LATE-NIGHT MUNCHIES? BREAK OUT THE THREE-YEAR-OLD PIZZA AND MONTHS-OLD GUACAMOLE - Combat-Ready Kitchen: How the U.S. Military Shapes the Way You Eat(2015)

Combat-Ready Kitchen: How the U.S. Military Shapes the Way You Eat (2015)

Chapter 11

LATE-NIGHT MUNCHIES? BREAK OUT THE THREE-YEAR-OLD PIZZA AND MONTHS-OLD GUACAMOLE

THE SACRED RITE OF TEENAGE SNACKING

I’m dreaming. Striding through a familiar city—New York, Quito, Boston? I’m free, happy, energized. (Is it a bad sign that my nightly REMs are the best part of my life?) There’s a smell. Smoke. Something’s burning.

“Amalia!”

I dash downstairs. A “homemade” quesadilla—presliced cheddar cheese between two flour tortillas from a plastic bag stored at room temperature—is merrily singeing in a frying pan. Strewn on the counters are other remnants of her feast, which seems to be some sort of exercise in extreme carb loading: a mostly crumbs bag of tortilla chips; a tub of ready-to-eat guacamole, a large hole carefully excavated from under its barely opened plastic film; an empty Oreo cookie tray (she has, as always, discovered her younger sisters’ secret stash); and, for good measure, two dry and cold pieces of white toast. From the living room drifts the sound of canned laughter where Amalia’s ensconced on the couch, simultaneously texting, Facebooking, and streaming a video on the large-screen TV. It’s three o’clock in the morning.

There were times when I would have scolded her—the kitchen mess, the late hour, the poor diet, not to mention the possibility of burning down the house. But I don’t. She’s eighteen, home from college, fully launched along that fragile arc between childhood dependence and adult responsibility. Sometimes the best thing you can do as a parent is back off and let them grow up on their own. Besides, why sour another person’s moment of happiness, short and hard-won as these are wont to be? I sigh and turn off the burner.

THE ADOLESCENT APPETITE IS NOTORIOUS. In times gone by, this meant extra helpings at meals and late-night pantry raids. Today, when most kids have their own debit cards, it often means a nonstop diet of the junkiest junk food out there, plucked from the shelves of the nearest 7-Eleven or Casey’s General Store—chips, candy, frozen burritos, and that perennial favorite, pints of ice cream laden with mix-ins. But there’s now hope that the teenage munchies can be assuaged in a slightly more wholesome fashion. Hurdle technology and high-pressure processing, new preservation approaches adopted or developed by the army, may aid parents in keeping their offspring cocooned in the family room, lulled with limitless quantities of ready-to-eat, room-temperature edibles—pizza, sandwiches, even guacamole and salsa. These new foods have minimal storage requirements, which means that they can be buried in closets, piled in garages, and stacked by the case in basements for months or even years. Refrigerated items can linger for months, their glowing gemstone hues almost as permanent as, well, gems.

Since humankind first figured out how to save stores for winter or for voyages over land and sea, we’ve understood that preservation was a devil’s bargain: flavor and texture were sacrificed for staying power. Sometimes we grew to love the replacement—chewy beef jerkies, succulent hams, mouth-puckering pickles, lubricious conserves. But underlying our appreciation was the knowledge that there were no other choices. Shelf-stable food was dried, salted, sugared, pickled, fermented, or smoked. The holy grail of food preservation, juicy food that didn’t rely on an abundance of salt, sugar, or acid for longevity, was unthinkable until around 1800, when Nicolas Appert discovered canning. The moist contents, cooked and stored in hermetically sealed glass or tin, revolutionized our larders. But it would be almost another two hundred years before techniques appeared that could maintain the vivid colors, honest flavors, and crisp or gooey (or both) textures of recently harvested and just-prepared foods. This special new category of edibles even has its own delightfully mind-bending adjective, “fresh-like” (mind-bending because a meaning of fresh is “not preserved”).

IN THE EARLY 1960s LOTHAR LEISTNER, a scientist from the German Federal Center for Meat Research, spent a few years at Iowa State University. He apprenticed with John Ayres, an expert in the ways good food went bad, researching “the microbiology of cured meats, particularly that of ham and sausages” for the German army. He may also have been collaborating on his other specialty, mycotoxicology. According to the journal Wissenschaft und Frieden—a sort of German Union of Concerned Scientists, but with more humanities types—Leistner’s laboratory would later develop production capabilities for four of the most lethal fungal metabolites. His publication record of the era reflects the possible dual nature of his assignment. In one journal, he describes the role of Penicillium in fermented sausages and, in another, its synthesis of the deadly poison ochratoxin (the latter piece was coauthored with the USDA scientist Dorothy Fennell, the Quartermaster Corps’ foremost expert on fungi). Not that the fine—at times, nonexistent—line between harnessing knowledge for good or for evil should surprise anyone.

