Effect of Cold-CO₂ Anesthesia on Postmortem Levels of ATP-Related Compounds, pH, and Glycogen in Carp Muscle

Abstract

Postmortem changes in the levels of ATP-related compounds were investigated in the muscle of carp which were kept in a container for 10h at 14°C and Pco₂=80mmHg (cold-CO₂ group), at 14°C under bubbling pure O₂ gas (14°C-O₂ group), or at 23°C under bubbling pure O₂ gas (23°C-O₂ group), carp which were allowed to recover from cold-CO₂ anesthesia before death (CO₂-recovery group), and carp netted from a rearing tank and decapitated immediately (control group). The changes in glycogen and pH were also measured in the muscle of cold-CO₂, CO₂-recovery, and control groups. The initial ATP, pH, and glycogen levels were low, while the IMP level was high in the cold-CO₂ group compared with that in the control group. The carp anesthetized with cold-CO₂ seemed to be in a different metabolic state. The ATP degradation rate was rapid at an early stage of storage, while the freshness index (K value) was high in the cold-CO₂ group during storage compared with those in the control group. In the 14°C-O₂ and 23°C-O₂ groups, the postmortem levels of ATP-related compounds showed little difference from those in the control group. In the CO₂-recovery group, the postmortem levels of ATP-related compounds, pH, glycogen, and K value also showed little difference from those in the control group. The meat quality of the carp treated with cold-CO₂ anesthesia was unaffected when the carp was allowed to recover from anesthesia.