The shelling of nuts or seeds. “Decorticated” was at one time much used as a description of wholemeal, from which the coarser bran particles had been removed. Such meal was distinguished from the ordinary as “decorticated wheatmeal”. This decription has fallen into disuse.
From The Baker’s ABC by John Kirkland, formerly Head Teacher of National School of Baking, published 1927 by Gresham