On the white-hat side of the ledger, we can probably chalk up Leistner’s work to understand preservation and spoilage of traditional preserved meats: “Perhaps the first stimulation came during my research work at the Iowa State University in Ames (1963-1966), when my director, Dr. John Ayres, informed me about the work published in Australia on the importance of water activity for the preservation of food. But in my thinking, it was not only the water activity value, but the influence of several ‘hurdles’ which caused the preservation of foods, and thus the idea of hurdle technology slowly emerged.”

Slowly indeed. It would be another decade before he breathed a word to anyone. In the meantime, Leistner continued working with Ayres, a regular contractor for the Quartermaster Food and Container Institute who often presented at conferences on yeasts and molds in preserved meats. In 1966 Leistner returned to Germany, where he “started a research project on yeasts in fermented sausages. In a way it is an extension of my work at Iowa State, but now we would like to look more closely into the correlation of yeasts to the water activity, redox potential [abbreviated Eh, the tendency to gain or lose electrons], and flavor of meats.” By the 1970s he and a partner at the Federal Center for Meat Research, the microbiologist Wolfgang Rödel, were hard at work developing meat products for the German military. “The main requirements of the Germany Army were as follows: meat products should be recommended for army provisions which have fresh product characteristics and remain tasty, stable, and safe for at least 6 days at 30°C [86ºF]. Refrigeration should not be required because these rations are to be used during military exercises.” In 1976 Leistner, along with his colleague Rödel, published his first piece describing the concept of the hurdle effect.

It was one of those ideas that seem obvious, yet no one had come up with it before. Leistner observed that none of the steps that go into the traditional recipe for curing a porcine hindquarter would be sufficient to halt microbial infestation by itself, but together they somehow produced prosciutto di parma, jamón serrano, Westfälischer Schinken, or Smithfield ham, and proposed a way to explain their synergy. To understand his theory and some of the most common hurdles, let’s return to the Roman Empire, which counts among its most significant achievements the spreading far and wide—if not the actual invention; that honor goes to the Celts—of the savory ham, along with Christianity, indoor plumbing, and socks. In fact, let’s break down this family recipe given by Cato the Elder, a statesman and gentleman farmer, in his treatise De Agricultura, the earliest surviving work of Latin prose.

The first two hurdles to microbial spoilage—although, of course, it would be close to a couple millennia before we discovered microbes—would have seemed self-evident to Cato, so they are not mentioned in his instructions. The first is chilling. In agrarian societies, hams are traditionally made in late fall and winter, when cool, but not freezing, temperatures slow microbial reproduction. After scalding, the carcass is hung overnight, which allows blood and bodily fluids to drain and then permits rigor mortis to set in. This brings on the second hurdle, a lowering of pH, brought about as the metabolic pathway that requires oxygen (aerobic metabolism) halts and the pathway that does not (anaerobic metabolism) continues for a while longer, causing a buildup of lactic acid. (In live tissue, lactic acid is regularly removed.) This increase in acidity lowers the pH to between 4.5 and 5.6, reducing the water-binding capacity of protein so there is more “free” water to expel. Now for Cato’s recipe:

You should salt hams in the following manner, in a jar or large pot: When you have bought the hams cut off the hocks. Allow a half-modius of ground Roman salt to each ham. Spread salt on the bottom of the jar or pot; then lay a ham, with the skin facing downwards, and cover the whole with salt. Place another ham over it and cover in the same way, taking care that meat does not touch meat. Continue in the same way until all are covered. When you have arranged them all, spread salt above so that the meat shall not show, and level the whole. When they have remained five days in the salt remove them all with their own salt. Place at the bottom those which had been on top before, covering and arranging them as before.

Hurdles three and four are all about lowering water activity through both chemical and mechanical means. Salt diffuses into the inter- and intracellular fluid of the meat, binding up water molecules and reducing osmotic pressure. To maintain equilibrium, water leaches out of cells, and eventually out of the meat. Piling the pig legs puts pressure on those lower down, compressing tissue and pushing out additional water. A midcycle rearrangement ensures equal treatment for all, resulting in even more expelled water. After almost two weeks of waiting, Cato brings us through hurdles five through seven in rapid succession.

