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Taking the Mystery out of Meat


A fast, easy way to check meat products for safety is now at hand.

By Parker Neils

Photo by Ray Stanyard

Order red snapper at a restaurant, and find there's rockfish under the sauce. That's cheating.

Buy ground beef that in truth is part horse meat. That's cheating and unsavory.

Bite into a rib-eye tainted with mad cow disease. That can kill you.

It's the bane of consumers everywhere—the risks we take when we buy meat products. Each year in the U.S. alone, more than 5,000 people die from eating spoiled or tainted meat. Untold others get sickened by food poisoning.

About 15 years ago, the mad cow scare that originated in Great Britain triggered draconian government measures—such as the wholesale slaughter of herds even suspected of being infected—that nonetheless salvaged the world's beef industry.

Today, mad cow disease is substantially contained, thanks to tightened government regulations. This includes a ban on using certain kinds of animal protein as an additive in feed for such livestock as cattle, sheep and goats. The ban was imposed after scientists discovered that the disease—which often is difficult to detect and verify in living animals—can easily be passed from tainted meat—and-bone meal—a main ingredient of high-protein livestock feeds—into healthy herds. In fact, this recycling of the disease is identified as the primary reason why the deadly malady continues to be a threat to consumers today.

Enforcing the ban continues to be a problem, however, and it's aggravated by the fact that until recently, government meat inspectors had no reliable method of testing feed for the presence of banned protein. Typically, tests for finding animal protein in meal or feed are based on DNA analysis. But DNA degrades under high temperature, and high heat is necessary for the rendering process used to make protein meal.

“The tests were very time-consuming and producing many false positives and negatives in a highly complex sample such as meat-bone-meal,” says Peggy Hsieh (pronounced shay), a food chemist within FSU's College of Human Sciences. “I foresaw that with the law must come a good test to enforce it.”

As it turns out, as a research scientist working at Auburn University in the 1990s, Hsieh realized she had come up with just such a test. Now in her first year on the FSU faculty, Hsieh is watching her research help protect consumers around the world. Today, no less than a dozen countries are using her technology that has applications well beyond fighting mad cow disease.

Hsieh's specialty is identifying the species of any animal that gets either used as food for other animals or served straight up on a plate. She is the first scientist to devise a fast, reliable method to identify meat species in either raw or cooked food. In other words, she can tell fast-food lovers what exactly is in those “nuggets” (if they're ever inclined to know.)

“I have used the tests for years, but (until recently) no one wanted to develop them commercially,” she said.

Priorities tend to change when life—and a whole McIndustry—is at stake. Recently, two U.S. companies—ELISA Technologies, Inc. of Gainesville, Florida, and Neogen Corporation of Lansing, Michigan—began marketing testing kits, based on Hsieh's now-patented work (licensed by Auburn University) to test animal feed, meat-and-bone meal, and some food. Developed for government auditing, company quality control, feed lots, and research, the two commercial kit types are complementary. Neogen produces a paper-strip test for field use; ELISA Technologies a 96-sample kit for more elaborate laboratory assays.

The key to Hsieh's highly accurate test is her discovery of a protein in muscle tissue that isn't destroyed by cooking. Such a thermostable marker protein makes all the difference in testing the severely cooked products of rendering.

Next was another giant step—developing and patenting particular antibodies that react against the marker protein. These antibody molecules can quickly detect and differentiate between the muscle tissues of ruminants (e.g. cows, goats, sheep)—most important for combating mad cow disease— mammalian muscle, or animal muscle in general.

Aside from their accuracy, Hsieh's test kits have the advantage of being simple, fast and easy to use. For the Neogen field test, anyone can do it, she said. In a container, simply mix a feed sample with a solvent, dip in the prepared test strip, and read the result. An unmistakable black line on the strip means the sample is adulterated. The ELISA Technologies lab kit is similarly streamlined: 96 wells on a single plate pre-coated with antibody. A field test takes only15 minutes; the large lab assay only two hours.

Something Fishy

Now returned to her alma mater (Ph.D., 1987), Hsieh is a petite woman whose stature seems to grow when she talks excitedly about her research. She recalled how she started on the road to becoming a specialist in taking the mystery out of meat. After her doctorate in Tallahassee, she went to work as a food chemist for the Florida Department of Agriculture.

