Structural and functional study of soybean protein isolation

Soybean protein isolation (SPI), the main component in soybean, may become an important chemical resource for the preparation of environmentally friendly materials because it contains many reactive groups and has the merits of being renewable and biodegradable. As the composition and conformation of SPI may significantly influence its appropriate functional properties, the systematic elucidation of the relationship between the structures and properties of SPI could help scientists to develop the novel soybean protein materials with excellent properties in the future. Thus in the beginning of this article, the composition, the subunit structures of SPI and the separation of its major components, β-conglycinin (7S protein) and glycinin (US protein) are introduced. Then, the conformation studies under different conditions and the main physico-chemical properties of SPI, such as solubility and gelation property are summarized. At last, the applications of SPI as films, fibers and plastics in the material field are briefly reviewed.