A process for preparing a sunflower meal fraction F containing at least 50% by weight relative to the total dry weight of the fraction of proteins and 10% by weight relative to the total dry weight of the fraction or less of crude fibers comprising the following steps: a) preparation of a starting material by deagglomeration of a sunflower meal containing at least 30% by weight relative to the total dry weight of the meal of protein and having a moisture content of less than 12% into particles smaller than 5 mm; b) successive sieving of obtained starting material to obtain at least the following fractions: fraction F-b1 in which size of particles is of from d1 to d2; fraction F-b2 in which size of particles is of from d3 to d1; and fraction F-b3 in which size of particles is smaller than d3; c) deagglomeration and successive sieving of fraction F-b1 to obtain at least the following fractions: fraction F-c1 in which size of particles is of from d4 to d5; and fraction F-c2 in which size of particles is smaller than d4; d) air sieving of fractions F-b2 and F-c1 to obtain at least the following fractions: fraction F-d1 in which size of particles is greater than d6; fraction F-d2 in which size of particles is of from d7 to d6; and fraction F-d3 in which size of particles is smaller than d7; e) deagglomeration and successive sieving of fraction F-d1 to obtain a fraction F-e1 in which size of particles is smaller than d8; and/or fraction F-d2 to obtain a fraction F-e2 in which size of particles is smaller than d9; and/or fraction F-d3 to obtain a fraction F-e3 in which size of particles is smaller than d10; f) and mixing fractions F-b3, F-c2, F-e1 and/or F-e2 and/or F-e3 to obtain fraction F; wherein - d1 is of from 600 μm to 1600 μm; - d2 is of from 2000 μm to 5000 μm; - d3 is of from 150 μm to 500 μm; - d4 is of from 150 μm to 500 μm; - d5 is of from 600 μm to 1600 μm; - d6 is of from 800 μm to 1000 μm; - d7 is of from 500 μm to 750 μm; - d8 is of from 200 μm to 600 μm; - d9 is of from 200 μm to 600 μm; and - d10 is of from 200 μm to 600 μm. and wherein the size of particles corresponds to Dv90. a) preparation of a starting material by deagglomeration of a sunflower meal containing at least 30% by weight relative to the total dry weight of the meal of protein and having a moisture content of less than 12% into particles smaller than 5 mm; b) successive sieving of obtained starting material to obtain at least the following fractions: fraction F-b1 in which size of particles is of from d1 to d2; fraction F-b2 in which size of particles is of from d3 to d1; and fraction F-b3 in which size of particles is smaller than d3; fraction F-b1 in which size of particles is of from d1 to d2; fraction F-b2 in which size of particles is of from d3 to d1; and fraction F-b3 in which size of particles is smaller than d3; c) deagglomeration and successive sieving of fraction F-b1 to obtain at least the following fractions: fraction F-c1 in which size of particles is of from d4 to d5; and fraction F-c2 in which size of particles is smaller than d4; fraction F-c1 in which size of particles is of from d4 to d5; and fraction F-c2 in which size of particles is smaller than d4; d) air sieving of fractions F-b2 and F-c1 to obtain at least the following fractions: fraction F-d1 in which size of particles is greater than d6; fraction F-d2 in which size of particles is of from d7 to d6; and fraction F-d3 in which size of particles is smaller than d7; fraction F-d1 in which size of particles is greater than d6; fraction F-d2 in which size of particles is of from d7 to d6; and fraction F-d3 in which size of particles is smaller than d7; e) deagglomeration and successive sieving of fraction F-d1 to obtain a fraction F-e1 in which size of particles is smaller than d8; and/or fraction F-d2 to obtain a fraction F-e2 in which size of particles is smaller than d9; and/or fraction F-d3 to obtain a fraction F-e3 in which size of particles is smaller than d10; fraction F-d1 to obtain a fraction F-e1 in which size of particles is smaller than d8; and/or fraction F-d2 to obtain a fraction F-e2 in which size of particles is smaller than d9; and/or fraction F-d3 to obtain a fraction F-e3 in which size of particles is smaller than d10; f) and mixing fractions F-b3, F-c2, F-e1 and/or F-e2 and/or F-e3 to obtain fraction F; wherein - d1 is of from 600 μm to 1600 μm; - d2 is of from 2000 μm to 5000 μm; - d3 is of from 150 μm to 500 μm; - d4 is of from 150 μm to 500 μm; - d5 is of from 600 μm to 1600 μm; - d6 is of from 800 μm to 1000 μm; - d7 is of from 500 μm to 750 μm; - d8 is of from 200 μm to 600 μm; - d9 is of from 200 μm to 600 μm; and - d10 is of from 200 μm to 600 μm. and wherein the size of particles corresponds to Dv90. - d1 is of from 600 μm to 1600 μm; - d2 is of from 2000 μm to 5000 μm; - d3 is of from 150 μm to 500 μm; - d4 is of from 150 μm to 500 μm; - d5 is of from 600 μm to 1600 μm; - d6 is of from 800 μm to 1000 μm; - d7 is of from 500 μm to 750 μm; - d8 is of from 200 μm to 600 μm; - d9 is of from 200 μm to 600 μm; and - d10 is of from 200 μm to 600 μm.