Protein Extractability and Thermally Induced Gelation Properties of Myofibrils Isolated from Pre- and Postrigor Chicken Muscles

Purified chicken myofibrils were suspended in 0.6M NaCl at various pH values to study gelation properties of the myofibrils. Postrigor breast myofibrils showed a greater protein extractability and gel strength than prerigor breast myofibrils, but the reverse was found for leg myofibrils. Salt-soluble protein was least extractable at pH 5.50 for both breast and leg myofibrils. The pH for optimum gelation, indicated by increased penetration force, was 6.00 for breast and 5.50 for leg myofibrils. Heating at 1°C/min from 20 to 70°C produced stronger breast but weaker leg myofibril gels than isothermal heating at 70°C for 20 min. Muscle rigor state showed a greater effect on protein extractability and gel strength for breast myofibrils than for leg myofibrils.