Friday, June 6, 2008

Cooking fish

Fish and shellfish contain high-quality protein and other essential nutrients, are low in saturated fat, and contain omega-3 fatty acids. A well-balanced diet that includes a variety of fish and shellfish can contribute to heart health and children's proper growth and development. In addition, fish contains important B vitamins that help with cognitive ability and memory. Women and young children in particular should include fish or shellfish in their diets due to the many nutritional benefits.

Unfortunately, today, the world’s oceans contain enormous quantities of methyl mercury as well as other contaminants. In all industrialized countries, industry releases several million pounds of mercury and mercury compounds to the atmosphere each year. This continual release of mercury into the atmosphere (mostly from coal-burning electrical generating plants) creates an abundance of mercury vapor that hangs in the sky. When mercury is removed from the atmosphere by precipitation, it ends up in lakes, streams, rivers and oceans. The mercury then bonds with algae which is then eaten by small fish, which are eaten by larger fish.

Nearly all fish contain trace amounts of methyl mercury some more than others, which are not harmful to humans. However, long-lived, larger fish that feed on other fish accumulate the highest levels of methyl mercury and pose the greatest risk to people who eat them regularly. It is another sad sign of our times that the fish we eat have become our primary source of environmental exposure to mercury.

In addition, mercury binds tightly to proteins in fish tissue, including muscle. This toxic material builds up over time in a process called bioaccumulation and, contrary to popular belief, cooking does not do nearly enough to reduce the mercury content. Fish also contain high levels of selenium, a mineral that specifically binds and neutralizes mercury—a little-known fact of marine biology. Some think that the selenium could help to offset the presence of mercury, but there is insufficient data to support this.

It is important that pregnant women, nursing mothers and young children should avoid the following large fishes that can contain high levels of mercury that can harm the nervous system:
Shark
Swordfish
King mackerel
Tilefish

While I cannot tell you to avoid fish altogether, I strongly encourage you to be careful about which fish you eat. The risks from mercury in fish and shellfish depend on the amount of fish and shellfish eaten and the levels of mercury in the fish and shellfish. Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.

Buying, Storing and Handling fish

Remember to buy seafood last and never place other shopping items on top of the fish.

Fresh whole fish should have:
• A shiny surface with tightly adhering scales.
• Gills that is deep red or pink, free of slime, mucus and off-odor.
• Clean shiny belly cavity with no cuts or protruding bones.
• Clear shiny eyes

Fish steaks, fillets and cuts should have:
• A translucent look.
• Flesh should be firm and not separating.
• No discoloration.
• Packaging that keeps them from being bent in an unnatural position.

Preparation

• Keep raw and cooked seafood separate to prevent bacterial cross-contamination.
• After handling raw seafood thoroughly wash knives, cutting surfaces, sponges and your hands with hot soapy water.
• Always marinate seafood in the refrigerator.
• Discard marinade; it contains raw juices which may harbor bacteria.
• If the marinade is needed for basting keep aside a portion before adding raw seafood.

Cooking tips

• Fish cooks quickly. Do not overcook.
• Fish is cooked when the flesh becomes opaque and flakes easily when tested with a fork.
• The general cooking rule is 10 minutes per inch of thickness, at 400-450 degrees F.
• If cooking fish in parchment, foil or a sauce, add 5 minutes to the total cooking time.
• Fillets less than 1/2 inch thick do not need to be turned during cooking.
• Poaching, steaming, baking, broiling, sautéing, microwaving are excellent low-fat cooking methods, if you do not add high fat ingredients.
• Broil, bake, steam or microwave, then cube and add to pasta or salad greens for a delicious salad.
• Oil the grill to prevent fish from sticking.
• Add a piece of ginger to remove the fishy smell, when cooking fish soups or porridge.

No comments: