Yogurt: The Curds and Whey to Health? : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

If the manufacturer heat-treats the yogurt after fermentation, the label must say "heat-treated after culturing." If the yogurt contains living bacteria, the label may say "active yogurt cultures," "living yogurt cultures," or "contains active cultures."

Don't be confused by a label that says "made with active cultures." All yogurts are made this way, but only the brands that are not heat-treated after fermentation retain their living cultures.

Freshly made yogurt with live cultures contains about 1 billion bacteria per gram, according to All About Yogurt, by William Helferich and Dennis Westhoff (Prentice-Hall, Inc., 1980). As it sits on the shelf, however, the yogurt's S. thermophilus eventually die off from the acidic environment. Refrigerated yogurt, even one to two weeks after fermentation, will probably still have about 1 million bacteria per gram.

Yogurt lasts about two weeks at home in the refrigerator. Mold and gas bubbles signal spoilage. However, greenish or clear liquid floating on top may be just the whey, a harmless liquid component of yogurt. Just mix it in before you eat it.

You can make your own yogurt cheaply. Many cookbooks explain how to make it with common utensils, but kitchen supply stores carry yogurt makers as well.

Homemade yogurt is usually quite sour, but a spoonful of jam, honey or fresh fruit will take off the edge and leave you with a pleasant, nutritious afternoon snack.

So, like Miss Muffet, pull up a tuffet and dig in. Just try to avoid the spiders.

Yogurt Lingo

A browse through the supermarket dairy case reveals a dizzying array of yogurts, with about 30 different flavors and a number of textures. Some descriptions on yogurt products are established by FDA, while others are commonly agreed upon by yogurt manufacturers.

Sundae or fruit-on-the-bottom: Fruit is on the bottom, so that if you turned it upside down, it would look like a sundae. The liquid part of the yogurt, the whey, may float on top of the solid curds. Consumers can mix them together to make it smooth and creamy.

Swiss or custard: Fruit and yogurt are mixed together and poured into individual servings. A stabilizer such as gelatin may be added for firmness or body. In some custard-style yogurt products, the fruit is placed on top of the yogurt to make a marbled effect as it settles to the bottom.

Liquid yogurt: Fruit and yogurt are blended into a drinkable liquid.

Low-fat and nonfat: FDA recognizes three standardized yogurt products. Yogurt made from whole milk has at least 3.25 percent milk fat. Low-fat yogurt is made from low-fat milk or part skim milk and has between 2 and .5 percent milk fat, while nonfat yogurt is made from skim milk and contains less than .5 percent milk fat.

Heat-treated after culturing: Yogurt has been heated after culturing to increase shelf life. The process also kills living yogurt cultures. If the product has been heat-treated after culturing, FDA requires it to say so on the label.

Contains active yogurt cultures: Yogurt labeled with this phrase has not been heat-treated after culturing and contains living yogurt cultures.

Made with active cultures: All yogurts are made with active cultures. Only those that are not heat-treated, however, retain them on the grocery shelves.

Frozen Yogurt

Frozen yogurt, like its namesake in the dairy case, must have two types of bacteria, L. bulgaricus and S. thermophilus, added during processing. Other than that, frozen yogurts may bear little resemblance to their dairy case counterparts.

For one thing, frozen yogurts are often very sweet. Tart frozen yogurts introduced in the 1970s didn't catch on with consumers looking for an ice cream substitute, according to Nan Rainey, a chemist with FDA.

Today's frozen yogurts taste more like desserts because they're not fermented as long as non-frozen yogurt. Therefore, they're less acidic than non-frozen yogurt and taste sweeter.

Frozen yogurts also may not have the same amount of living bacteria as their non-frozen counterparts. Some manufacturers make frozen yogurt by fermenting milk the traditional way, then freezing the mixture. Others make a kind of ice-milk mixture and add the bacteria later. As a result, the number of live culture organisms in frozen yogurt varies greatly between brands.

Words like "low-fat" and "nonfat" may not be consistent between brands of frozen yogurt because FDA has not established standards of identity for these food. New food label regulations proposed by the agency, however, will define these terms.

The International Ice Cream Association and the Calorie Control Council have both petitioned FDA to set standards of identity for frozen yogurts, and the agency is considering their requests.

Even without standards, however, frozen yogurt products can provide a creamy dessert, often low in fat, that mimics the flavor and texture of ice cream.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.