Abstract: There is described a process and apparatus for treating oleaginous seed materials, such as soybean flakes with an extraction solvent, which includes an extraction zone, a desolventizing zone, and a miscella treating zone. In the extraction zone, the oleaginous seed material is subjected to concurrent contact with a carbohydrate-selective extraction solvent in a plurality of extraction vessels arranged in countercurrent fluid relationship therebetween with the expression of treated solids being effected after each extraction. The expressed solids from the last extracting vessel are passed to a desolventizing zone wherein residual solvent is vaporized by the respective indirect and direct contact with a heat transfer medium, such as steam, to produce a protein concentrate having a concentration (moisture free basis) of proteinaceous matter of at least about 70% by weight (6.25 times the total nitrogen content by the Kjeldahl method).