JP7722183B2 - Processed meat foods and their manufacturing methods - Google Patents

Description

The present invention relates to processed meat foods using porous protein materials and methods for producing the same.

Meat processed foods made from ground meat, such as hamburgers, meatballs, and meatballs, are sterilized by high temperatures, such as baking, and then the secondary cooking process, which occurs when the consumer eats them, causes the moisture and fats in the dough to drip out, resulting in a dry texture that lacks juiciness. Furthermore, shrinkage during cooking reduces the volume, resulting in poor appearance and yield, and a significant deterioration in quality in terms of texture and flavor.

To solve these problems, various studies have been conducted using protein ingredients. Patent Document 1 discloses a technique in which powdered soy protein is sprinkled on ground meat, a technique relating to a composition for ground meat or ground meat-like processed foods in which solid oil is dispersed in a paste based on vegetable protein material and water (Patent Document 2), and a technique relating to a ground meat processed food in which a protein solution is coated on the surface of the ground meat processed food and then heated (Patent Document 3).

Japanese Patent Application Publication No. 8-056615 JP 2011-139684 A JP 2008-104367 A Special Publication No. 54-23971

The techniques disclosed in Patent Documents 1 to 3 do not necessarily provide a fully satisfactory chewiness and juiciness of processed meat foods, and further improvements are desired.
The present invention aims to provide a processed meat food that is juicy and chewy.

After extensive research into solving the above problems, the inventors discovered that by using a porous protein material with specific properties as a raw material, it is possible to obtain processed meat foods that are juicy and chewy, and thus completed the present invention.

That is, the present invention provides:
(1) A porous protein material containing a powdered vegetable protein material and having the following characteristics A to E, and a meat processed food containing meat:
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption rate is 2 times or more by weight,
(2) The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption capacity is 9 times by weight or more, and E. Oil absorption capacity is 3 times by weight or more,
The processed meat food according to (1),
(3) The requirement B of the porous protein material is:
B. NSI is 40 or less;
The processed meat food according to (1),
(4) The requirement B of the porous protein material is:
B. NSI is 40 or less;
(2) The processed meat food according to (2),
(5) A method for producing a processed meat food, which comprises adding 0.1 to 5% by weight of a porous protein material containing meat and a powdered vegetable protein material and having the following characteristics A to E to the meat, kneading and molding the mixture, and heating the mixture.
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption rate is 2 times or more by weight,
(6) The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption capacity is 9 times by weight or more, and E. Oil absorption capacity is 3 times by weight or more,
(5) A method for producing a processed meat food according to (5),
(7) The requirement B of the porous protein material is:
B. NSI is 40 or less;
(5) A method for producing a processed meat food according to (5),
(8) The requirement B of the porous protein material is:
B. NSI is 40 or less;
(6) The method for producing a processed meat food according to (6),
(9) A method for imparting a juicy texture to processed meat foods, comprising adding 0.1 to 5% by weight of a porous protein material containing meat and a powdered vegetable protein material and having the following characteristics A to E to the meat, kneading and molding the mixture, and heating the mixture;
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption rate is 2 times or more by weight,
(10) The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption capacity is 9 times by weight or more, and E. Oil absorption capacity is 3 times by weight or more,
(9) The method for imparting a juicy feel to a processed meat food according to (9),
(11) The requirement B of the porous protein material is:
B. NSI is 40 or less;
(9) The method for imparting a juicy feel to a processed meat food according to (9),
(12) The requirement B of the porous protein material is:
B. NSI is 40 or less;
(10) The method for imparting a juicy feel to a processed meat food according to (10),
is.
In other words, the present invention provides:
(13) A porous protein material containing a powdered vegetable protein material and having the following characteristics A to E, and a meat processed food containing meat:
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption ratio is 2 times or more,
(14) The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption rate is 9 times or more by weight;
E. Oil absorption ratio is 3 times or more,
(13) The processed meat food according to (13),
(15) A method for producing a processed meat food, which comprises adding 0.1 to 5% by weight of a porous protein material containing meat and a powdered vegetable protein material and having the following characteristics A to E to the meat, kneading and molding the mixture, and heating the mixture.
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption ratio is 2 times or more,
(16) The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption ratio is 9 times or more by weight,
E. Oil absorption ratio is 3 times or more,
(15) The method for producing a processed meat food according to (15),
(17) A method for imparting a juicy texture to a processed meat food, comprising adding 0.1 to 5% by weight of a porous protein material containing meat and a powdered vegetable protein material and having the following characteristics A to E to the meat, kneading and molding the mixture, and heating the mixture;
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption ratio is 2 times or more,
is.

The present invention makes it possible to obtain processed meat foods that are juicy and chewy.

1 shows microscopic photographs at 100x and 300x magnification of test samples 3 and 4 obtained in Example Test 1, and the particles of the soy protein isolate that was their raw material. It can be seen that test sample 4 has undergone a significant change in structure from the raw material soy protein isolate particles, with the particles becoming coarse and irregularly shaped.

(Meat processed food)
The processed meat food of the present invention is characterized by containing a powdered vegetable protein material, a porous protein material having the following characteristics A to E, and meat.
A. Protein content is 50% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm ³ or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption ratio is 2 times or more.

By blending a porous protein material having the above-mentioned specific properties with processed meat foods, processed meat foods that are excellent in juiciness and chewiness can be obtained.
In the present invention, processed meat foods are considered delicious when they are juicy and release juices when eaten, and are not too soft and have a certain degree of chewiness, and therefore juiciness and chewiness are evaluated.
In the present invention, "juiciness" is evaluated based on the juice retention rate described below, and "chewiness" is evaluated based on the analytical value of the maximum test force (gf) obtained using a texture analyzer.
Next, the ratio (A) of the value of the meat juice retention rate to the control (without additives) and the ratio (B) of the value of the maximum test force to the control (without additives) are calculated.
The value calculated using the following formula based on these values is used to evaluate the processed meat food of the present invention.
(formula)
Evaluation of processed meat foods = (A) x (B)
If the value of "(A) x (B)" is 1.75 or more, the processed meat food is judged to be tasty and acceptable. The value of "(A) x (B)" is preferably 1.80 or more, more preferably 1.90 or more, even more preferably 2.00 or more, still more preferably 2.30 or more, and most preferably 2.50 or more.

The ratio (A) of the value of the meat juice retention rate to the control (without additives) is preferably 1.10 or more, more preferably 1.20 or more.
Incidentally, regarding the magnification (B) of the maximum test force relative to the control (without additives), if the magnification relative to the control is too high, it may affect the texture, so the magnification (B) of the maximum test force relative to the control (without additives) is generally 4.00 or less, preferably 3.50 or less, more preferably 3.00 or less, and even more preferably 2.50 or less. The lower limit is preferably 1.20 or more, more preferably 1.30 or more, even more preferably 1.40 or more, even more preferably 1.50 or more, even more preferably 1.70 or more, even more preferably 1.80 or more, even more preferably 1.90 or more, even more preferably 2.00 or more, and even more preferably 2.10 or more.

Examples of processed meat foods include hamburger steak, meatballs, meatballs, fish balls, minced meat cutlets, croquettes, chicken, gyoza, shumai, meat buns, etc. Hamburger steak, minced meat cutlets, or gyoza are preferred, and hamburger steak or gyoza are more preferred.
The meat used as a raw material is not particularly limited, but examples thereof include beef, pork, chicken, mutton, horse meat, venison, and fish meat. One or more of these meats can be used. In the present invention, meat also includes ground meat.
The amount of the porous protein material of the present invention added to meat is generally 0.1 to 5% by weight, preferably 0.3 to 4% by weight, more preferably 0.5 to 3% by weight, even more preferably 0.6 to 3% by weight, still more preferably 0.7 to 2% by weight, and most preferably 0.8 to 2% by weight.
By adjusting the amount of the porous protein material added to fall within this range, a processed meat food product that is juicy and chewy can be obtained.

The raw materials used in this invention include meat, porous protein materials, and other ingredients commonly used in the production of processed meat foods, such as vegetables such as onions and cabbage, seafood such as shrimp and shellfish, eggs, breadcrumbs, seasonings, and spices.

(Porous protein material)
The characteristics of the porous protein material used in the present invention will be specifically explained below.
The term "porous" refers to having many pores, such as charcoal or zeolite.

Protein: The porous protein material of the present invention is characterized by containing 50% or more by weight of protein per dry weight. The protein content can be, as a lower limit, 55% or more by weight, 60% or more by weight, 65% or more by weight, 70% or more by weight, 75% or more by weight, 80% or more by weight, 85% or more by weight, or 90% or more by weight per dry weight. The content can also be 99% or less by weight, 95% or less by weight, 90% or less by weight, 85% or less by weight, or 80% or less by weight per dry weight.
The protein content is calculated by multiplying the amount of nitrogen analyzed by the Kjeldahl method by a nitrogen conversion factor of 6.25.