Twelve days later take them out finally, brush off all the salt, and hang them for two days in a draught. On the third day clean them thoroughly with a sponge and rub with oil.

This hurdle—sponging clean the hams and coating them with oil—removes mold and prevents new patches from forming.

Hang them in smoke for two days—

Smoke is an antimicrobial. The cloud of hot particulate matter hovering over burning wood contains phenols, carbonyls, and organic acids, all of which alter the surface of the meat, making it more difficult for microorganisms to proliferate.

—and the third day take them down, rub with a mixture of oil and vinegar,—

Vinegar is another antimicrobial; it contains acetic acid, which kills bacteria and fungi. Oil creates a lipid barrier so new microorganisms cannot enter.

—and hang in the meat-house. No moths or worms will touch them.1

The final hurdle? Time. Just forget about your ham—for months. Air-drying, especially during dry and cool weather, extracts even more water, concentrates flavor, and forms a protective crust.

LEISTNER’S REALIZATION SOME TWO THOUSAND YEARS after Cato wrote his instructions that food safety and stable shelf life could be achieved by a number of mild factors working together may have been inspired by his knowledge of culinary traditions, but his theory about how the hurdle concept worked relied on the most modern microbiology. Since Van Leeuwenhoek first spotted something wiggling under his lenses in 1675, improvements in microscopy have advanced our knowledge of cells—and the organisms made up of them—from a long shot to an extreme close-up. For the bacteria that inhabit food, this has meant a journey from Pasteur’s eureka moment with the vino—“Hey! Those little critters are what’s turning my Châteauneuf-du-Pape into tarnish remover”—through the decades-long toil of hundreds of bacteriologists who, like police sketch artists, pieced together elaborate profiles of the most troublesome species, to the modern-day voyeurism of microbiologists mapping out the activity of cell organelles molecule by molecule. Building on all this, Leistner articulated a new, subtler way to kill microbes. Like CIA assassins trained to elude detection, food technologists could carefully manipulate multiple low-level environmental stressors rather than rely on a single easy-to-trace murder weapon.

The reason hurdle works has to do with homeostasis, a cell’s need to provide a stable environment for its inner workings. For example, temperature is vital for human cells: a few degrees up or down is the difference between life and death. Bacteria are much more forgiving with the weather, but many—although not all—are very sensitive to pH and osmotic pressure, both of which affect transport of materials in and out of the cell. Damage to the membrane alters the pumping mechanisms that maintain equilibrium, which can cause the cell to deflate or blow up. Other changes that cause irreversible harm are alterations to microbial DNA and enzymes. So-called sublethal damage is central to the hurdle technology concept. Wounded cells struggle to continue to function and to heal themselves. This depletes their energy stores, weakening them against the next assault, a process called metabolic exhaustion. Think of it as akin to shooting out your bacteria’s kneecaps in a remote area—they don’t die from blood loss, but from hunger and fatigue as they crawl around seeking help.

Hurdle technology also takes an ingenious approach to decimating one of the most durable life-forms on the planet, the bacterial spore, by creating a suboptimal environment—so even if it germinates, it doesn’t survive for long. The outcome is like when you bring home one of those window-garden kits, plant the seeds, watch them sprout, and then forget to water them: a potful of crunchy brown tendrils. Of course, bacteria are wily buggers, and many unleash specialized survival mechanisms when confronted with a stressful environment—for example, poisonous shock proteins—or simply become even more resistant to other modes of attack. Nonetheless, the principles of hurdle technology, when managed correctly, can compensate for these virulent curveballs. As Leistner puts it:

A synergistic effect could be achieved if the hurdles in a food hit, at the same time, different targets within the microbial cells (e.g., cell membrane, DNA, enzyme systems related to pH, aw, Eh etc.) and thus disturb the homeostasis of the microorganisms present in several respects. If so, the repair of homeostasis as well as the activation of “stress shock proteins” become more difficult. Therefore, employing simultaneously different hurdles in the preservation of a particular food should lead to optimal stability.2

