A press cake or oil cake is the solids remaining after pressing something to extract the liquids. their most common use is in animal feed. some foods whose processing creates press cakes are olives for olive oil (pomace), peanuts for peanut oil, coconut flesh for coconut cream and milk (sapal), grapes for wine (pomace), apples for cider (pomace), and soybeans for soy milk (used to make tofu) (this is called soy pulp) or oil. other common press cakes come from flax seed (linseed), cottonseed, and sunflower seeds. however, some specific kinds may be toxic, and are rather used as fertilizer, for example cottonseed contains a toxic pigment, gossypol, that must be removed before processing.

Source: Wikipedia