Pale Translucence Most of the muscle in
most raw fish is white or off-white and
delicately translucent compared to raw beef or
pork, whose cells are surrounded by more
light-scattering connective tissue and fat cells.
Especially fatty portions of fish, such as
salmon and tuna bellies, look distinctly milky
compared to flesh from just a few inches
away. The translucence of fish muscle is
turned into opacity by cooking treatments that
cause the muscle proteins to unfold and bond
to each other into large, light-scattering
masses. Both heat and marination in acid
unfold proteins and turn fish flesh opaque.
Red Tunas The meaty color of certain tunas
is caused by the oxygen-storing pigment
myoglobin (p. 132), which these fish need for
their nonstop, high-velocity life (p. 201). Fish
myoglobin is especially prone to being
oxidized to brownish metmyoglobin,
especially at freezer temperatures down to –