KR800001609B1 - Process for preparing fibrous proteir material - Google Patents

Abstract

Fibrous protein product having fish muscle-like texture is prepd. by freezing after soaking 600 g of soybeans in water and grinding in 10 vols of boiling water. the slurry was boiled for 15 min and filtered and the filterate aws adjusted to pH 7.5, and mixed with 0.02% antioxidant. The mixt. was placed in a flat container in a layer 1-in. deep and frozen with dry ice and liq. N. The frozen material was stirred in 95% EtOH at -5 to -100C for 8 hrs. The stabilized protein was dewatered by pressing vertically to the direction of fiber orientation and dried to obtain a product.

Description

Method for producing fibrous protein bodies

The present invention relates to a method for producing a tissue protein. More specifically, the present invention relates to a novel method for preparing tissue proteins that can be used as or in the manufacture of fish analogs.

In recent years, considerable research efforts have been focused on the development of new technologies for producing meat protein containing foods from various vegetable and animal protein sources. This was a major impetus in economic terms. It is clearly advantageous that the animal replaces the plant protein containing protein more efficiently, at least in part, rather than inefficiently by converting the protein-containing vegetable material into meat. This is especially true if population growth is far ahead of the availability of pastures for livestock. In recent years, efforts have also been made to avoid certain natural products that are not good for religious, racial or health reasons.

All natural meats, including fish and poultry, have a fibrous structure. The organization of meat products is inherently dependent on the properties of meat fiber. Likewise, the presence of a fibrous structure is an important factor in tissue meat products. Thus, in the manufacture of these artificial products, for example meat analogues, much effort has been made to produce a fibrous structure similar to natural meat. Many researchers have developed a variety of techniques for obtaining fibrous structures, and a large number of literature on the preparation of meat analogs with fibrous structures are available.

An early researcher, Boyer, described in US Pat. No. 2,682,466 a method for preparing artificial meat products containing large amounts of vegetable protein filaments. This protein filament is a colloidal protein dispersion that is pressed into a coagulation bath through a porous membrane, such as a spinneret, to precipitate the protein in a filamentous state. The filaments are organized into artificial meat products by using binding materials, including grains and proteins. Spun vegetable fibers can be used to form highly ordered fibrous structures. Unfortunately, the production of spun fibers is complex and has a relatively high manufacturing cost. In addition, spun vegetable proteins generally lack nutrients because their raw materials depend on soy isolates.

In view of the challenges inherent in spinning fiber technology, other researchers have been encouraged to explore alternatives to the technology. The alternative described in US Pat. No. 3,488,770 describes the preparation of an artificial meat product which contains a protein that is longer than the width of the cell and whose structure is an open structure in which the cells are substantially aligned in a row. This product is made by expanding the dough by substantially extruding the dough into a reduced pressure zone. Another alternative to making dough is described in US Pat. No. 3,693,533. According to this method, the protein containing the dough is coagulated while passing through a set of converging conveyors. Stretching during solidification produces unidirectional fibers. These methods may be less expensive to manufacture than spinning fiber technology, but the quality of the fibers produced is poor.

Japanese Patent Publication Nos. 48-21,502 and 48-34,228, and US Pat. Nos. 3,870,808 and 3,920,853 disclose methods for freezing protein solutions or dispersions and heating the frozen masses to fix proteins. The method for producing fibrous protein aggregates is described. These fibrous products have been described as meat. However, even taking the best of these methods, no technique has yet been developed to approximate the fibrous forms commonly found in fish meat such as tuna. The fish fiber is well-organized, but is generally flaky. This type of tissue is extremely desirable when it is desired to obtain analogs of natural fish meat.

In view of the difficulties of the prior art, it is beneficial to develop a method for producing a tissue protein having a well-defined contour that combines nutrition and economics and having fish-like fibrous tissue.

