There are two ways to classify the existing forms of soy protein isolate, one is based on sedimentation index. After high-speed centrifugation, soybean protein can be divided into four grades according to the centrifugal sedimentation index: 2S, 7S, 1 1 S, 15S***4 *, of which 7S and 1 1S are the main components, accounting for about 70% of globulin. The other is classification based on immunological characteristics. It can be divided into four categories: A- concentrated globulin (about 15%), 13- concentrated globulin (about 28%), Y- concentrated globulin (about 3%) and soluble globulin (about 40%).
Functional performance
emulsibility
Soy protein isolate is a surfactant, which can reduce the surface tension of water and oil, and water and air. It is easy to form stable emulsion. In the production of baked food, frozen food and soup food, adding soy protein isolate as emulsifier can stabilize the product state.
hydratability
Soybean protein isolate contains many polar groups along its peptide chain skeleton, so it has water absorption, water retention and expansibility. The water absorption of isolated protein is much stronger than that of concentrated protein, and it is almost unaffected by temperature. The isolated protein also has water retention capacity during processing, and its high water retention capacity is 14g water /g protein.
oil absorption
When added to meat products, the isolated protein can form emulsion and gel matrix to prevent fat from moving to the surface, thus promoting fat absorption or fat combination, reducing the loss of fat and juice during the processing of meat products, and helping to maintain the stability of appearance. The oil absorption rate of the protein isolate was 154%.
gelatineous
It makes the separated protein have high viscosity, plasticity and elasticity, and can be used as the carrier of water, essence, sugar and other compounds, which is very beneficial to food processing.
Foamability
In soybean protein, isolated protein has good foaming performance. Using the foaming characteristics of soybean protein, food can be endowed with loose structure and good taste.
Conjunctival
When the meat is chopped, the separated mixture of protein and egg protein is wrapped on the fiber surface to form a film, which is easy to dry, can prevent odor loss, is beneficial to the rehydration process, and provides a reasonable structure for the reconstituted aquatic products.
use
meat products
Adding soy protein isolate to high-grade meat products can not only improve the texture and flavor of meat products, but also increase the content of protein and strengthen vitamins. Because of its strong functionality, the dosage of 2-5% can keep water and fat, prevent the separation of gravy and improve the quality and taste. The separated protein injection is injected into the meat like ham, and then the meat is treated, and the yield of ham can be increased by 20%. Among the hot pot products, Gongwan, Pistachio Beef Pill, Chicken Breast Pill, Minnan Fragrant Meat, Tempura, Tempura and so on.