Principles of Isolated soybean proteins

The basic principles of ISP production are simple. Soybean protein isolates are obtained by selective solubilisation of  the protein (e.g. alkaline extraction), followed by purification of the extract and precipitation of  the protein (e.g. by acidification to the isoelectric point). Isoelectric isolates are insoluble in water and have practically no functional features. They can  be converted to sodium, potassium or calcium proteinates by dissolving isoelectric  proteins in the appropriate base and spray-drying the solution. Sodium and potassium proteinates are water-soluble. They are used mainly  for their functional properties, such as emulsification or foaming. One of the  by-products of the  protein isolation process, the insoluble residue, is also commercialized for its remarkable water absorption capacity and as a source of dietary fibre.