Canning and Fish Packaging Technology

Unit 6 - Canning of commercially important fishes and shellfishes

6.2.3.2.Canning of Crab
Canning of crab differs from fish and shrimp in that it is subjected to heat prior to meat separation. Only live crabs are used for canning. They are butchered by removing the carapace or back shell, eviscerated, and allowed to bleed as much as possible. Then they are washed thoroughly in running water to remove even traces of its blood. The claws are separated and washed thoroughly. The washed claws and body are blanched in 2% salt brine for 10 to 15 min, cooled in ice water and the meat is picked using scissors/knife. Picked meat is packed into cans either as single face pack, i.e. body meat is packed into the can and on the top claw meat is arranged or on double face pack i.e. claw meat is arranged on top and bottom end of the can and finally filled with 2% brine containing 0.2% citric acid. The can is then exhausted and heat processed. Crab meat is also canned as a dry pack without any filling medium.

Some problems associated with canned crab meat are,

• Blackening or black discolouration. This problem is minimised by giving a lining of parchment paper to the can.
• Retort burn.
• Blue discolouration. Bleeding the crab and washing thoroughly can minimise this problem. This problem can also be eliminated by the addition of chelating agents such as EDTA or citric acid in the filling brine.