Thus, the method of the present invention freezes the mixed aqueous solution of thermocoagulated protein by cooling in a manner and proportion that is efficient to produce elongated ice crystals that are normally vertically aligned with respect to the cooling surface, and freezing perpendicular to the ice crystals. Treating the frozen mass at a temperature substantially different from the temperature of the frozen mass to generate temperature stress in the fragile line in the mass, and efficiently stabilizing the protein in the frozen mass to prevent the loss of the fibrous structure during heating. The protein is stabilized by heating to stabilize the protein.

According to the present invention, various fish meat tissues can be obtained using a plurality of protein bodies. A common characteristic of all these products is the presence of well-defined and ordered fibers separated by dividing lines which are generally perpendicular to the direction of the fiber arrangement. These fibers are made from vegetable or animal proteins, which are used alone or in mixtures. In this way, tissue proteins having desired properties can be prepared by easily balancing the structure, taste, and nutritional properties of the fibers. Among these characteristics, the important thing in the present invention is the necessity of cooling in a direction and a ratio effective in obtaining clear and ordered ice crystals, the necessity of an impact temperature stress generating step to make a dividing line perpendicular to the fiber orientation, And there is a need to stabilize the protein before heat treatment.

Any edible protein or mixture of proteins may be used in the method of the invention, but in the case of a single protein or mixture, at least one or more of the proteins must be soluble or partially soluble and will be stabilized by the treatment according to the invention. It should be possible. In general, proteins with good solubility provide good and unique fibrous structures because ice crystals can grow freely and are not limited by undissolved solids. However, using a protein solution containing a significant amount of insoluble matter such as soy flour, meat homogenates and fish homogenates, good results can be obtained in forming the fiber structure according to the present invention. Representative examples of protein bodies that can be used to achieve good results in accordance with the present invention include soybean milk, soybean isolates, whole milk, meat slurries, fish slurry, gluten, soy flour, wheat protein concentrates, whey ), Egg protein, blood protein, and single cell protein.

The final structure of the product depends in part on the additives used, such as protein sources, seasonings, fillers, fats, carbohydrates, salts, and the like. For example, products made from soybean milk have a fresh, soft and soft structure with good fiber tension. Soy milk produces products with the desired softness, presumably due to the oil emulsified in the protein. Soy flour, on the other hand, forms products with lower tensile strength than soybean milk, but this type of flexibility is desirable for several products alone or in admixture with other protein bodies.

A protein is mixed with water to form an aqueous protein mixed solution, even if it is from any source, at least some of the protein is dissolved in water. The aqueous solution of the protein mixture is characterized as a solution, dispersion or suspension of the protein with water. Because of the different forms of the protein, the pH of the mixture can be adjusted to increase the solubility of the changing protein. In order to obtain the optimum tensile strength and fidelity of the fiber, it is usually preferable to adjust the pH of the aqueous protein mixture solution to the maximum protein solubility. The pH value of the mixture appears to directly affect the tensile strength of the final tissue product. Some protein materials, such as soy flour, exhibit good structure and tensile strength at higher pHs, such as pH 10. This is probably because these proteins are more soluble at higher pH and are partially separated and denatured by alkaline conditions prior to organization. Protein molecules tend to unfold at high pH, forming more complete fibers. Some proteins, such as egg whites, have good solubility at their original pH and do not need to adjust their pH to alkaline conditions.

While high pH is sometimes useful for the manufacture of tissue products, high pH is generally an undesirable exception. The pH of the final product can be lowered during the rehydration period using acid in the rehydration bath, which will be described later in detail. However, often, lowering the pH of a tissue product to a level below the value specified for a particular protein will affect the structure of the product. Depending on the particular particular end use, this tissue effect may or may not be desirable. For proteins that dissolve at their original pH 6-8, neutralization will not be necessary.

