KR102838803B1 - Method of isolating soybean protein for preparing high-moisture meat analogues - Google Patents

Abstract

The present invention relates to a method for producing a high-moisture meat substitute having excellent texture without adding wheat gluten, and more specifically, to a method for producing a high-moisture meat substitute, comprising: a first step of immersing soybeans in an extraction solution to produce a soybean protein solution having a solid content of 10 to 30 wt%, a second step of spraying the soybean protein solution into a dryer supplied with gas at 150 to 200°C to produce a soybean protein powder, and a third step of mixing the soybean protein powder with at least one component selected from the group consisting of fat, carbohydrate, dietary fiber, and additives to produce a high-moisture meat substitute raw material powder.

Description

{METHOD OF ISOLATING SOYBEAN PROTEIN FOR PREPARING HIGH-MOISTURE MEAT ANALOGUES}

The present invention relates to a method for producing a high-moisture meat substitute rich in fibrous tissue using only soy protein.

This research was conducted with the support of the High Value-Added Food Technology Development Project of the National Institute of Agricultural Sciences and Technology Planning and Evaluation funded by the Ministry of Agriculture, Food and Rural Affairs (RS-2024-00509810).

This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through High Value-added Food Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (RS-2024-00509810).

As the world economy develops, consumer demand for meat products is increasing. The Food and Agriculture Organization of the United Nations predicts that meat demand will increase by about 70% from the current level by 2050, and as meat production increases, problems such as climate change and environmental pollution are likely to become more serious. In addition, the outbreak of animal-related diseases such as coronavirus, African swine fever, and avian influenza is deepening the supply and demand imbalance of meat products around the world and causing meat product prices to rise. In this situation, as the importance of human health, environmental pollution, and animal welfare is emphasized, interest in alternative meat using plant-based proteins is increasing instead of existing meat products.

High moisture meat analog (HMMA) is a type of meat substitute product that uses plant-based ingredients to replicate the texture and taste of meat. High moisture meat analogs generally have a moisture content of 50% or more and provide a texture and feel similar to meat. High moisture meat analogs can be produced using an extruder to improve texture. This process uses high temperature and pressure to transform plant-based proteins into a layered fibrous structure like meat, which can create a texture similar to real meat. High moisture meat analogs are being developed into various forms of meat substitute products, such as hamburger patties, sausages, and nuggets.

When using only isolated soybean protein in the production of meat substitutes, it is difficult to maintain stable quality in terms of texture, so it is necessary to strengthen the fibrous organization by mixing wheat gluten. Since adding starch to the mixture of wheat gluten and soy protein can further improve the texture, the raw material is usually manufactured using isolated soy protein, wheat gluten, and corn starch in a ratio of 50:40:10. However, wheat gluten is one of the representative allergens, and especially in the West, many people show allergic reactions including indigestion, vomiting, and diarrhea when consuming gluten, and it can cause celiac disease, etc. As a result, interest in gluten-free foods that do not contain gluten is increasing.

Meanwhile, vegetable proteins are classified into four types: water-soluble albumin, salt-soluble globulin, alcohol-soluble gliadin, and acid-soluble glutenin. Soybeans contain about 40% protein, and the proteins contained in soybeans are composed of about 84% globulin, about 4% albumin, about 4% proteose, and about 6% non-protein nitrogen compounds, which shows that most of the proteins that make up soybeans are globulin.

The major proteins in soybeans include 2S, 7S, 11S, and 15S proteins. 2S proteins include Bowman-Birk inhibitor and Kunitz trypsin inhibitor, with a molecular weight of approximately 15 to 20 kDa, accounting for 8 to 10% of the total protein. 2S proteins are relatively small in size and are characterized by acting primarily as protein-decomposing enzyme inhibitors. In addition, they are proteins that can interfere with digestion when humans or animals ingest soybeans. 7S proteins include β-conglycinin, with a molecular weight of approximately 150 to 200 kDa, accounting for 30 to 35% of the total protein. The 7S protein has a trimeric structure of α', α, and β subunits, and specifically consists of an α'-subunit of about 76 kDa, an α-subunit of about 72 kDa, and a β-subunit of about 52 kDa. They have excellent emulsifying properties and foaming abilities, so they are widely used in alternative meat products. They are characterized by relatively low heat stability and sensitivity to pH changes. As for the 11S protein, there is glycinin, and it has a molecular weight of about 300 to 380 kDa, accounting for 35 to 40% of the total protein. The 11S protein has a hexameric structure composed of an acidic α-chain and a basic β-chain, and includes an acidic α-chain of 35 to 50 kDa and a basic β-chain of about 20 kDa. Since it has excellent gel-forming ability, it plays an important role in products such as alternative meat and textured vegetable proteins. It has higher thermal stability than the 7S protein and maintains structural strength even after heat treatment. The 15S protein is mainly a globulin in the form of aggregates, accounting for about 1 to 2% of the total protein. It is formed when the 11S protein aggregates in a high pH environment, and has similar properties to 11S.

In this way, the composition of the storage protein contained in each soybean variety is one of the important factors in determining the processing purpose. Therefore, if a high-moisture meat substitute with a desired texture can be manufactured by controlling the type, content, and ratio of the soybean protein subunit, it will be possible to develop a more economical material while solving the problems of the existing meat substitute containing wheat gluten.

Accordingly, the present researchers, while studying a method for manufacturing a meat substitute without using wheat gluten, completed the present invention by manufacturing a high-moisture meat substitute having properties similar to chicken breast by isolating soybean protein to have a specific protein subunit composition.

Korean Patent Publication No. 10-2023-0153604

The present invention aims to provide a method for producing a high-moisture meat substitute rich in fibrous tissue using only soybean protein.

1. A method for producing a high-moisture meat substitute, comprising: a first step of immersing soybeans in an extraction solution to produce a soybean protein solution having a solid content of 10 to 30 wt%; a second step of spraying the soybean protein solution into a dryer supplied with gas at 150 to 200°C to produce a soybean protein powder; and a third step of mixing the soybean protein powder with at least one component selected from the group consisting of fat, carbohydrate, dietary fiber, and additives to produce a high-moisture meat substitute raw material powder.

