Food Pretreatments and Curing

Prior to drying, some foods, such as apricots and peaches, are dipped in a sulfite solution or exposed to sulfur dioxide gas to preserve their natural color and prevent spoilage. Although sulfur protects against enzymatic browning and the loss of vitamin A and C, it destroys thiamin (vitamin B1) and may cause headaches or allergic reactions, including coma and death, in certain sensitive individuals.

Plums are briefly dipped in lye or very hot water to “check” their skins before they are dried into prunes. This process cracks the skin, thereby improving skin texture and shortening the drying time by exposing more surface area to drying. Some vegetables, such as potatoes or carrots, are blanched prior to drying to prevent enzymatic browning.

Curing Foods

One of the earliest methods of preservation was to rub the surface of meats and fish with salt. High concentrations of salt bind to the water in the food, making it unavailable to microorganisms. The earliest recorded use of salt as a preservative dates back to 3000 B.C., when salt was used to cure fish. Native Americans used salt to preserve some of their foods, the Hopi people traveled long distances to the salt mines within the Grand Canyon to obtain salt for this purpose. Corned beef is a cured meat, the word “corn” referring to the Latin word for “grain”, in this case, “grains” of salt. Today, the most commonly cured meats include ham, sausage, hot dogs, bacon, and bologna. These and other cured foods, however, should be treated as fresh foods, because they do not contain enough salt to store them on the shelf.

Cured meats sometimes undergo the optional treatment of smoking for added flavor. Meats are placed in smokers where they are exposed to the smoke of burning wood. The type of wood selected (sawdust, mesquite, hickory, oak, and various combinations) determines the resulting flavor. There are health concerns with smoked foods, however, as they have been linked to cancer in laboratory animals.