You ease open the refrigerator door to take stock after returning to town from your summer home. The situation isn't so grim after all: there's that romaine lettuce you bought six months ago, still looking fresh and crisp. A chunk of Parmesan, picked up--what year is this again? And down on the bottom shelf: vegetables of various vintages and, there it is, that nice piece of cooked, shrink-wrapped synthetic chicken. It has been in your refrigerator longer than some of your neckties have been in your closet. Just as you realize that the scratchiness in the back of your throat is not going away, you come across a little bottle of antiviral salad dressing. That clinches it. Chicken Caesar salad it is.

Although that scenario may sound a little strange, tomorrow's world of high-tech foods would most likely seem as fantastic to us as microwaves, frozen meals and today's wide selection of produce would have appeared to a cook just 50 years ago, let alone 100. Many of the details of how food will taste and look, and how it will be packaged and prepared, will depend on those most elusive of intangibles, consumer tastes and preferences. Nevertheless, several trends seem to be gathering momentum, offering glimpses of what and how we might be eating early in the next century.

One is the explosive growth lately in sales of dietary supplements and the advent of so-called functional foods, which contain additives that confer physiological benefits beyond simple nutrition. In addition, tasty new forms of protein--including steaks and fillets grown in chambers rather than as part of an animal--as well as packaging that lets produce breathe and treatments that kill harmful bacteria with radiation or pressure are all likely to be a part of the 21st-century dinner table.

Supercharged Food
ONE OF THE MOST REMARKABLE phenomena in nutrition in recent years is the rise of dietary supplements and, in particular, of "sports supplements" aimed at weight lifters and other physically active people. In 2005 Americans spent more than $21 billion on dietary supplements, according to Grant Ferrier, editor of the Nutrition Business Journal in San Diego. About $2.2 billion of that total was spent on sports nutrition.

Such supplements could be just the first entries in a burgeoning market for supercharged food. "Most of the sports supplements are designed to produce benefits centered on control of body composition and energy," says A. Scott Connelly, founder of Met-Rx Engineered Nutrition, now headquartered in Bohemia, N.Y. "People are realizing that the simple calorie theory of body fat control is hopelessly inadequate. For example, supplementing regular dietary intake with lean protein assists the body in burning fat," he maintains.

Connelly further notes that many staple foods such as rice and potatoes are poor sources of vitamins, minerals and other nutrients. Although nutritional supplement companies have long recognized this problem and marketed daily multivitamins and minerals to meet it, "I can tell you as a doctor that human beings don't like to take pills," he insists. "Probably less than 25 percent of people with high blood pressure comply with their prescription. Increasing nutrient density [of traditional foods] has to be a primary goal."

As an example, Connelly cites pizza, "the nutritional Antichrist." Met-Rx's nutritionists have experimented with the humble pizza, the quintessential food for the masses. Met-Rx's reengineered nine-inch pie has only 650 calories. Moreover, the enhanced slice contains 75 grams of a high-quality protein--about four times more than usual. It also has 160 percent of the recommended daily allowance of calcium and 300 percent more lycopene. This plant pigment, which gives the tomato its red color, is also an antioxidant that has been linked in some studies to reduced incidence of heart disease and prostate cancer.

Where might it all lead? If you are waiting for a nutrient-packed food pill, a favorite of 1950s science fiction, you will be disappointed. According to Connelly, food will have to be "in sync with current taste and texture preferences. We won't be successful in trying to get people to abandon their tastes for sweets and fats."

Immunity-Boosting Produce
ANOTHER PIECE OF EVIDENCE that the age of high-tech foods had begun was the 1999 introduction of the margarine Benecol. Clinical trials show that eaten regularly in sufficient quantities, the product's plant stanol esters can reduce the risk of heart disease by lowering levels of potentially harmful, low-density lipoproteins. The margarine is an example of a functional food or "nutraceutical," whose additives provide one or more specific health benefits beyond simple nutrition.

Such foodstuffs could be the basis of an industry raking in $34 billion by the year 2020, Ferrier predicts. Indeed, they are already carving out a sizable niche in Japan, he adds. Cutting cholesterol would only be the beginning; experts foresee products that would do anything from boosting your immune system to fighting seasonal allergies. For the seriously overweight, for example, there could be foods containing dietary hormones such as glucagon, which causes some people to feel full after eating modestly.

Suppose your doctor tells you, 15 years from now, that you have a mild form of diabetes. Rather than closely monitoring your food intake and blood sugar levels, as you would probably have to do today, you might be able to find everything you need to stay healthy in your local supermarket's health food section. No, not the dreaded row lined with organic granola and sprouts but rather an aisle with foods containing additives that, to continue our example, regulate insulin activity and keep your blood sugar under control.

