Shellfish Chapter 20 Pgs.
Ingredient and Materials Learning Objectives:
Identify an assortment of shellfish commonly used in foodservice, to include, crustaceans, mollusks and cephalopods.
Determine quality in crustaceans, mollusks and cephalopods.
Distinguish between varieties of commercially produced shrimp, identify male and female specimens of American Lobster and Blue Crab.
Identify the uses of shellfish in the food service industry.
Research aquaculture to develop an understanding of the importance of this type of renewable food stock.
After studying this chapter, the student should be able to do the
Clean a soft shell crab, debeard a mussel, shuck an oyster and open a clam.
Kill and/or clean a Dungeness crab or a lobster.
Prepare shellfish to industry standards of quality utilizing dry and moist heat methods of cooking: sauté, broil, bake, steam, simmer/boil.
5. Practice knife skills to include dicing, brunoise, julienne, and rough cut.
6. Prepare one secondary sauce to accompany shellfish.
7. Evaluate shellfish dishes for industry standards of quality.
8. Discuss the methods of storage for live, fresh and frozen shell fish.
9. Store shellfish products in safe manner
Bi-valve Cephalopod filter-feeders
Gastropod Uni-valve maximum sustainable yield
Shellfish depuration Roe Hermaphrodite
National Shellfish Sanitation Program Sodium Tri-polyphosphate
Coral Green shrimp Jimmy Crab
P&D Prawn Scampi
She-crab Tomalley Soft Shell
Shellfish include any of many species of aquatic invertebrates with shell carapaces found in saltwater and freshwater regions worldwide, most are edible. Shellfish are categorized into the principle classes of crustaceans and mollusks. Crustaceans are characterized by a hard out shell and jointed appendages; these include crab, lobster and shrimp. Gastropods, another name for a uni-or bi- valve mollusks are characterized by a soft, unsegmented body without internal skeleton, many have hard outer shells;these includes univalves (example, abalone), bivalves (example, clams) and cephalopods ( example, octopus). Shellfish are a popular and abundant food in the U.S. and featured in many international cuisines. They must be handled and prepared carefully to be at their very best.
Quite simply, shellfish are animals contained in a shell. They have no fins, vertebrae or skull. Their meat is tender because the muscles are soft.
Gastropods or mollusks:
Mollusks have a soft, unsegmented body which may be completely or partially enclosed in a shell. Clams, mussels, scallops, and oysters are some examples of
Possess segmented, elongated bodies with crustlike shells. Their eyes are mounted on stalks and their bodies may or may not be symmetrical. Lobsters,
crabs, and shrimp are some representatives of crustaceans.
Cephalopods: No shell, built like a turbine, examples are octopus, calamari, and squid.
Since each shellfish has distinguishing characteristics, a brief description of each follows:
Clams -- Clams abound on the Atlantic and Pacific coasts. Hard, soft, and surf clams are found in the Atlantic. Butter, littleneck, razor and piso clams are
scattered along the floor of the Pacific. Hard-shelled clams are called "quahog" in New England, where the word "clam" refers to the soft-shelled variety. In the middle Atlantic states, "clam" means the hard clam. Clam meat is
orange in color and can be used in any recipe which calls for oysters.
Crabs -- There are three common types of crabs. The blue crab is found along the Atlantic and Gulf coasts. Dungeness crabs inhabit the Pacific. The king crab lives
in the chilly waters off the Alaskan coast. The stone crabs and the tanner crabs are not as well-known, but are becoming increasingly popular. A common misconception concerns the soft-shelled crab. They are not a separate
species. Soft- shelled crabs are blue crabs who have molted and the new shell has not had time to harden.
Lobsters -- Northern lobster is found off the coasts of Maine and Massachusetts, while spiny or rock lobsters pick their way along the Florida and California coasts.
Not only do lobsters vary in locale, but in general appearance as well. Northern lobsters possess pincers while spiny lobsters don't.
Mussels -- Mussels are found in fresh and salt-water, but only salt-water mussels are eaten. A favorite in Europe, mussels do not enjoy the popularity of the other
seafoods in the United States.
Oysters -- There are three types of oysters. The Eastern oysters are found or cultivated from Massachusetts to Texas along the East and Gulf coasts. The Pacific and Western, or Olympia, oysters are found or cultivated along
the West coast from Washington to Mexico.
Periwinkles -- -Periwinkles are small snails found in fresh and salt-water in Europe and off the Eastern coast of North America.
Prawns -- Prawns are found in temperate and tropical waters, and fresh water. They resemble and are often mistaken for large shrimp. Unlike shrimp, however, prawns do not possess a visible vein which requires cleaning.
