FIELD: food technology. SUBSTANCE: method involves the preparing food addition by extraction of the prepared animal raw (milled frozen organs and tissue of mammalian) using 1-2.5% sodium carbonate solution at pH = 10.4-10.8 for 2-4 h with addition of 0.1-0.5% magnesium chloride. Ratio of volumes of extractable tissue and soda solution is (1:8)-(1:20). Then deposit is separated by filtration or centrifugation followed by extract acidification to pH = 3.8-5.5, inert matters removing, precipitate washing with organic solvents and precipitate drying at temperature 55 C, not above. EFFECT: improved method of preparing. 5 tbl
