Method of and apparatus for industrially obtaining rape core oil and rape protein concentrate from rapeseed

A method of processing grains of a rapeseed, the method comprising the steps of:

• dehulling the grains, wherein the grains are passed through a roller nip between dehulling rollers,
• separating a high-hull grain fraction from a low-hull grain fraction by sieving and/or air separation such that the hulls remaining in the low-hull grain fraction do not account for more than 4% by weight of the low-hull grain fraction,
• pressing cold-pressed rape core oil from the low-hull grain fraction,
• wherein a water content of the low-hull grain fraction is from 4 to 7% by weight,
• wherein a cake temperature in a press cake being generated is limited to 70° C., and
• wherein a first residual oil content is reduced to 18 to 28% by weight of a dry matter of the press cake,
• supplying pressurized steam to the press cake and subsequently expanding the press cake to form collets, wherein the steam is metered such that the press cake, under the influence of the steam, is temporarily heated up above 100° C. and the collets, after the expansion, have a temperature from 80° C. and 95° C.,
• extracting the collets with an organic solvent, wherein a second residual oil content is reduced to 2% by weight or less of a dry matter of the collets,
• separating a part of the collets prior to or after extracting the collets with the organic solvent, and adding the separated part of the collets to the low-hull grain fraction prior to the step of pressing.