Thermal Denaturation in Fish Muscle Proteins During Gelling: Effect of Spawning Condition

ABSTRACT We studied thermal denaturation of myofibrillar proteins from pre‐and post‐spawning hake by differential scanning calorimetry (DSC), and evaluated denaturation kinetics under both conditions. The denaturation enthalpies of all pre‐spawning fish muscle extracts were less than those from post‐spawning. The area under the DSC thermogram corresponding to myosin denaturation was smaller in myofibrillar extracts from pre‐spawning than from post‐spawning hake, while the areas corresponding to denaturation of actin were similar. Between 40 and 55°C the myosin denaturation rates were greater for post‐spawning than for pre‐spawning hake. Both entalphies and kinetic data indicated proteins of fish in a better biological condition (post‐spawned) denature more rapidly and completely.