Probably the most common FA in our foods is oleic acid, a monounsaturated FA. When hydrogenated, such as when vegetable oils are being converted into spreadable margarine, oleic acid can be changed into a trans form called elaidic acid. Elaidic acid is thus the primary trans FA that commercial hydrogenation produces.
On the other hand, the bacterial hydrogenation of oleic acid in ruminants produces a different trans form of oleic acid called vaccenic acid (from the Latin vacca, meaning "cow"). Not enough research has been done to determine whether these two kinds of trans FAs are equally detrimental to our health. The dairy and cattle industries nevertheless maintain that vaccenic acid is not only harmless, but quite possibly even healthful. That remains to be seen.
One class of (non-trans) FAs that are indeed healthful, however, is the omega-3 FAs, which have been found to decrease the risk of cardiovascular disease. (They are so named because their molecules have kinks located three carbon atoms away from the ends of their chains.) So Sheila Scheideler and other researchers at the University of Nebraska-Lincoln got the bright idea of feeding hens flaxseed and other omega-3-rich diets. And lo! their eggs came out with an average of 350 milligrams of omega-3 FAs in their yolks, compared with 60 milligrams in ordinary eggs.
These so-called Omega Eggs are now available in the markets -- at a premium price, of course. But what else would you expect of a chic, tailor-made egg sporting all but a designer label?
Robert L. Wolke is professor emeritus of chemistry at the University of Pittsburgh. (His latest book, "What Einstein Told His Cook 2: Further Adventures in Kitchen Science," will be published next month by W.W. Norton.
LABELINGO Perspicacious reader Vicky Aurich of Rockville reports that the label on Walden Farms Salad Dressing says it contains "0 fat, 0 carbs, and 0 calories." Sure enough, the Waldon Farms Web site confirms that it is "calorie free, fat free, cholesterol free, sugar free, and carbohydrate free."
Are you sure, Vicky, that the bottle wasn't empty? No, I guess not. The Web site says that it contains vinegar, spices, flavors and water. I'd be tempted to call it "salad dressing free."
Have you noticed any silly things on food labels? Send your Labelingo contributions, along with your name and town, to Food 101, Food Section, The Washington Post, 1150 15th Street, NW, Washington, D.C. 20071 or via e-mail to email@example.com.