2. A method for producing a high-moisture meat substitute, wherein the extraction solution in the above 1 is an acid extraction solution or an alkaline extraction solution.

3. A method for producing a high-moisture meat substitute, wherein the solid content in 1 above contains 30 to 50 wt% of soy protein.

4. A method for producing a high-moisture meat substitute, further comprising the step of degassing and concentrating the soybean protein solution by introducing it into a decompressor in the above 1.

5. A method for producing high-moisture meat substitute in the above 1, wherein the temperature of the gas discharged from the dryer is 70 to 100 ℃.

6. A method for producing a high-moisture meat substitute, wherein the soybean protein powder in the above 1 contains 50 to 70 wt% of protein.

7. A method for producing a high-moisture meat substitute, wherein the first and second steps are performed using an acid extraction solution as an extraction solution in the above 1 to produce an acid extraction soy protein powder, the first and second steps are performed using an alkali extraction solution as an extraction solution to produce an alkali extraction soy protein powder, and the third step is performed using a mixed soy protein powder in which the acid extraction soy protein powder and the alkali extraction soy protein powder are mixed in a weight ratio of 1:2 to 1:6.

8. A method for producing a high-moisture meat substitute, further comprising the steps of: in the above 1, feeding raw material powder into the raw material inlet of an extruder and mixing it with water to produce a first mixture; dissolving a gas-generating powder containing sodium bicarbonate in water and then line-mixing it with the first mixture to produce a second mixture; and generating gas within the second mixture while transporting the second mixture along a first barrel to which steam is supplied.

9. A method for producing a high-moisture meat substitute, wherein in the above 8, the powder for gas generation contains 30 to 40 wt% of sodium bicarbonate, 20 to 30 wt% of disodium pyrophosphate, 10 to 20 wt% of calcium lactate, and 20 to 30 wt% of starch.

10. A method for producing a high-moisture meat substitute in the above 8, wherein the temperature of the second mixture in the first barrel is 25 to 100°C.

11. A method for producing a high-moisture meat substitute, further comprising the step of extruding the second mixture passing through the first barrel in a second barrel at a higher temperature and pressure than the first barrel in the above 8 to produce an extrudate.

12. A method for producing a high-moisture meat substitute in the above 11, wherein the temperature of the second mixture in the second barrel is 110 to 180°C.

13. A method for producing a high-moisture meat substitute, further comprising the step of cooling the extrudate under reduced pressure to a temperature of less than 100° C. in the above 11.

14. A method for producing a high-moisture meat substitute according to the above 1, wherein the high-moisture meat substitute contains 50 to 70 wt% of moisture.

15. A method for producing a high-moisture meat substitute, further comprising a step of sterilizing the raw material powder by contacting it with steam at 150 to 180° C. before producing the first mixture in the above 8.

The present invention provides a method for producing a high-moisture meat substitute having excellent texture without adding wheat gluten.

The high-moisture meat substitute manufactured according to the present invention exhibits a texture similar to chicken breast.

The high-moisture meat substitute manufacturing method of the present invention can use both acid extraction and alkaline extraction methods of protein.

Figure 1 is the definition of the length (L) of the barrel housing and the diameter (D) of the screw.
Figure 2 is the definition of the pitch length (P) of the screw.
Figure 3 is an example of a screw having different pitch lengths and directions.
Figure 4 is a schematic diagram of the extrusion molding machine used in the example.

The present invention provides a method for producing a high-moisture meat substitute having excellent texture without adding wheat gluten.

The present invention provides a method for producing a high-moisture meat substitute, comprising: a first step of immersing soybeans in an extraction solution to produce a soybean protein solution having a solid content of 10 to 30 wt%; a second step of spraying the soybean protein solution into a dryer supplied with gas at 150 to 200°C to produce a soybean protein powder; and a third step of mixing the soybean protein powder with at least one component selected from the group consisting of fat, carbohydrate, dietary fiber, and additives to produce a high-moisture meat substitute raw material powder.

The manufacturing method of the present invention may further include a step of neutralizing the soy protein solution before the second step.

The manufacturing method of the present invention may further include a step of degassing and concentrating the soy protein solution by introducing it into a decompressor before the second step. This step may be performed to control the concentration and viscosity of the soy protein solution. According to this step, the soy protein solution may include, for example, a solid content of 15 to 25 wt%.

The method for producing a high-moisture meat substitute of the present invention can be performed by repeatedly performing the first and second steps using different extraction solvents, and then performing the third step using the mixed soybean protein powder obtained by mixing the resulting soybean protein powders.

The manufacturing method of the present invention may further include a step of charging raw material powder into a raw material inlet of an extruder and mixing it with water to produce a first mixture, a step of dissolving a gas generating powder including sodium bicarbonate in water and then line-mixing it with the first mixture to produce a second mixture, and a step of generating the gas within the second mixture while transporting the second mixture along a first barrel to which steam is supplied.

The manufacturing method of the present invention may further include a step of sterilizing the raw material powder by contacting it with steam at 150 to 180°C before manufacturing the first mixture.

The manufacturing method of the present invention may further include a step of extruding the second mixture passed through the first barrel in a second barrel at a higher temperature and higher pressure than the first barrel to manufacture an extrudate.

The manufacturing method of the present invention may further include a step of cooling the extrudate under reduced pressure to a temperature of less than 100°C in a cooling die.

The manufacturing method of the present invention may further include a step of cooling the extrudate and then storing it in a refrigerator or freezer. Each step is described in detail below.

Preparation of soy protein powder

Soybeans are immersed in an extraction solution to prepare a soybean protein solution having a solid content of 10 to 30 wt%.

In the present invention, the solid content of the soy protein solution may be 10 to 30 wt% or 15 to 25 wt%. The solid content may mean soybeans soaked in the soy protein solution.

In the present invention, if the solid content of the soy protein solution is lower than 10 wt% or higher than 30 wt%, the soy protein solution may not be sprayed smoothly in the second step, and thus may not be properly dried.