○Water solubility (low water solubility)
The porous protein material of the present invention exhibits low water solubility. The water soluble nitrogen index (NSI) can be used as an indicator of water solubility, with the lower the NSI, the lower the water solubility. As an indicator of low water solubility, the porous protein material of the present invention has an NSI of 50 or less, preferably 45 or less, 40 or less, preferably 35 or less, and more preferably 30 or less.

NSI can be expressed as the ratio (by weight) of water-soluble nitrogen (crude protein) to the total nitrogen amount based on a predetermined method, and in the present invention, it is a value measured in accordance with the following method.
Specifically, 60 ml of water was added to 3 g of sample, and the mixture was stirred with a propeller at 37°C for 1 hour, then centrifuged at 1400 x g for 10 minutes, and the supernatant (I) was collected. Next, 100 ml of water was added to the remaining precipitate, and the mixture was stirred with a propeller at 37°C for another hour, then centrifuged, and the supernatant (II) was collected. Solutions (I) and (II) were combined, and water was added to the mixture to make 250 ml. This was filtered through a No. 5 filter paper, and the nitrogen content of the filtrate was measured by the Kjeldahl method. The nitrogen content of the sample was also measured by the Kjeldahl method, and the ratio of the amount of nitrogen recovered in the filtrate (water-soluble nitrogen) to the total nitrogen content in the sample, expressed as a weight percent, was used as the NSI.

Bulk Density The porous protein material of the present invention is characterized by its small bulk density, specifically, 0.2 g/ ^cm3 or less, preferably 0.15 g/ ^cm3 or less, more preferably 0.12 g/ ^cm3 or less, even more preferably 0.1 g/ ^cm3 or less, and most preferably less than 0.1 g/ ^cm3 .

Absorption Capacity The porous protein material of the present invention is characterized by its higher water absorption capacity compared to conventional textured soy proteins. Absorption capacity can be used as an index of water absorption level. The porous protein material of the present invention has a water absorption capacity of 7.5 times by weight or more, and can also be 8 times by weight or more, 8.5 times by weight or more, or 9 times by weight or more. In contrast, conventional commercially available textured soy proteins have a water absorption capacity of approximately 3.3 to 7.4 times by weight. The water absorption capacity is measured by the following method.

- Measurement conditions for water absorption capacity: 100 g of 80°C water is added to 10 g of sample. After absorbing water for 20 minutes, the water is drained in a 30-mesh colander and the weight (X g) of the sample after water absorption is measured. The water absorption capacity (Y) is then calculated using the following formula.
Y=(X-10)/10

Oil Absorption Ratio The porous protein material of the present invention is also characterized by its higher oil absorption ratio compared to conventional textured soybean proteins. Oil absorption ratio can be used as an index of oil absorption level. The porous protein material of the present invention has an oil absorption ratio of 2 times or more by weight, and can also be 3 times or more by weight, 4 times or more by weight, 5 times or more by weight, or 6 times or more by weight. In contrast, conventional commercially available textured soybean proteins have an oil absorption ratio of about 0.8 to 1.7 times by weight, which is not very high, but the porous protein material of the present invention can exhibit an oil absorption ratio of 3 times or more than that of conventional textured soybean proteins. The oil absorption ratio is measured by the following method.

Measurement conditions for oil absorption capacity: 100 g of palm oil at 80°C is added to 10 g of sample. After absorbing the oil for 20 minutes, the water is drained in a 30-mesh colander, and the weight of the sample after oil absorption (X g) is measured. The oil absorption capacity (Z) is then calculated using the following formula:
Z=(X-10)/10

○Form (granular, amorphous, average particle size, color tone)
The porous protein material of the present invention is typically in the form of granules. In the present invention, the term "granules" refers to particles having a particle size larger than that of powder.
The size of the granules is not particularly limited, but it is appropriate that 90% by weight or more of the total granule weight passes through a 42 mesh sieve according to the international standard "ISO 3301-1." However, the porous protein material of the present invention can also be appropriately pulverized before use, in which case it will be in the form of finer granules or powder.

