Somebody had to invent the instant potato flake. And somebody has to study how to detect drug residues in swine feed, what will make consumers like restructured beef and if cows could someday produce skim milk. Those somebodies are scientists at the U.S. Department of Agriculture's Eastern Regional Research Center, and their missions are to find the methods.

The ERRC is not a research farm like Beltsville's Agricultural Research Station, with sprawling pastures and barns. Set in a northwest suburb of Philadelphia, the 1940s building resembles an aging red brick high school.

But inside, among the dozens of labs populated by glass metropolises of beakers and vials, is a small-capacity potato processing plant that looks like a giant Leggo set, a "cheese machine" that is used to experiment with government surplus cheese, an explosion puffing gun that literally explodes the moisture out of fruits and vegetables and a food irradiation facility that is a leading source of information for government decision makers.

This is also where research scientists -- whose offices are decorated with posters and memorabilia of their favorite agricultural commodities -- impart all kinds of tidbits of information useful for cocktail party chatter. For example, a special strain of potato, called the Norchip, was developed expressly to make potato chips.

The ERRC's work is not the stuff of flashy product development (although that may come later if a food company finds an application) or monumental discoveries that land Nobel prizes (although the center did receive the 1959 Institute of Food Technologists' first industrial achievement award for its invention of the instant potato flake).

Instead, the facility concentrates on food safety, post-harvest treatments, storage and handling, food irradiation -- and inedible agricultural subjects, too, such as better ways to process hides and leather.

Another major component of the ERRC's work is to make better use of government agricultural commodities. Some of the results: converting edible beef tallow into a cocoa butter twin (the resulting candy bars are displayed in the center's lobby, as well as in Director John Cherry's office) and turning the whey from cheese-making into lactulose, a commercial sugar that is currently used for medical treatment, but which could also be developed into a noncaloric sweetener for foods.

Yet for all its research, in many ways, the center typifies the schizophrenia of the USDA. As an arm of a government agency, presumably assigned as watchdogs of industry, the Eastern Regional Research Center spends most of its resources helping the same industries the USDA is supposed to regulate. And although some of the projects are meant to benefit both industry and consumers, scientists at ERRC receive awards from industry, requests from industry and feedback from industry.

The center's "number one effort is to learn about industry problems," says Cherry, although he added that the center has a "strong program" that supports the "action agencies" such as the USDA's Food Safety and Inspection Service, or the Food and Drug Administration.

But Cherry says the research role of ERRC benefits the economy of the whole country, not just industry. "Our research is available in published journals," he said, "and available to whoever needs it," such as foreign governments and universities.

And the center does not get involved in proprietary research for industry, but sticks to problems national in scope, Cherry added. As for the projects that are more regulatory in nature, he said that the center's relationship with industry is "not a question of one against the other." The center maintains a "continual dialogue" with industry, Cherry said. "They the industry know they have to come to grips" with certain concerns and the two try to work on them jointly, he said. So here are some of the questions the center is tackling now in its capacity as problem-solver.

Question: How can restructured beef gain better consumer acceptance?

The request for an answer to this question comes from the National Cattlemen's Association, according to John Woychik, chief of the facility's food science lab. The meat industry wants more people to buy restructured beef.

In many ways, restructured beef is the bovine equivalent of surimi, those extruded strips of underutilized fish species spiked with crab extract that are meant to simulate crab meat. Like surimi's effort to provide a luxury look-alike at a lower cost than the real thing, restructed beef is made by processing less desirable cuts of beef with salt and spices and forming it into up-scale shapes, like steaks and roasts.

Problem is, lesser cuts of meat also contain a lot of gristle or connective tissue that renders the final restructured beef tough. (McDonald's' restructured product, the McRib, which failed in its test market stage, is an ideal example of how this plastic surgery doesn't cure all evils.)

Enter the USDA research team, which hopes to find enzymes that will tenderize the gristle without affecting the muscle (tenderized muscles lead to mushy meat). The lab will also try to determine the best way to get the enzyme into the meat, whether it be on its surface, through a needle or during the "tumbling phase" of the restructuring process.

Question: Can the sodium content of processed meats, such as hot dogs and corned beef, be reduced without sacrificing food safety? And what about lowering the sodium in baked goods?

Yes, is the answer to this timely question, says ERRC food scientist Richard Whiting. In fact, Whiting concluded from his recently completed study that a reduction of 20 to 25 percent of sodium will not change the microbiology of the product -- or in other words, your chances of getting food poisoning from a hot dog with 20 percent less sodium are unchanged. In addition, Whiting found that proper refrigeration is more important than the sodium level in retarding the growth of microorganisms.

