Federal regulations require that pasteurized processed cheeses and cheese spreads contain at least 51 percent real cheese. The rest of the ingredients can range from water and salt to artificial coloring and preservatives. For example, a cheese spread such as Kraft's Cheez Whiz may contain a number of strange-sounding ingredients, including whey, sodium phosphate, whey protein concentrate, milkfat, skim milk, salt, worcestershire sauce, mustard flour, lactic acid, sorbic acid, annatto and oleoresin paprika.
Whey is a cheese byproduct. When you add an enzyme to milk to make cheese and remove the curds that form, the remaining liquid is whey. Sodium phosphate is an emulsifying agent -- the FDA limits these to no more than 3% of the total weight. Lactic acid is an acidifying agent, produced by fermenting cornstarch, or beet sugar. Sorbic acid is a common harmless preservative. And annatto and oleoresin paprika are natural food colorings.
More on processed cheeses: