Selecting Safe Seafood: Q & A
Interview with Kantha Shelke, PhD, Institute of Food Technologists (IFT) Member and principal at Corvus Blue LLC, a Chicago-based food science and research firm
Q: What should you look for when shopping for fresh seafood?
A: When shopping for fresh seafood, choose seafood with a faint sea odor. Fresh seafood should not smell "fishy." Freshly cut fish, peeled crustaceans (prawns, shrimp, lobster, soft shell crabs, and rock shrimp) and shucked mollusks (clams, scallops, oysters, and mussels) should be moist, not slimy or dried around the edges.
Fresh, high-quality fish should have clear, well-rounded eyes as opposed to clouded, dry and sunken eyes, which are characteristics of older fish. The gills of a fresh fish are bright red, not darkened or slimy. The feel of the fish should be moist and springy, not mushy.
Fresh crustaceans in the shell—prawns, shrimp, lobster, soft shell crabs, and rock shrimp—should have a uniformly light colored tail without any discoloration, sliminess or smelliness.
Mollusks purchased in the shell should be alive and hold tightly to their shells when handled and must be accompanied with either a "last sale date" or "date shucked." Fresh oysters should have a natural creamy color within a clear liquid.
Q: How long does fresh seafood stay fresh? What is the best way to store it?
A: Ideally, seafood should be purchased the day it is going to be used. If that is not possible, it must be appropriately stored in the refrigerator or freezer until it is prepared and cooked.
Fresh fish, shrimp, scallops, freshwater prawns, and lobster tails can be stored in zip-top storage bags or plastic storage containers and kept on ice in the refrigerator (32-34 degrees Farhenheit). When stored this way, fresh scallops and crustacean tails can last 3-4 days and fresh fish will keep 5-7 days.
Scallops, crustacean tails, and fish can be frozen in water and stored in a freezer at 0 degrees Fahrenheit or lower for 4-6 months. To thaw, place overnight in the refrigerator or under cold, running tap water immediately before use.
Live, hardshell mollusks can remain alive for 7-10 days stored un-iced in the refrigerator at 34-38 degrees Fahrenheit.
Freshly shucked mollusks can last for a week to 10 days when packed in ice and stored in the refrigerator.
Fresh softshell crabs can be stored up to 2 days if wrapped in plastic and packed in ice in the refrigerator. They can be stored for up to 6 months when wrapped in several layers of plastic and stored in a freezer at 0 degrees Fahrenheit. Be sure to thaw overnight in the refrigerator only.
Q: Are there any tips for buying frozen seafood? Is some seafood better to buy frozen rather than fresh?
A: Advances in freezing technologies have made the quality of frozen fish to be as superior to fish sold fresh. Today, fish is often frozen on the boat just minutes after being caught. Specialized flash-freezing units that maintain a temperature far below the typical home freezer make it possible to maintain a "freshly caught" quality even after shipping it miles away. Often, "fresh" fish sold in grocery stores are in fact previously frozen fish. Not all fish sold has 'previously frozen' on the card identifying the fish.
If you live within 100 miles of a coast or Great Lakes, then buy fresh fish that is local and in season. If you are outside this area, you are better off buying frozen fish.
Q: Following the Gulf oil spill, is fish from Louisiana safe for consumption?
A: It is important to remember that the entire Gulf was not contaminated by the oil spill. Most of the leak was around the Deepwater Horizon rig, which was immediately closed to fishing by the FDA and other federal and state agencies. Testing of the seafood on a regular basis for dangerous compounds occurred so that it could be determined which areas were safe and which were not.
Q: We know that fruits and vegetables are seasonal. Can this same concept be applied to the seafood industry? Are there better months to buy certain fish to ensure their freshness or taste?
A: Yes. The old adage about 'buying and consuming oysters only in months that contain the letter R' may also be applied to seafood consumption. Avoid eating fresh wild-caught fish harvested during their spawning time (April-August). Your grocer can tell you about 'out of season' dates for different types of fish.