Soy protein products have solubility, cohesion, water retention and water absorption, viscosity, gelation, adhesion, elasticity, emulsification and emulsification stability, fat absorption, foam, extensibility, block or layer Properties, combinability with fragrances, toning properties, etc. Some of these functional properties are common, and some are unique to individual soy protein products.
The functional characteristics are related to the different processing methods of soy protein products. According to various functional characteristics, select suitable soybean protein products in food processing to improve food quality.
In defatted soy flour, the protein content is more than 50%, the concentrated soy protein is 70%, and the isolated soy protein is more than 90%. The use of soy protein products in food processing is not based on the nutritional value of soy protein products, but mainly uses its functional properties.
- Defatted soy flour: Soy flour has two types: coarse and fine. Semolina is also called bean grits. From 10 to 80 meshes can be divided into 3 grades. The fine powder is below 80 mesh. The technological process is: soybean cleaning, dehulling, oil extraction, low-temperature desolventization, soybean meal crushing, sieving and grading. The fine powder is used as a finished product, and the bean grits are used in brewing.
- Concentrated soybean protein: mix soybean powder with less than 100 mesh with water, add acid to adjust the pH to 4.5, and stir to precipitate the soybean protein and fiber. Separate soluble carbohydrates, inorganic salts and low molecular weight proteins. The finished product is obtained by drying the precipitate. The low-temperature defatted soy flour can also be washed with an alcohol solution with a concentration of 50 to 70% to remove soluble components and part of the alcohol-soluble protein, and then volatilize to remove the alcohol. After drying, the finished product is obtained.
- Soy protein isolate: Add water or lye to the low-temperature desolubilized soy flour to extract the soluble matter together with the soy protein, and filter to remove the insoluble matter. Add acid to adjust the pH of the extract to about 4.5, and the protein precipitates and separates from the soluble components. The precipitate is washed with water and dried to obtain the finished product.
Use the above soy protein products as raw materials to obtain other foods after further processing
- Use edible soy flour, concentrated soy protein or separated soy protein as the main material, add some other materials, and make tissue protein after extrusion, which can be used as meat additives or meat-like products.
- Heating defatted soy flour, concentrated soy protein or isolated soy protein into soy protein peptone can be used in meatless enema, aquatic products and meat fillings.
- The separated soybean protein is processed into sponge protein, which has high water holding capacity and good mixing effect with livestock meat.
- The separated soybean protein is processed into fibrin, which can be processed into imitation meat products after bonding.
- Various soy protein products can be used in bakery products, meat products, breakfast foods, infant foods, protein drinks, etc. due to their different functional characteristics to improve the quality of food.