1. The common name used for potassium nitrate, a naturally occurring chemical compound that has a variety of uses, both for food and otherwise. It's used for food preservation and color retention, particularly in cured meats such as bacon, bologna, corned beef, ham, hot dogs and pepperoni, though potassium nitrate has been replaced in most cases by sodium nitrate/nitrite. It was also used in the production of ice cream; when mixed with ice it freezes foods faster than ice alone. In the non-food world, it's utilized for fireworks, gunpowder, as a component in fertilizer and so on. 2. Another chemical compound referred to as saltpeter is sodium nitrate, which appears naturally in leafy green vegetables. Like potassium nitrate, it's used to cure and retain color in meat products. Over time sodium nitrate breaks down and becomes sodium nitrite. Nitrate/nitrite compounds inhibit botulism, but generations of improved refrigeration and freezing techniques have allowed the food processing industry to reduce the use of such additives. Sodium nitrate also has a number of non-food uses. There's a common belief that saltpeter is used in prisons, the military and all-male colleges to blunt the male sex drive, which is untrue.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.