Post-mortem quality changes in rainbow trout (Oncorhynchus mykiss) during live storage


1 Department of Fisheries, Science and Research Branch, Islamic Azad University, Tehran, Iran.

2 Department of Fisheries Science, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.



This study aimed to examine the quality changes of rainbow trout (Oncorhynchus mykiss) caught from the farm and live supply center at different times. Rigor mortis, ATP-related components, K-value, and blood parameters of rainbow trout were monitored during storage in the live supply center of rainbow trout. The progress of rigor mortis was accompanied by an increase in storage hours. The initial K-value of fish in live storage was lower than 8%. K-value of the fish climbed to more than 50% at 24 h. After 28 h, K-value of the fish increased to 73% and gradually increased till the end. The K1-value, G-value, P-value, and Fr-value were increased during storage time. The initial glycogen content in the individuals from the farm and live storage were 1.37 and 1.33 mg/g muscle. Significant differences in the plasma cortisol concentration were found in the fish after 24 and 72 h live storage compared to the fish caught from the farm. The L* (lightness) value of the fish fillet from the farm, 24 h, and 72 h live storage was determined as 62.33, 58.12, and 56.21, respectively. After transporting the fish into the live seafood supply center, the total viable count was increased from 2.55 to 4.29 and 5.63 log CFU/ g. These results suggested that the measurement of quality indexes has a great potential for predicting the freshness of rainbow trout during live storage in seafood supply centers.