperature range of 90°C to 130°C. By deforming these tissue proteins within this temperature range before they completely solidify, a new form can be imparted to them. This invention is based on the inventor's findings.

[0067] More specifically, according to the inventors' findings, the temperature of the protein raw material and liquid raw material immediately after exiting the extruder 30 is preferably 130°C or higher, the temperature of the strip-shaped protein product B immediately after exiting the first cooling die 10 is preferably 100°C to 130°C, and the temperature of the folded protein product F immediately after exiting the second cooling die 20 is preferably 90°C to 110°C.

[0068] (Examples and comparative examples regarding protein content) According to the inventor's findings, if the protein content is too low, sufficient gel-like and / or sol-like properties will not appear, making it difficult to deform into a foldable shape.

[0069] According to the inventor's findings, the protein content required to obtain a folded protein product is 45% by mass or more on a dry weight basis, preferably 48% by mass or more, and more preferably 50% by mass or more. A higher protein content on a dry weight basis is preferable for the folded protein product, and there is no upper limit to it; for example, it may be 100% by mass. Within this range, swelling is suppressed, and a folded protein product can be obtained that extends in the length direction while forming multiple peaks and valleys by reciprocating multiple times in the vertical direction within a substantially constant height range.

[0070] The method for measuring protein content is not particularly limited, and any known method can be applied. Examples include the Kjeldahl method, combustion method, BCA method, Bradford method, and Lowry method. Similarly, the method for measuring the dry weight of tissue protein is not particularly limited, and any known method can be applied. For example, tissue protein can be collected in a wide-mouthed container such as a beaker or petri dish, placed in a dry heat dryer with the opening still open, dry-dried at 200°C for 4 hours, the mass of the container is measured, and the dry weight can be determined by subtracting the mass of the container measured beforehand (dry heat method). The "protein content on a dry matter basis" of the tissue protein can then be calculated from the protein content obtained by the above method and the moisture content obtained by the above method.

[0071] In the aforementioned Example 1, the protein content determined by the Kjeldahl method is 21.6% by mass, and the moisture content determined by the dry heat method is 70% by mass, so the protein content on a dry matter basis is 72% by mass (21.6 ÷ (1 - 0.7) = 72).

[0072] Example 2, shown in Figure 4, is obtained by substituting 30% by mass of the concentrated soy protein (protein raw material) in Example 1 with corn starch, so that the ratio of concentrated soy protein (protein raw material) is 70% by mass to 30% of corn starch. In Example 2, the protein content determined by the Kjeldahl method is 15% by mass, and the moisture content determined by the dry heat method is 70% by mass, so the protein content on a dry matter basis is 50% by mass.

[0073] As shown in Figure 4, the folded protein product F' of Example 2 also extends in the longitudinal direction while forming multiple peak-and-valley folded sections by reciprocating multiple times in the vertical direction within a substantially constant height range (a height range of 20 mm), and the spacing between adjacent peak-and-valley folded sections is extremely dense (5 mm or less). On the other hand, the folded protein product F' can also be deformed in the longitudinal direction so as to widen the spacing between adjacent peak-and-valley folded sections to be substantially uniform.

[0074] Furthermore, as shown in Figure 4, the folded protein product F' has a repeating pitch of approximately 5 mm between adjacent peaks and valleys (an example of 2.0 mm to 25 mm). Also, the width of the folded protein product F' (in the direction perpendicular to the plane of the paper in Figure 4) is approximately constant.

[0075] The folded protein product F' of Example 2 also has multiple peaks and valleys, which helps to achieve a texture and chewiness even closer to that of meat. In particular, the very close spacing between adjacent peaks and valleys is effective in achieving a texture and chewiness even closer to that of meat. Furthermore, the property that it is possible to deform the product so that the spacing between adjacent peaks and valleys in the longitudinal direction is widened almost uniformly is also effective in achieving a texture and chewiness even closer to that of meat.

