salmon aroma may be due in part to the stores
of pink astaxanthin pigment, which the fish
accumulate from ocean crustaceans (p. 194),
and which when heated gives rise to volatile
molecules found in and reminiscent of fruits
and flowers.
Trouts and Chars These mainly freshwater
offshoots of the salmons are excellent sport
fish and so have been transplanted from their
home waters to lakes and streams all over the
world. Their flesh lacks the salmon coloration
because their diet doesn’t include the
pigmented ocean crustaceans. Today, the trout
found in U.S. markets and restaurants are
almost all farmed rainbows. On a diet of fish
and animal meal and vitamins, rainbow trout
take just a year from egg to mild, single-
portion (0.5–1 lb/225–450 gm) fish. The
Norwegians and Japanese raise exactly the
same species in saltwater to produce a farmed
version of the steelhead trout, which can reach