The aqueous solution of the protein mixture can be easily obtained by mixing the water of the protein. If necessary, the protein body may be finely divided or ground before and after mixing with water, and the pH may be adjusted to obtain optimum solubility. The presence of soluble and insoluble incoagulant materials can be tolerated, and in fact is preferred in some cases as long as it does not adversely affect the desired quality of the fiber structure for use in a particular application. In some cases, it is undesirable if the fiber's stretchability is reduced due to the presence of excess fat. In other cases, however, the lowering of the tensile strength is desirable since it gives the product a more flexible structure. Therefore, additives conventionally used in the manufacture of fibrous artificial meat products can be used by the present invention, which provides a process that can vary widely the compositional properties of fiber formers, thereby providing nutrition of tissue state from a single basic process. It is achieved by the present invention to obtain this rich variant. It is another advantage of the present invention that relatively high amounts of fat can be used to obtain good fibrous tissue.

The concentration of solids in the mixture can affect both the organization of the product and the efficiency of the process. It is generally desirable to keep the concentration of solids low. One reason is that increasing the concentration of solids tends to shrink unique fiber structures. Typically, the content of solids is suitably less than about 40%, preferably about 3%, based on the weight of the mixture. As the concentration of solids increases, the efficiency of stabilization decreases. However, treatment at too low a concentration results in an economic loss since the cost of water removal is increased. The costs of energy, vessels, transport and storage facilities increase rapidly as concentrations decrease. However, the quality of the fibers produced at low concentrations is high. Therefore, it is necessary to understand the various factors to be considered and to determine the concentration that is most suitable for each particular system. In the broadest sense, the most suitable concentration for freezing is a protein concentration of 3 to about 35%, suitably 10 to 30, based on the total weight of the aqueous protein mixture solution. However, the optimal concentration of certain proteins and additives can vary widely within this range, and sometimes beyond this range.

Experts in the art will be able to determine the optimum conditions for the particular system employed, with knowledge of the economics of their particular process equipment and methods. Persons skilled in the art will be aware of embodiments of many different systems by the embodiments described below. Substantially unique, effective concentrations for producing oriented fibers are acceptable in the present invention. Specific concentrations should be determined on a case-by-case basis to balance any suitable product properties with process efficiency. It should be noted that the gelled protein material in the form used to prepare the tofu, wherein the gel structure limits the use of water to form long crystal structures, cannot be used in accordance with the present invention.

Once prepared, the aqueous solution of the protein mixture is frozen according to a certain orientation pattern, so that the outline produced by the ice crystals is clear and an orderly fibrous structure is formed. As the water freezes to form ice crystals, the remaining protein mixture is more concentrated. Once the ice crystals are formed, the protein bodies are separated into distinctly, generally parallel, aligned zones. Any means that can achieve this result is suitable for the present invention. Ice crystals form a plaid protein form in the fibrous part regularly between long ice crystals. The protein zones are almost completely separated from each other, forming substantially independent protein fibers upon solidification. However, the bands of proteins are not completely independent of each other, but bind at sufficient positions to form a branched or crosslinked structure. The bond achieved is sufficient to provide cohesiveness to the finished product similar to cooked meat, and does not substantially destroy its own fiber structure. This binding force achieved during fiber formation does not exclude the need for binder addition.

Freezing can be performed by cooling at least one side, suitably one side or two opposite sides of the mixture below the freezing point of the mixture. Cooling or freezing causes freezing to occur throughout the thickness of the mass to produce generally parallel fibers, usually aligned perpendicular to the cooling surface. Preferably, the cooling surfaces should be flat, but they may have other arrangements, ie regular or irregular arrangements. For example, a single cooling surface having a hemispherical, spherical or cylindrical arrangement may be used in contact with an aqueous solution of the protein mixture. In these examples, the ice crystals and protein fibers are radially formed toward the central portion perpendicular to the tangential direction with respect to the surface. During freezing a boundary line appears between the freezing mixture and the liquid mixture, which moves in the cooling direction. At representative freezing temperatures used by the present invention, and where the cooling surface is not very irregular, this boundary will generally match the shape of the cooling surface of the protein mixture. However, under other conditions according to the invention, this boundary will have a slightly modified form. After the initial thickness of the mixture is frozen, it is to be understood that the moving freezing boundary becomes the cooling surface, through which heat transfer takes place. This is the moving boundary, which in turn controls the manner of ice crystal formation, and thus the fibers. In all cases, an important consideration is the production of well-defined contoured fibers with an ordered arrangement similar to natural meat. If desired, the surfaces of the aggregates that are not in contact with the cooling source can be insulated to reduce heat transfer to these surfaces. In most cases it is observed that the surfaces not in contact with one or both cooling surfaces exhibit the thickness of the fibers oriented slightly disorderly. The reason is that it is difficult to obtain directional cooling at these edges due to heat transfer with external sources. This edge can be retained in the final product or can be separated by cutting with a knife, heating wire, or the like. It should also be noted that when the opposing surface is cooled, discontinuous horizontal surfaces appear to bisec the thickness of the frozen mass. This is apparently due to the independent crystal growth from each surface facing each other towards the contact surface in the center of the mass.

