Pressure-induced denaturation of muscle proteins and its prevention by sugars and polyols

Muscle tissues from four fish species (poikilotherms) that originated from different habitats and from beef (homeotherm) were subjected to pressures, ranging from 50 to 200 MPa, with or without pressure-shift freezing, The extent of denaturation was measured as residual Ca2+-ATPase activity. The ability of various sugars and polyols to protect the proteins from denaturation was also evaluated. Stability of proteins from the different species seemed to vary primarily according to body/habitat temperature. Sugars and polyols increased muscle protein stability, and sorbitol was the most effective. The degree of protection was, however, markedly reduced during pressure-assisted freezing.