Although not typical of the type of research the ERRC normally performs, according to Whiting (it's more the type that industry usually does, he said), the project grew out of a concern of the USDA's Food Safety and Inspection Service. The agency wanted to make sure that low-sodium meat products beginning to enter the market were also safe from bacterial growth.

Whiting's protege', Eugene Guy, experimented with reducing the amount of sodium in bread. Guy found that cutting the sodium by as much as half had no loss in bread quality or leavening action.

Whiting's and Guy's findings bring up another question: Why was all the sodium added to begin with?

Whiting suggests that it was initially needed as a preservative in sausage products when refrigeration wasn't prevalent, but in later years remained at relatively the same levels because people just got used to the taste. It has only been recently, since the connection between sodium and high blood pressure has come to the forefront, that people began examining the ingredient's food culprits. But until now, "nobody thought it was a problem, so why take it out?" Whiting said.

Despite his findings, Whiting says some meat packers are still not entirely convinced that they can reduce the sodium in their products by 20 percent. They worry about shelf life, he says. And although he is confident of the results of his study, Whiting added that he doesn't own "100 million pounds of hotdogs" either.

Question: How can computers be used to help food companies ape production lines?

Take a french fry company that processes potatoes all year round, explains scientist Mike Kozempel. Depending on where the potatoes come from and what time of the year it is, the vegetable will differ in sugar, starch, water and solid content. The potatoes from Florida in June will be different than the ones from Pennsylvania in August or the ones from Maine in October.

So let's say the french fry manufacturer wants to extract more sugar from the potatoes from a particular part of the country at a particular time of the year, because he knows that french fries made from sugary potatoes will brown too readily, and he knows that consumers like light-colored french fries.

Kozempel's computer program, "a miniature of the plant," he says, will be able to tell the processor how and how much to change production procedures to create that french fry with the optimal sugar content. Kozempel hopes to extrapolate this procedure so that computers could be used to alter any food operation.

Question: What is an inexpensive way pork producers could use to detect drug residues in swine feed?

Piece together Daniel Schwartz's environment -- tiny glass vials, test tubes and beakers crowded Manhattan-style on a jet-black lab counter, combined with opened bags of swine and chicken feed, and his expertise begins to take shape: detecting drug residues in animal feed.

Most recently, Schwartz developed a test to detect illegal use of chloramphenicol (CAP), a restricted antibiotic in meat animals and dairy cows, and a few years ago, he came up with a simple, inexpensive way for pork producers to detect sulpha drugs in swine feed. (Swine must be weaned from antibiotics in their feed for a week before they are slaughtered.) But what can happen, says Schwartz, is that the feed spiked with antiobiotics is cross contaminated with the pure feed via the animals' troughs.

Schwartz's drug detection kit, which he says should cost only about 25 cents to manufacture, consists of two plastic tubes arranged piggyback style. The feed sample is percolated from the upper tube through a resin, changing the sample to a color anywhere from pink to lavender, depending on the amount of residue in the feed. The producer then compares the color to a master kit, which contains little vials filled with different colored liquids, each simulating a solution with progressive amounts of residue.

Schwartz says that in the early 1980s, he took his drug-detector kit to farmers in Indiana and presented his paper to scientists, but has gotten little response from it. He says that the government is "pretty lax" about detecting and punishing producers for illegal drug residues. The producers realize this, says Schwartz, and so they aren't concerned about finding methods to detect them.

But Schwartz thinks that the problem could even be controlled more easily by holding the animals in the slaughterhouse, instead of at the feed lot, for the week before they are killed. Schwartz, however, says he is doubtful that the slaughterhouses would want to foot the bill.

Question: How can food irradiation be used for commercial products?

In a separate facility apart from the ERRC's main building is the food irradiation lab. In keeping with federal regulations concerning such operations, security is tight. There are several locks to open and electronic cards that must be used to enter the small building, and visitors must sign in and out, verifying via a radiation meter that they have not been exposed to any radiation.

The food irradiator itself is a large, bright red structure that nearly reaches the ceiling. It is surrounded by eight inches of lead and operated by a series of buttons and levers on one side. The food is placed in a one-gallon stainless steel can and lowered into the irradiation chamber where gamma rays (x-rays and electrons are used in other facilities) are then passed through it, killing insects, molds or microorganisms that can lead to spoilage and disease.

According to Donald Thayer, chief of the food safety laboratory, in commercial operations, rather than the food being lowered to the radiation source, the radiation sources are brought to the food. In addition, the radiation is contained in an entire room instead of in a single chamber.

The staff of this facility supervised the completion of the findings of Raltech Scientific Services, the controversial study that temporarily postponed the FDA's approval of pork irradiation. (An enormous bookcase in food safety chief Don Thayer's office is taken up with notebook after notebook of the study's findings and conclusions.)

