天然および養殖ヒラメの死後硬直の進行の比較

抄録

Wild and cultured plaices were compared in terms of rigor-mortis progress during storage at 0° and 10°C. When spiked at the brain, both wild and cultured plaices exhibited the rigor-mortisonset after 3h at 0°C and after 6h at 10°C. They attained the full-rigor state after 21h at 0°C. At 10°C, wild plaice was relatively slower in rigor-mortis progress: It attained the full-rigor state after 32h while the cultured one had not yet done so. When killed while struggling and stored at 10°C, both types of fish set on rigor-mortis after 2h and attained the full-rigor state after 8h.
In the muscle, ATP degradation and lactate accumulation proceeded essentially in parallel to rigor-mortis progress. When spiked and stored at 0°C, both types of plaice showed a decrease of muscle ATP concentration from 6-7μmol/g at the start to less than 1μmol/g after 15-18h, the time when the lactate level reached the maximum of 35-40μmol/g. When stored at 10°C, both plaices showed corresponding levels of both compounds after 32h. When killed while struggling and stored at 10°C, both types of plaice showed a low level of ATP even immediately after death, the level further decreasing to less than 1μmol/g after 2-4h. They attained the maximum lactate accumulation of 35-40μmol/g after 6h.
It was concluded that rigor-mortis of plaice, either wild or cultured, was accelerated by both ice storage and by the death while struggling.