[0076] In contrast, Comparative Example 1, shown in Figure 5, is prepared by replacing 40% of the concentrated soy protein (protein raw material) in Example 1 with corn starch, resulting in a ratio of 60% concentrated soy protein (protein raw material) to 40% corn starch. In Comparative Example 1, the protein content determined by the Kjeldahl method is 12.9%, and the moisture content determined by the dry heat method is 70%, resulting in a protein content of 43% by mass on a dry matter basis.

[0077] As shown in Figure 5, in Comparative Example 1, the protein content was too low, resulting in insufficient gel-like and / or sol-like properties, and the object was not deformed into a foldable shape.

[0078] The results described above are summarized in Table 1 below.

[0079] [Table 1]

[0080] (Examples and comparative examples regarding moisture content) According to the inventor's findings, if the water content is too low, the gel-like state becomes too rigid and is difficult to deform into a folded shape within the second cooling die 20. On the other hand, if the water content is too high, the gel-like state becomes too soft, and the textured protein extruded into a strip shape within the first cooling die 10 still exhibits fluidity and is difficult to deform into a folded shape within the second cooling die 20.

[0081] According to the inventor's findings, the moisture content required to obtain a folded protein product is 50 to 78% by mass, preferably 55 to 76% by mass, and more preferably 60 to 75% by weight. Within this range, swelling is suppressed, and a folded protein product can be obtained that extends in the longitudinal direction while forming multiple peaks and valleys by reciprocating multiple times in the vertical direction within a substantially constant height range.

[0082] The method for measuring the moisture content is not particularly limited, and any known method can be applied. For example, the moisture content can be determined by taking tissue protein in a wide-mouthed container such as a beaker or petri dish, placing it in a dry heat dryer with the opening still open, dry drying it at 200°C for 4 hours, and then dividing the mass obtained by subtracting the mass after drying from the mass before drying by the mass before drying.

[0083] In the aforementioned Example 1, concentrated soy protein (protein raw material) was supplied into the barrel 32 of the extruder 30 at a supply rate of 5 kg / h, water (liquid raw material) was supplied at a supply rate of 11 kg / h, and the mixture (kneaded and heated protein raw material and liquid raw material) was extruded toward the first cooling die 10 at an extrusion rate of 16 kg / h (the moisture content was 70%).

[0084] In Example 3, concentrated soy protein (protein raw material) was supplied to the barrel 32 of the extruder 30 at a supply rate of 5 kg / h, water (liquid raw material) was supplied at a supply rate of 14 kg / h, and the mixture (kneaded and heated protein raw material and liquid raw material) was extruded toward the first cooling die 10 at an extrusion rate of 19 kg / h (the moisture content was 75%).

[0085] In Example 3, a folded protein product extending in the longitudinal direction was obtained by making multiple vertical movements within a substantially constant height range, thereby forming multiple peaks and valleys.

[0086] In Example 4, concentrated soy protein (protein raw material) was supplied to the barrel 32 of the extruder 30 at a supply rate of 5 kg / h, water (liquid raw material) was supplied at a supply rate of 4.5 kg / h, and the mixture (kneaded and heated protein raw material and liquid raw material) was extruded toward the first cooling die 10 at an extrusion rate of 9.5 kg / h (the moisture content was 50%).

[0087] In Example 4, too, a folded protein product extending in the longitudinal direction was obtained by making multiple vertical movements within a substantially constant height range, thereby forming multiple peaks and valleys.

[0088] In Comparative Example 2, concentrated soy protein (protein raw material) was supplied to the barrel 32 of the extruder 30 at a supply rate of 5 kg / h, water (liquid raw material) was supplied at a supply rate of 18 kg / h, and the mixture (kneaded and heated protein raw material and liquid raw material) was extruded toward the first cooling die 10 at an extrusion rate of 23 kg / h (the moisture content was 80%).