According to the invention a number of cooling sources can be used. For example, an aqueous solution of the protein mixture is simply placed in a pot and placed in a dry ice piece or immersed slightly deep (eg 1/8 inch; 0.32 cm) in a cooling liquid such as liquid nitrogen, ethylene glycol, brine or the like. Alternatively, a container of an aqueous solution of the protein mixture may be placed on the plate freezers or between plate freezers facing each other. Also suitable are moving belt type freezers of the type described in US Pat. Nos. 3,253,420 and 3,606,763. The temperature used may be any temperature that is substantially effective for producing each aligned ice crystal. It should be noted that the cooling rate is clearly contoured, orderly, and not a common factor associated with the formation of long fibers when cooling occurs in substantially the same direction, but the cooling rate clearly affects the size and shape of the crystals. do. Rapid cooling quench forms extremely fine ice crystals. Lower cooling or freezing rates form long needle ice crystals. Preferred cooling rates are defined by the forward rate term of the freezing boundary, from about 0.02 to about 1.0 ft / hr. (About 0.61 to 30.5 cmhr). More suitably between about 0.03 and about 0.5 ft / hr. (About 91.4 to 15.2 cm / hr.).

At the present time it is not believed that the temperature of the protein solution or slurry prior to the freezing step is important, but it is considered suitable to lower the temperature of the solution or slurry to as close to the freezing point as possible before freezing. At present, it is appropriate to focus only on economic matters. It is more inexpensive to cool the liquid by stirring or highly surface contacting the liquid with the heat transfer medium in accordance with conventional practice, rather than by means of a single or two opposing heat transfer elements used for freezing. However, it should be noted that the liquid mixture should not be subcooled prior to the freezing operation, because the subcooling results in too fast and disordered cooling resulting in undesirable and disordered fibrous structures in the product.

When this frozen body is actually immersed in a liquid such as liquid nitrogen at a lower temperature than this, it is unexpected that a split plane is formed perpendicular to the fiber forming direction. Similar effects were observed when the frozen body was actually immersed in a hot liquid. After the protein is stabilized and heated as described below, the product is rehydrated to surprisingly obtain a fish-like structure. While not wishing to be bound by any theory, the formal explanation that occurs during this process is based on how the material reacts during freezing. During unidirectional freezing, concentration gradients of dissolved solids (eg salts, amino acids, polypeptides, etc.) occur along the fiber axis. This gradient occurs repeatedly when the front of the ice crystal moves upward and separates. As a result, the high and low concentrations of solids are in the band perpendicular to the fiber axis. Then, when the freezing body is actually immersed in a warm or cold bath (e.g. liquid N ₂ ), the ice crystals expand along the fiber axis, causing the fibers to split along the weak plane. You get a structure similar to meat. In typical cases where the minimum size of the frozen aggregates is about 2 inches (about 5.1 cm), the immersion temperature is suitably cooled or warmed by at least 50 ° C. more preferably than the frozen aggregates, particularly at least about 100 ° C .. In the case where the minimum size is large, the temperature difference must be so large, and in the case where the minimum size is small, the temperature difference must be so small.

