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Fish for Supper

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OSU research helps keep seafood safe and sustainable.

Oregon has the world’s finest seafood. And Oregon State University has state-of-the-science research that helps keep seafood fresh, safe, and abundant.

Take oysters, for example. For many people, slurping down a raw oyster straight from the shell is a gastronomic delight. For a few people, that delight can be followed by a belly punch. There’s a nasty group of organisms called Vibrio that lurks in raw shellfish and can cause gastroenteritis. Researchers at OSU have found ways to kill Vibrio by subjecting oysters in the shell to very high pressure for about two minutes. The result is safe-to-eat, easy-to-shuck raw oysters.

Seafood has a notoriously short shelf life. Fish, like visitors, stink after three days. OSU food technologists have developed a thin protective film that can be used to coat fish fillets to keep them fresh much longer. Yanyun Zhao and research associate Jingyun Duan developed the edible coating from a mixture of fish oil and chitosan made from crustacean shells. The coating not only increases the shelf life of fresh fillets, it also adds nutritious omega-3 fatty acids to less oily fish.

Some seafood gets a bad rap for containing mercury. Because fish absorb mercury from their environment, fish that live in contaminated water or those that are older, larger, and higher on the food chain tend to accumulate more methylmercury in their tissues. Locally caught Oregon salmon, shrimp, flounder, and oysters are very low in mercury. But until recently, mercury content in tuna was averaged for all species, with no distinction made between small, young Oregon albacore and much larger, older tuna from the south Pacific.

OSU researchers compared mercury levels of commercial species of tuna and found that albacore caught off the Pacific Northwest coast have substantially lower mercury levels than the rest, well below FDA limits. And these small, cold-water-loving tuna are notably higher in omega-3 fatty acids.

What about sustainability? Recent reports of declining ocean stocks and closures of salmon fishing seasons remind us that seafood is not limitless. Fisheries managers try to encourage use of abundant fish populations and reduce harvest of weak stocks. But a strange new fish on the market might not be immediately embraced by consumers.

surimi photo by Lynn Ketchum
With the help of OSU research, surimi has become a major international commodity. Photo by Lynn Ketchum.

Jae Park has helped pioneer ways to process low-value fish into surimi, a seafood product that can be made to imitate popular seafood like crab and scallops. His research turned fish that nobody wanted into a high-value product that revitalized fisheries in Oregon and beyond. Since 1993, Park and colleagues have hosted the Surimi School at the OSU Seafood Lab in Astoria and in locations around the world to demonstrate new surimi processing techniques to food scientists and manufacturers. Since then, surimi has become a major international commodity with an annual value of $2.2 billion.

Okay, so Oregon seafood is safe and sustainable. But what if it glows in the dark? As weird as it seems, glowing seafood does not present a food safety problem, nor does it reflect mishandling during processing, according to Kaety Hildenbrand, an OSU Sea Grant Extension specialist. “It’s caused by a harmless marine bacteria and it’s surprisingly common,” she says, especially in seafoods that have been processed with added salt.

Something to look forward to at your next candlelight dinner.

Published in: Food Systems