The separation of a factor, which inhibits the degradation of myosin heavy chain in washed meat paste around 40°C, from the sarcoplasmic protein of fish meats was examined. The factor was extracted easily with water from meat. After the extract was mixed with DEAE-ion exchange resin, the factor was eluted with 0.1 M NaCl solution. On the other hand, when the extract was fractionated by ammonium sulfate, the factor was contained in a 50-70% saturated fraction. Then ammonium sulfate fractionation, after ion exchange treatment, gave an almost single peak chromatogram in gel filtration. The peak was 80, 000-90, 000 in molecular weight and showed no transglutaminase activity. Furthermore, this factor was separated from various kinds of fish meats, that is even from fish meat of which modori at 40°C is not induced by meat washing, which varies in modori behavior.
