Seafood ChoiCeS

Seafood Choices: Balancing Benefits and Risks
http://www.nap.edu/catalog/11762.html
CONSUMPTION PATTERNS AND COMPOSITION OF SEAFOOD
BOX 2-1
Tuna: White vs. Light
Tuna is the most popular fish used for canning and is the second most consumed
type of seafood in the United States. Japan and the United States
consume 36 and 31 percent, respectively, of the global tuna catch.
Tuna is a predatory fish that, if consumed in large quantities, may contain
levels of methylmercury that exceed recommended safe levels. Although
many different tuna species are fished, the most popular commercial varieties
are described below.
White Tuna
Albacore—high in fat and rich in EPA/DHA; it has the whitest flesh and
is typically referred to as white tuna; it is eaten both canned and fresh.
Albacore generally contains more methylmercury than other types of tuna
and may also contain more lipophilic compounds.
Northern Bluefin—high in fat and EPA/DHA; it is a slow-growing and thus
rarer species than albacore and has a very high-quality meat; its major
market is Japan, where it is used for sashimi.
Southern Bluefin—stocks are in decline and thus it is harder to obtain than
other tunas. It is the most expensive fresh tuna.
Light Tuna
Skipjack—leaner than albacore tuna; it is the most commonly used tuna
for canning.
Yellowfin—larger and leaner than albacore; it has pale pink flesh and is
the second most popular species of tuna used in canning.
Bigeye—similar to yellowfin; it has a milder flavor than skipjack or yellowfin
and is frequently used in canning.
Most canned tuna sold in the United States is available as “solid,” also
called “fancy” (a solid piece of loin, cut to fit the can); or “chunk” (a mixture
of cut pieces). Canned tuna comes packed in either oil or water and is
labeled either “white” or “light.” Chunk light tuna packed in water is the
most popular form of canned tuna sold in the United States. The source
for most of this tuna is skipjack, although individual cans may contain more
than one species of tuna. Albacore or “white” tuna is almost always packed
in water in solid form.
NOTES: A standard of identity is used to define the species of fish that may be
canned under the name “tuna” (21 CFR 161.190[a]). There is also a standard for
fill-of-container of canned tuna (21 CFR 161.190[c]). These standards provide for
various styles of pack, including solid pack, chunk or chunk style, flakes, and grated
tuna. Provision is also made for type of packing media (water or oil), certain specified
seasonings and flavorings, color designations, and methods for determining
fill-of-containers (Source: http://www.cfsan.fda.gov/~dms/qa-ind4g.html).
SOURCE: Derived from US Tuna Foundation (http://www.tunafacts.org/abouttuna/
index.html).
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