page 185: swordfish (and tuna) as a long-lived predator at the top of the food chain may accumulate significant amounts of toxins, especially mercury.
page 202: Atlantic stock of swordfish is thought to be down to less than a tenth its original size and in need of protection.
page 209: in swordfish, enzymes and some proteins in muscle cells are not locked in the contracting fibrils and furthermore coagulate at higher temperatures than myosin, so when myosin coagulates and squeezes out cell fluids including these proteins and enzymes, at 55°C and above these proteins coagulate in the spaces between the cells and glue the cells together, thus making the meat more chewy.
So for swordfish and tuna it might be wise to restrict target temperature to 50°C or below, and a 5cm steak may take 2½ - 3 hrs.
BTW here's a trick how to transfer fish into the skillet for searing without falling apart: lay the bag flat on a cutting board, with a sharp knife cut the bag open all around the fish, remove the top layer and the sideward strips of the bag and slide the fish into the skillet.
Edited by PedroG, 27 September 2010 - 01:13 AM.