According to John P. Troup, now at Novartis Nutrition Corporation in St. Louis, to produce an effective functional food scientists must "identify the mechanism in the body that is causing some response." That means identifying the individual proteins that carry out the process and then designing a molecule to enhance or discourage the response. Once made, such molecules could be used as food additives.

These foods won't be limited to a prescription aisle. Many common fruits or vegetables could be genetically engineered to produce vaccines for common childhood diseases. In fact, researchers at the Loma Linda University School of Medicine have already genetically engineered potatoes to produce trace amounts of a cholera toxin that could immunize the diner, helping his or her system to resist cholera bacteria.

"More and more, the supermarket is going to become a health care provider store, rather than just a place you buy your food," declares Theodore P. Labuza, professor of food science and engineering at the University of Minnesota. "These products are going to be put out in the produce section," he says, adding that "there's going to be a time when consumers are confused--are they buying food or a drug?"

Such claims could lead to confusion for consumers as early clinical and epidemiological studies report conflicting or confusing results. Labuza points to one study that reported that large volumes of beer are beneficial because of antioxidants in the hops. Another study concluded that voluminous amounts of coffee help to prevent cirrhosis of the liver. "It made me wonder if I should put my money into companies that make urinals," Labuza says.

But the foods also give doctors a potential tool. "The physician's prescription to lower cholesterol may read: 'Take these pills once a day and eat some stanol estercontaining yogurt for breakfast and lunch,'" Labuza says.

Although food will change, our nutritional requirements will not. Humans will always need protein, the stuff of our muscles, organs and other tissues. Chicken, beef and pork could continue to be our main sources, but many experts foresee a growing market share for others.

Protein powders, for example, are among the big sellers in the previously mentioned sports supplement category. Whey protein isolate has become popular in recent years, thanks to greatly improved methods of manufacture. Basically, whey is what remains of milk when its other main solid components, fat and casein, are coagulated into cheese curd. It was essentially a waste product of cheese making until someone noticed that it was extraordinarily high in protein and extremely low in fat and in lactose, which some people find irritating to the stomach.

Soy: It's What's for Dinner
THE ADVANTAGES OF POWDERS notwithstanding, it is hard to imagine most people doing without protein with more traditional textures. Some nutritionists see fish as the protein staple of the future. But Irena Chalmers, a food writer and professor at the Culinary Institute of America in Hyde Park, N.Y., is betting on soy. "It can be made into anything: any taste, any texture--crunchy or bland or squishy or slimy. It's going to be an enormous tool," she maintains.

As for animal protein, Morris A. Benjaminson has a dream: producing it without the animal. Benjaminson, a biology professor at the Touro College School of Health Sciences and president of Zymotech Enterprises in Bay Shore, N.Y., hopes to turn stem cells into meat. While working on a system to grow edible mushrooms from human waste for long-duration space missions, he recalls that "it occurred to me that not all astronauts will want to be vegetarians" (to say nothing of eating those mushrooms). A chicken coop in the cargo bay was obviously out of the question, so he came up with another idea: growing animal skeletal muscle tissue--a fillet or steak, in other words--in small chambers.

Benjaminson and his team have extracted stem cells from fish embryos and used them to grow muscle cells by stimulating them electrically, mechanically, hormonally and nutritionally. With enough tinkering and funding, Benjaminson thinks that soon he will be able to grow something that has the consistency and taste of filet mignon. So far he has worked mainly with fish muscle cells and has had some limited success in producing a tiny mass of tissue that looks, smells and cooks like a fish fillet. He believes that such a technique could mass-produce boneless chicken breasts for a fraction of the cost of a commercial chicken farm, without the salmonella and other harmful organisms that can exist on supermarket poultry.

Benjaminson is not the only one working in the field. Dutch researchers at Utrecht University are using pig stem cells to produce vat-grown pork. They hope to create minced meat that could be used in burgers, sausages and pizza toppings within the next couple of years.

Jason Matheny, a University of Maryland doctoral student who directs the nonprofit group New Harvest, envisions "meat sheets" composed of layers of animal muscle and fat cells. He believes that using inexpensive nutrients from plant or fungal sources could drive the price of vat-grown meat down to as little as 1 a pound. It could even be improved through the addition of omega-3 fatty acids and other heart-healthy ingredients.

Will vat-grown meat produce philosophical conundrums? Many vegetarians adopt the lifestyle for health reasons, but others do so because they object to exploitation of animals for food. "No animal is harmed here. This stuff is pretty much as guilt-free as you can get," says Jack William Bell, a Seattle software engineer and part-time futurist.