In the present invention, the solid content may comprise 30 to 50 wt% of soy protein. For example, the solid content may comprise about 40 wt% of soy protein.

The extraction solution may be either an acid extraction solution or an alkaline extraction solution. As the acid extraction solution, an acid solution commonly used for protein extraction may be used, and for example, an acid extraction solution having a pH of 3 to 5 is preferred. As the alkaline extraction solution, an alkaline solution commonly used for protein extraction may be used, and for example, an alkaline extraction solution having a pH of 7.5 to 9 is preferred.

In one embodiment, the acid extraction solution may be an aqueous HCl solution, and the alkaline extraction solution may be an aqueous NaOH solution.

In the present invention, a soybean protein solution extracted with an acid extraction solution is called an acid extraction soybean protein solution, and a soybean protein solution extracted with an alkali extraction solution is called an alkali extraction soybean protein solution.

When using an acid extraction solution, the soybeans soaked in water can be ground, filtered to obtain soybean milk, and the soybean milk can be immersed in the acid extraction solution to adjust the pH to 3 to 5. The soybean protein can be precipitated by adding an acid solution to the soybean milk to lower the pH to 3 to 5, thereby preparing a soybean protein solution.

When using an alkaline extraction solution, the soybeans soaked in water can be ground, immersed in the alkaline extraction solution to adjust the pH to 7.5 to 9, the solution can be filtered to remove non-protein components, and an acid solution can be added to the filtered solution to adjust the pH to 3 to 5. By adding an acid solution to the filtered solution to lower the pH to 3 to 5, soybean proteins can be precipitated, thereby producing a soybean protein solution.

The manufacturing method of the present invention may further include a step of neutralizing the soy protein solution before the second step. When an acid extraction solution is used as the extraction solvent, the soy protein solution may be neutralized to a neutral pH, for example, pH 7, using an aqueous NaOH solution, and when an alkaline extraction solution is used as the extraction solvent, the soy protein solution may be neutralized to a neutral pH, for example, pH 7, using an aqueous HCl solution.

In the manufacturing method of the present invention, before the second step, the soybean protein solution is introduced into a depressurizer formed with a double jacket structure and concentrated under reduced pressure, thereby controlling the solid content in the soybean protein solution to 15 to 25 wt%.

Reduced pressure concentration can be performed repeatedly to appropriately adjust the solids content for spray drying.

In the present invention, the temperature of the gas supplied to the dryer may be 150°C to 200°C or 160 to 200°C.

In the present invention, the temperature of the gas discharged from the dryer may be 70 to 100°C, 80 to 100°C, or 80 to 90°C.

In the present invention, by maintaining the temperature of the gas supplied to the dryer constant and monitoring the temperature of the gas discharged from the dryer, it is possible to confirm whether the soy protein solution is properly dried.

In the present invention, the spray pressure of the dryer may be 100 to 300 bar, 110 to 290 bar, 120 to 280 bar, 130 to 270 bar, 140 to 260 bar or 150 to 250 bar.

In the present invention, drying by a dryer may be performed for 10 to 30 seconds, 15 to 25 seconds, or 20 seconds.

The final moisture content of the soy protein powder in the present invention may be 2 to 10 wt%, 3 to 9 wt%, 4 to 8 wt% or 5 to 7 wt%. For example, it may be about 5 wt%.

In the present invention, the soy protein powder may contain 50 to 70 wt%, 55 to 70 wt%, 55 to 65 wt%, or 60 to 65 wt% of protein.

In the present invention, the soy protein powder may contain 1 to 7 wt%, 2 to 6 wt%, or 3 to 5 wt% of fat.

In the present invention, the soy protein powder may contain 10 to 35 wt%, 15 to 30 wt%, or 20 to 25 wt% of carbohydrates.

In the present invention, the soy protein powder may contain 1 to 5 wt%, 1.5 to 4.5 wt%, or 2 to 4 wt% of fiber.

In the present invention, the soy protein powder may contain 50 to 70 wt% of protein, 1 to 7 wt% of fat, 10 to 35 wt% of carbohydrate, 1 to 5 wt% of fiber, and 2 to 10 wt% of moisture.

The first to third steps of the present invention may be performed repeatedly or separately as needed. For example, the first and second steps may be performed with an acid extraction solvent, and separately, the first and second steps may be performed with an alkaline extraction solvent, and the third step may be performed with an acid-extracted soybean protein powder obtained by acid extraction and an alkaline-extracted soybean protein powder obtained by alkaline extraction.

In the present invention, an acid-extracted soybean protein powder is prepared by using an acid extraction solution having a pH of 3 to 5 as the extraction solution, and separately, an alkali-extracted soybean protein powder is prepared by using an alkaline extraction solution having a pH of 7.5 to 9 as the extraction solution, and a mixed soybean protein powder can be prepared by mixing the acid-extracted soybean protein powder and the alkali-extracted soybean protein powder in a weight ratio of 1:2 to 1:6, 1:2.5 to 1:5.5, 1:3 to 1:5, or 1:3.5 to 1:4.5.

The manufacturing method of the present invention may be a method of performing the first step by using an acid extraction solution having a pH of 3 to 5 as the extraction solution, separately performing the first step by using an alkali extraction solution having a pH of 7.5 to 9 as the extraction solution, performing the second step to obtain an acid extraction soybean protein powder and an alkali extraction soybean protein powder, and performing the third step with a mixed soybean protein powder in which the acid extraction soybean protein powder and the alkali extraction soybean protein powder are mixed in a weight ratio of 1:2 to 1:6, 1:2.5 to 1:5.5, 1:3 to 1:5, or 1:3.5 to 1:4.5.

Preparation of raw material powder

Raw material powder for manufacturing meat substitutes includes soy protein powder.

The raw material powder for manufacturing alternative meat includes acid-extracted soy protein powder or alkali-extracted soy protein powder.

Soy protein powder is the main ingredient in alternative meat ingredient powder.

