ATP and Glycogen Content Related to Gaping inPre RigorCod (Gadus morhua)Frozen in Blocks at Sea

Abstract

The ratio of pre rigor fish in frozen cod blocks was monitored. The fish (264 from 11 batches) was classified as either in rigor and post rigor or as pre rigor according to ATP and glycogen content. The average amount of pre rigor fish was found to be between 10 and 57% depending upon the criteria for determination of rigor state in frozen cod. The percentage of pre rigor fish in individual batches varied from a few percent to 100%.Principal component analysis of sensory and chemical data showed a correlation between gaping of the thawed fillet and the contents of ATP and glycogen. In conclusion, fillets from frozen whole fish with high content of ATP and glycogen (pre rigor) were more likely to gape when the fish was thawed at a high temperature compared to fish with high content of Ino and Hx (post rigor).