After freezing and after impact temperature treatment as described above, the crystal structure of the material can be easily observed, and if necessary, the frozen mass can be broken up and visually observed. To maintain the integrity of each protein fiber thus formed, the protein may be lyophilized or immersed in frozen solution in an aqueous solution containing an soluble soluble substance capable of lowering the freezing point of water and stabilizing the protein by the present invention. Stabilize. If the protein, which is actually soluble, is not stabilized prior to the heating step, such as heat treatment, the heating causes the individual fibers to bind too much due to the melting point of the individual crystals and the ice crystal lattice. Then, when the fibers are heat treated, they tend to form less pronounced fibrous aggregates. Especially for artificial fish meat, excessive binding of protein bodies is undesirable. Also in this respect, frozen frozen masses should not be stored at slightly lower temperatures for long periods of freezing. Storage under these conditions causes the ice to recrystallize and form a disordered fibrous structure.

This is to some extent desirable as a means of influencing the structure of the final artificial fish meat, but it should be done knowing that reorientation occurs and only to the extent desired for the particular application.

Lyophilized bodies can be lyophilized according to conventional methods using commercially available devices. The product can be subdivided before and after lyophilization. The moisture content should be reduced to a point where the structure does not collapse and should be sufficiently dried. Details of lyophilization are well known to those skilled in the art and are not within the scope of the present invention. As a representative lyophilization, a laboratory freeze dryer can be used to freeze 1 inch (2.54 cm) thick plate with a total volume of 3 liters.

Dry for about 2 days to reduce the moisture content to about 3-5%. In this particular device, the temperature of the plate is about 30-30 ° C., preferably about 25 ° C., the temperature of the condenser is about −40 ° -70 ° C., preferably about −50 ° C., and the pressure in the freeze-drying chamber is mercury. (Hg) about 20-50 microns, preferably about 30-40 microns. These set of conditions are merely examples of conditions that can be used and do not limit the invention. The fibers can be dried in a self-sustaining form, preferably up to a moisture content of about 10% or less, but the actual melting of the ice crystals prevents the fibers from excessively binding and the temperature is too high during the period when the fibrous structure is disordered. Freeze-drying methods that keep to prevent are effective and suitable for the present invention.

As an alternative method, the frozen mass can be immersed in the stabilizing solution according to the conventional method using a commercial apparatus. The product can be subdivided before and after dipping. Precipitate proteins using organic solvents that can be miscible with water, some of these known substances lowering the hydrophilic potential of proteins by causing them to degrade the usefulness of water to the protein and to cause structural changes in the protein. As long as the freezing point of water is lowered and the surface tension of water is lowered, it can be used as a stabilizing material in an aqueous solution. The amount of water useful for the protein can be reduced simply by reducing the mole fraction of water in the presence of these stabilizers. Thus, water is less useful for dissolving proteins. In addition, the effective stabilizer shifts the equilibrium state to the right as follows, thereby adversely affecting the solubility of the protein.

The most effective stabilizers that can be used reduce the surface tension of water, thus reducing the contribution of water to the binding of hydrophobic groups of the protein. The most remarkable binding and desorption effect in lowering the solubility of proteins is known in the case of organic solvents in which molecules have short chain-side chain hydrophobic groups. The freezing point of the water is important because the stabilizer must be able to penetrate the ice in the frozen product mass.

Examples of suitable stabilizers include polar organic solvents such as alcohols, of which ethanol and propanol are suitable. The reason is that even if the residual amounts of these solvents are present in the product in relatively large amounts, they are not toxic. Although ethanol is particularly suitable, any solvent may be used as long as it has a desired function and after removal of the solvent by conventional methods such as extraction and drying, and there is no toxicity at a suitable level remaining in the product. Also suitable as stabilizers or coagulants are known acids and salts having the necessary functions in aqueous solution. If desired, these known salts or acids can be used in admixture with alcohols such as ethanol, or other non-toxic organic solvents. Such mixing is desirable in view of balancing the benefits and purposes of various stabilizers for a particular process or product use. Suitable acids include hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid and other edible acids. Suitable salts include edible ammonium salts, alkali metal salts and alkaline earth salts of these acids and other salts having a desired function.