HOW THE NATICK CENTER HEARD about the hurdle concept remains murky. Two of the key scientists who may have had contact with Lothar Leistner or exposure to his ideas, Irwin Taub and Dan Berkowitz, have since died, leaving those on the periphery to guess. “I’m sure Dr. Taub knew of him. Whether he actually knew him and contacted him in person, I can’t tell you,” says Patrick Dunne, a retired Natick senior scientist. Lauren Oleksyk, the leader of the Food Processing, Engineering and Technology Team, says Berkowitz, her boss, never mentioned Leistner, and “he never called it hurdle technology.” The practice itself is ancient. In the words of Michelle Richardson, the Natick food scientist with the most experience working with hurdle-based products, “If you look at the mummies, when they did the mummification, that was hurdle technology. They used chemicals, they used acids, they used several different methods to actually preserve the body.” Because it’s been around for such a long time, it’s sometimes difficult for people to differentiate between the traditional use of the approach and its deliberate application, which includes an understanding and manipulation of the underlying biochemistry. But somehow, by the early 1990s, Natick had incorporated hurdle technology into its plans for creating microbiologically safe, shelf-stable foods.

Leistner was invited to Food Preservation 2000, a 1993 conference at the Natick Center, which assembled speakers on a host of new ideas about how to preserve food thermally and, increasingly, nonthermally. Soon after, the scientist, no slouch when it came to tooting his own horn, had the German army print up a booklet with the results of his study on “minimally processed, ready-to-eat, ambient-stable meat products for army provisions” and mailed it to five thousand food scientists and technologists around the world, to ensure that “these data became generally available.” There was a snag, however. The publication was in German, an obstacle Leister was confident could be surmounted with the booklet’s “many color pictures.” He also began a concerted campaign to get the word out, publishing articles on the hurdle concept in Food Research International (1992), Journal of Food Engineering (1994), Trends in Food Science & Technology (1995), and the International Journal of Food Microbiology (1995).

Natick was one of the technology’s earliest adopters and continues to be one of its most enthusiastic users. The Combat Feeding scientists and technologists immediately saw hurdle’s usefulness to create moist items that could be stored at room temperature without loading them up with preservatives. Their first foray into hurdle technology was pound cake, but soon after that they began to work on the three-year shelf-stable sandwich, a difficult feat because the varying water contents of the different components of the sandwich tended to migrate, creating a limp and dispiriting pile. “Look at our shelf-stable sandwich; … for example, one of our sandwiches is pepperoni—that’s a fermented product and the pH is intentionally lowered,” explains Richardson. “In our bread, we have the yeast, which ferments and lowers the pH there, but in some of our formulations we actually add some acids to the bread to further lower the pH. It’s not just the water activity; it’s a combination of the water activity and the pH. We also add ingredients. Some of our yeasts are cured, so you have nitrite, which also has some antimicrobial activity. The packaging itself is another hurdle because it prevents moisture and gases from going inside the pouch. We put a scavenger in there, which decreases the oxygen in the headspace of the package. The organisms require oxygen, so that’s a hurdle as well. We’re looking at all of these together.”

The shelf-stable sandwich took seventeen years from inception to its first use in rations in Iraq and Afghanistan in 2007. Gerry Darsch, the former director of the DOD Combat Feeding Directorate, explains, “We took the concept of hurdle technology and we pushed the limits … really ran with [it], recognizing its capacity to expand the variety and quality of products and to manage complex food matrices… . Most of our entrées are wet pack, but all of the shelf-stable pocket sandwiches use hurdle technology… . By modifying and expanding on the opportunities that hurdle technology provides, we were able to insert a whole family of products into the ration.”

Hurdle can be used with all sorts of traditional food products and processes, but where it really makes a difference is with storing uncooked foods at room temperature, especially those like the army’s line of sandwiches, pockets, and pizzas that have multiple ingredients of different moisture contents—dry crust, wet tomato sauce, moist cheese. In fact, the army has already developed a shelf-stable pizza—crust and sauce separated by a basil-flavored nanofilm, which should make soldiers very happy, because over the years it’s been their most-requested item. On supermarket shelves, hurdle technology is everywhere—and nowhere, as most food technologists apply its principles without calling it by name. According to Kathryn Kotula, a food industry consultant who wrote a piece entitled “Interesting Forgotten Research” on hurdle technology for a food-science society newsletter, “Dr. Leistner’s work is used very, very widely. So widely, in fact, that younger people probably do not know its origins.”