In the present invention, the raw material powder may include acid-extracted soybean protein powder and alkali-extracted soybean protein powder in a weight ratio of 1:2 to 1:6, 1:2.5 to 1:5.5, 1:3 to 1:5, or 1:3.5 to 1:4.5.

In one embodiment, the raw material powder may include acid-extracted soy protein powder and alkali-extracted soy protein powder in a weight ratio of 1:4.

In one embodiment, the raw material powder may include soy protein powder in a proportion of 60 to 80 weight percent.

The raw material powder may be manufactured by mixing soy protein powder and at least one ingredient selected from the group consisting of fat, carbohydrate, dietary fiber, and additives.

Fat may be included to mimic the fat content of real meat.

As the fat, one or more oils selected from the group consisting of canola oil, coconut oil, sunflower seed oil, palm oil, cocoa butter, grapeseed oil, avocado oil, olive oil, soybean oil, and flaxseed oil can be used.

In one embodiment, the fat may be canola oil.

Fat may be included in an amount of 4 to 20 weight percent of the raw material powder.

Carbohydrates may be included to provide binding and texture to the product.

As the carbohydrate, one or more selected from the group consisting of corn starch, tapioca starch, potato starch, rice flour, wheat flour, alginic acid, and gellan gum can be used.

Carbohydrates may be included in an amount of 5 to 15 weight percent of the raw material powder.

Unlike other carbohydrates, dietary fiber is not digested and is not used as an energy source in the body. Dietary fiber can be added to meat substitutes to improve texture and maintain moisture.

One or more selected from the group consisting of inulin, indigestible maltodextrin, beta-glucan, cellulose, guar gum, and psyllium husk can be used as dietary fiber.

Dietary fiber may be included in an amount of 5 to 10 weight percent of the raw material powder.

Additives may include binders and emulsifiers, colors, flavors, sweeteners, and flavor enhancers. Additives are included to improve the taste, texture, and shelf life of the meat substitute product, or to mimic its nutritional properties.

As a binder and emulsifier, one or more selected from the group consisting of lecithin (soybean lecithin, etc.), methylcellulose, guar gum, and xanthan gum can be used.

One or more selected from the group consisting of beet juice, carrot extract, annatto and paprika extract may be used as a coloring agent.

Natural fragrances (yeast extract, etc.) and smoke fragrances (smoke fragrance) can be used as fragrances.

One or more sweeteners and flavor enhancers may be used, selected from the group consisting of salt, sugar and yeast extract (MSG substitute).

Additives may be included in an amount of 1 to 10 wt% of the raw material powder.

Sterilization of raw materials

The raw material may contain pathogenic microorganisms such as fungi and bacteria. Before manufacturing the first mixture described below, the raw material powder may be sterilized by contacting it with steam at 150 to 180°C.

Sterilization can be performed in an air-flow powder sterilization device before the raw materials are fed into the raw material inlet of the extruder.

Sterilization can be accomplished by contacting the raw material with steam as it passes through the pipeline together with the steam before being fed into the raw material inlet of the extruder.

The contact time can be controlled by the flow rate of the raw material passing through the heating pipeline. The flow rate of the raw material can vary depending on the amount of steam used, the pressure of the steam, etc. For example, when steam having a temperature of 150 to 180°C is introduced at a pressure of 0.1 to 0.3 MPa in an amount of 80 to 150 kg/h, the contact time (sterilization time) between the raw material and the steam is 0.2 to 1 second.

Preparation of the first mixture

The prepared raw material powder is fed into the raw material inlet of the extruder and mixed with water to produce the first mixture.

The raw material powder may contain 60 to 80 wt% of soy protein powder, 4 to 20 wt% of fat, 5 to 15 wt% of carbohydrate, 5 to 10 wt% of dietary fiber, and 1 to 10 wt% of additives.

The extruder may be provided with a water supply line for supplying water to the charged raw materials. The water supply line may be located at a suitable location for proper mixing of the raw materials.

The first mixture refers to a raw material composition in which water is added to the raw material powder to evenly disperse each component.

Water may be used in an appropriate amount depending on the characteristics of the final product and process conditions. For example, water may be provided in an amount of 200 to 400 parts by weight, or 250 to 350 parts by weight, based on 100 parts by weight of the raw material powder.

After mixing the raw material powder with water, a process of stirring the raw material powder so that it is sufficiently mixed may be further included. The stirring of the raw material powder may be performed in a pipe connecting the raw material inlet of the extruder and the first barrel.

Through this step, the raw material powder is mixed and dispersed with water independently of the powder for gas generation described later.

Preparation of the second mixture

A second mixture is prepared by dissolving a gas generating powder containing sodium bicarbonate in water and then line mixing it with the first mixture.

Sodium bicarbonate comes into contact with water and produces carbon dioxide gas through an acid-base reaction. The produced carbon dioxide creates small bubbles in the first mixture, causing the first composition to swell. In addition, additional carbon dioxide is produced through a heat reaction in the first barrel to which steam is supplied.

The powder for generating gas may contain disodium pyrophosphate as an acid component considering its reactivity with sodium bicarbonate. Disodium pyrophosphate reacts with sodium bicarbonate at an intermediate rate, so that carbon dioxide can be continuously generated from the time the powder for generating gas is mixed with the first mixture until the second mixture is heated and pressurized in the first barrel and the second barrel.

The gas generating powder may further comprise calcium lactate as another acid component. Calcium lactate reacts more slowly with sodium bicarbonate than disodium pyrophosphate. Calcium lactate reacts more slowly with sodium bicarbonate, thereby generating primarily carbon dioxide when the gas generating powder is subjected to heat and pressure in the first barrel and the second barrel within the second mixture.

The powder for generating gas may also contain other acid components such as monocalcium phosphate and potassium bitartrate. These are acid components that react relatively quickly with sodium bicarbonate, which can generate carbon dioxide when mixing the dough. They can quickly release gas at the beginning of mixing, thereby forming volume.

The gas generating powder may include starch (e.g., corn starch) as a filler. The starch stabilizes the sodium bicarbonate and helps the gas generating powder to be evenly mixed with the first mixture.

In one embodiment, the powder for generating gas may be baking powder.

In one embodiment, the powder for generating gas may comprise 30 to 40 wt % sodium bicarbonate, 20 to 30 wt % disodium pyrophosphate, 10 to 20 wt % calcium lactate, and 20 to 30 wt % starch.

In another embodiment, the powder for generating gas may comprise 33 to 37 wt % sodium bicarbonate, 23 to 27 wt % disodium pyrophosphate, 13 to 17 wt % calcium lactate, and 23 to 27 wt % starch.

The powder for generating gas is mixed in water and evenly dispersed in advance, and then line-mixed with the first mixture. The water for dissolving the powder for generating gas can be used in an appropriate amount considering even dispersion with the first mixture. Considering the amount of water included in the first mixture, it can be used in an amount that matches the characteristics of the final product and the process conditions. For example, water can be used so that the concentration of the powder for generating gas is 1 to 10%.

The solution for generating gas is introduced into the first mixture through the pipe, taking into account the flow of the first mixture (main fluid). A fixed structure (e.g. spiral or lattice shape) may be placed inside the pipe to allow natural mixing as the fluid flows.

At this stage, air or steam can be supplied into the pipe as needed, or a screw can be placed to pressurize it.

Gas generation of the second mixture

The manufacturing method of the present invention comprises the step of generating gas within the second mixture while transporting the second mixture along a first barrel through which steam is supplied.

The second mixture is mixed by a screw within the first barrel. If the second mixture is fed directly into the second barrel without passing through the first barrel, the powder for generating gas is not sufficiently mixed with the first mixture, and thus the gas is not evenly generated within the second mixture.

The second mixture can be heated by steam (100° C. steam) inside the first barrel. The temperature of the second mixture inside the first barrel can be from room temperature to 100° C. depending on whether steam is supplied and the amount supplied.

In one embodiment, the temperature of the second mixture within the first barrel can be from 25 to 50 °C, from 25 to 80 °C, from 25 to 100 °C, from 30 to 50 °C, from 30 to 80 °C, from 30 to 100 °C, from 50 to 80 °C or from 50 to 100 °C.

In one embodiment, the temperature of the second mixture when exiting the first barrel may be maintained at 80 to 100° C. If the temperature of the second mixture is less than 80° C., the heat supply required for gas generation may be insufficient, and if it exceeds 100° C., it may be difficult to continuously generate gas until the latter part of the process, thereby reducing the effect of improving the texture of the product and removing the soybean odor.

The first barrel may be composed of one or more barrels in which the temperature and pressure of the steam are independently controlled. The two or more barrels are connected to each other so that the environment required for gas generation can be more delicately created. For example, if the first barrel is composed of three sub-barrels, the temperature of the 1-1 barrel may be set to room temperature, the 1-2 barrel to 80 to 90°C, and the 1-3 barrel to 100°C, so that the second mixture gradually receives more heat.

In this process, the mixing and heating/pressurizing conditions of the second mixture can be changed by adjusting the specifications of the first barrel. The housing length of the barrel, the diameter of the screw, and the pitch length of the screw can affect the mixing and heating/pressurizing of the second mixture.

The definitions of the length (L) of the barrel housing and the diameter (D) of the screw are as shown in Fig. 1. The barrel of Fig. 1 is a barrel equipped with a screw with L/D=4 in one housing.

The pitch length (P) of the screw refers to the length of one revolution of the screw, as shown in Fig. 2. The shorter the pitch length, the higher the pressure applied to the raw material.

In one embodiment, the screw diameter (D _S1 ) of the first barrel may satisfy the relationship between the housing length (L _H1 ) of the first barrel and the following mathematical expression 1:

[Mathematical formula 1]

L _H1 /5 ≤ D _S1 ≤ L _H1 /3.

In mathematical expression 1, the housing length (L _H1 ) of the first barrel means the housing length of one barrel constituting the first barrel. That is, when the first barrel is composed of multiple sub-barrels, it means the housing length of one of the multiple sub-barrels.

In one embodiment, the pitch length (P _S1 ) of the screw of the first barrel may satisfy the following mathematical expression 2:

[Mathematical formula 2]

60 mm ≤ P _S1 ≤ 100 mm.

The screw of the first barrel satisfying mathematical expressions 1 and 2 is advantageous in maintaining the texture of the product and uniformly forming a substitute meat tissue, and is effective in reducing soybean odor.

If the first barrel consists of two or more barrels, the diameter and pitch length of the screw may be different for each sub-barrel within the above range.

Extrusion molding

The manufacturing method of the present invention may include a step of extruding a second mixture passed through a first barrel in a second barrel at a higher temperature and pressure than the first barrel to manufacture an extrudate (wet texturate).

The second mixture is compressed at high temperature in a second barrel to induce protein denaturation and structural changes necessary for organization. As the second mixture goes through this step, the protein molecules are aligned in a high-pressure environment to form a fibrous structure similar to meat, the viscoelasticity of the protein increases, and it is finally formed into the desired size and shape.

The second barrel provides the second mixture with a higher temperature and higher pressure environment than the first barrel. High pressure steam (e.g., steam having a temperature of more than 100° C. and less than 200° C.) is supplied to the second barrel. It is preferable that the temperature of the second mixture in the second barrel be maintained at 110 to 180° C.

The second barrel may consist of one or more barrels, each of which has independently controlled steam temperature and pressure. Two or more barrels may be connected to each other to create a more delicate environment for gas generation.

For example, if the second barrel is composed of three sub-barrels, the temperature of the 2-1 barrel can be set to 120°C, the 2-2 barrel to 140°C, and the 2-3 barrel to 160°C so that the second mixture gradually receives more heat.

For example, when the second barrel is composed of seven sub-barrels, the temperature of the 2-1 barrel and the 2-2 barrel can be set to 110 to 130°C, the temperature of the 2-3 barrel and the 2-4 barrel can be set to 160 to 180°C, and the temperature of the 2-3 to 2-5 barrels can be set to 140 to 150°C, thereby controlling the amount of energy provided to the second mixture.

