Heat-induced denaturation and aggregation of actomyosin and myosin from yellowcheek carp during setting

Thermal inactivation kinetics of Ca2+-ATPase, changes in turbidity and rheological properties of actomyosin and myosin from yellowcheek carp during setting at different temperatures were investigated. Actomyosin and myosin setting at 40-45 °C exhibited greater extent and more rapid Ca2+-ATPase inactivation compared to at 25-30 °C. Formation of protein aggregates and three-dimensional network structures of actomyosin and myosin at 25-30 °C was far less than those at 40-45 °C. Thermal stability of actomyosin was higher than that of myosin as revealed by its higher activation energy for the inactivation of Ca2+-ATPase. Actomyosin and myosin also exhibited different dynamic rheological properties, especially when the setting temperatures were 40 and 45 °C.