[0089] In Comparative Example 2, it was not possible to obtain a folded protein product that extends in the longitudinal direction while forming multiple peaks and valleys by repeatedly moving back and forth in the vertical direction within a substantially constant height range.

[0090] In Comparative Example 3, concentrated soy protein (protein raw material) was supplied to the barrel 32 of the extruder 30 at a supply rate of 5 kg / h, water (liquid raw material) was supplied at a supply rate of 4 kg / h, and the mixture (kneaded and heated protein raw material and liquid raw material) was extruded toward the first cooling die 10 at an extrusion rate of 9 kg / h (the moisture content was 48%).

[0091] In Comparative Example 3, it was not possible to obtain a folded protein product that extends in the longitudinal direction while forming multiple peaks and valleys by repeatedly moving back and forth in the vertical direction within a substantially constant height range.

[0092] The results described above are summarized in Table 2 below.

[0093] [Table 2]

[0094] (Examples and comparative examples regarding the sizes of the molding passages 12 and 22 of each cooling die 10 and 20) As shown in Tables 3 and 4 and Figures 6 to 11 below, even if the size of the rectangular cross-sectional molding passages 12 and 22 of each cooling die 10 and 20 is changed, a folded protein product can be manufactured if the height of the extrusion molding passage 12 of the first cooling die 10 is lower than the width, the height of the molding passage 22 of the second cooling die 20 is lower than the width, the height of the extrusion molding passage 12 of the first cooling die 10 is 10 mm or less, and the height of the molding passage 22 of the second cooling die 20 is 2 to 20 times the height of the extrusion molding passage 12 of the first cooling die 10. Note that the outlet temperature in Table 3 refers to the temperature of the kneaded material, strip-shaped protein product, or folded protein product passing through the outlet, and is the temperature measured by a contact thermometer installed at each part. (In Examples 5 to 10 and Comparative Examples 5 to 7, the same conditions as in Example 1 were adopted, except for the size of the rectangular cross-sectional molding passages 12 and 22 of each cooling die 10 and 20.)

[0095] [Table 3]

[0096] [Table 4]

[0097] (Examples relating to the shapes of the molding passages 12 and 22 of each cooling die 10 and 20) According to the inventors of this invention, the cross-sectional shape of the extrusion passage 12 of the first cooling die 10 is not limited to a rectangle with right angles at its corners, but may be a rectangle with at least some of its corners rounded, or an oval shape with continuous radii at the top and bottom corners. Similarly, the cross-sectional shape of the molding passage 22 of the second cooling die 20 is not limited to a rectangle with right angles at its corners, but may be a rectangle with at least some of its corners rounded, or an oval shape with continuous radii at the top and bottom corners.

[0098] Furthermore, in the above-described embodiment, the exit region of the extrusion molding passage 12 of the first cooling die 10 has a step in the height direction relative to the inlet region of the molding passage 22 of the second cooling die 20, but a radius may be provided in this step. Alternatively, a part of the exit region of the extrusion molding passage 12 of the first cooling die 10 may have a shape that tapers in the height direction toward the molding passage 22 of the second cooling die 20.

[0099] (Further deformation characteristics of folded protein products) As described above, the folded protein product according to the present invention can preferably be deformed to widen the spacing between adjacent peaks and valleys in the longitudinal direction to be approximately uniform. This property appears when adjacent (continuous) peaks and valleys are extruded in the direction of continuity, and is not achievable by press molding, while being effective in achieving a texture and chewiness that is even closer to meat.

[0100] For example, Figure 12(a) shows the state of the 7th embodiment immediately after it exits the second cooling die 20. By pulling both ends with both hands, it is possible to deform it so that the spacing between adjacent peaks and valleys in the longitudinal direction is widened to be approximately equal, as shown in Figure 12(b).