The porous protein material of the present invention is characterized by the fact that it is typically an amorphous granule that does not have a specific, fixed shape, possibly because the powder aggregates and bonds together to form coarse particles due to the pressurized and heated powder treatment. On the other hand, examples of regular granules include textured protein materials produced using a twin-screw extruder and extrusion-granulated granules. Textured protein materials are obtained by kneading raw materials and water in an extruder to form a dough, which is then expanded by pressure and heat treatment, and extruded under normal pressure through a fixed die attached to the tip of the extruder, and then cut into a fixed shape at regular intervals at the extruder's outlet. Therefore, the porous protein material of the present invention is distinguishable in shape from textured protein materials produced using a twin-screw extruder.

The porous protein material of the present invention can also be characterized by a whiter, brighter color tone than conventional textured protein materials. That is, when the color tone of a pulverized porous protein material is measured using a color difference meter with reflected light, the lightness (L value) in the Hunter-Lab color system is 75 to 100, more preferably 80 to 95, and even more preferably 84 to 90. The brownness (a value) is -5 to 1.5, preferably -4 to 0, more preferably -3 to -0.3, and even more preferably -2 to -0.7. The yellowness (b value) is 0 to 18, preferably 5 to 17, more preferably 10 to 16, and even more preferably 12 to 15.6. The above-mentioned L value ranges and a value ranges may be selected and combined in any combination.
Incidentally, as an example of the color tone of "Fujinic PT-FL" (manufactured by Fuji Oil Co., Ltd.), a product of textured soy protein produced using a conventional twin-screw extruder, the L value is 70.3, the a value is 2.4, and the b value is 18.8. The color tone is low in brightness and has a strong brownish color, which is significantly different from the product of the present invention. On the other hand, as an example of the color tone of "Fujipro E" (manufactured by Fuji Oil Co., Ltd.), a product of powdered isolated soy protein, the L value is 83.4, the a value is -0.64, and the b value is 15.8. The porous protein material of the present invention can be as bright as or brighter than powdered isolated soy protein and have a low brownish color. When measuring the color tone, the pulverized sample is pulverized to an average particle diameter of 60 to 70 μm.

(Production of porous protein material)
The manufacturing method of the porous protein material of the present invention will be specifically described below.

In the present invention, the term "powdered vegetable protein material" refers to a protein material obtained by removing all or some of the components other than protein, i.e., lipids, soluble carbohydrates, starch, insoluble fiber (okara), minerals, etc., from a vegetable raw material, and then powdering the resulting product to have a more concentrated protein content. The protein content of the solid content is preferably 50% by weight or more, and can also be 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more.

Powdered vegetable protein materials can be obtained from a variety of plant-based sources, including legumes such as soybeans, peas, mung beans, chickpeas, peanuts, almonds, lupins, pigeon peas, jack beans, vine beans, kidney beans, adzuki beans, cowpeas, lentils, fava beans, and carob; seeds such as rapeseed (particularly canola varieties), sunflower seeds, cottonseed, and coconut; and whole grains and ground grains such as wheat, barley, rye, rice, and corn. Residues from industrially extracted oils and starches can also be used. The major proteins typically contained in these plant-based sources have an isoelectric point around pH 4.5. Commercially produced vegetable protein isolates from soybeans, peas, mung beans, and rapeseed (canola) seeds, as well as residues from the extraction of these oils or starches, are particularly preferred. Typical examples of powdered vegetable protein materials obtained from soybeans include isolated soybean protein, concentrated soybean protein, curd powder, defatted soy milk powder, low-fat soy milk powder, and hydrolysates thereof.

The powdered vegetable protein material may be a single type or a mixture of multiple types in a desired ratio and used as a raw material. For example, a powdered vegetable protein material may be used in conjunction with a powdered animal protein material, if necessary. More specifically, a powdered soy protein material and a powdered milk protein material may be mixed in a ratio of 1:10 to 10:1 and used as a raw material.
Food ingredients other than the powdered vegetable protein material can also be appropriately mixed in. These food ingredients are preferably in powder form, but may be mixed in liquid form as long as they do not affect the powder pressurization and heating process. Examples of such ingredients include starch, water-soluble dietary fiber, sugars, salts, seasonings, acidulants, sweeteners, bittering agents, oils and fats, emulsifiers, antioxidants, vitamins, trace nutrients, and colorings.

