PURPOSE: To prepare a fat-rich mixture having high oxidation resistance, by compounding protein-rich powder derived from the crops of leguminous plants and gramineous plants, with the auto-digestion product of animal tissue, and if necessary, oils and fats, or fatty acids.

CONSTITUTION: A fat-rich powdery mixture is prepared by drying the mixture of (A) protein-rich powder derived from the crop of leguminous plant, e.g. defatted soybean flour, (B) protein-rich powder derived from the crop of gramineous plant, e.g. defatted corn gluten, wheat bran, defatted rice bran, etc., (C) the autodigestion liquid obtained from the tissue of fish, crustaceans, shellfish, mollusks, etc., and if necessary, (D) oils or fats such as butter or fatty acids such as linoleic acid.