Disclosed is a method comprising irradiating edible residues, the method comprising: irradiating, with electron beam radiation, edible residues that have been produced as a by-product of an ethanol manufacturing process, wherein the edible residues comprise 5 lignin, xylose and minerals, wherein the edible residues contain an antibiotic, and irradiating is performed under conditions selected to inactivate or destroy the antibiotic.