The second barrel may include a plurality of barrels, each having screws arranged with different pitch lengths and directions (see FIG. 3).

In one embodiment, when the second barrel is composed of three sub-barrels, the pitch length of the 2-1 barrel is set to be relatively long, the pitch length of the 2-2 barrel is set to be shorter than that of the 2-1 barrel, and the pitch length of the 2-3 barrel is set to be shorter than that of the 2-2 barrel, so that the second mixture can be configured to gradually receive a higher pressure.

In one embodiment, when the second barrel is composed of three sub-barrels, the 2-1 barrel sets the pitch direction to the L (left) direction, the 2-2 barrel changes the pitch direction to the R (right) direction, and then the 2-3 barrel sets the pitch direction back to L (left) so that the pressure direction can be set differently.

In one embodiment, the second barrel may consist of a series of 5 to 15 barrels, each supplied with steam independently.

In one embodiment, the screw diameter (D _S2 ) of the second barrel may satisfy the relationship between the housing length (L _H2 ) of the second barrel and the following mathematical expression 3:

[Mathematical Formula 3]

L _H2 /5 ≤ D _S2 ≤ L _H2 /3.

In mathematical expression 3, the housing length (L _H2 ) of the second barrel means the housing length of one barrel constituting the second barrel. That is, when the second barrel is composed of multiple sub-barrels, it means the housing length of one of the multiple sub-barrels.

In one embodiment, the pitch length (P _S2 ) of the screw of the second barrel may satisfy the following mathematical expression 4:

[Mathematical formula 4]

20 mm ≤ P _S2 ≤ 65 mm.

The screw of the second barrel satisfying mathematical expressions 3 and 4 is advantageous in maintaining the texture of the product and uniformly forming a substitute meat tissue, and is effective in reducing soybean odor.

If the second barrel consists of two or more barrels, the diameter and pitch length of the screw may be different for each sub-barrel within the above range.

Cooling and cutting

The manufacturing method of the present invention may further include a step of cooling the extrudate under reduced pressure in a cooling die to a temperature of less than 100° C.

In one embodiment, after the extrusion step, the extrudate is passed out of the extruder through a cooling die while being cooled to a temperature below 100° C. To make the extrudate below the boiling point of water, i.e., below 100° C. under normal conditions, the extrudate is passed out of the extruder through a cooling die. A cooling die known in the art can be used for the extruder.

In one embodiment, the extrudate can be cooled to a temperature in the range of 50 to 90 °C.

As the extrudate passes through the cooling die, its fiber structure created during extrusion is stabilized.

The time for the extrudate to pass through the cooling die can vary depending on the intended use of the substitute meat. The cooling die passage time can be, for example, 30 seconds to 5 minutes.

The meat substitute manufactured according to the method of the present invention can have a protein content of 15 to 30 wt% and a moisture content of 45 to 70 wt%.

Oil may be injected into the cooling die to achieve improved wall sliding and thus easier process control.

The oil can be injected into the extruder mentioned above or into the cooling die. The oil can be injected in a proportion of, for example, 1 to 10%, preferably 2 to 6%, particularly preferably 3 to 4%, based on the total weight of the raw material. The oil can be injected via an additional feed line. For example, an edible oil such as sunflower oil can be used.

Calcium compounds, alginates, or combinations thereof may be additionally injected into the cooling die. The calcium compounds, alginates, or combinations thereof may affect the texture of the meat substitute.

The extrudate that has passed through the cooling die can be cut into desired shapes and sizes and then packaged. The packaged product can be stored refrigerated or frozen.

Hereinafter, the present invention will be described more specifically by examples.

Example

1. Preparation of powder for gas generation

Powder for gas generation was manufactured according to the composition shown in Table 1 below.

division ingredient Manufacturing example 1 Manufacturing example 2 Manufacturing example 3 Powder for gas generation
(weight%) Sodium bicarbonate 35 35 35 Disodium pyrophosphate 25 - 25 Calcium lactate 15 - 10 Monocalcium phosphate - 25 15 Potassium Bitartrate - 15 - Corn starch 25 25 15 total 100 100 100

The above-described manufacturing examples 1 to 3 including sodium bicarbonate can be added as a powder for generating gas, and when such a powder for generating gas is added, an air layer can be appropriately formed between the substitute meat tissues.

2. Preparation of protein powder

Soy protein was isolated from dried soybeans using an acid extraction solution or an alkaline extraction solution.

When using the acid extraction solution, the dried soybeans were washed cleanly and soaked in water for 8 to 12 hours. The soaked soybeans were ground with water using a grinder, and then filtered using a cloth or a strainer to obtain soybean milk. 0.1 N HCl aqueous solution was added to the soybean milk to adjust the pH to 4.5. When the solubility of the protein that reached the isoelectric point decreased and precipitated, the precipitated protein was filtered out and washed several times with distilled water.

When using an alkaline extraction solution, the dried soybeans were thoroughly washed, soaked in water for 8 to 12 hours, and then ground with water using a grinder. Afterwards, 0.1 N NaOH aqueous solution was added to adjust the pH to 8, thereby dissolving the protein well. The solution containing the dissolved protein was filtered to remove soybean residue (non-protein components), and 0.1 N HCl aqueous solution was added to the filtered solution to adjust the pH to 4.5. The precipitated protein was filtered out and washed several times with distilled water.

The precipitated protein obtained by extraction in the above manner was dried to produce soybean protein powder.

For the spray dryer, the inlet temperature, which is the temperature of the gas supplied to the spray dryer, was set to 160 to 200 ℃, the outlet temperature, which is the temperature of the gas discharged from the dryer, was set to 80 to 90 ℃, the spray pressure was set to 150 to 250 bar, and the drying time was set to about 20 seconds. The final moisture content of the dried soybean protein powder was about 5%.

