Fish and Shellfish

Fish and Shellfish Ag Processing Technology Unit 3

Objectives • 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.

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 • Lean: less than 2% Fat • Fat: greater than 5% Fat

Catfish Trout Cod Halibut Haddock Pollock Salmon Tuna Mackerel Herring Shad Tilapia Eel Common Species of Edible Fish

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

Aquaculture • Helps meet the demand for fish and shellfish • Facilities cultivate approximately 30 different species of fish and shellfish

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

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

Aquaculture Processing • 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 • Holding them alive until needed • Stunning • Deheading • Eviscerating • Skinning • Chilling • Size Grading • Freezing or ice packing • Packaging • Warehousing • Icing • Shipping the finished product

Inspection • 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

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

Grading • Industry uses to buy and sell • Consumers use to purchase high quality products • US Grade A indicates a product of high quality • 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 • 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 A

Grade B • 5 minor defects and 1 major defect • Must also possess reasonably good flavor and odor for the species B

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

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.

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

Fish By-Products • 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 • 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 • 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

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 • Lobsters should generally remain alive for 24 hours

New Products • 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 • 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

Fish and Shellfish