agent (e.g., TMAO). This greening problem can be effectively
prevented by the use of a reducing agent (e.g., sodium hydrosulfite
or another legally permitted additive) (Tomlinson 1966,
Koizumi and Matsura 1967, Grosjean et al. 1969).
Carotenoids
The carotenoids contribute to the attractive yellow, orange,
and red color of several important fish and shellfish products.
The more expensive seafoods such as lobster, shrimp, salmon,
and red snapper have orange-red integument and/or flesh from
carotenoid pigments. For example, the red color of salmon
is directly related to the price of the product. Carotenoids in
seafoods may be easily oxidized by a lipogenase-like enzyme
(Schwimmer 1981).
Melanosis (Melanin Formation)
Melanosis (melanin formation) or “blackspot” in shrimp during
postmortem storage is caused by phenol oxidase and has
economic implications (Simpson et al. 1987). Consumers consider
shrimp with blackspot to be defective. This problem can
be overcome by the use of appropriate reducing or inhibiting
agent(s).
A comprehensive review of the biochemistry of color and
color change in seafood was presented by Haard (1992a). Readers
should refer to this reference for detailed information on this
subject.