For the drum dryer, the drum surface temperature was set to 150°C to 170°C, the drum rotation speed was 0.5 rpm to 1.0 rpm, and the thickness of the liquid layer to be dried was 0.5 mm to 1.0 mm, so that drying was completed in 7 to 12 seconds. After drying was completed, the drum surface was scraped to obtain a dried product, which was then pulverized to obtain the final soybean protein powder.

By combining the above extraction and drying methods, four types of concentrated soy protein powders (CSP) were prepared as shown in Table 2 below.

Extraction method Drying method CSP 1 Mountain Extraction Spray drying CSP 2 Mountain Extraction Drum drying CSP 3 Alkaline extraction Spray drying CSP 4 Alkaline extraction Drum drying

The concentrated soy protein powder thus obtained is composed of about 60 g to 65 g of protein, about 20 g to 25 g of fat, about 2 g to 4 g of fiber, and about 5 g to 7 g of moisture.

3. Analysis of protein content of protein powder

The protein composition and content of the manufactured concentrated soy protein powder were confirmed. 20 g of concentrated soy protein powder was added with 200 mL of 0.2% NaOH solution, and stirred for 2 hours. After that, the pH was adjusted to 4.5 using 1N HCl solution, and stirred for 30 minutes. The coagulated protein was centrifuged at 8,000 rpm for 10 minutes, and the precipitate was collected, washed with distilled water, and lyophilized to use as a sample. The protein extraction yield was converted using the weight of the lyophilized sample.

To determine the molecular weight distribution of the extracted proteins, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) was performed. Any kD Mini-Protean TGX Precast gel (Bio-Rad, Contra Costa, CA, USA) was used for the gel, and each sample was dispensed onto the gel with a 5-fold concentrated sample buffer (62.5 mM Tris-HCl, pH 6.8, 10% glycerol, 1% LDS, 0.005% bromophenol blue) to a final protein concentration of 3 mg/mL. Electrophoresis was performed at 150 mA for 20 minutes, and after electrophoresis, the gel was stained with Coomassie blue staining solution (Bio-Rad) and then the protein molecular weight distribution of each sample was compared and analyzed (Laemmli, 1970). The molecular weight, classification, and quantitative analysis of the proteins were performed through the molecular weight distribution and the intensity of the band after staining.

As a result of the analysis, the contents of 2S, 7S, 11S and 15S proteins, which are the main proteins of soybeans, were as shown in Table 3 below.

division 2S 7S 11S 15S CSP1 5±2% 70±5% 25±2% - CSP2 4±3% 72±4% 24±2% - CSP3 7±2% 25±3% 65±6% 3±1% CSP4 5±3% 25±4% 67±4% 3±2%

4. Manufacturing high-moisture meat substitutes

High-moisture meat substitute was manufactured according to the device and method shown in Fig. 4. The raw material input amount was 500 kg/h, the screw diameter was 62 mm, and the rotation speed was set to 550 rpm. The screw diameter of the twin-screw extruder was 62 mm, and the ratio of the screw diameter to the housing length (L/D ratio) was 40:1. The cooling temperature of the cooling die was 70℃. The temperature of each barrel was controlled using a heater and cooling water.

Specifically, raw material powder was fed into the raw material inlet (hopper) of a twin-screw extruder and mixed with water to prepare a raw material composition (first mixture).

In addition, separately, the powder for generating gas (baking powder) was each dissolved in water (5% aqueous solution) and introduced into the line through which the raw material composition (first mixture) passed, and after being uniformly mixed within the line, the raw material composition (second mixture) in which the solution for generating gas was evenly dispersed in the first mixture was passed through a 1-1 barrel set to room temperature and then heated and mixed in a 1-2 barrel set to a temperature of 80-100°C.

The contents of each component in the second mixture injected into the first barrel are as shown in Table 4 below.

Raw material name Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Purified water 68.5 % 68.5 % 68.5 % 68.5 % 68.5 % 68.5 % CSP1 25 % - - - 5 % - CSP2 - 25 % - - - 8 % CSP3 - - 25 % - 20 % - CSP4 - - - 25 % - 17 % Dietary fiber 2.5 % 2.5 % 2.5 % 2.5 % 2.5 % 2.5 % Canola oil 1.50 % 1.50 % 1.50 % 1.50 % 1.50 % 1.50 % Seasoning 1.50 % 1.50 % 1.50 % 1.50 % 1.50 % 1.50 % Baking powder 1.00 % 1.00 % 1.00 % 1.00 % 1.00 % 1.00 % total 100.00 % 100.00 % 100.00 % 100.00 % 100.00 % 100.00 %

Thereafter, the second mixture was extruded in barrels 2-1 to 2-7 at 110 to 165°C to obtain a high-moisture meat substitute having a moisture content of 70%. The manufactured meat substitute was vacuum-cooled and then stored frozen at -20°C.

5. Analysis of physical properties of the examples

(1) Texture Profile Analysis (TPA) analysis

Hardness, springiness, cohensiveness, chewiness, and cutting strength of Examples 1 to 6 were measured. Samples of the high-moisture meat substitutes of Examples 1 to 6, each cut into a size of 10×20×20 mm, were used. The high-moisture meat substitutes were thawed in a refrigerator (10°C) 24 hours before measurement, and then left at room temperature for 2 hours before measurement.

Hardness is the maximum force resisted by the sample during the first compression cycle. Elasticity, cohesiveness, chewing strength and breaking strength are defined by the following mathematical equations 5 to 8 as suggested by Trinh and Glasgow (2012):

[Mathematical Formula 5]

(D1: distance at which the first maximum stress occurs, D2: distance at which the second maximum stress occurs),

[Mathematical Formula 6]

(A1: first maximum stress area, A2: second maximum stress area),

[Mathematical formula 7]

,

[Mathematical formula 8]

.

Elasticity, cohesiveness, and chewiness were measured according to the conditions in Table 5 below, and cutting strength was measured using a cutting probe (knife blade). A total of 10 measurements were made, and the average value was calculated by excluding the maximum and minimum values.

