Mechanism And Quantitative Characterization Of Wheat Gluten Protein Extrusion Formation

Glutenin is a nutrient-rich,cholesterol-free,high quality and inexpensive vegetable protein produced by deep processing of wheat.The application of high-protein meat-based foods produced by high-moisture extrusion tissue technology using gluten as a raw material or additive has an important role in improving the nutritional structure of the national diet and improving the national constitution.However,due to the complexity of the extrusion mechanism of high-moisture textured gluten protein,the diversity and inconsistency of product evaluation standards limit the large-scale industrial development of textured protein meat products.Test the mechanical properties of the textured gluten protein product and observe its microstructural properties,and then find the new experimental method and product for quantitatively characterizing the anisotropy of the textured structure by the relationship between the mechanical properties and the microstructure analysis.The evaluation index has laid a solid theoretical foundation and technical basis for establishing an objective standard for scientific evaluation of the degree of texturization of gluten protein extruded products.At the same time,through the experimental results,the extrusion molding mechanism of the organized protein product is described from the mechanical point of view,and the theoretical basis for controlling the physical conditions of protein denaturation in the process of extrusion texturization is provided to optimize and improve extrusion process level and quality of wheat gluten protein products.In this project,the textured gluten protein was studied,and the mechanism of extrusion texturizing and the mechanical properties of texturized gluten protein extrusion product were studied in detail.The specific research contents and results are as follows:(1)Scanning electron microscopy system was used to observe the microstructure of the lateral and longitudinal sections of the texturized gluten protein products of three different flour addition contents,and fully understood the fiber arrangement and layered structure of the texturized protein.(2)The mechanical properties of the gluten protein texturized products in the lateral and longitudinal directions were determined by a series of mechanical tests(stretching,shearing,tearing,biaxial stretching and fiber drawing).And according to the comparison of mechanical properties and microstructure analysis results in different directions,a new method for characterizing the degree of anisotropy of the microstructured structure is found.(3)Combining the fiber properties and the uniaxial tensile properties of the product,the stiffness and strength formulas of the composite theory are used to solve the fiber content and the matrix stiffness,and the fiber forming form of the product is analyzed by these indexes.From the perspective of mechanics and materials science,the reorientation and pressure-welding hypothesis of wheat gluten protein microfibers in extrusion cooling die is proposed,and explains the evolution of wheat gluten protein network structure in various stages of extrusion process.