“My first job was to ensure that ground beef really was 100 percent beef. There were no stringent monitoring program to enforce the meat-labeling regulations then,” she said. “I found that 20 percent of 1,000 beef samples contained something else-sheep, pork, bone, chicken gizzard.”

Adulteration of meatstuffs is commonplace in many developing countries, but the findings shocked Hsieh, who thought U.S. standards kept a lid on such practice.

“I didn't believe it could happen here. From that time (forward) I wanted to develop a rapid method for consumer protection and to discourage illegal practices.”

Eventually, encouraged by her professors at FSU who saw in her a rare talent for research, Hsieh returned to academia. At Auburn she rose to a full professorship on the strength of two patents (with five more filed or pending) and became an internationally known researcher on food quality and safety.

Species adulteration or substitution can have significant consequences beyond concern over food-borne pathogens, Hsieh says.

People who suffer from certain food allergies are particularly at risk from eating things they aren't aware of. Then there are religious dietary taboos to consider, not to mention the waste of money on cheap products sold as expensive items.

She's not a crusader, per se, but her expertise has often cast her into the role of a consumer-rights advocate. Hsieh has been an expert witness in lawsuits against dissembling companies and once published results about adulterated sausage sold in Alabama when state officials asked her not to.

Seafood lovers (although not necessary seafood marketers) might well regard her as a hero. Patrons falling for a $34 red snapper entrée at a cozy café might suspect they're paying too much, but many don't have a clue they're often victims of outright fraud.

Unfortunately, red snapper is popular, limited in supply, and high in price, which makes it a perfect menu item for false advertising. In 1995, American Journal television magazine suspected that restaurant patrons in major cities were ordering prized red snapper—and not getting it. The program's producers had read Hsieh's exposé of species-substitution for fresh and frozen red snapper in Florida's retail markets (she found that 70 percent were mislabeled) and believed her lab might be capable of analyzing cooked fish—an assay previously difficult, time—consuming, and impractical.

They were right on all counts. Hsieh found that in four major cities—New York, Boston, Philadelphia, and Washington, D.C.—almost half of all red snapper entrées were imposters. American Journal aired the program. “Managers were fired,” Hsieh says seriously and without relish.

While uncovering the seafood fraud (under FDA regulations) was important, Hsieh's improved technology made bigger news in scientific circles. For identifying fish, scientists traditionally depend on a method called isoelectric focusing. An electric field creates distinctive protein band patterns for each fish. The method is accurate and widely used for raw fish, but cooked fish largely stymied researchers.

Just as in any animal, cooking changes fish proteins and decreases their solubility, making extraction of enough soluble protein numbingly laborious—not to mention that the chef's sauces, spices, and coatings can make such testing unreliable. Once again, success in finding thermostable marker proteins in fish was the critical element to Hsieh's breakthrough.

The fish-identifying technique she came up with includes a simple, fast-rinsing way to clean and desalt fish cooked with any ingredients. It's practically foolproof, too, able to identify fish no matter how they're cooked, whether microwaved, baked, steamed, broiled or fried.

If standardized for wider use, these fish tests could help restaurant inspectors take more fishy fish out of kitchens and “Today's Fake Specials” off blackboards.

From Shop to Kitchen

Hsieh's extraordinary drive as a food scientist continues to produce other technologies geared to making what we eat safer and more useful.

One of her newest patent applications is for a quick and clever way to solve one of life's everyday, domestic mysteries: What stuff in the refrigerator has gone bad?

Worried that perfectly fine-looking, refrigerated food may be spoiled and dangerous, every day Americans toss out expensive food without really knowing, figuring it's better to be safe than sorry.

A device Hsieh has invented may turn out to be the first inexpensive and practical way to solve this problem. The device, small enough to fit into a shirt pocket, sniffs the level of carbon dioxide in leftovers and gives an instant analysis of their palatability. The gas is a telltale byproduct of bacterial growth—too much and it's time to toss that lasagna.

Hsieh says the device, which she calls a microrespirometer, works for liquids or solids and is easily portable.

Perhaps one day, Hsieh's little “Don't-Eat-It! Meter” may be a must-have fixture in every kitchen. As a scientist with a public service bent, she wouldn't mind seeing that, but the search for new and better ways to make mealtime easier and safer will always be her number-one mission, she said.

“If the products of my research serve scientists and people, that's wonderful,” Hsieh professes. “But I love what I do. The quests excite me. I'm incredibly fortunate to have this life.”



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