He points out that the technology could give rise to unexpected culinary choices. "Endangered species might no longer be taboo," Bell suggests. "What if we used cultures from endangered or even extinct species? Would it be okay to have Siberian tiger on a stick? Spotted owl nuggets? You could have that bowl of panda stew in good conscience!"

Clearly, in a world where a steak might come from a cow or a test tube and a head cold might be treated with a pill or a salad dressing, the consumer is going to need a little more help. Fortunately, grocery stores are becoming more interactive, with help not only for the confused but also for the harried.

Keeping It Fresh
IT IS UNLIKELY that on the shelves of tomorrow's high-tech, user-friendly grocery stores the tastier, healthier wares will be offered in the same old stifling packaging and wrappings used today. Take romaine lettuce. We've all seen its mysterious transformation: from a crisp, light delight to the taste buds to a repulsive sack of foul, brown goo after a couple of weeks in a standard plastic bag. Not so in the future, Labuza says.

The trouble with storing a head of lettuce in a garden-variety plastic bag is that the lettuce is still alive, taking in oxygen from its surroundings and using it to convert stored sugars to energy for growth and metabolism. In short order, the supply runs out. "When the oxygen level dips below a certain level, [the lettuce dies and] begins to rot," Labuza explains.

Preservation is best achieved by slowing down respiration, so that the vegetable uses its stores more slowly and lives longer. That depends in part on maintaining the oxygen level of the bag at an optimum level--lettuce stays crisp in an atmosphere of about 3 percent oxygen. The goal for the plastics industry is to produce a bag that takes in oxygen ("respires") at precisely the same rate that the vegetable or fruit does. Polymer scientists have already made some progress in this area. River Ranch Fresh Foods in Salinas, Calif., markets to growers a line of produce bags that have variable permeabilities to carbon dioxide and oxygen. The bags can increase shelf life up to 100 percent, depending on the fruit or vegetable, according to Sannai Gong, R&D manager at River Ranch.

Another approach is a new technology called SmartFresh. Marketed by AgroFresh in Spring House, Pa., the active ingredient neutralizes the effect of a natural gas called ethylene, which prompts fruit to ripen. By negating ethylene's effects, SmartFresh delays ripening and significantly increases a fruit's shelf life.

But ambient gases are only part of the problem. Meat doesn't last long in the presence of bacteria, and pathogens such as salmonella and some strains of Escherichia coli present a real hazard to consumers. One solution--irradiating food with high-energy particles--kills bacteria quickly and efficiently. Although the procedure has met with some consumer resistance, Connelly expects it to become an important technology. He envisions underground vaults filled with radioactive materials, rather like a walk-in x-ray machine: "You could drop in whole packaged food products and have them emerge stable," he asserts.

But if high-energy particles don't appeal, perhaps high pressure is more palatable. Although no one is quite sure how it works, Labuza says that pressures of 240 to 275 kilopascals (35 to 40 pounds per square inch) efficiently sterilize packaged food, apparently killing pathogenic bacteria by disrupting the function of DNA. "You take guacamole, put it in a plastic package and put it in a cylinder, fill it with water, and then use a piston to pressurize the whole system. In a matter of minutes, you can kill most of the spoilage and food-poisoning organisms," Labuza says.

Once sterilized, the food could be shielded from outside contamination by shrink-wrapped packaging with antibacterial molecules incorporated right into it. Thus sequestered, food should be well preserved from microbiological hazards, but it faces one other challenge: oxygen can infiltrate the packaging and cause it to become rancid. To block it, packagers have added "oxygen traps"--in some cases simply iron--that react with oxygen before it can attack the contents of the package. The payoff is packages of meat that could last several years unrefrigerated.

Whatever the future may bring, it seems certain to end the refrigerator biology projects that greet most returning travelers today. Slimy vegetables, rancid meat and nutritionally bankrupt starches could also be eliminated. And test-tube chicken could be the main course.

Will our taste buds be titillated? Or will manufacturers get caught up in a frenzy and make the same mistakes soy food producers made in the 1970s, sacrificing everything--including taste--for the sake of health benefits? Let's hope they do not, or the food of the future might be old-fashioned carry-out cheeseburgers and fries.

The Author
JIM KLING is a freelance science and technology writer in Bellingham, Wash. He writes frequently about biotechnology and drug discovery. Much of his focus is on how economic, regulatory and political forces influence the biotechnology industry. He also tries his hand at science fiction from time to time. Kling has mixed feelings about the idea of a synthetic fish fillet sandwich.