Here, a typical but non-limiting example of the production of isolated soybean protein is given below, using soybeans as an example. Plant isolated proteins can also be produced using other plant materials in accordance with the following production example.
I) Extraction Step Defatted soybeans are used as the soybean raw material, and water is added to the soybeans, followed by stirring or the like to form a suspension (slurry), from which protein is extracted with water. The water can have a neutral to alkaline pH and can also contain salts such as calcium chloride. The soybean refuse is separated from the water by solid-liquid separation means such as centrifugation to obtain a protein extract (so-called soy milk). At this stage, the product is heat-sterilized and spray-dried to produce so-called defatted soy milk powder, which can also be used as a powdered vegetable protein material.
II) Acid Precipitation Step Next, an acid such as hydrochloric acid or citric acid is added to the protein extract to adjust the pH of the extract to 4 to 5, which is the isoelectric point of soybean protein, to insolubilize the protein and cause acid precipitation. Next, a supernatant (so-called whey) containing acid-soluble components such as carbohydrates and ash is removed by solid-liquid separation means such as centrifugation, and an "acid-precipitated curd" containing acid-insoluble components is recovered. The product spray-dried at this stage is so-called curd powder, which can also be used as a powdered vegetable protein material.
III) Neutralization Step Next, water is added to the acid-precipitated curd again, and the curd is washed with water as necessary to obtain a "curd slurry." An alkali such as sodium hydroxide or potassium hydroxide is then added to the slurry to neutralize it, obtaining a "neutralized slurry."
IV) Sterilization and pulverization step Next, the neutralized slurry is heat sterilized, spray dried using a spray dryer or the like, and, if necessary, subjected to fluidized bed granulation to obtain isolated soy protein.
However, the isolated soy protein of the present invention is not limited to that produced in the above production examples. As the soybean raw material, various soybean raw materials such as full-fat soybeans or partially defatted soybeans can be used instead of defatted soybeans. Various extraction conditions and devices can also be applied to the extraction method. As a method for removing whey from a protein extract, membrane concentration using an ultrafiltration membrane or the like can be performed instead of acid precipitation, and in that case, the neutralization step is not necessarily required. Furthermore, the isolated soy protein can also be produced by first washing the soybean raw material with acidic water or alcohol to remove the whey, and then extracting the protein with neutral or alkaline water. Furthermore, the protein solution can be treated with a protease at any of the above stages to partially hydrolyze the protein.

The powdered vegetable protein material used as a raw material in the present invention may be highly water-soluble. An indicator of high water solubility is the NSI (Nitrogen Solubility Index) of at least 60 or higher, and may be 65 or higher, 70 or higher, 75 or higher, 80 or higher, 82 or higher, 85 or higher, 90 or higher, 92 or higher, 94 or higher, or 96 or higher. Powdered vegetable protein materials with these relatively high NSIs do not disperse well in water, and lumps, known as "mamako," float to the surface of the aqueous solution, making them difficult to dissolve quickly in water.

Granulation by pressure and heat treatment in powder state The powdered vegetable protein material of the present invention is characterized in that the above-mentioned powdered vegetable protein material is pressure and heat treated in powder state by direct heating with steam, not in an aqueous system. By this process, the powdered vegetable protein material is granulated, and the porous protein material of the present invention can be produced.

The pressure during the pressurized heating treatment can be set as appropriate so that the porous protein material has the desired quality, but is preferably 0.3 MPa or more or 0.4 MPa or more, and the heating pressure can be 0.9 MPa or less, 0.8 MPa or less, 0.7 MPa or less, 0.6 MPa or less, 0.5 MPa or less, or 0.4 MPa or less. In one preferred embodiment, a range of 0.3 to 0.7 MPa can be selected.

The temperature during pressure heating treatment varies depending on the pressure, and because it is under pressure, it can exceed 100°C, and in some cases can reach 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, or 170°C or higher. There is no set upper limit to the temperature, but it is usually below 250°C.

The heating time for the pressurized heat treatment can be set appropriately in combination with the heating temperature so that the porous protein material has the desired quality, but a shorter time is preferable, and can be 1 minute or less, 30 seconds or less, 20 seconds or less, 10 seconds or less, 5 seconds or less, 2 seconds or less, 1 second or less, and particularly 0.5 seconds or less or 0.3 seconds or less. The heating time can also be 0.00001 seconds or more, 0001 seconds or more, or 0.001 seconds or more. In one preferred embodiment, the range can be selected from 0.00001 to 2 seconds, 0.0001 to 1 second, or 0.001 to 0.5 seconds.

Heating methods for pressure and heat treatment can be broadly classified into direct heating and indirect heating, but the present invention is characterized by employing a direct heating method using steam. Powder heat treatment equipment capable of performing such pressure and heat treatment includes airflow-type powder sterilizers such as the "KPU" (Okawahara Manufacturing Co., Ltd.), "SKS-50" (Seishin Enterprise Co., Ltd.), and "Sonic Stera" (Fujiwara Techno Art Co., Ltd.), as well as improved versions of these. In this way, by using a direct heating method using steam such as superheated steam to directly expose powdered vegetable protein material powder to steam and perform pressure and heat treatment, the powdered vegetable protein material can be aggregated and granulated.