Ethanol, the only example of a suitable stabilizer that can be used according to the invention, will be used as a stabilizer in the following brief description.

When the frozen aggregate of the protein and ice prepared by the above-mentioned method is contacted with ethyl alcohol in a coagulation bath, diffusion exchange occurs between the two phases, ie, water exchange between water and ethyl alcohol in the protein and ice crystals. Ice crystal melts and water are removed, but alcohol enters the protein body. As soon as the protein comes in contact with alcohol, the fiber becomes insoluble. To make the protein completely insoluble, alcohol must be completely penetrated into the protein body. After sufficient time has elapsed, no further change occurs. Thus, a state of parallelism is achieved between the two phases. The final equilibrium concentration of alcohol in the coagulation bath depends on the ratio of alcohol to water in the frozen protein aggregates. Since the concentration of alcohol in this coagulation bath affects the freezing point of the solution and the diffusion and coagulation rate of the protein, this is an important factor to control in this process.

When protein aggregates frozen in the same direction are immersed in the alcohol bath to stabilize the crystallized fibrous structure, the temperature of the alcohol bath should be lower than the freezing point of the protein solution. This freezes the free water, minimizing the rehydration of the protein by water and the degradation of the frozen aligned structure. At the freezing point, water is present as ice crystals in the protein aggregates. When the ice crystals come in contact with alcohol, the ice melts and the water is waterproof, while at the same time the protein also comes in contact with a sufficient concentration of alcohol and becomes insoluble. If the temperature of the alcohol bath is above -5 ° C and close to the freezing point of water, recrystallization occurs in the frozen protein body so that the fiber structure in the same direction disappears and a disordered structure is formed.

The freezing point drop depends on the concentration of the solute added in the solution. Therefore, the freezing point of the coagulation bath can be adjusted by changing the concentration of alcohol. To prevent freezing of the alcohol bath, the freezing point should be lower than the treatment temperature.

An effective concentration of stabilizer may be used optionally, but in the case of ethanol this concentration should be at least about 10%, preferably at least 20%. In certain cases using 5% ethanol, the protein was completely dissolved and the fibrous structure was degraded. At 10%, the protein was partially dissolved and the fibers were very soft. However, the fibers did not fall off. At 20% alcohol, the protein did not dissolve. The structure was soft because of partial hydration. At alcohol concentrations above 30%, the protein was completely insoluble and the structure of the fibrous material was rigid. The final equilibrium concentration of alcohol was more than 70% during this coagulation process, and the fiber easily crumbled due to excess dehydration of the protein. It was found that the optimal concentration at equilibrium was about 60% ethyl alcohol.

During this process, ethanol soluble pigments, carbohydrates and fats and oils in the protein body are removed. This is preferable from the viewpoint of removing the pigment and air bubbles from the product. Fats and oils can be recovered and used in food.

Once stabilized by lyophilization or dipping, as described above, the fibrous aggregates can be dried and stored for an indefinite period and then heat treated or immediately heat treated for later use. Certain types of heat treatment can then be stored for later use. By appropriately selecting a particular type of heat treatment, the final product structure, color, brashness, tensile strength, rehydration and moisturization can be achieved. Tissues subjected to severe heat treatment tend to have less moisture after rehydration. However, it is preferred that all tissues according to the invention undergo heat treatment in an amount sufficient to increase the integrity of the fibrous structure. Mild heat treated materials are softer and tend to be more flexible than severe heat treated materials. Wet heat treatment is very effective and gives the final product a very good flesh texture.

The amount of heat treatment performed with or without pressurization to stabilize the product depends on the type of protein body used. For example, the dried soybean milk fiber may be heat treated in an autoclave at 15 psig pressure for about 5 to 10 minutes to stabilize the structure, while the soy flour fiber may be heat treated for about 20 to 25 minutes under the same conditions. Combinations of time, temperature and pressure that are effective for heat treating the protein to be substantially independent fibers can be used.

