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

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 ۸%. K-value of the fish climbed to more than ۵۰% at ۲۴ h. After ۲۸ h, K-value of the fish increased to ۷۳% and gradually increased till the end. The K۱-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 ۱.۳۷ and ۱.۳۳ mg/g muscle. Significant differences in the plasma cortisol concentration were found in the fish after ۲۴ and ۷۲ h live storage compared to the fish caught from the farm. The L* (lightness) value of the fish fillet from the farm, ۲۴ h, and ۷۲ h live storage was determined as ۶۲.۳۳, ۵۸.۱۲, and ۵۶.۲۱, respectively. After transporting the fish into the live seafood supply center, the total viable count was increased from ۲.۵۵ to ۴.۲۹ and ۵.۶۳ 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.

کلیدواژه ها:

Rigor mortis ، K-value ، Freshness ، Live supply center