Introduction of soy protein isolate
Abstract: Soy protein isolate is a full-price protein food additive produced from low-temperature desolubilized soybean meal. The protein content of soy protein isolate is more than 90%, there are nearly 20 kinds of amino acids, and it contains essential amino acids. It is rich in nutrition and does not contain cholesterol. It is one of the few varieties of plant protein that can replace animal protein.
Keywords: Soy protein isolate, application, amino acid
The United States is the first country in the world to conduct research and industrial production of soy protein isolate (SPI). It began research in the 1940s and developed soy protein isolate in the 1950s. It started production in the 1960s, and its production technology gradually became more and more in the 1970s. For perfection and maturity. The international protein isolate market is basically monopolized and controlled by the United States. In addition, Japan, Germany, Brazil and other countries also occupy a certain share in the international market. In 1998, the world’s output of soy protein isolate was about 700,000 tons, and the United States produced about 350,000 tons, accounting for 50%. my country began to study the production and application technology of soy protein isolate in the 1970s, and began to produce soy protein isolate in the early 1980s. The production and development of soybean protein isolate in our country are closely related to the rapid development and increase in demand of the food industry, especially meat products (such as Western-style ham). By 1998, the domestic demand for soy protein was nearly 30,000 tons. So far, there are about 26 soybean protein isolate production enterprises in China that have been established or are under construction, with a total design capacity of nearly 30,000 tons. However, in 1998, the total amount of soy protein isolate produced by domestic manufacturers and entered the market was only about 11,000 tons. Nearly 2/3 of the market was still occupied by the products of American Polytech International and ADM, which caused a serious impact on the domestic soy protein isolate market. Bring a lot of pressure to the enterprise.
Existing form of soy protein isolate
Soy protein is a high molecular organic polymer composed of a series of amino acids through peptide bonds. It is mainly composed of albumin and globulin, of which albumin accounts for about 5% and globulin accounts for about 90%.
There are two classification methods for the existence of soy protein isolate. One is the classification method based on the sedimentation index. After high-speed centrifugation, soybean protein is divided into 4 levels according to the centrifugal sedimentation index, 2S, 7S, 11S, and 15S. Among them, 7S and 11S are the main components, which are also the main components of globulin, accounting for about 70% of the total protein. The functional properties of soy protein isolate play a very important leading role. The other is a classification based on immunological characteristics. Can be divided into a-concentrated globulin (about 15%), 13-concentrated globulin (about 28%), ^y-concentrated globulin (about 3%), soluble globulin (about 40%) 4 class.
Emulsification: Soy protein isolate is a surface active agent, which can reduce the surface tension of water and oil as well as the surface tension of water and air. Easily form a stable emulsion. In the production of grilled food, frozen food and soup food, adding soybean protein isolate as emulsifier can make the product state stable.
Hydration: Soy protein isolate contains many polar groups along its peptide chain backbone, so it has water absorption, water retention and swelling properties. The water absorption of protein isolate is much stronger than protein concentrate, and it is hardly affected by temperature. The protein isolate has the ability to retain water during processing, and the highest water retention capacity is 14g water/g protein.
Oil absorption: When protein isolate is added to meat products, it can form emulsion and gel matrix to prevent fat from moving to the surface, thus it plays a role in promoting fat absorption or fat binding, and can reduce the loss of fat and juice during meat processing. Help maintain the stability of the shape, the oil absorption rate of the protein isolate is 154%.
Gelation: It makes the protein isolate have higher viscosity, plasticity and elasticity. It can be used as a carrier for water, as well as a carrier for flavors, sugars and other complexes, which is extremely beneficial to food processing.
Foaming property: Among soy protein, the foaming property of isolate protein is the best. Utilizing the foaming property of soy protein can give food a loose structure and good taste.
Conjunctival: When the meat is chopped, it is coated with a mixture of protein isolate and egg protein on the surface of the fiber to form a film, which is easy to dry, can prevent the odor from being lost, is conducive to the rehydration process, and provides reasonable rehydration products structure.
Meat products: adding soy protein isolate to higher-grade meat products not only improves the texture and flavor of meat products, but also increases the protein content and strengthens vitamins. Because of its strong functionality, the amount of 2~5% can retain water, fat, prevent segregation of gravy, improve quality, and improve taste. The protein isolate injection is injected into meat like ham. After the meat is processed, the percentage of ham can be increased by 20%. In hot pot products, tribute balls, pissing beef balls, chicken breast balls, Minnan fragrant meat, sweet and not spicy, tempura, flowering intestines, kiss intestines, Taiwan roast Intestines, hot dog sausages, meat skewers, Sichuan-flavored chicken fillet, flesh-and-blood joints, colonel’s chicken nuggets, McLean chicken, Orleans roast duck embryo, conditioning wing roots, marinated drumsticks, luncheon meat, sandwiches and other meat products are processed, soy protein isolate The addition of soy protein can make the structure of the product more perfect. Soy protein isolate and Bangli’s vegetarian meat powder can be added at the same time. Nutrition is more scientific.
Surimi products: Isolate protein used in deep-fried fish cake, tofu, fish steak, fish plate, fish roll, conch ball, north sea fin, crab steak, crab stick, scallop, grilled sausage, shrimp flavored sausage, abalone sausage, sea cucumber hot pot sausage, fish sausage, fish rice flower, with 20~ 40% fish meat.
Dairy products: Soy protein isolate is used to replace milk powder, non-dairy beverages and various forms of milk products. It has comprehensive nutrition and does not contain cholesterol. It is a food substitute for milk. Soy protein isolate is used in the production of ice cream instead of skimmed milk powder, which can improve the emulsification properties of ice cream, delay the crystallization of lactose, and prevent the phenomenon of “sanding”.
Noodle products: Soy protein isolate is used to replace milk powder, non-dairy beverages and various forms of milk products. It has comprehensive nutrition and does not contain cholesterol. It is a food substitute for milk. Soy protein isolate is used in the production of ice cream instead of skimmed milk powder, which can improve the emulsification properties of ice cream, delay the crystallization of lactose, and prevent the phenomenon of “sanding”.
Soy protein isolate can also be used in beverages, nutritious foods, fermented foods and other food industries. It has a unique effect on improving food quality, increasing nutrition, reducing serum cholesterol, and preventing heart and cerebrovascular diseases.
High protein: Whether for vegetarians or ordinary people, soy protein isolate powder is the perfect high-quality protein supplement.
Low-fat: For dieters who need a low-calorie diet, replacing part of the protein in the diet with soy protein not only reduces the intake of cholesterol and saturated fat, but also achieves a balanced nutritional intake.
Increase calcium: Soy protein can prevent urinary calcium loss, promote bone health, and reduce the risk of osteoporosis.
Cholesterol reduction: Studies have shown that taking 25g of soy protein daily can effectively reduce the content of total cholesterol and low-density lipoprotein cholesterol in the human blood, thereby reducing the risk of heart disease.