DEAR DR. BLONZ: I recently purchased a bag of grated mozzarella cheese at a warehouse store. I had expected the ingredient list to read "milk, salt, enzymes," which is what you find on blocks of cheese. But this bag also included "natamycin to protect flavor" and "powdered cellulose to prevent caking." What is natamycin? Do I need to be concerned about either of these ingredients' effect on health? -- D.D., PhoeniX
DEAR D.D.: It can be troubling to see unknown ingredients on a food label: You're not quite sure what they're there for, and if they have imposing-sounding names, it is reasonable to be concerned that they might be unwholesome. Such ingredients, however, often sound more onerous than they actually are.
Natamycin is a naturally occurring antifungal preservative compound that can be used to help prevent the growth of undesirable molds or yeasts on cheese. It is used with certain cheeses because it doesn't work against the friendly bacteria that are essential for flavor development during the ripening process. It will most commonly be found on grated and sliced cheeses, due to their increased surface area. (This is one reason I prefer to buy blocks of cheese, then slice or grate them as needed.)
You can find products that don't contain this preservative, but it is doubtful that it is cause for any significant concern. The small amounts used act locally and, along with the protein in the cheese, will be denatured and destroyed during the digestive process.
The powdered cellulose is there to prevent the grated mozzarella from clumping together. This is a naturally occurring carbohydrate from plants. Cellulose, which is not digested, is the most plentiful carbohydrate substance in nature. It is actually considered to be dietary fiber, but the tiny amount needed for anti-caking won't even register on the food label.
Regarding food additives in general, you can limit the problem by sticking to whole, or minimally processed, foods. But even this is no guarantee. As a group, food additives are a mixed lot, containing a variety of substances that accomplish some rather amazing things. They are all chemicals -- one and all -- but the same can be said for all foods we eat, whether they come fresh from the garden or from a package on your grocer's shelf. The Food and Drug Administration has a reference on food additives at tinyurl.com/aub75ck, and there is another one at the U.S National Library of Medicine: tinyurl.com/hh84vuq.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.