Delayed influence of quality-determination-period emersion on the recovery of live scallop (Patinopecten yessoensis) re-immersed

To explore the delayed influence of post-harvest treatment on the quality change of live scallops, the experiment was performed in two post-harvest stages, including a quality determination period (QDP) corresponding to on-board handling and post quality determination period (P-QDP) corresponding to land-based treatment. There were three chilled-emersing treatments of different duration during the QDP: 12 h(E12), 24 h(E24) and 48 h(E48). In the P-QDP scallops are re-immersed into sea water for 24 h (E12'nd E24'). The quality of live scallops was measured by mass loss rate, survival rate, pH, glycogen content, ATP and ATP-related compounds, AEC value and SOD activity. The results show that the quality of QDP scallops declined in different degrees: E48 presented a 100% mortality and the survival rate in 24 h was 100%. Glycogen content declined sharply from 18.95 (Initial) to 14.66 mg/g (12 h). The QDP had a delayed influence on live scallop in the P-QDP: all indicators show E12' and E24' can recover temporarily but the shelf-life of E12' is superior to E24'. The study shows that there is a quality determination period post-harvest during which the handling has delayed influence on the recovery of live scallop after re-immersing. The post-harvest scallops can be recovered and 12 h treatment in the QDP is helpful for recovery. If treatment conditions are effectively chosen during the QDP, live scallops would have better recovery after re-immersing, otherwise, if overstressed during the early post-harvest stage i.e. QDP, even if indicators are good by the end of the period, depletion would continue in the P-QDP, affecting vitality and shelf-life of live products.