Studies On The Dynamic Viscoelasticity And Microstructure Of Extruded Flaxseed Meal

Extrusion texturization processing technology is a kind of high temperature and high pressure food processing technology,which is highly efficient by crushing,kneading,mixing,curing,sterilization,pre-drying and forming.The extrusion allows the product to obtain a certain shape and organizational form;also,the product which is similar to the fibrous structure is due to the texture and structure recombination of the protein.Nowadays,the procedure of plant protein organization and its mechanism of structure formation are the hot spot of researchers at home and abroad.A lot of research is still confined to macroscopic texture and process parameters;whereas the mechanism of the microstructure change of the fibrous three-dimensional complex formed reorganization is not clear.Moreover,there are still limitations in revealing the black box phenomenon of extrusion process.The dynamic rheology and fractal theory are introduced into this project.Firstly,a lot of basic experiments were carried out to study the quality control and characterization of extruded protein,and a multi-response optimization scheme was presented to explain the integrated physicochemical properties of the protein.This scheme preliminarily explained that the blending system forming stable solid polymer during extrusion.Based on the above factors,the dynamic rheological evolution of the extrusion process was studied and the dynamic mechanical model of the extruded product was systematically established.Furthermore,a widely used relationship between the extrusion parameters and dynamic rheological and mechanical model was established.The effects of thermal effects,shear force and compositional changes on the model correction were investigated.The results show that the rheological properties of the plant protein in the extrusion process can effectively feedback the structural changes and texture recombination of this typical non-Newtonian fluid.The microstructure of plant protein products were analyzed by thermodynamics,crystallinity,and infrared spectroscopy combined with confocal microscopy.The fractal theory is also introduced to really describe the objective micro structure of organized proteins by using fractal dimension,thereby getting out of the traditional one-dimensional line,two-dimensional surface,and three-dimensional space-time.Also,this project has made important progress in theoretical research;it is of important scientific significance to explain the process of textural reorganization of plant protein in extruder and reveal the phenomenon of black box.