PROBLEM TO BE SOLVED: To provide an aqueous extraction, fractionation and enzymatic processing of oilseed materials for producing high valued products without containing low valued byproducts or waste components in a significant amount. SOLUTION: The oilseed materials are extracted at first by a solvent using an aqueous solvent and the aqueous extract is separated from remaining solids. The aqueous extract is dephytinized by being processed with a phytase enriched enzyme. The dephytinized extract is heat processed to be able to induce coagulation of proteins included in the extract. Subsequently, the precipitated proteins can be separated from the remaining liquid by solid-liquid separation. The method provides an efficient extraction and, also maintains the content of the proteins so that unextracted materials have good values of feed ingredients as protein-fibers for ruminant animals. Highly useful products can be produced by further treating the liquid extract after separating the precipitated proteins by a membrane filtration. COPYRIGHT: (C)2011,JPO&INPIT