You can also store dried food in the freezer, another form of ensuring its safety. A good sharp knife. Pretreatment is not necessary for successful drying, but it can enhance the color, flavor, and texture of certain foods. Pretreatment options include dipping, blanching, marinating, and sulfuring. The microorganisms that cause spoilage need moisture to live and reproduce.
Foods also contain simple yeasts, molds, and bacteria, all of which can cause deterioration.
Again, reducing the moisture content of food inhibits their growth. When dried, vegetables contain only about 3 percent moisture, and fruits, depending upon sugar content, up to 15 percent water. In the most simple definition, sulfuring helps to preserve the color of some dried foods, like apricots. Fumes from burning sulfur or gaseous sulfur dioxide penetrate the surfaces of foods before they are dried. I do not sulfur the foods I dry.