What's Natural?

My question relates to packaged food products that say "natural flavorings" in the list of ingredients, but when I consult the table of nutrients no specifics are given. What are they adding and why don't they have to say what it is? Is it salt, enzymes or what? "Natural" is not the least bit enlightening as an adjective! My chemistry professor used to protest that everything on Earth is natural.

This chemistry professor agrees. If it isn't natural, what would it be? Supernatural?

My dictionary lists 14 meanings for the adjective natural, ranging from "not adopted" (for the parent of a child) to "neither sharped nor flatted" (for a musical note). So your confusion is perfectly . . . uh, natural.

Many consumers appear to believe that natural is a synonym for good or healthful, as opposed to anything made or processed by humans, which is inherently evil and harmful. But Nature hides many decidedly unfriendly chemicals in our foods. Consider, for example, that the chemical amygdalin, found in "natural" apricot and peach pits reacts with stomach acid to produce hydrogen cyanide, the lethal gas that has been used to execute convicted criminals. (Amygdalin is also known as Laetrile, a supposed cure for cancer promoted by a certain doctor in Mexico. The fact that the American Cancer Society has labeled Laetrile "quackery" hasn't stopped many Americans from traveling to Mexico for "treatment.") Moreover, many of the trace-amount chemicals responsible for the natural flavors of foods are so toxic that they would never be approved by the Food and Drug Administration for addition to foods.

To control the rampant use of the word natural on the labels of food products, the FDA has come up with a definition, at least in the context of flavor additives. (The ubiquitous "all natural," which manufacturers use to sell everything from cosmetics to bathroom cleaners, is not regulated and probably cannot be, because the words "all natural" can mean almost anything the manufacturer wants them to mean -- including nothing at all.)

The official FDA definition of natural flavoring is published in the Code of Federal Regulations (21CFR101.22) in the form of more than 100 words that meticulously plug every conceivable loophole.

In simple terms, a natural flavor is defined as a substance extracted, distilled or otherwise derived from plant or animal matter, either directly from the matter itself or after it has been roasted, heated or fermented. Note the inclusion of "animal matter" in this definition, an important revelation to vegetarians and those who adhere to the kosher segregation of meat from dairy products. But animals are just as natural as plants, are they not? Note also that a natural flavor need not come from the very food it is flavoring. For example, a flavor chemical derived from chicken -- and it need not taste like chicken -- can be used to flavor a can of beef ravioli.

An artificial flavor, on the other hand, is defined straightforwardly by the FDA as any substance that does not fit the definition of a natural flavor. Ironically, such synthetic flavoring chemicals, though unabashedly "unnatural," are acceptable in all restrictive diets from vegan to kosher, because they are neither animal nor vegetable. (I searched in vain to find any historical, philosophical or religious injunctions against the prominent artificial flavor chemical in chocolate that chemists know as 2,6-dimethylpyrazine, for example.) Furthermore, most of the chemical compounds in both artificial and natural flavors are not recognized as food by our digestive systems and are not metabolized. That's why you won't find them listed in the Nutrition Facts chart; they are not nutrients and are at any rate present in only trace amounts.

Not often realized is the fact that all flavoring additives, natural or artificial, are made by humans. To make an artificial flavor, a flavor chemist (called a flavorist) in a laboratory has to select and blend the right chemical compounds in the right amounts to simulate the natural flavor. And to obtain and concentrate the natural flavoring compounds, someone in another laboratory or factory has to extract or distill them from the raw plant or animal materials.

An even less appreciated fact is that, in many cases, the man-made flavoring chemicals are identical to Nature's flavoring chemicals. For example, the primary natural flavor compound in almonds is benzaldehyde; when our taste receptors come across a molecule of benzaldehyde, they shout "almond" to our brains. So some food manufacturers use synthesized (laboratory-made) benzaldehyde as an artificial almond flavoring. It's exactly the same chemical as in real almonds, but obtained much more cheaply than by trying to extract it from tons of nuts to qualify it as a natural flavoring.

Most flavors, however, are much more complex than that. Some 37 different chemical compounds have been identified in the flavor of mangoes, and more than 800 in the flavor and aroma of coffee. To imitate the effects of the natural flavors on the palate, a flavorist must blend a dozen or more chemicals, no single one of which hits the flavor nail directly on the head.

An interesting case is the vanilla bean, most of whose natural flavor comes from its content of about 2 percent vanillin, known to chemists by its nickname, 4-hydroxy-3- methoxy benzaldehyde. If these natural flavors are extracted into alcohol, the product may legally be labeled Pure Vanilla Extract, that is, as a "natural" flavoring. But if the product contains synthetic vanillin, which can be made by any of several processes, it must be labeled Imitation Vanilla Flavoring.

But get this: If the synthetic vanillin was made not by combining chemicals in a laboratory but by allowing bacteria to ferment ferulic acid, a chemical obtained from corn or rice, it may be labeled Natural Vanilla Flavor because fermentation is a "natural" process. The vanillin obtained by both methods, however, is absolutely identical.

The bottom-line issue is, "Does artificial vanilla flavoring taste as good as natural vanilla flavoring?" Well, in taste panels convened by Cook's Illustrated magazine, the imitation vanilla flavoring was actually preferred over the natural product. So there!

Robert L. Wolke (www.professor science.com) is professor emeritus of chemistry at the University of Pittsburgh and the author, most recently, of "What Einstein Told His Cook: Kitchen Science Explained" (W. W. Norton, hard cover, $25.95). He can be reached at wolke@pitt.edu.