IN A VACUUM, NO ONE HEARS YOU SCREAM (for argument’s sake, we’ll assume you’re receiving intravenous oxygen). Without molecules to transmit sound, a wavelike disturbance of the air, it’s just you, your Munchian grimace, and a vast silence. But once outside of the chamber, it’s a different story. Molecules are bouncing around everywhere, responding to minute changes in temperature, concentration, mix, and volume. The force they generate and that acts on them is called pressure. Pressures can be small, like the perturbations of sound, measurable in nanopascals. (Pascal was the genius philosopher, mathematician, and scientist who insisted that vacuums do too exist.) They can be huge, such as the mammoth pressure at the center of a collapsed neutron star, estimated at from a decillion to an undecillion pascals (that’s thirty-three to thirty-six zeros). Or they can be in-between; for example, a new food-preservation technique called high-pressure processing, which generally uses between three hundred million and eight hundred million pascals—imagine twenty minivans stacked on a penny—to obliterate the microbes in your edibles.

The food doesn’t become a compressed inedible mass because of the magic of liquid water. In its fluid state, the molecules are about as close together as they can be at sea level (they are farther apart in ice, which is why you shouldn’t forget about a bottle of wine chilling in the freezer). How does a high-pressure food-processing machine work? The food is encased in a sealed flexible package and placed inside a pressure vessel. The vessel is closed and water is pumped in until the desired pressure is obtained. The food is held at this pressure for a few minutes, generally about five, after which the vessel is decompressed and opened. (Liquid water does change volume somewhat in response to increasing external pressure, and high-moisture foods react in a similar way, compressing up to 15-20 percent. After treatment, however, the food returns to its normal volume.) In the process, some of the less powerful bonds (hydrogen, ionic, and others) break, unfolding or disassembling bigger molecules (proteins, starches, and others)—this also happens in cooking. On the other hand, the double-strength covalent bonds hold, leaving intact important smaller molecules such as vitamins, flavor compounds, and pigments. All these transformations are just fine for the food, but for the bacteria that may lurk inside, it means finit: cell walls spring leaks, genetic instruction manuals unravel, and their enzymes and other proteins can coagulate.

As a food-preservation technique, high-pressure processing is a late bloomer. It was discovered just before the turn of the twentieth century: in 1895, a French scientist, H. Roger, found that E. coli, Staphylococcus aureus, and anthrax bacteria could be killed with high pressure (although, even then, he noted that spores apparently still germinated, a problem that persists to this day);3 four years later, Bert Hite, of West Virginia University’s Agricultural Experiment Station, showed that raw milk processed with high pressure kept fresh for up to four days longer than untreated milk. While promising, research on the technique was abandoned a couple of decades later when Clarence Birdseye’s invention flash freezing came along, use of which became widespread once the price of a refrigerator declined—thanks to Freon—in the 1930s. Meanwhile, the other stalwart of the modern larder, canned goods, continued to be improved, although never to the point that anyone would mistake the contents of a tin of Chicken of the Sea for a freshly seared tuna steak. Advances in knowledge and equipment for retort processing inched along, but so did the availability of high-quality fresh food. Consumers’ expectations grew—and their tolerance for the mushy textures, overcooked flavors, and dull hues of canned food waned.

It was obvious that Appert’s world-changing invention needed an understudy. But what? Overseen by the Quartermaster Food and Container Institute in Chicago and then the Natick Labs, the U.S. Army bet big and it bet wrong: after World War II, the government poured a scandalous number of millions of dollars into radiation sterilization, probably the biggest food research flop there ever was. In the words of Dan Farkas, an MIT-educated food scientist who spent the 1950s and 1960s as a civilian contractor on the project, “Food irradiation was the perfect case study of how not to transfer technology to the general public. There were problems at every turn. Consumers rejected it. The FDA was concerned it would be toxic. The packaging had issues.” Eventually, the Natick Center’s cobalt-60 irradiator was mothballed, and the scientists and engineers who’d spent a decade or more of their careers on a failed-to-launch technology were urged to find new homes—pronto. Farkas ended up at the University of Delaware.

Flummoxed about how to proceed, he did what all engineers do in times of extreme stress—he made a matrix. Across the top Farkas put all the major food-preservation techniques, and along the side, the various ways food could spoil, become poisonous, or deteriorate. He perused his table. Aha! A mechanism had been waiting quietly in a dusty corner while all the others—heat, cold, chemicals, and water activity—had had their turn. Farkas would pick up where the last scientists left off (the physicist and high-pressure expert Percy Bridgman had coagulated egg white in 1914, and a couple of small projects had been conducted in the late 1960s and early 1970s), but he would go a lot further. He would figure out a way to make high-pressure processing (HPP) commercially viable. And that would start where all good business starts, with the right equipment. Resolving this would turn out to be the biggest obstacle to converting high pressure from an impressive laboratory trick into a real alternative to thermal processing. As Farkas describes it,