Heat treatment for about 5-30 minutes at a temperature between about 100 ° -120 ° C. seems to be suitable for the structure required in the final product. The exact time, temperature and pressure used can be easily measured by experts in this technology for various products. Various specific heat treatment operations are described in the Examples described below.

Typical examples of heating means that can be used include conventional autoclaves or steam chamber devices capable of producing pressures up to about 20 psig and temperatures up to about 130 ° C. Moreover, as a suitable thing, the infrared heater which uses the electric or gas fuel which can operate on the conditions of high relative humidity is mentioned. The use of wet heat treatment in these apparatuses, autoclaves or steam chambers results in more complete solidification or fixation of the protein body. The specific heating means used is not critical to the invention. What is needed is heating to sufficient time and strength to sufficiently solidify or fix the protein to substantially prevent the loss of the individual protein fibers after rehydration.

After the heat treatment, the fibrous protein body can be marketed as it is or can be immediately rehydrated to obtain more fleshy tissue. The product can be easily rehydrated by soaking in water for a sufficient time to obtain the desired moisture content. The rehydration solution may contain acids or flavoring agents, milk fats, flavor enhancers, seasonings, sugars, heat coagulant or soluble proteins, amino acids and the like to neutralize residual alkali.

In this way, the product can be modified to have the taste and texture of fish meat. Of course, as mentioned above, these components can also be used in aqueous protein mixture solutions before freezing. Techniques requiring special treatment will be required when using these additives.

The following embodiments are provided to more specifically describe the present invention, and do not limit the present invention. Unless otherwise indicated, all parts and percentages are by weight.

Example 1

Soybean milk was used as a protein source to produce spun soy protein products with highly oriented and highly contoured fibers in fish tissue. Soybean milk was prepared by immersing 600 g of soybeans in water while changing water several times for 16 hours. The hydrated soybeans are then hot comminuted in boiling water, with water present at a ratio of 10: 1 relative to the soybeans. The resulting slurry was heated to boiling, held at this temperature for 15 minutes and filtered through a double cloth of cheese cloth. The residue on the cheese cloth was removed and the concentration of solids in the supernatant was measured. Then, the pH of the supernatant was adjusted to 7.5 using 2N sodium hydroxide, and antioxidant was added to the supernatant at a concentration corresponding to 0.02% of the fat content. Since the full fat soybean was used, the fat content of the supernatant was about 1/4 of the weight of solids present. Soybean milk was then placed in an aluminum plate to a depth of about 1 inch (2.54 cm).

The plate was placed on a piece of dry ice (-76 ° C) spread all over its bottom. Co-directional ice crystals were created that were substantially perpendicular to the bottom of the plate. This mass completely frozen within about 30 minutes. The frozen mass is then placed in liquid nitrogen for about 1 minute. During the period, the impact cooling causes the splitting plane to be in the alignment direction and the transverse direction of the fibers. The frozen mass was removed from the plate and immersed in 95% ethanol at a weight ratio of 1: 4 for 8 hours with stirring at a temperature between -5-10 ° C. The stabilized fibrous material was pressurized by applying a force perpendicular to the direction of the fibers in order to promote the release of ethyl alcohol contained in the spaces between these fibers. The pressurized product was then dried with air to remove moisture and residual ethanol components. The structure is strengthened by this drying process. This dried material was autoclaved at 15 psg for 10 minutes to reinforce the structure. Subsequently, the heat-treated material was immersed in water for about 20 minutes to be rehydrated to obtain a smooth, chewable fish meat fiber that was easily separated.