Furthermore, in the present invention, it is important that, in the pressure heating treatment using the direct heating method, the powdered vegetable protein material is subjected to pressure heating treatment using direct heating with steam while being dropped vertically in a powder state. A heating and pressurizing device for carrying out such a heating method is preferably provided with a closed heating space in which powder introduced into the device can drop vertically, and has a mechanism for contacting the powder with steam under pressure as it falls through the space. In the present invention, such a pressure heating device is referred to as a "vertical type." As an embodiment of the vertical type, a powder or granular sterilizer such as that disclosed in International Publication WO 2009/145198 can be used as the pressure heating device, and specifically, the commercially available "Sonic Stera" (manufactured by Fujiwara Techno-Art Co., Ltd.) can be used.
This makes it possible to produce a porous protein material that has excellent water absorption properties and also excellent oil absorption properties.

On the other hand, when powder heating is performed using a "horizontal-type" pressure heating device, which has a closed, horizontally positioned heating space where pressure is applied using steam, and uses highly water-soluble vegetable protein as the raw material, the powder sticks to the inside of the device, resulting in inefficient production. Furthermore, while the mechanism is unclear, according to prior art patent document 4, the resulting granules have a water absorption capacity of around 2 to 3 times, which is insufficient.

In addition, the twin-screw extruder used in the production of conventional textured protein materials is also used as a powder sterilization device, but it is an indirect heating method of pressurized heat treatment, and is not a heating method in which water vapor is directly exposed to the powder, so it is a completely different method from the pressurized heat treatment of the present invention.

The porous protein material produced in the above manner can be used as a finished product as is. If necessary, it can be further processed, for example, by pulverizing or crushing to an appropriate particle size. It can also be passed through a classifier to fractionate into granules of the desired particle size range, thereby obtaining a sized porous protein material.

(Method of manufacturing processed meat foods)
Dough Preparation Method The manner of mixing or kneading the ingredients and the manner of subsequent cooking and heating will vary depending on the type of processed meat food of the present invention. For example, the following will be taken as an example of processed meat foods using minced meat, such as hamburger steaks and meatballs. The processed meat food of the present invention can be produced by mixing, kneading, shaping, and cooking and heating the above-mentioned meat, porous protein material, and other ingredients.
The meat can be used in minced form. The minced meat is usually several millimeters in diameter and is further shredded or made into a paste in the subsequent mixing or kneading process. The mixing or kneading method in the present invention can be performed using known equipment such as a mixer or silent cutter, or by hand kneading. A silent cutter can also be used to create a paste that eliminates the graininess of the meat. These mixing or kneading methods can be applied not only to processed meat foods but also to processed foods using seafood, such as fish balls.

Method of forming the dough The mixed or kneaded ingredients of a processed meat food can be shaped according to the type of processed meat food. For example, a processed meat food using minced meat such as a hamburger steak can be taken as an example. The mixed ingredients as described above can be filled into a mold and shaped by cutting.

Cooking and Heating The molded processed meat food of the present invention can be cooked and heated, for example, by baking, frying, steaming, or the like.

The present invention will be explained by the following examples. In the examples, parts and percentages are by weight unless otherwise specified.

(Test 1)
As described below, the powdered vegetable protein material was subjected to pressure heating treatment using a direct heating method with steam while in a powder state.
The commercially available soy protein isolate "Fujipro F" (manufactured by Fuji Oil Co., Ltd.) was used as a sample of powdered vegetable protein material. This sample had a protein content of 91.2% and was a highly water-soluble type with an NSI of 98.6.
The pressure heating device used was the commercially available "Sonic Stera" manufactured by Fujiwara Techno Art Co., Ltd. This is a vertical type device that can perform pressure heating treatment using a direct heating method with steam while dropping powder vertically within the heating space.
Soy protein isolate was subjected to powder pressure heating treatment under the heating conditions in Table 1, and the moisture content, NSI, and bulk density of the resulting treated products were measured and summarized in Table 1 (test products 1 to 4). For quality comparison, various data on the above soy protein isolate and commercially available textured soy protein products A to D (manufactured by Fuji Oil Co., Ltd. using a twin-screw extruder) are also listed.

