Grades & Classes of Seafood & fish

Objectives To learn the classification methods for fish and seafood To identify specialty fish and seafood products To identify fish and seafood quality

Terminology grading— processors evaluate and divide the fish into processing groups depending on size and body shape stunning— ship processors use electrical shock as a method to paralyze fish beheading— removing the head with a band saw

Terminology evisceration— removing the entrails of a fish by slitting the belly skinning/scaling— removing all skin and scales cutting— fish are sliced into respective portions (i.e., steaks or filets) packaging— fish are packaged, frozen, stored and shipped to distributors

How fish are sold whole or natural state— consumers must remove the head, skin and viscera before cooking; Uncommon drawn— removal of only the viscera dressed or pan-dressed— removal of the viscera, skin, head, tail and fins; most common

Fish Processing trends processing factory ships Using filleting machines and quick-freezing equipment Packing fish on ice when quick-freezing equipment is not available on the ship Processing and packaging fish at dockside processing facilities Practicing fish eviscerating and ice packaging is typical of U.S. fisherman

Fish Processing trends off-shore processing plant fish usually are processed within 24 hours of arrival Avoiding temperature abuse leading to chemical hazards

Fish Processing Steps grading washing stunning beheading gutting scaling skinning cutting/filleting packaging freezing

Classification

Fish Classifications Freshwater versus saltwater Muscle texture versus body shape Cartilaginous versus bony Scales versus skin Migratory versus non-migratory habits

Color Used as an identification method Considered non-reliable because fish change colors from: being hooked being stressed being out of water being exposed to environmental changes spawning (trout and salmon change colors)

Muscle & edibility characteristics Muscling Edibility blood line (i.e., a dark area following the lateral line oiliness flakiness Edibility fat odor color flavor firmness moistness coarseness

Classified by anatomy (i.e., body part location determines fish type) Finfish or shellfish? Classified by anatomy (i.e., body part location determines fish type)

Finfish or Shellfish Finfish Shellfish have a bony and cartilaginous anatomy have a backbone have a head, mid-section and tail Shellfish mollusks and crustaceans are included species do not all have a backbone shellfish have a harder, outside shell or exoskeleton to protect their soft body

Finfish Bony Cartilaginous trout salmon catfish bass tuna blue gill sharks rays skates

Shellfish Mollusks Crustaceans mussel oyster scallop squid octopus clam Crustaceans shrimp lobster crawfish crab

Saltwater Fish Commercial Reef Rock Bottom Surface Warm-water Cold-water Light and heavy tackle Migratory versus non-migratory

Quality?

High-Quality characteristics Clear full and bright eyes Red, slime-free gills Mild, fresh odor Tight, firm skin

Poor-Quality characteristics Cloudy, sunken eyes Light pink, gray or green; slimy eyes Dry dull, colored skin Voids (i.e., hollow areas or defects)

Fillet and Steak quality characteristics Appear to be “fresh cut” Contain no discolorations Is firm in texture Smell with a mild odor graders use smell when inspecting

Shellfish quality characteristics Show leg movement in lobsters and crabs lobsters’ tails should curl under/toward the body when picked up Contain hard, well-shaped and tightly sealed shells for oysters and clams shells not sealed may contain dead shellfish

Fish inspection and Grading Is voluntary Similar to standards set by USDA for agricultural products Is administered by the National Marine Fisheries Services of the Department of Commerce works with other state agencies on food safety and honest representation issues