[0101] (Variations of protein sources) The protein raw material can be applied to the present invention as long as it has sol-forming properties upon heating and gel-forming properties upon cooling. For example, it is not limited to plant-based proteins such as those derived from oilseeds or grains, but may also include animal-derived protein raw materials such as meat or fish.

[0102] Specifically, plant-based or animal-based protein raw materials separated and purified from agricultural products such as soybeans, peas, wheat, chickpeas, and broad beans, as well as poultry such as cattle, pigs, and chickens, and seafood such as tuna, mackerel, and sardines, can be used. More specifically, for example, powders of agricultural products such as defatted soy flour and pea flour, fillets or minced meat of beef, pork, chicken, tuna, mackerel, and sardines, or their dried powders, or mixtures thereof, can be used.

[0103] Furthermore, any other raw materials can be mixed with the protein raw material, as long as they do not inhibit the sol-forming and gel-forming properties of the protein. For example, grains such as wheat and corn, potatoes such as sweet potatoes and potatoes, starch separated and purified from these crops, and modified starch obtained by chemical treatment, heat treatment, or enzymatic treatment can be mixed in. In addition, edible water-soluble components such as salt, sucrose, and amino acids, thickening polysaccharides such as guar gum and tamarind gum, emulsifiers, and spices can also be mixed in. The amount of the mixture (auxiliary raw materials) depends on its protein content, but it is preferably about 40% by mass or less, and should be adjusted so that the protein content on a dry matter basis in the folded protein product is 45% by mass or more.

[0104] (Variations of liquid raw materials) The liquid raw material plays a role in adjusting the moisture content of the mixture, and is preferably water. The moisture content of the mixture affects the sol-forming and gel-forming properties of the protein. The liquid raw material may contain liquid oils and water-soluble components, to the extent that they do not inhibit the sol-forming and gel-forming properties of the protein. When the liquid raw material contains liquid oils and water-soluble components, the moisture content in the mixture (protein raw material and liquid raw material) is determined by subtracting the mass of these components from the mass of the liquid raw material.

[0105] (Supplementary information about the Extruder 30) The extruder 30 is preferably a twin-screw extruder capable of heating and kneading simultaneously. The screw configuration is preferably a combination of a kneading disc and a reverse screw in order to increase the shear force and sufficiently organize the protein material.

[0106] The heating temperature of barrel 32 is preferably adjusted so that the temperature of the kneaded material reaches 130°C to 170°C. The outlet pressure of barrel 32 is 3 to 70 kg / cm². 2 It is preferable that it be adjusted to this. [Explanation of Symbols]

[0107] 10. First cooling die 12 Extrusion passage 14a Refrigerant Inlet 14b Refrigerant inlet 16a Refrigerant outlet 16b Refrigerant outlet 20 Second cooling die 22 Molding passage 24a Refrigerant Inlet 24b Refrigerant inlet 26a Refrigerant outlet 26b Refrigerant outlet 30 Extruder 32 barrels B. Transgenic Protein Products F. Folded protein products F' Folded protein products

Claims

1. A method for producing a folded protein product, A process of heating while kneading protein raw materials and liquid raw materials, A process to produce a strip-shaped protein product by extruding kneaded and heated protein raw materials and liquid raw materials into a strip shape while cooling them in a first cooling die, A step of producing a folded protein product by further cooling and deforming a strip-shaped protein product extruded by the first cooling die in a second cooling die, Equipped with, The extrusion passage of the first cooling die has a cross-sectional shape in which the height is less than the width, The molding passage of the second cooling die also has a cross-sectional shape in which the height is less than the width. The height of the extrusion passage of the first cooling die is 1.5 mm or more and 10 mm or less. The height of the molding passage of the second cooling die is 2 to 20 times the height of the extrusion molding passage of the first cooling die. The mixing ratio of the protein raw material to the liquid raw material is 1:0.9 to 1:3.

3. A method for producing a folded protein product characterized by the following.

2. The extrusion passage of the first cooling die and the molding passage of the second cooling die are continuous. A method for producing a folded protein product according to feature 1.