Dietrich Knorr was at the University of Delaware with me. He’d come over from Germany in the early eighties and joined the faculty, along with Dallas Hoover. The three of us decided to go into it [high-pressure processing] because we needed research dollars… . The only thing needed was a high-pressure unit. Parker Autoclave Engineers in Erie, Pennsylvania, made all the tubing and valves and so forth. What we would pitch to them was, that while there was a lot of interest in high-pressure metal work, it was a cyclical business—in boom times, a lot of jet engines would be built—but then … We suggested that the food industry would be a real … user of high-pressure equipment and they actually loaned us our first unit. We could roll it into the lab, hook it up, and press foods.

They spent several years figuring out the nitty-gritty, such as how much pressure and what length of time killed various bacteria in different edibles. In 1987 Farkas left for a three-year hiatus at the Campbell Soup Company, after which he moved to the University of Oregon, having been lured by a beautiful pilot plant and the chairmanship of the department. But he continued working with his University of Delaware colleagues Hoover, who was still stateside, and Knorr, who’d departed for Germany.

When the team felt that they were ready, Farkas didn’t waste any time. He contacted Patrick Dunne, then a program manager at the Natick Center, whom he knew from his contracting days, his annual two-week reservist’s stint in Natick’s food labs, and his participation in the Natick Center’s advisory board. “As soon as we saw really good microbial results at Delaware, Dallas Hoover and I took off to Natick. It seemed to be a no-brainer to go to them and show them what high pressure could do. And Dunne had a vision of taking on the new technology that could result in a better-quality food. After hearing our proposal, Pat was instrumental in building the research program that resulted in the development of [high-pressure-treated] military rations.”

Taking to heart the lessons learned from the irradiation program on how not to get an exotic technology approved and adopted, Dunne got right to work. With some earmarked funds for new and novel nonthermal processes, he issued a request for a proposal under Natick’s general-purpose contract vehicle, the Broad Agency Agreement, commissioning two projects: more microbiological studies at the University of Delaware and some product development work at Oregon with Farkas. By 1998 the army laboratory had concocted a very respectable all-HPP repast: seafood Creole, vegetarian pasta with tomato sauce, and yogurt with blueberries. All these foods were carefully formulated to be acidic, which made them inhospitable to most spore-forming pathogenic bacteria, including the difficult-to-eradicate botulinum, and freed them from the need for FDA approval (this is required only for “canned” low-acid and acidified foods). During the same time period, Natick moved forward on the equipment front and awarded contracts to two small companies, Avure Technologies, a spin-off from the Swedish and Swiss power and industrial machinery company ABB, and Elmhurst Research, Inc., an engineering firm, to come up with designs for machines that wouldn’t, as the current ones were doing, fall apart after one hundred cycles. Durability wasn’t important when the technique was used to manufacture small quantities of high-margin metal work (for example, jet engines), but for the food industry, where throughput is high and margins low, it was crucial.

The army could now kill all vegetative bacteria in acid foods and had sturdy processing equipment (the Elmhurst model recycled old six-inch cannon tubes—built to withstand powerful explosives—as the pressure vessel), but it wanted more. “We thought high pressure was pretty ripe to get expanded in the next direction,” says Dunne. That direction was the elusive comfort foods—specifically, mashed potatoes—clamored for by servicemen and -women everywhere, but which until then Natick had been unable to provide, at least in a version soldiers actually enjoyed. Because the starchy side is low in acid, it must be terribly overcooked—held at high heat for a very long time—to kill any bacterial spores that could germinate during storage. Any treatment other than thermal sterilization would require regulatory approval.

ALTHOUGH FDA ACCEPTANCE had been exceedingly difficult to win for Natick’s food irradiation program, Dunne was optimistic. “The task was to build this, get a shelf-stable, low-acid food, and file and get the process approved with the FDA.” Taking advantage of the Dual Use Science & Technology (DUST) consortium, a new congressionally enabled DOD cooperative research vehicle that allowed government and industry to split the costs, he put together a heavy-hitting team. Avure was the prime contractor. The other companies included Hormel, Unilever, Basic American Foods, ConAgra, Baxter International, General Mills, and Mars/Masterfoods. Also part of the group was the National Center for Food Safety and Technology (NCFST, now the Institute for Food Safety and Health), a joint venture between the Illinois Institute of Technology, the food industry, and, hmm, the FDA.

