JPH0452746B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a textured protein food,
In particular, the present invention relates to a method for producing a structured protein food suitable for dietary therapy for kidney disease, using soybeans with reduced phosphorus and potassium content and processed products thereof as raw materials. (Prior Art and its Problems) The technique of producing a textured protein food using a twin-screw extruder is well known. That is, water is added to the tissue material containing powdered or granular vegetable protein as a raw material so that the moisture content becomes 20% to 80%, at a temperature of 130°C to 170°C, and 10 to 100 kg/cm ²
It is homogenized, kneaded, and melted using a twin-screw extruder under pressure conditions of Low-strength proteins are used. The soluble nitrogen index (hereinafter referred to as NSI), which indicates the proportion of soluble protein in the protein, is used as an index of the degree of denaturation.
For example, whole soybeans, defatted soybeans, soybean isolate protein, etc. are used. On the other hand, recently, vegetable protein materials that have been largely denatured through various treatments have become available. In particular, if treatments such as high-temperature sterilization or hot air drying are performed to improve shelf life, the NSI will drop to at least 15 or less. When producing a textured protein food using these highly denatured protein materials as raw materials, sufficient texture cannot be achieved under conventional conditions. In addition, in recent years, in dietary therapy for kidney disease, it has traditionally been emphasized to control the intake of protein, minerals, etc. according to the disease state, but in recent years, many patients with kidney failure have osteodystrophy and hyperlipidemia. It has become clear that complications such as bloodemia occur, and it is hoped that a diet for kidney disease will be developed that can prevent or improve these complications. By the way, soybeans are rich in high-quality vegetable protein and are also known to have antihyperlipidemic effects. Therefore, structured protein foods made from soybeans are considered to be suitable as food for patients with kidney disease and the like. However, on the other hand, soybeans contain a large amount of potassium and phosphorus (approximately 2000 mg of potassium and approximately 600 mg of phosphorus per 100 g of edible portion), so in that sense they are not necessarily suitable for kidney disease patients. In other words, in patients with kidney disease, potassium and phosphorus are not excreted sufficiently, so for example, if potassium intake is high, blood potassium levels will rise, causing symptoms such as chest tightness and numbness in the hands and feet, and in the worst case, cardiac arrest. It may even lead to. In addition, high phosphorus intake increases blood phosphorus concentration, which may cause abnormalities in calcium metabolism such as osteodystrophy. However, conventional textured proteins are prepared using ordinary soybeans and processed products thereof as raw materials, and the amounts of phosphorus and potassium have not been sufficiently reduced. Therefore, by using soybeans with selectively reduced phosphorus and potassium contents in soybeans and processed products thereof as raw materials, a textured protein food can be made into a more desirable diet for kidney disease. In view of this situation, the present inventors have diligently investigated the conditions under which highly denatured protein materials or soybeans with selectively reduced phosphorus and potassium contents can be used as raw materials for structured protein foods. The invention has been completed. (Means for Solving the Problems) The present invention provides a structured protein that is processed using a twin-screw extruder and is made from a highly denatured vegetable protein with a reduced phosphorus and potassium content per protein and an NSI of 15 or less. An object of the present invention is to provide a method for manufacturing the same, and this object is achieved by the present invention. That is, the gist of the present invention is to use a processed soybean product with a lipid content of 5% or less as a raw material in producing a structured protein food suitable for diet therapy for kidney disease by performing twin-screw extruder processing, The raw material is immersed in an aqueous solution with a pH of 3.0 to 6.5, and then heat-treated to reduce the phosphorus content per gram of protein to 11.
mg or less, the calcium content is 40 mg or less, and the soluble nitrogen index (NSI) is 15 or less, and the material is subjected to twin-screw extruder treatment and kept at a temperature of 180°C or more and 250°C or less at least once during the treatment. This is a method for producing a structured protein food suitable for dietary therapy for kidney disease. The present invention will be explained in more detail below. (Detailed Description of the Invention) As the biaxial extruder used in the present invention, a conventionally used extruder can be used as is. For example, fully engaged screws for conveyance, kneading, and pressurization (for example, reverse screws with notches), two shafts rotating in the same direction that hold them,
A combination of a barrel with a heating device surrounding it, a die placed at the tip of the barrel through which processed raw materials are extruded, and a device for supplying raw materials and water into the barrel is used. What is important is the temperature at which the raw material is processed, that is, the temperature inside the barrel. In the case of raw materials with an NSI greater than 15, sufficient organization will occur if the temperature is maintained within the range of 130°C to 170°C, but in the case of raw materials with an NSI of 15 or less, organization will occur under such temperature conditions. is insufficient. Such raw materials must be kept at a temperature in the range of 180°C to 250°C at least once before being extruded through the die. In other words, if the temperature is lower than that, the amount of heat required to sufficiently knead and melt most of the insoluble proteins will not be supplied.
