Physical Properties and Structure of Soybean Fibrous Protein Prepared by "Gravity Dropping Method"

Abstract

Physical properties and fine structure were analyzed on soybean fibrous protein prepared by "gravity dropping method", which forms the fibrous protein by dropping protein dope solution into a coagulation bath through nozzles under gravity. The fibrous protein thus prepared showed higher water holding capacity and lower tensile stress and energy than a soybean fibrous protein commercially available. Cross-section of the fibrous protein had unique dual structure; the outer-layer was observed around half of the cross-section. The structure seemed to be closely related to the processing method, particularly coagulation process. Sausages were prepared by blending with the fibrous protein (A) or the commercial one (B) and pork to compare certain physical properties with those of control sausage blended with pork alone (C). Although no statistical significance was found among the three in terms of breaking energy with bending test, bending force and viscosity index of both A and B were higher than those of C, suggesting the occurrence of interaction between soybean and meat proteins. Additionally it seemed that not only the physical properties of the fibrous protein itself but also other factors such as size, length and pretreatments affected on the physical properties of sausages blended with the fibrous proteins.