High temperature, extruding is the main technique for making textured soybean protein. The material with a high degree of protein (at least 70% content of protein; In Sulian, e use the isolate protein with the protein content more than 90%) we use the isolate protein with the protein content more than 90%) ）will receive shear force and friction force in extruding machine which will destroy the hydrogen bond, VDW, ionic bond, and disulfide bond that hold out the tertiary structure of protein. With the break down of the protein tertiary structure, there comes into the linear protein molecular chain which will turn to free form at certain temperature and moisture content.

Along with the constant shear force and friction force, more and more linear protein molecular chain emerged. The adjacent linear protein molecular attracted with each other and tend to combine together. When the material extruded through mold, the higher shear force and directional flow will prompt the protein molecular be linear, fibrous and in linear arrangement. Protein extruded in this way forms out the fibrous and porous structured drawing protein. The higher protein level brings about a strong fiber texture.