Also, if the temperature is too high, it will become so-called burnt,
Flavor is significantly impaired. For proper organization, the lipid content in the raw material is preferably 5% or less. This is because if the amount of lipid is larger than this, sufficient pressure cannot be obtained when extruding from the die. In such cases, measures are generally taken to increase the moisture content to emulsify well and increase pressure, while cooling the die to prevent the processed material from flying away from the die due to the increased moisture content. take lessons. However, in the case of highly modified raw materials of the present invention, it is difficult to produce sufficient emulsification even when such a method is used, so that a suitable texture cannot be obtained. The structured protein food produced in the present invention is often used as a raw material for cooking compositions or processed foods that normally use animal meat in place of part or all of the animal meat. Therefore, it is desirable that the main raw material for the textured protein is comparable to animal meat both in terms of nutritional value and from an economic point of view. Therefore, in the present invention, processed soybean products (eg defatted soybeans, okara, etc.) with a lipid content of 5% or less are used. In addition, many processed soybean products, such as okara, are easily spoiled, and it is preferable to sterilize or dry them by heat. Of course, most of the proteins in the raw materials are denatured through such a step, but one of the effects of the present invention is that even such materials can be sufficiently organized. Furthermore, when microorganisms are allowed to act on processed soybean products as raw materials to improve nutritional effects, flavor, physical properties, etc., it is important to ultimately kill off the microorganisms that act on them. In such cases, the protein is also denatured as described above, but it can be assembled under the conditions of the present invention. On the other hand, in the method of the present invention, treated soybeans whose phosphorus and potassium contents are selectively reduced compared to natural products are used as raw materials. The content of phosphorus and potassium in natural soybeans varies depending on their quality, production area, etc., but in general, the phosphorus content in 100g of edible portion is approximately 600%.
mg (approximately 17 mg per 1 g of protein), potassium approximately 2000 mg
mg (approximately 57 mg per gram of protein).
When soybeans are defatted, they contain about 600 mg of phosphorus and about 2,500 mg of potassium. The material used in the present invention contains about 420 mg or less of phosphorus (about 11 mg or less per 1 g of protein) and about 1400 mg or less (about 40 mg or less) of potassium per 100 g of edible portion, and preferably contains about 40 mg or less of potassium. 180mg or less (about 5mg or less), potassium about 600mg or less (about 5mg or less)
20mg or less). Although the phosphorus and potassium contents of such materials are reduced as described above, other useful components such as protein, lipids, calcium, iron, and vitamins are retained. This material is made from processed soybean products with a pH of 3.0.
The processed soybean product is produced by immersing it in an aqueous solution of ~6.5 to elute the phosphorus and potassium components in the processed soybean product into the aqueous solution, followed by heat treatment and, if necessary, drying. Processed soybean products used as raw materials are first subjected to a soaking treatment. An aqueous solution adjusted to pH 3.0 to 6.5 is used as the immersion liquid. As the pH adjuster for the aqueous solution, inorganic acids or organic acids commonly used in food processing are used. For example, acid salts, inorganic acids such as sulfuric acid and nitric acid, and organic acids such as formic acid, acetic acid, citric acid, lactic acid, adipic acid, malic acid, ascorbic acid and succinic acid are preferably used. The most important thing in such processing is the selection of soaking conditions that can reduce the phosphorus and potassium content without loss of useful components such as protein and lipid contained in the raw processed soybean product. Like soybeans, about 75% of the phosphorus in processed soybean products exists as phytic acid, but an enzyme called phytase is also present in processed products. It is known that phytic acid is hydrolyzed to produce inositol and phosphoric acid. Phytic acid itself has the property of being easily adsorbed by proteins, so it is difficult to separate from other soybean components, but phosphoric acid produced by phytic acid decomposition is relatively easily eluted into the soaking liquid, just like potassium. Therefore, the solution conditions involved in the expression of phytase activity, especially the pH and temperature of the immersion solution, are considered to be requirements that affect the efficiency of phosphorus removal. The raw soybean products are added to a dilute acidic solution,
Maintain the pH in the range of 3.0 to 6.5, preferably 3.5 to 6.0, and keep the liquid temperature at 10 to 80℃, preferably 20 to 70℃.
