1.1 The production principle of textured soy protein
Add low-temperature defatted soybean meal, high-temperature defatted soybean meal, cold-pressed soybean meal, concentrated protein, separated protein and other raw materials into a certain amount of water and additives, and mix them evenly, by mechanical or chemical methods, forcibly heating, pressurizing, and extrusion molding, Change the arrangement of protein molecules to produce a tissue structure in the same direction, and at the same time solidify to form fibrous protein that is soy tissue protein. The protein in the raw material can be undenatured or denatured. In the extruder, after the protein is pretreated, under the action of high temperature, high pressure and strong shearing force, the protein is denatured, the highly regular spatial arrangement inside the molecule changes, the secondary bonds in the protein molecule are destroyed, and the peptide bond structure Loose, and then form relatively linear protein molecular chains. These relatively linear protein molecular chains become more free at a certain temperature and moisture content, so that directional recombination is more likely to occur. In the process of protein denaturation, Affected by the directional force, the protein molecules are arranged linearly and organized along the flow direction, and further solidify to form a fleshy fiber structure. Finally, the temperature and pressure are drastically changed through the mold to produce a certain expansion to form porous tissue protein.
1.2 Main production process requirements
(1 Selection of raw materials: raw materials have a greater impact on the puffing technology, so the selection of raw materials is very important. Generally, it is required that the protein content of the raw materials is greater than 50%, the fat content is less than 1.5%, the fiber content is less than 3.5%, the moisture content is less than 10%, and the nitrogen The solubility coefficient (NSI) is about 60%.
(2 PH adjustment: The pH value of the raw material should be around 7.0. When the pH value is lower than 5, the degree of organization will drop sharply, and it will not even expand; with the increase of the pH value, the product will be slightly alkaline. The quality of the organization is better, and the shape is neat. When the PH value is above 8, the product becomes brittle and hard, and produces peculiar smell and toxic substances, and the color is poor.
(3 Temperature: temperature and material-water ratio temperature at 190℃, material-water ratio 20:13-15 conditions, the water absorption rate is the largest, the shear force is the largest, the higher the water absorption rate, the higher the elasticity and toughness of the soy tissue protein; The greater the shearing force, the better the degree of organization, and the better the product forming degree, the bright yellow color is uniform.