Example 2

Soybean milk was used as a protein source to produce spun soy protein products with high degree of orientation in fish tissue and having well-defined fibers. Soybean milk was prepared by immersing 600 g of soybeans in water overnight, changing the water several times. The soaked soybeans were then hot comminuted with boiling water, with water present at a ratio of 10: 1 relative to the soybeans. The resulting slurry was heated to boil, held at this temperature for 15 minutes, and filtered through a double cloth of cheese cloth. The residue on the cheese cloth was removed, the concentration of the supernatant was adjusted to 7.5 using 2N sodium hydroxide, and antioxidant was added to the supernatant at a concentration corresponding to 0.02% of the fat content. Since complete fatty soybeans were used, the fat content in the supernatant was about 1/4 of the solids present weight. The soybean milk was then decanted into a 2-inch cellulose sausage casing up to about one feed high. The casing was lowered at 1/2 inch (1.77 cm) intervals in a bath cooled to -40 ° C. Soymilk is frozen to a height of about 1.5 inches (4.31 cm) above the surface of the bath each time before further lowering the casing until the ice-liquid interface is about 1 inch (2.54 cm) above the bath surface. Ice crystals in the same direction occur substantially perpendicular to the surface of the bath. Lowering the casing from the air above the tub into the tub creates impact stress of the mass and breaks in a weak plane due to the temperature difference between the masses when kept above and below the surface of the tub. The frozen mass was removed from the plate and immersed in ethanol at a weight ratio of 1: 4 for 8 hours with stirring at a temperature between -5-10 C. The stabilized fibrous material was pressurized by applying a force perpendicular to the direction of the fiber in order to promote the release of ethyl alcohol contained in the space between these fibers. The pressurized product was then dried with air to remove moisture and residual ethanol components. The tissue is strengthened by this drying process. The dry material was autoclaved at 15 psig for 10 minutes to enhance tissue. The heat-treated material was then immersed in water for about 20 minutes and rehydrated to obtain a smooth, chewable fish meat fiber.

Example 3

The method of Example 2 was repeated, but this time the material was lyophilized instead of immersed in ethanol. The lyophilized material was then wet heat treated at 15 psig for 10 minutes to stabilize the tissue.

Example 4

Fibrous soy protein products were prepared from soy protein isolates. 100 g of soy protein isolate (91% protein) was mixed with 900 g of water to make a 10% solution and the pH value was adjusted to 7.0-8.0. This solution was placed in the plate to a depth of about 1 inch (2.54 cm) and frozen and stabilized as described in Example 1.

Example 5

Fibrous protein products were prepared from peanut protein isolates. 150 g of peanut protein isolate (93% protein) was mixed with 850 g of water to make a 15% solution and the pH value was adjusted to 7.0-8.0. This solution was placed in the plate to a depth of about 1 inch (2.54 cm) and frozen and stabilized as described in Example 3.

Example 6

Fibrous egg albumin products were prepared with fresh egg whites. Several egg whites were separated from egg yolk, placed in a plate, and frozen and stabilized as described in Example 1. Here, 10% egg albumin solution prepared from egg white powder can be used successfully.

Example 7

Fibrous fish protein products were prepared as a 15% mixed aqueous solution of fresh fish meat. To prepare the aqueous mixture solution, 150 g of lean meat was homogenized using 850 ml of 3% NaCl cold water solution in the wear mixture under vacuum for about 5 minutes. The resulting homogeneous mixture was then placed in a plate and frozen and stabilized as described in Example 2.

Example 8

The method of Example 1 was repeated again, but this time the soybean milk was concentrated as follows. The pH of the soybean milk was adjusted to 4.5 by the addition of HCl (1N). The resulting precipitate was centrifuged at 5000 × G for 20 minutes. The supernatant was decanted. The precipitate was transferred to a mixer and mixed with water for 20 minutes to give a soft and concentrated (18-20% solids) soybean milk. The soybean milk slurry was then adjusted to pH 7.5 with 2N sodium hydroxide and the resulting solution was placed in a plate and frozen as in Example 1.

Claims (1)

The mixture of thermocoagulant protein and water is cooled to freeze the water into ice crystals of long lengths, separating them into independent ice crystals with clear and ordered shapes, and the temperature at the fragile line in the frozen aggregates perpendicular to these ice crystals. The frozen mass is cooled or warmed at a temperature of at least 50 ° C. above the temperature of the frozen mass to generate stress, and the protein in the frozen mass is sufficiently stabilized by lyophilization or immersion in an aqueous solution of edible organic solvent. A method for producing a fibrous protein body, characterized in that the protein is solidified by heating the stabilized protein.