By stirring at a temperature of 0.degree. C., the phosphorus and potassium contents in the processed soybean product are reduced depending on the soaking time. Phosphorus and potassium contents can be reduced more quickly by increasing the ratio of the amount of soaking liquid to the solid content of processed soybean products, or by replacing the soaking liquid intermittently or continuously. . The soaking time is approximately 5 to 36 hours depending on the soaking temperature. PH during soaking
Since the PH value changes gradually, it is desirable to maintain it at a predetermined PH value using a PH controller, etc. Further, the processing of the processed soybean products includes, following the soaking treatment, separating the processed soybean products from the soaking liquid, and washing the separated processed soybean products with water having a pH of 5.0 to 9.0, preferably 6.0 to 8.0. Therefore, it can be carried out more suitably. Particularly when defatted soybeans are used as a raw material, adding the above-mentioned washing step further improves the phosphorus removal rate. The activity of phytase in soybeans is higher in acidic conditions, but undecomposed phytic acid remains in defatted soybeans after soaking, and the solubility of this phytic acid is higher near neutrality. The reason why the phosphorus removal rate increases when defatted soybeans are washed with near-neutral water is thought to be because phytic acid is thereby eluted. In the case of natural whole grain soybeans, phytic acid is adsorbed to the protein and is not easily eluted, but in the case of defatted soybeans, it is easily dissociated from the protein by the action of phytase, and it is released through the defatting process. It is presumed that the cell structure changes and the elution of phytic acid from inside the cells also becomes easier. After soaking, the processed soybean products are heat-treated to kill microorganisms that have grown during soaking, and if necessary, to facilitate handling of the processed soybean products. Then, it is dried. The heat treatment is usually carried out by steaming. As a result of such processing, the final result is a considerably reduced NSI. Possible causes of the decrease in NSI include low NSI of the raw material, denaturation during dipping treatment, denaturation during heat treatment, or denaturation during the drying process. Although the degree of involvement of each cause varies depending on the raw materials and the preparation procedure for processed soybeans, the final NSI is generally
It is 0.1 or more and 15 or less. After going through this process,
It is preferable to denature soybeans until the NSI becomes 15 or less from the viewpoint of deactivating various nutritionally inhibiting factors (such as trypsin inhibitors) in soybeans. Furthermore, when the textured protein according to the present invention is produced using processed soybean products subjected to the treatment as raw materials, more favorable effects can be expected than in the case of ordinary soybeans. In other words, since the small amount of soluble sugars contained in ordinary soybeans or this processed product have been virtually removed,
When processed at such high temperatures, it is possible to prevent phenomena such as browning that occur due to the reaction between sugars and proteins. The structured protein prepared in this way can be used in the production of meat-based cooked or processed foods (e.g. hamburgers, meatballs, gyoza, shiiyu mai, korotsuke, ham, sausages, etc.) as described above. It can be used in place of one part or all. In particular, cooked foods or processed foods prepared using textured proteins with reduced phosphorus and potassium can be suitably used in dietary therapy for kidney disease patients, as described above. Next, the present invention will be explained in more detail with reference to Reference Examples and Examples. Reference Example 1 10 g of defatted soybeans were soaked in 200 ml of water, acetic acid was added as appropriate, and the soaking liquid was stirred while maintaining the pH at 5.5 and the temperature at 50°C. Six hours after the start of immersion, the immersion liquid was discarded, 100 ml of water was added, and the mixture was stirred at room temperature for 30 minutes for washing. After discarding the washing solution and performing the same washing process once more, the soybeans were collected and heated (120°C, 10
) and then the soybeans were dried under reduced pressure. Similar operations were carried out by changing the soaking time and the number of washings, and the removal rates of phosphorus, potassium, and protein contained in processed soybeans were measured. The results are shown in Table 1.

