Application technology of soybean protein in meat products

Abstract: Plant-based proteins include wheat protein (gluten) and soy protein (water-soluble soy protein). Soy protein is widely used in meat processing. It not only increases the protein content in the product, but also plays an important role in the structure, flavor and quality characteristics of meat products.

Keywords: meat products, soy protein isolate

Related products for this article: Soy protein isolate

The types of soy protein commonly used in meat processing include powdered soy protein, fiber soy protein and granular soy protein. There are four types of powdered soy protein: defatted soy flour, dried soy milk, concentrated soy protein, and separated soy protein; fibrous soy protein includes two types: spinning type processed by chemical method and structural type processed by physical method. Due to various reasons, the spinning type has not been produced so far. The structural type has always been fibrous materials with a diameter of 1～2mm to 3～5mm; the granular soy protein is made of defatted soybeans. According to the needs, the separated soybean protein, pigment, flavor enhancer and water are added. Mix the mixture uniformly and make it melted, and then extrude from the small holes to obtain directional expanded pellets. This kind of product has a variety of different tissue hardness, moisture regain speed, density (concentration), water absorption, color tone, flavor, size, shape, etc.

The research team of China Foodstuff & Protein Group Co., Ltd. believes that the three soy proteins have different characteristics in meat products. The powdered separated soy protein has good water retention capacity. When the concentration is 12%, the viscosity rises sharply when the heating temperature exceeds 60°C. When it is heated to 80-90°C, let it stand and cool to form a smooth yarn-like gel. This feature will greatly help improve the quality of meat when the separated soy protein enters the meat tissue. Soy protein has the two characteristics of a hydrophilic group that is easy to combine with water and a hydrophobic group that is easy to saturate with oil. Therefore, it has good emulsifying power; the characteristics of granular and fibrous soy protein are different from those of powdered soy protein, and both have a strong heat-denatured tissue structure. It has water retention, oil retention and meaty texture. Among them, the fibrous soy protein has a great effect on preventing shrinkage during cooking. It works well in hamburger beef patties.

(1) Improve nutritional value and replace lean meat. Soy protein is a full-price protein, which can be directly absorbed by the human body and is the main indispensable nutrient component of the human body. The protein content of 500g soy protein is equivalent to the protein content of 2~2.5kg pure lean pork, and the addition of meat products can also play a complementary role of animal protein and plant protein. There are many benefits of the complementarity of the two proteins. The albumin in meat and the soy protein in soy protein are all complete proteins with high physiological value. The two proteins complement each other and can improve the physiological value of the protein. In the processing of meat products, if the two proteins are matched properly and reasonably, the edible value can be greatly improved. In addition, soy protein isolate can also replace lean meat processed emulsified meat products.

(2) Improve the structure of meat products and the quality of meat products. The compactness of the structure of meat products and the homogeneity of the cut surface are mainly related to the viscosity between the tissues during processing. In the process of separation and extraction of soy protein, the viscosity of the protein increases due to acid-base treatment. As a result, the soy protein is added to meat products, and its tissue structure is greatly improved, which can make the internal structure of the product fine, good combination, elasticity, good slicing, cut and smooth and delicate, taste good, and improve the product’s quality. Tenderness increases the fresh aroma of the product, and can also maintain the original flavor of the product.

(3) Emulsification of fat The so-called emulsification is the process of dispersing two kinds of immiscible liquids (such as water and fat) in the form of droplets or balls in the other liquid evenly. Among them, the dispersed phase is called the dispersed phase, and the liquid containing the dispersed phase is called the continuous phase. Generally, the diameter of the dispersed phase droplets is between 0.1 and 50 μm. To maintain stable emulsification, an emulsifier must be present, because when fat and water are in contact, there is a greater surface tension between the two phases, and the emulsifier molecule has both a hydrophilic part and a hydrophobic part (that is, a hydrophilic part). The oil part), the hydrophilic part can be combined with water, and the lipophilic part can be combined with oil, so it can reduce the surface tension between the two phases and increase the stability of the emulsion. In the product raw materials, the dispersed phase is solid or liquid fat globules, and the continuous phase is an aqueous solution in which salt and protein are dissolved (or suspended).

In the processing of meat products, the soy protein isolate filled in the raw material of the product acts as an emulsifier in this system to promote the formation of oil-water emulsion and create a protective layer for the product. If the process is proper and the emulsification is good, the fat content in the product can reach 40%-50%, and 500g of soybean protein can emulsify about 2.5 kg of fat.

(4) Improve water retention. Because of the many polar groups in the long chain of soy protein structure, it can absorb water, and can retain water in the product to extend the shelf life. By comparison, among soy protein products, isolate soy protein has the highest water absorption, 3.5 to 4.0 times the dry weight, followed by concentrated soy protein, and tissue soy protein has better water absorption than soy flour. The water absorption of soy protein and the water retention of soy protein gel are related to pH. When the pH is 4.5, it absorbs water and retains the least water, and then as the pH is greater than or less than 4.5, the water absorption and water retention increase. This function is conducive to maintaining the gravy and helps the meat products maintain a good taste and flavor for the coming year for a long time.