T.A. XT. Plus Texture Analyzer (Stable Micro Systems Ltd., UK) Caption Units Value HMMA Pre-Test speed mm/s 1.00 Test speed mm/s 2.00 Post-Test speed mm/s 5.00 Target Mode Strain 60.0% Time sec 5.00 Trigger Type Strain Trigger Force g 5.0 Advanced Options Off Probe P/100

(2) Measurement of texturization degree (DT)

The degree of organization of the high-moisture meat substitutes of Examples 1 to 6 was calculated by applying the method of Fang et al. (2014) as shown in the following mathematical formula 9 as the ratio of the cutting strength of transversal direction (F _T ) to the cutting strength of longitudinal direction (F _L ):

[Mathematical formula 9]

(F _T : vertical cutting strength, F _L : flow direction cutting strength).

The degree of organization was measured according to the conditions in Table 6 below, and a total of 10 measurements were taken, excluding the maximum and minimum values, to calculate the average value.

T.A. XT. Plus Texture Analyzer (Stable Micro Systems Ltd., UK) Caption Units Value HMMA Test Mode Compression Pre-Test speed mm/s 1.00 Test speed mm/s 0.50 Post-Test speed mm/s 10.00 Target Mode Distance 15 mm Trigger Type Strain Trigger Force g 20.0 Advanced Options Off Probe Knife blade

(3) Measurement data

The physical properties of Examples 1 to 6 measured according to the above method are shown in Table 7 below.

division Hardness (N) Elasticity
(%) Cohesion
(%) Chewing
(N) Breaking strength (g/cm) ² ) Organizational chart F _T (perpendicular) F _L (flow) Example 1 12500 95 65 7700 18600 16000 1.16 Example 2 13500 80 50 5400 20100 17000 1.18 Example 3 26000 65 35 6000 38000 28500 1.33 Example 4 28000 50 30 4200 42000 29500 1.42 Example 5 21000 88 50 9240 31000 21500 1.44 Example 6 19200 86±0.8 55±1.2 9081 32300 23200 1.39 Comparative Example 1 22600 90±0.8 45 9153 29900 21600 1.38

For Comparative Example 1, boiled chicken breast was used. As a result of TPA and DT analysis, in the case of Example 1, the proportion of 7S native type protein was the highest, so elasticity and cohesion were very excellent. In the case of Example 2, the protein composition was almost similar to Example 1, but elasticity was slightly lower and strength was slightly higher due to thermal denaturation during the drying process.

In the case of Example 3, it is a high-moisture meat substitute containing 11S protein as the main protein, and is characterized by higher strength and lower elasticity compared to Example 1. In the case of Example 4, the protein composition is similar to Example 3, and the strength was the highest.

For Examples 5 and 6, it was confirmed that they had very similar properties to Comparative Example 1 (boiled chicken breast) in terms of elasticity, cohesiveness, chewiness, cutting strength, and texturization. When evaluated overall, Examples 5 and 6 had the best properties.

Claims (15)

A first step of preparing a soybean protein solution having a solid content of 10 to 30 wt% by immersing soybeans in an extraction solution;
A second step of producing soy protein powder by spraying the soy protein solution into a dryer supplied with gas at 150 to 200°C, and
A third step of producing a high-moisture meat substitute raw material powder by mixing the above soy protein powder with at least one ingredient selected from the group consisting of fat, carbohydrate, dietary fiber and additives,
The acid extraction solution is used to perform the first step and the second step to prepare an acid extraction soy protein powder,
The first step and the second step are performed using an alkaline extraction solution as the above extraction solution to produce an alkaline extraction soybean protein powder,
A method for producing a high-moisture meat substitute raw material powder, wherein the third step is performed using a mixed soy protein powder obtained by mixing the acid-extracted soy protein powder and the alkali-extracted soy protein powder in a weight ratio of 1:2 to 1:6. delete A method for producing a high-moisture meat substitute raw material powder according to claim 1, wherein the solid content contains 30 to 50 wt% of soybean protein. A method for producing a high-moisture meat substitute raw material powder according to claim 1, further comprising the step of degassing and concentrating the soybean protein solution by introducing it into a decompressor. A method for producing high-moisture meat substitute raw material powder according to claim 1, wherein the temperature of the gas discharged from the dryer is 70 to 100°C. A method for producing a high-moisture meat substitute raw material powder according to claim 1, wherein the soybean protein powder contains 50 to 70 wt% of protein. delete A step of introducing a high-moisture meat substitute raw material powder manufactured according to any one of the methods of claims 1 and 3 to 6 into a raw material inlet of an extruder and mixing it with water to manufacture a first mixture;
A step of preparing a second mixture by dissolving a powder for generating gas containing sodium bicarbonate in water and then mixing it with the first mixture through a line, and
A method for producing a high-moisture meat substitute, comprising the step of generating the gas within the second mixture while transporting the second mixture along a first barrel supplied with steam. A method for producing a high-moisture meat substitute according to claim 8, wherein the powder for gas generation contains 30 to 40 wt% of sodium bicarbonate, 20 to 30 wt% of disodium pyrophosphate, 10 to 20 wt% of calcium lactate, and 20 to 30 wt% of starch.
A method for producing a high-moisture meat substitute according to claim 8, wherein the temperature of the second mixture in the first barrel is 25 to 100° C.
A method for producing a high-moisture meat substitute according to claim 8, further comprising the step of extruding the second mixture passed through the first barrel in a second barrel at a higher temperature and higher pressure than the first barrel to produce an extrudate.
A method for producing a high-moisture meat substitute according to claim 11, wherein the temperature of the second mixture in the second barrel is 110 to 180° C.
A method for producing a high-moisture meat substitute according to claim 11, further comprising the step of cooling the extrudate under reduced pressure to a temperature of less than 100° C. in a cooling die.
A method for producing a high-moisture substitute meat raw material powder according to claim 1, wherein the high-moisture substitute meat contains 50 to 70 wt% of moisture. A method for producing a high-moisture meat substitute according to claim 8, further comprising a step of sterilizing the raw material powder by contacting it with steam at 150 to 180° C. prior to producing the first mixture.