[Table] Reference Example 2 1 kg of defatted soybeans was added to 20 g of water. Add acetic acid as appropriate to adjust the immersion liquid to a pH range of 5.0 to 6.0 and a temperature of 50℃.
The mixture was stirred while being maintained at . Three hours after the start of immersion, the immersion liquid was discarded, 10 ml of water was added, and the sample was stirred at room temperature for 30 minutes for washing. The washing liquid was discarded and the soybeans were washed two more times (three times in total), and then the soybeans were collected and dried under reduced pressure. The removal rate of phosphorus and potassium in the obtained processed soybeans was 90.7 each.
% and 96.0%. Edible (dry) 100
The content per g is 156 mg of phosphorus and 134 mg of potassium, and the content per g of protein is 2.88 mg of phosphorus,
Potassium was 2.48 mg. Example 1 50 kg of treated soybeans obtained in Reference Example 1 had a total moisture content of 25 kg.
It was processed using a twin-screw extruder while adding water so that the amount was %. The temperature of the kneading and extrusion portions was maintained at 190° C., and the mixture was extruded through a die to obtain a structured composition. In the resulting composition, 2.9 mg of phosphorus per gram of protein;
Potassium was 2.5 mg. Example 2 To 11 kg of the structured protein obtained in Example 1, 20 kg of onions, 6 kg of carrots, 5 kg of gluten, 8 kg of starch, 5 kg of lard, and some seasonings were added and kneaded well. The obtained composition was formed into balls of 30 g each and baked on an iron plate at 160°C to obtain a meatball-like food with extremely good flavor. The resultant contains 10% protein,
The amount of phosphorus and potassium per gram of protein was 3.5 mg and 7.9 mg, respectively. Example 3 To 20 kg of the textured protein obtained in Example 1, 10 kg of onion, 5 kg of gluten, 8 kg of starch, and a small amount of seasoning were added and kneaded well. The resulting composition was made into balls of 20 g each, wrapped in commercially available gyoza skin, then boiled in boiling water for 5 minutes, and then baked on an iron plate at 150°C for 5 minutes to improve the flavor. I got some good Giyoza-sama food. The resulting food contained 18% protein, with 3.5 mg of phosphorus and 4.3 mg of potassium per gram of protein. (Specific functions and effects of the present invention) The present invention is a method for producing a textured protein food by subjecting a vegetable protein material having a soluble nitrogen index (NSI) of 15 or less to twin-screw extruder treatment,
The temperature during processing is maintained between 180° and 250° at least once, the raw materials are made of soybeans and their processed products, the lipids contained in the raw materials are 5% or less, and the phosphorus and The method comprises a method for producing a textured protein food such as processed soybeans having a potassium content of 11 mg or less and 40 mg or less, respectively. According to the present invention, highly denatured cells that are difficult to organize properly using conventional methods can be used.
Textured protein foods can be prepared using proteins with an NSI of 15 or less as raw materials, and in addition, textured protein foods with lower phosphorus and potassium contents can be selectively produced compared to textured protein foods conventionally made using soybeans. can do. Furthermore, the phosphorus/potassium reduced protein can be used to prepare foods with reduced phosphorus and potassium, such as hamburgers, meatballs, gyoza, shiiyu mai, korotsuke, ham, and sausages. Phosphorus in foods combines with calcium during digestion and absorption to form insoluble calcium phosphate, which prevents calcium absorption. Therefore, the food according to the present invention with reduced phosphorus content is useful for dietary therapy for patients with kidney disease, as well as parathyroid disorders, vitamin D metabolism disorders, osteoporosis, and calcium or phosphorus metabolism disorders. Furthermore, the food according to the present invention having a low potassium content is useful for dietary therapy for patients with kidney disease as well as those with heart disease.

Claims (1)

[Claims] 1. When producing a structured protein food suitable for diet therapy for kidney disease using a twin-screw extruder process, processed soybean products with a lipid content of 5% or less are used as raw materials, and the raw materials are heated to pH 3.0~ 6.5, and then heat-treated to obtain 1g of protein.
Phosphorus content per unit is less than 11mg, potassium content is
The material must be 40mg or less and have a soluble nitrogen index (NSI) of 15 or less.The material must be subjected to twin-screw extruder treatment, and heated at 180℃ at least once during the treatment.
A method for producing a structured protein food suitable for diet therapy for kidney disease, characterized by being kept at a temperature of 250°C or less.