Abstract: Contents of ATP and related compounds, glycogen, and lactic acid, pH and protein component were analyzed in muscles of sea-farmed turbot Scophthalmusmaximus with body weight of 730-780 g which were slaughtered live on site by spinal cord cutting (non-stressed group), stored in ice for 7 days (fresh-locking group), struggling to die (asphyxial group), held in a recycled water tank at water temperature of (13.5±0.2)℃ and then slaughtered live on site by spinal cord cutting (stress-recovery group) and died on a live fish market (dying group) to investigate the effects of slaughtering methods, iced storage stability, and stress recovery on muscle quality of turbot. It was found that slaughtering methods had a crucial effect on the muscle quality, with muscular ATP concentration of 2.95 μmol/g in the turbot in non-stressed group and totally depleted in asphyxial group. The glycogen content was shown to be decreased from 5.28 mg/g to 3.06 mg/g and pH from 7.10 to 6.61 in the turbot, the turbot in keeping fresh group showing advanced in iced storage stability. In the early stage of iced storage, IMP accumulated rapidly with the degradation of ATP, with the maximum (9.81 μmol/g) on the 2th day, and stable at a high level(6.52 μmol/g) in 6 days of storage. The muscle ATP content was found to be only 1.31 μmol/g through post-harvest and transport treatment, increasing trend in 2nd day (with the maximal value of 4.26 μmol/g), the muscular glycogen content being also recovered from 4.49 mg/g at 7th to 8.17 mg/g, indicating that stress-recovery apparently led to relief stressed live fish. The quality of local market live and dying turbot was unsatisfactory compared with the control. The muscle ATP in live group only was 1.70 μmol/g, and the dying products was almost all degraded, with serious degradation of actin and myosin. It was concluded that, the turbot in keeping fresh group had superior muscle quality than local market products, live or dying, and that the turbot in stress-recovery group showed a positive effect on recovery of live fish from post-harvest stress.
2020, Vol. 35 