Scallops -- Scallops differ from other mollusks in that they are active swimmers. By snapping its shell and spurting out a jet of water the scallop can move about.
This novel form of locomotion causes the development of an over-sized muscle called the abductor muscle. This is the only part of the scallop which is eaten by Americans.
Sea and bay scallops are the most common types. Sea scallops are taken from the North and Mid-Atlantic waters.
They are generally larger than bay scallops which are found in the bays from New England to the Gulf of Mexico.
Gaining in popularity in recent years are the calico scallops from Florida and the sea scallops from Alaska.
Scallops may be substituted for shrimp in most recipes.
Shrimp -- There are various species of shrimp. Raw shrimp is distinguished by color. The common or white shrimp is greenish- gray. Brown or Brazilian shrimp is
brownish-red. Pink or coral shrimp is pink or coral. When cooked, however, all shrimp turn pinkish-red in color. Shrimp are caught in the coastal waters of the United States, but the majority come from the Gulf of Mexico.
Like finfish, shellfish are very nutritious. They are particularly rich in the minerals calcium, phosphorous, iron, copper, magnesium, and iodine. Although the amounts vary with the type of shellfish, vitamins A., B, and D are
usually present. Shellfish are also a good source of protein
Unlike finfish, which have varying fat contents, all shellfish are lean and low in salt. This makes mollusks and crustaceans excellent choices for low calorie and low
Why are shellfish more perishable than meats and dairy products?
* Body chemistry is different than land animals, more natural minerals and ammonia and Sulphur due to the water environment-cooler temperature, wet and cold.
* Body processes regulated by enzymes which in shell/fin fish are at a much lower temperature than hot blooded animals
* increase in temperature causes increase in enzymes to function faster-breaks down the cellular structure quicker.
How should they be handled to preserve shelf life?
* keep it cold and use it quicker as fish and shell fish do not get more tender or better with age.
At the Purveyor:
Mollusks undergo a process of depuration with the purveyor. After the shellfish are caught, they are placed in a treated water solution, and allowed to purge sand, excrement and other impurities. This treatment assures a higher standard of sanitation and a longer shelf life in oysters, clams and mussels.
* LOW temp. anything above 40 degrees and rapid break down occurs and deterioration happens.
* Very short shelf life 1-2 days at optimum temperature-use quickly
* Freezing, canning, drying prolongs shelf lfe
* iced and wrapped to keep fresh and moist-KEEP CLEAN
How can we be sure of quality and wholesomeness of the fish and shellfish we buy?
Inspection- Sanitation and Safety versus quality
Different types of inspection- P.U.F.I. mark Indicates Type One inspection.
Type One:Insures wholesomeness, quality product, properly labeled
Type Two: purchase criteria are met.
Type Three: Insures that fishing vessel or plant meets sanitation standards.
Grading- Evaluation of quality, not wholesomeness-they are different!
A,B,C, based on condition, look, smell, feel, odor, flavor, A-fresh,
B, and C, get canned. Example: tuna… this is not mandatory!
The reputation of your purveyor-
Ethical- is it a clean place, good business practices, or are they dishonest,-common practice is using phosphate dips to prolong “perceived” freshness.Adds water weight- cells break down when cooked and there is much water waste and shrinkage, off flavors and textures-rubbery shrimp as an example, and can be a health hazard to some.
Your receiving practices- Promptly check the following:
* Smell-fresh like the sea or slightly like a cucumber
* appearance- moist , clean, shiny, closed shells if mollusks
physical condition-clean, undamaged, tight shells, lively if lobster or crabs, no bruising. No parts missing such as claws, etc.
Your storage practices- low temp in walk ins
* product should be very cold when it arrives, 28 to 32 degrees.
Repack it in self draining ice. Perf pans over ice. Never let product sit in old soggy wet ice or water.
* plan to use it in one to two days max. KEEP IT COLD!
Why is it important not to overcooked shellfish?
Tough and dry if cooked too long or on too high of heat, protein shrinks 140 rule.
Firm and opaque 145 degrees is done for shell fish. Batch cook for sanitary reasons and food quality.
Treat shellfish protein like egg protein-do not boil-simmer, avoid long prolonged high heat, coat with fat or crumbs to preserve moisture when cooking with dry methods.
Exceptions: Abalone, conch and squid-pound out, and sauté on high heat for 30 seconds per side max to avoid toughness.
Moist methods: Milk, stock based, wine, court bouillon
Dry methods: Butter basted, olive oil and garlic, herbs, tomato based, occasionally demi glaze.
Butter based sauces:
Vegetable or tomato based sauces:
Oil based sauces: Pesto