3. The width of the molding passage of the second cooling die is equal to the width of the extrusion passage of the first cooling die. A method for producing a folded protein product according to claim 1 or 2, characterized by the present invention.

4. The cross-sectional shape of the extrusion passage of the first cooling die, and / or the cross-sectional shape of the molding passage of the second cooling die, is rectangular, a rectangle with at least some rounded corners, or oval. A method for producing a folded protein product according to any one of claims 1 to 3.

5. The step of heating the protein raw material and the liquid raw material while kneading them is carried out using an extruder. The temperature at which the protein raw material and the liquid raw material are heated while being kneaded is 130°C or higher. The temperature of the strip-shaped protein product immediately after exiting the first cooling die is 100°C to 130°C. The temperature of the folded protein product immediately after exiting the second cooling die is 90°C to 110°C. A method for producing a folded protein product according to any one of claims 1 to 4.

6. The protein raw material is concentrated soy protein. The aforementioned liquid raw material is water. A method for producing a folded protein product according to any one of claims 1 to 5.

7. An extruder that heats and kneads protein raw materials and liquid raw materials, A first cooling die receives the protein raw material and liquid raw material kneaded and heated by the extruder, and, in cooperation with the extruder, extrudes the protein raw material and liquid raw material into a strip shape while cooling them to produce a strip-shaped protein product. A second cooling die receives the strip-shaped protein product extruded by the first cooling die and, while cooling the strip-shaped protein product, works in cooperation with the extruder to deform the strip-shaped protein product into a folded shape to produce a folded protein product, Equipped with, The extrusion passage of the first cooling die has a cross-sectional shape in which the height is less than the width, The molding passage of the second cooling die also has a cross-sectional shape in which the height is less than the width. The height of the extrusion passage of the first cooling die is 1.5 mm or more and 10 mm or less. The height of the molding passage of the second cooling die is 2 to 20 times the height of the extrusion molding passage of the first cooling die. The mixing ratio of the protein raw material to the liquid raw material is 1:0.9 to 1:3.

3. A manufacturing apparatus for folded protein products characterized by the following.

8. The extrusion passage of the first cooling die and the molding passage of the second cooling die are continuous. The apparatus for producing a folded protein product according to feature 7.

9. The width of the molding passage of the second cooling die is equal to the width of the extrusion passage of the first cooling die. The apparatus for producing a folded protein product according to claim 7 or 8, characterized by the features described above.

10. A manufacturing part for foldable protein products that is attached to an extruder, A first cooling die receives a protein raw material and a liquid raw material that have been kneaded and heated by an extruder, and works in cooperation with the extruder to extrude the protein raw material and the liquid raw material into a strip shape while cooling them, thereby producing a strip-shaped protein product. A second cooling die receives the strip-shaped protein product extruded by the first cooling die and, while cooling the strip-shaped protein product, works in cooperation with the extruder to deform the strip-shaped protein product into a folded shape to produce a folded protein product, Equipped with, The extrusion passage of the first cooling die has a cross-sectional shape in which the height is less than the width, The molding passage of the second cooling die also has a cross-sectional shape in which the height is less than the width. The height of the extrusion passage of the first cooling die is 1.5 mm or more and 10 mm or less. The height of the molding passage of the second cooling die is 2 to 20 times the height of the extrusion molding passage of the first cooling die. The mixing ratio of the protein raw material to the liquid raw material is 1:0.9 to 1:3.

3. A manufacturing component for folded protein products characterized by the following.

11. The extrusion passage of the first cooling die and the molding passage of the second cooling die are continuous. Manufacturing part for a folded protein product according to feature 10.

12. The width of the molding passage of the second cooling die is equal to the width of the extrusion passage of the first cooling die. A manufacturing part for a folded protein product according to claim 10 or 11, characterized by the features described above.

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