SUMMARYSlices of beef were heated to 130°, 150° and 195° F, irradiated at 0.1 and 5.0 megarads and stored at 34° F. The effect of these variables on free amino nitrogen, total soluble nitrogen and TCA‐soluble nitrogen was determined at 15‐day intervals during the 60‐day storage period. Increases in heating temperature reduced the rate of release of TSN and TCA‐soluble fractions. Amino nitrogen was reduced only at highest temperature employed. Irradiation increased the rate of release of these fractions. The release of amino nitrogen began immediately upon storage of raw beef. Major amounts of TSN were not released until after 15 days storage and TCA‐soluble nitrogen not until after 45 days storage. This suggests successive fragmentation of the initially