Viscosity and Stability of Structural Proteins of Irradiated Indian Mackerel

Fresh Indian mackerel (Rastrelliger kanagurta) was exposed to gamma radiation at dosages of 0,1.5 and 3 kGy. The meat was collected and subjected to a four-step washing treatment. Homogenates of the washed meat in cold (<10°C) water exhibited apparent viscosity, which was dependent upon protein concentration. Warming the homogenate to 45°C or reduction of its pH to 3.5 by acetic acid decreased the viscosity. Proteins in the low-viscosity dispersion were stable to heating at 100°C while incorporation of NaCl at 5 mM prior to heating resulted in protein precipitation. Gamma irradiation did not affect the viscosity, solubility or stability of the muscle proteins in water.