The first step was to build a demonstration vessel that would use both heat and pressure for a short period—a process that came to be known as pressure-assisted thermal sterilization (PATS)—and show that it was as safe as traditional pasteurization. As anyone with a weaponizable pot-wielding great-granny knows, pressure and heat combine to drastically reduce cook time. For example, army mashed potatoes made the traditional way in a retort machine are cooked at 250°F for eighty minutes; PATS-sterilized and -preserved spuds take just twelve. It took Avure several years to successfully develop the new machines, which, at thirty-five liters, were the most capacious to date.

Then the consortium, as Dunne circumspectly puts it, “set up a [demonstration] subcontract with Illinois Institute of Technology, which happens to be a site operated by them for the FDA as the FDA’s research center in food processing. They were an ideal place [to do the research], because the regulatory people who make decisions on novel processes were colocated there… . They are a resource [we] can bounce [off] or talk things [through] with. We [find] it important for [our] processing authority to walk steps through the research design before [we] go rather than just handing them [the FDA] a big document.”

Still, HPP had no track record, minimal theoretical underpinnings, and lamentably few safety studies. The FDA’s most reliable yardstick—the botulinum kill—could not be applied. To get approval for its low-acid items, the army and its collaborators would need to show that HPP and PATS were as effective as heat pasteurization, and the FDA would have to evaluate their petition using a food safety framework that permitted nontraditional sterilization techniques. In 1998 the FDA hired the Institute of Food Technologists to vet the science and safety of alternative food-processing techniques. The work on HPP was done by the Physical Processes Subpanel—three Natick contractors, Farkas, Hoover, and Jozef Kokini, a longtime army collaborator from Rutgers University—and reviewed by, among others, Dunne, staff from the NCFST, and people associated with the project, including the consultant who put together the FDA filing, Larry Keener.

Meanwhile, high-pressure processing of refrigerated acid or acidified foods was really starting to take off in the private sector. “Natick pump priming jump-started the use of high-pressure processing by food companies,” says Farkas. Fresh guacamole, that most finicky and delicious dip, was the first HPP-treated food on the American market. In the late 1980s and early 1990s, Don Bowden, the owner of several Mexican restaurant chains in Texas, was looking for a way to reduce the cost and extend the life of the guacamole he served—avocados are easily bruised in shipment, and, once opened, natural enzymes quickly turn the pulp from bright green to brown. He approached Chuck Sizer, who at the time was the research manager at food packaging and processing giant Tetra Pak (he would later become director of the NCFST during the early years of its involvement with HPP). They gave thermal pasteurization a whirl. “It came back looking like pea soup,” says Sizer. “The wrong color. The wrong texture. And it just didn’t taste good.” Eventually the pair ended up trying out the floor model at the Ohio offices of ABB.

The work of Farkas, Hoover, and Knorr earlier in the decade gave the scientist and the entrepreneur confidence. “At that time the literature was good enough to know that it had an effect on the microbiology and log reduction [the number of organisms reduced relative to the starting number] of pathogens,” says Sizer. The process worked “wonderfully,” leaving the avocado green, creamy, and fresh for up to a month. The new preservation technique revolutionized Bowden’s business, allowing him to outsource the whole process to Mexico, and turned him, under the Wholly Guacamole trademark, into a profitable supermarket supplier. “This was the ideal product and for several years it was the poster child for high-pressure processing,” says Farkas. “They just kept building plants—in Mexico, Peru, Chile… .”

Soon there were competitors—and new HPP products. Fresherized Foods, the company that made Wholly Guacamole, expanded its product line to avocado smoothies, salsas, and meal kits. Tropicana put a toe in the water—investing a million dollars for the exclusive rights to purchase the new HPP equipment Avure was working on for the DUST consortium, but later withdrew because of performance issues and after initial projections suggested it wasn’t cost-effective for supermarket orange juice. However, at the opposite end of the juice market, which was inhabited by sleek, single-portion, fresh-squeezed fruit beverages going for four or five dollars a pop, a few companies began experimenting with the technique because it allowed them to kill dangerous microbes without flavor-changing heat sterilization.