(Table 1)

Under the heat treatment conditions for test samples 1 to 3, the product was in a powdery or fine granular state, had an NSI of 60 or more, and had a bulk density similar to that of isolated soy protein or textured soy protein. However, under the heat treatment conditions for test sample 4, which is a product of the present invention, the shape changed to an "irregular" granular state, the NSI fell to 40 or less, and the bulk density became as small as 0.2 g/ ^cm3 or less, resulting in properties significantly different from test samples 1 to 3.
In contrast, textured soy protein was formed by cutting at regular intervals at the outlet of the twin-screw extruder, resulting in granules with a "nearly fixed" shape, and tended to have a higher bulk density than Test Sample 4.

(Test 2) Microscopic Observation Test samples 3 and 4 and the raw material soy protein isolate were observed using a tabletop microscope, "Miniscope TM-1000" (Hitachi High-Technologies Corporation). Figure 1 shows photographs of particles observed at 100x and 300x magnification for each sample. As is clear from the photographs, the particle shapes of the soy protein isolate and test sample 3 were almost identical, but the particles of test sample 4 had aggregated and become coarse and irregular.

(Test 3) Comparison of Water and Oil Absorbency The water and oil absorbency of test products 3 and 4 obtained in Test 1, isolated soy protein, textured soy protein A to D, and breadcrumbs was investigated. The results are shown in Table 2.

(Table 2)

Test sample 4 had higher water and oil absorption rates than test sample 3. In particular, the oil absorption rate was more than two times higher. Furthermore, test sample 4 had completely different water and oil absorption rates from isolated soy protein, and both the water and oil absorption rates were higher than those of commercially available textured soy proteins A to D. Textured soy protein D had relatively high water and oil absorption rates, but test sample 4 had even higher water and oil absorption rates, with the oil absorption rate being more than three times higher. Furthermore, the water and oil absorption rates of test sample 4 were significantly higher than those of breadcrumbs.

(Test 4) Comparison of Color Tone The color tones (Hunter-Lab color system) of Test Product 4, isolated soy protein, and textured soy protein D obtained in Test 1 were measured using a colorimeter to examine the lightness (L value), brownness (a value), and yellowness (b value). Test Product 4 and textured soy protein D were previously finely pulverized to an average particle size of 60-70 μm using a grinder "Micro Powder KGW G-015" (manufactured by Makino Sangyo Co., Ltd.) before being subjected to analysis. The results are shown in Table 3.

(Table 3)

Test product 4 had a much higher brightness, a much lower brownness, and a lower yellowness compared to textured soy protein D. It also had a similar color tone compared to the raw material, isolated soy protein, but tended to have a higher brightness and lower brownness and yellowness, and tended to have a whiter, brighter appearance.

(Test 5) Classification test Test sample 4 was classified using a test sieve (compliant with ISO 3310-1 standard) and the particle size distribution was measured. In addition, the water absorption capacity and oil absorption capacity of each classified sample were measured. The results are shown in Table 4.

(Table 4)

The proportion of granules that fit on 42 mesh (openings 0.355 mm) of the total granule weight of test product 4 was 92.4%, exceeding 90%. The finer the particles, the higher the water absorption capacity, with the product that passed through 20 mesh being the highest. Meanwhile, the oil absorption capacity was particularly high for the product that passed through 10 mesh/fitted on 20 mesh.

(Example 1, Comparative Examples 1 to 7) Evaluation of Hamburger Hamburger was used as a processed meat food product for evaluation.
Hamburger steaks were prepared by adding 1% of each of the ingredients shown in Table 5 to 30 g of commercially available domestically produced ground beef and pork (solid content: 4.6%) and kneading the mixture thoroughly by hand. Each hamburger steak was cooked in the following order (1) to (6) using an induction cooker (KZ-PH3, Panasonic) at the fifth heat level (medium heat).
(1) Place the oiled frying pan on the induction cooker, set the heat to level 5 (medium heat), and once it was hot, thoroughly wipe off the oil.
(2) Place the hamburger steak on a frying pan, cover it, and cook one side for 1.5 minutes.
(3) After 1.5 minutes, open the lid and flip the hamburger over.
(4) After 4 minutes of baking, the lid was opened and the pancake was turned over again. After that, the pancake was baked with the lid open.
(5) I turned off the heat 5 minutes after I started cooking.
(6) The hamburger steak was immediately removed from the frying pan and its weight was measured.