Aside from the Raltech project, however, the center is coordinating numerous other investigations into applications of irradiation. Among them: the efficacy of gamma or electron irradiation as a substitute or partial substitute for nitrite in bacon, what happens to foods containing polyunsaturated fats when they are irradiated and the reasons why fruits soften after certain dosages of irradiation.

Question: How can the shelf life and perishability of seasonal fruits and vegetables be extended with less cost than freeze drying?

By explosion puffing. The process, which dries foods, allows them to be quickly rehydrated when cooked. It involves no freezing (no refrigeration needed for shipping, either) and according to the USDA, requires less energy than conventional food drying systems. Cherry's office houses a virtual supermarket of explosion-puffed foods in neat little vials, from blueberries to carrots to potatoes.

Wolfgang Heiland is the man behind the machine -- the explosion puffing gun, a contraption that looks like a cross between a cannon and the Star Wars robot, R2D2. According to Heiland -- a taste tester of pies and muffins made with exploded blueberries -- there are only about eight or nine puffing guns in the world; the USDA houses one of them.

Heavy pressure is exerted onto semi-dried fruits or vegetables placed inside the heated gun chamber. The internal pressure actually makes the water in the fruit or vegetables "explode" (with a big bang, too), shooting the food about 100 feet per second from the gun down a 40-foot tunnel. The explosion-puffed food ends up in a trough, slightly shriveled and leeched of moisture. Some explosion-puffed foods can be rehydrated after a year or more.

ERRC has recently been approached by domestic mushroom producers who are eager to increase their market internationally, possibly with this process, and Heiland says he has experimented with explosion puffing of everything from tobacco leaves to chicken necks. (The object of explosion puffing the chicken necks was to see if the meat could be blown from the bones. Chicken neck meat is manually removed to make baby food, according to Heiland. In any event, it didn't work.)

Although the process is nothing new -- the explosion puffing gun was built in 1964 -- it has yet to spark widespread interest in industry. Heiland says a market would have to be developed for it, and that frozen foods may already fill that need. Chances are too, that irradiated foods will someday take charge for both.

Question: How can the shelf life of government-owned cheese be extended?

Simple answer: by freezing it. It's more complicated than just sticking the stuff in the deep freeze, though, and that's why Joseph Flanagan and Heiland use a "cheese machine." That's also why they have a "cheese room," a walk-in refrigerator full of five-pound blocks of processed American cheese.

The stainless steel contraption -- which is really a facsimile of a commercial cheese processor, infant size (it processes seven pounds of cheese, whereas commercial outfits can process up to 1,000 pounds, according to Flanagan) -- will help the two scientists experiment with processing frozen cheese, to fine tune the process.

According to Flanagan, processed American cheese is made from cheddar cheese, the most abundantly produced cheese in the U.S. But most cheddar cheese is processed into American before it starts to sharpen and age -- or before it's about six months old. (Schoolchildren don't like cheese that's too sharp, according to Heiland.) So the object is to freeze the cheddar cheese when it's young, to suspend it. Like the Iceman, once it's frozen, it won't age.

Their research will include making processed cheese from different percentages of frozen cheese and refrigerated cheese (30 percent frozen, 50 percent frozen, even 100 percent frozen cheese), determining exactly how long cheese can be frozen so that it still makes an acceptable product, to make sure the finished cheese made from frozen cheddar doesn't end up being too chewy and that it melts properly. (In fact, their experiments thus far have included making grilled cheese sandwiches and cheese sauces with different batches of the cheese. Some of the batches made from a combination of frozen and unfrozen cheese didn't melt that well, but the taste was fine, according to Flanagan.)

Question: Could cows ultimately be bred to produce skim milk?

The cows are in Beltsville, but some of their mammary glands are with ERRC scientist Harry Farrell. Strange as the image may seem, Farrell periodically drives down to the USDA research farm and transports the frozen tissues back to his Philadelphia lab.

Farrell is analyzing the lactating cell of a cow. He is trying to find out the mechanisms in which fat and protein are produced, so that they may someday be altered to produce milk that is lower in fat but still high in protein.

The two components, explains Farrell, sitting in his office with cow pictures and cans of goat's milk, have a high correlation. That means that when a cow produces milk that is high in fat, it is also high in protein. The reverse is also true. Low fat, low protein. Farrell wants to uncouple them.

He figures he'd better, considering the trends. Consumers are continuing to demand low-fat and skim milk. And all that excess cream being shaved off the whole milk that is eventually made into skim milk is being used to make butter. Farrell anticipates that combined with consumer interest in margarine, we could end up with a butter surplus.

Presently, producers are paid more for milk that contains more fat. If it comes to fruition, Farrell's findings could someday shift the entire economic incentive of dairy producers.