The most controversial area of food engineering is the one that remains farthest from fruition: The use of biotechnology to grow frost-proof fruits, durable tomatoes, high-protein beans--even cows that produce low-fat milk.
Scientists throughout the country are exploring the possibility of using the newly developed techniques of genetic engineering to improve the convenience, profitability and, occasionally, nutritional attributes of traditional foods.
So far, no such foods are on the market. But the U.S. Food and Drug Administration is reviewing four applications to sell enzymes, for use in food processing, that have been developed through recombinant DNA technology.
The techniques, first developed in the 1970s, involve transferring genes from one species to another. Researchers hope they can use those techniques to introduce desired traits into crops and animals.
Among the studies: Scientists are exploring the possibility of enhancing the methionine content of beans and the lysine content of corn. Methionine and lysine are important amino acids that are deficient in those crops. Enhancing the contents of those acids would improve the plants' nutritional value.
The U.S. Department of Agriculture is attempting to alter the genetic structure of wheat to improve the size and shape of loaves of bread. The aim is convenience, but USDA scientists say it is conceivable they might later consider nutritional improvements as well.
Tomatoes genetically engineered to ripen on the vine without turning mushy are being tested for eventual marketing. Researchers are also exploring the possibility of altering the genetic makeup of dairy cows to produce low-lactose or perhaps low-fat milk.
Precisely how such products would be regulated remains unclear.
FDA officials say that whether an artificially altered gene is a food additive subject to FDA scrutiny has yet to be determined. If it simply enhances an enzyme already inherent in the food, it may not fall within the FDA's jurisdiction, one FDA official says.
James Maryanski of the FDA's Center for Food Safety and Applied Nutrition says there are "some concerns" with genetically manipulated foods--for example, the risk of inadvertently increasing levels of natural plant toxins that could be harmful to humans.
"One of the things you have to realize is that food is not completely safe," says Maryanski, the center's coordinator for biotechnology. "Plants have many substances that allow them to defend themselves against disease and other adverse conditions."
That is precisely the concern of Jack Doyle of the Environmental Policy Institute in Washington. He and other skeptics fear that misguided "monkeying" with plant and animal genes could lead to "nutritional erosion" and other dangerous complications.
As an example, Doyle cites efforts in the 1960s to produce a better chipping potato through traditional cross-breeding, which does not involve genetic engineering. The breeding unintentionally altered the makeup of the potatoes in question, rendering them inedible and forcing their withdrawal from circulation.
"In some cases, there may be genetic baggage that comes in with genes from other exotic species," says Doyle, director of the agriculture and biotechnology project. "We need to really pay attention to inadvertent changes in nutritional characteristics."