The main issue associated with chilling post-mortem prior to gutting is ensuring chill rates are optimal for shelf life and quality and the efficiency of the gutting process with the aim to pack gutted fish as close to 0 C as possible. Many existing processes actually deliver fish too cold to gutting which causes a type of "false rigor" leading to gutting machine miscuts, gut and kidney residue, and increased fish bypassing to manual lines.
Post-gut chilling is not often used but is very efficient and the few process lines that have adopted this approach have seen large benefits. Simply add a small screwchiller for example after the gutting line and get a rapid drop in temperarure due to the body cavity being open. This also allows a buffer in production for any issues that occur downstream on the beltgrader or upstream at gutting and delivery. It also ensures fish that are packed gutted will be packed close to 0C which means the ice is only there to maintain quality by keeping conditions moist and humid and a small allowance for breaks in the chill chain NOT TO CHILL FISH FROM 3-4C DOWN TO 0C. This means the customer gets fish from a box full of ice and not a smelly bloody ice slurry.
This simple step makes your fish stand out from the great majority - especially during the warmer months!
So, consider gutting fish warm - many standards specify 4 C maximum delivery to gutting but this needs review where fish are pre-rigor, and post-gut chilling is used to rapidly drop temperature before packing.