(5) Strengthen the gel structure of meat products. The soy protein isolate molecules filled in the raw materials of the products combine with the free fat molecules among them to form a stable emulsification system. During the thermal processing of the product, the protein on the surface of the fat globules is denatured, and an elastic self-supporting gel is obtained, which tightly wraps the fat globules to form a uniform and elastic product tissue. If the heating temperature is 125°C, the gel is destroyed and the stable emulsification system is also destroyed, causing the product to produce oil.

At the same time, the gelatinity of soy protein can “solidify” the protein sol matrix into a stable structure with a certain mechanical strength, increase the chew feeling of food, and make elastic gel products.

(6) Increase product yield, reduce costs, and increase economic benefits. The addition of soybean protein in meat processing can not only improve product quality, but also increase product yield. For every 500g of soybean protein added, 2.5 kg or more of finished products can be added. As the production rate increases, the cost of the product will decrease, and the economic benefits will obviously increase. However, it should be noted that in a formula, soy protein is not added as much as possible, but it must be designed based on the specific circumstances of each formula, and a reasonable formula can achieve good results.

(1) Injection method For large (whole) ham products, it is usually added by injecting the pickling liquid, that is, soy protein isolate and soy protein concentrate are dissolved in the pickling liquid (salt water). It is added by injection, the protein is evenly distributed in the meat, and the effect is good. Usually protein products account for 6% to 11% of the pickling liquid.

(2) Emulsification method: For emulsified meat products, it is usually emulsified according to the ratio of 1 part of soy protein isolate, 4 parts of water, and 3 to 4 parts of fat, and then added to the product. Use other protein products and adjust the ratio of water and fat appropriately.

(3) Hydration method Take the soybean protein isolate product as an example, that is, 1 part of soybean protein isolate and 3 parts of water are fully hydrated to make the hydrated paste-like paste, and then add the product. Generally, high-speed disperser (emulsifier) ​​and chopping are used to complete protein hydration.

(4) Dry method That is to say, the protein products are added evenly in the state of dry materials at the beginning of the chopping, kneading, and mixing process, but the dry materials must be added to the meat products before the fat.

(5) Rehydration and deodorization method. This method is mainly applicable to textured soy protein concentrate and soy textured protein products. Before the protein is added to the meat product, the protein product is soaked in water at about 40°C for rehydration, and then washed and shaken. Dry for production.

The following issues should be paid attention to in the use of soy protein powder:

(L) Due to the high protein content of soybeans, the amount of lean meat is reduced, and the amount of fat is increased. To a certain extent, it will affect the color of the product. It can be supplemented with blood or allowed pigments. In addition, for the medium and low-end products, since the amount of lean meat is originally small, the amount of lean meat is relatively reduced after the addition of protein. It is best to add a small amount of meat flavoring to increase the internal flavor of the product.

(2) In the production of enema products, alkaline phosphate (STP) is used in most cases. When using soy protein isolate, acid phosphate (ASP) is best. Acid phosphate will reduce the ability of meat to bind water. . Therefore, when using ASP, it is best to add gluconolactone (GDL) at the same time to buffer the effect of ASP.

(3) Soy protein isolate has a certain covering effect on salt and seasonings, so it is necessary to pay attention to the seasonings to be added last, and adjust the amount of salt according to the situation.

(4) Protein products are used in low-temperature block meat products, and the temperature should meet the functional thermal processing requirements of protein products. The functionality of soy protein isolate and soy protein concentrate usually needs to be heated at 72°C (about 25 minutes). Therefore, low-temperature meat products should not be lower than 72°C when protein products are added, and the temperature should be processed for 25 minutes. In addition, this temperature can also make the carrageenan and corn starch added to the meat products become functional and completely gelatinized. If it is lower than this temperature, it will be difficult.

(5) When using the chopper (or mixer), the soy protein isolate must be fully chopped and chopped until thick and shiny, so that it can give full play to the emulsification effect. When emulsifying in the chopper, ice should be added. Crumbs, lower the temperature of the meat to enhance the emulsification effect and improve the quality of the product.

In meat processing, defatted soybean meal is sometimes used directly, and the amount generally accounts for 3% to 5% of the total feed. However, because of the peculiar beany flavor of soybeans, it is not easy to be removed during use, affecting the flavor and flavor of meat products. The quality is mainly used in low-grade enema products and famous meatballs, which can improve the water and oil retention functions of enema products and meatballs, and increase the protein content of the products. The quality of concentrated soy protein is higher than that of defatted soy protein, but the cost is higher than that of defatted soy protein powder, but it still has a beany flavor. Therefore, in the processing of meat products, soy protein isolate is mainly used. It is a good additive and ideal meat protein substitute in processed emulsified sausage products, and it is also a good protein additive in ham curing liquid. The use of soy protein isolate in meat product processing can not only improve the nutritional value of the product, but also reduce the cost. Therefore, soy protein isolate is widely used in meat product processing.