Fish and Shellfish
Ag Processing Technology
Unit 3
Objectives
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Identify three fish and three shellfish used for food
Describe aquaculture and processing
Discuss the composition of fish and shellfish
Indentify three spoilage issues associated with fish
Describe two processes that ensure quality
List four factors that affect the grading of fish
List four fish products and by-products
Describe two methods for preserving fish
Explain the methods of inspection during processing
Introduction
Due to the popularity of fish and shellfish
many are commercially produced
 Processed fish and shellfish are checked
for quality and graded.
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Fish, Shellfish, Salt-and
Freshwater
Fish, Shellfish, Salt and Freshwater
Fish are classifed into varieties
 Flavor depends on the water in which they
are grown
 They are also classified on the basis of
their fat content
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– Lean: less than 2% Fat
– Fat: greater than 5% Fat
Common Species of Edible Fish
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Catfish
Trout
Cod
Halibut
Haddock
Pollock
Salmon
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Tuna
Mackerel
Herring
Shad
Tilapia
Eel
Fishing Vs Culture
Firms that produce and process fish are
located throughout the US
 American consumers used approximately
8% of the total world catch
 This supply is provided by commercial
fishermen, aquaculture producers and
imports
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Aquaculture
Helps meet the demand for fish and
shellfish
 Facilities cultivate approximately 30
different species of fish and shellfish
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Products from Aquaculture
Catfish- farms concentrated in Mississippi, Arkansas,
Alabama, Louisiana
 Rainbow Trout- significant production in Idaho
 Oysters & Clams- Mid-Atlantic coast, Gulf of Mexico,
Washington state
 Shrimp & Prawns- southern United State, Hawaii,
Southeast Asia, South America, Central America
 Salmon-ocean pens in Washington and Maine, hatcheries
for release on the east and west coast
 Other products: baitfish, crayfish, hybrid striped bass,
tilapia, yellow perch, walleye, bass, sturgeon, alligators,
shrimp
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Processing
1,500 plants
 Most are small and family owned
 A few concentrate on a single species—
tuna, salmon, menhaden
 Most process several different species
 Most is processed into seafood
 Some is processed into animal feeds, fish
oils, other products
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Aquaculture Processing
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These steps are used for catfish processing but the steps are similar for
trout and other finfish
Receiving and weighing live fish at the processing plant
2) Holding them alive until needed
3) Stunning
4) Deheading
5) Eviscerating
6) Skinning
7) Chilling
8) Size Grading
9) Freezing or ice packing
10) Packaging
11) Warehousing
12) Icing
13) Shipping the finished product
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Inspection
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Does not fall under the regulations of the USDA
Must contact local county health officials before
processing
Must comply with county health regulations
Must obtain a health permit
Must adhere to standards set forth by the Good
Manufacturing Practice Code of Federal
Regulations Title 21 Part 110
Also subject to announced and unannounced
inspection by the FDA
HACCP
Hazard Analysis and Critical Control Point
 Replaced the reactive system that was
formerly in place
 Regulations for seafood took effect Dec.
18, 1997
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Quality
#1 priority of the aquaculture industry
 To maintain quality and promote consumer
confidence major commercial fish producers
contract voluntarily with the National Marine
Fisheries Service for plant inspection
 Inspectors determine whether the product is
safe, clean, wholesome and properly labeled
 Equipment, facilities, and food handling
personnel must also establish sanitation and
hygienic standards
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Grading
Industry uses to buy and sell
 Consumers use to purchase high quality
products
 US Grade A indicates a product of high
quality
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– The product is of high quality, uniform in size,
practically free of blemish and defect, in
excellent condition and has good flavor and
odor
Earning the Grade A Score
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Each fish is scored for 5 factors
– Appearance: overall appearance, includes consistency
of flesh, odor, eye, gills and skin
– Discoloration- any colors not characteristic to the
species
– Surface defects- the presence of the fins- ragged,
torn, or loose, bruises, damaged muscle
– Cutting and Trimming Defects- body cavity cuts,
improper washing, improper deheading, eviseration
defects
– Improper boning- for fillets only, refers to the
presence of a unspecified bone or piece of bone
Earning the Grade A Score
After inspection the number of defects are
totaled
 Grade A is given when the maximum
number of minor defects is 3 or less and
no major defects are present
 Must also possess good flavor and odor for
the species
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Grade B
5 minor defects and 1 major defect
 Must also possess reasonably good flavor
and odor for the species
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Products
Whole or Round- just as they come out of
the water
 Drawn- only the entrails removed
 Dressed- scaled and eviscerated and head,
tail and fins are removed
Steaks- cross-cut sections of the larger sized
dressed fish
 Fillets- sides of fish cut lengthwise away
from the backbone
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Products
Sticks- uniform pieces of fish cut
lengthwise or crosswise from fillets or
steaks
 Nuggets- fillets only smaller
 Other is manufactured into products such
as breaded, formed and immitation
products. Some is cured and some is
canned.
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Products
Shellfish
marketed in the shell, shucked and
headless
 Shrimp is also sold as peeled, cleaned and
breaded
 Shrimp are designated Jumbo, large,
medium and small based on the number
per pound
 Oysters receive a similar designation
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Fish By-Products
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Fish parts (intestines, heads, gills and less
flavored fish) are not sold for human
consumption
– Ground, dried and converted to fish meal for use as
animal feed or fertilizer
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Fish Protein Concentrate (FPC) or fish flour is
produced from dehydrated and defatted fish
– Used to supplement the breads and cereal products
of people in many parts of the world
Fish By-Products
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Roe
– Mass of eggs and sacs of connective tissue
enclosing the thousdands of eggs
– Some people eat the roe of fish such as the
Shad
– Caviar is sturgeon roe that has been
preserved in brine.
Storing Fish
Must never sit unrefrigerated long
 Seafood with bruises or punctures spoils
more easily
 Fish and shell fish should be cooked within
2 days of purchase or frozen
 Frozen fish should be used within 2
months
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Storing Shellfish
Oysters, clams and mussels are stored in the
refrigerator at about 35 degrees F, they should
be kept damp but not placed on ice or in
freshwater or an airtight container
 Live lobster and crab are stored in the
refrigerator in moist packaging but not airtight
containers, water or salted water
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– Lobsters should generally remain alive for 24 hours
New Products
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Surimi: flavorless, odorless high protein
fish product
– Made by mincing fish flesh left over from
filleting and underutilized fish species
– Minced flesh is washed to remove solubles
(including color and flavors)
– Used to make imitation crab and lobster meat
Summary
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Fish include fresh and saltwater species
Shellfish include mollusks and crustaceans like
clam, oyster and lobster
Provided by commercial fishing and aquaculture
producers
Provide high quality protein, B vitamins, calcium,
phosphorus, iodine, potassium
Fish require strict processing and preservation
procedures due to their easy spoilage