THE TURNING POINT IN THE ACCEPTANCE of HPP as a viable food sterilization technique came, as it so often does, after a crisis. In 1996 there had been an E. coli O157:H7 outbreak that was linked to Odwalla apple juice. Fourteen children had developed hemolytic uremic syndrome, which destroys red blood cells, and one, a sixteen-month-old girl, died. A criminal suit was filed by the FDA and multiple product liability suits were filed on behalf of the victims. (A particularly damning piece of evidence was a letter from the army to Odwalla rejecting it as a vendor for sanitary deficiencies.)4 Five years later (lengthy lag times are not uncommon for the agency), the FDA considered, but rejected, mandating heat pasteurization for all fresh-squeezed, untreated juice, opting instead to require that manufacturers have a Hazard Analysis and Critical Control Points (HACCP) plan, the systems approach developed by Natick, Pillsbury, and NASA for the space program, which is flexible about processing methods as long as they ensure safety.

This was a major coup for Natick and its collaborators, because the decision was based, in part, both on the DUST work being done at the NCFST, which showed that alternative sterilization methods could be just as effective in deactivating bacteria, and on “Kinetics of Microbial Inactivation for Alternative Food Processing Technologies,” the white paper prepared for the FDA by the Natick-dominated IFT panel that explained why HPP worked. The FDA’s decision on fresh juice paved the way for two important and interrelated developments: hastening a paradigm shift by regulatory agencies to a preventive, quality-assurance approach to food safety rather than a reactive, inspection-based one (this was codified in the FDA’s Food Safety Modernization Act of 2010), and indicating its receptivity to approving the army’s new nontraditionally processed low-acid food.

The ruling also persuaded more juice makers, who were eager to preserve the just-squeezed taste without cooking the product, to turn to the new cold sterilization method. But the trickle turned into a tide in 2006, when the Hormel meat company launched the first of its Natural Choice products, a prosciutto ham; this “100% Natural. No Preservatives” line soon grew to include lunch meats, bacon, sausages, and chicken strips and is now one of the company’s biggest moneymakers. (The refrigerator case is a sweet spot in terms of profitability, because the markup per item is much greater.) Other deli products manufacturers, such as Oscar Mayer, and Tyson, soon followed suit. Anchored by the investment of the meat and meat products industries, true monoliths in the American economy, the future of high-pressure processing is all but assured.

Meanwhile, the PATS consortium was finalizing its FDA filing—this was done by a knowledgeable microbiologist known as a “process authority,” in this case, Larry Keener—and finishing its validation studies, which are detailed tests that show a process does what it’s supposed to do under various conditions. When the consortium finally presented its petition in September 2008, FDA approval, which often goes on for years, took just five months.

This breathtaking rapidity may have been due to our ever-improving understanding of the mechanisms of microbial deactivation and that a considerable amount of scientific footwork had been done to show the technology’s safety and effectiveness, but it’s hard not to wonder if the fact that HPP and PATS were the pet projects of a fellow federal agency (one whose rations mandate is to seed its favored technology in the consumer market) and that the gatekeeper was also a team member played a role. Prophetically, the FDA’s own Science Board had been concerned about the ethicality of exactly these types of cooperative arrangements, and discussed the topic in its October 1998 meeting:

Dr. Kipnis [professor of endocrinology]: Are there restricted limits by law as to how you can interact with this group?

Dr. Schwetz [FDA official]: No, not—for example, the two topics that I’m talking about are unrelated to a product per se; it’s a new technology. So in that case, that’s something that will flow through the approval systems without an awful lot of problem.

Dr. Kipnis: But new technologies are new products.

Dr. Schwetz: If it related to new products that come back to the FDA for approval, like in the Center for Devices, where we will see technologies of one kind or another, then it becomes a problem if we’re helping a company develop a technology and we become one of the inventors, coming into CDRH [the Center for Devices and Radiological Health] for approval. So you’re right, there are significant limits for us to be involved in this.

Dr. Nestle [professor of nutrition]: Could you tell us a little bit more about the kinds of partnerships that you’re seeking, because I’m very concerned about the potential for conflict of interest here. I just can’t think of anything that wouldn’t be a conflict of interest.5

Everything seems to have been done by the book, but there’s an unnerving circularity to the arrangement. So far, there’s no evidence that consumer health has been put at risk, although human safety studies on the new food-processing techniques are still scant. At any rate, the outcome was that just about any food—including meat, poultry, and eggs, the USDA’s domain—can now be high-pressure-processed. Gerry Darsch sums it up: “If we don’t get industry on board, particularly if it’s something relatively novel, it’s not going anywhere. We don’t want something military-specific.” And should you have any lingering doubts about whose baby this really is, the Natick Center’s recently retired Pat Dunne doesn’t. “Where I personally really made the market commercially—it’s refrigerated, extended-shelf-life foods.”