Challenges of effective chilling of Atlantic salmon in refrigerated sea water: field tests

Abstract

This papers is summing up main challenges which occur at large-scale industrial slaughter houses when chilling Atlantic salmon by refrigerated sea water (RSW). The study includes strategies of efficient chilling in 100 m 3 spiral tanks based on the field tests. Analysis showed high density of fish in a chilling tank and low refrigerated sea water flow lead to non-uniform temperature distribution in the tank. Temperature at the surface of the fish can exceed values of RSW outlet temperature, which increases the chilling time, reduces efficiency of the process and limits capacity of equipment. The chilling index can vary from 66 to 108% for the same type of chilling tank with respect to operation parameters. Agitation of fish in the chilling tank increases chilling efficiency up to 87.9 %. The limited time of fish holding in the chilling tank (75-100 min) was not sufficient for achieving temperature of 2.0 °C for any scenario, when initial temperature of fish was higher than 11.0 °C.