Patent ID: 7300681

Claim:
A method for producing protein preparations having essentially constant functional properties for applications within a broad pH range from about pH 3 to pH 10 by means of extraction from a starting product which contains protein, said starting product including a member selected from the group consisting of a legume, a grain and an oilseed, the method comprising the following process steps: a) comminution of the starting product and addition of said comminuted starting product to a first acidic solvent in order to obtain an acidic suspension, b) separation of said acidic suspension into a raffinate I and an extract I by way of solid/liquid separation at a temperature between 5° C. and 70° C., c) addition of said raffinate I to a base solvent in order to obtain a base suspension, d) separation of said base suspension into a raffinate II and an extract II by way of solid/liquid separation, e) acidification of said extract II and precipitation of the proteins from said acidified extract II in the form of protein curd in order to obtain an excess liquid, f) separation of said excess liquid by way of solid/liquid separation in order to obtain said excess liquid having a protein content of >80% by dry weight, g) addition of said excess liquid to a residue, which is produced by separation of said extract I using a membrane separation process in order to obtain the residue containing the protein preparations having desired properties, and said excess liquid is used as washing liquid within the scope of diafiltration, and h) washing the proteins having desired properties obtained in said residue.