(Table 5)

(Hamburg steak evaluation)
Hamburg steaks were evaluated by assessing the juice retention rate and maximum test force.
Evaluation of Meat Juice Retention Rate In the present invention, the meat juice retention rate is evaluated based on the meat juice retention rate of the grilled processed meat food. That is, the meat juice retention rates of the processed meat foods containing various ingredients and the processed meat food without any ingredients (control) were calculated, and the ratio of the meat juice retention rate of the processed meat food containing various ingredients to the meat juice retention rate of the processed meat food without any ingredients was calculated.
The juice retention rate was calculated using the following formula:

Juice retention rate (%) = [30 x (100 - solids content of ground beef and pork) % x 0.01 - {(30 + added ingredients) - total weight of grilled processed meat food}] x 100 ÷ {30 x (100 - solids content of ground beef and pork) x 0.01}

Evaluation of maximum test force In the present invention, the maximum test force was evaluated by placing a sample (dough) on a pressure plate with a diameter of 118 mm using a texture analyzer (EZ-TEST, manufactured by Shimadzu Corporation), and applying pressure to the dough at a speed of 5 mm/sec using a round rod with a diameter of 18 mm and a height of 40 mm.
The ratio of the maximum test force of the processed meat food with the additive to the maximum test force of the processed meat food without the additive was calculated.

The value calculated using the following formula was used to evaluate the processed meat food of the present invention, with (A) being the multiplication factor of the above-mentioned meat juice retention rate value relative to the control (no additives) and (B) being the multiplication factor of the maximum test force value relative to the control (no additives).
Evaluation of processed meat foods = (A) x (B)

The evaluation results are shown in Table 6.

(Table 6)

The evaluation (value of (A) x (B)) of the processed meat food to which the porous protein material of the present invention was added was 2.72, a better result than that of conventional soy protein. Furthermore, even when materials other than soy protein were used, the numerical value was lower than that of the processed meat food to which the porous protein material of the present invention was added, resulting in a poor evaluation.

(Examples 2 and 3)
Tests were conducted using Test Product 1 in varying amounts. Hamburgers were prepared and evaluated in the same manner as in Example 1, except that Test Product 4 was added to the ground meat in amounts of 0.5% and 3.0%. The evaluation results for the tests in which Test Product 4 was added in amounts of 0.5% and 3.0% are shown in Tables 7 and 8, respectively.

(Table 7)

(Table 8)

As shown in Tables 7 and 8, good results were obtained when the porous protein material of the present invention was added to minced meat at 0.5% or 3.0%.

Claims (6)

A method for producing a processed meat food, comprising adding 0.1 to 5% by weight of a porous protein material to meat, which contains meat and a powdered vegetable protein material and has the following characteristics A to E, and which is obtained by granulating the material by subjecting the material to a pressure heating treatment using a direct heating method with steam at a pressure of 0.3 to 0.9 MPa for 0.00001 to 0.5 seconds while dropping the material vertically in a powdered state, and then kneading and molding the material, followed by heating.
A. Protein content is 60% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm3 or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption rate is more than 2 times the weight The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption capacity is 9 times by weight or more, and E. Oil absorption capacity is 3 times by weight or more,
The method for producing a processed meat food according to claim 1, wherein The requirements for porous protein material B are:
B. NSI is 40 or less;
3. The method for producing a processed meat food according to claim 1 or 2, wherein A method for imparting a juicy texture to processed meat foods, comprising adding 0.1 to 5% by weight of a porous protein material to the meat, which is obtained by granulating the porous protein material, which contains meat and a powdered vegetable protein material and has the following characteristics A to E, by subjecting the material to a pressure heating treatment using a direct heating method with steam at a pressure of 0.3 to 0.9 MPa for 0.00001 to 0.5 seconds while dropping the material vertically in a powdered state, followed by kneading, molding, and heating.
A. Protein content is 60% or more by dry weight;
B. NSI is 50 or less;
C. Bulk density of 0.2 g/cm3 or less;
D. Water absorption capacity is 7.5 times or more by weight;
E. Oil absorption rate is more than 2 times the weight The requirements A, D, and E of the porous protein material are:
A. Protein content is 75% or more by dry weight;
D. Water absorption capacity is 9 times by weight or more, and E. Oil absorption capacity is 3 times by weight or more,
5. The method for imparting a juicy texture to processed meat foods according to claim 4, wherein The requirements for porous protein material B are:
B. NSI is 40 or less;
6. The method for imparting a juicy texture to processed meat foods according to claim 4 or 5, wherein